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Sample records for aureus causing bovine

  1. Prevalence of coagulase gene polymorphism in Staphylococcus aureus isolates causing bovine mastitis

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Dangler, C. A.; Sordillo, L. M.

    1995-01-01

    This study was conducted to investigate polymorphism of the coagulase gene of Staphylococcus aureus causing bovine mastitis. One hundred eighty-seven strains of S. aureus were isolated from bovine mastitic milk samples obtained from 187 different Danish dairy farms. The isolates were characterised......% of the isolates. The ease of analysing coagulase gene polymorphisms among a large number of strains, and the multiple distinct polymorphic patterns generated, supports the use of this technique in epidemiological investigations of bovine mastitis. The predominating variants may have predelection for causing...

  2. Molecular Characteristics of Staphylococcus aureus Causing Bovine Mastitis between 2014 and 2015.

    Science.gov (United States)

    Li, Tianming; Lu, Huiying; Wang, Xing; Gao, Qianqian; Dai, Yingxin; Shang, Jun; Li, Min

    2017-01-01

    Staphylococcus aureus is highly pathogenic and can cause diseases in both humans and domestic animals. In animal species, including ruminants, S. aureus may cause severe or sub-clinical mastitis. This study aimed to investigate the molecular profile, antimicrobial resistance, and genotype/phenotype correlation of 212 S. aureus isolates recovered from cases of bovine mastitis from 2014 to 2015 in the Shanghai and Zhejiang areas of China. Nineteen sequence types (STs) were determined by multi-locus sequence typing, while the dominant ST was ST97, followed by ST520, ST188, ST398, ST7, and ST9. Within 14 methicillin-resistant S. aureus (MRSA) isolates and 198 methicillin-susceptible S. aureus (MSSA) isolates, ST97 was the predominant MSSA clone and ST9-MRSA-SCCmecXII-spa t899 was the most common MRSA clone. The MRSA strains showed much higher rates of resistance to multiple antibiotics than did MSSA strains. Compared with other MSSA strains, MSSA ST398 was more resistant to clindamycin, erythromycin, and ciprofloxacin. No isolates were resistant to vancomycin, teicoplanin, or linezolid. The molecular profiles of the virulence genes varied in different strains. ST520 strains carried seg-sei-sem-sen-seo genes, and ST9 and ST97 harbored sdrD-sdrE genes. Virulence phenotype analysis showed diversity in different clones. Biofilm formation ability was significantly enhanced in ST188 and ST7, and red blood cell lysis capacity was relatively strong in all S. aureus strains of animal origin except ST7. Our results indicate that MSSA was the predominant S. aureus strain causing bovine mastitis in eastern regions of China. However, the presence of multidrug resistant and toxigenic MRSA clone ST9 suggests that comprehensive surveillance of S. aureus infection should be implemented in the management of animal husbandry products.

  3. Bovine mastitis outbreak in Japan caused by methicillin-resistant Staphylococcus aureus New York/Japan clone.

    Science.gov (United States)

    Hata, Eiji

    2016-05-01

    Many methicillin-resistant Staphylococcus aureus (MRSA) strains are multidrug-resistant; consequently, infectious diseases involving MRSA are recognized as troublesome diseases not only in human health care but also in animal health care. A bovine mastitis case caused by MRSA isolates of the New York/Japan clone (NJC), which occurred in Japan in 2005, was monitored in the current study. Isolates of the NJC are typical of hospital-acquired MRSA in Japan. The genetic backgrounds of these strains differ from those of bovine-associated S. aureus, which are typically of clonal complex (CC)97, CC705, and CC133. Moreover, the NJC isolates in this bovine outbreak possessed a β-hemolysin-converting bacteriophage and an immune evasion cluster, as found in the NJC isolates from humans, so it is possible that this clone was introduced into the dairy herd by a human carrier. Most bovine intramammary infections (IMIs) caused by the NJC isolates in our study were asymptomatic, and obvious clinical signs were recognized in only the first 3 infected cows. Of a total of 78 cows, 31 cows were MRSA carriers, and these carrier cows were detected by testing the milk of all lactating cows at 1-month intervals. These S. aureus carrier cows were culled or the infected quarter was dried off and no longer milked. Both IMI and mastitis caused by MRSA were completely eradicated after 5 months. Genotyping data suggested that exchanging of the staphylococcal cassette chromosome mec (the determining factor in methicillin resistance) occurred easily between MRSA and methicillin-sensitive S. aureus in the udders of carrier cows. This case study demonstrates an effective procedure against the spread of MRSA in a dairy herd, and highlights the risk of emergence of new MRSA strains in a dairy herd. © 2016 The Author(s).

  4. Exfoliation rate of mammary epithelial cells in milk on bovine mastitis caused by Staphylococcus aureus is associated with bacterial load.

    Science.gov (United States)

    Nagasawa, Yuya; Kiku, Yoshio; Sugawara, Kazue; Tanabe, Fuyuko; Hayashi, Tomohito

    2018-01-01

    The exfoliation rate of mammary epithelial cells (MECs) in milk is affected by physiological, breeding and environmental factors. Little is known about the relationship between the MEC exfoliation into milk and mammary-infected Staphylococcus aureus (S. aureus) load on bovine mastitis caused by S. aureus. The aim of this study was to investigate the relationship between S. aureus load and the proportion of MEC exfoliation in milk using five substantial bovine mastitis models. In 64 randomly extracted milk samples from udders at 3-21 days after S. aureus infusion, there were various samples with different numbers of S. aureus counts and somatic cell counts. No significant correlations were found between the S. aureus counts and somatic cell count (r = 0.338). In contrast, a significant correlation was noted between S. aureus counts and the proportion of cytokeratin-positive cells in the milk from the infused udders (r = 0.734, P mastitis udders caused by S. aureus may contribute to reduced milk yield. © 2017 Japanese Society of Animal Science.

  5. Bacteriocins of Non-aureus Staphylococci Isolated from Bovine Milk

    Science.gov (United States)

    Carson, Domonique A.; Barkema, Herman W.; Naushad, Sohail

    2017-01-01

    ABSTRACT Non-aureus staphylococci (NAS), the bacteria most commonly isolated from the bovine udder, potentially protect the udder against infection by major mastitis pathogens due to bacteriocin production. In this study, we determined the inhibitory capability of 441 bovine NAS isolates (comprising 26 species) against bovine Staphylococcus aureus. Furthermore, inhibiting isolates were tested against a human methicillin-resistant S. aureus (MRSA) isolate using a cross-streaking method. We determined the presence of bacteriocin clusters in NAS whole genomes using genome mining tools, BLAST, and comparison of genomes of closely related inhibiting and noninhibiting isolates and determined the genetic organization of any identified bacteriocin biosynthetic gene clusters. Forty isolates from 9 species (S. capitis, S. chromogenes, S. epidermidis, S. pasteuri, S. saprophyticus, S. sciuri, S. simulans, S. warneri, and S. xylosus) inhibited growth of S. aureus in vitro, 23 isolates of which, from S. capitis, S. chromogenes, S. epidermidis, S. pasteuri, S. simulans, and S. xylosus, also inhibited MRSA. One hundred five putative bacteriocin gene clusters encompassing 6 different classes (lanthipeptides, sactipeptides, lasso peptides, class IIa, class IIc, and class IId) in 95 whole genomes from 16 species were identified. A total of 25 novel bacteriocin precursors were described. In conclusion, NAS from bovine mammary glands are a source of potential bacteriocins, with >21% being possible producers, representing potential for future characterization and prospective clinical applications. IMPORTANCE Mastitis (particularly infections caused by Staphylococcus aureus) costs Canadian dairy producers $400 million/year and is the leading cause of antibiotic use on dairy farms. With increasing antibiotic resistance and regulations regarding use, there is impetus to explore bacteriocins (bacterially produced antimicrobial peptides) for treatment and prevention of bacterial infections

  6. Methicillin resistant S. aureus in human and bovine mastitis.

    Science.gov (United States)

    Holmes, Mark A; Zadoks, Ruth N

    2011-12-01

    Staphylococcus aureus is a ubiquitous organism that causes a variety of diseases including mastitis in cattle and humans. High-level resistance of S. aureus to β-lactams conferred by a mecA gene encoding a modified penicillin binding protein (PBP2a) was first observed in the early 1960's. These methicillin resistant S. aureus (MRSA) have been responsible for both hospital acquired infections (HA-MRSA) and, more recently, community acquired MRSA (CA-MRSA). A small number of human MRSA mastitis cases and outbreaks in maternity or neonatal units have been reported which are generally the result of CA-MRSA. The establishment of the sequence type 398 (ST398) in farm animals, primarily pigs, in the early 2000's has provided a reservoir of infection for humans and dairy cattle, particularly in continental Europe, described as livestock-associated MRSA (LA-MRSA). Prior to the emergence of ST398 there were sporadic reports of MRSA in bovine milk and cases of mastitis, often caused by strains from human associated lineages. Subsequently, there have been several reports describing bovine udder infections caused by ST-398 MRSA. Recently, another group of LA-MRSA strains was discovered in humans and dairy cattle in Europe. This group carries a divergent mecA gene and includes a number of S. aureus lineages (CC130, ST425, and CC1943) that were hitherto thought to be bovine-specific but are now also found as carriage or clinical isolates in humans. The emergence of MRSA in dairy cattle may be associated with contact with other host species, as in the case of ST398, or with the exchange of genetic material between S. aureus and coagulase negative Staphylococcus species, which are the most common species associated with bovine intramammary infections and commonly carry antimicrobial resistance determinants.

  7. Bacteriocins of Non-aureus Staphylococci Isolated from Bovine Milk.

    Science.gov (United States)

    Carson, Domonique A; Barkema, Herman W; Naushad, Sohail; De Buck, Jeroen

    2017-09-01

    Non- aureus staphylococci (NAS), the bacteria most commonly isolated from the bovine udder, potentially protect the udder against infection by major mastitis pathogens due to bacteriocin production. In this study, we determined the inhibitory capability of 441 bovine NAS isolates (comprising 26 species) against bovine Staphylococcus aureus Furthermore, inhibiting isolates were tested against a human methicillin-resistant S. aureus (MRSA) isolate using a cross-streaking method. We determined the presence of bacteriocin clusters in NAS whole genomes using genome mining tools, BLAST, and comparison of genomes of closely related inhibiting and noninhibiting isolates and determined the genetic organization of any identified bacteriocin biosynthetic gene clusters. Forty isolates from 9 species ( S. capitis , S. chromogenes , S. epidermidis , S. pasteuri , S. saprophyticus , S. sciuri , S. simulans , S. warneri , and S. xylosus ) inhibited growth of S. aureus in vitro , 23 isolates of which, from S. capitis , S. chromogenes , S. epidermidis , S. pasteuri , S. simulans , and S. xylosus , also inhibited MRSA. One hundred five putative bacteriocin gene clusters encompassing 6 different classes (lanthipeptides, sactipeptides, lasso peptides, class IIa, class IIc, and class IId) in 95 whole genomes from 16 species were identified. A total of 25 novel bacteriocin precursors were described. In conclusion, NAS from bovine mammary glands are a source of potential bacteriocins, with >21% being possible producers, representing potential for future characterization and prospective clinical applications. IMPORTANCE Mastitis (particularly infections caused by Staphylococcus aureus ) costs Canadian dairy producers $400 million/year and is the leading cause of antibiotic use on dairy farms. With increasing antibiotic resistance and regulations regarding use, there is impetus to explore bacteriocins (bacterially produced antimicrobial peptides) for treatment and prevention of bacterial

  8. Bovine origin Staphylococcus aureus: A new zoonotic agent?

    Science.gov (United States)

    Rao, Relangi Tulasi; Jayakumar, Kannan; Kumar, Pavitra

    2017-10-01

    The study aimed to assess the nature of animal origin Staphylococcus aureus strains. The study has zoonotic importance and aimed to compare virulence between two different hosts, i.e., bovine and ovine origin. Conventional polymerase chain reaction-based methods used for the characterization of S. aureus strains and chick embryo model employed for the assessment of virulence capacity of strains. All statistical tests carried on R program, version 3.0.4. After initial screening and molecular characterization of the prevalence of S. aureus found to be 42.62% in bovine origin samples and 28.35% among ovine origin samples. Meanwhile, the methicillin-resistant S. aureus prevalence is found to be meager in both the hosts. Among the samples, only 6.8% isolates tested positive for methicillin resistance. The biofilm formation quantified and the variation compared among the host. A Welch two-sample t -test found to be statistically significant, t=2.3179, df=28.103, and p=0.02795. Chicken embryo model found effective to test the pathogenicity of the strains. The study helped to conclude healthy bovines can act as S. aureus reservoirs. Bovine origin S. aureus strains are more virulent than ovine origin strains. Bovine origin strains have high probability to become zoonotic pathogen. Further, gene knock out studies may be conducted to conclude zoonocity of the bovine origin strains.

  9. LukMF′ is the major secreted leukocidin of bovine Staphylococcus aureus and is produced in vivo during bovine mastitis

    Science.gov (United States)

    Vrieling, Manouk; Boerhout, Eveline M.; van Wigcheren, Glenn F.; Koymans, Kirsten J.; Mols-Vorstermans, Tanja G.; de Haas, Carla J. C.; Aerts, Piet C.; Daemen, Ineke J. J. M.; van Kessel, Kok P. M.; Koets, Ad P.; Rutten, Victor P. M. G.; Nuijten, Piet J.M.; van Strijp, Jos A. G.; Benedictus, Lindert

    2016-01-01

    Staphylococcus aureus is a major human and animal pathogen and a common cause of mastitis in cattle. S. aureus secretes several leukocidins that target bovine neutrophils, crucial effector cells in the defence against bacterial pathogens. In this study, we investigated the role of staphylococcal leukocidins in the pathogenesis of bovine S. aureus disease. We show that LukAB, in contrast to the γ-hemolysins, LukED, and LukMF′, was unable to kill bovine neutrophils, and identified CXCR2 as a bovine receptor for HlgAB and LukED. Furthermore, we assessed functional leukocidin secretion by bovine mastitis isolates and observed that, although leukocidin production was strain dependent, LukMF′ was most abundantly secreted and the major toxin killing bovine neutrophils. To determine the role of LukMF′ in bovine mastitis, cattle were challenged with high (S1444) or intermediate (S1449, S1463) LukMF′-producing isolates. Only animals infected with S1444 developed severe clinical symptoms. Importantly, LukM was produced in vivo during the course of infection and levels in milk were associated with the severity of mastitis. Altogether, these findings underline the importance of LukMF′ as a virulence factor and support the development of therapeutic approaches targeting LukMF′ to control S. aureus mastitis in cattle. PMID:27886237

  10. Bovine Staphylococcus aureus secretes the leukocidin LukMF′ to kill migrating neutrophils through CCR1

    NARCIS (Netherlands)

    Vrieling, M.; Koymans, K.J.; Heesterbeek, D.A.C.; Aerts, P.C.; Rutten, V.P.M.G.; de Haas, C.J.C.; van Kessel, K.P.M.; Koets, A.P.; Nijland, R; van Strijp, J.A.G.

    2015-01-01

    Although Staphylococcus aureus is best known for infecting humans, bovine-specific strains are a major cause of mastitis in dairy cattle. The bicomponent leukocidin LukMF′, exclusively harbored by S. aureus of ruminant origin, is a virulence factor associated with bovine infections. In this study,

  11. Bovine Staphylococcus aureus secretes the leukocidin LukMF' to kill migrating neutrophils through CCR1

    NARCIS (Netherlands)

    Vrieling, M.; Koymans, K.J.; Heesterbeek, D.A.C.; Aerts, P.C.; Rutten, V.P.M.G.; Haas, de C.J.C.; Kessel, van K.P.M.; Koets, A.P.; Nijland, R.; Strijp, van J.A.G.

    2015-01-01

    Although Staphylococcus aureus is best known for infecting humans, bovine-specific strains are a major cause of mastitis in dairy cattle. The bicomponent leukocidin LukMF′, exclusively harbored by S. aureus of ruminant origin, is a virulence factor associated with bovine infections. In this study,

  12. LukMF′ is the major secreted leukocidin of bovine Staphylococcus aureus and is produced in vivo during bovine mastitis

    NARCIS (Netherlands)

    Vrieling, Manouk; Boerhout, Eveline M.; Van Wigcheren, Glenn F.; Koymans, Kirsten J.; Mols-Vorstermans, Tanja G.; de Haas, Carla J C; Aerts, Piet C.; Daemen, Ineke J J M; van Kessel, Kok P M; Koets, Ad P.; Rutten, Victor P M G; Nuijten, Piet J M; Van Strijp, Jos A G; Benedictus, Lindert

    2016-01-01

    Staphylococcus aureus is a major human and animal pathogen and a common cause of mastitis in cattle. S. aureus secretes several leukocidins that target bovine neutrophils, crucial effector cells in the defence against bacterial pathogens. In this study, we investigated the role of staphylococcal

  13. LukMF' is the major secreted leukocidin of bovine Staphylococcus aureus and is produced in vivo during bovine mastitis

    NARCIS (Netherlands)

    Vrieling, Manouk; Boerhout, Eveline M; van Wigcheren, Glenn F; Koymans, Kirsten J; Mols-Vorstermans, Tanja G; de Haas, Carla J C; Aerts, Piet C; Daemen, Ineke J J M; van Kessel, Kok P M; Koets, Ad P|info:eu-repo/dai/nl/194306992; Rutten, Victor P M G|info:eu-repo/dai/nl/092848028; Nuijten, Piet J M; van Strijp, Jos A G; Benedictus, Lindert|info:eu-repo/dai/nl/37157742X

    2016-01-01

    Staphylococcus aureus is a major human and animal pathogen and a common cause of mastitis in cattle. S. aureus secretes several leukocidins that target bovine neutrophils, crucial effector cells in the defence against bacterial pathogens. In this study, we investigated the role of staphylococcal

  14. LukMF′ is the major secreted leukocidin of bovine Staphylococcus aureus and is produced in vivo during bovine mastitis

    NARCIS (Netherlands)

    Vrieling, Manouk; Boerhout, Eveline M.; Wigcheren, Van Glenn F.; Koymans, Kirsten J.; Mols-Vorstermans, Tanja G.; Haas, de Carla J.C.; Aerts, Piet C.; Daemen, Ineke J.J.M.; Kessel, Van Kok P.M.; Koets, Ad P.; Rutten, Victor P.M.G.; Nuijten, Piet J.M.; Strijp, van Jos A.G.; Benedictus, Lindert

    2016-01-01

    Staphylococcus aureus is a major human and animal pathogen and a common cause of mastitis in cattle. S. aureus secretes several leukocidins that target bovine neutrophils, crucial effector cells in the defence against bacterial pathogens. In this study, we investigated the role of staphylococcal

  15. Association between phage types and antimicrobial resistance among bovine Staphylococcus aureus from 10 countries

    DEFF Research Database (Denmark)

    Vintov, J.; Aarestrup, Frank Møller; Zinn, C. E.

    2003-01-01

    This study was conducted to investigate the diversity of phage types and associations between penicillin resistance and phage types among 815 Staphylococcus aureus isolates from bovine mastitis in nine European countries and USA. All isolates were examined for susceptibility to antimicrobial agents...... associated with penicillin resistance in contrast to phage group I (P = 0.0023) and phage complex-80 (P = 0.0066). This study confirms that a large number of phage types of S. aureus cause bovine mastitis, but that some types predominate. In addition, these findings could indicate that the use of penicillin...... in the bovine environment has selected for specific types of S. aureus in countries with a high frequency of resistance....

  16. Preliminary treatment of bovine mastitis caused by Staphylococcus aureus, with trx-SA1, recombinant endolysin of S. aureus bacteriophage IME-SA1.

    Science.gov (United States)

    Fan, Jindai; Zeng, Zhiliang; Mai, Kaijie; Yang, Yu; Feng, Jiaqi; Bai, Yang; Sun, Baoli; Xie, Qingmei; Tong, Yigang; Ma, Jingyun

    2016-08-15

    Methicillin-resistant Staphylococcus aureus (MRSA) has become a great threat to human and animal health and there is an urgent need to develop novel antibacterial agents to control this pathogen. The objective of this study was to obtain an active recombinant endolysin from the novel bacteriophage (IME-SA1), and conduct an efficacy trial of its effectiveness against bovine mastitis. We isolated a phage that was virulent and specific for S. aureus with an optimal multiplicity of infection of 0.01. Electron microscopy revealed that IME-SA1 was a member of the family Myoviridae, with an isometric head (98nm) and a long contractile tail (200nm). Experimental lysis experiments indicated the phage had an incubation period of 20min with a burst size of 80. When host bacteria were in early exponential growth stages, a multiplicity of infection of 0.01 resulted in a complete bacterial lysis after 9h. The endolysin gene (804bp) was cloned into the pET-32a bacterial expression vector and recombinant endolysin Trx-SA1 was successfully obtained with molecular size of about 47kDa. Preliminary results of therapeutic trials in cow udders showed that Trx-SA1 could effectively control mild clinical mastitis caused by S. aureus. The endolysin Trx-SA1 might be an alternative treatment strategy for infections caused by S. aureus, including MRSA. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Host adaptation of bovine Staphylococcus aureus seems associated with bacteriological cure after lactational antimicrobial treatment

    NARCIS (Netherlands)

    Borne, van den B.H.P.; Nielen, M.; Schaik, van G.; Melchior, M.B.; Lam, T.J.G.M.; Zadoks, R.N.

    2010-01-01

    Staphylococcus aureus causes a wide range of diseases in multiple species. Some sequence types (ST) are observed in a variety of hosts, whereas other strains are mainly associated with bovine mastitis, suggesting host adaptation. We propose that host adaptation of Staph. aureus may influence

  18. Association between phage types and antimicrobial resistance among bovine isolates of Staphylococcus aureus in 10 countries

    DEFF Research Database (Denmark)

    Vintov, J.; Aarestrup, Frank Møller; Zinn, C. E.

    2003-01-01

    This study was conducted to investigate the diversity of phage types and associations between penicillin resistance and phage types among 815 Staphylococcus aureus isolates from bovine mastitis in nine European countries and USA. All isolates were examined for susceptibility to antimicrobial agents...... associated with penicillin resistance in contrast to phage group I (P = 0.0023) and phage complex-80 (P = 0.0066). This study confirms that a large number of phage types of S. aureus cause bovine mastitis, but that some types predominate. In addition, these findings could indicate that the use of penicillin...... in the bovine environment has selected for specific types of S. aureus in countries with a high frequency of resistance. (C) 2003 Elsevier B.V. All rights reserved....

  19. Short communication: Antimicrobial susceptibility profiling and genotyping of Staphylococcus aureus isolates from bovine mastitis in Poland.

    Science.gov (United States)

    Jagielski, T; Puacz, E; Lisowski, A; Siedlecki, P; Dudziak, W; Międzobrodzki, J; Krukowski, H

    2014-10-01

    Staphylococcus aureus is the predominant causative agent of bovine mastitis, a disease that remains a major economic burden for the dairy industry worldwide. In this study, the antimicrobial resistance patterns and the genetic composition of 80 S. aureus mastitis isolates collected from 14 dairy farms in Eastern Poland were determined. Of the 10 antimicrobial agents evaluated, only testing for penicillin G produced drug resistance. As 41% of the S. aureus isolates were penicillin resistant, this drug along with other β-lactamase-sensitive β-lactams, should rather not be considered for the treatment of bovine mastitis caused by S. aureus. Upon genotyping, with a triplex PCR method, a total of 11 distinct PCR types were produced. The population structure of S. aureus isolates was highly clonal, with 1 predominant genotype circulating on each farm. The observed similarities in the genotype composition of S. aureus populations from geographically distant farms underscore the significance of interfarm transmission of S. aureus in Poland. This, in turn, argues for the establishment of a nationwide surveillance program for bovine mastitis due to this pathogen. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  20. A study of phage- and ribotype patterns of Staphylococcus aureus isolated from bovine mastitis in the Nordic countries

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Wegener, Henrik Caspar; Jensen, N.E.

    1997-01-01

    This study was conducted to investigate the geographical distribution of phage and ribotypes of Staphylococcus aureus causing bovine mastitis in the 5 Nordic countries. A total of 403 isolates of S. aureus was isolated from 403 different dairy herds. One hundred five strains were isolated...... of the isolates of ribotype 1 belonged to phage type 29/52. This combined type accounted for 17% of all the 403 isolates. These findings show that a large number of different types of S. aureus can be isolated from cases of bovine mastitis. However, few types predominate within different countries....... These predominating types seem to be specific in each country, however, a single type was common for both Denmark, Sweden and Finland. This could suggest differences in the virulence or in modes of transmission of predominating and rare types of S. aureus associated with bovine mastitis....

  1. Identification of Staphylococus aureus genes expressed during growth in milk : a useful model for selection of genes important in bovine mastitis?

    NARCIS (Netherlands)

    Lammers, A.; Kruijt, E.; Kuijt, van de C.; Nuijten, P.J.M.; Smith, H.E.

    2000-01-01

    Staphylococcus aureus is a major cause of bovine mastitis. Since gene expression of many bacteria is known to be regulated by the environment, milk may play an important role in the regulation of the early steps in the pathogenesis of bovine mastitis by S. aureus. To get insight into the response of

  2. Antimicrobial susceptibility of Staphylococcus aureus causing bovine mastitis in Argentine dairy herds Sensibilidad a los antimicrobianos de Staphylococcus aureus causantes de mastitis bovina en rodeos lecheros de Argentina

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    N.B. Russi

    2008-06-01

    Full Text Available We assessed the in vitro activity of selected antimicrobial agents against 95 Staphylococcus aureus strains causing both clinical and subclinical bovine mastitis belonging to 61 dairy farms from the Central dairy area of Argentina. Minimal inhibitory concentrations (MICs of penicillin, oxacillin, gentamicin, erythromycin, enrofloxacin and florfenicol were estimated. In addition, the agar diffusion test was performed. MIC50 and MIC90 were as follows: penicillin, 0.05 and 4 µg/ml; oxacillin, 0.25 and 0.25 µg/ml; gentamicin, 0.25 and 0.5 µg/ml; erythromycin 0.125 and 0.25 µg/ml; enrofloxacin 0.25 and 0.5 µg/ml, and florfenicol 4 and 8 µg/ml. b-lactamase activity was detected in 89% of 46 penicillin- resistant strains. Apart from penicillin, antimicrobial resistance in S. aureus causing bovine mastitis remains rare in Argentine dairy farms.Se evaluó la actividad in vitro de un grupo seleccionado de antimicrobianos contra 95 aislamientos de Staphylococcus aureus obtenidos de casos de mastitis bovina clínica y subclínica, en 61 rodeos lecheros de la cuenca central de Argentina. Fueron estimadas las concentraciones inhibitorias mínimas (CIM de penicilina, oxacilina, gentamicina, eritromicina, enrofloxacina y florfenicol. Además se realizó la prueba de difusión en agar. Las CIM50 y CIM90 obtenidas fueron: penicilina 0,05 y 4 µg/ml; oxacilina 0,25 y 0,25 µg/ml; gentamicina 0,25 y 0,5 µg/ml; eritromicina 0,125 y 0,25 µg/ml; enrofloxacina 0,25 y 0,5 µg/ml y florfenicol 4 y 8 µg/ml. Se detectó actividad de b-lactamasa en el 89% de las cepas resistentes a la penicilina. A excepción de lo observado para penicilina, la resistencia a los antimicrobianos en S. aureus causantes de mastitis bovina en Argentina parece ser un fenómeno poco frecuente.

  3. Screening method for Staphylococcus aureus identification in subclinical bovine mastitis from dairy farms

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    Natapol Pumipuntu

    2017-07-01

    Full Text Available Background: Staphylococcus aureus is one of the most important contagious bacteria causing subclinical bovine mastitis. This bacterial infection is commonly identified by determine the pathogen in bovine milk samples through conventional technique including coagulase test. However, this test has several disadvantages as low sensitivity, risk of biohazard, cost expensive, and limited preparation especially in local area. Aim: Aim of this study was to compare and assess the screening method, Mannitol fermentation test (Mannitol salt agar [MSA], and deoxyribonuclease (DNase test, for S. aureus identification in milk samples. Materials and Methods: A total of 224 subclinical bovine mastitis milk samples were collected from four provinces of Thailand and determined S. aureus using conventional method and also subjected to the screening test, MSA and DNase test. The sensitivity, specificity, positive predictive value (PPV, and negative predictive value (NPV among both tests were analyzed and compared to the tube coagulase test (TCT, as reference method. Immunological test by latex agglutination and molecular assay by determined spa gene were also used to identify and differentiate S. aureus. Results: A total of 130 staphylococci were isolated by selective media, Gram-stain, and catalase test. The number of S. aureus which identified using TCT, MSA and DNase test were 32, 102, and 74 isolates, respectively. All TCT results were correlated to results of latex agglutination and spa gene which were 32 S. aureus. MSA showed 100% sensitivity, 28.57% specificity, 31.37% PPV, and 100% NPV, whereas DNase showed 53.13% sensitivity, 41.84% specificity, 22.97% PPV, and 73.21% NPV. DNase test showed higher specificity value than MSA but the test presented 26.79% false negative results whereas no false-negative result from MSA when comparing to TCT. Conclusion: MSA had a tendency to be a good preference for screening S. aureus because of its high sensitivity and

  4. Mastitis Bovina: Resistencia a antibióticos de cepas de Staphylococcus aureus asiladas de leche (Bovine Mastitis: Antimicrobial resistance of Staphylococcus aureus strains isolated from milk)

    OpenAIRE

    Pellegrino, MS; Frola, ID; Odierno, LM; Bogni, CI

    2011-01-01

    ResumenLa mastitis bovina es considerada la enfermedad infecciosa del ganado lechero de mayor impacto económico mundial, siendo Staphylococcus aureus el principal agente patógeno en muchos países.SummaryBovine mastitis is a frequent cause of economic loss in worldwide dairy herds, being Staphylococcus aureus the main etiological agent in many countries.

  5. PCR assay with host specific internal control forStaphylococcus aureus from bovine milk samples

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    Zafer Cantekin

    2015-03-01

    Full Text Available Staphylococcus aureus is considered as one of the most important and common pathogens of bovine mastitis. Polymerase Chain Reaction is frequently proposed in the diagnosis of S. aureus directly from milk samples instead of classical culture. However, false-negative results may occur in the polymerase chain reaction analysis performed directly from clinical material. For the purpose of disclosing the false negative results, the use of internal amplification controls can be beneficial. Therefore, in this study a new polymerase chain reaction technique with host specific internal amplification control was developed by optimizing S. aureus-specific primers in combination with bovine specific primers. The effectiveness of the developed technique in this study was attempted in milk samples from bovine subclinical mastitis. This technique has the potential to detect S. aureus from bovine milk samples or dairy products.

  6. Prevalence and Characterization of Oxacillin Susceptible mecA-Positive Clinical Isolates of Staphylococcus aureus Causing Bovine Mastitis in India.

    Directory of Open Access Journals (Sweden)

    Hiral Mistry

    Full Text Available Bovine mastitis caused by multidrug resistant Staphylococcus aureus is a huge problem reported worldwide, resulting in prolonged antibiotic treatment and death of livestock. The current study is focused on surveillance of antibiotic susceptibility along with genotypic and phenotypic characterization of the pathogenic S. aureus strains causing mastitis in India. One hundred and sixty seven milk samples were collected from mastitis-affected cows from different farms in India resulting in thirty nine isolated S. aureus strains. Antibiotic sensitivity profiling revealed the majority of the strains (n = 24 to be multidrug resistant and eleven strains showed reduced susceptibility to vancomycin (MICs = 2μg/ml. All strains were oxacillin sensitive, but 19 strains were positive for the mecA gene, which revealed the occurrence of oxacillin susceptible mecA positive strains (OS-MRSA for the first time from India. Additionally, 32 strains were positive for the pvl gene, a virulence determinant; of these 17 were also OS-MRSA strains. Molecular characterization based on multilocus sequence typing (MLST, spa typing, agr typing and SCCmec classification revealed strains belonging to different groups. Moreover, strains showed spa types (t2526, t9602 and MLST sequence types, ST-72, ST-88 and ST-239 which have been earlier reported in human infections. The prevalence of OS-MRSA strains indicates the importance of including both the genetic and phenotypic tests in characterizing S. aureus strains. Increased genotypic variability with strain related to human infections and pvl positive isolates indicates a worrisome situation with the possibility of bilateral transfer.

  7. Prevalence and Characterization of Oxacillin Susceptible mecA-Positive Clinical Isolates of Staphylococcus aureus Causing Bovine Mastitis in India.

    Science.gov (United States)

    Mistry, Hiral; Sharma, Paresh; Mahato, Sudipta; Saravanan, R; Kumar, P Anand; Bhandari, Vasundhra

    2016-01-01

    Bovine mastitis caused by multidrug resistant Staphylococcus aureus is a huge problem reported worldwide, resulting in prolonged antibiotic treatment and death of livestock. The current study is focused on surveillance of antibiotic susceptibility along with genotypic and phenotypic characterization of the pathogenic S. aureus strains causing mastitis in India. One hundred and sixty seven milk samples were collected from mastitis-affected cows from different farms in India resulting in thirty nine isolated S. aureus strains. Antibiotic sensitivity profiling revealed the majority of the strains (n = 24) to be multidrug resistant and eleven strains showed reduced susceptibility to vancomycin (MICs = 2μg/ml). All strains were oxacillin sensitive, but 19 strains were positive for the mecA gene, which revealed the occurrence of oxacillin susceptible mecA positive strains (OS-MRSA) for the first time from India. Additionally, 32 strains were positive for the pvl gene, a virulence determinant; of these 17 were also OS-MRSA strains. Molecular characterization based on multilocus sequence typing (MLST), spa typing, agr typing and SCCmec classification revealed strains belonging to different groups. Moreover, strains showed spa types (t2526, t9602) and MLST sequence types, ST-72, ST-88 and ST-239 which have been earlier reported in human infections. The prevalence of OS-MRSA strains indicates the importance of including both the genetic and phenotypic tests in characterizing S. aureus strains. Increased genotypic variability with strain related to human infections and pvl positive isolates indicates a worrisome situation with the possibility of bilateral transfer.

  8. Relationships among superantigen toxin gene profiles, genotypes, and pathogenic characteristics of Staphylococcus aureus isolates from bovine mastitis.

    Science.gov (United States)

    Wang, Dong; Zhang, Limei; Yong, Changfu; Shen, Mingliang; Ali, Tariq; Shahid, Muhammad; Han, Kun; Zhou, Xuezhang; Han, Bo

    2017-06-01

    Staphylococcus aureus is one of the major etiological agents of bovine mastitis, harboring a wide variety of staphylococcal superantigen (SAg) toxin genes. The SAg toxin genes are reported to be closely associated with the pathogenicity of the Staph. aureus causing the bovine mastitis. This study was conducted to investigate SAg toxin gene profiles and to assess the relationships among SAg toxin genes, genotypes of Staph. aureus, and their pathogenic properties. A total of 327 quarter milk samples were collected from bovine mastitis cases for isolation and identification of pathogens. In total, 35 isolates were identified as Staph. aureus, and the prevalence of Staph. aureus in milk samples was 13.6% (35/256). Polymerase chain reaction (PCR) and randomly amplified polymorphic DNA (RAPD) assays were used to detect the SAg toxin genes and to genotype Staph. aureus strains isolated from milk samples of bovine mastitis in 10 dairy herds located in Ningxia, China, respectively. The results showed that among the Staph. aureus isolates (n = 35), 71.4% (n = 25) of isolates carried at least one SAg toxin gene. In total, 18 SAg genes and 21 different gene combination patterns were detected among these isolates. The most common SAg genes in Staph. aureus isolates were sei, sen, and seu (44.0% each), followed by seo, tst, and etB (28.0% each), etA (24.0%), sem and sep (16.0% each), seb, sec, sed, and sek (12.0% each), and sea and seh genes (8.0% each); the seg, sej, and ser genes were present in 4.0% of the isolates. Three gene combinations were found to be related to mobile genetic elements that carried 2 or more genes. The egc-cluster of the seg-sei-sem-sen-seo genes, located on the pathogenicity island Type I υSaβ, was detected in 16% of isolates. Interestingly, we observed 6 RAPD genotypes (I to VI) in Staph. aureus isolates, and 2 of these genotypes were strongly associated with the severity of bovine mastitis; there was a close relationship between the RAPD genotypes

  9. Host-pathogen interactions in bovine mammary epithelial cells and HeLa cells by Staphylococcus aureus isolated from subclinical bovine mastitis.

    Science.gov (United States)

    Castilho, Ivana G; Dantas, Stéfani Thais Alves; Langoni, Hélio; Araújo, João P; Fernandes, Ary; Alvarenga, Fernanda C L; Maia, Leandro; Cagnini, Didier Q; Rall, Vera L M

    2017-08-01

    Staphylococcus aureus is a common pathogen that causes subclinical bovine mastitis due to several virulence factors. In this study, we analyzed S. aureus isolates collected from the milk of cows with subclinical mastitis that had 8 possible combinations of bap, icaA, and icaD genes, to determine their capacity to produce biofilm on biotic (bovine primary mammary epithelial cells and HeLa cells) and abiotic (polystyrene microplates) surfaces, and their ability to adhere to and invade these cells. We also characterized isolates for microbial surface components recognizing adhesive matrix molecules (MSCRAMM) and agr genes, and for their susceptibility to cefquinome sulfate in the presence of biofilm. All isolates adhered to and invaded both cell types, but invasion indexes were higher in bovine primary mammary epithelial cells. Using tryptic soy broth + 1% glucose on abiotic surfaces, 5 out of 8 isolates were biofilm producers, but only the bap + icaA + icaD + isolate was positive in Dulbecco's Modified Eagle's medium. The production of biofilm on biotic surfaces occurred only with this isolate and only on HeLa cells, because the invasion index for bovine primary mammary epithelial cells was too high, making it impossible to use these cells in this assay. Of the 5 biofilm producers in tryptic soy broth + 1% glucose, 4 presented with the bap/fnbA/clfA/clfB/eno/fib/ebpS combination, and all were protected from cefquinome sulfate. We found no predominance of any agr group. The high invasive potential of S. aureus made it impossible to observe biofilm in bovine primary mammary epithelial cells, and we concluded that cells with lower invasion rates, such as HeLa cells, were more appropriate for this assay. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  10. Detection of toxic shock toxin (tst gene in Staphylococcus aureus isolated from bovine milk samples

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    S. Baniardalan

    2017-09-01

    Full Text Available Staphylococcus aureus is a major causative pathogen of clinical and subclinical mastitis in dairy cattle all over the world. This agent produces a variety of extracellular toxins and virulence factors in-cluding toxic shock syndrome toxin-1 (TSST-1 which is the major cause of toxic shock syndrome (TSS. In the present study, 76 S. aureus isolates have been obtained from milk samples collected from 7 dairy herds in Hamedan province of Iran. The isolates were identified based on the biochemical and molecular methods using PCR amplification of the femA gene. The staphylococcal isolates were also examined for the presence of TSST-1 (tst encoding gene. This gene was detected in only one S. aureus isolate (1.3%. The results revealed that S. aureus strains causing bovine mastitis may potentially produce staphylococcal toxic shock syndrome toxin-1, indicating that it is very important to follow the presence of TSST-1 producing S. aureus isolates in foodstuffs to protect consumers against the risk of toxic shock syndrome

  11. Use of phages against antibiotic-resistant Staphylococcus aureus isolated from bovine mastitis.

    Science.gov (United States)

    Dias, R S; Eller, M R; Duarte, V S; Pereira, Â L; Silva, C C; Mantovani, H C; Oliveira, L L; Silva, E de A M; De Paula, S O

    2013-08-01

    Bovine mastitis is the primary disease of dairy cattle worldwide and it causes large economic losses. Among several microorganisms that are the causative agents of this disease, Staphylococcus aureus is the most prevalent. Although antibiotic therapy is still the most widely used procedure for the treatment of bovine mastitis, alternative means of treatment are necessary due to the presence of antibiotic residues in milk, which is a growing concern because of its interference with the production of milk derivatives and the selection of resistant bacterial strains. The use of bacteriophages as a tool for the control of pathogens is an alternative treatment to antibiotic therapy. In this work, to obtain phages with the potential for use in phage therapy as a treatment for mastitis, we isolated and identified the bacteria from the milk of mastitis-positive cows. A total of 19% of the animals from small and medium farms of the Zona da Mata Mineira, Brazil, was positive for bovine mastitis, and bacteria of the genus Staphylococcus were the most prevalent pathogens. The majority of the S. aureus isolates tested was resistant to penicillin and ampicillin. In parallel, we isolated 10 bacteriophages able to infect some of these S. aureus isolates. We determined that these phages contained DNA genomes of approximately 175 kb in length, and the protein profiles indicated the presence of 4 major proteins. Electron microscopy revealed that the phages are caudate and belong to the Myoviridae family. The isolates exhibited interesting features for their use in phage therapy such as a high lytic potential, a wide range of hosts, and thermostability, all of which favor their use in the field.

  12. New method for early detection of two random amplified polymorphic DNA (RAPD groups of Staphylococcus aureus causing bovine mastitis infection in Paraná State, Brazil

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    Dicezar Gonçalves

    2010-04-01

    Full Text Available The aim of this work was to develop a fast and accurate molecular approach to allow early detection of two RAPD groups of S. aureus causing bovine mastitis. Seventy five S. aureus isolates from infected animals were characterized by RAPD. Genomic fragments isolated from the unique bands present in either group were cloned and sequenced. Based on the DNA sequences, specific primers were designed to allow for the simultaneous detection of either group by multiplex PCR of S. aureus DNA isolated from clinical and subclinical bovine mastitis. Results showed that these proposed primers set could be used to detect various clinical and subclinical S. aureus isolates as well as the detection of the microorganism in bulk milk. Their use as a specific method for effective and early diagnostic tool for S. aureus infection in dairy herds is suggested.Esta pesquisa objetivou o desenvolvimento de técnica rápida e eficiente para diagnosticar precocemente diferentes linhagens de S. aureus causadoras de mastite bovina. Como resultados da metodologia empregada, foram isoladas duas linhagens destas bactérias que causam diferentes tipos de mastite bovina. Os fragmentos de DNA genômico caracterizando ambas as linhagens, por meio de RAPD foram inseridos em vetor plasmidial pGEM e clonados por meio de clones T10 F1 de Escherichia coli. As seqüências obtidas permitiram desenhar iniciadores específicos para o reconhecimento de ambas as linhagens, os quais foram testados com amostras de S. aureus e com outras linhagens próximas. O diagnóstico por meios moleculares, pode ser realizado diretamente de amostras coletadas de rebanhos leiteiros assim como dos equipamentos de ordenha. A significância deste estudo consiste em um rápido e acurado método para localizar animais infectados, representando importante ferramenta no manejo do rebanho, na redução de custos com tratamentos e, rápida recuperação de rebanhos infectados.

  13. Phage types and antimicrobial resistance among Danish bovine Staphylococcus aureus isolates since the 1950s

    DEFF Research Database (Denmark)

    Vintov, Jan; Aarestrup, Frank Møller; Zinn, C. E.

    2003-01-01

    three time periods, representing 43.3% of the typeable isolates. This indicates that the Danish S. aureus population related to bovine mastitis has remained relatively unchanged over the last 50 years. The occurrence of antimicrobial resistance has remained low in Denmark in comparison to other......A total of 292 bovine Staphylococcus aureus isolates obtained from the 1950s (86 isolates), 1992 (107 isolates), and 2000 (99 isolates) were examined for antimicrobial susceptibility and phage typing. The same types of S. aureus (80, 52, 3A, 3A/3C, 42E, 77) were found among the isolates from all...

  14. Inhibition of Staphylococcus aureus invasion into bovine mammary epithelial cells by contact with live Lactobacillus casei.

    Science.gov (United States)

    Bouchard, Damien S; Rault, Lucie; Berkova, Nadia; Le Loir, Yves; Even, Sergine

    2013-02-01

    Staphylococcus aureus is a major pathogen that is responsible for mastitis in dairy herds. S. aureus mastitis is difficult to treat and prone to recurrence despite antibiotic treatment. The ability of S. aureus to invade bovine mammary epithelial cells (bMEC) is evoked to explain this chronicity. One sustainable alternative to treat or prevent mastitis is the use of lactic acid bacteria (LAB) as mammary probiotics. In this study, we tested the ability of Lactobacillus casei strains to prevent invasion of bMEC by two S. aureus bovine strains, RF122 and Newbould305, which reproducibly induce acute and moderate mastitis, respectively. L. casei strains affected adhesion and/or internalization of S. aureus in a strain-dependent manner. Interestingly, L. casei CIRM-BIA 667 reduced S. aureus Newbould305 and RF122 internalization by 60 to 80%, and this inhibition was confirmed for two other L. casei strains, including one isolated from bovine teat canal. The protective effect occurred without affecting bMEC morphology and viability. Once internalized, the fate of S. aureus was not affected by L. casei. It should be noted that L. casei was internalized at a low rate but survived in bMEC cells with a better efficiency than that of S. aureus RF122. Inhibition of S. aureus adhesion was maintained with heat-killed L. casei, whereas contact between live L. casei and S. aureus or bMEC was required to prevent S. aureus internalization. This first study of the antagonism of LAB toward S. aureus in a mammary context opens avenues for the development of novel control strategies against this major pathogen.

  15. Inhibition of Staphylococcus aureus Invasion into Bovine Mammary Epithelial Cells by Contact with Live Lactobacillus casei

    Science.gov (United States)

    Bouchard, Damien S.; Rault, Lucie; Berkova, Nadia; Le Loir, Yves

    2013-01-01

    Staphylococcus aureus is a major pathogen that is responsible for mastitis in dairy herds. S. aureus mastitis is difficult to treat and prone to recurrence despite antibiotic treatment. The ability of S. aureus to invade bovine mammary epithelial cells (bMEC) is evoked to explain this chronicity. One sustainable alternative to treat or prevent mastitis is the use of lactic acid bacteria (LAB) as mammary probiotics. In this study, we tested the ability of Lactobacillus casei strains to prevent invasion of bMEC by two S. aureus bovine strains, RF122 and Newbould305, which reproducibly induce acute and moderate mastitis, respectively. L. casei strains affected adhesion and/or internalization of S. aureus in a strain-dependent manner. Interestingly, L. casei CIRM-BIA 667 reduced S. aureus Newbould305 and RF122 internalization by 60 to 80%, and this inhibition was confirmed for two other L. casei strains, including one isolated from bovine teat canal. The protective effect occurred without affecting bMEC morphology and viability. Once internalized, the fate of S. aureus was not affected by L. casei. It should be noted that L. casei was internalized at a low rate but survived in bMEC cells with a better efficiency than that of S. aureus RF122. Inhibition of S. aureus adhesion was maintained with heat-killed L. casei, whereas contact between live L. casei and S. aureus or bMEC was required to prevent S. aureus internalization. This first study of the antagonism of LAB toward S. aureus in a mammary context opens avenues for the development of novel control strategies against this major pathogen. PMID:23183972

  16. Characterization of Staphylococcus aureus strains involved in human and bovine mastitis.

    Science.gov (United States)

    Delgado, Susana; García, Pilar; Fernández, Leonides; Jiménez, Esther; Rodríguez-Baños, Mercedes; del Campo, Rosa; Rodríguez, Juan M

    2011-07-01

    Staphylococcus aureus is one of the main etiological agents of mastitis in different mammalian species. At present, it is unknown whether strains isolated from human mastitis cases share phenotypic properties and genetic background with those obtained from animal mastitis cases. Therefore, the objective of this study was to characterize S. aureus strains isolated from women with lactational mastitis and to compare them with the strains responsible for bovine mastitis and noninfectious strains. All the strains were genotyped by both pulsed field gel electrophoresis and multilocus sequence typing and submitted to a characterization scheme that included diverse assays related to pathogenic potential and antibiotic resistance. Apart from siderophore production, no significant association was observed between the strains from bovine and human mastitis. Statistical differences between human- and bovine-mastitis-associated strains were detected for some traits and virulence determinants, such as the presence of prophages and cna and hlb genes, which were more frequently found within the bovine group. On the contrary, resistance to penicillin was significantly higher among strains isolated from human lactational mastitis, probably related to the common presence of the blaZ gene. A high genetic diversity was found among the strains involved in mastitis in breastfeeding women. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  17. LukM/LukF'-PV is the most active Staphylococcus aureus leukotoxin on bovine neutrophils.

    Science.gov (United States)

    Barrio, Maria B; Rainard, Pascal; Prévost, Gilles

    2006-07-01

    Staphylococcus aureus is a ubiquitous pathogen causing infections in humans and domestic animals. It is often associated with bovine mastitis. Among secreted virulence factors, the leukotoxins constitute a family of toxins composed of two distinct subunits (class S and F proteins) which induce first Ca2+ influx and subsequent pore formation that allows ethidium entry. As mastitis-causing isolates harbor the genes of at least two, and often three leukotoxins, we compared the biological activities of the purified leukotoxins whose genes are found in mastitis-causing isolates on bovine polymorphonuclear neutrophils (PMN): spreading on a solid support, calcium influx and ethidium entry. In the spreading assay, the homologous pair LukM/LukF'-PV was the most active leukotoxin. Within each class, either S or F, subunits were interchangeable and generated leukotoxins with different specific activity. LukM was also very active when associated with heterologous F subunits. A similar ranking of homologous pairs was also found in the ethidium entry assay: LukM/LukF'-PV > HlgA/HlgB > HlgC/HlgB > LukE/LukD = LukEv/LukDv. In the Ca2+ flux assay, LukM/F'-PV was the most active pair, but gamma-hemolysin (Hlg) was also very efficient. LukEv/Dv was more active (twofold) than LukE/D in the spreading assay, but the two variants showed similar activities in the other two assays. Supposing that spreading and ethidium entry (pore formation) reflect toxic activities on bovine PMN, and Ca2+ influx cell activation, LukM/F'-PV was by far the most cytotoxic leukotoxin, but it was closely followed by gamma-hemolysin for PMN activation. These results suggest that LukM/F'-PV may constitute a particular virulence attribute of mastitis-causing S. aureus strains.

  18. Extensive Genomic Diversity among Bovine-Adapted Staphylococcus aureus: Evidence for a Genomic Rearrangement within CC97.

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    Kathleen E Budd

    Full Text Available Staphylococcus aureus is an important pathogen associated with both human and veterinary disease and is a common cause of bovine mastitis. Genomic heterogeneity exists between S. aureus strains and has been implicated in the adaptation of specific strains to colonise particular mammalian hosts. Knowledge of the factors required for host specificity and virulence is important for understanding the pathogenesis and management of S. aureus mastitis. In this study, a panel of mastitis-associated S. aureus isolates (n = 126 was tested for resistance to antibiotics commonly used to treat mastitis. Over half of the isolates (52% demonstrated resistance to penicillin and ampicillin but all were susceptible to the other antibiotics tested. S. aureus isolates were further examined for their clonal diversity by Multi-Locus Sequence Typing (MLST. In total, 18 different sequence types (STs were identified and eBURST analysis demonstrated that the majority of isolates grouped into clonal complexes CC97, CC151 or sequence type (ST 136. Analysis of the role of recombination events in determining S. aureus population structure determined that ST diversification through nucleotide substitutions were more likely to be due to recombination compared to point mutation, with regions of the genome possibly acting as recombination hotspots. DNA microarray analysis revealed a large number of differences amongst S. aureus STs in their variable genome content, including genes associated with capsule and biofilm formation and adhesion factors. Finally, evidence for a genomic arrangement was observed within isolates from CC97 with the ST71-like subgroup showing evidence of an IS431 insertion element having replaced approximately 30 kb of DNA including the ica operon and histidine biosynthesis genes, resulting in histidine auxotrophy. This genomic rearrangement may be responsible for the diversification of ST71 into an emerging bovine adapted subgroup.

  19. Chimeric phage lysins act synergistically with lysostaphin to kill mastitis causing staphylococcus aureus in murine mammary glands

    Science.gov (United States)

    Staphylococci cause bovine mastitis with Staphylococcus aureus being responsible for the majority of the mastitis-based losses to the dairy industry (up to $2 billion/annum). Treatment is primarily with antibiotics that are often ineffective and potentially contribute to resistance development. Bac...

  20. Nisin and lysostaphin activity against preformed biofilm of Staphylococcus aureus involved in bovine mastitis.

    Science.gov (United States)

    Ceotto-Vigoder, H; Marques, S L S; Santos, I N S; Alves, M D B; Barrias, E S; Potter, A; Alviano, D S; Bastos, M C F

    2016-07-01

    The biofilm produced by Staphylococcus aureus isolates involved in clinical or subclinical bovine mastitis and the activity of nisin and lysostaphin against the preformed biofilm produced by these strains were investigated. Eighteen strains were tested and all produced biofilm. Eight strains with distinct biofilm composition were selected for the antimicrobial activity assays. The minimal inhibitory concentration of each bacteriocin was determined against the planktonic cells and ranged from 15·6 to 500 μg ml(-1) for nisin, and from 3·9 to 50 μg ml(-1) , for lysostaphin. Lysostaphin treatment (0·4 μg ml(-1) ) for 4 h caused a strong Staph. aureus 4181 biofilm detachment and death of the majority of the sessile cells, while nisin treatment (100 μg ml(-1) ) for the same time caused only a great reduction in cell viability. Additionally, combination of both bacteriocins for 4 h resulted in significant death of the sessile cells but no biofilm detachment. The treatment with lysostaphin alone or in combination with nisin was effective in killing most biofilm sessile cells. The action of lysostaphin, either alone or in combination with nisin, against established staphylococcal biofilm may represent an alternative to bovine mastitis control. However, the duration of the treatment should be considered for its application so that the best effectiveness can be achieved. © 2016 The Society for Applied Microbiology.

  1. Molecular characterization of antibiotic-resistant Staphylococcus aureus from livestock (bovine and swine

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    Asima Zehra

    2017-06-01

    Full Text Available Aim: The aim of this study was to figure the prevalence, phenotypic and genotypic antibiotic resistance (AR pattern of Staphylococcus aureus isolated from bovine and swine nares. Materials and Methods: Colonies with typical morphology on Baird-Parker agar supplemented with egg-yolk tellurite emulsion were selected and biochemically/genotypically identified as S. aureus. These strains were further subjected to epsilometer test for their sensitivity to various clinically important antibiotics and antibiotic susceptibility testing for amoxicillin/clavulanic acid, and double-disk diffusion testing was performed by the standard disc diffusion method following CLSI guidelines. S. aureus strains were also tested for the presence of AR genes, viz., blaZ, mecA, aacA-aphD, erm (ermA, ermB, ermC, tet (efflux genes tetK and tetL, tetM and tetO of the ribosomal protection family, and vanA. Results: The nasal cavities of 17 out of 47 randomly selected bovine and 20 out of 28 randomly selected swine were positive for S. aureus, representing the prevalence of 36.2% (95% confidence interval [CI]: 22.5-49.9 and 71.4% (95% CI: 54.7-88.1, respectively. Most of the S. aureus strains showed higher resistance to penicillin (94.6%, minimal inhibitory concentration [MIC] =1.5 μg/ml followed by ciprofloxacin (56.7%, MIC =32 μg/ml and tetracycline (18.9%, MIC =32 μg/ml. About 10-15% of the strains were resistant to gentamicin (MIC 16 μg/ml and oxacillin (MIC 6-8 μg/ml. None of the strains were resistant to vancomycin (MIC 0.25-1.5 μg/ml. In this study, 32.4% strains were resistant to three or more than three antibiotics and prevalence of this multi-drug resistant S. aureus was 45% (95% CI: 26.6-63.4 and 17.6% (95% CI: 6.7- 28.5 in swine and bovine nasal samples, respectively. Four strains from pigs were borderline oxacillin-resistant S. aureus MIC 6-8 μg/ml, but none were mecA positive. Two of these strains were β-lactamase hyperproducers. Among the resistance

  2. Screening of medicinal plants for antibacterial activities on Staphylococcus aureus strains isolated from bovine mastitis

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    Marisa A. N. Diaz

    2010-08-01

    Full Text Available Staphylococcus aureus is the main causative agent of bovine mastitis. The activity of several extracts from ten medicinal plants traditionally used in Brazil as antiseptic was investigated against fifteen strains of Staphylococcus aureus isolated from animals with mastitis manifestation by the disc diffusion method and broth microdilution assay. The interference of the extracts on cell in the form of adherent colonies was also evaluated. MIC values ranged from 0.5 mg/mL to 1.0 mg/mL and biofilm inhibitory concentration (BIC were between 0.25 mg/mL and 0.8 mg/mL. Results revealed the potential of extracts of Senna macranthera, Artemisia absinthium, Cymbopogon nardus and Baccharis dracunculifolia as antibacterial agents against S. aureus strains isolated from bovine mastitis and support the possible use of these phytotherapic agents in the clinical management of the disease.

  3. Investigation of Virulence Genes by PCR in Stapylococcus aureus Isolates Originated from Subclinical Bovine Mastitis in Turkey

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    Murat Karahan, Mehmet Nuri Acik1* and Burhan Cetinkaya

    2011-06-01

    Full Text Available The aim of the present study was to characterize coagulase (coa positive Staphylococcus aureus strains (n=92 isolated from bovine subclinical mastitis in Turkey by PCR amplification of clumping factor A (clfA and protein A (spa genes. All the coa-positive S. aureus isolates were determined to harbor the genes encoding the IgG binding region (spa-IgG and the X region (spa-X of spa. On the other hand, 84 (91.3% isolates were positive for clfA gene. These three genes displayed size polymorphisms. It was concluded that spa gene polymorphisms for S. aureus, when used together with coa-PCR, can be proposed as good alternatives to conventional methods in typing S. aureus isolates of bovine origin which may provide valuable data for the development of effective control strategies against staphylococcal mastitis. The results of the present study showed that S. aureus isolates responsible for the mastitis cases in Turkey were genetically diverse.

  4. High incidence of oxacillin-susceptible mecA-positive Staphylococcus aureus (OS-MRSA associated with bovine mastitis in China.

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    WanXia Pu

    Full Text Available Staphylococcus aureus is a main cause of bovine mastitis and a major pathogen affecting human health. The emergence and spread of methicillin-resistant Staphylococcus aureus (MRSA has become a significant concern for both animal health and public health. This study investigated the incidence of MRSA in milk samples collected from dairy cows with clinical mastitis and characterized the MRSA isolates using antimicrobial susceptibility tests and genetic typing methods. In total, 103 S. aureus isolates were obtained from dairy farms in 4 different provinces in China, including Gansu, Shanghai, Sichuan, and Guizhou. Antimicrobial susceptibility testing of these isolates revealed that the resistance rates to penicillin and sulfamethoxazole were high, while the resistance rates to ciprofloxacin and vancomycin were low. Among the 103 isolates, 49 (47.6% were found to be mecA-positive, indicating the high incidence of MRSA. However, 37 of the 49 mecA-positive isolates were susceptible to oxacillin as determined by antimicrobial susceptibility assays and were thus classified as oxacillin-susceptible mecA-positive S. aureus (OS-MRSA. These isolates could be misclassified as methicillin susceptible Staphylococcus aureus (MSSA if genetic detection of mecA was not performed. Molecular characterization of selected mecA-positive isolates showed that they were all negative with Panton-Valentine leukocidin (PVL, but belonged to different spa types and SCCmec types. These results indicate that OS-MRSA is common in bovine mastitis in China and underscore the need for genetic methods (in addition to phenotypic tests to accurately identify MRSA.

  5. Expression, immunogenicity and variation of iron-regulated surface protein A from bovine isolates of Staphylococcus aureus

    Science.gov (United States)

    Misra, Neha; Wines, Tyler F.; Knopp, Colton L.; McGuire, Mark A.; Tinker, Juliette K.

    2017-01-01

    Abstract Staphylococcus aureus iron-regulated surface protein A (IsdA) is a fibrinogen and fibronectin adhesin that also contributes to iron sequestration and resistance to innate immunity. IsdA is conserved in human isolates and has been investigated as a human vaccine candidate. Here we report the expression of isdA, the efficacy of anti-IsdA responses and the existence of IsdA sequence variants from bovine Staphylococcus. Clinical staphylococci were obtained from US dairy farms and assayed by PCR for the presence and expression of isdA. isdA-positive species from bovines included S. aureus, S. haemolyticus and S. chromogenes. Immunoassays on bovine milk and serum confirmed the induction and opsonophagocytic activity of anti-IsdA humoral responses. The variable region of isdA was sequenced and protein alignments predicted the presence of two main variants consistent with those from human S. aureus. Mouse antibodies against one IsdA variant reduced staphylococcal binding to fibronectin in vitro in an isotype-dependent manner. Purified IsdA variants bound distinctly to fibronectin and fibrinogen. Our findings demonstrate that variability within the C-terminus of this adhesin affects immune reactivity and binding specificity, but are consistent with the significance of IsdA in bovine disease and relevant for vaccine development. PMID:28430959

  6. Antibiofilm and antibacterial effects of specific chitosan molecules on Staphylococcus aureus isolates associated with bovine mastitis

    Science.gov (United States)

    Asli, Abdelhamid; Brouillette, Eric; Ster, Céline; Ghinet, Mariana Gabriela; Brzezinski, Ryszard; Lacasse, Pierre; Jacques, Mario

    2017-01-01

    Staphylococcus aureus is one of the major pathogens causing bovine intramammary infections (IMIs) and mastitis. Mastitis is the primary cause for the use of antibiotics in dairy farms but therapeutic failure is often observed. One of the reasons for the lack of effectiveness of antibiotic therapy despite the observed susceptibility of bacterial isolates in vitro are bacterial biofilms. In this study, we used chitosan of well-defined molecular weight (0.4–0.6, 1.3, 2.6 and 4.0 kDa) and investigated their antibiofilm and antibacterial activities in in vitro and in vivo models related to S. aureus IMIs. A chitosan of at least 6 units of glucosamine was necessary for maximum antibacterial activity. The 2.6 and 4.0 kDa forms were able to prevent biofilm production by the biofilm hyperproducer strain S. aureus 2117 and a bovine MRSA (methicillin-resistant S. aureus). The intramammary administration of the 2.6 kDa chitosan showed no adverse effects in mice or in cows, as opposed to the slight inflammatory effect observed in mammary glands with the 4.0 kDa derivative. The 2.6 kDa chitosan killed bacteria embedded in pre-established biofilms in a dose-dependent manner with a >3 log10 reduction in CFU at 4 mg/ml. Also, the 2.6 kDa chitosan could prevent the persistence of the internalized MRSA into the mammary epithelial cell line MAC-T. An in vitro checkerboard assay showed that the 2.6 kDa chitosan produced a synergy with the macrolide class of antibiotics (e.g., tilmicosin) and reduced the MIC of both molecules by 2–8 times. Finally, the intramammary administration of the 2.6 kDa chitosan alone (P<0.01) or in combination with tilmicosin (P<0.0001) reduced the colonization of mammary glands in a murine IMI model. Our results suggest that the use of chitosan alone or in combination with a low dose of a macrolide could help reduce antibiotic use in dairy farms. PMID:28486482

  7. Antibiofilm and antibacterial effects of specific chitosan molecules on Staphylococcus aureus isolates associated with bovine mastitis.

    Directory of Open Access Journals (Sweden)

    Abdelhamid Asli

    Full Text Available Staphylococcus aureus is one of the major pathogens causing bovine intramammary infections (IMIs and mastitis. Mastitis is the primary cause for the use of antibiotics in dairy farms but therapeutic failure is often observed. One of the reasons for the lack of effectiveness of antibiotic therapy despite the observed susceptibility of bacterial isolates in vitro are bacterial biofilms. In this study, we used chitosan of well-defined molecular weight (0.4-0.6, 1.3, 2.6 and 4.0 kDa and investigated their antibiofilm and antibacterial activities in in vitro and in vivo models related to S. aureus IMIs. A chitosan of at least 6 units of glucosamine was necessary for maximum antibacterial activity. The 2.6 and 4.0 kDa forms were able to prevent biofilm production by the biofilm hyperproducer strain S. aureus 2117 and a bovine MRSA (methicillin-resistant S. aureus. The intramammary administration of the 2.6 kDa chitosan showed no adverse effects in mice or in cows, as opposed to the slight inflammatory effect observed in mammary glands with the 4.0 kDa derivative. The 2.6 kDa chitosan killed bacteria embedded in pre-established biofilms in a dose-dependent manner with a >3 log10 reduction in CFU at 4 mg/ml. Also, the 2.6 kDa chitosan could prevent the persistence of the internalized MRSA into the mammary epithelial cell line MAC-T. An in vitro checkerboard assay showed that the 2.6 kDa chitosan produced a synergy with the macrolide class of antibiotics (e.g., tilmicosin and reduced the MIC of both molecules by 2-8 times. Finally, the intramammary administration of the 2.6 kDa chitosan alone (P<0.01 or in combination with tilmicosin (P<0.0001 reduced the colonization of mammary glands in a murine IMI model. Our results suggest that the use of chitosan alone or in combination with a low dose of a macrolide could help reduce antibiotic use in dairy farms.

  8. Determination of phagocytosis of 32P-labeled Staphylococcus aureus by bovine polymorphonuclear leukocytes

    International Nuclear Information System (INIS)

    Dulin, A.M.; Paape, M.J.; Weinland, B.T.

    1984-01-01

    A procedure for the measurement of phagocytosis by bovine polymorphonuclear leukocytes (PMN) of 32 P-labeled Staphylococcus aureus was modified so that a larger number of samples could be compared in a single run, and smaller volumes of sample, PMN, and 32 P-labeled S aureus could be used. Results were highly reproducible, with a coefficient of variation between duplicate determinations of less than or equal to 2%. Lysostaphin was prepared from the supernatant of S staphylolyticus and was compared with a commercially available preparation. Effects of lysostaphin on PMN and influence of incubation media on release of 32 P from 32 P-labeled S aureus by lysostaphin were examined

  9. Expression, immunogenicity and variation of iron-regulated surface protein A from bovine isolates of Staphylococcus aureus.

    Science.gov (United States)

    Misra, Neha; Wines, Tyler F; Knopp, Colton L; McGuire, Mark A; Tinker, Juliette K

    2017-05-01

    Staphylococcus aureus iron-regulated surface protein A (IsdA) is a fibrinogen and fibronectin adhesin that also contributes to iron sequestration and resistance to innate immunity. IsdA is conserved in human isolates and has been investigated as a human vaccine candidate. Here we report the expression of isdA, the efficacy of anti-IsdA responses and the existence of IsdA sequence variants from bovine Staphylococcus. Clinical staphylococci were obtained from US dairy farms and assayed by PCR for the presence and expression of isdA. isdA-positive species from bovines included S. aureus, S. haemolyticus and S. chromogenes. Immunoassays on bovine milk and serum confirmed the induction and opsonophagocytic activity of anti-IsdA humoral responses. The variable region of isdA was sequenced and protein alignments predicted the presence of two main variants consistent with those from human S. aureus. Mouse antibodies against one IsdA variant reduced staphylococcal binding to fibronectin in vitro in an isotype-dependent manner. Purified IsdA variants bound distinctly to fibronectin and fibrinogen. Our findings demonstrate that variability within the C-terminus of this adhesin affects immune reactivity and binding specificity, but are consistent with the significance of IsdA in bovine disease and relevant for vaccine development. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Antimicrobial potential of Eucalyptus globulus against biofilms of Staphylococcus aureus isolated from bovine mastitis

    OpenAIRE

    Gomes, F. I.; Martins, Natália; Ferreira, Isabel C. F. R.; Henriques, Mariana

    2016-01-01

    Staphylococcus aureus are among the most common species isolated from bovine mastitis. The pathogenesis of this bacterium is facilitated by a number of virulence factors, including the ability to adhere to abiotic surfaces and/or host tissues often leading to biofilms' formation. From the clinical perspective, the most important feature of Staphytococcus species' biofilms is their high tolerance to the conventional antimicrobial therapy. So, the increasing number of bovine m...

  11. Combined analysis of DNA methylome and transcriptome reveal novel candidate genes with susceptibility to bovine Staphylococcus aureus subclinical mastitis.

    Science.gov (United States)

    Song, Minyan; He, Yanghua; Zhou, Huangkai; Zhang, Yi; Li, Xizhi; Yu, Ying

    2016-07-14

    Subclinical mastitis is a widely spread disease of lactating cows. Its major pathogen is Staphylococcus aureus (S. aureus). In this study, we performed genome-wide integrative analysis of DNA methylation and transcriptional expression to identify candidate genes and pathways relevant to bovine S. aureus subclinical mastitis. The genome-scale DNA methylation profiles of peripheral blood lymphocytes in cows with S. aureus subclinical mastitis (SA group) and healthy controls (CK) were generated by methylated DNA immunoprecipitation combined with microarrays. We identified 1078 differentially methylated genes in SA cows compared with the controls. By integrating DNA methylation and transcriptome data, 58 differentially methylated genes were shared with differently expressed genes, in which 20.7% distinctly hypermethylated genes showed down-regulated expression in SA versus CK, whereas 14.3% dramatically hypomethylated genes showed up-regulated expression. Integrated pathway analysis suggested that these genes were related to inflammation, ErbB signalling pathway and mismatch repair. Further functional analysis revealed that three genes, NRG1, MST1 and NAT9, were strongly correlated with the progression of S. aureus subclinical mastitis and could be used as powerful biomarkers for the improvement of bovine mastitis resistance. Our studies lay the groundwork for epigenetic modification and mechanistic studies on susceptibility of bovine mastitis.

  12. Inhibition of Staphylococcus aureus Invasion into Bovine Mammary Epithelial Cells by Contact with Live Lactobacillus casei

    OpenAIRE

    Bouchard, Damien S.; Rault, Lucie; Berkova, Nadia; Le Loir, Yves; Even, Sergine

    2013-01-01

    Staphylococcus aureus is a major pathogen that is responsible for mastitis in dairy herds. S. aureus mastitis is difficult to treat and prone to recurrence despite antibiotic treatment. The ability of S. aureus to invade bovine mammary epithelial cells (bMEC) is evoked to explain this chronicity. One sustainable alternative to treat or prevent mastitis is the use of lactic acid bacteria (LAB) as mammary probiotics. In this study, we tested the ability of Lactobacillus casei strains to prevent...

  13. Application of Pulsed-Field Gel Electrophoresis and Binary Typing as Tools in Veterinary Clinical Microbiology and Molecular Epidemiologic Analysis of Bovine and Human Staphylococcus aureus Isolates

    Science.gov (United States)

    Zadoks, Ruth; van Leeuwen, Willem; Barkema, Herman; Sampimon, Otlis; Verbrugh, Henri; Schukken, Ynte Hein; van Belkum, Alex

    2000-01-01

    Thirty-eight bovine mammary Staphylococcus aureus isolates from diverse clinical, temporal, and geographical origins were genotyped by pulsed-field gel electrophoresis (PFGE) after SmaI digestion of prokaryotic DNA and by means of binary typing using 15 strain-specific DNA probes. Seven pulsed-field types and four subtypes were identified, as were 16 binary types. Concordant delineation of genetic relatedness was documented by both techniques, yet based on practical and epidemiological considerations, binary typing was the preferable method. Genotypes of bovine isolates were compared to 55 previously characterized human S. aureus isolates through cluster analysis of binary types. Genetic clusters containing strains of both human and bovine origin were found, but bacterial genotypes were predominantly associated with a single host species. Binary typing proved an excellent tool for comparison of S. aureus strains, including methicillin-resistant S. aureus, derived from different host species and from different databases. For 28 bovine S. aureus isolates, detailed clinical observations in vivo were compared to strain typing results in vitro. Associations were found between distinct genotypes and severity of disease, suggesting strain-specific bacterial virulence. Circumstantial evidence furthermore supports strain-specific routes of bacterial dissemination. We conclude that PFGE and binary typing can be successfully applied for genetic analysis of S. aureus isolates from bovine mammary secretions. Binary typing in particular is a robust and simple method and promises to become a powerful tool for strain characterization, for resolution of clonal relationships of bacteria within and between host species, and for identification of sources and transmission routes of bovine S. aureus. PMID:10790124

  14. Molecular Typing and Antimicrobial Susceptibility of Methicillin-Resistant Staphylococcus aureus Isolated from Bovine Milk in Tanzania.

    Science.gov (United States)

    Mohammed, Jibril; Ziwa, Michael Henry; Hounmanou, Yaovi Mahuton Gildas; Kisanga, Adela; Tuntufye, Huruma Nelwike

    2018-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) in raw milk can be transmitted from animals to humans, and in Tanzania raw milk is sold in local markets and consumed as purchased. This study was performed to determine the molecular characteristics and antimicrobial susceptibility pattern of MRSA strains isolated from raw bovine milk sold at local markets in Tanzania. A total of 117 raw milk samples were cultured on Baird-Parker medium to isolate S. aureus and PCR was used for amplification of gltB gene for S. aureus identification and the presence of mecA gene for methicillin-resistant strains. Coagulase-negative (CN) S. aureus were reconfirmed using tube coagulase, DNase, and API Staph tests. MRSA isolates were spa typed whereas antimicrobial susceptibility testing was performed by the disc diffusion method. Forty-six coagulase positives (CP) and two CN S. aureus were identified. Most strains were resistant to penicillin (72%), and 3 isolates: 2 CN S. aureus and 1 coagulase-negative Staphylococci (CNS), were phenotypically resistant to vancomycin, oxacillin, and cefoxitin and were confirmed to carry mecA. Resistance to clindamycin, trimethoprim-sulfamethoxazole, and tetracycline was 23.9%, 30.4%, and 41.3%, respectively. Twelve isolates exhibited multidrug resistance; however, only one mecA positive strain among the three was typeable and belonged to spa type t2603. This study reports for the first time the presence of CN variant of MRSA, which was assigned the spa type t2603, and the presence of multidrug resistant S. aureus isolates from bovine milk in Morogoro, Tanzania.

  15. Detection of some virulence factors in Staphylococcus aureus ...

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... Mastitis is one of the common diseases of dairy cattle and an inflammatory ... Key words: Bovine mastitis, Staphylococcus aureus, virulence factors, ... frequent cause of subclinical intramammary infections in ... genotypes has not been investigated. ... genes in S. aureus, we were particularly interested in the.

  16. Antimicrobial susceptibility of Staphylococcus aureus isolated from bovine mastitis in Europe and the United States

    DEFF Research Database (Denmark)

    De Oliveira, A. P.; Watts, J. L.; Salmon, S. A.

    2000-01-01

    Minimum inhibitory concentrations were determined for 811 strains of Staphylococcus aureus isolated from cases of bovine mastitis in 11 countries. The countries and number of isolates included Denmark (105), England (92), Finland (95), Germany (103), Iceland (22), Ireland (42), Norway (101), Sweden...... antimicrobial agents tested regardless of country. Given the differences in antimicrobial use in various countries, the widespread adoption of mastitis control programs to prevent infections limits the exposure of S. aureus infected animals to antimicrobial drugs....

  17. Evaluation of antibacterial activity of nitric oxide-releasing polymeric particles against Staphylococcus aureus and Escherichia coli from bovine mastitis.

    Science.gov (United States)

    Cardozo, Viviane F; Lancheros, Cesar A C; Narciso, Adélia M; Valereto, Elaine C S; Kobayashi, Renata K T; Seabra, Amedea B; Nakazato, Gerson

    2014-10-01

    Bovine mastitis is a serious veterinary disease that causes great loss to the dairy industry worldwide. It is a major infectious disease and is difficult to manage and control. Furthermore, emerging multidrug resistant bacteria that cause mastitis have complicated such management. The free radical nitric oxide (NO) is a potent antimicrobial agent. Thus, the aims of this study were to prepare and evaluate the antibacterial activity of nitric oxide-releasing polymeric particles against Staphylococcus aureus (MBSA) and Escherichia coli (MBEC), which were isolated from bovine mastitis. Fifteen MBSA isolates and fifteen MBEC were collected from subclinical and clinical bovine mastitis. Biocompatible polymeric particles composed of alginate/chitosan or chitosan/sodium tripolyphosphate (TPP) were prepared and used to encapsulate mercaptosuccinic acid (MSA), which is a thiol-containing molecule. Nitrosation of thiol groups of MSA-containing particles formed S-nitroso-MSA particles, which are NO donors. The NO release kinetics from the S-nitroso-MSA particles showed sustained and controlled NO release over several hours. The antibacterial activity of NO-releasing particles was evaluated by incubating the particles with an MBSA multi-resistant strain, which is responsible for bovine mastitis. The minimum inhibitory concentration for S-nitroso-MSA-alginate/chitosan particles against MBSA ranged from 125 μg/mL to 250 μg/mL. The results indicate that NO-releasing polymeric particles are an interesting approach to combating bacteria resistance in bovine mastitis treatment and prevention. Copyright © 2014. Published by Elsevier B.V.

  18. Effects of vitamin D and its metabolites on cell viability and Staphylococcus aureus invasion in bovine mammary epithelial cells

    DEFF Research Database (Denmark)

    Yue, Yuan; Hymøller, Lone; Jensen, Søren Krogh

    2017-01-01

    Vitamin D has been found have various biological effects that may be potent in preventing bovine mastitis. Two forms of vitamin D, vitamin D2 (D2) and vitamin D3 (D3), can be hydroxylated to functional metabolites in cattle. The objectives of the present study were to investigate the effects of D2...... and D3 compounds on bovine mammary epithelial cell proliferation and Staphylococcus aureus (S. aureus) invasion.. Results showed that 1,25-dihydroxyvitamin D2 have an anti-proliferation activity comparable to 1,25-dihydroxyvitamin D3, while D2 and 25-hydroxyvitamin D2 (25(OH)D2) was slightly more potent...

  19. Performance of culture media for the isolation and identification of Staphylococcus aureus from bovine mastitis.

    Science.gov (United States)

    Bautista-Trujillo, G U; Solorio-Rivera, J L; Rentería-Solórzano, I; Carranza-Germán, S I; Bustos-Martínez, J A; Arteaga-Garibay, R I; Baizabal-Aguirre, V M; Cajero-Juárez, M; Bravo-Patiño, A; Valdez-Alarcón, J J

    2013-03-01

    Rapid isolation and identification of pathogens is a major goal of diagnostic microbiology. In order to isolate and identify Staphylococcus aureus, a number of authors have used a variety of selective and/or differential culture media. However, to date, there are no reports comparing the efficacy of selective and differential culture media for S. aureus isolation from bovine mastitis cases using the 16S rRNA (rrs) gene sequence as a gold standard test. In the present study, we evaluated the efficacy of four selective and/or differential culture media for the isolation of S. aureus from milk samples collected from cows suffering from bovine mastitis. Four hundred and forty isolates were obtained using salt-mannitol agar (SMA, Bioxon), Staphylococcus-110 agar (S110, Bioxon), CHROMAgar Staph aureus (CSA, BD-BBL) and sheep's blood agar (SBA, BD-BBL). All bacterial isolates were identified by their typical colony morphology in the respective media, by secondary tests (for coagulase and β-haemolysis) and by partial 16S rRNA (rrs) gene sequencing as a gold standard test. Sensitivity, positive predictive and negative predictive values were higher for SMA (86.96, 52.63 and 95.95%, respectively) compared with S110 (70.00, 23.73 and 90.91%, respectively), CSA (69.23, 28.13 and 95.74%, respectively) and SBA (68.75, 37.93 and 89.58%, respectively) while specificity values were similar for all media. Data indicated that the use of culture media for S. aureus isolation combined with determination of coagulase activity and haemolysis as secondary tests improved accuracy of the identification and was in accordance with rrs gene sequence-analysis compared with the use of the culture media alone.

  20. COUNTS OF MICROORGANISMS CAUSING BOVINE MASTITIS AND STUDY OF ANTIMICROBIAL ACTION

    Directory of Open Access Journals (Sweden)

    Wanessa Oliveira Ribeiro

    2014-02-01

    Full Text Available Mastitis is an inflammation of the mammary gland caused mainly by microorganisms, altering the characteristics of milk and results in significant economic losses for this production complex. The study aimed to determine the main causative agents of bovine mastitis in a dairy farm in Rio Pomba city, Minas Gerais state, Brazil, and evaluate the use of plant extract and antibiotics commonly used in the control of microorganisms that cause this disease. Raw milk samples coming from 47 dairy cow were individually collected for microbiological evaluation. We also evaluated the sensitivity of isolates from the plant extract and the antibiotics commonly used in the farm. It was found that 17.0 %, 31.9 %, 85.4 % and 38.3 % of the samples presented, respectively, Staphylococcus aureus, coliforms, faecal coliforms and Escherichia coli. Furthermore, most of the samples showed counts of aerobic mesophilic microorganisms and Streptococcus sp. between 104 and 105 CFU.mL-1, while the counts of S. aureus ranged between 102 and 103 CFU.mL-1 in most of samples. A higher efficacy of tetracycline on the isolates of S. aureus was verified and of ampicillin on the E. coli isolates. All isolates of the latter bacteria were resistant to plant extract. Due to the high incidence of microorganisms, we emphasize the need for implementation of Good Agricultural Practices in milk production, because these bacteria are coming from hair, skin, mucous membranes of animals and/or belonging to the enteric microbiota of mammals, respectively.

  1. Geographical variation in the presence of genes encoding superantigenic exotoxins and beta-hemolysin among Staphylococcus aureus isolated from bovine mastitis in Europe and USA

    DEFF Research Database (Denmark)

    Larsen, H. D.; Aarestrup, Frank Møller; Jensen, N. E.

    2002-01-01

    The object was to examine the geographical variation in the presence of superantigenic exotoxins and beta-hemolysin among epidemiologically independent Staphyirrcoccus aureus isolates from bovine mastitis. A total of 462 S. aureus isolates from nine European countries and USA were examined...... for the individual exotoxins. The genes encoding enterotoxin C, TSST-1, and enterotoxin D were the most common superantigens. The present and earlier studies demonstrate that the superantigenic exotoxins that were investigated in this study, do not play a role in the pathogenesis of bovine S. aureus mastitis...... regions in the beta-hemolysin encoding gene of the Norwegian isolates is suggested, and should be investigated further. The consistent presence of beta-hemolysin suggests that this factor, or a co-existing gene correlated to beta-hemolysin, may be an active virulence factor in the pathogenesis of bovine S...

  2. Comparison of Staphylococcus aureus genotypes recovered from cases of bovine, ovine, and caprine mastitis.

    Science.gov (United States)

    Mørk, T; Tollersrud, T; Kvitle, B; Jørgensen, H J; Waage, S

    2005-08-01

    Staphylococcus aureus is an important pathogen in domestic ruminants. The main objective of this study was to determine the similarity of epidemiologically unrelated S. aureus isolates from bovine, ovine, and caprine mastitis. By pulsed-field gel electrophoresis, 160 different pulsotypes (PTs) were identified among 905 isolates recovered from 588 herds in 12 counties in Norway. Based on estimates of similarity, using an 80% cluster cutoff, the isolates were assigned to 47 clusters. One cluster included 62% of all the isolates and more than 45% of the isolates from each host species. Twenty-three PTs included isolates from more than one host species; these 23 PTs represented 72% of all the isolates. The six most prevalent PTs included isolates from all host species and contained 45% of the bovine isolates, 54% of the ovine isolates, and 37% of the caprine isolates. Antimicrobial susceptibility testing of 373 of the isolates revealed resistance to penicillin in 2.9% and to streptomycin in 2.4%; only 1.9% were resistant to 1 of the other 11 antimicrobials tested. The results of this study suggest that a small number of closely related genotypes are responsible for a great proportion of S. aureus mastitis cases in cows, ewes, and goats in Norway and that these genotypes exhibit little or no host preference among these species. Selection due to antimicrobial resistance appears not to have contributed to the predominance of these genotypes.

  3. Evaluation of phenotypic and genotypic methods for epidemiological typing of Staphylococcus aureus isolates from bovine mastitis in Denmark

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Wegener, H. C.; Rosdahl, V. T.

    1995-01-01

    The value of five different typing methods (antibiogram typing, biotyping, phage typing, plasmid profiling and restriction fragment length polymorphism of the gene encoding 16S and 23S ribosomal RNA (ribotyping)), in discriminating 105 Staphylococcus aureus strains from bovine milk samples obtained....... The combination of phage, bio- or ribotyping or all three methods in combination are considered to be an efficient combination of typing methods for epidemiological investigation of S. aureus mastitis....

  4. Detection of the enterotoxigenic genes (sei,sej) in Staphylococcus aureus isolates from bovine mastitis milk in the West Azerbaijan of Iran.

    Science.gov (United States)

    Ahmady, Malahat; Kazemi, Sahar

    2013-07-01

    Staphylococcus aureus is a major causative pathogen of clinical and subclinical mastitis of dairy domestic ruminants. This organism produces a variety of extracellular toxins and virulence factors such as enterotoxin SEI and SEJ that contribute to its pathogenic potential. In this study 25 S. aureus isolates obtained from four dairy herds of Urmia region which is located in West Azerbaijan province in Iran. The tested isolates were identified on the basis of the cultural and biochemical properties, as well as amplification of the aroA gene which is specific for S. aureus . All isolates were also analyzed for the presence of the SEI ( sei ) and SEJ ( sej ) encoding genes using polymerase chain reaction (PCR). Seven positive isolates were detected for sei , but sej gene was not detected in any of the total number of 25 isolates. The present study revealed that the PCR amplification of the aroA gene could be used as a powerful tool for identification of S. aureus from the cases of bovine mastitis. Results of the present study also showed that the strains of S. aureus which cause mastitis can potentially produce enterotoxin SEI. Overall, our results suggest that it is of special importance to follow the presence of enterotoxin-producing S. aureus in other dairy products, especially for protecting the consumers from staphylococcal food poisoning.

  5. Identification of single nucleotide polymorphisms associated with hyperproduction of alpha-toxin in Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Xudong Liang

    2011-04-01

    Full Text Available The virulence factor α-toxin (hla is needed by Staphylococcus aureus in order to cause infections in both animals and humans. Although the complicated regulation of hla expression has been well studied in human S. aureus isolates, the mechanisms of of hla regulation in bovine S. aureus isolates remain undefined. In this study, we found that many bovine S. aureus isolates, including the RF122 strain, generate dramatic amounts of α-toxin in vitro compared with human clinical S. aureus isolates, including MRSA WCUH29 and MRSA USA300. To elucidate potential regulatory mechanisms, we analyzed the hla promoter regions and identified predominant single nucleotide polymorphisms (SNPs at positions -376, -483, and -484 from the start codon in α-toxin hyper-producing isolates. Using site-directed mutagenesis and hla promoter-gfp-luxABCDE dual reporter approaches, we demonstrated that the SNPs contribute to the differential control of hla expression among bovine and human S. aureus isolates. Using a DNA affinity assay, gel-shift assays and a null mutant, we identified and revealed that an hla positive regulator, SarZ, contributes to the involvement of the SNPs in mediating hla expression. In addition, we found that the bovine S. aureus isolate RF122 exhibits higher transcription levels of hla positive regulators, including agrA, saeR, arlR and sarZ, but a lower expression level of hla repressor rot compared to the human S. aureus isolate WCUH29. Our results indicate α-toxin hyperproduction in bovine S. aureus is a multifactorial process, influenced at both the genomic and transcriptional levels. Moreover, the identification of predominant SNPs in the hla promoter region may provide a novel method for genotyping the S. aureus isolates.

  6. [Aspects of the innate immune response to intramammary Staphylococcus aureus infections in cattle].

    Science.gov (United States)

    Pereyra, Elizabet A L; Dallard, Bibiana E; Calvinho, Luis F

    2014-01-01

    Staphylococcus aureus is the pathogen most frequently isolated from bovine mastitis worldwide, causing chronic intramammary infections that limit profitable dairying. The objective of this article is to characterize the mechanisms involved in S. aureus mammary gland infections considering two different aspects of the infectious process; on the one hand, the aspects involved in the host innate immune response and on the other hand, the capacity of this organism to evade the immune system and interact with different cell types. The exploration of S. aureus interactions with the immune response of bovine mammary gland will help identify targets to outline new preventive or curative alternatives for intramammary infections caused by this organism. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España. All rights reserved.

  7. Population structure and antimicrobial profile of Staphylococcus aureus strains associated with bovine mastitis in China.

    Science.gov (United States)

    Zhang, Lili; Li, Yuchen; Bao, Hongduo; Wei, Ruicheng; Zhou, Yan; Zhang, Hui; Wang, Ran

    2016-08-01

    Staphylococcus aureus is a significant bacterial pathogen associated with bovine mastitis. The aim of the present study was to investigate and characterize of S. aureus strains isolated from the milk of cows suffering from mastitis in the mid-east of China. Among the 200 milk samples analyzed, 58 were positive for S. aureus, of these isolates, 11 isolates were methicillin-resistant Staphylococcus aureus (MRSA). All of the 58 S. aureus strains were classified in agr group I, while seven different sequence type (ST) patterns were identified and among them the most common was ST630 followed by ST188. All of the S. aureus isolates belonging to ST630 were resistant to more than four antimicrobials, and 22.2% of isolates belonging to ST188 were resistant to eight antimicrobials. Interestingly, while strong biofilm producers demonstrated higher resistance to multiple antimicrobials, they exhibited lower intracellular survival rates. The results of this study illustrated the distribution, antimicrobial susceptibility profiles, genotype, and the ability of biofilm production and mammary epithelial cells invasion of these S. aureus isolates. This study can provide the basis for the development of a disease prevention program in dairy farms to reduce the potential risk in both animal and human health. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. A comparative study of Staphylococcus aureus strains isolated from bovine subclinical mastitis during 1952-1956 and 1992

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Wegener, Henrik Caspar; Rosdahl, V.T.

    1995-01-01

    Fiftytwo strains of S. aureus isolated from cases of bovine subclinical mastitis in 52 different dairy herds in Denmark, in the peri ods 1952 to 1956 and 1992, were compared with regard to their phage- and EcoRI ribotypes. Furthermore, susceptibility to penicillin and production of fibrinolysin...

  9. Characterization of Dutch Staphylococcus aureus from bovine mastitis using a Multiple Locus Variable Number Tandem Repeat Analysis

    NARCIS (Netherlands)

    Ikawaty, R.; Brouwer, E.C.; Jansen, M.D.; Duijkeren, van E.; Mevius, D.J.; Verhoef, J.; Fluit, A.C.

    2009-01-01

    Current typing methods for Staphylococcus aureus have important drawbacks. We evaluated a Multiple Locus Variable Number Tandem Repeat Analysis (MLVA) scheme with 6 loci which lacks most drawbacks on 85 bovine mastitis isolates from The Netherlands. For each locus the number of repeat units (RU) was

  10. Comprehensive Phylogenetic Analysis of Bovine Non-aureus Staphylococci Species Based on Whole-Genome Sequencing

    Science.gov (United States)

    Naushad, Sohail; Barkema, Herman W.; Luby, Christopher; Condas, Larissa A. Z.; Nobrega, Diego B.; Carson, Domonique A.; De Buck, Jeroen

    2016-01-01

    Non-aureus staphylococci (NAS), a heterogeneous group of a large number of species and subspecies, are the most frequently isolated pathogens from intramammary infections in dairy cattle. Phylogenetic relationships among bovine NAS species are controversial and have mostly been determined based on single-gene trees. Herein, we analyzed phylogeny of bovine NAS species using whole-genome sequencing (WGS) of 441 distinct isolates. In addition, evolutionary relationships among bovine NAS were estimated from multilocus data of 16S rRNA, hsp60, rpoB, sodA, and tuf genes and sequences from these and numerous other single genes/proteins. All phylogenies were created with FastTree, Maximum-Likelihood, Maximum-Parsimony, and Neighbor-Joining methods. Regardless of methodology, WGS-trees clearly separated bovine NAS species into five monophyletic coherent clades. Furthermore, there were consistent interspecies relationships within clades in all WGS phylogenetic reconstructions. Except for the Maximum-Parsimony tree, multilocus data analysis similarly produced five clades. There were large variations in determining clades and interspecies relationships in single gene/protein trees, under different methods of tree constructions, highlighting limitations of using single genes for determining bovine NAS phylogeny. However, based on WGS data, we established a robust phylogeny of bovine NAS species, unaffected by method or model of evolutionary reconstructions. Therefore, it is now possible to determine associations between phylogeny and many biological traits, such as virulence, antimicrobial resistance, environmental niche, geographical distribution, and host specificity. PMID:28066335

  11. Investigation of the antibiotic resistance and biofilm-forming ability of Staphylococcus aureus from subclinical bovine mastitis cases.

    Science.gov (United States)

    Aslantaş, Özkan; Demir, Cemil

    2016-11-01

    A total of 112 Staphylococcus aureus isolates obtained from subclinical bovine mastitis cases were examined for antibiotic susceptibility and biofilm-forming ability as well as genes responsible for antibiotic resistance, biofilm-forming ability, and adhesin. Antimicrobial susceptibility of the isolates were determined by disk diffusion method. Biofilm forming ability of the isolates were investigated by Congo red agar method, standard tube method, and microplate method. The genes responsible for antibiotic resistance, biofilm-forming ability, and adhesion were examined by PCR. Five isolates (4.5%) were identified as methicillin-resistant Staph. aureus by antibiotic susceptibility testing and confirmed by mecA detection. The resistance rates to penicillin, ampicillin, tetracycline, erythromycin, trimethoprim-sulfamethoxazole, enrofloxacin, and amoxicillin-clavulanic acid were 45.5, 39.3, 33, 26.8, 5.4, 0.9, and 0.9%, respectively. All isolates were susceptible against vancomycin and gentamicin. The blaZ (100%), tetK (67.6%), and ermA (70%) genes were the most common antibiotic-resistance genes. Using Congo red agar, microplate, and standard tube methods, 70.5, 67, and 62.5% of the isolates were found to be biofilm producers, respectively. The percentage rate of icaA, icaD, and bap genes in Staph. aureus isolates were 86.6, 86.6, and 13.4%, respectively. The adhesion molecules fnbA, can, and clfA were detected in 87 (77.7%), 98 (87.5%), and 75 (70%) isolates, respectively. The results indicated that Staph. aureus from sublinical bovine mastitis cases were mainly resistant to β-lactams and, to a lesser extent, to tetracycline and erythromycin. Also, biofilm- and adhesion-related genes, which are increasingly accepted as an important virulence factor in the pathogenesis of Staph. aureus infections, were detected at a high rate. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. Efficacy and Safety of a Bovine-Associated Staphylococcus aureus Phage Cocktail in a Murine Model of Mastitis

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    Koen Breyne

    2017-11-01

    Full Text Available Overuse of antibiotics is a major problem in the treatment of bovine mastitis, and antibiotic treatment is frequently non-curative, thus alternative treatments are necessary. The primary aim of this study was to evaluate the efficacy of a purified phage cocktail for treatment of bovine Staphylococcus aureus mastitis in a well-defined mouse model. Candidate phages were selected based on their in vitro performance and subsequently processed into an optimally composed phage cocktail. The highest scoring phages were further tested for efficacy and resistance suppression in broth and raw milk, with and without supplemental IgG. As these in vitro results displayed significant decreases in CFU, the cocktail was purified for testing in vivo. Lactating mice were intramammarily inoculated with S. aureus N305 (ATCC 29740, a clinical bovine mastitis isolate commonly used for experimental infection of dairy cows. The phage cocktail was applied via the same route 4 h post-inoculation. Treated mammary glands were graded for gross pathological appearance and excised for bacterial and phage load quantification as well as histopathology. Observation of gross macroscopic and histopathological changes and CFU quantification demonstrated that the phage cocktail treatment significantly improved mastitis pathology and decreased bacterial counts. Phage PFU quantification indicated that the tested phage cocktail treatment was able to maintain high intramammary phage titers without spreading systemically. The in vivo results complement the in vitro data and support our concept of phage therapy as an innovative alternative or supplementation therapy to antibiotics for the treatment of bovine mastitis.

  13. Efficacy and Safety of a Bovine-Associated Staphylococcus aureus Phage Cocktail in a Murine Model of Mastitis.

    Science.gov (United States)

    Breyne, Koen; Honaker, Ryan W; Hobbs, Zachary; Richter, Manuela; Żaczek, Maciej; Spangler, Taylor; Steenbrugge, Jonas; Lu, Rebecca; Kinkhabwala, Anika; Marchon, Bruno; Meyer, Evelyne; Mokres, Lucia

    2017-01-01

    Overuse of antibiotics is a major problem in the treatment of bovine mastitis, and antibiotic treatment is frequently non-curative, thus alternative treatments are necessary. The primary aim of this study was to evaluate the efficacy of a purified phage cocktail for treatment of bovine Staphylococcus aureus mastitis in a well-defined mouse model. Candidate phages were selected based on their in vitro performance and subsequently processed into an optimally composed phage cocktail. The highest scoring phages were further tested for efficacy and resistance suppression in broth and raw milk, with and without supplemental IgG. As these in vitro results displayed significant decreases in CFU, the cocktail was purified for testing in vivo . Lactating mice were intramammarily inoculated with S. aureus N305 (ATCC 29740), a clinical bovine mastitis isolate commonly used for experimental infection of dairy cows. The phage cocktail was applied via the same route 4 h post-inoculation. Treated mammary glands were graded for gross pathological appearance and excised for bacterial and phage load quantification as well as histopathology. Observation of gross macroscopic and histopathological changes and CFU quantification demonstrated that the phage cocktail treatment significantly improved mastitis pathology and decreased bacterial counts. Phage PFU quantification indicated that the tested phage cocktail treatment was able to maintain high intramammary phage titers without spreading systemically. The in vivo results complement the in vitro data and support our concept of phage therapy as an innovative alternative or supplementation therapy to antibiotics for the treatment of bovine mastitis.

  14. Meticillin-resistant Staphylococcus aureus with a novel mecA homologue in human and bovine populations in the UK and Denmark: a descriptive study.

    Science.gov (United States)

    García-Álvarez, Laura; Holden, Matthew T G; Lindsay, Heather; Webb, Cerian R; Brown, Derek F J; Curran, Martin D; Walpole, Enid; Brooks, Karen; Pickard, Derek J; Teale, Christopher; Parkhill, Julian; Bentley, Stephen D; Edwards, Giles F; Girvan, E Kirsty; Kearns, Angela M; Pichon, Bruno; Hill, Robert L R; Larsen, Anders Rhod; Skov, Robert L; Peacock, Sharon J; Maskell, Duncan J; Holmes, Mark A

    2011-08-01

    Animals can act as a reservoir and source for the emergence of novel meticillin-resistant Staphylococcus aureus (MRSA) clones in human beings. Here, we report the discovery of a strain of S aureus (LGA251) isolated from bulk milk that was phenotypically resistant to meticillin but tested negative for the mecA gene and a preliminary investigation of the extent to which such strains are present in bovine and human populations. Isolates of bovine MRSA were obtained from the Veterinary Laboratories Agency in the UK, and isolates of human MRSA were obtained from diagnostic or reference laboratories (two in the UK and one in Denmark). From these collections, we searched for mecA PCR-negative bovine and human S aureus isolates showing phenotypic meticillin resistance. We used whole-genome sequencing to establish the genetic basis for the observed antibiotic resistance. A divergent mecA homologue (mecA(LGA251)) was discovered in the LGA251 genome located in a novel staphylococcal cassette chromosome mec element, designated type-XI SCCmec. The mecA(LGA251) was 70% identical to S aureus mecA homologues and was initially detected in 15 S aureus isolates from dairy cattle in England. These isolates were from three different multilocus sequence type lineages (CC130, CC705, and ST425); spa type t843 (associated with CC130) was identified in 60% of bovine isolates. When human mecA-negative MRSA isolates were tested, the mecA(LGA251) homologue was identified in 12 of 16 isolates from Scotland, 15 of 26 from England, and 24 of 32 from Denmark. As in cows, t843 was the most common spa type detected in human beings. Although routine culture and antimicrobial susceptibility testing will identify S aureus isolates with this novel mecA homologue as meticillin resistant, present confirmatory methods will not identify them as MRSA. New diagnostic guidelines for the detection of MRSA should consider the inclusion of tests for mecA(LGA251). Department for Environment, Food and Rural Affairs

  15. Evaluation of a culture-based pathogen identification kit for bacterial causes of bovine mastitis.

    Science.gov (United States)

    Viora, L; Graham, E M; Mellor, D J; Reynolds, K; Simoes, P B A; Geraghty, T E

    2014-07-26

    Accurate identification of mastitis-causing bacteria supports effective management and can be used to implement selective use of antimicrobials for treatment. The objectives of this study were to compare the results from a culture-based mastitis pathogen detection test kit ('VetoRapid', Vétoquinol) with standard laboratory culture and to evaluate the potential suitability of the test kit to inform a selective treatment programme. Overall 231 quarter milk samples from five UK dairy farms were collected. The sensitivity and specificity of the test kit for the identification of Escherichia coli, Staphylococcus aureus, coagulase-negative staphylococci, Streptococcus uberis and Enterococcus spp. ranged from 17 per cent to 84 per cent and 92 per cent to 98 per cent, respectively. In total, 23 of 68 clinical samples were assigned as meeting the requirement for antimicrobial treatment (Gram-positive organism cultured) according to standard culture results, with the test kit results having sensitivity and specificity of 91 per cent and 78 per cent, respectively. Several occurrences of misidentification are reported, including S. aureus being misidentified as coagulase-negative staphylococci and vice versa. The test kit provides rapid preliminary identification of five common causes of bovine mastitis under UK field conditions and is likely to be suitable for informing selective treatment of clinical mastitis caused by Gram-positive organisms. British Veterinary Association.

  16. Extended biofilm susceptibility assay for Staphylococcus aureus bovine mastitis isolates: evidence for association between genetic makeup and biofilm susceptibility.

    Science.gov (United States)

    Melchior, M B; van Osch, M H J; Lam, T J G M; Vernooij, J C M; Gaastra, W; Fink-Gremmels, J

    2011-12-01

    Staphylococcus aureus is one of the most prevalent causes of bovine mastitis. The antimicrobial treatment of this disease is currently based on antimicrobial susceptibility tests according to Clinical and Laboratory Standards Institute standards. However, various authors have shown a discrepancy between the results of this standard susceptibility test and the actual cure rate of the applied antimicrobial treatment. Increasing evidence suggests that in vivo biofilm formation by Staph. aureus, which is not assessed in the antimicrobial susceptibility tests, is associated with this problem, resulting in disappointing cure rates, especially for infections of longer duration. Previous data obtained with a limited number of strains showed that the extended biofilm antimicrobial susceptibility (EBS) assay reveals differences between strains, which cannot be derived from a standard susceptibility test or from a 24-h biofilm susceptibility test. The objective of this study was to test a collection of Staph. aureus bovine mastitis strains in the EBS assay and to model the effect of antimicrobial exposure, duration of antimicrobial exposure, and genotype profile of the strains on antimicrobial susceptibility. With the results from a previous study with the same collection of strains, the effect of genotype represented by accessory gene regulator gene (agr-type), the presence of insertional sequence 257 (IS257), intercellular adhesion (ica), and the β-lactamase (blaZ) gene were entered as explanatory factors in a logistic regression model. The agr locus of Staph. aureus controls the expression of most of the virulence factors, represses the transcription of several cell wall-associated proteins, and activates several exoproteins during the post-exponential phase. The IS257 gene has been related to biofilm formation in vitro and was found earlier in 50% of the agr-type 2 strains. The ica gene cluster encodes for the production of an extracellular polysaccharide adhesin, termed

  17. Evaluation of biofilm formation using milk in a flow cell model and microarray characterization of Staphylococcus aureus strains from bovine mastitis.

    Science.gov (United States)

    Snel, G G M; Malvisi, M; Pilla, R; Piccinini, R

    2014-12-05

    It was hypothesized that biofilm could play an important role in the establishment of chronic Staphylococcus aureus bovine mastitis. The in vitro evaluation of biofilm formation can be performed either in closed/static or in flow-based systems. Efforts have been made to characterize the biofilm-forming ability of S. aureus mastitis isolates, however most authors used static systems and matrices other than UHT milk. It is not clear whether such results could be extrapolated to the mammary gland environment. Therefore, the present study aimed to investigate the biofilm-forming ability of S. aureus strains from subclinical bovine mastitis using the static method and a flow-based one. One hundred and twelve strains were tested by the classic tissue culture plate assay (TCP) and 30 out of them were also tested by a dynamic semi-quantitative assay using commercial UHT milk as culture medium (Milk Flow Culture, MFC) or Tryptic Soy Broth as control medium (TS Flow Culture, TSFC). Only 6 (20%) strains formed biofilm in milk under flow conditions, while 36.6% were considered biofilm-producers in TCP, and 93.3% produced biofilm in TSFC. No agreement was found between TCP, MFC and TSFC results. The association between strain genetic profile, determined by microarray, and biofilm-forming ability in milk was evaluated. Biofilm formation in MFC was significantly associated with the presence of those genes commonly found in bovine-associated strains, assigned to clonal complexes typically detected in mastitis. Based on our results, biofilm-forming potential of bovine strains should be critically analysed and tested applying conditions similar to mammary environment. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. In vitro efficacy of teat antiseptics against Staphylococcus aureus strains isolated from bovine mastitis

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    Renata Paoli Santos

    2016-08-01

    Full Text Available The process of teat disinfection is a widely accepted component of successful mastitis control programs by reducing the number of bacteria on the teat skin and healing teat lesions. For contagious pathogens such as Staphylococcus aureus, post-milking teat disinfection remains a simple, effective and economical practice for prevention of new intramammary infections (IMIs of lactating dairy cows. Despite the universal acceptance of teat dipping as a method of mastitis control, variations in the susceptibility and resistance profile of mastitis pathogens among antiseptics have been described. Thus, here we sought to explore the in vitro efficacy of the followings antiseptics against S. aureus isolated from IMIs: chlorhexidine (2.0%, chlorine (2.5%, quarternary ammonium (4.0%, lactic acid (2.0% and iodine (0.6%. We used 50 S. aureus strains isolated from bovine IMIs from 50 dairy herds located at Minas Gerais, São Paulo, Paraná and Rio Grande do Sul States (Brazil. The antiseptics were evaluated at four different specific intervals (15, 30, 60 and 300 s. We found a higher activity for quarternary ammonium and chlorhexidine against S. aureus at all time-points, followed by iodine and then chlorine. Lactic acid treatment produced the worst results for all time-points and strains. Due to variations in the sensitivity and resistance profile of antiseptics against S. aureus isolated from IMIs, the effectiveness of the antiseptics against the major mastitis pathogens should be periodically evaluated in dairy farms in an attempt to reduce the rate of new IMIs in the herd.

  19. Caracterização de biótipos de Staphylococcus aureus isolados de mastite bovina Biotyping of Staphylococcus aureus strains isolated from bovine mastitis

    Directory of Open Access Journals (Sweden)

    M.A.V.P. Brito

    2000-10-01

    Full Text Available Duzentos e dezoito amostras de Staphylococcus aureus, isoladas de infecção intramamária de vacas de 44 rebanhos leiteiros, foram classificadas em biótipos de acordo com os testes de produção de estafiloquinase (K, beta-hemolisina (beta , coagulação do plasma bovino (Pl e crescimento na presença de cristal violeta (CV. As amostras foram distribuídas em 10 biótipos e 63 delas foram classificadas nas ecovariedades bovina (35, ovina (17, aviária (10 e humana (1 e 155 não apresentaram características específicas de hospedeiro. Estas últimas podem ser isoladas de homem, cabra, coelho, suíno, alimentos e de mastite bovina. O biótipo 1, encontrado com maior freqüência (37,2%, apresentou o padrão K (-, beta (+, Pl (- e CV (azul. Em sete rebanhos nos quais se examinaram 10 ou mais amostras, verificou-se que, apesar da ocorrência simultânea de mais de um biótipo por rebanho, houve predominância de um sobre os demais.Two hundred and eighteen strains of Staphylococcus aureus isolated from bovine intramammary infections, obtained from 44 different dairy herds, were classified in biotypes based on staphylokinase (K and beta-haemolysin (beta production, bovine plasma coagulation (Pl and growth on crystal violet agar (CV. The strains were assigned to 10 different types, with 63 in the bovine (35, ovine (17, poultry (10 and human (1 ecovars and 155 in non-host specific biotypes. The latter can be isolated from man, goat, rabbit, pig, food, and bovine mastitis. The biotype 1, with reaction pattern K (-, beta (+, Pl (- and CV (blue, was the most frequently found (37,2%. From seven herds ten or more strains were examined. It was found that in spite of the presence of different biotypes per herd, there was always one prevalent biotype.

  20. Investigation of biofilm forming ability in Staphylococci causing bovine mastitis using phenotypic and genotypic assays.

    Science.gov (United States)

    Darwish, Samah F; Asfour, Hanaa A E

    2013-01-01

    A total of 40 S. aureus and 68 coagulase negative Staphylococcus (CNS) isolates from bovine subclinical mastitis were investigated for their ability to form biofilm as one of the most important virulence factors.Using Congo Red Agar (CRA) method, 32.5%, 35%, and 32.5% of S. aureus strains were strong, intermediate, and negative biofilm producers, while in CNS the percentages were 29.5%, 42.6%, and 27.9%, respectively. By microtiter plate (MTP) method, 52.5%, 27.5%, and 20% of S. aureus isolates were strong, moderate, and weak biofilm producers, while in CNS the percentages were 44%, 30.9%, and 19.2%, respectively. Indian ink staining was used to detect the EPS layer of biofilm producers. All isolates were screened for presence of biofilm related genes, eno, icaA, icaD, and bap. In S. aureus isolates, the positive rates of eno, icaA, icaD, and bap genes were 75%, 15%, 62.5%, and 2.5% while in CNS were 92.6%, 5.9%, 47.1%, and 4.4%, respectively. The eno gene had the highest rate while the bap gene had the lowest rate. Presence of icaA and icaD genes was not always correlated with biofilm production. This study demonstrated high prevalence of Staphylococcus biofilm producers among bovine mastitis in Egypt. Therefore, attention must be paid toward implementation of new ways for effective treatment of such infections.

  1. Investigation of Biofilm Forming Ability in Staphylococci Causing Bovine Mastitis Using Phenotypic and Genotypic Assays

    Directory of Open Access Journals (Sweden)

    Samah F. Darwish

    2013-01-01

    Full Text Available A total of 40 S. aureus and 68 coagulase negative Staphylococcus (CNS isolates from bovine subclinical mastitis were investigated for their ability to form biofilm as one of the most important virulence factors.Using Congo Red Agar (CRA method, 32.5%, 35%, and 32.5% of S. aureus strains were strong, intermediate, and negative biofilm producers, while in CNS the percentages were 29.5%, 42.6%, and 27.9%, respectively. By microtiter plate (MTP method, 52.5%, 27.5%, and 20% of S. aureus isolates were strong, moderate, and weak biofilm producers, while in CNS the percentages were 44%, 30.9%, and 19.2%, respectively. Indian ink staining was used to detect the EPS layer of biofilm producers. All isolates were screened for presence of biofilm related genes, eno, icaA, icaD, and bap. In S. aureus isolates, the positive rates of eno, icaA, icaD, and bap genes were 75%, 15%, 62.5%, and 2.5% while in CNS were 92.6%, 5.9%, 47.1%, and 4.4%, respectively. The eno gene had the highest rate while the bap gene had the lowest rate. Presence of icaA and icaD genes was not always correlated with biofilm production. This study demonstrated high prevalence of Staphylococcus biofilm producers among bovine mastitis in Egypt. Therefore, attention must be paid toward implementation of new ways for effective treatment of such infections.

  2. Antimicrobial resistant coagulase positive Staphylococcus aureus ...

    African Journals Online (AJOL)

    ADEYEYE

    S. aureus is associated with many clinical syndromes including tenosynovitis, omphalitis, femoral head necrosis, .... Markey, 2008) where occurrence of multidrug ... Staphylococcus aureus isolates from bovine mastitis in. Denmark. Veterinary.

  3. Characterization of Staphylococcus aureus isolates from raw milk sources in Victoria, Australia.

    Science.gov (United States)

    McMillan, Kate; Moore, Sean C; McAuley, Catherine M; Fegan, Narelle; Fox, Edward M

    2016-07-29

    Highly pathogenic strains of Staphylococcus aureus can cause disease in both humans and animals. In animal species, including ruminants, S. aureus may cause severe or sub-clinical mastitis. Dairy animals with mastitis frequently shed S. aureus into the milk supply which can lead to food poisoning in humans. The aim of this study was to use genotypic and immunological methods to characterize S. aureus isolates from milk-related samples collected from 7 dairy farms across Victoria. A total of 30 S. aureus isolates were collected from milk and milk filter samples from 3 bovine, 3 caprine and 1 ovine dairy farms across Victoria, Australia. Pulsed Field Gel Electrophoresis (PFGE) identified 11 distinct pulsotypes among isolates; all caprine and ovine isolates shared greater than 80 % similarity regardless of source. Conversely, bovine isolates showed higher diversity. Multi-Locus Sequence Typing (MLST) identified 5 different sequence types (STs) among bovine isolates, associated with human or ruminant lineages. All caprine and ovine isolates were ST133, or a single allele variant of ST133. Two new novel STs were identified among isolates in this study (ST3183 and ST3184). With the exception of these 2 new STs, eBURST analysis predicted all other STs to be founding members of their associated clonal complexes (CCs). Analysis of genetic markers revealed a diverse range of classical staphylococcal enterotoxins (SE) among isolates, with 11 different SEs identified among bovine isolates, compared with just 2 among caprine and ovine isolates. None of the isolates contained mecA, or were resistant to oxacillin. The only antibiotic resistance identified was that of a single isolate resistant to penicillin; this isolate also contained the penicillin resistance gene blaZ. Production of SE was observed at 16 °C and/or 37 °C in milk, however no SE production was detected at 12 °C. Although this study characterized a limited number of isolates, bovine-associated isolates

  4. Impairments of mecA gene detection in bovine Staphylococcus spp.

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    Dayanne Araújo de Melo

    2014-09-01

    Full Text Available Staphylococcus aureus antimicrobial resistance, especially to beta-lactams, favors treatment failures and its persistence in herd environment. This work aimed to develop a more specific primer for mecA gene detection based on the comparison of the conserved regions from distinct host origins and also investigated the presence of homologue mecA LGA251 in bovine strains. A total of 43 Staphylococcus spp. were included in this study, comprising 38 bovine S. aureus, two human and three equine coagulase-negative staphylococci (CNS. Phenotypical methicillin-resistance detection was performed through oxacillin agar-screening and cefoxitin disk-diffusion test. None isolate tested positive for mecA LGA251 gene. For mecA gene PCR, new primers were designed based on the sequences of human S. aureus (HE681097 and bovine S. sciuri (AY820253 mecA. The new primers based on the S. aureus mecA sequence amplified fragments of human and equine CNS and the ones based on S. sciuri mecA sequence only yielded fragments for S. aureus bovine strains. Multiples alignments of mecA gene sequences from bovine, human and equine revealed punctual but significant differences in bovine strains that can lead to the mecA gene detection impairment. The observed divergences of mecA gene sequences are not a matter of animal or human origin, it is a specificity of bovine samples.

  5. Biofilm production and beta-lactamic resistance in Brazilian Staphylococcus aureus isolates from bovine mastitis

    Directory of Open Access Journals (Sweden)

    Viviane Figueira Marques

    Full Text Available Abstract Staphylococcus spp. play an important role in the etiology of bovine mastitis. Staphylococcus aureus is considered the most relevant species due to the production of virulence factors such as slime, which is required for biofilm formation. This study aimed to evaluate biofilm production and its possible relation to beta-lactamic resistance in 20 S. aureus isolates from bovine mastitic milk. The isolates were characterized by pheno-genotypic and MALDI TOF-MS assays and tested for genes such as icaA, icaD, bap, agr RNAIII, agr I, agr II, agr III, and agr IV, which are related to slime production and its regulation. Biofilm production in microplates was evaluated considering the intervals determined along the bacterial growth curve. In addition, to determine the most suitable time interval for biofilm analysis, scanning electron microscopy was performed. Furthermore, genes such as mecA and blaZ that are related to beta-lactamic resistance and oxacillin susceptibility were tested. All the studied isolates were biofilm producers and mostly presented icaA and icaD. The Agr type II genes were significantly prevalent. According to the SEM, gradual changes in the bacterial arrangement were observed during biofilm formation along the growth curve phases, and the peak was reached at the stationary phase. In this study, the penicillin resistance was related to the production of beta-lactamase, and the high minimal bactericidal concentration for cefoxitin was possibly associated with biofilm protection. Therefore, further studies are warranted to better understand biofilm formation, possibly contributing to our knowledge about bacterial resistance in vivo.

  6. Taming C-terminal peptides of Staphylococcus aureus leukotoxin M for B-cell response: Implication in improved subclinical bovine mastitis diagnosis and protective efficacy in vitro.

    Science.gov (United States)

    Padmaja, Radhakrishnan Jayasree; Halami, Prakash Motiram

    2016-09-01

    Leukotoxin M/F'-PV (LukM/F'-PV) produced by bovine mastitis causing Staphylococcus aureus structurally comprises three domains, the β-sandwich, rim and stem domain. The rim and stem domains interacting with target cell membrane lipid rafts contributes to the virulent trait of the toxin. In the present study, two facts were hypothesized that neutralization of these domains will ebb LukM/F'-PV leukotoxicity. Secondly, the neutralizing antibodies can improve the leukotoxin detection sensitivity in bovine mastitis milk samples. The in silico mapping of S. aureus LukM C-termini comprising these domains predicted seven linear B-cell antigenic epitopes. The immune response of C-terminal truncated recombinant peptides rCtM19 (19 kDa; near carboxy-terminal) having four epitopes and rCtM15 (15 kDa; C-terminal) with three epitopes were evaluated for their diagnostic and neutralization potential. Anti-rCtM19 and anti-rCtM15 antibodies with enhanced immunogenicity had the most striking outcome in IgG-ELISA for detecting native determinants of leukotoxin. For the obtained ELISA values, ROC curve inferred a cut-off score of >0.102 OD405. The assay sensitivity in the range of 90-96% along with 100% specificity and AUC of 0.93-0.98 categorized subclinical and clinical from healthy bovine milk samples. As observed through in vitro neutralization and LDH assays, C-terminus specific antibodies (1:42 titer) deactivating leukotoxicity abolished LukM from interacting with lipid bilayer and LukF for forming pores on bovine neutrophil membrane. As a proof of concept, it was proved that peptide antibodies can be a more specific serodiagnostic and passive therapeutic molecules. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Screening of medicinal plants for antibacterial activities on Staphylococcus aureus strains isolated from bovine mastitis Screening de plantas medicinais com atividade antimicrobiana contra cepas de Staphylococcus aureus isoladas de mastite bovina

    Directory of Open Access Journals (Sweden)

    Marisa A. N. Diaz

    2010-11-01

    Full Text Available Staphylococcus aureus is the main causative agent of bovine mastitis. The activity of several extracts from ten medicinal plants traditionally used in Brazil as antiseptic was investigated against fifteen strains of Staphylococcus aureus isolated from animals with mastitis manifestation by the disc diffusion method and broth microdilution assay. The interference of the extracts on cell in the form of adherent colonies was also evaluated. MIC values ranged from 0.5 mg/mL to 1.0 mg/mL and biofilm inhibitory concentration (BIC were between 0.25 mg/mL and 0.8 mg/mL. Results revealed the potential of extracts of Senna macranthera, Artemisia absinthium, Cymbopogon nardus and Baccharis dracunculifolia as antibacterial agents against S. aureus strains isolated from bovine mastitis and support the possible use of these phytotherapic agents in the clinical management of the disease.Staphylococcus aureus é o principal agente causador de mastite bovina. A atividade de diversos extratos de dez plantas medicinais tradicionalmente usadas no Brasil como anti-sépticas foi investigada contra quinze cepas de Staphylococcus aureus isoladas de animais com manifestação de mastite pelo método de difusão em ágar e ensaio de microdiluição. A interferência dos extratos na célula bacteriana em forma de colônias aderidas também foi avaliada. Os valores de MIC variaram de 0.5 mg/mL a 1.0 mg/mL e a concentração inibitória de biofilme (BIC variou de 0.25 mg/mL a 0.8 mg/mL. Os resultados revelaram o potencial dos extratos de Senna macranthera, Artemisia absinthium, Cymbopogon nardus e Baccharis dracunculifolia como agentes antibacterianos contra cepas de S. aureus isolados de mastite bovina e suportam o possível uso destas plantas no manejo clínico da doença.

  8. Genotyping of Staphylococcus aureus in bovine mastitis and correlation to phenotypic characteristics.

    Science.gov (United States)

    Artursson, Karin; Söderlund, Robert; Liu, Lihong; Monecke, Stefan; Schelin, Jenny

    2016-09-25

    Reducing the prevalence of mastitis caused by Staphylococcus aureus (S. aureus) is essential to improve animal health and reduce economic losses for farmers. The clinical outcome of acute mastitis and risk of progression to persistent mastitis can, at least to some extent, be related to genetic variants of the strain causing the infection. In the present study we have used microarrays to investigate the presence of virulence genes in S. aureus isolates from dairy cows with acute clinical mastitis (n=70) and correlated the findings to other genotypic and phenotypic characteristics. Among the most commonly found virulence factors were genes encoding several hemolysin types, leukocidins D and lukM/lukF-P83, clumping factors A and B, fibrinogen binding protein and fibronectin-binding protein A. Some virulence factors e.g. fibronectin-binding protein B and Staphylococcus aureus surface protein G were less common. Genes coding for several staphylococcal enterotoxins and toxic shock syndrome toxin-1 (TSST-1) were commonly found, especially in one major pulsotype. No beta-lactamase genes were found in any common pulsotype, while present in some rare pulsotypes, indicated to be of human origin. Production of TSST-1, enterotoxins, hemolysins and beta-lactamase could all be positively correlated to presence of the corresponding genes. This study reveals a number of genotypic differences and similarities among common and rare pulsotypes of S. aureus from cases of mastitis in Sweden. The results could help the design of diagnostic tools to guide on-farm interventions according to the expected impact on udder health from a specific S. aureus genotype. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Molecular analysis of virulent genes (coa and spa) of staphylococcus aureus involved in natural cases of bovine mastitis

    International Nuclear Information System (INIS)

    Khan, A.; Javed, M.T.; Mahmood, F.; Hussain, R.

    2013-01-01

    The present study was undertaken to determine the distribution and genotypic characteristics of Staphylococcus aureus isolates recovered from naturally occurring mastitis in cattle and buffaloes. For this purpose a total of 1445 lactating cattle (653) and buffaloes (792) present at two experimental livestock farms Okara (Bahadarnagar) and Sahiwal (Qadiarabad), in and around district Faisalabad and slaughtered at an abattoir due to low milk yield and were screened for mastitis. California Mastitis Test (CMT) was used to detect sub clinical mastitis. The positive quarter milk samples were collected for culturing of S. aureus isolates. taphylococcus aureus isolates were identified on the basis of growth features, biochemical characteristics, coagulase test and as well as amplification of coagulase (coa) and spa (spa-X) genes specific to its virulence. S. aureus isolates (n=265) were characterized by Polymerase chain reaction to determine the frequency of coagulase (coa) and spa (spa-X) genes. From these isolates the amplification of the coagulase (coa) gene yielded three different PCR products approximately 204bp to 490bp while spa (spa-X) gene produced five different products ranging in size from 190bp to 320bp. PCR revealed that from all the coagulase positive S. aureus isolates 261(98.5%) had spa (spa-X) gene. The results of the present study indicated that S. aureus isolates recovered from bovine mastitis were genetically different within and among the various herds which may provide essential and valuable strategies to control staphylococcal infections in future. (author)

  10. Molecular analysis of virulent genes (coa and spa) of staphylococcus aureus involved in natural cases of bovine mastitis

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A.; Javed, M. T.; Mahmood, F. [University of Agriculture, Faisalabad (Pakistan). Dept. of Pathology; Hussain, R. [The Islamia Univ. of Bahawalpur, Pakistan (Pakistan). Dept. of Veterinary and Animal Sciences

    2013-12-15

    The present study was undertaken to determine the distribution and genotypic characteristics of Staphylococcus aureus isolates recovered from naturally occurring mastitis in cattle and buffaloes. For this purpose a total of 1445 lactating cattle (653) and buffaloes (792) present at two experimental livestock farms Okara (Bahadarnagar) and Sahiwal (Qadiarabad), in and around district Faisalabad and slaughtered at an abattoir due to low milk yield and were screened for mastitis. California Mastitis Test (CMT) was used to detect sub clinical mastitis. The positive quarter milk samples were collected for culturing of S. aureus isolates. taphylococcus aureus isolates were identified on the basis of growth features, biochemical characteristics, coagulase test and as well as amplification of coagulase (coa) and spa (spa-X) genes specific to its virulence. S. aureus isolates (n=265) were characterized by Polymerase chain reaction to determine the frequency of coagulase (coa) and spa (spa-X) genes. From these isolates the amplification of the coagulase (coa) gene yielded three different PCR products approximately 204bp to 490bp while spa (spa-X) gene produced five different products ranging in size from 190bp to 320bp. PCR revealed that from all the coagulase positive S. aureus isolates 261(98.5%) had spa (spa-X) gene. The results of the present study indicated that S. aureus isolates recovered from bovine mastitis were genetically different within and among the various herds which may provide essential and valuable strategies to control staphylococcal infections in future. (author)

  11. Acute phase proteins in bovine milk in an experimental model of Staphylococcus aureus subclinical mastitis

    DEFF Research Database (Denmark)

    Eckersall, P D; Young, F J; Nolan, A M

    2006-01-01

    and serum amyloid A increase in serum during mastitis. The concentrations of these proteins were determined in an experimental model using a field strain of Staphylococcus aureus to induce subclinical mastitis in dairy cows. The expression of mRNA coding for these proteins was assessed and the presence of M......The objectives were to establish the origin of 2 acute phase proteins in milk during subclinical bovine mastitis and to characterize the relationship between those proteins in milk and blood. Haptoglobin (Hp) and mammary-associated serum amyloid A (M-SAA3) appear in milk during mastitis, whereas Hp...

  12. Frequency of alpha- and beta-haemolysin in Staphylococcus aureus of bovine and human origin - A comparison between pheno- and genotype and variation in phenotypic expression

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Larsen, H.D.; Eriksen, N.H.R.

    1999-01-01

    The phenotypic expression of haemolysins and the presence of genes encoding alpha and beta-haemolysin were determined in 105 Sraphylococcus aureus isolates from bovine mastitis, 100 isolates from the nostrils of healthy humans, and 60 isolates from septicaemia in humans. Furthermore, the possible...... change in expression of haemolysins after subcultivation in human and bovine blood and milk was studied in selected isolates. alpha-haemolysin was expressed phenotypically in 39 (37%) of the bovine isolates, in 59 (59%) of the human carrier isolates, and in 40 (67%) of the isolates from septicaemia. beta......-haemolysin was expressed in 76 (72%) bovine, 11 (11%) carrier, and 8 (13%) septicaemia isolates. Significantly more bovine than human isolates expressed beta-haemolysin and significantly fewer expressed alpha-haemolysin. Genotypically, the gene encoding alpha-haemolysin was detected in all isolates. A significant...

  13. Bacteriophage ΦSA012 Has a Broad Host Range against Staphylococcus aureus and Effective Lytic Capacity in a Mouse Mastitis Model

    Directory of Open Access Journals (Sweden)

    Hidetomo Iwano

    2018-01-01

    Full Text Available Bovine mastitis is an inflammation of the mammary gland caused by bacterial infection in dairy cattle. It is the most costly disease in the dairy industry because of the high use of antibiotics. Staphylococcus aureus is one of the major causative agents of bovine mastitis and antimicrobial resistance. Therefore, new strategies to control bacterial infection are required in the dairy industry. One potential strategy is bacteriophage (phage therapy. In the present study, we examined the host range of previously isolated S. aureus phages ΦSA012 and ΦSA039 against S. aureus strains isolated from mastitic cows. These phages could kill all S. aureus (93 strains from 40 genotypes and methicillin-resistant S. aureus (six strains from six genotypes strains tested. Using a mouse mastitis model, we demonstrated that ΦSA012 reduced proliferation of S. aureus and inflammation in the mammary gland. Furthermore, intravenous or intraperitoneal phage administration reduced proliferation of S. aureus in the mammary glands. These results suggest that broad host range phages ΦSA012 is potential antibacterial agents for dairy production medicine.

  14. Pharmacokinetics of azithromycin in lactating dairy cows with subclinical mastitis caused by Staphylococcus aureus.

    Science.gov (United States)

    Lucas, M F; Errecalde, J O; Mestorino, N

    2010-04-01

    Azithromycin is a time-dependent antimicrobial with long persistence. The main characteristics of azithromycin suggest that it could be useful for treating bovine mastitis caused by Staphylococcus aureus. To investigate this possibility, its pharmacokinetic (PK) behavior was studied. Six Holstein lactating cows with subclinical mastitis were administered two 10 mg/kg intramuscular (i.m.) doses of azithromycin, with a 48-h interval. Milk and plasma concentrations were measured by microbiological assay. The MIC(90) was determined in 51 S. aureus isolations to calculate pharmacokinetic/pharmacodynamic (PK/PD) parameters. Milk maximal concentration (C(max)) was 7.76 +/- 1.76 microg/mL (16.67 h post-first administration) and 7.82 +/- 2.18 microg/mL (14 h post-2(nd) administration). In plasma C(max) was 0.18 +/- 0.03 microg/mL (2 h post-1(rst) administration) and 0.11 +/- 0.03 microg/mL (14 h post-2(nd) administration). Azithromycin was eliminated from the milk with a half-life (T(1/2)lambda) of 158.26 +/- 137.7 h after 2(nd) administration, meanwhile plasma T(1/2)lambda resulted shorter(13.97 +/- 11.1 h). The mean area under the concentration vs. time curve from 0 to 24 h (AUC(0-24h)) was 153.82 +/- 34.66 microg.h/mL in milk secretion and 2.61 +/- 0.59 microgxh/mL in plasma. Infection presence in the quarters had a significant effect (P time curve from 0 to infinity (AUC(0-infinity)) and clearance from the mammary gland (Cl(mam)/F). Moreover, it had influence on milk bioavailability (F(milk)), T(1/2)lambda, AUC(0-infinity) and mean residence time (MRT) in milk, which values resulted increased in mastitic quarters. In this study, it was determined that the production level and the mammary health status have an influence on PK parameters of azithromycin treatments in bovine mastitis.

  15. Bactericidal effect of bovine lactoferrin, LFcin, LFampin and LFchimera on antibiotic-resistant Staphylococcus aureus and Escherichia coli.

    Science.gov (United States)

    Flores-Villaseñor, Héctor; Canizalez-Román, Adrian; Reyes-Lopez, Magda; Nazmi, Kamram; de la Garza, Mireya; Zazueta-Beltrán, Jorge; León-Sicairos, Nidia; Bolscher, Jan G M

    2010-06-01

    Increased prevalence of antibiotic-resistant bacteria has become a major threat to the health sector worldwide due to their virulence, limited therapeutic options and distribution in both hospital and community settings. Discovery and development of new agents to combat antibiotic-resistant bacteria is thus needed. This study therefore aimed to evaluate the ability of bovine lactoferrin (LF), peptides from two antimicrobial domains lactoferricin B (LFcin17-30) and lactoferrampin (LFampin265-284) and a chimeric construct (LFchimera) containing both peptides, as potential bactericidal agents against clinical isolates of antibiotic-resistant Staphylococcus aureus and Escherichia coli. Results in kinetics of growth show that LF chimera and peptides inhibited the growth of both bacterial species. By confocal microscopy and flow cytometry it was observed that LF and FITC-labeled peptides are able to interact with these bacteria and cause membrane permeabilization, as monitored by propidium iodide staining, these effects were decreased by preincubation with lipopolysaccharide in E. coli. By electron microscopy, a clear cellular damage was observed in bacteria after treatments with LFchimera and peptides, suggesting that interaction and membrane disruption are probably involved as a mechanism of action. In conclusion, results show that LFchimera, LF and peptides have potential as bactericidal agents in the antibiotic-resistant strains of S. aureus and E. coli and also the work strongly suggest that LFcin17-30 and LFampin265-284 acts synergistically with antibiotics against multidrug resistant EPEC and MRSA in vitro.

  16. A PiggyBac mediated approach for lactoferricin gene transfer in bovine mammary epithelial stem cells for management of bovine mastitis.

    Science.gov (United States)

    Sharma, Neelesh; Huynh, Do Luong; Kim, Sung Woo; Ghosh, Mrinmoy; Sodhi, Simrinder Singh; Singh, Amit Kumar; Kim, Nam Eun; Lee, Sung Jin; Hussain, Kafil; Oh, Sung Jong; Jeong, Dong Kee

    2017-11-28

    The antibacterial and anti-inflammatory properties of lactoferricin have been ascribed to its ability to sequester essential iron. The objective of the study was to clone bovine lactoferricin ( LFcinB ) gene into PiggyBac Transposon vector, expression study in the bovine mammary epithelial stem cells (bMESCs) and also to determine the antimicrobial property of recombinant LFcinB against bovine mastitis-causing organisms. The PiggyBac-LFcinB was transfected into bMESCs by electroporation and a three fold of LFcinB secretion was observed in the transfected bMESCs medium by ELISA assay. Furthermore, the assessment of antimicrobial activity against mastitis causing pathogens Staphylococcus aureus and Escherichia coli demonstrated convincing evidence to prove strong antibacterial activity of LFcinB with 14.0±1.0 mm and 18.0±1.5 mm zone of inhibition against both organisms, respectively. The present study provides the convincing evidence to suggest the potential of PiggyBac transposon system to transfer antibacterial peptide into bMESCs or cow mammary gland and also pave the way to use bovine mammary gland as the bioreactors. Simultaneously, it also suggest toward commercial utilization of LFcinB bioreactor system in pharmaceutical industry.

  17. Determination of the minimum inhibitory concentration (MIC and mutant prevention concentration (MPC of selected antimicrobials in bovine and swine Pasteurella multocida, Escherichia coli, and Staphylococcus aureus isolates

    Directory of Open Access Journals (Sweden)

    Kateřina Nedbalcová

    2015-01-01

    Full Text Available We compared the values of the minimum inhibitory concentration (MIC and mutant prevention concentration (MPC values ​​of three antimicrobial agents for 72 bovine isolates of Pasteurella multocida, 80 swine isolates of P. multocida, 80 bovine isolates of Escherichia coli, 80 swine isolates of E. coli, and 80 isolates of Staphylococcus aureus from bovine mastitis. The ratio of MIC90​​/MPC90 which limited mutant selection window (MSW was ≤ 0.12/4 mg/l for enrofloxacin, 0.5/≥ 64 mg/l for florfenicol and 4/≥ 128 mg/l for tulathromycin in bovine P. multocida isolates, ≤ 0.12/2 mg/l for enrofloxacin, 0.5/≥ 64 mg/l for florfenicol and 4/≥ 128 mg/l for tulathromycin in swine P. multocida isolates, 1/16 mg/l for enrofloxacin, 8/≥ 64 mg/l for florfenicol and 8/≥ 128 mg/l for tulathromycin in bovine E. coli isolates, 0.5/16 mg/l for enrofloxacin, ≥ 64/≥ 64 mg/l for florfenicol and 8/≥ 128 mg/l for tulathromycin in swine E. coli isolates, and 0.25/16 mg/l for enrofloxacin, 4/≥ 64 mg/l for florfenicol and 4/≥ 128 mg/l for tulathromycin in S. aureus isolates. These findings indicate that the dosage of antimicrobial agents to achieve serum concentration equal to or higher than MPC could reduce selection of resistant bacterial subpopulation.

  18. Mastite subclínica causada por Staphylococcus aureus: custo-benefício da antibioticoterapia de vacas em lactação Subclinical mastitis caused by Staphylococcus aureus: cost benefit analysis of antibiotic therapy in lactating cows

    Directory of Open Access Journals (Sweden)

    L.F. Zafalon

    2007-06-01

    Full Text Available Avaliou-se a relação custo-benefício do tratamento da mastite subclínica bovina causada por Staphylococcus aureus. Foram selecionados 270 quartos mamários com mastite subclínica e sadios, divididos em quatro grupos de acordo com o estádio de lactação e o tratamento. O grupo 1 foi formado por animais entre 10 e 60 dias da lactação e tratados contra mastites; o grupo 2 incluiu animais entre 61 dias da lactação e dois meses antes da secagem e tratados contra mastite; o grupo 3 foi formado por animais entre 10 e 60 dias da lactação, não tratados contra mastite; e o grupo 4 foi formado por animais entre 61 dias em lactação e dois meses antes da secagem, não tratados. O tratamento foi realizado pela infusão intramamária de 150mg de gentamicina, uma vez ao dia. A reavaliação foi efetuada após 30 dias. Para os cálculos dos custos com o tratamento, foram considerados uma prevalência de S. aureus de 5% e os gastos com medicamento, descarte do leite, antibiograma e mão-de-obra. Observou-se redução de 2% e 14% das receitas nos grupos 1 e 2, respectivamente, quando comparada com as receitas obtidas antes do tratamento, demonstrando ser economicamente inviável o tratamento da mastite subclínica bovina causada por S. aureus, durante a lactação.Economic evaluation of the treatment bovine subclinical mastitis caused by S. aureus was evaluated. Two hundred and seventy udder quarters with or without subclinical mastitis were distributed into four groups, in conformity to lactational stage and treatments. Group 1 included animals treated between 10 and 60 days of lactation; group 2 included animals treated from 61 days of lactation to two months before drying; group 3 included animals no treated between 10 and 60 days of lactation; group 4 included animals no treated from 61 days of lactation to two months before drying. Treatment with gentamicin (150mg was accomplished by intramammary doses, once a day, after performing sensitivity

  19. Mammary Gland Pathology Subsequent to Acute Infection with Strong versus Weak Biofilm Forming Staphylococcus aureus Bovine Mastitis Isolates: A Pilot Study Using Non-Invasive Mouse Mastitis Model.

    Science.gov (United States)

    Gogoi-Tiwari, Jully; Williams, Vincent; Waryah, Charlene Babra; Costantino, Paul; Al-Salami, Hani; Mathavan, Sangeetha; Wells, Kelsi; Tiwari, Harish Kumar; Hegde, Nagendra; Isloor, Shrikrishna; Al-Sallami, Hesham; Mukkur, Trilochan

    2017-01-01

    Biofilm formation by Staphylococcus aureus is an important virulence attribute because of its potential to induce persistent antibiotic resistance, retard phagocytosis and either attenuate or promote inflammation, depending upon the disease syndrome, in vivo. This study was undertaken to evaluate the potential significance of strength of biofilm formation by clinical bovine mastitis-associated S. aureus in mammary tissue damage by using a mouse mastitis model. Two S. aureus strains of the same capsular phenotype with different biofilm forming strengths were used to non-invasively infect mammary glands of lactating mice. Biofilm forming potential of these strains were determined by tissue culture plate method, ica typing and virulence gene profile per detection by PCR. Delivery of the infectious dose of S. aureus was directly through the teat lactiferous duct without invasive scraping of the teat surface. Both bacteriological and histological methods were used for analysis of mammary gland pathology of mice post-infection. Histopathological analysis of the infected mammary glands revealed that mice inoculated with the strong biofilm forming S. aureus strain produced marked acute mastitic lesions, showing profuse infiltration predominantly with neutrophils, with evidence of necrosis in the affected mammary glands. In contrast, the damage was significantly less severe in mammary glands of mice infected with the weak biofilm-forming S. aureus strain. Although both IL-1β and TNF-α inflammatory biomarkers were produced in infected mice, level of TNF-α produced was significantly higher (pmastitis model, and offers an opportunity for the development of novel strategies for reduction of mammary tissue damage, with or without use of antimicrobials and/or anti-inflammatory compounds for the treatment of bovine mastitis.

  20. Mammary Gland Pathology Subsequent to Acute Infection with Strong versus Weak Biofilm Forming Staphylococcus aureus Bovine Mastitis Isolates: A Pilot Study Using Non-Invasive Mouse Mastitis Model.

    Directory of Open Access Journals (Sweden)

    Jully Gogoi-Tiwari

    Full Text Available Biofilm formation by Staphylococcus aureus is an important virulence attribute because of its potential to induce persistent antibiotic resistance, retard phagocytosis and either attenuate or promote inflammation, depending upon the disease syndrome, in vivo. This study was undertaken to evaluate the potential significance of strength of biofilm formation by clinical bovine mastitis-associated S. aureus in mammary tissue damage by using a mouse mastitis model.Two S. aureus strains of the same capsular phenotype with different biofilm forming strengths were used to non-invasively infect mammary glands of lactating mice. Biofilm forming potential of these strains were determined by tissue culture plate method, ica typing and virulence gene profile per detection by PCR. Delivery of the infectious dose of S. aureus was directly through the teat lactiferous duct without invasive scraping of the teat surface. Both bacteriological and histological methods were used for analysis of mammary gland pathology of mice post-infection.Histopathological analysis of the infected mammary glands revealed that mice inoculated with the strong biofilm forming S. aureus strain produced marked acute mastitic lesions, showing profuse infiltration predominantly with neutrophils, with evidence of necrosis in the affected mammary glands. In contrast, the damage was significantly less severe in mammary glands of mice infected with the weak biofilm-forming S. aureus strain. Although both IL-1β and TNF-α inflammatory biomarkers were produced in infected mice, level of TNF-α produced was significantly higher (p<0.05 in mice inoculated with strong biofilm forming S. aureus than the weak biofilm forming strain.This finding suggests an important role of TNF-α in mammary gland pathology post-infection with strong biofilm-forming S. aureus in the acute mouse mastitis model, and offers an opportunity for the development of novel strategies for reduction of mammary tissue damage

  1. Efficacy of recombinant bovine epidermal growth factor in the treatment of experimental subclinical Staphylococcus aureus mastitis in a ewe model.

    Science.gov (United States)

    Gabadage, Kamal; Chirino-Trejo, Manuel; Campbell, John; Luby, Christopher

    2017-01-01

    Staphylococcus aureus is the most common contagious mastitis pathogen of dairy cattle. Antimicrobial treatment of infected cattle results in variable cure rates. Epidermal growth factor (EGF) plays an important role in the modulation of host innate immune responses and the regulation of mammary epithelial regeneration, indicating that EGF may be useful as a treatment for mastitis. A pilot study was conducted to evaluate the efficacy of recombinant bovine EGF (rbEGF) for the treatment of S aureus intramammary infection (IMI) using an ovine model. Each ewe was experimentally infected with S aureus in both udder halves. One udder half of each ewe received one of two treatments: EGF (n=13) or pirlimycin (n=13). The contralateral udder half of each ewe received sterile saline as a control. The bacteriological cure rate following rbEGF was significantly lower (15 per cent) than that attained with pirlimycin hydrochloride (61 per cent) and did not differ from that following treatment with sterile saline. Cure rates following treatment with rbEGF were not significantly different to those following sterile saline. Given that EGF is associated with modulation of host immunity and wound healing, future studies into EGF should not focus on whether EGF increases cure rates of S aureus IMI.

  2. Hospitalizations and Deaths Caused by Methicillin-Resistant Staphylococcus aureus, United States, 1999?2005

    OpenAIRE

    Klein, Eili; Smith, David L.; Laxminarayan, Ramanan

    2007-01-01

    Hospital-acquired infections with Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA) infections, are a major cause of illness and death and impose serious economic costs on patients and hospitals. However, the recent magnitude and trend of these infections have not been reported. We used national hospitalization and resistance data to estimate the annual number of hospitalizations and deaths associated with S. aureus and MRSA from 1999 through 2005. During this period, t...

  3. Staphylococcus aureus sternal osteomyelitis: a rare cause of chest pain

    Directory of Open Access Journals (Sweden)

    Kaur M

    2015-10-01

    Full Text Available Chest pain is a common presenting symptom with a broad differential. Life-threatening cardiac and pulmonary etiologies of chest pain should be evaluated first. However, it is critical to perform a thorough assessment for other sources of chest pain in order to limit morbidity and mortality from less common causes. We present a rare case of a previously healthy 45 year old man who presented with focal, substernal, reproducible chest pain and Staphylococcus aureus bacteremia who was later found to have primary Staphylococcus aureus sternal osteomyelitis.

  4. Diversity and antimicrobial susceptibility profiling of staphylococci isolated from bovine mastitis cases and close human contacts.

    Science.gov (United States)

    Schmidt, T; Kock, M M; Ehlers, M M

    2015-09-01

    The objectives of this study were to examine the diversity of Staphylococcus spp. recovered from bovine intramammary infections and humans working in close contact with the animals and to evaluate the susceptibility of the staphylococcal isolates to different antimicrobials. A total of 3,387 milk samples and 79 human nasal swabs were collected from 13 sampling sites in the KwaZulu-Natal province of South Africa. In total, 146 Staph. aureus isolates and 102 coagulase-negative staphylococci (CNS) were recovered from clinical and subclinical milk samples. Staphylococcusaureus was isolated from 12 (15.2%) of the human nasal swabs and 95 representative CNS were recovered for further characterization. The CNS were identified using multiplex-PCR assays, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and tuf gene sequencing. Seven Staphylococcus spp. were identified among the CNS of bovine origin, with Staph.chromogenes (78.4%) predominating. The predominant CNS species recovered from the human nasal swabs was Staph.epidermidis (80%) followed by Staph.chromogenes (6.3%). The antimicrobial susceptibility of all staphylococcal isolates was evaluated using disk diffusion and was supplemented by screening for specific antimicrobial resistance genes. Ninety-eight (67.1%) Staph.aureus isolates of bovine origin were pansusceptible; 39 (26.7%) isolates were resistant to a single class, and 7 (4.8%) isolates were resistant to 2 classes of antimicrobials. Two Staph. aureus (1.4%) isolates were multidrug-resistant. Resistance to penicillin was common, with 28.8% of the bovine and 75% of the human Staph. aureus isolates exhibiting resistance. A similar observation was made with the CNS, where 37.3% of the bovine and 89.5% of the human isolates were resistant to penicillin. Multidrug-resistance was common among the human CNS, with 39% of the isolates exhibiting resistance to 3 or more classes of antimicrobials. The antimicrobial

  5. Technical note: Antimicrobial susceptibility of Portuguese isolates of Staphylococcus aureus and Staphylococcus epidermidis in subclinical bovine mastitis.

    Science.gov (United States)

    Nunes, S F; Bexiga, R; Cavaco, L M; Vilela, C L

    2007-07-01

    To evaluate the antimicrobial resistance traits of staphylococci responsible for subclinical bovine mastitis in Portugal, the minimum inhibitory concentrations (MIC) of 7 antimicrobial agents, frequently administered for mastitis treatment, were determined for 30 Staphylococcus aureus and 31 Staphylococcus epidermidis field isolates. Beta-lactamase production was detected through the use of nitrocefin-impregnated discs. The MIC that inhibited 90% of the isolates tested (MIC90) of penicillin, oxacillin, cefazolin, gentamicin, sulfamethoxazole/trimethoprim, oxytetracycline, and enrofloxacin were, respectively, 4, 0.5, 1, 1, 0.25, 0.25, and 0.06 microg/mL for Staph. aureus and > or = 64, 8, 1, 32, > or = 64, > or = 64, and 0.06 microg/mL for Staph. epidermidis. All Staph. aureus isolates showed susceptibility to oxacillin, cefazolin, gentamicin, sulphamethoxazole/trimethoprim, and enrofloxacin. Beta-lactamase production was detected in 20 of these isolates (66.7%), all of which were resistant to penicillin. Of the 31 Staph. epidermidis tested, 24 (77.4%) were beta-lactamase positive. All isolates were susceptible to both cefazolin and enrofloxacin. Nine Staph. epidermidis isolates were resistant to oxacillin, with MIC values ranging from 4 to 8 microg/mL. The MIC values of 5 antimicrobial agents tested were higher than those reported in other countries. Enrofloxacin was the only exception, showing lower MIC values compared with other reports. Overall, the antimicrobial agents tested in our study, with the exception of penicillin, were active against the 61 isolates studied.

  6. Prevalence of Staphylococcus aureus and of methicillin-resistant S. aureus clonal complexes in bulk tank milk from dairy cattle herds in Lombardy Region (Northern Italy).

    Science.gov (United States)

    Cortimiglia, C; Luini, M; Bianchini, V; Marzagalli, L; Vezzoli, F; Avisani, D; Bertoletti, M; Ianzano, A; Franco, A; Battisti, A

    2016-10-01

    Staphylococcus aureus is the most important causative agent of subclinical mastitis in cattle resulting in reduced milk production and quality. Methicillin-resistant S. aureus (MRSA) strains has a clear zoonotic relevance, especially in the case of occupational exposure. The aim of the study was to evaluate the prevalence of S. aureus and MRSA in bulk tank milk (BTM) from dairy cattle herds in the Lombardy Region (Northern Italy) and to identify the main MRSA circulating genotypes. MRSA strains were characterized by susceptibility testing, multi-locus sequence typing (MLST), spa typing and SCCmec typing. A total 844 BTM samples were analysed and S. aureus and MRSA were detected in 47·2% and 3·8% of dairy herds, respectively. MLST showed that the majority (28/32) of isolates belonged to the typical livestock-associated lineages: ST398, ST97 and ST1. Interestingly, in this study we report for the first time the new ST3211, a single locus variant of ST(CC)22, with the newly described 462 aroE allele. Our study indicates high diffusion of S. aureus mastitis and low, but not negligible, prevalence of MRSA in the considered area, suggesting the need for planning specific control programmes for bovine mastitis caused by S. aureus, especially when MRSA is implicated.

  7. Selective propensity of bovine jugular vein material to bacterial adhesions: An in-vitro study.

    Science.gov (United States)

    Jalal, Zakaria; Galmiche, Louise; Lebeaux, David; Villemain, Olivier; Brugada, Georgia; Patel, Mehul; Ghigo, Jean-Marc; Beloin, Christophe; Boudjemline, Younes

    2015-11-01

    Percutaneous pulmonary valve implantation (PPVI) using Melody valve made of bovine jugular vein is safe and effective. However, infective endocarditis has been reported for unclear reasons. We sought to assess the impact of valvular substrates on selective bacterial adhesion. Three valved stents (Melody valve, homemade stents with bovine and porcine pericardium) were tested in-vitro for bacterial adhesion using Staphylococcus aureus and Streptococcus sanguinis strains. Bacterial adhesion was higher on bovine jugular venous wall for S. aureus and on Melody valvular leaflets for S. sanguinis in control groups and significantly increased in traumatized Melody valvular leaflets with both bacteria (traumatized vs non traumatized: p=0.05). Bacterial adhesion was lower on bovine pericardial leaflets. Selective adhesion of S. aureus and S. sanguinis pathogenic strains to Melody valve tissue was noted on healthy tissue and increased after implantation procedural steps. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  8. Antimicrobial susceptibility, virulence genes, and randomly amplified polymorphic DNA analysis of Staphylococcus aureus recovered from bovine mastitis in Ningxia, China.

    Science.gov (United States)

    Wang, Dong; Zhang, Limei; Zhou, Xuezhang; He, Yulong; Yong, Changfu; Shen, Mingliang; Szenci, Otto; Han, Bo

    2016-12-01

    Staphylococcus aureusis the leading pathogen involved inbovine mastitis, but knowledgeabout antimicrobial resistance, virulence factors, and genotypes of Staphylococcus aureus resulting in bovine mastitis in Ningxia, China, is limited. Therefore, antimicrobial susceptibility, virulence gene, and randomly amplified polymorphic DNA (RAPD) analyses of Staph. aureus were carried out. A total of 327 milk samples from cows with clinical and subclinical mastitis in 4 regions of Ningxia were used for the isolation and identification of pathogens according to phenotypic and molecular characteristics. Antimicrobial susceptibility against 22 antimicrobial agents was determined by disk diffusion. The presence of 8 virulence genes in Staph. aureus isolates was tested by PCR. Genotypes of isolates were investigated based on RAPD. Results showed that 35 isolates obtained from mastitis milk samples were identified as Staph. aureus. The isolates were resistant to sulfamethoxazole (100%), penicillin G (94.3%), ampicillin (94.3%), erythromycin (68.6%), azithromycin (68.6%), clindamycin (25.7%), amoxicillin (11.4%), and tetracycline (5.7%). All of the isolates contained one or more virulence genes with average (standard deviation) of 6.6±1.6. The most prevalent virulence genes were hlb (97.1%), followed by fnbpA, hla, coa (94.3% each), nuc (85.7%), fnbpB (80%), clfA (77.1%), and tsst-1 (40%). Nine different gene patterns were found and 3 of them were the dominant gene combinations (77.1%). Staphylococcus aureus isolates (n=35) were divided into 6 genotypes by RAPD tying, the genotypes III and VI were the most prevalent genotypes. There was greatvariation in genotypes of Staph. aureus isolates, not only among different farms, but also within the same herd in Ningxia province. The study showed a high incidence of Staph. aureus with genomic variation of resistance genes, which is matter of great concern in public and animal health in Ningxia province of China. Copyright © 2016 American

  9. The effect of antibody on the adherence of Staphylococcus aureus to bovine mammary epithelial cells

    International Nuclear Information System (INIS)

    Olmsted, S.B.

    1989-01-01

    The ability of S. aureus to adhere to epithelial cells in the ductuals and alveoli of the gland is believed to add greatly to its virulence and may be necessary for colonization. Two in vitro methods were developed for the purpose of quantifying adherence. Both methods utilize bovine mammary epithelial primary cells as targets for labeled bacteria. In one assay, the bacterial are labeled with [methyl- 3 H] thymidine, and incubated on the primary epithelial monolayers. Adherence of the bacterial sample is expressed as the percent radioactivity in the adherent fraction of the total radioactivity in both fractions. The second assay involves labeling the bacteria with biotin. An enzyme-linked immunosorbent assay (ELISA) is then performed with strepavidin conjugated to horseradish peroxidase. Both methods have proven to be reliable, and allow for the testing of many criteria in one assay

  10. Contribution of sortase SrtA2 to Lactobacillus casei BL23 inhibition of Staphylococcus aureus internalization into bovine mammary epithelial cells.

    Directory of Open Access Journals (Sweden)

    Renata F S Souza

    Full Text Available Probiotics have been considered as a promising strategy to prevent various diseases in both humans and animals. This approach has gained interest in recent years as a potential means to control bovine mastitis. In a previous study, we found that several L. casei strains, including BL23, were able to inhibit the internalization of S. aureus, a major etiologic agent of mastitis, into bovine mammary epithelial cells (bMEC. This antagonism required a direct contact between L. casei and bMEC or S. aureus, suggesting the inhibition relied on interactions between L. casei cell surface components and bMEC. In this study, we have investigated the impact of some candidates which likely influence bacteria host cell interactions. We have shown that L. casei BL23 fbpA retained its inhibitory potential, indicating that L. casei BL23 antagonism did not rely (solely on competition between S. aureus and L. casei fibronectin-binding proteins for adhesion to bMEC. We have then investigated the impact of four sortase mutants, srtA1, srtA2, srtC1 and srtC2, and a double mutant (srtA1-srtA2 on L. casei BL23 inhibitory potential. Sortases are responsible for the anchoring on the bacterial cell wall of LPXTG-proteins, which reportedly play an important role in bacteria-host cell interaction. All the srt mutants tested presented a reduced inhibition capacity, the most pronounced effect being observed with the srtA2 mutant. A lower internalization capacity of L. casei srtA2 into bMEC was also observed. This was associated with several changes at the surface of L. casei BL23 srtA2 compared to the wild type (wt strain, including altered abundance of some LPXTG- and moonlighting proteins, and modifications of cell wall structure. These results strongly support the role of sortase A2 in L. casei BL23 inhibition against S. aureus internalization. Deciphering the contribution of the cell surface components altered in srtA2 strain in the inhibition will require further

  11. Melittin and its potential in the destruction and inhibition of the biofilm formation by Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa isolated from bovine milk.

    Science.gov (United States)

    Picoli, Tony; Peter, Cristina Mendes; Zani, João Luíz; Waller, Stefanie Bressan; Lopes, Matheus Gomes; Boesche, Kamilla Neutzling; Vargas, Gilberto D Ávila; Hübner, Silvia de Oliveira; Fischer, Geferson

    2017-11-01

    Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa stand out in veterinary and human medicine for their role in opportunistic infections and their pathogenic mechanisms, including the biofilms formation. It was investigated the antibacterial activity of melittin and antibiofilm of such bacteria. Twelve strains of these microorganisms isolated from bovine milk were used, as well as the strains S. aureus ATCC 12600, E. coli ATCC 8739 and Pseudomonas aeruginosa ATCC 15442. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) were determined by broth microdilution technique. The biofilms were formed in 96-well plates and melittin on these colonies was added at different concentrations and times. Bacteria previously exposed to melittin were evaluated for inhibition of biofilm production. The MIC and MBC were respectively in μg/mL: S. aureus (6-7 and 32-64), E. coli (40-42.5 and 64-128) and P. aeruginosa (65-70 and 64-128). S. aureus biofilms were more sensitive to the action of melittin, since upon exposure to a concentration 10 times lower than the MIC for 4 h, was completely destroyed. In Gram negative bacteria, the pre-formed biofilm was destroyed only when exposed for 4 h under the MIC. With respect to inhibition of biofilm production, S. aureus was the most sensitive again because produced only 37.2% of the biofilm formed by the control (without previous exposure to melittin), when exposed to the MIC, and at a concentration hundred times smaller than MIC, this microorganism produced 75.2% of the biofilm. E. coli was the most resistant bacteria and produced 56.3% of the biofilm, even if previously exposed to melittin MIC. Melittin presents desirable effects in combating microorganisms studied both at your disposal, biofilm destruction and inhibition of the formation, and maybe used in future studies of new strategies to combat infections caused by these pathogens. Copyright © 2017 Elsevier Ltd. All

  12. Latent class analysis of the diagnostic characteristics of PCR and conventional bacteriological culture in diagnosing intramammary infections caused by Staphylococcus aureus in dairy cows at dry off

    DEFF Research Database (Denmark)

    Cederlöf, Sara Ellinor; Toft, Nils; Aalbæk, Bent

    2012-01-01

    characteristics of PathoProof TM Mastitis PCR Assay and bacteriological culture (BC) in diagnosing bovine intramammary infections caused by S. aureus at dry off at different PCR cycle threshold (Ct)-value cut-offs. METHODS: Sterile quarter samples and non-sterile composite samples from 140 animals in seven herds...... were collected in connection with the dairy herd improvement (DHI) milk recording. All quarter samples were analyzed using BC whereas all composite samples were analyzed with PathoProof TM Mastitis PCR Assay. Latent class analysis was used to estimate test properties for PCR and BC in the absence...

  13. The Lytic SA Phage Demonstrate Bactericidal Activity against Mastitis Causing Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Hamza Ameer

    2016-01-01

    Full Text Available Staphylococcus aureus is the major causative agent of mastitis among dairy animals as it causes intramammary gland infection. Due to antibiotic resistance and contamination of antibiotics in the milk of diseased animals; alternative therapeutic agents are required to cure mastitis. Lytic bacteriophages and their gene products can be potential therapeutic agents against bacteria as they are host specific and less harmful than antibiotics. In this study, Staphylococcus aureus were isolated from milk samples of the infected animals and identified biochemically. SA phage was isolated from sewage water showing lytic activity against Staphylococcus aureus isolates. The highest lytic activity of bacteriophages was observed at 37°C and pH 7, and the most suitable storage condition was at 4°C. SA phage efficiently reduced bacterial growth in the bacterial reduction assay. The characterization and bacterial growth reduction activity of the bacteriophages against Staphylococcus aureus signifies their underlying potential of phage therapy against mastitis.

  14. Genetic Variation among Staphylococcus aureus Strains from Norwegian Bulk Milk

    Science.gov (United States)

    Jørgensen, H. J.; Mørk, T.; Caugant, D. A.; Kearns, A.; Rørvik, L. M.

    2005-01-01

    Strains of Staphylococcus aureus obtained from bovine (n = 117) and caprine (n = 114) bulk milk were characterized and compared with S. aureus strains from raw-milk products (n = 27), bovine mastitis specimens (n = 9), and human blood cultures (n = 39). All isolates were typed by pulsed-field gel electrophoresis (PFGE). In addition, subsets of isolates were characterized using multilocus sequence typing (MLST), multiplex PCR (m-PCR) for genes encoding nine of the staphylococcal enterotoxins (SE), and the cloverleaf method for penicillin resistance. A variety of genotypes were observed, and greater genetic diversity was found among bovine than caprine bulk milk isolates. Certain genotypes, with a wide geographic distribution, were common to bovine and caprine bulk milk and may represent ruminant-specialized S. aureus. Isolates with genotypes indistinguishable from those of strains from ruminant mastitis were frequently found in bulk milk, and strains with genotypes indistinguishable from those from bulk milk were observed in raw-milk products. This indicates that S. aureus from infected udders may contaminate bulk milk and, subsequently, raw-milk products. Human blood culture isolates were diverse and differed from isolates from other sources. Genotyping by PFGE, MLST, and m-PCR for SE genes largely corresponded. In general, isolates with indistinguishable PFGE banding patterns had the same SE gene profile and isolates with identical SE gene profiles were placed together in PFGE clusters. Phylogenetic analyses agreed with the division of MLST sequence types into clonal complexes, and isolates within the same clonal complex had the same SE gene profile. Furthermore, isolates within PFGE clusters generally belonged to the same clonal complex. PMID:16332822

  15. Staphylococcus aureus seroproteomes discriminate ruminant isolates causing mild or severe mastitis

    Directory of Open Access Journals (Sweden)

    Le Maréchal Caroline

    2011-02-01

    Full Text Available Abstract Staphylococcus aureus is a major cause of mastitis in ruminants. In ewe mastitis, symptoms range from subclinical to gangrenous mastitis. S. aureus factors or host-factors contributing to the different outcomes are not completely elucidated. In this study, experimental mastitis was induced on primiparous ewes using two S. aureus strains, isolated from gangrenous (strain O11 or subclinical (strain O46 mastitis. Strains induced drastically distinct clinical symptoms when tested in ewe and mice experimental mastitis. Notably, they reproduced mild (O46 or severe (O11 mastitis in ewes. Ewe sera were used to identify staphylococcal immunoreactive proteins commonly or differentially produced during infections of variable severity and to define core and accessory seroproteomes. Such SERological Proteome Analysis (SERPA allowed the identification of 89 immunoreactive proteins, of which only 52 (58.4% were previously identified as immunogenic proteins in other staphylococcal infections. Among the 89 proteins identified, 74 appear to constitute the core seroproteome. Among the 15 remaining proteins defining the accessory seroproteome, 12 were specific for strain O11, 3 were specific for O46. Distribution of one protein specific for each mastitis severity was investigated in ten other strains isolated from subclinical or clinical mastitis. We report here for the first time the identification of staphylococcal immunogenic proteins common or specific to S. aureus strains responsible for mild or severe mastitis. These findings open avenues in S. aureus mastitis studies as some of these proteins, expressed in vivo, are likely to account for the success of S. aureus as a pathogen of the ruminant mammary gland.

  16. Exchange of adsorbed serum proteins during adhesion of Staphylococcus aureus to an abiotic surface and Candida albicans hyphae--an AFM study.

    Science.gov (United States)

    Ovchinnikova, Ekaterina S; van der Mei, Henny C; Krom, Bastiaan P; Busscher, Henk J

    2013-10-01

    Staphylococcus aureus and Candida albicans are the second and third most commonly isolated microorganisms in hospital-related-infections, that are often multi-species in nature causing high morbidity and mortality. Here, adhesion forces between a S. aureus strain and abiotic (tissue-culture-polystyrene, TCPS) or partly biotic (TCPS with adhering hyphae of C. albicans) surfaces were investigated in presence of fetal-bovine-serum or individual serum proteins and related with staphylococcal adhesion. Atomic-force-microscopy was used to measure adhesion forces between S. aureus and the abiotic and biotic surfaces. Adsorption of individual serum proteins like albumin and apo-transferrin to abiotic TCPS surfaces during 60min, impeded development of strong adhesion forces as compared to fibronectin, while 60min adsorption of proteins from fetal-bovine-serum yielded a decrease in adhesion force from -5.7nN in phosphate-buffered-saline to -0.6nN. Adsorption of albumin and apo-transferrin also decreased staphylococcal adhesion forces to hyphae as compared with fibronectin. During 60min exposure to fetal-bovine-serum however, initial (5min protein adsorption) staphylococcal adhesion forces were low (-1.6nN), but strong adhesion forces of around -5.5nN were restored within 60min. This suggests for the first time that in whole fetal-bovine-serum exchange of non-adhesive proteins by fibronectin occurs on biotic C. albicans hyphal surfaces. No evidence was found for such protein exchange on abiotic TCPS surfaces. Staphylococcal adhesion of abiotic and biotic surfaces varied in line with the adhesion forces and was low on TCPS in presence of fetal-bovine-serum. On partly biotic TCPS, staphylococci aggregated in presence of fetal-bovine-serum around adhering C. albicans hyphae. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Capsular polysaccharide typing of domestic mastitis-causing Staphylococcus aureus strains and its potential exploration of bovine mastitis vaccine development. I. Capsular polysaccharide typing, isolation and purification of the strains.

    Science.gov (United States)

    Han, H R; Pak, S I; Kang, S W; Jong, W S; Youn, C J

    2000-06-01

    One hundred seven isolates of Staphylococcus aureus from bovine mastitis were investigated for colony morphology in serum-soft agar (SSA), autoagglutination in salt, and capsular serotype. Capsular polysaccharide (CP) was purified and quantified from the extracts of clinical isolates. Overall, 89 isolates (83.2%) were diffuse in the SSA, without any difference in the proportion of diffuse colony between type 5 and type 8 strains. Some strains exhibited compact colonies in the SSA and expressed CP as determined by an enzyme-linked immunosorbent assay, indicating that compact morphology does not exclude encapsulation. The majority of the strains (11/12) showed autoagglutination in the salt aggregation test. The serotype 336 accounted for 46.7% of the isolates followed by serotype 5 (12.1%) and serotype 8 (12.1%). Particularly, twenty-six (24.3%) isolates reacted with two serotypes; 7 for type 8/336 and 19 for type 5/336. Five isolates (4.7%) were nontypeable with monoclonal antibodies specific for CP serotype 5, 8, or 336. The CP concentration in culture supernatants varied with the serotypes, and the total amount of CP produced by cells grown in a liquid medium was much less than that produced by cells grown on a solid medium. The Western blotting indicated that the CP bands of S. aureus serotype 5 and 8 were ranged in the molecular mass of 58-84 kilodalton (kDa), with additional bands in the region of approximately >/= 48 or

  18. Staphylococcus aureus biofilm removal by targeting biofilm-associated extracellular proteins

    Directory of Open Access Journals (Sweden)

    Sudhir K Shukla

    2017-01-01

    Methods: Biofilm assay was done in 96-well microtitre plate to evaluate the effect of proteinase K on biofilms of bovine mastitis S. Aureus isolates. Extracellular polymeric substances were extracted and evaluated for their composition (protein, polysaccharides and extracellular DNA, before and after the proteinase K treatment. Results: Biofilm assay showed that 2 μg/ml proteinase K significantly inhibited biofilm development in bap-positive S. aureus V329 as well as other S. aureus isolates (SA7, SA10, SA33, SA352, but not in bap-mutant M556 and SA392 (a weak biofilm-producing strain. Proteinase K treatment on S. aureus planktonic cells showed that there was no inhibition of planktonic growth up to 32 μg/ml of proteinase K. Proteinase K treatment on 24 h old preformed biofilms showed an enhanced dispersion of bap-positive V329 and SA7, SA10, SA33 and SA352 biofilms; however, proteinase K did not affect the bap-mutant S. aureus M556 and SA392 biofilms. Biofilm compositions study before and after proteinase K treatment indicated that Bap might also be involved in eDNA retention in the biofilm matrix that aids in biofilm stability. When proteinase K was used in combination with antibiotics, a synergistic effect in antibiotic efficacy was observed against all biofilm-forming S. aureus isolates. Interpretation & conclusions: Proteinase K inhibited biofilms growth in S. aureus bovine mastitis isolates but did not affect their planktonic growth. An enhanced dispersion of preformed S. aureus biofilms was observed on proteinase K treatment. Proteinase K treatment with antibiotics showed a synergistic effect against S. aureus biofilms. The study suggests that dispersing S. aureus by protease can be of use while devising strategies againstS. aureus biofilms.

  19. Antibiotic activity of the extract of Punica granatum Linn. over bovine strains of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Maria A. R. Silva

    Full Text Available Human and veterinary medicines have not been so well succeeded in order to achieving their goals concerning the treatment of infections for long term caused by Staphylococcus aureus linked to resistance development against antibiotic agents. The antibiotic activity of the Punica granatum Linn. fresh fruit pericarp extract was evaluated by the agar diffusion method on 38 S. aureus strains, isolated from apparently healthy lactating cows in farms situated in counties of the semi-arid region of the State of Paraíba, Brazil to determine the minimum inhibitory concentration (MIC. Twenty-two of the thirty-eight strains are penicillin-resistant (PRSA. The extract of P. granatum presented potential antibiotic action over all the assayed strains, forming 10 to 36 mm diameter inhibition zones. This paper's results claim the effectiveness of the extract of P. granatum as a potential antibacterial agent on S. aureus, and display the significance of evaluating new substances with antimicrobial potential, which can contribute to alternative therapeutics for veterinary and medicine.

  20. Effect of essential oils of Syzygium aromaticum and Cinnamomum zeylanicum and their major components on biofilm production in Staphylococcus aureus strains isolated from milk of cows with mastitis.

    OpenAIRE

    Budri, Paulo E; Silva, Nathalia CC; Bonsaglia, Erika CR; Fernandes Júnior, Ary; Araújo Júnior, Joao P; Doyama, Julio T; Gonçalves, Juliano L; Santos, M V; Fitzgerald-Hughes, Deirdre; Rall, Vera LM

    2015-01-01

    Bovine mastitis is an inflammation of the mammary glands of cows and causes significant economic losses in dairy cattle. Staphylococcus aureus is one of the microorganisms most commonly isolated. Novel agents are required in agricultural industries to prevent the development of mastitis. The production of biofilm by Staph. aureus facilitates the adhesion of bacteria to solid surfaces and contributes to the transmission and maintenance of these bacteria. The effect of the essential oils of Syz...

  1. Bovine-associated CNS species resist phagocytosis differently

    Science.gov (United States)

    2013-01-01

    Background Coagulase-negative staphylococci (CNS) cause usually subclinical or mild clinical bovine mastitis, which often remains persistent. Symptoms are usually mild, mostly only comprising slight changes in the appearance of milk and possibly slight swelling. However, clinical mastitis with severe signs has also been reported. The reasons for the differences in clinical expression are largely unknown. Macrophages play an important role in the innate immunity of the udder. This study examined phagocytosis and killing by mouse macrophage cells of three CNS species: Staphylococcus chromogenes (15 isolates), Staphylococcus agnetis (6 isolates) and Staphylococcus simulans (15 isolates). Staphylococcus aureus (7 isolates) was also included as a control. Results All the studied CNS species were phagocytosed by macrophages, but S. simulans resisted phagocytosis more effectively than the other CNS species. Only S. chromogenes was substantially killed by macrophages. Significant variations between isolates were seen in both phagocytosis and killing by macrophages and were more common in the killing assays. Significant differences between single CNS species and S. aureus were observed in both assays. Conclusion This study demonstrated that differences in the phagocytosis and killing of mastitis-causing staphylococci by macrophages exist at both the species and isolate level. PMID:24207012

  2. Neutrophil depletion causes a fatal defect in murine pulmonary Staphylococcus aureus clearance.

    Science.gov (United States)

    Robertson, Charles M; Perrone, Erin E; McConnell, Kevin W; Dunne, W Michael; Boody, Barrett; Brahmbhatt, Tejal; Diacovo, M Julia; Van Rooijen, Nico; Hogue, Lisa A; Cannon, Carolyn L; Buchman, Timothy G; Hotchkiss, Richard S; Coopersmith, Craig M

    2008-12-01

    Staphylococcus aureus is the most common cause of healthcare-associated pneumonia. Despite the significant morbidity and mortality associated with the disease, animal models of S. aureus pneumonia are rare. We examined the pathogenicity of four different strains of S. aureus (both methicillin-sensitive and -resistant as well as Panton-Valentine leukocidin-positive and -negative) in four strains of immunocompetent inbred and outbred mice (FVB/N, C57Bl/6, BALB/c, ND4; n = 148). The immunological basis for the development of murine S. aureus pneumonia was then determined by selectively depleting neutrophils, lymphocytes, or pulmonary macrophages prior to the onset of infection. An additional cohort of animals was rendered immunosuppressed by induction of abdominal sepsis via cecal ligation and puncture 2, 4, or 7 d prior to the onset of pneumonia. Nearly all immunocompetent mice survived, regardless of which strain of S. aureus was used or which strain of mouse was infected. Among animals with immune depletion or prior immunosuppression, survival was decreased only following neutrophil depletion (26% versus 90% alive at 7 d, P < 0.0001). Compared to immunocompetent animals, neutrophil-depleted mice with S. aureus pneumonia had delayed pulmonary bacterial clearance at 16 and 40 h but had no difference in levels of bacteremia. Neutrophil-depleted mice also had elevated levels of pulmonary monocyte chemotactic protein-1 (822 pg/mL versus 150 pg/mL, P < 0.05). In contrast, pulmonary histological appearance was similar in both groups as was dry/wet lung weight. These results suggest that neutrophils play a critical role in the host response to S. aureus pneumonia, and the survival differences observed in neutrophil-depleted mice are associated with alterations in bacterial clearance and pulmonary cytokine response.

  3. Methicillin-resistant Staphylococcus aureus of lineage ST398 as cause of mastitis in cows.

    Science.gov (United States)

    Silva, N C C; Guimarães, F F; Manzi, M P; Júnior, A Fernandes; Gómez-Sanz, E; Gómez, P; Langoni, H; Rall, V L M; Torres, C

    2014-12-01

    The objective of this study was to analyse the prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) in milk of cows with mastitis. The California mastitis test (CMT) was used to detect the presence of mastitis in all 100 cows of a farm in Brazil. The CMT was positive in milk of 115 mammary quarters from 36 cows (36%). MRSA isolates were recovered from 4 of these 36 cows with mastitis (11%), and they were further characterized (one MRSA/sample). The four MRSA isolates were typed as t011-ST398-agr1-SCCmecV and presented two different pulsed-field-gel-electrophoresis-ApaI patterns. These four MRSA isolates showed resistance to tetracycline, streptomycin and ciprofloxacin, carried the mecA, blaZ, tet(K), and tet(M) resistance genes, and presented the S84L and S80F amino acid substitutions in GyrA and GrlA proteins, respectively. Two ST398 isolates exhibited resistance to gentamicin and tobramycin [with aac(6)-aph(2") and ant(4)-Ia genes] and one isolate resistance to clindamycin [with lnu(B) and lsa(E) genes]; this latter isolate also carried the spectinomycin/streptomycin resistance genes spw and aadE. MRSA of lineage ST398 is worldwide spread, normally multidrug resistant and may be responsible for bovine mastitis. To our knowledge, this is the first detection of MRSA-ST398 in Brazil. Few studies on the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) from bovine isolates have been performed in Brazil. MRSA of lineage ST398 is worldwide spread and associated with farm animals. Multidrug-resistant MRSA-ST398 isolates were recovered in 11% of mastitic cows from a single farm, with one isolate carrying the unusual lsa(E), spw and aadE genes. To our knowledge, this is the first detection of MRSA-ST398 isolates in milk samples of cows with mastitis in Brazil. © 2014 The Society for Applied Microbiology.

  4. The major bovine mastitis pathogens have different cell tropisms in cultures of bovine mammary gland cells

    NARCIS (Netherlands)

    Lammers, A.; Vorstenbosch, van C.J.; Erkens, J.H.F.; Smith, H.E.

    2001-01-01

    We previously showed that Staphylococcus aureus cells adhered mainly to an elongated cell type, present in cultures of bovine mammary gland cells. Moreover. we showed that this adhesion was mediated by binding to fibronectin. The same in vitro model was used here, to study adhesion of other

  5. In Vitro Antimicrobial Activity of Plant-Derived Diterpenes against Bovine Mastitis Bacteria

    Directory of Open Access Journals (Sweden)

    Rodrigo C. S. Veneziani

    2013-07-01

    Full Text Available We evaluated the antibacterial activity of three diterpenes isolated from natural sources against a panel of microorganisms responsible for bovine mastitis. ent-Copalic acid (CA was the most active metabolite, with promising MIC values (from 1.56 to 6.25 µg mL−1 against Staphylococcus aureus (ATCC and clinical isolate, Staphylococcus epidermidis, Streptococcus agalactiae, and Streptococcus dysgalactiae. We conducted time-kill assays of CA against S. aureus, a commensal organism considered to be a ubiquitous etiological agent of bovine mastitis in dairy farms worldwide. In the first 12 h, CA only inhibited the growth of the inoculums (bacteriostatic effect, but its bactericidal effect was clearly noted thereafter (between 12 and 24 h. In conclusion, CA should be considered for the control of several Gram-positive bacteria related to bovine mastitis.

  6. Communications of Staphylococcus aureus and non-aureus Staphylococcus species from bovine intramammary infections and teat apex colonization

    DEFF Research Database (Denmark)

    Mahmmod, Yasser S.; Klaas, Ilka Christine; Svennesen, Line

    2018-01-01

    The role of non-aureus staphylococci (NAS) in the risk of acquisition of intramammary infections with Staphylococcus aureus is vague and still under debate. The objectives of this study were to (1) investigate the distribution patterns of NAS species from milk and teat skin in dairy herds with au...

  7. Geographic distribution of Staphylococcus aureus causing invasive infections in Europe : A molecular-epidemiological analysis

    NARCIS (Netherlands)

    Grundmann, Hajo; Aanensen, David M; van den Wijngaard, Cees C; Spratt, Brian G; Harmsen, Dag; Friedrich, Alexander W; Tami, Adriana

    Background: Staphylococcus aureus is one of the most important human pathogens and methicillin-resistant variants (MRSAs) are a major cause of hospital and community-acquired infection. We aimed to map the geographic distribution of the dominant clones that cause invasive infections in Europe.

  8. Identification of virulence factors in 16S-23S rRNA intergenic spacer genotyped Staphylococcus aureus isolated from water buffaloes and small ruminants.

    Science.gov (United States)

    Cremonesi, P; Zottola, T; Locatelli, C; Pollera, C; Castiglioni, B; Scaccabarozzi, L; Moroni, P

    2013-01-01

    Staphylococcus aureus is an important human and animal pathogen, and is regarded as an important cause of intramammary infection (IMI) in ruminants. Staphylococcus aureus genetic variability and virulence factors have been well studied in veterinary medicine, especially in cows as support for control and management of IMI. The aim of the present study was to genotype 71 Staph. aureus isolates from the bulk tank and foremilk of water buffaloes (n=40) and from udder tissue (n=7) and foremilk (n=24) from small ruminants. The method used was previously applied to bovine Staph. aureus and is based on the amplification of the 16S-23S rRNA intergenic spacer region. The technique applied was able to identify different Staph. aureus genotypes isolated from dairy species other than the bovine species, and cluster the genotypes according to species and herds. Virulence gene distribution was consistent with genotype differentiation. The isolates were also characterized through determination of the presence of 19 virulence-associated genes by specific PCR. Enterotoxins A, C, D, G, I, J, and L were associated with Staph. aureus isolates from buffaloes, whereas enterotoxins C and L were linked to small ruminants. Genes coding for methicillin resistance, Panton-Valentine leukocidin, exfoliative toxins A and B, and enterotoxins B, E, and H were undetected. These findings indicate that RNA template-specific PCR is a valid technique for typing Staph. aureus from buffaloes and small ruminants and is a useful tool for understanding udder infection epidemiology. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  9. Characterization of a vraG Mutant in a Genetically Stable Staphylococcus aureus Small-Colony Variant and Preliminary Assessment for Use as a Live-Attenuated Vaccine against Intrammamary Infections.

    Directory of Open Access Journals (Sweden)

    Julie Côté-Gravel

    Full Text Available Staphylococcus aureus is a leading cause of bovine intramammary infections (IMIs that can evolve into difficult-to-treat chronic mastitis. To date, no vaccine formulation has shown high protective efficacy against S. aureus IMI, partly because this bacterium can efficiently evade the immune system. For instance, S. aureus small colony variants (SCVs have intracellular abilities and can persist without producing invasive infections. As a first step towards the development of a live vaccine, this study describes the elaboration of a novel attenuated mutant of S. aureus taking advantage of the SCV phenotype. A genetically stable SCV was created through the deletion of the hemB gene, impairing its ability to adapt and revert to the invasive phenotype. Further attenuation was obtained through inactivation of gene vraG (SACOL0720 which we previously showed to be important for full virulence during bovine IMIs. After infection of bovine mammary epithelial cells (MAC-T, the double mutant (ΔvraGΔhemB was less internalized and caused less cell destruction than that seen with ΔhemB and ΔvraG, respectively. In a murine IMI model, the ΔvraGΔhemB mutant was strongly attenuated, with a reduction of viable counts of up to 5-log10 CFU/g of mammary gland when compared to the parental strain. A complete clearance of ΔvraGΔhemB from glands was observed whereas mortality rapidly (48h occurred with the wild-type strain. Immunization of mice using subcutaneous injections of live ΔvraGΔhemB raised a strong immune response as judged by the high total IgG titers measured against bacterial cell extracts and by the high IgG2a/IgG1 ratio observed against the IsdH protein. Also, ΔvraGΔhemB had sufficient common features with bovine mastitis strains so that the antibody response also strongly recognized strains from a variety of mastitis associated spa types. This double mutant could serve as a live-attenuated component in vaccines to improve cell-mediated immune

  10. Bactericidal and Anti-biofilm Effects of Polyhexamethylene Biguanide in Models of Intracellular and Biofilm of Staphylococcus aureus Isolated from Bovine Mastitis

    Directory of Open Access Journals (Sweden)

    Nor F. Kamaruzzaman

    2017-08-01

    Full Text Available Staphylococcus aureus infection is a common cause of mastitis, reducing milk yield, affecting animal welfare and causing huge economic losses within the dairy industry. In addition to the problem of acquired drug resistance, bacterial invasion into udder cells and the formation of surface biofilms are believed to reduce antibiotic efficacy, leading to treatment failure. Here, we investigated the antimicrobial activities of enrofloxacin, an antibiotic that is commonly used in mastitis therapy and polyhexamethylene biguanide (PHMB, an antimicrobial polymer. The antimicrobial activities were tested against intracellular S. aureus in infected Mac-T cells (host cells. Also, fluorescein-tagged PHMB was used to study PHMB uptake and localization with S. aureus within the infected Mac-T cells. Anti-biofilm activities were tested by treating S. aureus biofilms and measuring effects on biofilm mass in vitro. Enrofloxacin and PHMB at 15 mg/L killed between 42 to 92 and 99.9% of intracellular S. aureus, respectively. PHMB-FITC entered and colocalized with the intracellular S. aureus, suggesting direct interaction of the drug with the bacteria inside the host cells. Enrofloxacin and PHMB at 15 mg/L reduced between 10 to 27% and 28 to 37% of biofilms’ mass, respectively. The half-maximal inhibitory concentrations (IC50 obtained from a cytotoxicity assay were 345 ± 91 and 21 ± 2 mg/L for enrofloxacin and PHMB, respectively; therefore, both compounds were tolerated by the host cells at high concentrations. These findings suggest that both antimicrobials are effective against intracellular S. aureus and can disrupt biofilm structures, with PHMB being more potent against intracellular S. aureus, highlighting the potential application of PHMB in mastitis therapy.

  11. Communications of Staphylococcus aureus and non-aureus Staphylococcus species from bovine intramammary infections and teat apex colonization.

    Science.gov (United States)

    Mahmmod, Yasser S; Klaas, Ilka Christine; Svennesen, Line; Pedersen, Karl; Ingmer, Hanne

    2018-05-16

    The role of non-aureus staphylococci (NAS) in the risk of acquisition of intramammary infections with Staphylococcus aureus is vague and still under debate. The objectives of this study were to (1) investigate the distribution patterns of NAS species from milk and teat skin in dairy herds with automatic milking systems, and (2) examine if the isolated NAS influences the expression of S. aureus virulence factors controlled by the accessory gene regulator (agr) quorum sensing system. In 8 herds, 14 to 20 cows with elevated somatic cell count were randomly selected for teat skin swabbing and aseptic quarter foremilk samples from right hind and left front quarters. Teat skin swabs were collected using the modified wet-dry method and milk samples were taken aseptically for bacterial culture. Colonies from quarters with suspicion of having NAS in milk or teat skin samples (or both) were subjected to MALDI-TOF assay for species identification. To investigate the interaction between S. aureus and NAS, 81 isolates NAS were subjected to a qualitative β-galactosidase reporter plate assay. In total, 373 NAS isolates were identified representing 105 from milk and 268 from teat skin of 284 quarters (= 142 cows). Sixteen different NAS species were identified, 15 species from teat skin and 10 species from milk. The most prevalent NAS species identified from milk were Staphylococcus epidermidis (50%), Staphylococcus haemolyticus (15%), and Staphylococcus chromogenes (11%), accounting for 76%. Meanwhile, the most prevalent NAS species from teat skin were Staphylococcus equorum (43%), S. haemolyticus (16%), and Staphylococcus cohnii (14%), accounting for 73%. Using reporter gene fusions monitoring transcriptional activity of key virulence factors and regulators, we found that out of 81 supernatants of NAS isolates, 77% reduced expression of hla, encoding a-hemolysin, 70% reduced expression of RNAIII, the key effector molecule of agr, and 61% reduced expression of spa encoding

  12. Occurrence of bovine mastitis and isolation of Staphyloccocus ...

    African Journals Online (AJOL)

    Occurrence of bovine mastitis and isolation of Staphyloccocus species from ... the samples that were positive for CMT were found to be culture positive and out of ... S. aureus and 12.3% (12/97) were coagulase-negative staphylococci (CONS).

  13. Characterization and complete genome sequence analysis of a novel virulent Siphoviridae phage against Staphylococcus aureus isolated from bovine mastitis in Xinjiang, China.

    Science.gov (United States)

    Zhang, Qian; Xing, Shaozhen; Sun, Qiang; Pei, Guangqian; Cheng, Shi; Liu, Yannan; An, Xiaoping; Zhang, Xianglilan; Qu, Yonggang; Tong, Yigang

    2017-06-01

    Bovine mastitis is one of the most costly diseases in dairy cows worldwide. It can be caused by over 150 different microorganisms, where Staphylococcus aureus is the most frequently isolated and a major pathogen responsible for heavy economic losses in dairy industry. Although antibiotic therapy is most widely used, alternative treatments are necessary due to the increasing antibiotic resistance. Using phage for pathogen control is a promising tool in the fight against antibiotic resistance. Mainly using high-throughput sequencing, bioinformatics and our proposed phage termini identification method, we have isolated and characterized a novel virulent phage, designated as vB_SauS_IMEP5, from manure collected from dairy farms in Shihezi, Xinjiang, China, for use as a biocontrol agent against Staphylococcus aureus infections. Its latent period was about 30 min and its burst size was approximately 272PFU/cell. Phage vB_SauS_IMEP5 survives in a wide pH range between 3 and 12. A treatment at 70 °C for 20 min can inactive the phage. Morphological analysis of vB_SauS_IMEP5 revealed that phage vB_SauS_IMEP5 morphologically resembles phages in the family Siphoviridae. Among our tested multiplicity of infections (MOIs), the optimal multiplicity of infection (MOI) of this phage was determined to be 0.001, suggesting that phage vB_SauS_IMEP5 has high bacteriolytic potential and good efficiency for reducing bacterial growth. The complete genome of IME-P5 is a 44,677-bp, linear, double-stranded DNA, with a G+C content of 34.26%, containing 69 putative ORFs. The termini of genome were determined with next-generation sequencing data using our previously proposed termini identification method, which suggests that this phage has non-redundant termini with 9nt 3' protruding cohesive ends. The genomic and proteomic characteristics of IMEP5 demonstrate that this phage does not belong to any of the previously recognized Siphoviridae Staphylococcus phage groups, suggesting the

  14. Microarray based study on virulence-associated genes and resistance determinants of Staphylococcus aureus isolates from cattle.

    Science.gov (United States)

    Monecke, Stefan; Kuhnert, Peter; Hotzel, Helmut; Slickers, Peter; Ehricht, Ralf

    2007-11-15

    Staphylococcus aureus is a common pathogen which can colonise and infect not only man, but also domestic animals. Especially, infection of cattle is of high economic relevance as S. aureus is an important causal agent of bovine mastitis. In the present contribution, a DNA microarray was applied for the study of 144 different gene targets, including resistance genes and genes encoding exotoxins, in S. aureus isolated from cows. One hundred and twenty-eight isolates from Germany and Switzerland were tested. These isolates were assigned to 20 different strains and nine clonal complexes. The majority of isolates belonged either to apparently closely related clonal complexes 8, 25, and 97 (together 34.4%) or were related to the sequenced bovine strain RF122 (48.4%). Notable characteristics of S. aureus of bovine origin are the carriage of intact haemolysin beta (in 82% of isolates tested), the absence of staphylokinase (in 89.1%), the presence of allelic variants of several exotoxins such as toxic shock syndrome toxin and enterotoxin N, and the occurrence of the leukocidin lukF-P83/lukM (in 53.1%). Two isolates were methicillin-resistant S. aureus (MRSA). One of them was a clonal complex 8 MRSA related to the epidemic MRSA strain Irish 01. The other one belonged to ST398/spa-type 34 resembling a newly emerging MRSA strain which has been described to occur in humans as well as in domestic animals. The presence of these two strains highlights the possibility of transfers of S. aureus strains between different host species.

  15. Root cause analysis of methicillin resistant Staphylococcus aureus bacteraemia.

    Science.gov (United States)

    Aslam, Nadia; Mehdi, Naima; Izhar, Mateen

    2015-10-01

    To find the important risk factors and sources of bacteraemia in patients suffering from methicillin-resistant staphylococcus aureus bacteraemia. The descriptive study was carried out at Shaikh Zayed Hospital, Lahore, from October 2010 to August 2011. Blood cultures were processed to isolate methicillin-resistant staphylococcus aureus. A questionnaire was completed by the participating patients suffering from bacteraemia. Information about risk factors present at the time and risk factors that served as the source of bacteraemia were noted. Total 4058 blood cultures were processed and 669(16.5%) were positive. Of them, 194(29%) cultures were found to be positive for staphylococci. Out of these 194 blood cultures, coagulase-negative staphylococci were isolated from 117(60%), and 77(40%) were positive for S. aureus. Out of these 77 samples, 26(34%) were found to be methicillin-sensitive staphylococcus aureus and 51(66%) were methicillin-resistant staphylococcus aureus. The overall frequency of methicillin-resistant staphylococcus aureus was 1.25%; 7.62% out of positive blood culture; 26.28% out of total staphylococci; and 66% out of total S. aureus. As for the source of infection, central venous pressure line 11(21.6%), post-influenza pneumonia 9(17.6%), peripheral intravenous line 8(15.7%) and dialysis line 7(13.7%) were major reasons. Taking care of aseptic measures while insertion, frequent change and early removal of the central venous and dialysis lines is of critical significance.

  16. In vitro photoinactivation of bovine mastitis related pathogens.

    Science.gov (United States)

    Sellera, Fábio Parra; Sabino, Caetano Padial; Ribeiro, Martha Simões; Gargano, Ronaldo Gomes; Benites, Nilson Roberti; Melville, Priscilla Anne; Pogliani, Fabio Celidonio

    2016-03-01

    Bovine mastitis is considered the most important disease of worldwide dairy industry. Treatment of this disease is based on the application intramammary antibiotic, which favors an increase in the number of resistant bacteria in the last decade. Photodynamic inactivation (PDI) has been investigated in different areas of Health Sciences, and has shown great potential for inactivating different pathogens, without any selection of resistant microorganisms. The objective of this study was to investigate the efficacy of PDI in the inactivation of pathogens associated with bovine mastitis. We tested the effectiveness of PDI against antibiotic resistant strains, isolated from bovine mastitis, from the following species: Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, Corynebacterium bovis, and the alga Prototheca zopfii. Nine experimental groups were evaluated: control, no treatment; light only, irradiation of a red light-emitting diode (λ=662 (20) nm) for 180 s; exposure to 50 μM methylene blue alone for 5 min; and PDI for 5, 10, 30, 60, 120 and 180 s. S. dysgalactiae, S. aureus, and C. bovis were inactivated after 30s of irradiation, whereas S. agalactiae was inactivated after 120 s and P. zopfii at 180 s of irradiation. These results show that PDI can be an interesting tool for inactivating pathogens for bovine mastitis. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Co-infection of methicillin-resistant Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus and extended spectrum β-lactamase producing Escherichia coli in bovine mastitis--three cases reported from India.

    Science.gov (United States)

    Bandyopadhyay, Samiran; Samanta, Indranil; Bhattacharyya, Debaraj; Nanda, Pramod Kumar; Kar, Debasish; Chowdhury, Jayanta; Dandapat, Premanshu; Das, Arun Kumar; Batul, Nayan; Mondal, Bimalendu; Dutta, Tapan Kumar; Das, Gunjan; Das, Bikash Chandra; Naskar, Syamal; Bandyopadhyay, Uttam Kumar; Das, Suresh Chandra; Bandyopadhyay, Subhasish

    2015-03-01

    Emergence of antimicrobial resistance among bovine mastitis pathogens is the major cause of frequent therapeutic failure and a cause of concern for veterinary practitioners. This study describes intra-mammary infection of methicillin-resistant Staphylococcus epidermidis (MRSE), methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum β-lactamase (ESBL) producing Escherichia coli in two Holstein Friesian crossbred cows with subclinical mastitis and one non-descript cow with clinical mastitis in two different districts of West Bengal, India. In total, three MRSE, one MRSA and three ESBL producing E. coli were isolated from these cases. Both the crossbreds were detected with MRSE (HFSE1 and HFSE2) and ESBL producing E. coli (HFEC1 and HFEC2), whereas, simultaneous infection of three pathogens viz. MRSA (NDSA1), MRSE (NDSE1) and ESBL producing E. coli (NDEC1) was found in the non-descript cow. The methicillin-resistant isolates possessed mecA gene and exhibited resistance to various antibiotics such as amikacin, tetracycline and glycopeptides. The ESBL producers were positive for blaCTX-M and blaTEM genes; in addition, HFEC1 and HFEC2 were positive for blaSHV and possessed the genes for class I integron (int1), sulphonamide resistance (sul1), quinolone resistance (qnrS) and other virulence factors (papC, iucD and ESTA1). All the ESBL producers exhibited resistance to a variety of antibiotics tested including third- and fourth-generation cephalosporins and were also intermediately resistant to carbapenems. This is the first ever report on simultaneous occurrence of MRSE, MRSA and ESBL producing E. coli in bovine mastitis indicating a major concern for dairy industry and public health as well.

  18. Prevalence of non-aureus staphylococci species causing intramammary infections in Canadian dairy herds.

    Science.gov (United States)

    Condas, Larissa A Z; De Buck, Jeroen; Nobrega, Diego B; Carson, Domonique A; Naushad, Sohail; De Vliegher, Sarne; Zadoks, Ruth N; Middleton, John R; Dufour, Simon; Kastelic, John P; Barkema, Herman W

    2017-07-01

    Non-aureus staphylococci (NAS), the microorganisms most frequently isolated from bovine milk worldwide, are a heterogeneous group of numerous species. To establish their importance as a group, the distribution of individual species needs to be determined. In the present study, NAS intramammary infection (IMI) was defined as a milk sample containing ≥1,000 cfu/mL in pure or mixed culture that was obtained from a cohort of cows assembled by the Canadian Bovine Mastitis Research Network. Overall, 6,213 (6.3%) of 98,233 quarter-milk samples from 5,149 cows and 20,305 udder quarters were associated with an NAS IMI. Of the 6,213 phenotypically identified NAS isolates, 5,509 (89%) were stored by the Canadian Bovine Mastitis Research Network Mastitis Pathogen Collection and characterized using partial sequencing of the rpoB housekeeping gene, confirming 5,434 isolates as NAS. Prevalence of each NAS species IMI was estimated using Bayesian models, with presence of a specific NAS species as the outcome. Overall quarter-level NAS IMI prevalence was 26%. The most prevalent species causing IMI were Staphylococcus chromogenes (13%), Staphylococcus simulans (4%), Staphylococcus haemolyticus (3%), Staphylococcus xylosus (2%), and Staphylococcus epidermidis (1%). The prevalence of NAS IMI as a group was highest in first-parity heifers and was evenly distributed throughout cows in parities ≥2. The IMI prevalence of some species such as S. chromogenes, S. simulans, and S. epidermidis differed among parities. Overall prevalence of NAS IMI was 35% at calving, decreased over the next 10 d, and then gradually increased until the end of lactation. The prevalence of S. chromogenes, Staphylococcus gallinarum, Staphylococcus cohnii, and Staphylococcus capitis was highest at calving, whereas the prevalence of S. chromogenes, S. haemolyticus, S. xylosus, and S. cohnii increased during lactation. Although the overall prevalence of NAS IMI was similar across barn types, the prevalence of S

  19. Meta-Analysis of Transcriptional Responses to Mastitis-Causing Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Sidra Younis

    Full Text Available Bovine mastitis is a widespread disease in dairy cows, and is often caused by bacterial mammary gland infection. Mastitis causes reduced milk production and leads to excessive use of antibiotics. We present meta-analysis of transcriptional profiles of bovine mastitis from 10 studies and 307 microarrays, allowing identification of much larger sets of affected genes than any individual study. Combining multiple studies provides insight into the molecular effects of Escherichia coli infection in vivo and uncovers differences between the consequences of E. coli vs. Staphylococcus aureus infection of primary mammary epithelial cells (PMECs. In udders, live E. coli elicits inflammatory and immune defenses through numerous cytokines and chemokines. Importantly, E. coli infection causes downregulation of genes encoding lipid biosynthesis enzymes that are involved in milk production. Additionally, host metabolism is generally suppressed. Finally, defensins and bacteria-recognition genes are upregulated, while the expression of the extracellular matrix protein transcripts is silenced. In PMECs, heat-inactivated E. coli elicits expression of ribosomal, cytoskeletal and angiogenic signaling genes, and causes suppression of the cell cycle and energy production genes. We hypothesize that heat-inactivated E. coli may have prophylactic effects against mastitis. Heat-inactivated S. aureus promotes stronger inflammatory and immune defenses than E. coli. Lipopolysaccharide by itself induces MHC antigen presentation components, an effect not seen in response to E. coli bacteria. These results provide the basis for strategies to prevent and treat mastitis and may lead to the reduction in the use of antibiotics.

  20. Persistent bacteraemia caused by Staphylococcus aureus in the gall bladder.

    Science.gov (United States)

    Yu, Alexander Tin Han; Cun, Tony; Benamu, Esther; Renault, Cybele

    2017-11-08

    Staphylococcus aureus bacteraemia (SAB) remains a complex disease with a high associated morbidity and mortality, especially when it is able to establish an occult nidus safe from antimicrobial eradication. Without rapid identification and intervention, the nidus can cause persistent relapse of disease, morbidity and mortality. Having a high clinical suspicion for the foci of occult S. aureus is important, and awareness of potential sites of infection is critical and can be life-saving.We present a unique case of a 65-year-old man with end-stage renal disease receiving haemodialysis who developed septic shock from SAB. Despite 18 days of appropriate antibiotics, the patient had persistent high-grade bacteraemia until his gall bladder was ultimately percutaneously drained. The day after drainage, he cleared his blood cultures, although he ultimately passed away as he decided to transition his care to focus on comfort measures. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  1. Changes in Holstein cow milk and serum proteins during intramammary infection with three different strains of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Robert Claude

    2011-09-01

    Full Text Available Abstract Background Staphylococcus aureus is one of the most prevalent pathogens to cause mastitis in dairy cattle. Intramammary infection of dairy cows with S. aureus is often subclinical, due to the pathogen's ability to evade the innate defense mechanisms, but this can lead to chronic infection. A sub-population of S. aureus, known as small colony variant (SCV, displays atypical phenotypic characteristics, causes persistent infections, and is more resistant to antibiotics than parent strains. Therefore, it was hypothesized that the host immune response will be different for SCV than its parental or typical strains of S. aureus. In this study, the local and systemic immune protein responses to intramammary infection with three strains of S. aureus, including a naturally occurring bovine SCV strain (SCV Heba3231, were characterized. Serum and casein-depleted milk cytokine levels (interleukin-8, interferon-γ, and transforming growth factor-β1, as well as serum haptoglobin concentrations were monitored over time after intramammary infection with each of the three S. aureus strains. Furthermore, comparative proteomics was used to evaluate milk proteome profiles during acute and chronic phases of S. aureus intramammary infection. Results Serum IL-8, IFN-γ, and TGF-β1 responses differed in dairy cows challenged with different strains of S. aureus. Changes in overall serum haptoglobin concentrations were observed for each S. aureus challenge group, but there were no significant differences observed between groups. In casein-depleted milk, strain-specific differences in the host IFN-γ response were observed, but inducible IL-8 and TGF-β1 concentrations were not different between groups. Proteomic analysis of the milk following intramammary infection revealed unique host protein expression profiles that were dependent on the infecting strain as well as phase of infection. Notably, the protein, component-3 of the proteose peptone (CPP3, was

  2. Detection of some virulence factors in Staphylococcus aureus ...

    African Journals Online (AJOL)

    Detection of some virulence factors in Staphylococcus aureus isolated from clinical and subclinical bovine mastitis in Iran. ... Mastitis is one of the common diseases of dairy cattle and an inflammatory response of the mammary glands tissue. ... and B genes, 10 samples contained agrI gene, 42 samples contained agrII gene, ...

  3. Ability of Staphylococcus aureus coagulase genotypes to resist neutrophil bactericidal activity and phagocytosis

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Scott, N. L.; Sordillo, L. M.

    1994-01-01

    This study investigated the functional capabilities of neutrophils against different Staphylococcus aureus genotypes isolated from cows with mastitis. Six strains of S. aureus were chosen for use in the study, two with a common genotype, two with an intermediate genotype, and two with a rare......; rare type, 10.5/cell). These findings suggest that one of the reasons for the variation in prevalence of different genotypes of S. aureus in the mammary gland is due to the superior ability of some types to resist phagocytosis and/or killing by bovine neutrophils...

  4. Evaluation of the biofilm forming ability and its associated genes in Staphylococcus species isolates from bovine mastitis in Argentinean dairy farms.

    Science.gov (United States)

    Felipe, Verónica; Morgante, Carolina A; Somale, Paola S; Varroni, Florencia; Zingaretti, María L; Bachetti, Romina A; Correa, Silvia G; Porporatto, Carina

    2017-03-01

    Staphylococcus aureus and coagulase-negative staphylococci (CNS) are important causes of intramammary infection in dairy cattle, and their ability to produce biofilm is considered an important virulence property in the pathogenesis of mastitis. However, the published date on mechanisms and factors involved in infection persistence in the mammary gland remains unclear. The aim of this study was to investigate whether the main Staphylococcus species involved in bovine intramammary infections possess specific characteristics that promote colonization of the udder. We evaluated the biofilm-forming ability and distribution of adhesion- and biofilm-associated genes of Staphylococcus spp. isolated from bovine mastitis infected animals in Argentinean dairy farms. For this purpose, the phenotypic biofilm formation ability of 209 Staphylococcus spp. from bovine mastitis was investigated. All isolates produced biofilm in vitro, being 35,0% and 45,0% of the 127 S. aureus or 51,0% and 29,0% of the 82 CNS strong and moderate biofilm producers respectively. All S. aureus samples were PCR-positive for icaA, icaD, clfA, clfB and fnbpA genes, 76.3% were positive for fnbpB gene and 11.0% were positive for bap gene. In CNS isolates, the positive rates for icaA and icaD were 73.2%, while for clfA, clfB, fnbpA fnbpB and bap genes the percentage were lower. The results demonstrate that in Staphylococcus spp. biofilm formation, the polysaccharide and the adhesion- and biofilm-associated genes are of overall importance on bovine mastitis in Argentina. Therefore, future works should focus on these pathogenic specific factors for the development of more effective therapies of control, being essential to consider the ability of isolates to produce biofilm. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. [Tuberculosis caused by Mycobacterium bovis in workers of bovine tuberculosis sanitation farms in Antioquia, Boyacá and Cundinamarca].

    Science.gov (United States)

    Leal-Bohórquez, Andrés F; Castro-Osorio, Claudia M; Wintaco-Martínez, Luz M; Villalobos, Rafael; Puerto-Castro, Gloria M

    2016-01-01

    To perform classic and molecular epidemiological surveillance of human tuberculosis caused by Mycobacterium bovis in bovine supply chains at farms with PPD positive bovines in the departments of Antioquia, Boyacá and Cundinamarca during a one-year period. Livestock farms with PPD positive bovines or buffalos were visited in the study departments according to information obtained in the "Programa Nacional de Tuberculosis bovina" (National program on bovine Tuberculosis) released by ICA (Colombian Agriculture and Livestock Institute). Data on socio-demographic information and tuberculosis risk factors associated to the occupation were collected through a survey applied to all workers at the visited farms. Sputum samples were obtained after informed consent. The sputa underwent microbiological and molecular testing to identify members of the M. tuberculosis complex. Thirty-three livestock farms were visited and information of 164 workers from the bovine supply chain was collected. Staying in a PPD positive farm for more than a year, ignorance about the disease and the presence of possible vectors, like dogs and cats, were identified as possible risk factors for developing tuberculosis. No cases of tuberculosis caused by M. bovis or M. tuberculosis in workers of the visited farms were found. No cases of the disease caused by this zoonotic agent were documented in the departments of Antioquia, Boyacá and Cundinamarca.

  6. Staphylococcus aureus Isolates from Bovine Mastitis in Eight Countries: Genotypes, Detection of Genes Encoding Different Toxins and Other Virulence Genes

    Directory of Open Access Journals (Sweden)

    Valentina Monistero

    2018-06-01

    Full Text Available Staphylococcus aureus is recognized worldwide as one of the major agents of dairy cow intra-mammary infections. This microorganism can express a wide spectrum of pathogenic factors used to attach, colonize, invade and infect the host. The present study evaluated 120 isolates from eight different countries that were genotyped by RS-PCR and investigated for 26 different virulence factors to increase the knowledge on the circulating genetic lineages among the cow population with mastitis. New genotypes were observed for South African strains while for all the other countries new variants of existing genotypes were detected. For each country, a specific genotypic pattern was found. Among the virulence factors, fmtB, cna, clfA and leucocidins genes were the most frequent. The sea and sei genes were present in seven out of eight countries; seh showed high frequency in South American countries (Brazil, Colombia, Argentina, while sel was harboured especially in one Mediterranean country (Tunisia. The etb, seb and see genes were not detected in any of the isolates, while only two isolates were MRSA (Germany and Italy confirming the low diffusion of methicillin resistance microorganism among bovine mastitis isolates. This work demonstrated the wide variety of S. aureus genotypes found in dairy cattle worldwide. This condition suggests that considering the region of interest might help to formulate strategies for reducing the infection spreading.

  7. The intramammary efficacy of first generation cephalosporins against Staphylococcus aureus mastitis in mice.

    Science.gov (United States)

    Demon, Dieter; Ludwig, Carolin; Breyne, Koen; Guédé, David; Dörner, Julia-Charlotte; Froyman, Robrecht; Meyer, Evelyne

    2012-11-09

    Staphylococcus aureus-induced mastitis in cattle causes important financial losses in the dairy industry due to lower yield and bad milk quality. Although S. aureus is susceptible to many antimicrobials in vitro, treatment often fails to cure the infected udder. Hence, comprehensive evaluation of antimicrobials against S. aureus mastitis is desirable to direct treatment strategies. The mouse mastitis model is an elegant tool to evaluate antimicrobials in vivo while circumventing the high costs associated with bovine experiments. An evaluation of the antimicrobial efficacy of the intramammary (imam) applied first generation cephalosporins cefalexin, cefalonium, cefapirin and cefazolin, was performed using the S. aureus mouse mastitis model. In vivo determination of the effective dose 2log(10) (ED(2log10)), ED(4log10), protective dose 50 (PD(50)) and PD(100) in mouse mastitis studies, support that in vitro MIC data of the cephalosporins did not fully concur with the in vivo clinical outcome. Cefazolin was shown to be the most efficacious first generation cephalosporin to treat S. aureus mastitis whereas the MIC data indicate that cefalonium and cefapirin were more active in vitro. Changing the excipient for imam application from mineral oil to miglyol 812 further improved the antimicrobial efficacy of cefazolin, confirming that the excipient can influence the in vivo efficacy. Additionally, statistical analysis of the variation of S. aureus-infected, excipient-treated mice from fourteen studies emphasizes the strength of the mouse mastitis model as a fast, cost-effective and highly reproducible screening tool to assess the efficacy of antimicrobial compounds against intramammary S. aureus infection. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Frequency of enterotoxins, toxic shock syndrome toxin-1, and biofilm formation genes in Staphylococcus aureus isolates from cows with mastitis in the Northeast of Brazil.

    Science.gov (United States)

    Costa, F N; Belo, N O; Costa, E A; Andrade, G I; Pereira, L S; Carvalho, I A; Santos, R L

    2018-06-01

    Staphylococcus aureus is among the microorganisms more frequently associated with subclinical bovine mastitis. S. aureus may produce several virulence factors. This study aimed at determining the frequency of virulence factors such as enterotoxins, toxic shock syndrome toxin 1, and ica adhesion genes. In addition, we assessed antimicrobial drug resistance in S. aureus isolated from clinical and subclinical cases of mastitis. A total of 88 cows with clinical or subclinical mastitis were sampled, resulting in 38 S. aureus isolates, from which 25 (65.78%) carried toxin genes, including seb, sec, sed, tst, and icaD adhesion gene. These S. aureus isolates belong to 21 ribotypes and three S. aureus strains belonged to the same ribotype producing ica adhesion gene. Approximately 90% of S. aureus strains obtained in our study demonstrated multiple resistance to different antimicrobial agents. The most efficacious antimicrobial agents against the isolates were gentamicin, amoxicillin, and norfloxacin. Gentamicin was the most efficacious agent inhibiting 78.95% of the S. aureus isolates. The least efficacious were penicillin, streptomycin, and ampicillin. Our results can help in understanding the relationship between virulence factors and subclinical mastitis caused by S. aureus. Further research about diversity of S. aureus isolates and genes responsible for the pathogenicity of subclinical mastitis is essential.

  9. Bovine mastitis: prevalence and antimicrobial susceptibility profile and detection of genes associated with biofilm formation in Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Valeska Paula Casanova

    2016-06-01

    Full Text Available Brazil currently ranks as one of the world leaders in food production and exportation. This scenario encourages the development of animal and plant health programs to ensure the production of safe food, helping the country to become an international provider of food for excellence. However, some health problems in dairy production, such as mastitis, have garnered increasing concern. This study aimed to estimate the prevalence of bovine mastitis in select properties located in the western Santa Catarina region, to assess the susceptibility profile to antimicrobial agents used for treatment and to check for the presence of genes (icaA and icaD associated with biofilm formation in Staphylococcus aureus. In 148 milk samples collected, 72.97% had bacterial growth (n = 108. Among the isolated microorganisms, 21.62% (n = 32 were classified as Staphylococcus aureus, 18.91% (n = 28 as Staphylococcus sp. coagulase negative, 7.43% (n = 11 as Corynebacterium sp., 6.76% (n = 10 as Staphylococcus sp. coagulase positive, 5.41% (n = 8 as Nocardia sp. and 12.83% (n = 19 classified in different bacterial genera. Among the isolates submitted for antimicrobial susceptibility testing, it was observed that 8.95% (n = 6/67 had resistance to amoxicillin, 8.04% (n = 7/87 to ampicillin, 5.88% (n = 5/85 to cephalothin, 3.40% (n = 3/88 to ceftiofur and enrofloxacin, 20.45% (n = 18/88 to streptomycin, 17.04% (n = 15/88 to gentamicin and lincomycin, 31.81% (n = 28/88 to neomycin, 14.94% (n = 13/87 to penicillin and 25% (n = 22/88 to tetracycline. Staphylococcus sp. coagulase negative isolates showed higher multidrug resistance when compared to those of S. aureus and Staphylococcus sp. coagulase positive. Thirty-one strains of S. aureus isolates were genotypically tested by polymerase chain reaction (PCR, yielding a positive result for the icaA gene in 83.87% of the samples, 80.64% positive for icaD and 74.19% of these showed both genes. The results reinforce the importance

  10. In vitro activity of ivermectin against Staphylococcus aureus clinical isolates

    Directory of Open Access Journals (Sweden)

    Shoaib Ashraf

    2018-02-01

    Full Text Available Abstract Background Ivermectin is an endectocide against many parasites. Though being a macrocyclic lactone, its activity against bacteria has been less known, possibly due to the fact that micromolar concentrations at tissue levels are required to achieve a therapeutic effect. Among pathogenic bacteria of major medical significance, Staphylococcus aureus cause a number of diseases in a wide variety of hosts including humans and animals. It has been attributed as one of the most pathogenic organisms. The emergence of methicillin resistance has made the treatment of S. aureus even more difficult as it is now resistant to most of the available antibiotics. Thus, search for alternate anti-staphylococcal agents requires immediate attention. Methods Twenty-one clinical isolates of S. aureus were isolated from bovine milk collected from Lahore and Faisalabad Pakistan. Different anthelmintics including levamisole, albendazole and ivermectin were tested against S. aureus to determine their minimum inhibitory concentrations. This was followed-up by growth curve analysis, spot assay and time-kill kinetics. Results The results showed that ivermectin but not levamisole or albendazole exhibited a potent anti-staphylococcal activity at the concentrations of 6.25 and 12.5 μg/ml against two isolates. Interestingly, one of the isolate was sensitive while the other was resistant to methicillin/cefoxitin. Conclusions Our novel findings indicate that ivermectin has an anti-bacterial effect against certain S. aureus isolates. However, to comprehend why ivermectin did not inhibit the growth of all Staphylococci needs further investigation. Nevertheless, we have extended the broad range of known pharmacological effects of ivermectin. As pharmacology and toxicology of ivermectin are well known, its further development as an anti-staphylococcal agent is potentially appealing.

  11. Efeito dos óleos essenciais de Syzygium aromaticum e Cinnamomum zeylanicume e seus compostos majoritários na produçao de biofilme em cepas de Staphylococcus aureus, isolados de leite de vacas com mastite subclínica

    OpenAIRE

    Budri, Paulo Eduardo [UNESP

    2014-01-01

    Bovine Mastitis is an inflammation of the mammary gland of cows causing economic losses in dairy cattle and Staphylococcus aureus is one of the microorganisms most commonly isolated in this kind of disease. The production of biofilms by S. aureus is an important virulence factor and spreed of this microorganism, involving the adhesion of bacteria on solid surfaces. In this work we tested the essential oils of Syzygium aromaticum (OESA) and Cinnamomum zeylanicum (OECZ) and their major compound...

  12. Isolation and characterization of a virulent bacteriophage SPW specific for Staphylococcus aureus isolated from bovine mastitis of lactating dairy cattle.

    Science.gov (United States)

    Li, Longping; Zhang, Zhiying

    2014-09-01

    Mastitis in dairy cattle continues to be an economically important disease. However, control is complicated by a high prevalence of resistance to antibiotics. Phage therapy, therefore, is considered as an alternative way of controlling bacterial infections and contaminations. In this study, we have described isolation and characterization of a highly virulent phage SPW from wastewater of dairy farm, which possesses a strong lytic capability against mastitis-associated Staphylococcus aureus, the most important pathogen in bovine clinical and subclinical mastitis. The phage SPW produced large, round and clear plaques on bacterial culture plates. TEM showed phage SPW has an icosahedral head 62.5 nm in diameter and long tail of 106 nm, head and tail were held together by a connector of 18 ± 1.5 nm long and can be classified as a member of the Myoviridae family. Restriction analysis indicated that phage SPW was a dsDNA virus with an approximate genome size of 65-69 kb. One-step growth kinetics showed a short latency period of about 10-15 min and a rise period of 50 min and a relatively small burst size was 44 ± 3 phages particles/infected cell. Moreover, adsorption rates were not influenced by calcium ions and phage SPW was relatively stable in a wide range of temperature and pH values, and resistant to chloroform and isopropanol. The optimal multiplicity of infection (MOI) was 0.01. When phage SPW was used to infect five other clinically isolated pathogenic isolates, it showed relatively wide spectrum host range. Phage SPW was capable of eliciting efficient lysis of S. aureus, revealing it potentially as an effective approach to prophylaxis or treatment of S. aureus-associated mastitis in dairy cows.

  13. Long-term mortality and causes of death associated with Staphylococcus aureus bacteremia

    DEFF Research Database (Denmark)

    Gotland, N; Uhre, M L; Mejer, N

    2016-01-01

    OBJECTIVES: Data describing long-term mortality in patients with Staphylococcus aureus bacteremia (SAB) is scarce. This study investigated risk factors, causes of death and temporal trends in long-term mortality associated with SAB. METHODS: Nationwide population-based matched cohort study...... respiratory disease, nervous system disease, unknown causes, psychiatric disorders, cardiovascular disease and senility. Over time, rates of death decreased or were stable for all disease categories except for musculoskeletal and skin disease where a trend towards an increase was seen. CONCLUSION: Long......-term mortality after SAB was high but decreased over time. SAB cases were more likely to die of eight specific causes of death and less likely to die of five other causes of death compared to controls. Causes of death decreased for most disease categories. Risk factors associated with long-term mortality were...

  14. Differential responses of cells from human skin keratinocyte and bovine mammary epithelium to attack by pore-forming Staphylococcus aureus alpha-toxin.

    Science.gov (United States)

    Suriyaphol, Gunnaporn; Sarikaputi, Meena; Suriyaphol, Prapat

    2009-11-01

    Human skin keratinocytes HaCat attacked by Staphylococcus aureus alpha-toxin showed a transient drop of cellular ATP levels whereas in toxin-perforated bovine mammary epithelial cells (BMEC), the ATP levels dropped more slowly. Morphologically, during the ATP level depletion, HaCat cell developed a spacious intracellular vacuole together with the transient influx of trypan blue. WST-1 signal, which tested the function of mitochondrial enzyme in viable cells, also decreased concomitantly. On the other hand, BMEC excluded trypan blue and vacuolation was not observed throughout the experiment. We conclude that mammary epithelial cells resist the toxin better than keratinocytes. This is the first report showing that alpha-toxin enhances transient membrane permeability to large molecules, temporary vacuole formation and the transient defect of mitochondrial enzyme in viable cells without cell lysis.

  15. Staphylococcus aureus entrance into the dairy chain: Tracking S. aureus from dairy cow to cheese

    Directory of Open Access Journals (Sweden)

    Judith Kümmel

    2016-10-01

    Full Text Available Staphylococcus aureus is one of the most important contagious mastitis pathogens in dairy cattle. Due to its zoonotic potential, control of S. aureus is not only of great economic importance in the dairy industry but also a significant public health concern. The aim of this study was to decipher the potential of bovine udder associated S. aureus as reservoir for S. aureus contamination in dairy production and processing. From 18 farms, delivering their milk to an alpine dairy plant for the production of smeared semi-hard and hard cheese. 1176 quarter milk (QM samples of all cows in lactation (n = 294 and representative samples form bulk tank milk (BTM of all farms were surveyed for coagulase positive (CPS and coagulase negative Staphylococci (CNS. Furthermore, samples from different steps of the cheese manufacturing process were tested for CPS and CNS. As revealed by chemometric-assisted FTIR spectroscopy and molecular subtyping (spa typing and multi locus sequence typing, dairy cattle represent indeed an important, yet underreported, entrance point of S. aureus into the dairy chain. Our data clearly show that certain S. aureus subtypes are present in primary production as well as in the cheese processing at the dairy plant. However, although a considerable diversity of S. aureus subtypes was observed in QM and BTM at the farms, only certain S. aureus subtypes were able to enter and persist in the cheese manufacturing at the dairy plant and could be isolated from cheese until day fourteen of ripening. Farm strains belonging to the FTIR cluster B1 and B3, which show genetic characteristics (t2953, ST8, enterotoxin profile: sea/sed/sej of the recently described S. aureus genotype B, most successfully contaminated the cheese production at the dairy plant. Thus our study fosters the hypothesis that genotype B S. aureus represent a specific challenge in control of S. aureus in the dairy chain that requires effective clearance strategies and hygienic

  16. Increasing resistant coagulase negative staphylococci in bovine clinical mastitis.

    Science.gov (United States)

    Moniri, R; Dastehgoli, K; Akramian, A

    2007-08-01

    The aim of this study was to determine Coagulase Negative Staphylococci (CNS) and other bacteria for their resistance to antimicrobial agents approved for the control of pathogens involved in clinical bovine mastitis. This descriptive study was done on 106 milk samples obtained from clinical mastitis in dairy cattle husbandry from April 2006 through August 2006 in Kashan, Iran. From the total of 106 milk samples collected from clinical mastitis, 96 (90.6%) lead to positive culture. Coagulase negative Staphylococci isolated in 51 out of 96 samples (53.1%), Staphylococcus aureus isolated in 21 out of 96 (21.9%), gram negative bacilli isolated in 14 out of 96 (14.6%) and Enterococci isolated in 4 (4.2%). The highest rate of resistant CNS observed to penicillin (56.6%) and the highest rate of sensitivity to enrofloxacin 100%, followed by kanamycin, streptomycin and neomycin, 92.2, 82.3 and 82.3%, respectively. The highest rate of resistance S. aureus exhibited to penicillin (66.6%); while the highest rate of sensitivity showed to trimethoprim-sulphamethoxasole (81%), followed by kanamycin and enrofloxacin both at 76.2%. The highest rate of resistance gram negative bacilli exhibited to ampicillin and erythromycin at 71.4%. Their highest rate of sensitivity observed to enrofloxacin (78.6%), followed by kanamycin, (71.4%). In recent years, CNS is emerging as important minor mastitis pathogens and can be the cause of substantial economic losses. The high resistance rate to penicillin and other antibiotics found in this study emphasize the importance of identification of CNS when a bovine clinical mastitis is present.

  17. Bovine CCL28 Mediates Chemotaxis via CCR10 and Demonstrates Direct Antimicrobial Activity against Mastitis Causing Bacteria.

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    Kyler B Pallister

    Full Text Available In addition to the well characterized function of chemokines in mediating the homing and accumulation of leukocytes to tissues, some chemokines also exhibit potent antimicrobial activity. Little is known of the potential role of chemokines in bovine mammary gland health and disease. The chemokine CCL28 has previously been shown to play a key role in the homing and accumulation of IgA antibody secreting cells to the lactating murine mammary gland. CCL28 has also been shown to act as an antimicrobial peptide with activity demonstrated against a wide range of pathogens including bacteria, fungi and protozoans. Here we describe the cloning and function of bovine CCL28 and document the concentration of this chemokine in bovine milk. Bovine CCL28 was shown to mediate cellular chemotaxis via the CCR10 chemokine receptor and exhibited antimicrobial activity against a variety of bovine mastitis causing organisms. The concentration of bovine CCL28 in milk was found to be highly correlated with the lactation cycle. Highest concentrations of CCL28 were observed soon after parturition, with levels decreasing over time. These results suggest a potential role for CCL28 in the prevention/resolution of bovine mastitis.

  18. In vitro antimicrobial susceptibility of Staphylococcus aureus strains from dairy herds in KwaZulu-Natal

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    T. Schmidt

    2011-04-01

    Full Text Available Staphylococcus aureus is 1 of the most important causes of bovine mastitis and is responsible for significant economic losses to the dairy industry worldwide. One of the principal approaches used in treating intramammary infections is the administration of antimicrobials. Due to the propensity of S. aureus to develop resistance, antimicrobial susceptibility monitoring is necessary to ensure that treatment regimens are effective. As part of this investigation, 90 S. aureus strains isolated from mastitis cases submitted to Allerton Provincial Veterinary Laboratory during 2008 and 2009 were evaluated for their susceptibility to a panel of 10 antimicrobials. Only 8 of the 90 S. aureus isolates tested (8.9 % were found to be susceptible to all of the antimicrobials evaluated. A very high level of resistance to the beta-lactam antibiotics was noted: 47.8 % of the isolates were resistant to penicillin and 65.6 % were resistant to ampicillin. Minimal resistance to oxacillin, cephalothin and trimethoprim-sulfamethoxazole (1.1 % was found. Seventeen (18.9 % of the isolates tested were found to be resistant to 3 or more antimicrobials. The need for vigilant monitoring of bacterial resistance trends in the dairy industry is warranted as the potential public health implications are significant.

  19. Proteomic Analysis to Elucidate the Antibacterial Action of Silver Ions Against Bovine Mastitis Pathogens.

    Science.gov (United States)

    Kang, Seog Jin; Cho, Yong Il; Kim, Ki Hyun; Cho, Eun Seok

    2016-05-01

    Silver ions act as a powerful, broad-spectrum antimicrobial agent and are known to kill over 650 different kinds of pathogens. We investigated the protein expression pattern and identity after silver ion treatment in Escherichia coli and Staphylococcus aureus, which are primarily responsible for the majority of bovine mastitis cases using proteomics. Two-dimensional electrophoresis showed that silver ion treatment significantly reduced 5 spot's density in E. coli and S. aureus, respectively. We identified 10 proteins (alkyl hydroperoxide reductase C22 subunit, phosphoglucomutase, fructose-1-phosphate kinase, putative carbamoyl transferase, alpha-galactosidase, carbamate kinase, ornithine transcarbamoylase, fumarate hydratase class II, alcohol dehydrogenase, and conserved hypothetical protein) by matrix-assisted laser desorption ionization time of flight (MALDI-TOF). These results demonstrated that silver ions have bactericidal effects through energy deprivation, inhibition of DNA replication, and accumulation of oxidants in bovine mastitis pathogens and suggested that silver ions can be applied for the treatment of bovine mastitis.

  20. Variabilidades fenotípica e genotípica de estirpes de Staphylococcus aureus isoladas em casos de mastite subclínica bovina Phenotypic and genotypic variabilities of Staphylococcus aureus strains isolated from bovine subclinical mastitis

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    Luciano Menezes Ferreira

    2006-08-01

    antibiotics tested. Of the 19 isolates which presented resistance to antibiotics, 14 (73.7% were grouped in three ribotypes, and 13 (92.9% of them were resistant to eritromycin and/or lincomycin. The large number of ribotypes and antibiotic resistance patterns found in this single dairy herd showed that one must be careful when considering the results of in vitro susceptibility tests obtained from a few S. aureus strains, because there is a high heterogeneity among naturally occurring populations of S. aureus, which must be taken into consideration in control programs against bovine mastitis.

  1. Molecular identification of species of Taenia causing bovine cysticercosis in Ethiopia.

    Science.gov (United States)

    Hailemariam, Z; Nakao, M; Menkir, S; Lavikainen, A; Iwaki, T; Yanagida, T; Okamoto, M; Ito, A

    2014-09-01

    Bovine cysticercosis causing damage to the beef industry is closely linked to human taeniasis due to Taenia saginata. In African countries, Taenia spp. from wildlife are also involved as possible sources of infections in livestock. To identify the aetiological agents of bovine cysticercosis in Ethiopia, cysticerci were collected from 41 cattle slaughtered in the eastern and central areas during 2010-2012. A single cysticercus per animal was subjected to the polymerase chain reaction (PCR)-based DNA sequencing of mitochondrial cytochrome c oxidase subunit 1 gene, and the resultant sequence was compared with those of members of the genus Taenia. Although 38 out of 41 cysticerci (92.7%) were identified as T. saginata, three samples (7.3%) showed the hitherto unknown sequences of Taenia sp., which is distantly related to Taenia solium, Taenia arctos and Taenia ovis. Old literatures suggest it to be Taenia hyaenae, but morphological identification of species could not be completed by observing only the larval samples.

  2. Lactic Acid Bacteria Isolated from Bovine Mammary Microbiota: Potential Allies against Bovine Mastitis.

    Science.gov (United States)

    Bouchard, Damien S; Seridan, Bianca; Saraoui, Taous; Rault, Lucie; Germon, Pierre; Gonzalez-Moreno, Candelaria; Nader-Macias, Fatima M E; Baud, Damien; François, Patrice; Chuat, Victoria; Chain, Florian; Langella, Philippe; Nicoli, Jacques; Le Loir, Yves; Even, Sergine

    2015-01-01

    Bovine mastitis is a costly disease in dairy cattle worldwide. As of yet, the control of bovine mastitis is mostly based on prevention by thorough hygienic procedures during milking. Additional strategies include vaccination and utilization of antibiotics. Despite these measures, mastitis is not fully under control, thus prompting the need for alternative strategies. The goal of this study was to isolate autochthonous lactic acid bacteria (LAB) from bovine mammary microbiota that exhibit beneficial properties that could be used for mastitis prevention and/or treatment. Sampling of the teat canal led to the isolation of 165 isolates, among which a selection of ten non-redundant LAB strains belonging to the genera Lactobacillus and Lactococcus were further characterized with regard to several properties: surface properties (hydrophobicity, autoaggregation); inhibition potential of three main mastitis pathogens, Staphylococcus aureus, Escherichia coli and Streptococcus uberis; colonization capacities of bovine mammary epithelial cells (bMEC); and immunomodulation properties. Three strains, Lactobacillus brevis 1595 and 1597 and Lactobacillus plantarum 1610, showed high colonization capacities and a medium surface hydrophobicity. These strains are good candidates to compete with pathogens for mammary gland colonization. Moreover, nine strains exhibited anti-inflammatory properties, as illustrated by the lower IL-8 secretion by E. coli-stimulated bMEC in the presence of these LAB. Full genome sequencing of five candidate strains allowed to check for undesirable genetic elements such as antibiotic resistance genes and to identify potential bacterial determinants involved in the beneficial properties. This large screening of beneficial properties while checking for undesirable genetic markers allowed the selection of promising candidate LAB strains from bovine mammary microbiota for the prevention and/or treatment of bovine mastitis.

  3. Lactic Acid Bacteria Isolated from Bovine Mammary Microbiota: Potential Allies against Bovine Mastitis.

    Directory of Open Access Journals (Sweden)

    Damien S Bouchard

    Full Text Available Bovine mastitis is a costly disease in dairy cattle worldwide. As of yet, the control of bovine mastitis is mostly based on prevention by thorough hygienic procedures during milking. Additional strategies include vaccination and utilization of antibiotics. Despite these measures, mastitis is not fully under control, thus prompting the need for alternative strategies. The goal of this study was to isolate autochthonous lactic acid bacteria (LAB from bovine mammary microbiota that exhibit beneficial properties that could be used for mastitis prevention and/or treatment. Sampling of the teat canal led to the isolation of 165 isolates, among which a selection of ten non-redundant LAB strains belonging to the genera Lactobacillus and Lactococcus were further characterized with regard to several properties: surface properties (hydrophobicity, autoaggregation; inhibition potential of three main mastitis pathogens, Staphylococcus aureus, Escherichia coli and Streptococcus uberis; colonization capacities of bovine mammary epithelial cells (bMEC; and immunomodulation properties. Three strains, Lactobacillus brevis 1595 and 1597 and Lactobacillus plantarum 1610, showed high colonization capacities and a medium surface hydrophobicity. These strains are good candidates to compete with pathogens for mammary gland colonization. Moreover, nine strains exhibited anti-inflammatory properties, as illustrated by the lower IL-8 secretion by E. coli-stimulated bMEC in the presence of these LAB. Full genome sequencing of five candidate strains allowed to check for undesirable genetic elements such as antibiotic resistance genes and to identify potential bacterial determinants involved in the beneficial properties. This large screening of beneficial properties while checking for undesirable genetic markers allowed the selection of promising candidate LAB strains from bovine mammary microbiota for the prevention and/or treatment of bovine mastitis.

  4. Bovine mastitis prevention: humoral and cellular response of dairy cows inoculated with lactic acid bacteria at the dry-off period.

    Science.gov (United States)

    Pellegrino, M; Berardo, N; Giraudo, J; Nader-Macías, M E F; Bogni, C

    2017-08-24

    The use of lactic acid bacteria (LAB) in animal feed, constitute an alternative tool for bovine mastitis prevention. Previously, two LAB strains were isolated from bovine milk and selected for their probiotics properties. So far, immune response of inoculating LAB in bovine udders at dry-off period has not been investigated. The immunoglobulin isotype levels and memory cell proliferation in blood and milk of animals inoculated with Lactobacillus lactis subsp. lactis CRL1655 and Lactobacillus perolens CRL1724 at dry-off period was studied. Ten animals were inoculated intramammarily with 10 6 cells of each LAB (IG) and 2 animals used as control (NIG). Milk and blood samples were taken before inoculation and 1, 2, 4, 6, 12 and 24 h and 7 and 14 days after inoculation. Somatic cell count (SCC) in milk, the presence of bovine mastitis pathogens, the levels of antibodies and lymphocyte proliferation were determined. In the IG, the SCC was bovine mastitis pathogens after 24-48 h of incubation. In general, LAB inoculation increased the amount of IgG isotypes in blood and milk, and these antibodies were able to recognise Staphylococcus aureus epitopes. Lymphocytes proliferation was significantly higher in the IG at all time points assayed, following LAB or S. aureus stimulation. The lymphocytes of animals inoculated with LAB do not react in vitro to the presence of S. aureus antigen.. The results showed that probiotic microorganisms could be a natural and effective alternative in the prevention of bovine mastitis at dry-off period and act as immunomodulatory stimulating local and systemic defence lines.

  5. Spread of Staphylococcus aureus resistant to penicillin and tetracycline within and between dairy herds

    DEFF Research Database (Denmark)

    Waage, S.; Bjorland, J.; Caugant, D. A.

    2002-01-01

    One hundred and seven bovine isolates of penicillin and tetracycline resistant Staphylococcus aureus, recovered from 25 different dairy herds in various parts of Norway, were characterized using antimicrobial susceptibility testing, multilocus enzyme electrophoresis, ribotyping, plasmid analysis ...

  6. Herd-level association between antimicrobial use and antimicrobial resistance in bovine mastitis Staphylococcus aureus isolates on Canadian dairy farms.

    Science.gov (United States)

    Saini, V; McClure, J T; Scholl, D T; DeVries, T J; Barkema, H W

    2012-04-01

    Surveillance of antimicrobial use and resistance is needed to manage antimicrobial resistance in bacteria. In this study, data were collected on antimicrobial use and resistance in Staphylococcus aureus (n=562), isolated from intramammary infections and (sub)clinical mastitis cases on 89 dairy farms in 4 regions of Canada [Alberta, Ontario, Québec, and the Maritime Provinces (Prince Edward Island, Nova Scotia, and New Brunswick)]. Dairy producers were asked to deposit empty drug containers into specially provided receptacles, and antimicrobial drug use rate was calculated to quantify antimicrobial use. Minimum inhibitory concentrations were determined using the Sensititer bovine mastitis plate system (TREK Diagnostic Systems Inc., Cleveland, OH), containing antimicrobials commonly used for mastitis treatment and control. Multivariable logistic regression models were built to determine herd-level risk factors of penicillin, ampicillin, pirlimycin, penicillin-novobiocin combination, tetracycline and sulfadimethoxine resistance in Staph. aureus isolates. Intramammary administration of the penicillin-novobiocin combination for dry cow therapy was associated with penicillin and ampicillin resistance [odds ratio (OR): 2.17 and 3.10, respectively]. Systemic administration of penicillin was associated with penicillin resistance (OR: 1.63). Intramammary administration of pirlimycin for lactating cow mastitis treatment was associated with pirlimycin resistance as well (OR: 2.07). Average herd parity was associated with ampicillin and tetracycline resistance (OR: 3.88 and 0.02, respectively). Average herd size was also associated with tetracycline resistance (OR: 1.02). Dairy herds in the Maritime region had higher odds of penicillin and lower odds of ampicillin resistance than dairy herds in Québec (OR: 2.18 and 0.19, respectively). Alberta dairy herds had lower odds of ampicillin and sulfadimethoxine resistance than dairy herds in Québec (OR: 0.04 and 0.08, respectively

  7. Detection of methicillin resistance and slime factor production of Staphylococcus aureus in bovine mastitis Detecção de resistência a meticilina e produção do fator slime por Staphylococcus aureus em mastite bovina

    Directory of Open Access Journals (Sweden)

    Alper Ciftci

    2009-06-01

    Full Text Available This study aimed to detect methicillin resistant and slime producing Staphylococcus aureus in cases of bovine mastitis. A triplex PCR was optimized targetting 16S rRNA, nuc and mecA genes for detection of Staphylococcus species, S. aureus and methicillin resistance, respectively. Furthermore, for detection of slime producing strains, a PCR assay targetting icaA and icaD genes was performed. In this study, 59 strains were detected as S. aureus by both conventional tests and PCR, and 13 of them were found to be methicillin resistant and 4 (30.7% were positive for mecA gene. Although 22 of 59 (37.2% S. aureus isolates were slime-producing in Congo Red Agar, in PCR analysis only 15 were positive for both icaA and icaD genes. Sixteen and 38 out of 59 strains were positive for icaA and icaD gene, respectively. Only 2 of 59 strains were positive for both methicillin resistance and slime producing, phenotypically, suggesting lack of correlation between methicillin resistance and slime production in these isolates. In conclusion, the optimized triplex PCR in this study was useful for rapid and reliable detection of methicillin resistant S. aureus. Furthermore, only PCR targetting icaA and icaD may not sufficient to detect slime production and further studies targetting other ica genes should be conducted for accurate evaluation of slime production characters of S. aureus strains.Este estudo objetivou a detecção de Staphylococcus aureus resistente a meticilina e produtor do fator slime em casos de mastite bovina. Um PCR triplex foi otimizado, com alvo no genes 16SrRNA, nuc e mecA para detecção de Staphylococcus spp, S. aureus e resistencia a meticilina, respectivamente. Para detecção das cepas produtoras do fator slime, empregou-se um PCR com alvo nos genes icaA e icaD. No estudo, 59 cepas foram identificadas como S. aureus por testes convencionais e PCR, sendo 13 resistentes a meticilina e quatro positivas para o gene mecA. Embora 22 das 59 cepas

  8. Development of intramammary delivery systems containing lasalocid for the treatment of bovine mastitis: impact of solubility improvement on safety, efficacy, and milk distribution in dairy cattle.

    Science.gov (United States)

    Wang, Wen; Song, Yunmei; Petrovski, Kiro; Eats, Patricia; Trott, Darren J; Wong, Hui San; Page, Stephen W; Perry, Jeanette; Garg, Sanjay

    2015-01-01

    Mastitis is a major disease of dairy cattle. Given the recent emergence of methicillin-resistant Staphylococcus aureus as a cause of bovine mastitis, new intramammary (IMA) treatments are urgently required. Lasalocid, a member of the polyether ionophore class of antimicrobial agents, has not been previously administered to cows by the IMA route and has favorable characteristics for development as a mastitis treatment. This study aimed to develop an IMA drug delivery system (IMDS) of lasalocid for the treatment of bovine mastitis. Minimum inhibitory concentrations (MICs) were determined applying the procedures recommended by the Clinical and Laboratory Standards Institute. Solid dispersions (SDs) of lasalocid were prepared and characterized using differential scanning calorimetry and Fourier transform infrared spectroscopy. IMDSs containing lasalocid of micronized, nano-sized, or as SD form were tested for their IMA safety in cows. Therapeutic efficacy of lasalocid IMDSs was tested in a bovine model involving experimental IMA challenge with the mastitis pathogen Streptococcus uberis. Lasalocid demonstrated antimicrobial activity against the major Gram-positive mastitis pathogens including S. aureus (MIC range 0.5-8 μg/mL). The solubility test confirmed limited, ion-strength-dependent water solubility of lasalocid. A kinetic solubility study showed that SDs effectively enhanced water solubility of lasalocid (21-35-fold). Polyvinylpyrrolidone (PVP)-lasalocid SD caused minimum mammary irritation in treated cows and exhibited faster distribution in milk than either nano or microsized lasalocid. IMDSs with PVP-lasalocid SD provided effective treatment with a higher mastitis clinical and microbiological cure rate (66.7%) compared to cloxacillin (62.5%). Lasalocid SD IMDS provided high cure rates and effectiveness in treating bovine mastitis with acceptable safety in treated cows.

  9. Short communication: Effects of lactose and milk on the expression of biofilm-associated genes in Staphylococcus aureus strains isolated from a dairy cow with mastitis.

    Science.gov (United States)

    Xue, Ting; Chen, Xiaolin; Shang, Fei

    2014-10-01

    Staphylococcus aureus is the main etiological organism responsible for bovine mastitis. The ability of S. aureus to form biofilms plays an important role in the pathogenesis of mastitis. Biofilm formation in S. aureus is associated with the production of polysaccharide intercellular adhesin (PIA) protein and several other proteins. Several environmental factors, including glucose, osmolarity, oleic acid, temperature, and anaerobiosis, have been reported to affect biofilm formation in S. aureus. This study investigated the influence of lactose and milk on the biofilm formation capacity of 2 clinical bovine isolates of S. aureus. We found that lactose increased biofilm formation predominantly by inducing PIA production, whereas milk increased biofilm formation through PIA as well as by increasing the production of other biofilm-associated proteins, which might be mediated by the transcriptional regulators intercellular adhesion regulator (icaR) and repressor of biofilm (rbf). Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  10. Eliminação de resistência a drogas por fluorquinolonas em Staphylococcus aureus de origem bovina Elimination of resistance to drugs by fluoroquinolones in bovine strains of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Maria S.V. Pereira

    2004-03-01

    Full Text Available Cepas de Staphylococcus aureus de origem bovina foram submetidas ao tratamento com quatro fluoquinolonas na concentração subinibitória (1/2 x CMI, para avaliar a influência desses agentes sobre plasmídios. A ciprofloxacina mostrou ser a fluorquinolona mais eficiente, eliminando marcas de resistência para estreptomicina, tetraciclina, penicilina e cádmio. A norfloxacina e a pefloxacina eliminaram resistência para penicilina e tetraciclina, respectivamente; no entanto, não foi evidenciada a eliminação de plasmídio com ofloxacina. Os resultados confirmam a eficácia das fluor-quinolonas em eliminar plasmídios de resistência mostrando a importância desses estudos como contribuição para o entendimento da prevenção de linhagens multiresistentes, uma vez que as quinolonas em concentrações subinibitórias podem aumentar a sensibilidade das linhagens a outros agentes antimicrobianos.Bovine strains of Staphylococcus aureus were submitted to treatment with four fluoro-quinolones in subinhibitory concentrations (1/2 x MICs to evaluate their influence on the curing of plasmids. Ciprofloxacin showed to be the most efficient by eliminating resistance to streptomycin, tetracyclin, penicillin, and cadmium nitrate. Norfloxacin and pefloxacin eliminated penicillin- and tetracyclin-resistance respectively. Otherwise, plasmids elimination by ofloxacin was not evidenced. The results obtained in this study confirm the potential of fluoroquinolones to eliminate antibiotic-resistant plasmids, and showed to be a valuable contribution for the prevention of multi-resistant strains, and may even enhance their sensitivity to other chemotherapeutic agents.

  11. Beta-lactamase detection in Staphylococcus aureus and coagulase-negative Staphylococcus isolated from bovine mastitis

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    Bruno F. Robles

    2014-04-01

    Full Text Available The objectives of the study were to evaluate the presence/production of beta-lactamases by both phenotypic and genotypic methods, verify whether results are dependent of bacteria type (Staphylococcus aureus versus coagulase-negative Staphylococcus - CNS and verify the agreement between tests. A total of 200 bacteria samples from 21 different herds were enrolled, being 100 CNS and 100 S. aureus. Beta-lactamase presence/detection was performed by different tests (PCR, clover leaf test - CLT, Nitrocefin disk, and in vitro resistance to penicillin. Results of all tests were not dependent of bacteria type (CNS or S. aureus. Several S. aureus beta-lactamase producing isolates were from the same herd. Phenotypic tests excluding in vitro resistance to penicillin showed a strong association measured by the kappa coefficient for both bacteria species. Nitrocefin and CLT are more reliable tests for detecting beta-lactamase production in staphylococci.

  12. Risk factors associated with the antimicrobial resistance of Staphylococcus aureus isolated from bovine mastitis

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    Daniele C. Beuron

    2014-10-01

    Full Text Available The objective of this study was to evaluate herd management practices and mastitis treatment procedures as risk factors associated with Staphylococcus aureus antimicrobial resistance. For this study, 13 herds were selected to participate in the study to evaluate the association between their management practices and mastitis treatment procedures and in vitro antimicrobial susceptibility. A total of 1069 composite milk samples were collected aseptically from the selected cows in four different periods over two years. The samples were used for microbiological culturing of S. aureus isolates and evaluation of their antimicrobial susceptibility. A total of 756 samples (70.7% were culture-positive, and S. aureus comprised 27.77% (n=210 of the isolates. The S. aureus isolates were tested using the disk-diffusion susceptibility assay with the following antimicrobials: ampicillin 10mg; clindamycin 2μg; penicillin 1mg; ceftiofur 30μg; gentamicin 10mg; sulfa-trimethoprim 25μg; enrofloxacin 5μg; sulfonamide 300μg; tetracycline 30μg; oxacillin 1mg; cephalothin 30μg and erythromycin 5μg. The variables that were significantly associated with S. aureus resistance were as follows: the treatment of clinical mastitis for ampicillin (OR=2.18, dry cow treatment for enrofloxacin (OR=2.11 and not sending milk samples for microbiological culture and susceptibility tests, for ampicillin (OR=2.57 and penicillin (OR=4.69. In conclusion, the identification of risk factors for S. aureus resistance against various mastitis antimicrobials is an important information that may help in practical recommendations for prudent use of antimicrobial in milk production.

  13. Genetic relatedness and virulence factors of bovine Staphylococcus aureus isolated from teat skin and milk.

    Science.gov (United States)

    da Costa, L B; Rajala-Schultz, P J; Hoet, A; Seo, K S; Fogt, K; Moon, B S

    2014-11-01

    The objective of this study was to assess the role of teat skin colonization in Staphylococcus aureus intramammary infections (IMI) by evaluating genetic relatedness of Staph. aureus isolates from milk and teat skin of dairy cows using pulsed-field gel electrophoresis and characterizing the isolates based on the carriage of virulence genes. Cows in 4 known Staph. aureus-positive herds were sampled and Staph. aureus was detected in 43 quarters of 20 cows, with 10 quarters positive in both milk and skin (20 isolates), 18 positive only in milk, and 15 only on teat skin. Quarters with teat skin colonized with Staph. aureus were 4.5 times more likely to be diagnosed with Staph. aureus IMI than quarters not colonized on teat skin. Three main clusters were identified by pulsed-field gel electrophoresis using a cutoff of 80% similarity. All 3 clusters included both milk and skin isolates. The majority of isolates (72%) belonged to one predominant cluster (B), with 60% of isolates in the cluster originating from milk and 40% from teat skin. Genotypic variability was observed within 10 pairs (formed by isolates originating from milk and teat skin of the same quarter), where isolates in 5 out of the 10 pairs belonged to the same cluster. Forty-two virulence factors were screened using PCR. Some virulence factors were carried more frequently by teat skin isolates than by milk isolates or isolates from quarters with high somatic cell counts. Isolates in the predominant cluster B carried virulence factors clfA and clfB significantly more often than isolates in the minor clusters, which may have assisted them in becoming predominant in the herds. The present findings suggest that teat skin colonization with Staph. aureus can be an important factor involved in Staph. aureus IMI. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Prevalence and characterisation of Staphylococcus aureus causing community-acquired skin and soft tissue infections on Java and Bali, Indonesia.

    Science.gov (United States)

    Santosaningsih, Dewi; Santoso, Sanarto; Setijowati, Nanik; Rasyid, Harun A; Budayanti, Nyoman S; Suata, Ketut; Widhyatmoko, Dicky B; Purwono, Priyo B; Kuntaman, Kuntaman; Damayanti, Damayanti; Prakoeswa, Cita R S; Laurens, Mitchell; van Nierop, Josephine W I; Nanninga, Geraldine L; Oudenes, Neline; de Regt, Michelle; Snijders, Susan V; Verbrugh, Henri A; Severin, Juliëtte A

    2018-01-01

    To define the role of Staphylococcus aureus in community settings among patients with skin and soft tissue infections (SSTI) in Indonesia. Staphylococcus aureus were cultured from anterior nares, throat and wounds of 567 ambulatory patients presenting with SSTI. The mecA gene and genes encoding Panton-Valentine leukocidin (PVL; lukF-PV and lukS-PV) and exfoliative toxin (ET; eta and etb) were determined by PCR. Clonal relatedness among methicillin-resistant S. aureus (MRSA) and PVL-positive S. aureus was analysed using multilocus variable-number tandem-repeat analysis (MLVA) typing, and multilocus sequence typing (MLST) for a subset of isolates. Staphylococcal cassette chromosome mec (SCCmec) was determined for all MRSA isolates. Moreover, determinants for S. aureus SSTI, and PVL/ET-positive vs PVL/ET-negative S. aureus were assessed. Staphylococcus aureus were isolated from SSTI wounds of 257 (45.3%) patients, eight (3.1%) of these were MRSA. Genes encoding PVL and ETs were detected in 21.8% and 17.5% of methicillin-susceptible S. aureus (MSSA), respectively. PVL-positive MRSA was not detected. Nasopharyngeal S. aureus carriage was an independent determinant for S. aureus SSTI (odds ratio [OR] 1.8). Primary skin infection (OR 5.4) and previous antibiotic therapy (OR 3.5) were associated with PVL-positive MSSA. Primary skin infection (OR 2.2) was the only factor associated with ET-positive MSSA. MLVA typing revealed two more prevalent MSSA clusters. One ST1-MRSA-SCCmec type IV isolate and a cluster of ST239-MRSA-SCCmec type III were found. Community-acquired SSTI in Indonesia was frequently caused by PVL-positive MSSA, and the hospital-associated ST239-MRSA may have spread from the hospital into the community. © 2017 John Wiley & Sons Ltd.

  15. Development of intramammary delivery systems containing lasalocid for the treatment of bovine mastitis: impact of solubility improvement on safety, efficacy, and milk distribution in dairy cattle

    Directory of Open Access Journals (Sweden)

    Wang W

    2015-01-01

    Full Text Available Wen Wang,1 Yunmei Song,1 Kiro Petrovski,2 Patricia Eats,2 Darren J Trott,2 Hui San Wong,2 Stephen W Page,3 Jeanette Perry,2 Sanjay Garg11School of Pharmacy and Medical Science, University of South Australia, Adelaide, SA, Australia; 2School of Animal and Veterinary Sciences, University of Adelaide, Adelaide, SA, Australia; 3Luoda Pharma Pty Ltd, Caringbah, NSW, AustraliaBackground: Mastitis is a major disease of dairy cattle. Given the recent emergence of methicillin-resistant Staphylococcus aureus as a cause of bovine mastitis, new intramammary (IMA treatments are urgently required. Lasalocid, a member of the polyether ionophore class of antimicrobial agents, has not been previously administered to cows by the IMA route and has favorable characteristics for development as a mastitis treatment. This study aimed to develop an IMA drug delivery system (IMDS of lasalocid for the treatment of bovine mastitis.Methods: Minimum inhibitory concentrations (MICs were determined applying the procedures recommended by the Clinical and Laboratory Standards Institute. Solid dispersions (SDs of lasalocid were prepared and characterized using differential scanning calorimetry and Fourier transform infrared spectroscopy. IMDSs containing lasalocid of micronized, nano-sized, or as SD form were tested for their IMA safety in cows. Therapeutic efficacy of lasalocid IMDSs was tested in a bovine model involving experimental IMA challenge with the mastitis pathogen Streptococcus uberis.Results: Lasalocid demonstrated antimicrobial activity against the major Gram-positive mastitis pathogens including S. aureus (MIC range 0.5–8 µg/mL. The solubility test confirmed limited, ion-strength-dependent water solubility of lasalocid. A kinetic solubility study showed that SDs effectively enhanced water solubility of lasalocid (21–35-fold. Polyvinylpyrrolidone (PVP-lasalocid SD caused minimum mammary irritation in treated cows and exhibited faster distribution in milk than

  16. Development of intramammary delivery systems containing lasalocid for the treatment of bovine mastitis: impact of solubility improvement on safety, efficacy, and milk distribution in dairy cattle

    Science.gov (United States)

    Wang, Wen; Song, Yunmei; Petrovski, Kiro; Eats, Patricia; Trott, Darren J; Wong, Hui San; Page, Stephen W; Perry, Jeanette; Garg, Sanjay

    2015-01-01

    Background Mastitis is a major disease of dairy cattle. Given the recent emergence of methicillin-resistant Staphylococcus aureus as a cause of bovine mastitis, new intramammary (IMA) treatments are urgently required. Lasalocid, a member of the polyether ionophore class of antimicrobial agents, has not been previously administered to cows by the IMA route and has favorable characteristics for development as a mastitis treatment. This study aimed to develop an IMA drug delivery system (IMDS) of lasalocid for the treatment of bovine mastitis. Methods Minimum inhibitory concentrations (MICs) were determined applying the procedures recommended by the Clinical and Laboratory Standards Institute. Solid dispersions (SDs) of lasalocid were prepared and characterized using differential scanning calorimetry and Fourier transform infrared spectroscopy. IMDSs containing lasalocid of micronized, nano-sized, or as SD form were tested for their IMA safety in cows. Therapeutic efficacy of lasalocid IMDSs was tested in a bovine model involving experimental IMA challenge with the mastitis pathogen Streptococcus uberis. Results Lasalocid demonstrated antimicrobial activity against the major Gram-positive mastitis pathogens including S. aureus (MIC range 0.5–8 μg/mL). The solubility test confirmed limited, ion-strength-dependent water solubility of lasalocid. A kinetic solubility study showed that SDs effectively enhanced water solubility of lasalocid (21–35-fold). Polyvinylpyrrolidone (PVP)-lasalocid SD caused minimum mammary irritation in treated cows and exhibited faster distribution in milk than either nano or microsized lasalocid. IMDSs with PVP-lasalocid SD provided effective treatment with a higher mastitis clinical and microbiological cure rate (66.7%) compared to cloxacillin (62.5%). Conclusion Lasalocid SD IMDS provided high cure rates and effectiveness in treating bovine mastitis with acceptable safety in treated cows. PMID:25653501

  17. Two splice variants of the bovine lactoferrin gene identified in Staphylococcus aureus isolated from mastitis in dairy cattle.

    Science.gov (United States)

    Huang, J M; Wang, Z Y; Ju, Z H; Wang, C F; Li, Q L; Sun, T; Hou, Q L; Hang, S Q; Hou, M H; Zhong, J F

    2011-12-21

    Bovine lactoferrin (bLF) is a member of the transferrin family; it plays an important role in the innate immune response. We identified novel splice variants of the bLF gene in mastitis-infected and healthy cows. Reverse transcription-polymerase chain reaction (RT-PCR) and clone sequencing analysis were used to screen the splice variants of the bLF gene in the mammary gland, spleen and liver tissues. One main transcript corresponding to the bLF reference sequence was found in three tissues in both healthy and mastitis-infected cows. Quantitative real-time PCR analysis showed that the expression levels of the LF gene's main transcript were not significantly different in tissues from healthy versus mastitis-infected cows. However, the new splice variant, LF-AS2, which has the exon-skipping alternative splicing pattern, was only identified in mammary glands infected with Staphylococcus aureus. Sequencing analysis showed that the new splice variant was 251 bp in length, including exon 1, part of exon 2, part of exon 16, and exon 17. We conclude that bLF may play a role in resistance to mastitis through alternative splicing mechanisms.

  18. Studies on the antimicrobial properties of colloidal silver nanoparticles stabilized by bovine serum albumin.

    Science.gov (United States)

    Mathew, Thomas V; Kuriakose, Sunny

    2013-01-01

    Colloidal silver nanoparticles were synthesised using sol-gel method and these nanoparticles were stabilised by encapsulated into the scaffolds of bovine serum albumin. Silver nanoparticles and encapsulated products were characterised by FTIR, NMR, XRD, TG, SEM and TEM analyses. Silver nanoparticle encapsulated bovine serum albumin showed highly potent antibacterial activity towards the bacterial strains such as Staphylococcus aureus, Serratia marcescens, Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. High-Level Expression of Recombinant Bovine Lactoferrin in Pichia pastoris with Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Blanca Iglesias-Figueroa

    2016-06-01

    Full Text Available In this study, bovine lactoferrin (bLf, an iron-binding glycoprotein considered an important nutraceutical protein because of its several properties, was expressed in Pichia pastoris KM71-H under AOX1 promoter control, using pJ902 as the recombinant plasmid. Dot blotting analysis revealed the expression of recombinant bovine lactoferrin (rbLf in Pichia pastoris. After Bach fermentation and purification by molecular exclusion, we obtained an expression yield of 3.5 g/L of rbLf. rbLf and predominantly pepsin-digested rbLf (rbLfcin demonstrated antibacterial activity against Escherichia coli (E. coli BL21DE3, Staphylococcus aureus (S. aureus FRI137, and, in a smaller percentage, Pseudomonas aeruginosa (Ps. Aeruginosa ATCC 27833. The successful expression and characterization of functional rbLf expressed in Pichia pastoris opens a prospect for the development of natural antimicrobial agents produced recombinantly.

  20. Methicillin-resistant Staphylococcus aureus containing mecC in Swedish dairy cows

    Directory of Open Access Journals (Sweden)

    Unnerstad Helle Ericsson

    2013-01-01

    Full Text Available Abstract Background Hitherto, methicillin-resistant Staphylococcus aureus (MRSA has not been detected in Swedish cattle. However, due to the report of mecC, a novel homologue to the mecA gene, there was reason to re-evaluate susceptibility results from strain collections of Staphylococcus aureus and test suspected isolates for the presence of mecC. Findings Bovine isolates of S. aureus with elevated minimum inhibitory concentrations of beta-lactams were retrospectively tested for presence of mecC. In four of the isolates mecC was detected. Conclusion In Sweden, this is the first finding of MRSA in cattle and the first detection of MRSA harbouring mecC of domestic animal origin. MRSA in animal populations has implications as a potential reservoir with risk for spread to humans. Occurrence of MRSA among Swedish cattle appears still very limited.

  1. Bioeconomic modeling of lactational antimicrobial treatment of new bovine subclinical intramammary infections caused by contagious pathogens

    NARCIS (Netherlands)

    Borne, van den B.H.P.; Halasa, T.; Schaik, van G.; Hogeveen, H.; Nielen, M.

    2010-01-01

    This study determined the direct and indirect epidemiologic and economic effects of lactational treatment of new bovine subclinical intramammary infections (IMI) caused by contagious pathogens using an existing bioeconomic model. The dynamic and stochastic model simulated the dynamics of

  2. Comparative genome analysis of 24 bovine-associated Staphylococcus isolates with special focus on the putative virulence genes

    Science.gov (United States)

    Åvall-Jääskeläinen, Silja; Paulin, Lars; Blom, Jochen

    2018-01-01

    Non-aureus staphylococci (NAS) are most commonly isolated from subclinical mastitis. Different NAS species may, however, have diverse effects on the inflammatory response in the udder. We determined the genome sequences of 20 staphylococcal isolates from clinical or subclinical bovine mastitis, belonging to the NAS species Staphylococcus agnetis, S. chromogenes, and S. simulans, and focused on the putative virulence factor genes present in the genomes. For comparison we used our previously published genome sequences of four S. aureus isolates from bovine mastitis. The pan-genome and core genomes of the non-aureus isolates were characterized. After that, putative virulence factor orthologues were searched in silico. We compared the presence of putative virulence factors in the NAS species and S. aureus and evaluated the potential association between bacterial genotype and type of mastitis (clinical vs. subclinical). The NAS isolates had much less virulence gene orthologues than the S. aureus isolates. One third of the virulence genes were detected only in S. aureus. About 100 virulence genes were present in all S. aureus isolates, compared to about 40 to 50 in each NAS isolate. S. simulans differed the most. Several of the virulence genes detected among NAS were harbored only by S. simulans, but it also lacked a number of genes present both in S. agnetis and S. chromogenes. The type of mastitis was not associated with any specific virulence gene profile. It seems that the virulence gene profiles or cumulative number of different virulence genes are not directly associated with the type of mastitis (clinical or subclinical), indicating that host derived factors such as the immune status play a pivotal role in the manifestation of mastitis. PMID:29610707

  3. Comparative genome analysis of 24 bovine-associated Staphylococcus isolates with special focus on the putative virulence genes

    Directory of Open Access Journals (Sweden)

    Silja Åvall-Jääskeläinen

    2018-03-01

    Full Text Available Non-aureus staphylococci (NAS are most commonly isolated from subclinical mastitis. Different NAS species may, however, have diverse effects on the inflammatory response in the udder. We determined the genome sequences of 20 staphylococcal isolates from clinical or subclinical bovine mastitis, belonging to the NAS species Staphylococcus agnetis, S. chromogenes, and S. simulans, and focused on the putative virulence factor genes present in the genomes. For comparison we used our previously published genome sequences of four S. aureus isolates from bovine mastitis. The pan-genome and core genomes of the non-aureus isolates were characterized. After that, putative virulence factor orthologues were searched in silico. We compared the presence of putative virulence factors in the NAS species and S. aureus and evaluated the potential association between bacterial genotype and type of mastitis (clinical vs. subclinical. The NAS isolates had much less virulence gene orthologues than the S. aureus isolates. One third of the virulence genes were detected only in S. aureus. About 100 virulence genes were present in all S. aureus isolates, compared to about 40 to 50 in each NAS isolate. S. simulans differed the most. Several of the virulence genes detected among NAS were harbored only by S. simulans, but it also lacked a number of genes present both in S. agnetis and S. chromogenes. The type of mastitis was not associated with any specific virulence gene profile. It seems that the virulence gene profiles or cumulative number of different virulence genes are not directly associated with the type of mastitis (clinical or subclinical, indicating that host derived factors such as the immune status play a pivotal role in the manifestation of mastitis.

  4. Interaction between bovine-associated coagulase-negative staphylococci species and strains and bovine mammary epithelial cells reflects differences in ecology and epidemiological behavior.

    Science.gov (United States)

    Souza, F N; Piepers, S; Della Libera, A M M P; Heinemann, M B; Cerqueira, M M O P; De Vliegher, S

    2016-04-01

    Bacteria adherence seems to be an essential first stage for the internalization of bacteria into the cytoplasm of the host cell, which is considered an important virulence strategy enabling bacteria to occupy a microenvironment separated from host defense mechanisms. Thus, this study aimed to explore the difference in the capacity of 4 bovine-associated staphylococci species or strains to adhere to and internalize into bovine mammary epithelial cells (MEC). Three different isolates of coagulase-negative staphylococci (CNS) were used: one strain of Staphylococcus fleurettii isolated from sawdust and considered an environmental opportunistic bacterium, and 2 dissimilar Staphylococcus chromogenes isolates, one cultured from a heifer's teat apex (Staph. chromogenes TA) and the other originating from a chronic intramammary infection (Staph. chromogenes IM). Also, one well-characterized strain of Staphylococcus aureus (Newbould 305) was used for comparison with a major mastitis pathogen. The CNS species and strains adhered to and internalized into MEC slower than did Staph. aureus. Still, we observed high variation in adhesion and internalization capacity among the different CNS, with Staph. chromogenes IM showing a greater ability to adhere to and internalize into MEC than the 2 CNS strains isolated from extramammary habitats. In conclusion, the 3 well-characterized bovine-associated CNS species and strains originating from distinct habitats showed clear differences in their capacity to adhere to and internalize into MEC. The observed differences might be related to their diversity in ecology and epidemiological behavior. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  5. Sodium Octanoate Modulates the Innate Immune Response of Bovine Mammary Epithelial Cells through the TLR2/P38/JNK/ERK1/2 Pathway: Implications during Staphylococcus aureus Internalization.

    Science.gov (United States)

    Alva-Murillo, Nayeli; Ochoa-Zarzosa, Alejandra; López-Meza, Joel E

    2017-01-01

    Bovine mammary epithelial cells (bMECs) contribute to mammary gland defense against invading pathogens, such as Staphylococcus aureus (intracellular facultative), which is recognized by TLR2. In a previous report, we showed that sodium octanoate [NaO, a medium chain fatty acid (C8)] induces (0.25 mM) or inhibits (1 mM) S. aureus internalization into bMECs and differentially regulates the innate immune response (IIR). However, the molecular mechanisms have not been described, which was the aim of this study. The results showed that α5β1 integrin membrane abundance (MA) was increased in 0.25 mM NaO-treated cells, but TLR2 or CD36 MA was not modified. When these receptors were blocked individually, 0.25 mM NaO-increased S. aureus internalization was notably reduced. Interestingly, in this condition, the IIR of the bMECs was impaired because MAPK (p38, JNK, and ERK1/2) phosphorylation and the activation of transcription factors related to these pathways were decreased. In addition, the 1 mM NaO treatment induced TLR2 MA, but neither the integrin nor CD36 MA was modified. The reduction in S. aureus internalization induced by 1 mM NaO was increased further when TLR2 was blocked. In addition, the phosphorylation levels of the MAPKs increased, and 13 transcriptional factors related to the IIR were slightly activated (CBF, CDP, c-Myb, AP-1, Ets-1/Pea-3, FAST-1, GAS/ISRE, AP-2, NFAT-1, OCT-1, RAR/DR-5, RXR/DR-1, and Stat-3). Moreover, the 1 mM NaO treatment up-regulated gene expression of IL-8 and RANTES and secretion of IL-1β. Notably, when 1 mM NaO-treated bMECs were challenged with S. aureus , the gene expression of IL-8 and IL-10 increased, while IL-1β secretion was reduced. In conclusion, our results showed that α5β1 integrin, TLR2 and CD36 are involved in 0.25 mM NaO-increased S. aureus internalization in bMECs. In addition, 1 mM NaO activates bMECs via the TLR2 signaling pathways (p38, JNK, and ERK1/2), which improves IIR before S. aureus invasion. Additionally

  6. Molecular characteristics of bap-positive Staphylococcus aureus strains from dairy cow mastitis.

    Science.gov (United States)

    Snel, Gustavo G M; Monecke, Stefan; Ehricht, Ralf; Piccinini, Renata

    2015-08-01

    The biofilm-associated protein (Bap) of Staphylococcus aureus is a high molecular weight cell-wall-anchored protein involved in biofilm formation, first described in bovine mastitis strains from Spain. So far, studies regarding Bap were mainly based on the Spanish strain V329 and its mutants, but no information on the genetic variability of bap-positive Staph. aureus strains is yet available in the literature. The present study investigated the molecular characteristics of 8 bap-positive Staph. aureus strains from subclinical bovine mastitis, isolated in 5 herds; somatic cell counts (SCC) of milk samples were also registered. Strains were characterised using MLST, SPA typing and microarray and the results were compared with V329. All isolates from this study and V329 were assigned to ST126, t605, but some molecular differences were observed. Only herd A and B strains harboured the genes for β-lactams resistance; the leukocidin D/E gene, a type I site-specific deoxyribonuclease subunit, 3rd locus gene and serin-protease A and B were carried by all strains, but not by V329, while serin-protease E was absent in V329 and in another isolate. Four isolates and V329 harboured the fibronectin-binding protein B gene. SCC showed the highest value in the milk sample affected by the only strain carrying all the virulence factors considered. Potential large variability of virulence was evidenced among V329 and all bap-positive Staph. aureus strains considered: the carriage of fnb could enhance the accumulation of biofilm, but the lack of lukD/E and splA, B or E might decrease the invasiveness of strain.

  7. Relationship and susceptibility profile of Staphylococcus aureus infection diabetic foot ulcers with Staphylococcus aureus nasal carriage.

    Science.gov (United States)

    Taha, Aza Bahadeen

    2013-03-01

    Staphylococcus aureus is the main cause of diabetic foot infection with the patient's endogenous flora as the principal source. Nasal carriage of S. aureus has been identified as an important risk factor for the acquisition of diabetic foot infections. The study assessment the associations of S. aureus with methicillin resistant S. aureus were isolation from diabetic foot infection and nasal carriage of the same patients and their antibiotic susceptibility profile. Diagnosis of S. aureus and methicillin resistant S. aureus were carried out by using standard procedures. Antibiotic sensitivity profiles were determent by breakpoint dilution method. Out of 222 S. aureus isolation, 139 (62.61%) were isolated from the diabetic foot and 83 (37.39%) from the nasal carriage. Seventy one (30.87%) of the patients were S. aureus infection diabetic foot with nasal carriage. Among diabetic foot infection and nasal carriage patients, 40.85% of S. aureus were considered as methicillin resistant S. aureus. Rifampicin (96.40%) and Levofloxacin (91.44%) were active against S. aureus. Patients at strong risk for methicillin resistant S. aureus nasal carriage and subsequent diabetic foot infection with high resistance to antibiotics. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Variant innate immune responses of mammary epithelial cells to challenge by Staphylococcus aureus, Escherichia coli and the regulating effect of taurine on these bioprocesses.

    Science.gov (United States)

    Zheng, Liuhai; Xu, Yuanyuan; Lu, Jinye; Liu, Ming; Bin Dai; Miao, Jinfeng; Yin, Yulong

    2016-07-01

    Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) are important pathogens causing subclinical and clinical bovine mastitis, respectively. Taurine, an organic acid found in animal tissues, has been used for the treatment of various superficial infections and chronic inflammations. We challenged a bovine mammary epithelial cell (MEC) line (MAC-T) or a mouse mammary epithelial cell line (EpH4-Ev) with either E. coli or S. aureus and compared the responses of MECs to these 2 pathogens. We also examined the regulatory effects of taurine on these responses. Receptor analyses showed that both TLR2 and TLR4 are upregulated upon exposure to either E. coli or S. aureus. Taurine pre-treatment dampened upregulation to some extent. E. coli and S. aureus stimulated comparable levels of ROS, which could be inhibited by taurine pre-treatment. E. coli infection elicited a dramatic change in iNOS expression. Taurine significantly decreased iNOS expression in the S. aureus challenged group. Protein microarray demonstrated that 32/40 and 8/40 inflammatory molecules/mediators were increased after E. coli or S. aureus challenge, respectively. The fold changes of most molecules were higher in the E. coli infection group than that in the S. aureus infection group. Taurine negatively regulated the inflammatory profile in both bacterial infections. Pro-inflammatory cytokines (such as TNF-α) connected with TLR activation were down-regulated by taurine pre-treatment. The influence of TAK-242 and OxPAPC on cytokine/molecule expression profiles to E. coli challenge are different than to S. aureus. Some important factors (MyD88, TNF-α, IL-1β, iNOS and IL-6) mediated by TLR activation were suppressed either in protein microarray or special assay (PCR/kits) or both. TAK-242 restrained ROS production and NAGase activity similar to the effect of taurine in E. coli challenge groups. The detection of 3 indices (T-AOC, SOD and MDA) reflecting oxidative stress in vivo, showed that

  9. Short communication: Antimicrobial efficacy of intramammary treatment with a novel biphenomycin compound against Staphylococcus aureus, Streptococcus uberis, and Escherichia coli-induced mouse mastitis.

    Science.gov (United States)

    Demon, Dieter; Breyne, Koen; Schiffer, Guido; Meyer, Evelyne

    2013-01-01

    Bovine mastitis undermines udder health, jeopardizes milk production, and entails prohibitive costs, estimated at $2 billion per year in the dairy industry of the United States. Despite intensive research, the dairy industry has not managed to eradicate the 3 major bovine mastitis-inducing pathogens: Staphylococcus aureus, Streptococcus uberis, and Escherichia coli. In this study, the antimicrobial efficacy of a newly formulated biphenomycin compound (AIC102827) was assessed against intramammary Staph. aureus, Strep. uberis, and E. coli infections, using an experimental mouse mastitis model. Based on its effective and protective doses, AIC102827 applied into the mammary gland was most efficient to treat Staph. aureus, but also adequately reduced growth of Strep. uberis or E. coli, indicating its potential as a broad-spectrum candidate to treat staphylococcal, streptococcal, and coliform mastitis in dairy cattle. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  10. METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS (MRSA ...

    African Journals Online (AJOL)

    Nosocomial infections caused by methicillin-resistant strains of Staphylococcus aureus often pose therapeutic dilemma to the clinicians because of the multi resistant nature of these strains of Staphylococcus aureus. Outbreaks of both nosocomial and community acquired infections are also frequent and difficult to control.

  11. Next-Generation Sequence Analysis Reveals Transfer of Methicillin Resistance to a Methicillin-Susceptible Staphylococcus aureus Strain That Subsequently Caused a Methicillin-Resistant Staphylococcus aureus Outbreak: a Descriptive Study.

    Science.gov (United States)

    Weterings, Veronica; Bosch, Thijs; Witteveen, Sandra; Landman, Fabian; Schouls, Leo; Kluytmans, Jan

    2017-09-01

    Resistance to methicillin in Staphylococcus aureus is caused primarily by the mecA gene, which is carried on a mobile genetic element, the staphylococcal cassette chromosome mec (SCC mec ). Horizontal transfer of this element is supposed to be an important factor in the emergence of new clones of methicillin-resistant Staphylococcus aureus (MRSA) but has been rarely observed in real time. In 2012, an outbreak occurred involving a health care worker (HCW) and three patients, all carrying a fusidic acid-resistant MRSA strain. The husband of the HCW was screened for MRSA carriage, but only a methicillin-susceptible S. aureus (MSSA) strain, which was also resistant to fusidic acid, was detected. Multiple-locus variable-number tandem-repeat analysis (MLVA) typing showed that both the MSSA and MRSA isolates were MT4053-MC0005. This finding led to the hypothesis that the MSSA strain acquired the SCC mec and subsequently caused an outbreak. To support this hypothesis, next-generation sequencing of the MSSA and MRSA isolates was performed. This study showed that the MSSA isolate clustered closely with the outbreak isolates based on whole-genome multilocus sequence typing and single-nucleotide polymorphism (SNP) analysis, with a genetic distance of 17 genes and 44 SNPs, respectively. Remarkably, there were relatively large differences in the mobile genetic elements in strains within and between individuals. The limited genetic distance between the MSSA and MRSA isolates in combination with a clear epidemiologic link supports the hypothesis that the MSSA isolate acquired a SCC mec and that the resulting MRSA strain caused an outbreak. Copyright © 2017 American Society for Microbiology.

  12. A pig model of acute Staphylococcus aureus induced pyemia

    DEFF Research Database (Denmark)

    Nielsen, O. L.; Iburg, T.; Aalbæk, B.

    2009-01-01

    Background: Sepsis caused by Staphylococcus aureus constitutes an important cause of morbidity and mortality in humans, and the incidence of this disease-entity is increasing. In this paper we describe the initial microbial dynamics and lesions in pigs experimentally infected with S. aureus....... aureus isolated from man and an extension of the timeframe aiming at inducing sepsis, severe sepsis and septic shock....

  13. Concomitant infection of Neospora caninum and Bovine Herpesvirus type 5 in spontaneous bovine abortions

    Directory of Open Access Journals (Sweden)

    Maia S. Marin

    2013-11-01

    Full Text Available Bovine Herpesvirus type 5 (BoHV-5 has not been conclusively demonstrated to cause bovine abortion. Brain lesions produced by Neospora caninum and Bovine Herpesvirus type 1 (BoHV-1 exhibit common features. Therefore, careful microscopic evaluation and additional diagnostic procedures are required to achieve an accurate final etiological diagnosis. The aim of the present work was to investigate the occurrence of infections due to BoHV-1, BoHV-5 and N. caninum in 68 cases of spontaneous bovine abortions which showed microscopic lesions in the fetal central nervous system. This study allowed the identification of 4 (5.9% fetuses with dual infection by BoHV-5 and N. caninum and 33 (48.5% cases in which N. caninum was the sole pathogen identified. All cases were negative to BoHV-1. The results of this study provide evidence that dual infection by BoHV-5 and N. caninum occur during pregnancy in cattle; however, the role of BoHV-5 as a primary cause of bovine abortion needs further research. Molecular diagnosis of BoHV-5 and N. caninum confirmed the importance of applying complementary assays to improve the sensitivity of diagnosing bovine abortion.

  14. Community-acquired necrotizing pneumonia caused by methicillin-resistant Staphylococcus aureus ST30-SCCmecIVc-spat019-PVL positive in San Antonio de Areco, Argentina

    Directory of Open Access Journals (Sweden)

    Silvina Fernández

    2015-03-01

    Full Text Available Community-acquired methicillin-resistant Staphylococcus aureus is the first cause of skin and soft tissue infections, but can also produce severe diseases such as bacteremia, osteomyelitis and necrotizing pneumonia. Some S. aureus lineages have been described in cases of necrotizing pneumonia worldwide, usually in young, previously healthy patients. In this work, we describe a fatal case of necrotizing pneumonia due to community-acquired methicillin-resistant S. aureus clone ST30-SCCmecIVc-spat019-PVL positive in an immunocompetent adult patient.

  15. Geographic distribution of Staphylococcus aureus causing invasive infections in Europe: a molecular-epidemiological analysis.

    Directory of Open Access Journals (Sweden)

    Hajo Grundmann

    2010-01-01

    Full Text Available Staphylococcus aureus is one of the most important human pathogens and methicillin-resistant variants (MRSAs are a major cause of hospital and community-acquired infection. We aimed to map the geographic distribution of the dominant clones that cause invasive infections in Europe.In each country, staphylococcal reference laboratories secured the participation of a sufficient number of hospital laboratories to achieve national geo-demographic representation. Participating laboratories collected successive methicillin-susceptible (MSSA and MRSA isolates from patients with invasive S. aureus infection using an agreed protocol. All isolates were sent to the respective national reference laboratories and characterised by quality-controlled sequence typing of the variable region of the staphylococcal spa gene (spa typing, and data were uploaded to a central database. Relevant genetic and phenotypic information was assembled for interactive interrogation by a purpose-built Web-based mapping application. Between September 2006 and February 2007, 357 laboratories serving 450 hospitals in 26 countries collected 2,890 MSSA and MRSA isolates from patients with invasive S. aureus infection. A wide geographical distribution of spa types was found with some prevalent in all European countries. MSSA were more diverse than MRSA. Genetic diversity of MRSA differed considerably between countries with dominant MRSA spa types forming distinctive geographical clusters. We provide evidence that a network approach consisting of decentralised typing and visualisation of aggregated data using an interactive mapping tool can provide important information on the dynamics of MRSA populations such as early signalling of emerging strains, cross border spread, and importation by travel.In contrast to MSSA, MRSA spa types have a predominantly regional distribution in Europe. This finding is indicative of the selection and spread of a limited number of clones within health care

  16. Porcine models of non-bacterial thrombotic endocarditis (NBTE) and infective endocarditis (IE) caused by Staphylococcus aureus: a preliminary study.

    Science.gov (United States)

    Christiansen, Johanna G; Jensen, Henrik E; Johansen, Louise K; Kochl, Janne; Koch, Jørgen; Aalbaek, Bent; Nielsen, Ole L; Leifsson, Páll S

    2013-05-01

    Non-bacterial thrombotic endocarditis (NBTE) and, in particular, infective endocarditis (IE), are serious and potentially life-threatening diseases. An increasingly important agent of human IE is Staphylococcus aureus, which typically causes an acute endocarditis with high mortality. The study aim was to evaluate the pig as a model for non-bacterial as well as S. aureus-associated endocarditis, as these models would have several advantages compared to other laboratory animal models. Fourteen animals underwent surgery with placement of a plastic catheter in the left side of the heart. Six of the pigs did not receive a bacterial inoculation and were used to study the development of NBTE. The remaining eight pigs were inoculated intravenously once or twice with S. aureus, 10(5)-10(7) cfu/kg body weight. Two bacterial strains were used: S54F9 (porcine) and NCTC8325-4 (human). Clinical examination, echocardiography and bacterial blood cultures were used to diagnose and monitor the development of endocarditis. Animals were euthanized at between two and 15 days after catheter placement, and tissue samples were collected for bacteriology and histopathology. Pigs inoculated with 10(7) cfu/kg of S. aureus strain S54F9 developed clinical, echocardiographic and pathologic signs of IE. All other pigs, except one, developed NBTE. Serial blood cultures withdrawn after inoculation were positive in animals with IE, and negative in all other animals. S. aureus endocarditis was successfully induced in pigs with an indwelling cardiac catheter after intravenous inoculation of 10(7) cfu/kg of S. aureus strain S54F9. The model simulates typical pathological, clinical and diagnostic features seen in the human disease. Furthermore, NBTE was induced in all but one of the pigs without IE. Thus, the pig model can be used in future studies of the pathogenesis, diagnosis and therapy of NBTE and S. aureus endocarditis.

  17. Staphylococcus aureus and healthcare-associated infections

    NARCIS (Netherlands)

    Ekkelenkamp, M.B.

    2011-01-01

    Many medical procedures breach or suppress patients’ natural defences, leaving them vulnerable to infections which would not occur in healthy humans: “healthcare-associated infections”. Healthcare-associated infections caused by the bacterium Staphylococcus aureus (S. aureus) are probably the most

  18. Mild Staphylococcus aureus Skin Infection Improves the Course of Subsequent Endogenous S. aureus Bacteremia in Mice.

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    Sanne van den Berg

    Full Text Available Staphylococcus aureus carriers with S. aureus bacteremia may have a reduced mortality risk compared to non-carriers. A role for the immune system is suggested. Here, we study in mice the effect of mild S. aureus skin infection prior to endogenous or exogenous S. aureus bacteremia, and evaluate protection in relation to anti-staphylococcal antibody levels. Skin infections once or twice by a clinical S. aureus isolate (isolate P or S. aureus strain 8325-4 were induced in mice free of S. aureus and anti-staphylococcal antibodies. Five weeks later, immunoglobulin G (IgG levels in blood against 25 S. aureus antigens were determined, and LD50 or LD100 bacteremia caused by S. aureus isolate P was induced. S. aureus skin infections led to elevated levels of anti-staphylococcal IgG in blood. One skin infection improved the course of subsequent severe endogenous bacteremia only. A second skin infection further improved animal survival rate, which was associated with increased pre-bacteremia IgG levels against Efb, IsaA, LukD, LukE, Nuc, PrsA and WTA. In conclusion, S. aureus isolate P skin infection in mice reduces the severity of subsequent endogenous S. aureus bacteremia only. Although cellular immune effects cannot be rules out, anti-staphylococcal IgG against specified antigens may contribute to this effect.

  19. Methicillin-resistant Staphylococcus aureus associated with animals and its relevance to human health

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    Annalisa ePantosti

    2012-04-01

    Full Text Available Staphylococcus aureus is a typical human pathogen. Some animal S. aureus lineages have derived from human strains following profound genetic adaptation determining a change in host specificity. Due to the close relationship of animals with the environmental microbioma and resistoma, animal staphylococcal strains also represent a source of resistance determinants. Methicillin-resistant S. aureus (MRSA emerged fifty years ago as a nosocomial pathogen but in the last decade it has also become a frequent cause of infections in the community. The recent finding that MRSA frequently colonizes animals, especially livestock, has been a reason for concern, as it has revealed an expanded reservoir of MRSA. While MRSA strains recovered from companion animals are generally similar to human nosocomial MRSA, MRSA strains recovered from food animals appear to be specific animal-adapted clones. Since 2005, MRSA belonging to ST398 was recognized as a colonizer of pigs and human subjects professionally exposed to pig farming. The pig MRSA was also found to colonize other species of farmed animals, including horses, cattle and poultry and was therefore designated livestock-associated (LA-MRSA. LA-MRSA ST398 can cause infections in humans in contact with animals, and can infect hospitalized people, although at the moment this occurrence is relatively rare. Other animal-adapted MRSA clones have been detected in livestock, such as ST1 and ST9. Recently, ST130 MRSA isolated from bovine mastitis has been found to carry a novel mecA gene that eludes detection by conventional PCR tests. Similar ST130 strains have been isolated from human infections in UK, Denmark and Germany at low frequency. It is plausible that the increased attention to animal MRSA will reveal other strains with peculiar characteristics that can pose a risk to human health.

  20. Staphylococcus aureus Central Nervous System Infections in Children.

    Science.gov (United States)

    Vallejo, Jesus G; Cain, Alexandra N; Mason, Edward O; Kaplan, Sheldon L; Hultén, Kristina G

    2017-10-01

    Central nervous system (CNS) infections caused by Staphylococcus aureus are uncommon in pediatric patients. We review the epidemiology, clinical features and treatment in 68 patients with a S. aureus CNS infection evaluated at Texas Children's Hospital. Cases of CNS infection in children with positive cerebrospinal fluid cultures or spinal epidural abscess (SEA) for S. aureus at Texas Children's Hospital from 2001 to 2013 were reviewed. Seventy cases of S. aureus CNS infection occurred in 68 patients. Forty-nine cases (70%) were secondary to a CNS device, 5 (7.1%) were postoperative meningitis, 9 (12.8%) were hematogenous meningitis and 7 (10%) were SEAs. Forty-seven (67.2%) were caused by methicillin-sensitive S. aureus (MSSA) and 23 (32.8%) by methicillin-resistant S. aureus (MRSA). Community-acquired infections were more often caused by MRSA that was clone USA300/pvl. Most patients were treated with nafcillin (MSSA) or vancomycin (MRSA) with or without rifampin. Among patients with MRSA infection, 50% had a serum vancomycin trough obtained with the median level being 10.6 μg/mL (range: 5.4-15.7 μg/mL). Only 1 death was associated with S. aureus infection. The epidemiology of invasive of S. aureus infections continues to evolve with MSSA accounting for most of the infections in this series. The majority of cases were associated with neurosurgical procedures; however, hematogenous S. aureus meningitis and SEA occurred as community-acquired infections in patients without predisposing factors. Patients with MRSA CNS infections had a favorable response to vancomycin, but the beneficial effect of combination therapy or targeting vancomycin trough concentrations of 15-20 μg/mL remains unclear.

  1. Latent class analysis of the diagnostic characteristics of PCR and conventional bacteriological culture in diagnosing intramammary infections caused by Staphylococcus aureus in dairy cows at dry off

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    Cederlöf Sara Ellinor

    2012-11-01

    Full Text Available Abstract Background Staphylococcus aureus is one of the most common causes of intramammary infections in dairy cows at dry off. Reliable identification is important for disease management on herd level and for antimicrobial treatment of infected animals. Our objective was to evaluate the test characteristics of PathoProof ™ Mastitis PCR Assay and bacteriological culture (BC in diagnosing bovine intramammary infections caused by S. aureus at dry off at different PCR cycle threshold (Ct-value cut-offs. Methods Sterile quarter samples and non-sterile composite samples from 140 animals in seven herds were collected in connection with the dairy herd improvement (DHI milk recording. All quarter samples were analyzed using BC whereas all composite samples were analyzed with PathoProof ™ Mastitis PCR Assay. Latent class analysis was used to estimate test properties for PCR and BC in the absence of a perfect reference test. The population was divided into two geographically divided subpopulations and the Hui-Walter 2-test 2-populations model applied to estimate Se, Sp for the two tests, and prevalence for the two subpopulations. Results The Se for PCR increased with increasing Ct-value cut-off, accompanied by a small decrease in Sp. For BC the Se decreased and Sp increased with increasing Ct-value cut-off. Most optimal test estimates for the real-time PCR assay were at a Ct-value cut-off of 37; 0.93 [95% posterior probability interval (PPI 0.60-0.99] for Se and 0.95 [95% PPI 0.95-0.99] for Sp. At the same Ct-value cut-off, Se and Sp for BC were 0.83 [95% PPI 0.66-0.99] and 0.97 [95% PPI 0.91-0.99] respectively. Depending on the chosen PCR Ct-value cut-off, the prevalence in the subpopulations varied; the prevalence increased with increasing PCR Ct-value cut-offs. Conclusion Neither BC nor real-time PCR is a perfect test in detecting IMI in dairy cows at dry off. The changes in sensitivity and prevalence at different Ct-value cut-offs for both PCR and

  2. Presence of Classical Enterotoxin Genes, agr Typing, Antimicrobial Resistance, and Genetic Diversity of Staphylococcus aureus from Milk of Cows with Mastitis in Southern Brazil.

    Science.gov (United States)

    Kroning, Isabela S; Iglesias, Mariana A; Mendonça, Karla S; Lopes, Graciela V; Silva, Wladimir P

    2018-05-01

    Staphylococcus aureus is a common causative agent of bovine mastitis in dairy cows and commonly associated with foodborne disease outbreaks. The aim of this study was to evaluate the presence of enterotoxin genes, agr typing, antimicrobial resistance, and genetic diversity of S. aureus isolated from milk of cows with mastitis in dairy farms from southern Brazil. Results showed that 7 (22.6%) of 31 S. aureus isolates were positive for enterotoxin genes. Specifically, the genes encoding for enterotoxins A ( n = 4), C ( n = 2), and B ( n = 1) were detected. Isolates belonging to the agr group III (10 of 31, 32.2%) and agr group I (7 of 31, 22.5%) were the most common. To our knowledge, this is the first report of both agr I and III in the same S. aureus isolate from milk of cows with bovine mastitis. The antimicrobial resistance test showed that 54% of the isolates were multiresistant to antimicrobial agents. The macrorestriction analysis produced 16 different major SmaI pulsed-field gel electrophoresis patterns, with up to two subpatterns. Moreover, the presence of some S. aureus clones in a distinct area was observed. Although this study characterized a limited number of S. aureus isolates, the presence of classical enterotoxin genes and resistance to multiple antimicrobial agents reinforces the importance of this microorganism to animal and human health. In addition, similar genetic profiles have been identified in distinct geographic areas, suggesting clonal dissemination of S. aureus in dairy herds from southern Brazil.

  3. Juxtarenal Modular Aortic Stent Graft Infection Caused by Staphylococcus aureus

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    Róbert Novotný

    2016-01-01

    Full Text Available Introduction. We are presenting a case report of an infected modular abdominal stent graft. Case Presentation. A 67-year-old male patient three years after Cook’s modular abdominal aortic aneurysm (AAA graft implantation for juxtarenal AAA with an implantation of a stent extension into the right common iliac artery for type Ib endoleak. The patient was admitted into our center in severe condition with suspected retroperitoneal bleeding. Computed tomography angiography (CTAG confirmed retroperitoneal bleeding in the right common iliac artery. An urgent surgical revision was indicated; destructed arterial wall around the stent extension in the right common iliac artery was discovered. Due to the severe state of health of the patient, a resection of the infected stent and affected arterial wall was performed, followed by an iliac-femoral crossover bypass. The patient was transported to the intensive care unit with hepatic and renal failure, with maximal catecholamine support. Combined antibiotic treatment was started. The patient died five hours after the procedure. The cause of death was multiorgan failure caused by sepsis. Hemocultures and perioperative microbiological cultures showed the infection agent to be Staphylococcus aureus methicillin sensitive. Conclusion. Stent graft infection is a rare complication. Treatment is associated with high mortality and morbidity.

  4. Glycogen Synthase Kinase 3α Is the Main Isoform That Regulates the Transcription Factors Nuclear Factor-Kappa B and cAMP Response Element Binding in Bovine Endothelial Cells Infected with Staphylococcus aureus

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    Octavio Silva-García

    2018-01-01

    Full Text Available Glycogen synthase kinase 3 (GSK3 is a constitutive enzyme implicated in the regulation of cytokine expression and the inflammatory response during bacterial infections. Mammals have two GSK3 isoforms named GSK3α and GSK3β that plays different but often overlapping functions. Although the role of GSK3β in cytokine regulation during the inflammatory response caused by bacteria is well described, GSK3α has not been found to participate in this process. Therefore, we tested if GSK3α may act as a regulatory isoform in the cytokine expression by bovine endothelial cells infected with Staphylococcus aureus because this bacterium is one of the major pathogens that cause tissue damage associated with inflammatory dysfunction. Interestingly, although both isoforms were phosphorylated–inactivated, we consistently observed a higher phosphorylation of GSK3α at Ser21 than that of GSK3β at Ser9 after bacterial challenge. During a temporal course of infection, we characterized a molecular switch from pro-inflammatory cytokine expression (IL-8, promoted by nuclear factor-kappa B (NF-κB, at an early stage (2 h to an anti-inflammatory cytokine expression (IL-10, promoted by cAMP response element binding (CREB, at a later stage (6 h. We observed an indirect effect of GSK3α activity on NF-κB activation that resulted in a low phosphorylation of CREB at Ser133, a decreased interaction between CREB and the co-activator CREB-binding protein (CBP, and a lower expression level of IL-10. Gene silencing of GSK3α and GSK3β with siRNA indicated that GSK3α knockout promoted the interaction between CREB and CBP that, in turn, increased the expression of IL-10, reduced the interaction of NF-κB with CBP, and reduced the expression of IL-8. These results indicate that GSK3α functions as the primary isoform that regulates the expression of IL-10 in endothelial cells infected with S. aureus.

  5. Technical note: a pilot study using a mouse mastitis model to study differences between bovine associated coagulase-negative staphylococci.

    Science.gov (United States)

    Breyne, K; De Vliegher, S; De Visscher, A; Piepers, S; Meyer, E

    2015-02-01

    Coagulase-negative staphylococci (CNS) are a group of bacteria classified as either minor mastitis pathogens or commensal microbiota. Recent research suggests species- and even strain-related epidemiological and genetic differences within the large CNS group. The current pilot study investigated in 2 experiments whether a mouse mastitis model validated for bovine Staphylococcus aureus can be used to explore further differences between CNS species and strains. In a first dose titration experiment, a low inoculum dose of S. aureus Newbould 305 (positive control) was compared with increasing inoculum doses of a Staphylococcus chromogenes strain originating from a chronic bovine intramammary infection to a sham-inoculated mammary glands (negative control). In contrast to the high bacterial growth following inoculation with S. aureus, S. chromogenes was retrieved in very low levels at 24 h postinduction (p.i.). In a second experiment, the inflammation inflicted by 3 CNS strains was studied in mice. The host immune response induced by the S. chromogenes intramammary strain was compared with the one induced by a Staphylococcus fleurettii strain originating from cow bedding sawdust and by a S. chromogenes strain originating from a teat apex of a heifer. As expected, at 28 and 48 h p.i., low bacterial growth and local neutrophil influx in the mammary gland were induced by all CNS strains. As hypothesized, bacterial growth p.i. was the lowest for S. fleurettii compared with that induced by the 2 S. chromogenes strains, and the overall immune response established by the 3 CNS strains was less pronounced compared with the one induced by S. aureus. Proinflammatory cytokine profiling revealed that S. aureus locally induced IL-6 and IL-1β but not TNF-α, whereas, overall, CNS-inoculated glands lacked a strong cytokine host response but also induced IL-1β locally. Compared with both other CNS strains, S. chromogenes from the teat apex inflicted a more variable IL-1β response

  6. Effect of Coadministration of Vancomycin and BMP-2 on Cocultured Staphylococcus aureus and W-20-17 Mouse Bone Marrow Stromal Cells in Vitro

    Science.gov (United States)

    2012-07-01

    and maintained in Dulbecco’s modified Eagle’s medium (DMEM) with 10% fetal bovine serum (FBS), a 1% antibiotic/antimycotic mixture, 5 ml of L...osteoblastic differen- tiation when cells are challenged with the parasitic S. aureus bac- teria in coculture. ALP-specific activities in the...release of vancomycin and tobramycin from impregnated human and bovine bone grafts. J. Antimicrob. Chemother. 46:423– 428. 48. Younger EM, Chapman MW

  7. Molecular Characterization of Endocarditis-Associated Staphylococcus aureus

    OpenAIRE

    Nethercott, Cara; Mabbett, Amanda N.; Totsika, Makrina; Peters, Paul; Ortiz, Juan C.; Nimmo, Graeme R.; Coombs, Geoffrey W.; Walker, Mark J.; Schembri, Mark A.

    2013-01-01

    Infective endocarditis (IE) is a life-threatening infection of the heart endothelium and valves. Staphylococcus aureus is a predominant cause of severe IE and is frequently associated with infections in health care settings and device-related infections. Multilocus sequence typing (MLST), spa typing, and virulence gene microarrays are frequently used to classify S. aureus clinical isolates. This study examined the utility of these typing tools to investigate S. aureus epidemiology associated ...

  8. Interference of the antimicrobial peptide lactoferricin B with the action of various antibiotics against Escherichia coli and Staphylococcus aureus.

    Science.gov (United States)

    Vorland, L H; Osbakk, S A; Perstølen, T; Ulvatne, H; Rekdal, O; Svendsen, J S; Gutteberg, T J

    1999-01-01

    The antimicrobial peptide, lactoferricin, can be generated upon gastric pepsin cleavage of lactoferrin. We have examined the interaction of lactoferricin of bovine origin, Lf-cin B, with the antibiotics penicillin G, vancomycin, gentamicin, colistin, D-cycloserine and erythromycin against E. coli ATCC 25922 and Staphylococcus aureus ATCC 25923. We demonstrated synergism between Lf-cin B and erythromycin against E. coli, and partial synergism between Lf-cin B and penicillin G, vancomycin and gentamicin against E. coli. Only penicillin G acted in partial synergism with Lf-cin B against S. aureus. Lf-cin B antagonized vancomycin and gentamicin against S. aureus in low concentration. We conclude that Lf-cin B may facilitate the uptake of antibiotics across the cell envelope.

  9. Short communication: ELISA system for screening of bovine mastitis caused by Prototheca zopfii.

    Science.gov (United States)

    Kano, Rui; Sato, Ayano; Sobukawa, Hideto; Sato, Yuko; Ito, Takaaki; Suzuki, Kazuyuki; Hasegawa, Atsuhiko; Kamata, Hiroshi

    2016-08-01

    Prototheca zopfii is an achlorophyllic alga that causes bovine mastitis, resulting in a reduction in milk production and the secretion of thin, watery milk with white flakes. This study evaluated the use of an ELISA system for distinguishing cows with mastitis due to P. zopfii genotype 2 from healthy cows and cows with chronic candidal mastitis. We also investigated the transitional changes of specific antibody titers in healthy cows injected with inactivated P. zopfii genotype 2 cells. The ELISA system exhibited the highest sensitivity (94%) and specificity (100%) for chronic protothecal mastitis when the positive cutoff value was set at 43.4 ELISA units. Anti-protothecal IgG titers were positive in all cows after they were inoculated with inactivated P. zopfii genotype 2 cells. These results indicated that ELISA detection of anti-protothecal IgG in serum provided specificity and sensitivity sufficient for diagnosing protothecal mastitis. Thus, an ELISA system incorporating this specific antiserum is expected to be valuable for definitive field-based diagnosis of bovine mastitis due to P. zopfii genotype 2. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  10. Staphylococcal scalded skin syndrome in a premature newborn caused by methicillin-resistant Staphylococcus aureus: case report

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    Andreas Hörner

    Full Text Available CONTEXT: Staphylococcal scalded skin syndrome is an exfoliative skin disease. Reports of this syndrome in newborns caused by methicillin-resistant Staphylococcus aureus are rare but, when present, rapid diagnosis and treatment is required in order to decrease morbidity and mortality. CASE REPORT: A premature newly born girl weighing 1,520 g, born with a gestational age of 29 weeks and 4 days, developed staphylococcal scalded skin syndrome on the fifth day of life. Cultures on blood samples collected on the first and fourth days were negative, but Pseudomonas aeruginosa and Enterococcus sp. (vancomycin-sensitive developed in blood cultures performed on the day of death (seventh day, and Pseudomonas aeruginosa and Serratia marcescens were identified in cultures on nasopharyngeal, buttock and abdominal secretions. In addition to these two Gram-negative bacilli, methicillin-resistant Staphylococcus aureus was isolated in a culture on the umbilical stump (seventh day. The diagnosis of staphylococcal scalded skin syndrome was based on clinical criteria.

  11. Community-acquired necrotizing pneumonia caused by methicillin-resistant Staphylococcus aureus ST30-SCCmecIVc-spat019-PVL positive in San Antonio de Areco, Argentina.

    Science.gov (United States)

    Fernandez, Silvina; Murzicato, Sofía; Sandoval, Orlando; Fernández-Canigia, Liliana; Mollerach, Marta

    2015-01-01

    Community-acquired methicillin-resistant Staphylococcus aureus is the first cause of skin and soft tissue infections, but can also produce severe diseases such as bacteremia, osteomyelitis and necrotizing pneumonia. Some S. aureus lineages have been described in cases of necrotizing pneumonia worldwide, usually in young, previously healthy patients. In this work, we describe a fatal case of necrotizing pneumonia due to community-acquired methicillin-resistant S. aureus clone ST30-SCCmecIVc-spat019-PVL positive in an immunocompetent adult patient. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. Population structure of Staphylococcus aureus in China

    OpenAIRE

    Yan, Xiaomei

    2015-01-01

    The present PhD research was aimed at analysing the population structure of Staphylococcus aureus in China. Between 2000 and 2005 we found that patients from a single Chinese hospital showed increasing trends in antimicrobial resistance. Among methicillin-resistant S. aureus (MRSA), resistance against rifampicin doubled to 68%. Staphylococcal food poisoning (SFP) is frequent in China. Two predominant S. aureus lineages, ST6 and ST943, were identified causing outbreaks of SFP in Southern China...

  13. Matricaria recutita extract associated with norfloxacin or cephalexin enhances the antimicrobial activity of these drugs against Staphylococcus aureus

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    Rodrigo Rafael Maia

    2017-05-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2017v30n2p25 Emergence of bacterial infections, including those associated with Staphylococcus aureus, brings up a need for searching new and more effective strategies for clinical treatment. The use of medicinal plants associated with conventional antibiotics may represent a therapeutic option. Currently, studies evidence the synergistic effect achieved by combining plant extracts with antibiotics. Our objective was evaluate the in vitro antimicrobial activity and bactericidal kinetics of Matricaria recutita extract (chamomile and its association with cephalexin and norfloxacin on clinical isolates of S. aureus from bovine origin, characterized as resistant. The tests were performed by method of dilution in solid medium to determine the Minimum Inhibitory Concentration (MIC. In both combinations of M. recutita extract with antibiotics norfloxacin and cephalexin, we observed MIC in dilution 1:64, corresponding to 8μg/mL of the antibiotic and 13.43 μg/mL of extract. Cephalexin associated with chamomile extract produced a effect of the combination in 75% of samples in their MIC. The combination of natural products frequently used by the population with the antibiotics tested in this study, could represent a therapeutic option for treatment of infections caused by S. aureus, as well as the prevention of the increasing development of resistance.

  14. Antibacterial and Antioxidant Activities of Liquidambar Orientalis Mill. Various Extracts Against Bacterial Pathogens Causing Mastitis

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    Gülten Ökmen

    2017-08-01

    Full Text Available Antibiotic resistance is being constantly developed worldwide. Coagulase Negative Staphylococci (CNS and Staphylococcus aureus are common causes of bovine subclinical mastitis. Bioactive compound of medicinal plants shows anti-microbial, anti-mutagenic and anti-oxidant effects. The anti-bacterial and anti-oxidant activities of Liquidambar orientalis (L. orientalis extracts on subclinical mastitis causing bacteria in cows have not been reported to date. The aim of the present study was to examine anti-bacterial and anti-oxidant effects of L. orientalis leaf extracts on S. aureus and CNS isolated from cows with subclinical mastitis symptoms. In this study, 3.2 mg/mL minimum inhibitory concentration (MIC of ethanol extracts of L. orientalis has shown to be a most potent anti-bacterial and anti-oxidant for all isolated bacterial species from mastitis cows. In this study, it was investigated anti-bacterial and anti-oxidant potentials of acetone, methanol and ethanol extracts of the L. orientalis. The acetone extract showed maximum inhibition zone against S. aureus numbered 17 (12 mm. In addition to anti-bacterial properties, anti-oxidant activity of L. orientalis extract was examined by ABTS [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid] free radical assay. Trolox was used as a positive control anti-oxidant. Ethanol extract exhibited a strong anti-oxidant activity like Trolox anti-oxidant which was effective at 2.58 mM concentration. Bioactive compounds of sweet gum may be useful to screening mastitis causing bacteria for clinical applications.

  15. 77 FR 29914 - Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products

    Science.gov (United States)

    2012-05-21

    ... Spongiform Encephalopathy; Importation of Bovines and Bovine Products AGENCY: Animal and Plant Health... derived from bovines with regard to bovine spongiform encephalopathy. This action will allow interested... importation of live bovines and products derived from bovines with regard to bovine spongiform encephalopathy...

  16. Genotypic characterisation of Staphylococcus aureus isolates causing bacteraemia at Tygerberg hospital, western cape province, South Africa

    NARCIS (Netherlands)

    Orth, H.; Salaam-Dreyer, Z.; Makgotlho, E.; Sinha, B.; Wasserman, E.

    2011-01-01

    Objectives: There is a paucity of studies on the genotypic characterisation of invasive S. aureus strains and the incidence of communityacquired methicillin resistant S. aureus (CA-MRSA) infections in South Africa. In this study we characterized S. aureus isolates from bacteraemia episodes using

  17. Ceftaroline-Resistant, Daptomycin-Tolerant, and Heterogeneous Vancomycin-Intermediate Methicillin-Resistant Staphylococcus aureus Causing Infective Endocarditis.

    Science.gov (United States)

    Nigo, Masayuki; Diaz, Lorena; Carvajal, Lina P; Tran, Truc T; Rios, Rafael; Panesso, Diana; Garavito, Juan D; Miller, William R; Wanger, Audrey; Weinstock, George; Munita, Jose M; Arias, Cesar A; Chambers, Henry F

    2017-03-01

    We report a case of infective endocarditis (IE) caused by ceftaroline-resistant, daptomycin-tolerant, and heterogeneous vancomycin-intermediate methicillin-resistant S. aureus (MRSA). Resistance to ceftaroline emerged in the absence of drug exposure, and the E447K substitution in the active site of PBP2a previously associated with ceftaroline resistance was identified. Additionally, we present evidence of patient-to-patient transmission of the strain within the same unit. This case illustrates the difficulties in treating MRSA IE in the setting of a multidrug-resistant phenotype. Copyright © 2017 American Society for Microbiology.

  18. Responses to gamma radiation of selected microorganisms in sterile water and bovine muscle

    International Nuclear Information System (INIS)

    Dempster, J.F.; Halls, N.A.

    1986-01-01

    The responses to gamma-radiation of a number of food-associated microorganisms (Staphylococcus aureus, Yersinia enterocolitica, Pseudomonas putrefaciens) were studied in sterile distilled water and sterile bovine muscle slurry. Surviving cells were grown aerobically at room temperature on yeast extract dextrose tryptone agar (PCA, Oxoid). The D 1 0 of the Pseudomonas sp. was 27 Gy in water and the D 1 0 of the Yersinia sp. in water was 32 Gy. In the slurry resistance increased markedly; the Pseudomonas sp. was ten times more resistant (D 1 0 260 Gy) and the Yersinia sp. was seven times more resistant (D 1 0226 Gy). The Staph. aureus was equally sensitive in both systems (author)

  19. [Carriage of Staphylococcus aureus among food service workers].

    Science.gov (United States)

    Alarcón-Lavín, María Paula; Oyarzo, Carolina; Escudero, Carlos; Cerda-Leal, Fabiola; Valenzuela, Francisco J

    2017-12-01

    Background Staphylococcus aureus produces 11 serotypes of endotoxins that may cause food poisoning. Aim To determine the prevalence of type A enterotoxigenic Staphylococcus aureus carriage among food service workers in Chillan, Chile. Material and Methods Pharyngeal swabs were obtained from 100 food service workers and were cultured in Agar plates. After identifying the presence of Staphylococcus aureus, DNA was extracted to identify type A toxin by conventional PCR. Results Thirty eight percent of samples were colonized with Staphylococcus aureus. Among these, 26% were toxin A producers. Conclusions Half of the sampled workers carried Staphylococcus aureus and a quarter of these produced type A enterotoxin.

  20. In vitro antimicrobial activity of Combretum molle (Combretaceae) against Staphylococcus aureus and Streptococcus agalactiae isolated from crossbred dairy cows with clinical mastitis.

    Science.gov (United States)

    Regassa, Fekadu; Araya, Mengistu

    2012-08-01

    Following the rapidly expanding dairy enterprise, mastitis has remained the most economically damaging disease. The objective of this study was mainly to investigate the in vitro antibacterial activities of ethanol extracts of Combretum molle (R.Br.Ex.G.Don) Engl & Diels (Combretaceae) against antibiotic-resistant and susceptible Staphylococcus aureus and Streptococcus agalactiae isolated from clinical cases of bovine mastitis using agar disc diffusion method. The leaf and bark extracts showed antibacterial activity against S. aureus at concentrations of 3 mg/ml while the stem and seed extract did not show any bioactivity. Although both leaf and bark extracts were handled in the same manner, the antibacterial activity of the bark extract against the bacterial strains had declined gradually to a lower level as time advanced after extraction. The leaf extract had sustained bioactivity for longer duration. The susceptibility of the bacteria to the leaf extract is not obviously different between S. aureus and S. agalactiae. Also, there was no difference in susceptibility to the leaf extract between the antibiotic-resistant and antibiotic-sensitive bacteria. Further phytochemical and in vivo efficacy and safety studies are required to evaluate the therapeutic value of the plant against bovine mastitis.

  1. The antibody response in the bovine mammary gland is influenced by the adjuvant and the site of subcutaneous vaccination

    NARCIS (Netherlands)

    Boerhout, Eveline M.; Koets, Ad P.; Mols-Vorstermans, Tanja G.T.; Nuijten, Piet J.M.; Hoeijmakers, Mathieu J.H.; Rutten, Victor P.M.G.; Bijlsma, Jetta J.E.

    2018-01-01

    Intramammary infections in cattle resulting in mastitis have detrimental effects on cows' well-being, lifespan and milk production. In the host defense against S. aureus mastitis antibodies are thought to play an important role. To explore potential ways to increase antibody titers in the bovine

  2. Intra-species diversity and epidemiology varies among coagulase-negative Staphylococcus species causing bovine intramammary infections.

    Science.gov (United States)

    Piessens, V; De Vliegher, S; Verbist, B; Braem, G; Van Nuffel, A; De Vuyst, L; Heyndrickx, M; Van Coillie, E

    2012-02-24

    Although many studies report coagulase-negative staphylococci (CNS) as the predominant cause of subclinical bovine mastitis, their epidemiology is poorly understood. In the current study, the genetic diversity within four CNS species frequently associated with bovine intramammary infections, Staphylococcus haemolyticus, S. simulans, S. chromogenes, and S. epidermidis, was determined. For epidemiological purposes, CNS genotypes recovered from bovine milk collected on six Flemish dairy farms were compared with those from the farm environment, and their distribution within the farms was investigated. Genetic diversity was assessed by two molecular typing techniques, amplification fragment length polymorphism (AFLP) and random amplification of polymorphic DNA (RAPD) analysis. Subtyping revealed the highest genetic heterogeneity among S. haemolyticus isolates. A large variety of genotypes was found among environmental isolates, of which several could be linked with intramammary infection, indicating that the environment could act as a potential source for infection. For S. simulans, various genotypes were found in the environment, but a link with IMI was less obvious. For S. epidermidis and S. chromogenes, genetic heterogeneity was limited and the sporadic isolates from environment displayed largely the same genotypes as those from milk. The higher clonality of the S. epidermidis and S. chromogenes isolates from milk suggests that specific genotypes probably disseminate within herds and are more udder-adapted. Environmental sources and cow-to-cow transmission both seem to be involved in the epidemiology of CNS, although their relative importance might substantially vary between species. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Community-associated methicillin-resistant Staphylococcus aureus causing chronic pneumonia.

    Science.gov (United States)

    Enayet, Iram; Nazeri, Ali; Johnson, Leonard B; Riederer, Kathleen; Pawlak, Joan; Saravolatz, Louis D

    2006-04-01

    A young woman presented with pneumonia of a 3-month duration with predominantly nodular pulmonary infiltrates. Methicillin-resistant Staphylococcus aureus was identified in multiple cultures of sputum specimens. According to findings of pulsed-field gel electrophoresis, the isolate was identical to USA 300 and carried a type IV Staphylococcus cassette chromosome mec type IV gene and the genes for Panton-Valentine leukocidin.

  4. Genotype-specific risk factors for Staphylococcus aureus in Swiss dairy herds with an elevated yield-corrected herd somatic cell count.

    Science.gov (United States)

    Berchtold, B; Bodmer, M; van den Borne, B H P; Reist, M; Graber, H U; Steiner, A; Boss, R; Wohlfender, F

    2014-01-01

    Bovine mastitis is a frequent problem in Swiss dairy herds. One of the main pathogens causing significant economic loss is Staphylococcus aureus. Various Staph. aureus genotypes with different biological properties have been described. Genotype B (GTB) of Staph. aureus was identified as the most contagious and one of the most prevalent strains in Switzerland. The aim of this study was to identify risk factors associated with the herd-level presence of Staph. aureus GTB and Staph. aureus non-GTB in Swiss dairy herds with an elevated yield-corrected herd somatic cell count (YCHSCC). One hundred dairy herds with a mean YCHSCC between 200,000 and 300,000cells/mL in 2010 were recruited and each farm was visited once during milking. A standardized protocol investigating demography, mastitis management, cow husbandry, milking system, and milking routine was completed during the visit. A bulk tank milk (BTM) sample was analyzed by real-time PCR for the presence of Staph. aureus GTB to classify the herds into 2 groups: Staph. aureus GTB-positive and Staph. aureus GTB-negative. Moreover, quarter milk samples were aseptically collected for bacteriological culture from cows with a somatic cell count ≥150,000cells/mL on the last test-day before the visit. The culture results allowed us to allocate the Staph. aureus GTB-negative farms to Staph. aureus non-GTB and Staph. aureus-free groups. Multivariable multinomial logistic regression models were built to identify risk factors associated with the herd-level presence of Staph. aureus GTB and Staph. aureus non-GTB. The prevalence of Staph. aureus GTB herds was 16% (n=16), whereas that of Staph. aureus non-GTB herds was 38% (n=38). Herds that sent lactating cows to seasonal communal pastures had significantly higher odds of being infected with Staph. aureus GTB (odds ratio: 10.2, 95% CI: 1.9-56.6), compared with herds without communal pasturing. Herds that purchased heifers had significantly higher odds of being infected with

  5. Characterization of Enterotoxigenic Bacillus cereus sensu lato and Staphylococcus aureus Isolates and Associated Enterotoxin Production Dynamics in Milk or Meat-Based Broth.

    Science.gov (United States)

    Walker-York-Moore, Laura; Moore, Sean C; Fox, Edward M

    2017-07-15

    Bacillus cereus sensu lato species, as well as Staphylococcus aureus , are important pathogenic bacteria which can cause foodborne illness through the production of enterotoxins. This study characterised enterotoxin genes of these species and examined growth and enterotoxin production dynamics of isolates when grown in milk or meat-based broth. All B. cereus s. l. isolates harboured nheA , hblA and entFM toxin genes, with lower prevalence of bceT and hlyII . When grown at 16 °C, toxin production by individual B. cereus s. l. isolates varied depending on the food matrix; toxin was detected at cell densities below 5 log 10 (CFU/mL). At 16 °C no staphylococcal enterotoxin C (SEC) production was detected by S. aureus isolates, although low levels of SED production was noted. At 30 °C all S. aureus isolates produced detectable enterotoxin in the simulated meat matrix, whereas SEC production was significantly reduced in milk. Relative to B. cereus s. l. toxin production, S. aureus typically required reaching higher cell numbers to produce detectable levels of enterotoxin. Phylogenetic analysis of the sec and sel genes suggested population evolution which correlated with animal host adaptation, with subgroups of bovine isolates or caprine/ovine isolates noted, which were distinct from human isolates. Taken together, this study highlights the marked differences in the production of enterotoxins both associated with different growth matrices themselves, but also in the behaviour of individual strains when exposed to different food matrices.

  6. In silico analysis for identifying potential vaccine candidates against Staphylococcus aureus

    OpenAIRE

    Delfani, Somayeh; Imani Fooladi, Abbas Ali; Mobarez, Ashraf Mohabati; Emaneini, Mohammad; Amani, Jafar; Sedighian, Hamid

    2015-01-01

    Purpose Staphylococcus aureus is one of the most important causes of nosocomial and community-acquired infections. The increasing incidence of multiple antibiotic-resistant S. aureus strains and the emergence of vancomycin resistant S. aureus strains have placed renewed interest on alternative means of prevention and control of infection. S. aureus produces a variety of virulence factors, so a multi-subunit vaccine will be more successful for preventing S. aureus infections than a mono-subuni...

  7. Infectious caused by community-acquired Methicillin-Resistant Staphylococcus aureus (CA-MRSA: three-years experience of an universitary hospital in Rome

    Directory of Open Access Journals (Sweden)

    Anna Altieri

    2010-06-01

    Full Text Available To date methicillin-resistant Staphylococcus aureus (MRSA is one of the most common pathogens causing nosocomial infections(1. In Europe the proportion of MRSA is increasing sharply and the distribution varies from country to country. In recent years there has, in various parts of the world, the emergence of infection with strains of S. aureus methicillin-resistant community-acquired (CA-MRSA than those circulating in hospitals(2. These strains contain a gene that confers resistance to methicillin (mec A SSC mec IV which is usually associated with the gene for Leukocidin Panton Valentine (PVL toxin responsible for necrosis of skin and soft tissue (3. In 2006-2008, at the Laboratory of Bacteriology PolyclinicTor Vergata,were isolated a total of 738 strains of S. aureus from biological samples of different nature (oral, vaginal secretions, wound swab, secreted headset, etc ... of patients related to our surgeries.The identification and study of drug sensitivity of strains were performed with the automatic VITEK2 (bioMérieux. Of the 738 strains of S. aureus identified 212 (28.7% were resistant to methicillin (MRSA, with an increasing trend over the years: 46 isolates, respectively, in 2006, 76 in 2007 and 90 in 2008. The highest frequency of MRSA (varying between 85% and 95% was detected in wound swabs from the dispensary and diabetes (diabetic foot.

  8. Proteases in Escherichia coli and Staphylococcus aureus confer reduced susceptibility to lactoferricin B.

    Science.gov (United States)

    Ulvatne, Hilde; Haukland, Hanne Husom; Samuelsen, Ørjan; Krämer, Manuela; Vorland, Lars H

    2002-10-01

    Lactoferricin B is a cationic antimicrobial peptide derived from the N-terminal part of bovine lactoferrin. The effect of bacterial proteases on the antibacterial activity of lactoferricin B towards Escherichia coli and Staphylococcus aureus was investigated using various protease inhibitors and protease-deficient E. coli mutants. Sodium-EDTA, a metalloprotease inhibitor, was the most efficient inhibitors in both species, but combinations of sodium-EDTA with other types of protease inhibitor gave a synergic effect. The results indicate that several groups of proteases are involved in resistance to lactoferricin B in both E. coli and S. aureus. We also report that genetic inactivation of the heat shock-induced serine protease DegP increased the susceptibility to lactoferricin B in E. coli, suggesting that this protease, at least, is involved in reduced susceptibility to lactoferricin B.

  9. Bovine besnoitiosis emerging in Central-Eastern Europe, Hungary

    OpenAIRE

    Hornok, Sándor; Fedák, András; Baska, Ferenc; Hofmann-Lehmann, Regina; Basso, Walter

    2014-01-01

    BACKGROUND: Besnoitia besnoiti, the cause of bovine besnoitiosis, is a cyst-forming coccidian parasite that has recently been shown to be spreading in several Western and Southern European countries. FINDINGS: Clinical cases of bovine besnoitiosis were confirmed for the first time in Hungary, by histological, serological and PCR analyses. CONCLUSIONS: This is the first report of autochthonous bovine besnoitiosis in Central-Eastern Europe. The emergence of bovine besnoitiosis in this region re...

  10. Staphylococcus aureus bacteraemia in children: a formidable foe ...

    African Journals Online (AJOL)

    Staphylococcus aureus remains one of the most common causes of bacteraemia in children. In order to evade and overcome the immune responses of its host and any antimicrobial therapies aimed at destroying it, this organism, through various mechanisms, continues to evolve. Staphylococcus aureus bacteraemia is a ...

  11. A porcine model of haematogenous brain infectionwith staphylococcus aureus

    DEFF Research Database (Denmark)

    Astrup, Lærke Boye; Agerholm, Jørgen Steen; Nielsen, Ole Lerberg

    2012-01-01

    A PORCINE MODEL OF HAEMATOGENOUS BRAIN INFECTION WITH STAPHYLOCOCCUS AUREUS Astrup Lærke1, Agerholm Jørgen1, Nielsen Ole1, Jensen Henrik1, Leifsson Páll1, Iburg Tine2. 1: Faculty of Health and Medical Sciences, University of Copenhagen, Denmark boye@life.ku.dk 2: National Veterinary Institute......, Uppsala, Sweden Introduction Staphylococcus aureus (S.aureus) is a common cause of sepsis and brain abscesses in man and a frequent cause of porcine pyaemia. Here we present a porcine model of haematogenous S. aureus-induced brain infection. Materials and Methods Four pigs had two intravenous catheters...... thromboemboli (two pigs). The venous catheter was used for blood sampling before, during and after inoculation. The pigs were euthanized either 24 or 48 hours after inoculation. The brains were collected and examined histologically. Results We describe unifocal suppurative encephalitis 48 hours after...

  12. Characterization of methicillin-resistant Staphylococcus aureus Sequence Type 398

    DEFF Research Database (Denmark)

    Christiansen, Mette Theilgaard

    Staphylococcus aureus is an opportunistic pathogen that colonizes the nares and skin surfaces of several animal species, including man. S. aureus can cause a wide variety of infections ranging from superficial soft tissue and skin infections to severe and deadly systemic infections. Traditionally S....... aureus and methicillin-resistant Staphylococcus aureus (MRSA) have been associated with hospitals, but during the past decades MRSA has emerged in the community and now a new branch of MRSA has been found in association with livestock (LA-MRSA). A specific lineage (multilocus sequence type 398 (ST398...

  13. Research advance in rapid detection of foodborne Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Xihong Zhao

    2016-09-01

    Full Text Available Staphylococcus aureus is a gram-positive, coccus-shaped facultative anaerobe and a member of the Staphylococcaceae family. In recent years, alimentary toxicosis caused by S. aureus is a very serious problem worldwide, which constitutes a great threat to public health. In this review, we tried to summarize the conventional methods and newly developed rapid detection techniques of S. aureus (traditional detection method, biochemical detection, immunology method, molecular biology, and biosensor method for their principles, advantages, disadvantages, and applications. Furthermore, the future perspectives of S. aureus detection methods were forecasted at last.

  14. Invasive Staphylococcus aureus infection in an African adolescent ...

    African Journals Online (AJOL)

    Staphylococcus aureus remains an important cause of mortality, in the community and health care set-ups. S. aureus strains with genes encoding lethal toxins and culture negative sepsis augment the diagnostic challenge in resource limited settings. With a growing rate of resistance to the causative bacteria and atypical ...

  15. Proposal for agar disk diffusion interpretive criteria for susceptibility testing of bovine mastitis pathogens using cefoperazone 30μg disks.

    Science.gov (United States)

    Feßler, Andrea T; Kaspar, Heike; Lindeman, Cynthia J; Peters, Thomas; Watts, Jeffrey L; Schwarz, Stefan

    2017-02-01

    Cefoperazone is a third generation cephalosporin which is commonly used for bovine mastitis therapy. Bacterial pathogens involved in bovine mastitis are frequently tested for their susceptibility to cefoperazone. So far, the cefoperazone susceptibility testing using 30μg disks has been hampered by the lack of quality control (QC) ranges as well as the lack of interpretive criteria. In 2014, QC ranges for 30 μg cefoperazone disks have been established for Staphylococcus aureus ATCC ® 25923 and Escherichia coli ATCC ® 25922. As a next step, interpretive criteria for the susceptibility testing of bovine mastitis pathogens should be developed. For this, 637 bovine mastitis pathogens (including 112 S. aureus, 121 coagulase-negative staphylococci (CoNS), 103 E. coli, 101 Streptococcus agalactiae, 100 Streptococcus dysgalactiae and 100 Streptococcus uberis) were investigated by agar disk diffusion according to the document Vet01-A4 of the Clinical and Laboratory Standards Institute (CLSI) using 30μg cefoperazone disks and the results were compared to the corresponding MIC values as determined by broth microdilution also according to the aforementioned CLSI document. Based on the results obtained and taking into account the achievable milk concentration of cefoperazone after regular dosing, the following interpretive criteria were proposed as a guidance for mastitis diagnostic laboratories: for staphylococci and E. coli ≥23mm (susceptible), 18-22mm (intermediate) and ≤17mm (resistant) and for streptococci ≥18mm (susceptible), and ≤17mm (non-susceptible). These proposed interpretive criteria shall contribute to a harmonization of cefoperazone susceptibility testing of bovine mastitis pathogens. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Research advance in rapid detection of foodborne Staphylococcus aureus

    OpenAIRE

    Xihong Zhao; Caijiao Wei; Junliang Zhong; Shiwei Jin

    2016-01-01

    Staphylococcus aureus is a gram-positive, coccus-shaped facultative anaerobe and a member of the Staphylococcaceae family. In recent years, alimentary toxicosis caused by S. aureus is a very serious problem worldwide, which constitutes a great threat to public health. In this review, we tried to summarize the conventional methods and newly developed rapid detection techniques of S. aureus (traditional detection method, biochemical detection, immunology method, molecular biology, and biosensor...

  17. Staphylococcal aureus Enterotoxin C and Enterotoxin-Like L Associated with Post-partum Mastitis

    DEFF Research Database (Denmark)

    Franck, Kristina T; Gumpert, Heidi; Olesen, Bente

    2017-01-01

    between isolates from the two outbreaks revealed a S. aureus pathogenicity island containing enterotoxin C and enterotoxin-like L only in isolates from outbreak 2. Enterotoxin C and enterotoxin-like L carrying S. aureus are associated with bovine mastitis and our findings indicate that these may also...... PVL and ACME negative. In outbreak 1, the isolates harbored SCCmec IVa and in outbreak 2 SCCmec V. The clinical presentation differed between the two outbreaks, as none of five MRSA positive mothers in outbreak 1 had mastitis vs. five of six MRSA positive mothers in outbreak 2 (p ....02). To investigate if whole-genome sequencing could identify virulence genes associated with mastitis, t015:ST45 isolates from Denmark (N = 101) were whole-genome sequenced. Sequence analysis confirmed two separate outbreaks with no sign of sustained spread into the community. Analysis of the accessory genome...

  18. Antimicrobial and Barrier Properties of Bovine Gelatin Films Reinforced by Nano TiO2

    Directory of Open Access Journals (Sweden)

    R. Nassiri

    2013-11-01

    Full Text Available The effects of nano titanium dioxide incorporation were investigated on the water vaporpermeability, oxygen permeability, and antimicrobial properties of bovine gelatin films. The nano TiO2 (TiO2-N was homogenized by sonication and incorporated into bovine gelatin solutions at different concentrations(e.g. 1, 2, 3, and 5% w/w of dried gelatin. The permeability of the films to water vapor and oxygen wassignificantly decreased by incorporating of low concentration TiO2-N to gelatin solutions. TiO2-N gelatin filmsshowed an excellent antimicrobial activity against Staphylococcus aureus and Escherichia coli. Theseproperties suggest that TiO2-N has the potential as filler in gelatin-based films for using as an active packagingmaterials in pharmaceutical and food packaging industries.

  19. Near-drowning-associated pneumonia with bacteremia caused by coinfection with methicillin-susceptible Staphylococcus aureus and Edwardsiella tarda in a healthy white man: a case report.

    Science.gov (United States)

    Zambon, Lucas Santos; Marta, Guilherme Nader; Chehter, Natan; Del Nero, Luis Guilherme; Cavallaro, Marina Costa

    2016-07-16

    Edwardsiella tarda is an Enterobacteriaceae found in aquatic environments. Extraintestinal infections caused by Edwardsiella tarda in humans are rare and occur in the presence of some risk factors. As far as we know, this is the first case of near-drowning-associated pneumonia with bacteremia caused by coinfection with methicillin-susceptible Staphylococcus aureus and Edwardsiella tarda in a healthy patient. A 27-year-old previously healthy white man had an episode of fresh water drowning after acute alcohol consumption. Edwardsiella tarda and methicillin-sensitive Staphylococcus aureus were isolated in both tracheal aspirate cultures and blood cultures. This case shows that Edwardsiella tarda is an important pathogen in near drowning even in healthy individuals, and not only in the presence of risk factors, as previously known.

  20. Staphylococcus aureus enterotoxins A- and B

    DEFF Research Database (Denmark)

    Danielsen, E Michael; Hansen, Gert H; Karlsdóttir, Edda

    2013-01-01

    Enterotoxins of Staphylococcus aureus are among the most common causes of food poisoning. Acting as superantigens they intoxicate the organism by causing a massive uncontrolled T cell activation that ultimately may lead to toxic shock and death. In contrast to our detailed knowledge regarding...

  1. Synthesis and characterization of bovine femur bone hydroxyapatite containing silver nanoparticles for the biomedical applications

    International Nuclear Information System (INIS)

    Nirmala, R.; Sheikh, Faheem A.; Kanjwal, Muzafar A.; Lee, John Hwa; Park, Soo-Jin; Navamathavan, R.; Kim, Hak Yong

    2011-01-01

    Bovine femur bone hydroxyapatite (HA) containing silver (Ag) nanoparticles was synthesized by thermal decomposition method and subsequent reduction of silver nitrate with N,N-dimethylformamide (DMF) in the presence of poly(vinylacetate) (PVAc). The structural, morphological, and chemical properties of the HA–Ag nanoparticles were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). TEM images showed that the Ag nanoparticles with size ranging from 8 to 20 nm and were arranged at the periphery of HA crystals. Bactericidal activity of HA–Ag with different concentration of Ag nanoparticles immobilized on the surface of HA was investigated against gram-positive Staphylococcus aureus (S. aureus, non-MRSA), Methicillin resistant S. aureus (MRSA) and gram-negative Escherichia coli (E.coli) by the disc diffusion susceptibility test. The HA–Ag nanoparticles showed that broad spectrum activity against non-MRSA, MRSA, and E. coli bacterial strains.

  2. Bovine TLR2 and TLR4 mediate Cryptosporidium parvum recognition in bovine intestinal epithelial cells.

    Science.gov (United States)

    Yang, Zhengtao; Fu, Yunhe; Gong, Pengtao; Zheng, Jingtong; Liu, Li; Yu, Yuqiang; Li, Jianhua; Li, He; Yang, Ju; Zhang, Xichen

    2015-08-01

    Cryptosporidium parvum (C. parvum) is an intestinal parasite that causes diarrhea in neonatal calves. It results in significant morbidity of neonatal calves and economic losses for producers worldwide. Innate resistance against C. parvum is thought to depend on engagement of pattern recognition receptors. However, the role of innate responses to C. parvum has not been elucidated in bovine. The aim of this study was to evaluate the role of TLRs in host-cell responses during C. parvum infection of cultured bovine intestinal epithelial cells. The expressions of TLRs in bovine intestinal epithelial cells were detected by qRT-PCR. To determine which, if any, TLRs may play a role in the response of bovine intestinal epithelial cells to C. parvum, the cells were stimulated with C. parvum and the expression of TLRs were tested by qRT-PCR. The expression of NF-κB was detected by western blotting. Further analyses were carried out in bovine TLRs transfected HEK293 cells and by TLRs-DN transfected bovine intestinal epithelial cells. The results showed that bovine intestinal epithelial cells expressed all known TLRs. The expression of TLR2 and TLR4 were up-regulated when bovine intestinal epithelial cells were treated with C. parvum. Meanwhile, C. parvum induced IL-8 production in TLR2 or TLR4/MD-2 transfected HEK293 cells. Moreover, C. parvum induced NF-κB activation and cytokine expression in bovine intestinal epithelial cells. The induction of NF-κB activation and cytokine expression by C. parvum were reduced in TLR2-DN and TLR4-DN transfected cells. The results showed that bovine intestinal epithelial cells expressed all known TLRs, and bovine intestinal epithelial cells recognized and responded to C. parvum via TLR2 and TLR4. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Brain infection following experimental Staphylococcus aureus sepsis in pigs

    DEFF Research Database (Denmark)

    Astrup, Lærke Boye; Iburg, Tine Moesgaard; Nielsen, Ole Lerberg

    2010-01-01

    Introduction: Sepsis is a major problem in humans and both the incidence and mortality is increasing. Multiple microabcesses can be found in the brain of septic patients. Staphylococcus aureus is one of the most common causes of sepsis and brain abscesses. S. aureus is also a frequent cause...... of spontaneous porcine pyemia including endocarditis and associated brain lesions. We present a porcine model of haematogenous S. aureus induced brain infection. Materials and Methods: Twelve pigs received an intravenous injection of S. aureus of 108 CFU/kg body weight once at 0h or twice at 0h and 12h. Four...... pigs were kept as controls. The pigs were euthanized in groups of four at either 6, 12, 24 or 48 h post infection. The brain was collected from all the animals and examined histologically. Results: All the inoculated pigs developed sepsis and 7 out of 12 animals had microabscesses in the prosencephalon...

  4. Genetic diversity of Staphylococcus aureus in Buruli ulcer.

    Directory of Open Access Journals (Sweden)

    Nana Ama Amissah

    2015-02-01

    Full Text Available Buruli ulcer (BU is a necrotizing skin disease caused by Mycobacterium ulcerans. Previous studies have shown that wounds of BU patients are colonized with M. ulcerans and several other microorganisms, including Staphylococcus aureus, which may interfere with wound healing. The present study was therefore aimed at investigating the diversity and topography of S. aureus colonizing BU patients during treatment.We investigated the presence, diversity, and spatio-temporal distribution of S. aureus in 30 confirmed BU patients from Ghana during treatment. S. aureus was isolated from nose and wound swabs, and by replica plating of wound dressings collected bi-weekly from patients. S. aureus isolates were characterized by multiple-locus variable number tandem repeat fingerprinting (MLVF and spa-typing, and antibiotic susceptibility was tested.Nineteen (63% of the 30 BU patients tested positive for S. aureus at least once during the sampling period, yielding 407 S. aureus isolates. Detailed analysis of 91 isolates grouped these isolates into 13 MLVF clusters and 13 spa-types. Five (26% S. aureus-positive BU patients carried the same S. aureus genotype in their anterior nares and wounds. S. aureus isolates from the wounds of seven (37% patients were distributed over two different MLVF clusters. Wounds of three (16% patients were colonized with isolates belonging to two different genotypes at the same time, and five (26% patients were colonized with different S. aureus types over time. Five (17% of the 30 included BU patients tested positive for methicillin-resistant S. aureus (MRSA.The present study showed that the wounds of many BU patients were contaminated with S. aureus, and that many BU patients from the different communities carried the same S. aureus genotype during treatment. This calls for improved wound care and hygiene.

  5. Genetic diversity of Staphylococcus aureus in Buruli ulcer.

    Science.gov (United States)

    Amissah, Nana Ama; Glasner, Corinna; Ablordey, Anthony; Tetteh, Caitlin S; Kotey, Nana Konama; Prah, Isaac; van der Werf, Tjip S; Rossen, John W; van Dijl, Jan Maarten; Stienstra, Ymkje

    2015-02-01

    Buruli ulcer (BU) is a necrotizing skin disease caused by Mycobacterium ulcerans. Previous studies have shown that wounds of BU patients are colonized with M. ulcerans and several other microorganisms, including Staphylococcus aureus, which may interfere with wound healing. The present study was therefore aimed at investigating the diversity and topography of S. aureus colonizing BU patients during treatment. We investigated the presence, diversity, and spatio-temporal distribution of S. aureus in 30 confirmed BU patients from Ghana during treatment. S. aureus was isolated from nose and wound swabs, and by replica plating of wound dressings collected bi-weekly from patients. S. aureus isolates were characterized by multiple-locus variable number tandem repeat fingerprinting (MLVF) and spa-typing, and antibiotic susceptibility was tested. Nineteen (63%) of the 30 BU patients tested positive for S. aureus at least once during the sampling period, yielding 407 S. aureus isolates. Detailed analysis of 91 isolates grouped these isolates into 13 MLVF clusters and 13 spa-types. Five (26%) S. aureus-positive BU patients carried the same S. aureus genotype in their anterior nares and wounds. S. aureus isolates from the wounds of seven (37%) patients were distributed over two different MLVF clusters. Wounds of three (16%) patients were colonized with isolates belonging to two different genotypes at the same time, and five (26%) patients were colonized with different S. aureus types over time. Five (17%) of the 30 included BU patients tested positive for methicillin-resistant S. aureus (MRSA). The present study showed that the wounds of many BU patients were contaminated with S. aureus, and that many BU patients from the different communities carried the same S. aureus genotype during treatment. This calls for improved wound care and hygiene.

  6. A 3-year long study of Staphylococcus aureus isolates from subclinical mastitis in three Azawak zebu herds at the Sahelian experimental farm of Toukounous, Niger.

    Science.gov (United States)

    Issa, Abdoulkarim Ibrahim; Duprez, Jean-Noël; Bada-Alambedji, Rianatou; Djika, Mamane; Mainil, Jacques Georges; Bardiau, Marjorie

    2016-02-01

    Staphylococcus (S.) aureus is one of the most important pathogens causing bovine mastitis. The aim of the present work was to follow in three herds and during the 3 years the clonality of S. aureus isolated from California Mastitis Test (CMT)-positive cows at the experimental station of Toukounous (Niger) by (i) comparing their pulsed field gel electrophoresis (PFGE) fingerprints, (ii) identifying their virulotypes by PCR amplification and (iii) assessing the production of capsule and the formation of biofilm. The 88 S. aureus isolates belonged to 14 different pulsotypes, 3 of them being predominant: A (30 %), D (27 %), B (15 %). A and B pulsotypes had the highest profile similarity coefficient (94 %), while others had similarity coefficients under 60 %. Seventy-five S. aureus isolates were further studied for their virulotypes, capsular antigens and biofilm production. Most surface factor-, leukocidin- and haemolysin-, but not the enterotoxin-encoding genes were detected in the majority (>75 %) of the isolates and were evenly distributed between the A, B and D pulsotype isolates. The majority of the 72 S. aureus positive with the cap5H or cap8H PCR produced the CP5 (82 %) or the CP8 (88 %) capsular antigen, respectively. Biofilm production by the 57 icaA-positive isolates was strong for 8 isolates, moderate for 31 isolates but weak for 18 isolates, implying that the icaA gene may not be expressed in vitro by one third of the positive isolates. Similar to other studies, those results confirm that a restricted number of S. aureus clones circulate within the three herds at Toukounous and that their specific virulence-associated properties must still be further studied.

  7. Detecting Staphylococcus aureus in milk from dairy cows using sniffer dogs.

    Science.gov (United States)

    Fischer-Tenhagen, C; Theby, V; Krömker, V; Heuwieser, W

    2018-05-01

    Fast and accurate identification of disease-causing pathogens is essential for specific antimicrobial therapy in human and veterinary medicine. In these experiments, dogs were trained to identify Staphylococcus aureus and differentiate it from other common mastitis-causing pathogens by smell. Headspaces from agar plates, inoculated raw milk samples, or field samples collected from cows with Staphylococcus aureus and other mastitis-causing pathogens were used for training and testing. The ability to learn the specific odor of Staphylococcus aureus in milk depended on the concentration of the pathogens in the training samples. Sensitivity and specificity for identifying Staphylococcus aureus were 91.3 and 97.9%, respectively, for pathogens grown on agar plates; 83.8 and 98.0% for pathogens inoculated in raw milk; and 59.0 and 93.2% for milk samples from mastitic cows. The results of these experiments underline the potential of odor detection as a diagnostic tool for pathogen diagnosis. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  8. Necrotizing Pneumonia Caused by Panton-Valentine Leucocidin-Producing Staphylococcus aureus Originating from a Bartholin's Abscess

    Directory of Open Access Journals (Sweden)

    N. Jung

    2008-01-01

    Full Text Available Background. Panton-Valentine leukocidin (PVL-producing Staphylococcus aureus is emerging as a serious problem worldwide. There has been an increase in the incidence of necrotizing lung infections in otherwise healthy young people with a very high mortality associated with these strains. Sporadic severe infectious complications after incision of Bartholin's abcesses have been described but involvement of S. aureus is rare. Case report. We present a 23-year-old apparently healthy female patient without any typical predisposing findings who developed severe sepsis with necrotizing pneumonia and multiple abscesses following incision of a Bartholin's abscess. Methicillin-sensitive S. aureus harbouring Panton-Valentine leucocidin genes were cultured from the abscess fluid, multiple blood cultures and a postoperative wound swab. Aggressive antibiotic therapy with flucloxacillin, rifampicin and clindamycin, drainage and intensive supportive care lead finally to recovery. Conclusions. S. aureus, in particular PVL-positive strains, should be considered when a young, immunocompetent person develops a fulminant necrotizing pneumonia. Minor infections—such as Bartholin's abscess—can precede this life-threating syndrome. Bactericidal antistaphylococcal antibiotics are recommended for treatment, and surgical procedures may become necessary.

  9. A retrospective analysis of the infectious bovine rhinotracheitis (bovine herpes virus-1) surveillance program in Norway using Monte Carlo simulation models

    DEFF Research Database (Denmark)

    Paisley, Larry; Tharaldsen, J.; Jarp, J.

    2001-01-01

    Serological surveillance for antibodies against bovine herpes virus type I (BHV-1) which causes infectious bovine rhinotracheitis and infectious pustular vulvovaginitis has been carried out since 1992 in Norway. Since 1993 (when a single infected herd was detected) all bulk-milk and pooled...

  10. Detection and identification of Staphylococcus aureus in raw milk by ...

    African Journals Online (AJOL)

    Staphylococcus aureus causes foodborne diseases if consumed in contaminated milk products. Rapid detection and characterization of foodborne pathogen S. aureus is crucial for epidemiological investigations and food safety surveillance. It is still a challenge to detect and identify bacterial pathogens quickly and ...

  11. Selective biosensing of Staphylococcus aureus using chitosan quantum dots

    Science.gov (United States)

    Abdelhamid, Hani Nasser; Wu, Hui-Fen

    2018-01-01

    Selective biosensing of Staphylococcus aureus (S. aureus) using chitosan modified quantum dots (CTS@CdS QDs) in the presence of hydrogen peroxide is reported. The method is based on the intrinsic positive catalase activity of S. aureus. CTS@CdS quantum dots provide high dispersion in aqueous media with high fluorescence emission. Staphylococcus aureus causes a selective quenching of the fluorescence emission of CTS@CdS QDs in the presence of H2O2 compared to other pathogens such as Escherichia coli and Pseudomonas aeruginosa. The intrinsic enzymatic character of S. aureus (catalase positive) offers selective and fast biosensing. The present method is highly selective for positive catalase species and requires no expensive reagents such as antibodies, aptamers or microbeads. It could be extended for other species that are positive catalase.

  12. Construction and application of a bovine immune-endocrine cDNA microarray.

    Science.gov (United States)

    Tao, Wenjing; Mallard, Bonnie; Karrow, Niel; Bridle, Byram

    2004-09-01

    A variety of commercial DNA arrays specific for humans and rodents are widely available; however, microarrays containing well-characterized genes to study pathway-specific gene expression are not as accessible for domestic animals, such as cattle, sheep and pigs. Therefore, a small-scale application-targeted bovine immune-endocrine cDNA array was developed to evaluate genetic pathways involved in the immune-endocrine axis of cattle during periods of altered homeostasis provoked by physiological or environmental stressors, such as infection, vaccination or disease. For this purpose, 167 cDNA sequences corresponding to immune, endocrine and inflammatory response genes were collected and categorized. Positive controls included 5 housekeeping genes (glyceraldehydes-3-phosphate dehydrogenase, hypoxanthine phosphoribosyltransferase, ribosomal protein L19, beta-actin, beta2-microglobulin) and bovine genomic DNA. Negative controls were a bacterial gene (Rhodococcus equi 17-kDa virulence-associated protein) and a partial sequence of the plasmid pACYC177. In addition, RNA extracted from un-stimulated, as well as superantigen (Staphylococcus aureus enterotoxin-A, S. aureus Cowan Pansorbin Cells) and mitogen-stimulated (LPS, ConA) bovine blood leukocytes was mixed, reverse transcribed and PCR amplified using gene-specific primers. The endocrine-associated genes were amplified from cDNA derived from un-stimulated bovine hypothalamus, pituitary, adrenal and thyroid gland tissues. The array was constructed in 4 repeating grids of 180 duplicated spots by coupling the PCR amplified 213-630 bp gene fragments onto poly-l-lysine coated glass slides. The bovine immune-endocrine arrays were standardized and preliminary gene expression profiles generated using Cy3 and Cy5 labelled cDNA from un-stimulated and ConA (5 microg/ml) stimulated PBMC of 4 healthy Holstein cows (2-4 replicate arrays/cow) in a time course study. Mononuclear cell-derived cytokine and chemokine (IL-2, IL-1alpha

  13. Staphylococcus aureus small colony variants in diabetic foot infections

    Directory of Open Access Journals (Sweden)

    Estrella Cervantes-García

    2015-03-01

    Full Text Available Background: Staphylococcus aureus (S. aureus is one of the major pathogens causing chronic infections. The ability of S. aureus to acquire resistance to a diverse range of antimicrobial compounds results in limited treatment options, particularly in methicillin-resistant S. aureus (MRSA. A mechanism by which S. aureus develops reduced susceptibility to antimicrobials is through the formation of small colony variants (SCVs. Infections by SCVs of S. aureus are an upcoming problem due to difficulties in laboratory diagnosis and resistance to antimicrobial therapy. Methods: A prospective study was performed on 120 patients diagnosed with both type 2 diabetes mellitus and infected diabetic foot ulcers. The study was carried out from July 2012 to December 2013 in Hospital General de Mexico. The samples were cultured in blood agar, mannitol salt agar, and MacConkey agar media, and incubated at 37°C in aerobic conditions. Results: We describe the first known cases of diabetic foot infections caused by MRSA-SCVs in patients diagnosed with type 2 diabetes mellitus and infected diabetic foot ulcers. In all of our cases, the patients had not received any form of gentamicin therapy. Conclusions: The antibiotic therapy commonly used in diabetic patients with infected diabetic foot ulcers fails in the case of MRSA-SCVs because the intracellular location protects S. aureus-SCVs from the host's defenses and also helps them resist antibiotics. The cases studied in this article add to the spectrum of persistent and relapsing infections attributed to MRSA-SCVs and emphasizes that these variants may also play a relevant role in diabetic foot infections.

  14. Staphylococcus aureus-induced G2/M phase transition delay in host epithelial cells increases bacterial infective efficiency.

    Directory of Open Access Journals (Sweden)

    Ludmila Alekseeva

    Full Text Available Staphylococcus aureus is a highly versatile, opportunistic pathogen and the etiological agent of a wide range of infections in humans and warm-blooded animals. The epithelial surface is its principal site of colonization and infection. In this work, we investigated the cytopathic effect of S. aureus strains from human and animal origins and their ability to affect the host cell cycle in human HeLa and bovine MAC-T epithelial cell lines. S. aureus invasion slowed down cell proliferation and induced a cytopathic effect, resulting in the enlargement of host cells. A dramatic decrease in the number of mitotic cells was observed in the infected cultures. Flow cytometry analysis revealed an S. aureus-induced delay in the G2/M phase transition in synchronous HeLa cells. This delay required the presence of live S. aureus since the addition of the heat-killed bacteria did not alter the cell cycle. The results of Western blot experiments showed that the G2/M transition delay was associated with the accumulation of inactive cyclin-dependent kinase Cdk1, a key inducer of mitosis entry, and with the accumulation of unphosphorylated histone H3, which was correlated with a reduction of the mitotic cell number. Analysis of S. aureus proliferation in asynchronous, G1- and G2-phase-enriched HeLa cells showed that the G2 phase was preferential for bacterial infective efficiency, suggesting that the G2 phase delay may be used by S. aureus for propagation within the host. Taken together, our results divulge the potential of S. aureus in the subversion of key cellular processes such as cell cycle progression, and shed light on the biological significance of S. aureus-induced host cell cycle alteration.

  15. Virulence potential of Staphylococcus aureus isolates from Buruli ulcer patients

    NARCIS (Netherlands)

    Amissah, Nana Ama; Chlebowicz, Monika A.; Ablordey, Anthony; Tetteh, Caitlin S.; Prah, Isaac; van der Werf, Tjip S.; Friedrich, Alex W.; van Dijl, Jan Maarten; Stienstra, Ymkje; Rossen, John W.

    Buruli ulcer (BU) is a necrotizing infection of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. BU wounds may also be colonized with other microorganisms including Staphylococcus aureus. This study aimed to characterize the virulence factors of S. aureus isolated from BU patients.

  16. Efficacy of florfenicol for treatment of clinical and subclinical bovine mastitis.

    Science.gov (United States)

    Wilson, D J; Sears, P M; Gonzalez, R N; Smith, B S; Schulte, H F; Bennett, G J; Das, H H; Johnson, C K

    1996-04-01

    To evaluate efficacy of florfenicol treatment for bovine mastitis caused by Streptococcus agalactiae, Staphylococcus aureus nonagalactiae streptococci, coagulase-negative staphylococci, Escherichia coli, Klebsiella sp, and others. Double blind study with cases randomly assigned to 1 of 2 treatment groups. 861 cows/10 commercial dairy farms. Experimental (750 mg of florfenicol) or control (200 mg of cloxacillin) treatment was administered by intramammary infusion every 12 hours for 3 treatment to all cases. Treatments were randomly assigned identified only by numerical labels. To retain blinding, the longer withdrawal time was adhered to for all cases. Cases remained in the study only if there was no other treatment. Quarter samples were recultured 14, 21, and 28 days later. If all samples after day 1 were culture negative, the case was defined as cured. If only 1 of the follow-up results was positive, the case was considered cured if the day-28 somatic cell count was mastitis treatment regimens poor efficacy may be partly attributable to the short duration of treatment.

  17. Identification of the ClpX Regulon in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Jelsbak, Lotte; Thomsen, Line Elnif; Ingmer, Hanne

    Staphyloccous aureus is a major human pathogen capable of causing a wide spectrum of infections ranging from superficial wound infections to life-threatening endocarditis and toxic shock syndrome. Essential for S. aureus virulence is a large number of cell-surface-associated proteins and secreted...... we show here that almost 400 genes (15%) are influenced by the clpX deletion. Furthermore, ClpX not only regulates many virulence factors, but rather serves as a global regulator of central functions for S. aureus lifestyle and pathogenicity....

  18. Effect of essential oils of Syzygium aromaticum and Cinnamomum zeylanicum and their major components on biofilm production in Staphylococcus aureus strains isolated from milk of cows with mastitis.

    Science.gov (United States)

    Budri, P E; Silva, N C C; Bonsaglia, E C R; Fernandes Júnior, A; Araújo Júnior, J P; Doyama, J T; Gonçalves, J L; Santos, M V; Fitzgerald-Hughes, D; Rall, V L M

    2015-09-01

    Bovine mastitis is an inflammation of the mammary glands of cows and causes significant economic losses in dairy cattle. Staphylococcus aureus is one of the microorganisms most commonly isolated. Novel agents are required in agricultural industries to prevent the development of mastitis. The production of biofilm by Staph. aureus facilitates the adhesion of bacteria to solid surfaces and contributes to the transmission and maintenance of these bacteria. The effect of the essential oils of Syzygium aromaticum (clove; EOSA) and Cinnamomum zeylanicum (cinnamon; EOCZ) and their major components, eugenol and cinnamaldehyde, on Staph. aureus biofilm formation on different surfaces was investigated. The results showed a significant inhibition of biofilm production by EOSA on polystyrene and stainless steel surfaces (69.4 and 63.6%, respectively). However, its major component, eugenol, was less effective on polystyrene and stainless steel (52.8 and 19.6%, respectively). Both EOCZ and its major component, cinnamaldehyde, significantly reduced biofilm formation on polystyrene (74.7 and 69.6%, respectively) and on stainless steel surfaces (45.3 and 44.9%, respectively). These findings suggest that EOSA, EOCZ, and cinnamaldehyde may be considered for applications such as sanitization in the food industry. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  19. Unraveling the dynamics of community-associated methicillin-resistant Staphylococcus aureus

    NARCIS (Netherlands)

    Bootsma, M.C.; Bonten, M.J.M.

    2013-01-01

    Since the first description of the community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strain USA300 [1] in the 1990s, this pathogen has emerged worldwide [2]. Within a decade, USA300 has become the most prevalent cause of community-acquired S. aureus infections in many

  20. Distribution of capsular and surface polysaccharide serotypes of Staphylococcus aureus

    NARCIS (Netherlands)

    von Eiff, Christof; Taylor, Kimberly L; Mellmann, Alexander; Fattom, Ali I; Friedrich, Alexander W.; Peters, Georg; Becker, Karsten

    Because of its ability to cause serious and fatal infections, Staphylococcus aureus remains one of the most feared microorganisms. Methicillin-resistant S. aureus (MRSA) has long been a common pathogen in healthcare facilities, but within the past decade, it has emerged as a problematic pathogen in

  1. Lysionotin attenuates Staphylococcus aureus pathogenicity by inhibiting α-toxin expression.

    Science.gov (United States)

    Teng, Zihao; Shi, Dongxue; Liu, Huanyu; Shen, Ziying; Zha, Yonghong; Li, Wenhua; Deng, Xuming; Wang, Jianfeng

    2017-09-01

    α-Toxin, one of the best known pore-forming proteins produced by Staphylococcus aureus (S. aureus), is a critical virulence factor in multiple infections. The necessity of α-toxin for S. aureus pathogenicity suggests that this toxin is an important target for the development of a potential treatment strategy. In this study, we showed that lysionotin, a natural compound, can inhibit the hemolytic activity of culture supernatants by S. aureus by reducing α-toxin expression. Using real-time PCR analysis, we showed that transcription of hla (the gene encoding α-toxin) and agr (the locus regulating hla) was significantly inhibited by lysionotin. Lactate dehydrogenase and live/dead assays indicated that lysionotin effectively protected human alveolar epithelial cells against S. aureus, and in vivo studies also demonstrated that lysionotin can protect mice from pneumonia caused by S. aureus. These findings suggest that lysionotin is an efficient inhibitor of α-toxin expression and shows significant protection against S. aureus in vitro and in vivo. This study supports a potential strategy for the treatment of S. aureus infection by inhibiting the expression of virulence factors and indicates that lysionotin may be a potential treatment for S. aureus pneumonia.

  2. Molecular Characterization of Methicillin-Resistant Staphylococcus aureus Causing Fatal Purulent Pericarditis.

    Science.gov (United States)

    Kumar, Vasudevan Anil; Nair, Nisha; Thachathodiyl, Rajesh; Nandakumar, Aswathy; Dinesh, Kavitha R; Thatcher, Eileen; Karim, Shamsul; Biswas, Raja

    2013-07-01

    Though pericardial disease is common in patients with renal disease, purulent pericarditis is very rare. We report a fatal case of purulent pericarditis and sepsis due to methicillin-resistant Staphylococcus aureus in a 78-year-old male with systemic hypertension and renal disease along with the molecular characterization of its resistant mechanism.

  3. Antimicrobial Mechanisms of Macrophages and the Immune Evasion Strategies of Staphylococcus aureus

    Science.gov (United States)

    Flannagan, Ronald S.; Heit, Bryan; Heinrichs, David E.

    2015-01-01

    Habitually professional phagocytes, including macrophages, eradicate microbial invaders from the human body without overt signs of infection. Despite this, there exist select bacteria that are professional pathogens, causing significant morbidity and mortality across the globe and Staphylococcus aureus is no exception. S. aureus is a highly successful pathogen that can infect virtually every tissue that comprises the human body causing a broad spectrum of diseases. The profound pathogenic capacity of S. aureus can be attributed, in part, to its ability to elaborate a profusion of bacterial effectors that circumvent host immunity. Macrophages are important professional phagocytes that contribute to both the innate and adaptive immune response, however from in vitro and in vivo studies, it is evident that they fail to eradicate S. aureus. This review provides an overview of the antimicrobial mechanisms employed by macrophages to combat bacteria and describes the immune evasion strategies and some representative effectors that enable S. aureus to evade macrophage-mediated killing. PMID:26633519

  4. Prevalence of coagulase-positive staphylococci, other than Staphylococcus aureus, in bovine mastitis.

    Science.gov (United States)

    Roberson, J R; Fox, L K; Hancock, D D; Gay, J M; Besser, T E

    1996-01-01

    To determine prevalence and relevance of coagulase-positive Staphylococcus hyicus and S intermedius intramammary infections (IMI) in dairy cows and determine the ability of the 4-hour tube coagulase (TC) test to differentiate the coagulase-positive staphylococci (CPS). Prevalence of CPS was determined for primiparous cows (point prevalence and prevalence at first parturition) and multiparous cows (point prevalence) of 2 herd groups: 10% CPS IMI prevalence = high prevalence (HP). For prevalence, cows of 22 dairy herds. For TC, 1,038 CPS strains isolated from cow milk. Speciation of CPS from aseptically collected composite milk samples was performed. Coagulase-positive isolates from 4 cow groups were tested for their ability to coagulate rabbit plasma by 4 hours: LP and HP primiparous cows at parturition, and LP and HP cows any time after first parturition. Of 487 CPS in the prevalence study, 82.1% were S aureus, 17.7% were coagulase-positive S hyicus, and 0.2% were S intermedius. Of all CPS IMI in LP herds, 34% were coagulase-positive S hyicus; of all CPS IMI in HP herds, 9% were coagulase-positive S hyicus. Coagulase-positive S hyicus appeared to persist to the end of lactation in 4 cows (mean linear somatic cell count = 3.7). The TC test was > or = 97% sensitive, < or = 33% specific, and had a predictive value positive range of 60 to 97% for S aureus isolates. Coagulase-positive S hyicus appears capable of inducing chronic, low-grade IMI. Staphylococcus intermedius does not appear to be an important mastitis pathogen. The TC test is not valid to use as the sole method to differentiate CPS species.

  5. Resistance of Causing Bacteria of Bovine Mastitis in Regard to Common Antimicrobials

    Directory of Open Access Journals (Sweden)

    Darío Martínez Pacheco

    2013-05-01

    Full Text Available The bacteria develop resistence against to the common antimicrobians, which is a limitant in the control and treatment of infectious diseases. In the sistems of production of bovine milk, one problem that affects the quantity and quality of the produced milk, is the mastitis, which in most cases has a bacterian origen. Addition to correct milking routine is used many antibacterial agents that for pharmacokinetics and pharmacodynamics reasons are the first selection for this disease. Some cases the use of antibacterial agents is effective, while in other cases do not, due to the development of bacterial resistence. Recently, it has been possible to identify different mechanisms of resistence developed by bacteria. This has allowed pharmacology researchers to create new drugs or to modify existing, seeking to decrease the inefficacy caused by the mutation of the bacteria as an adaptative response mechanism. Therefore,the objective of this review is to offer an updated document on resistance mechanisms identified.

  6. Dialysis catheter-related septicaemia--focus on Staphylococcus aureus septicaemia

    DEFF Research Database (Denmark)

    Nielsen, J; Ladefoged, S D; Kolmos, H J

    1998-01-01

    BACKGROUND: Dialysis catheters are a common cause of nosocomial septicaemia in haemodialysis units usually due to staphylococci, of which Staphylococcus aureus is the most pathogenic. In this study, the epidemiology and pathogenesis of dialysis catheter-related infections were studied, and methods...... to infection were measured. After catheter insertion, all patients were screened for nasal carriage of S. aureus, and a culture was taken from the skin overlying the catheter insertion site. Once a week, cultures were taken from the insertion site and from the hub, and aerobic and anaerobic blood cultures were...... drawn from the catheter. If clinical signs of septicaemia occurred, peripheral blood cultures were also performed, when it was possible. RESULTS: The incidence of septicaemia was 49% (21/43) in patients, and 56% of all cases were caused by S. aureus. The mortality was 14% (3/21) and the incidence...

  7. Whole-genome sequencing of bloodstream Staphylococcus aureus isolates does not distinguish bacteraemia from endocarditis

    DEFF Research Database (Denmark)

    Lilje, Berit; Rasmussen, Rasmus Vedby; Dahl, Anders

    2017-01-01

    Most Staphylococcus aureus isolates can cause invasive disease given the right circumstances, but it is unknown if some isolates are more likely to cause severe infections than others. S. aureus bloodstream isolates from 120 patients with definite infective endocarditis and 121 with S. aureus...... bacteraemia without infective endocarditis underwent whole-genome sequencing. Genome-wide association analysis was performed using a variety of bioinformatics approaches including SNP analysis, accessory genome analysis and k-mer based analysis. Core and accessory genome analyses found no association...... with either of the two clinical groups. In this study, the genome sequences of S. aureus bloodstream isolates did not discriminate between bacteraemia and infective endocarditis. Based on our study and the current literature, it is not convincing that a specific S. aureus genotype is clearly associated...

  8. Evaluation of Approaches to Monitor Staphylococcus aureus Virulence Factor Expression during Human Disease

    OpenAIRE

    Rozemeijer, Wouter; Fink, Pamela; Rojas, Eduardo; Jones, C. Hal; Pavliakova, Danka; Giardina, Peter; Murphy, Ellen; Liberator, Paul; Jiang, Qin; Girgenti, Douglas; Peters, Remco P. H.; Savelkoul, Paul H. M.; Jansen, Kathrin U.; Anderson, Annaliesa S.; Kluytmans, Jan

    2015-01-01

    Staphylococcus aureus is a versatile pathogen of medical significance, using multiple virulence factors to cause disease. A prophylactic S. aureus 4-antigen (SA4Ag) vaccine comprising capsular polysaccharide (types 5 and 8) conjugates, clumping factor A (ClfA) and manganese transporter C (MntC) is under development. This study was designed to characterize S. aureus isolates recovered from infected patients and also to investigate approaches for examining expression of S. aureus vaccine candid...

  9. Methicillin resistant staphylococci associated with bovine mastitis and their zoonotic importance

    Directory of Open Access Journals (Sweden)

    S. Vishnupriya

    2014-06-01

    Full Text Available Aim: The present study was conducted to determine the zoonotic importance of methicillin resistant staphylococci associated with bovine mastitis and their potential role in transmission to animal handlers. Materials and Methods: A total of 158 milk samples from bovine mastitis cases and 126 nasal swabs from the animal handlers were sampled in and around Pondicherry (Southern India. The Presence of Staphylococcal organism was confirmed by PCR amplification using the genus specific primers and among the isolated Staphylococci; methicillin resistance was identified by genetic amplification of mec A methicillin resistant gene. Then the amplified gene from the bacteria expressing the mecA gene (PBP2a (~2kb fragment was further sequenced using four sets of primer pairs and aligned for determining their genetic relatedness between the sequences. Both phenotypic and genotypic analysis was carried out for the six MRS isolates (three bovine and three human in this study. Results: Out of 158 mastitis milk samples; 96 and 19 bovine isolates were found to be positive for Staphylococcal genus specific PCR and methicillin resistant (mecA gene PCR, respectively. Similarly, Out of 126 human nasal swabs, 64 and 13 human isolates were found to be positive for Staphylococcal genus specific PCR and mec A gene PCR, respectively. Among the 160 staphylococcal isolates (Bovine and Human origin; 51 were identified as coagulase-positive staphylococci (CPS and remaining as coagulase-negative staphylococci (CONS. The results obtained in this study revealed the presence of many species of Staphylococci but the predominant species were Staphylococcus aureus and S. epidermidis. The Sequence analysis of the mec A gene of human isolates obtained in this study had a maximum identity (99% -100% with the bovine isolates. Conclusion: The phenotypic and genotypic analysis carried out for the six MRS (Methicillin Resistant Staphylococci isolates in this study were indistinguishable

  10. Staphylococcus aureus: methicillin-susceptible S. aureus to methicillin-resistant S. aureus and vancomycin-resistant S. aureus.

    Science.gov (United States)

    Rehm, Susan J; Tice, Alan

    2010-09-15

    The evolution of methicillin-resistant and vancomycin-resistant Staphylococcus aureus has demanded serious review of antimicrobial use and development of new agents and revised approaches to prevent and overcome drug resistance. Depending on local conditions and patient risk factors, empirical therapy of suspected S. aureus infection may require coverage of drug-resistant organisms with newer agents and novel antibiotic combinations. The question of treatment with inappropriate antibiotics raises grave concerns with regard to methicillin-resistant S. aureus selection, overgrowth, and increased virulence. Several strategies to reduce the nosocomial burden of resistance are suggested, including shortened hospital stays and outpatient parenteral antimicrobial therapy of the most serious infections.

  11. Molecular Characterization of Endocarditis-Associated Staphylococcus aureus

    Science.gov (United States)

    Nethercott, Cara; Mabbett, Amanda N.; Totsika, Makrina; Peters, Paul; Ortiz, Juan C.; Nimmo, Graeme R.; Coombs, Geoffrey W.

    2013-01-01

    Infective endocarditis (IE) is a life-threatening infection of the heart endothelium and valves. Staphylococcus aureus is a predominant cause of severe IE and is frequently associated with infections in health care settings and device-related infections. Multilocus sequence typing (MLST), spa typing, and virulence gene microarrays are frequently used to classify S. aureus clinical isolates. This study examined the utility of these typing tools to investigate S. aureus epidemiology associated with IE. Ninety-seven S. aureus isolates were collected from patients diagnosed with (i) IE, (ii) bloodstream infection related to medical devices, (iii) bloodstream infection not related to medical devices, and (iv) skin or soft-tissue infections. The MLST clonal complex (CC) for each isolate was determined and compared to the CCs of members of the S. aureus population by eBURST analysis. The spa type of all isolates was also determined. A null model was used to determine correlations of IE with CC and spa type. DNA microarray analysis was performed, and a permutational analysis of multivariate variance (PERMANOVA) and principal coordinates analysis were conducted to identify genotypic differences between IE and non-IE strains. CC12, CC20, and spa type t160 were significantly associated with IE S. aureus. A subset of virulence-associated genes and alleles, including genes encoding staphylococcal superantigen-like proteins, fibrinogen-binding protein, and a leukocidin subunit, also significantly correlated with IE isolates. MLST, spa typing, and microarray analysis are promising tools for monitoring S. aureus epidemiology associated with IE. Further research to determine a role for the S. aureus IE-associated virulence genes identified in this study is warranted. PMID:23616460

  12. Molecular characterization of endocarditis-associated Staphylococcus aureus.

    Science.gov (United States)

    Nethercott, Cara; Mabbett, Amanda N; Totsika, Makrina; Peters, Paul; Ortiz, Juan C; Nimmo, Graeme R; Coombs, Geoffrey W; Walker, Mark J; Schembri, Mark A

    2013-07-01

    Infective endocarditis (IE) is a life-threatening infection of the heart endothelium and valves. Staphylococcus aureus is a predominant cause of severe IE and is frequently associated with infections in health care settings and device-related infections. Multilocus sequence typing (MLST), spa typing, and virulence gene microarrays are frequently used to classify S. aureus clinical isolates. This study examined the utility of these typing tools to investigate S. aureus epidemiology associated with IE. Ninety-seven S. aureus isolates were collected from patients diagnosed with (i) IE, (ii) bloodstream infection related to medical devices, (iii) bloodstream infection not related to medical devices, and (iv) skin or soft-tissue infections. The MLST clonal complex (CC) for each isolate was determined and compared to the CCs of members of the S. aureus population by eBURST analysis. The spa type of all isolates was also determined. A null model was used to determine correlations of IE with CC and spa type. DNA microarray analysis was performed, and a permutational analysis of multivariate variance (PERMANOVA) and principal coordinates analysis were conducted to identify genotypic differences between IE and non-IE strains. CC12, CC20, and spa type t160 were significantly associated with IE S. aureus. A subset of virulence-associated genes and alleles, including genes encoding staphylococcal superantigen-like proteins, fibrinogen-binding protein, and a leukocidin subunit, also significantly correlated with IE isolates. MLST, spa typing, and microarray analysis are promising tools for monitoring S. aureus epidemiology associated with IE. Further research to determine a role for the S. aureus IE-associated virulence genes identified in this study is warranted.

  13. Duplex Identification of Staphylococcus aureus by Aptamer and Gold Nanoparticles.

    Science.gov (United States)

    Chang, Tianjun; Wang, Libo; Zhao, Kexu; Ge, Yu; He, Meng; Li, Gang

    2016-06-01

    Staphylococcus aureus is the top common pathogen causing infections and food poisoning. Identification of S. aureus is crucial for the disease diagnosis and regulation of food hygiene. Herein, we report an aptamer-AuNPs based method for duplex identification of S. aureus. Using AuNPs as an indicator, SA23, an aptamer against S. aureus, can well identify its target from Escherichia coli, Listeria monocytogenes and Pseudomonas aeruginosa. Furthermore, we find citrate-coated AuNPs can strongly bind to S. aureus, but not bind to Salmonella enterica and Proteus mirabilis, which leads to different color changes in salt solution. This colorimetric response is capable of distinguishing S. aureus from S. enteritidis and P. mirabilis. Thus, using the aptasensor and AuNPs together, S. aureus can be accurately identified from the common pathogens. This duplex identification system is a promising platform for simple visual identification of S. aureus. Additionally, in the aptasensing process, bacteria are incubated with aptamers and then be removed before the aptamers adding to AuNPs, which may avoid the interactions between bacteria and AuNPs. This strategy can be potentially applied in principle to detect other cells by AuNPs-based aptasensors.

  14. Outbreak of bullous impetigo caused by Staphylococcus aureus strains of phage type 3C/71 in a maternity ward linked to nasal carriage of a healthcare worker.

    Science.gov (United States)

    Piechowicz, Lidia; Garbacz, Katarzyna; Budzyńska, Anna; Dąbrowska-Szponar, Maria

    2012-01-01

    We describe an outbreak of bullous impetigo (BI) that occurred in a maternity unit and show phenotypic and genotypic properties and relatedness of isolated Staphylococcus aureus strains. Clinical material was obtained from 11 affected neonates. Additionally, nasal swabs from 67 healthy care workers (HCWs) as well as 107 environmental swabs were investigated. All isolates were screened for exfoliative toxin genes (eta, etb), antibiotic susceptibility and phage typed. Chromosomal DNA was genotyped by MLVF method and PCR/RFLP of coagulase gene were tested. Affected neonates were infected by two clusters of eta-positive S. aureus of phage type 3C/71: (1) MLVF type A isolates resistant only to penicillin, and (2) MLVF type B isolates resistant to penicillin and erythromycin/clindamycin. All isolates were susceptible to methicillin. We found 19 of 67 HCWs to be S. aureus nasal carriers. Two nasal isolates from HCWs were related to the outbreak on the basis of phage typing, PCR detection of eta/etb genes, antibiotyping and genotyping. Additionally, environmental swabs from the maternity unit revealed a 3C/71 S. aureus in the mattress of a baby bed. This is the first documented case of an outbreak of BI caused by phage type 3C/71 eta-positive strain of S. aureus.

  15. PREVALENCE OF BOVINE HERPESVIRUS-1,PARAINFLUENZA-3,BOVINE ROTAVIRUS, BOVINE VIRAL DIARRHEA, BOVINE ADENOVIRUS-7,BOVINE LEUKEMIA VIRUS AND BLUETONGUE VIRUS ANTIBODIES IN CATTLE IN MEXICO

    OpenAIRE

    SUZAN, Victor M.; ONUMA, Misao; AGUILAR, Romero E.; MURAKAMI, Yosuke

    1983-01-01

    Sera were collected from dairy and beef cattle in 19 different states of Mexico. These sera were tested for bovine herpesvirus-1 (BHV-1), parainfluenza-3 virus (PIV-3), bovine rotavirus (BRV), bovine leukemia virus (BLV), bovine adenovirus-7 (BAV-7), bluetongue virus (BTV) and bovine viral diarrhea virus (BVDV). Seropositive rates for each virus for dairy cattle tested were 158/277(57.0%) for BHV-1,217/286(75.0%) for PIV-3,541/1498(36.1%) for BLV, 134/144(93.1%) for BRV, 39/90(43.3%) for BTV,...

  16. Protective effects of tenuigenin on Staphylococcus aureus-induced pneumonia in mice.

    Science.gov (United States)

    Yu, Bin; Qiao, Jiutao; Shen, Yongbin; Li, Lianyong

    2017-09-01

    Pneumonia is the leading cause of death in infants and young children. Staphylococcus aureus (S.aureus) is one of the most important bacteria that leads to pneumonia. Tenuigenin (TGN), a major active component isolated from the root of the Chinese herb Polygala tenuifolia, has been known to have anti-inflammatory effect. In this study, we aimed to investigate the protective effects of TGN on S.aureus-induced pneumonia in mice. The results showed that TGN significantly attenuated S.aureus-induced lung histopathological changes. TGN also inhibited lung wet/dry (W/D) ratio, and inflammatory cytokines TNF-α and IL-1β production. Furthermore, S.aureus-induced NF-κB activation was significantly inhibited by the treatment of TGN. In conclusion, the results of this study showed that TGN protected against S.aureus-induced pneumonia by inhibiting NF-κB activation. TGN might be a potential agent in the treatment of pneumonia induced by S.aureus. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Bovine coronavirus antibody titers at weaning negatively correlate with incidence of bovine respiratory disease in the feed yard

    Science.gov (United States)

    Bovine respiratory disease complex (BRDC) is a multifactorial disease caused by complex interactions among viral and bacterial pathogens, stressful management practices and host genetic variability. Although vaccines and antibiotic treatments are readily available to prevent and treat infection caus...

  18. Sepse por Staphylococus aureus resistente à meticilina adquirida na comunidade no sul do Brasil Sepsis due to community-acquired methicillin-resistant Staphylococcus aureus in southern Brazil

    Directory of Open Access Journals (Sweden)

    Luciane Cristina Gelatti

    2009-08-01

    Full Text Available Staphylococcus aureus resistente à meticilina foi inicialmente descrito como um típico microrganismo adquirido em infecções nosocomiais. No entanto, nos últimos anos Staphylococcus aureus resistente à meticilina adquirido na comunidade é causa de infecções de pele e tecidos moles, mas infecções graves como pneumonia e sepse podem ocorrer. Este relato descreve um caso de sepse em criança, complicado com pneumonia secundária a lesão em partes moles por Staphylococcus aureus resistente à meticilina adquirido na comunidade no Sul do Brasil. O paciente foi atendido em Unidade de Emergência com história de ferimento provocado por trauma em membro inferior que evoluiu para celulite, pneumonia e sepse.Methicillin-resistant Staphylococcus aureus was initially described as a typical microorganism acquired in nosocomial infections. However, over recent years, community-acquired methicillin-resistant Staphylococcus aureus has been a cause of skin and soft-tissue infections. Serious infections such as pneumonia and sepsis can also occur. This report describes a case of sepsis in a child that was complicated by pneumonia secondary to soft tissue lesions that were due to community-acquired methicillin-resistant Staphylococcus aureus in southern Brazil. The patient was attended at the Emergency Unit with a history of injury caused by lower-limb trauma that evolved to cellulitis, pneumonia and sepsis.

  19. Staphylococcus aureus CC398

    DEFF Research Database (Denmark)

    Price, Lance B.; Stegger, Marc; Hasman, Henrik

    2012-01-01

    Since its discovery in the early 2000s, methicillin-resistant Staphylococcus aureus (MRSA) clonal complex 398 (CC398) has become a rapidly emerging cause of human infections, most often associated with livestock exposure. We applied whole-genome sequence typing to characterize a diverse collection...... of CC398 isolates (n = 89), including MRSA and methicillin-susceptible S. aureus (MSSA) from animals and humans spanning 19 countries and four continents. We identified 4,238 single nucleotide polymorphisms (SNPs) among the 89 core genomes. Minimal homoplasy (consistency index = 0.9591) was detected...... among parsimony-informative SNPs, allowing for the generation of a highly accurate phylogenetic reconstruction of the CC398 clonal lineage. Phylogenetic analyses revealed that MSSA from humans formed the most ancestral clades. The most derived lineages were composed predominantly of livestock...

  20. Antiinfective therapy with a small molecule inhibitor of Staphylococcus aureus sortase.

    Science.gov (United States)

    Zhang, Jie; Liu, Hongchuan; Zhu, Kongkai; Gong, Shouzhe; Dramsi, Shaynoor; Wang, Ya-Ting; Li, Jiafei; Chen, Feifei; Zhang, Ruihan; Zhou, Lu; Lan, Lefu; Jiang, Hualiang; Schneewind, Olaf; Luo, Cheng; Yang, Cai-Guang

    2014-09-16

    Methicillin-resistant Staphylococcus aureus (MRSA) is the most frequent cause of hospital-acquired infection, which manifests as surgical site infections, bacteremia, and sepsis. Due to drug-resistance, prophylaxis of MRSA infection with antibiotics frequently fails or incites nosocomial diseases such as Clostridium difficile infection. Sortase A is a transpeptidase that anchors surface proteins in the envelope of S. aureus, and sortase mutants are unable to cause bacteremia or sepsis in mice. Here we used virtual screening and optimization of inhibitor structure to identify 3-(4-pyridinyl)-6-(2-sodiumsulfonatephenyl)[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole and related compounds, which block sortase activity in vitro and in vivo. Sortase inhibitors do not affect in vitro staphylococcal growth yet protect mice against lethal S. aureus bacteremia. Thus, sortase inhibitors may be useful as antiinfective therapy to prevent hospital-acquired S. aureus infection in high-risk patients without the side effects of antibiotics.

  1. Cost Comparison of Linezolid Versus Vancomycin for Treatment of Complicated Skin and Skin-Structure Infection Caused by Methicillin-Resistant Staphylococcus aureus in Quebec

    Directory of Open Access Journals (Sweden)

    Martine Pettigrew

    2012-01-01

    Full Text Available BACKGROUND: In Canada, complicated skin and skin-structure infection (cSSSI caused by methicillin-resistant Staphylococcus aureus (MRSA is usually treated with antibiotics in hospital, with a follow-up course at home for stable patients. The cost implications of using intravenous and oral linezolid instead of intravenous vancomycin in Canadian clinical practice have not been examined.

  2. Filaments in curved streamlines: rapid formation of Staphylococcus aureus biofilm streamers

    International Nuclear Information System (INIS)

    Kevin Kim, Minyoung; Drescher, Knut; Shun Pak, On; Stone, Howard A; Bassler, Bonnie L

    2014-01-01

    Biofilms are surface-associated conglomerates of bacteria that are highly resistant to antibiotics. These bacterial communities can cause chronic infections in humans by colonizing, for example, medical implants, heart valves, or lungs. Staphylococcus aureus, a notorious human pathogen, causes some of the most common biofilm-related infections. Despite the clinical importance of S. aureus biofilms, it remains mostly unknown how physical effects, in particular flow, and surface structure influence biofilm dynamics. Here we use model microfluidic systems to investigate how environmental factors, such as surface geometry, surface chemistry, and fluid flow affect biofilm development of S. aureus. We discovered that S. aureus rapidly forms flow-induced, filamentous biofilm streamers, and furthermore if surfaces are coated with human blood plasma, streamers appear within minutes and clog the channels more rapidly than if the channels are uncoated. To understand how biofilm streamer filaments reorient in flows with curved streamlines to bridge the distances between corners, we developed a mathematical model based on resistive force theory of slender filaments. Understanding physical aspects of biofilm formation of S. aureus may lead to new approaches for interrupting biofilm formation of this pathogen. (paper)

  3. Molecular Characterization of Staphylococcus aureus Isolates Transmitted between Patients with Buruli Ulcer

    NARCIS (Netherlands)

    Amissah, Nana Ama; Chlebowicz, Monika A.; Ablordey, Anthony; Sabat, Artur J.; Tetteh, Caitlin S.; Prah, Isaac; van der Werf, Tjip S.; Friedrich, Alex W.; van Dijl, Jan Maarten; Rossen, John W.; Stienstra, Ymkje

    Background Buruli ulcer (BU) is a skin infection caused by Mycobacterium ulcerans. The wounds of most BU patients are colonized with different microorganisms, including Staphylococcus aureus. Methodology This study investigated possible patient-to-patient transmission events of S. aureus during

  4. Prevalence of methicillin-resistant Staphylococcus aureus skin and nasal carriage isolates from bovines and its antibiogram

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    Alok Kumar

    2017-06-01

    Full Text Available Aim: This study was conducted to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA in cattle and buffalo and to study their antibiotic resistance pattern. Materials and Methods: A total of 136 samples (skin and nasal swab from cattle and buffalo were collected. MRSA was identified by conventional bacterial culture techniques which were further confirmed by amplification of S. aureus-specific 16S rRNA by polymerase chain reaction (PCR. The isolates were further analyzed for the presence of mecA gene by PCR. The antimicrobial susceptibility profiling was performed by disc diffusion method. Results: The prevalence of MRSA in the current study was 28.57% and 34.28% in cattle nasal and skin swab, respectively, with an overall prevalence of 31.43% MRSA among cattle. Buffalo nasal and skin sample showed MRSA prevalence of 54.55% and 39.4%, respectively, with 46.9% overall prevalence. PCR could detect mecA gene in 36.4% and 58% MRSA isolates from cattle and buffalo, respectively. Antimicrobial susceptibility test found MRSA resistant to penicillin and oxytetracycline (88% each, cefoxitin (75%, cotrimoxazole (62%, and amoxyclav (50%. 100% sensitivity was observed against ciprofloxacin, amikacin, chloramphenicol, and gentamicin. Three (16.7% MRSA isolates from buffalo were found resistant to vancomycin. Conclusion: Cattle and buffalo were identified as a potential carrier of MRSA in Bihar (India. The isolation of vancomycinresistant S. aureus (VRSA in the current study indicates the emergence of VRSA in animal population which may be transmitted to the human beings working in close contact to the animals.

  5. Diversity and evolution of blaZ from Staphylococcus aureus and coagulase-negative staphylococci

    DEFF Research Database (Denmark)

    Olsen, John E.; Christensen, Henrik; Aarestrup, Frank Møller

    2006-01-01

    and sequences retrieved from public databases were compared. A phylogenetic tree showed that blaZ exists in three evolutionary lines: one group was of plasmid origin, one group was of chromosomal origin and one intermediate group. Sixty-nine sequence types were demonstrated. They translated into 11 BlaZ protein...... types. The major types all contained strains of both human and bovine origin, and more than one Staphylococcus species, demonstrating a shared gene pool. In a comparison of S. aureus and CoNS obtained from five Danish cattle herds, the same type of blaZ was only detected in one case. Conclusions...

  6. MORPHOLOGICAL ALTERATIONS OF STAPHYLOCOCCUS AUREUS CAUSED BY ARYL ALIPHATIC AMINOALCOHOL DERIVATIVE

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    Dronova M.

    2015-05-01

    Full Text Available Increasing of antimicrobial resistance has created a critical need of the novel antimicrobial agents. One of the promising chemical classes for its development are aryl aliphatic aminoalcohols. New compounds of this class were synthesized at the Institute of organic chemistry (Kiev, Ukraine, by Y. Korotkiy. After the screening studies compound KVM-194 was selected as the potent antistaphylococcal agent. The aim of the study was to examine ultrastructural changes in the bacterial cells under the influence of the compound KVM-194. Materials and methods. Staphylococcus aureus ATCC 25923 was used in all experiments. The minimum inhibitory concentration was determined by serial macrodilution method in Mueller-Hinton broth. Bacteria were exposed to the 0,5 MIC and 5 MICs of the KVM- 194 for 1 h and 24 h. Ultrastructure of intact and treated Staphylococcus aureus cells was examined by transmission electron microscopy after contrasting by osmium tetraoxide and lead citrate. Results and Discussion. The compound KVM-194 possesses a distinct antibacterial activity against Staphylococcus aureus, the minimum inhibitory concentration is 1.25 μg/ml. We found that exposure to KVM-194 at a subinhibitory concentration resulted in alterations of the cell morphology even after 1 h of treatment. The roughness of the cell surface and emerging of the intracellular particles of different electron density were observed. Increase of the incubation time to 24 h led to detachment of membrane from cytoplasm, multimembrane structures within cells emergence and formation of nonpolar septum. 1 h exposition to suprainhibitory concentration of KVM-194 resulted in nucleoid fragmentation, septum abnormalities and necrosis of some cells. We found that increasing of the incubation period to 24 h led to exacerbation of alterations: cell wall rupture, leakage of cytoplasm and a large number of lysed cells were registered. Conclusion. Observed alterations, suggest the possible

  7. Colonization and biofilm formation by Staphylococcus aureus on endothelial cell layers under flow

    DEFF Research Database (Denmark)

    Grønnemose, Rasmus Birkholm; Antoinette Asferg, Cecilie; Kolmos, Hans Jørn

    Staphylococcus aureus is a major human pathogen and known for causing vascular infections such as sepsis and infective endocarditis. It has previously been proposed that S. aureus succeed in colonization of the endothelial wall by specific surface attachment likely followed by biofilm formation....... Furthermore, S. aureus is known to invade human cells, which has been proposed to promote persistence through immune and antibiotic evasion. In the current study, we sought to investigate endothelial colonization, invasion, and biofilm formation by S. aureus using a newly developed in vitro flow chamber model....... We show that under physiological shear rates, S. aureus utilizes cellular invasion to enable the following surface colonization and biofilm formation. These observations might help explain the success of S. aureus as a bloodstream pathogen and guide further studies in S. aureus pathogenesis...

  8. Adherence of Moraxella bovis to cell cultures of bovine origin.

    Science.gov (United States)

    Annuar, B O; Wilcox, G E

    1985-09-01

    The adherence of five strains of Moraxella bovis to cell cultures was investigated. M bovis adhered to cultures of bovine corneal epithelial and Madin-Darby bovine kidney cells but not to cell types of non-bovine origin. Both piliated and unpiliated strains adhered but piliated strains adhered to a greater extent than unpiliated strains. Antiserum against pili of one strain inhibited adherence of piliated strains but caused only slight inhibition of adherence to the unpiliated strains. Treatment of bacteria with magnesium chloride caused detachment of pili from the bacterial cell and markedly inhibited adherence of piliated strains but caused only slight inhibition of adherence by the unpiliated strains. The results suggested that adhesion of piliated strains to cell cultures was mediated via pili but that adhesins other than pili may be involved in the attachment of unpiliated strains of M bovis to cells.

  9. Virulence Factors and Antibiotic Susceptibility of Staphylococcus aureus Isolates in Ready-to-Eat Foods: Detection of S. aureus Contamination and a High Prevalence of Virulence Genes

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    Suat Moi Puah

    2016-02-01

    Full Text Available Staphylococcus aureus is one of the leading causes of food poisoning. Its pathogenicity results from the possession of virulence genes that produce different toxins which result in self-limiting to severe illness often requiring hospitalization. In this study of 200 sushi and sashimi samples, S. aureus contamination was confirmed in 26% of the food samples. The S. aureus isolates were further characterized for virulence genes and antibiotic susceptibility. A high incidence of virulence genes was identified in 96.2% of the isolates and 20 different virulence gene profiles were confirmed. DNA amplification showed that 30.8% (16/52 of the S. aureus carried at least one SE gene which causes staphylococcal food poisoning. The most common enterotoxin gene was seg (11.5% and the egc cluster was detected in 5.8% of the isolates. A combination of hla and hld was the most prevalent coexistence virulence genes and accounted for 59.6% of all isolates. Antibiotic resistance studies showed tetracycline resistance to be the most common at 28.8% while multi-drug resistance was found to be low at 3.8%. In conclusion, the high rate of S. aureus in the sampled sushi and sashimi indicates the need for food safety guidelines.

  10. Epidemiology of Streptococcus pneumoniae and Staphylococcus aureus colonization in healthy Venezuelan children

    OpenAIRE

    Quintero, B.; Araque, M.; van der Gaast-de Jongh, C.; Escalona, F.; Correa, M.; Morillo-Puente, S.; Vielma, S.; Hermans, P. W. M.

    2010-01-01

    Streptococcus pneumoniae and Staphylococcus aureus cause significant morbidity and mortality worldwide. We investigated both the colonization and co-colonization characteristics for these pathogens among 250 healthy children from 2 to 5?years of age in Merida, Venezuela, in 2007. The prevalence of S. pneumoniae colonization, S. aureus colonization, and S. pneumoniae?S. aureus co-colonization was 28%, 56%, and 16%, respectively. Pneumococcal serotypes 6B (14%), 19F (12%), 23F (12%), 15 (9%), 6...

  11. A prospective cohort study of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus carriage in neonates: the role of maternal carriage and phenotypic and molecular characteristics

    Science.gov (United States)

    Lin, Jialing; Wu, Chuanan; Yan, Chunrong; Ou, Qianting; Lin, Dongxin; Zhou, Junli; Ye, Xiaohua; Yao, Zhenjiang

    2018-01-01

    Background Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), in mothers can cause serious outcomes in neonates. We aimed to elucidate the associations of S. aureus and MRSA carriage between mothers and neonates. Methods A prospective cohort study was conducted between August and November 2015 in two hospitals in Shenzhen, China. Chinese pregnant women and their neonates who met the inclusion criteria were included in this study; samples and relevant information were collected. We assessed maternal–neonatal associations by using Poisson regression models. Results Overall, 1834 mothers and their neonates were included in this study. The prevalence of isolate carriage among the mothers was as follows: S. aureus (nasal, 25.8%; vaginal, 7.3%; and nasal and vaginal, 3.3%) and MRSA (nasal, 5.7%; vaginal, 1.7%; and nasal and vaginal, 0.5%). The incidences of S. aureus and MRSA carriage among neonates were 3.3% and 0.8%, respectively. Of the 21 maternal–neonatal pairs with S. aureus carriage, 14 were concordant pairs with the same phenotypic and molecular characteristics. After adjustment, the relative risks and 95% confidence intervals (CIs) between the S. aureus carriage of neonates and nasal S. aureus carriage, vaginal S. aureus carriage, and both nasal and vaginal S. aureus carriage of mothers were 2.8 (95% CI, 1.6–4.8), 7.1 (95% CI, 4.1–12.4), and 9.6 (95% CI, 4.2–22.4), respectively. Conclusion S. aureus carriage in mothers increases the risk for neonates. PMID:29731644

  12. Prevalence and characteristics of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus nasal colonization among a community-based diabetes population in Foshan, China.

    Science.gov (United States)

    Lin, Jialing; Xu, Ping; Peng, Yang; Lin, Dongxin; Ou, Qianting; Zhang, Ting; Bai, Chan; Ye, Xiaohua; Zhou, Junli; Yao, Zhenjiang

    2017-05-01

    Evidence suggests that diabetes might cause an increase in colonization of Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) in community settings. We carried out a cross-sectional study to determine the prevalence and influencing factors of S. aureus and MRSA nasal colonization among a community-based diabetes population, and to identify the characteristics of the isolated strains. A total of 956 participants from 11 community settings were included in the study. Of the 529 diabetes participants, 46 were colonized with S. aureus and 22 were colonized with MRSA. Of the 427 non-diabetes participants, 25 were colonized with S. aureus and 12 were colonized with MRSA. Men (odds ratio 0.45, 95% confidence interval 0.20-0.99, P = 0.047) were less likely to have S. aureus nasal colonization, and those with well-controlled blood glucose (odds ratio 2.04, 95% confidence interval 1.01-4.13, P = 0.047) among the diabetes population were more likely to have S. aureus nasal colonization. The proportion of multidrug-resistant S. aureus strains in the diabetes population (52.17%) was higher than that in the non-diabetes population (28.00%; χ 2 = 3.848, P = 0.050). The most common clonal complex type and Staphylococcal chromosome cassette mec type of MRSA in diabetes population was clonal complex 5 (40.91%) and type IV (27.27%), respectively. The proportion of Panton-Valentine leukocidin gene in MRSA strains was 17.65%. There was great sequence type diversity in MRSA strains. The prevalence of MRSA in the community-based diabetes population was moderate, and the high proportions of multidrug-resistant S. aureus strains and diverse molecular characteristics in the diabetes population should be noticed. © 2016 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

  13. Targeting Staphylococcus aureus Toxins: A Potential form of Anti-Virulence Therapy

    Directory of Open Access Journals (Sweden)

    Cin Kong

    2016-03-01

    Full Text Available Staphylococcus aureus is an opportunistic pathogen and the leading cause of a wide range of severe clinical infections. The range of diseases reflects the diversity of virulence factors produced by this pathogen. To establish an infection in the host, S. aureus expresses an inclusive set of virulence factors such as toxins, enzymes, adhesins, and other surface proteins that allow the pathogen to survive under extreme conditions and are essential for the bacteria’s ability to spread through tissues. Expression and secretion of this array of toxins and enzymes are tightly controlled by a number of regulatory systems. S. aureus is also notorious for its ability to resist the arsenal of currently available antibiotics and dissemination of various multidrug-resistant S. aureus clones limits therapeutic options for a S. aureus infection. Recently, the development of anti-virulence therapeutics that neutralize S. aureus toxins or block the pathways that regulate toxin production has shown potential in thwarting the bacteria’s acquisition of antibiotic resistance. In this review, we provide insights into the regulation of S. aureus toxin production and potential anti-virulence strategies that target S. aureus toxins.

  14. Bovine Tuberculosis, A Zoonotic Disease

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    Tarmudji

    2008-12-01

    Full Text Available Bovine tuberculosis is caused by the infection of Mycobacterium tuberculosis var. bovis (M. bovis. This species is one of Mycobacterium tuberculosis complex, can infect wide range of hosts: cattle and other domesticated animals, wild mammals and humans (zoonotic. M. bovis bacterium from infected hosts can be transmitted to other susceptible animals and humans through respiratory excretes and secretion materials. Humans can be infected with M. bovis by ingested M. bovis contaminated animal products, unpasteurised milk from tuberculosis cows or through respiratory route of contaminated aerosol. Bovine tuberculosis at the first stage does not show any clinical sign but as the disease progress in the next stage which may take several months or years, clinical signs may arise, suh as: fluctuative body temperature, anorexia, lost body weight, coughing, oedema of lymph nodes, increased respiratory frequencies. Pathological lesion of bovine tuberculosis is characterised by the formation of granulomas (tubercles, in which bacterial cells have been localised, most in lymph nodes and pulmonum, but can occur in other organs. The granulomas usually arise in small nodules or tubercles appear yellowish either caseus, caseo-calcareus or calcified. In Indonesia, bovine tuberculosis occurred in dairy cattle since 1905 through the imported dairy cows from Holland and Australian. It was unfortunate that until recently, there were not many research and surveilances of bovine tuberculosis conducted in this country, so the distribution of bovine tuberculosis is unknown. Early serological diagnosis can be done on live cattle by means of tuberculin tests under field conditions. Confirmation can be done by isolation and identification of excreted and secreted samples from the slaughter house. Antibiotic treatment and vaccination were uneffective, therefore the effective control of bovine tuberculosis is suggested by tuberculin tests and by slaughtering the selected

  15. Genotypes, Virulence Factors and Antimicrobial Resistance Genes of Staphylococcus aureus Isolated in Bovine Subclinical Mastitis from Eastern China

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    Javed Memon§, Yongchun Yang§, Jam Kashifa, Muhammad Yaqoob, Rehana Buriroa, Jamila Soomroa, Wang Liping and Fan Hongjie*

    2013-11-01

    Full Text Available This study was carried out to determine the genotypes, virulence factors and antimicrobial resistance traits of 34 Staphylococcus aureus isolated from subclinical mastitis in Eastern China. Minimal inhibitory concentration (MIC results showed resistance to erythromycin in all isolates. A high frequency of Methicillin resistant S. aureus (MRSA; 29% was observed and these isolates were also highly resistant to penicillin, oxacillin, oxytetracycline and chloramphenicol than methicillin sensitive S. aureus (MSSA isolates. Thirteen pathogenic factors and seven resistance genes including mecA and blaZ gene were checked through PCR. The spaX gene was found in all isolates, whereas cna, spaIg, nuc, clfA, fnbpB, hlA, hlB and seA were present in 35, 79, 85, 59, 35, 85, 71 and 38% isolates, respectively. Nine isolates carried a group of 8 different virulence genes. Moreover, macrolide resistance genes ermB and ermC were present in all isolates. High resistance rate against methicillin was found but no isolate was positive for mecA gene, whereas blaZ and tetK were detected in 82 and 56% isolates, respectively. Genes; fnbpA, seB, seC, seD, dfrK and tetM were not found in any isolate. The statistical association between phenotypic resistance and virulence genes showed, clfA, fnbpB, hlB and seA, were potentially associated with penicillin G, ciprofloxacin, methicillin, chloramphenicol, trimethoprim and oxytetracycline resistance (P≤0.05. REP-PCR based genotyping showed seven distinct genotypes (A-G prevalent in this region. This study reports the presence of multidrug resistant S. aureus in sub-clinical mastitis which were also highly virulent that could be a major obstacle in the treatment of mastitis in this region of China.

  16. 21 CFR 526.464b - Cloxacillin benzathine for intramammary infusion, sterile.

    Science.gov (United States)

    2010-04-01

    ... for use. Treatment and prophylaxis of bovine mastitis in nonlactating cows due to Streptococcus... drying-off of the cow. (2) Indications for use. Treatment of mastitis caused by Staphylococcus aureus and...

  17. Characterization of virulence and antibiotic profile and agr typing of Staphylococcus aureus from milk of subclinical mastitis bovine in State of Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    B.S. Soares

    Full Text Available ABSTRACT This study aims to detect the main virulence and antimicrobial resistance genes in Stapylococcus aureus from bovine mastitic milk as well as classifying them according to agr typing. A total of 55 strains from six dairy unities in the state of Rio de Janeiro were selected, of these 27.3% presented fbnA and 78,2% for fbnB genes, respectively. None of the strains tested were positive for cap5 gene, 3.6% were positive for cap8 gene. Additionally, 94.5% of strains had hlA gene and 89.1% had hlB gene while 67.3% of the strains had icaA gene and 87.3% had icaD gene. From these results it was possible to establish 12 different virulence profiles. Prevalence of agrII type was detected in 81.8% of the isolates. Concerning antimicrobial resistance evaluation, the studied strains were susceptible to all antibiotics tested except penicillin, 83.6% being resistant strains. None of the strains had mecA gene, however, 40% of the strains had blaZ gene. Associating virulence and resistance data made it possible to obtain 23 different profiles. This great diversity of strains shows wide array of bacterial strategies and the challenge of mastitis prevention in cattle. Despite antimicrobial susceptibility, these strains presented certain genes that allow its persistence in the herd.

  18. Comparative experimental infection of Listeria monocytogenes and Listeria ivanovii in bovine trophoblasts.

    Science.gov (United States)

    Rocha, Cláudia E; Mol, Juliana P S; Garcia, Luize N N; Costa, Luciana F; Santos, Renato L; Paixão, Tatiane A

    2017-01-01

    Listeria monocytogenes is a Gram-positive, facultative intracellular and invasive bacterium that has tropism to the placenta, and causes fetal morbidity and mortality in several mammalian species. While infection with L. monocytogenes and L. ivanovii are known as important causes of abortion and reproductive failure in cattle, the pathogenesis of maternal-fetal listeriosis in this species is poorly known. This study used the bovine chorioallantoic membrane explant model to investigate the kinetics of L. monocytogenes, L. ivanovii, and L. innocua infections in bovine trophoblastic cells for up to 8 h post infection. L. monocytogenes and L. ivanovii were able to invade and multiply in trophoblastic cells without causing cell death or inducing expression of pro-inflammatory genes. Although L. innocua was unable to multiply in bovine trophoblastic cells, it induced transcription of the pro-inflammatory mediator CXCL6. This study demonstrated for the first time the susceptibility of bovine trophoblastic cells to L. monocytogenes and L. ivanovii infection.

  19. Cross-Talk between Staphylococcus aureus and Other Staphylococcal Species via the agr Quorum Sensing System

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    Jaime Canovas

    2016-11-01

    Full Text Available Staphylococci are associated with both humans and animals. While most are non-pathogenic colonizers, Staphylococcus aureus is an opportunistic pathogen capable of causing severe infections. S. aureus virulence is controlled by the agr quorum sensing system responding to secreted auto-inducing peptides (AIPs sensed by AgrC, a two component histidine kinase. agr loci are found also in other staphylococcal species and for Staphylococcus epidermidis, the encoded AIP represses expression of agr regulated virulence genes in S. aureus. In this study we aimed to better understand the interaction between staphylococci and S. aureus, and show that this interaction may eventually lead to the identification of new anti-virulence candidates to target S. aureus infections. Here we show that culture supernatants of 37 out of 52 staphylococcal isolates representing 17 different species inhibit S. aureus agr. The dog pathogen, Staphylococcus schleiferi, expressed the most potent inhibitory activity and was active against all four agr classes found in S. aureus. By employing a S. aureus strain encoding a constitutively active AIP receptor we show that the activity is mediated via agr. Subsequent cloning and heterologous expression of the S. schleiferi AIP in S. aureus demonstrated that this molecule was likely responsible for the inhibitory activity, and further proof was provided when pure synthetic S. schleiferi AIP was able to completely abolish agr induction of an S. aureus reporter strain. To assess impact on S. aureus virulence, we co-inoculated S. aureus and S. schleiferi in vivo in the Galleria mellonella wax moth larva, and found that expression of key S. aureus virulence factors was abrogated. Our data show that the S. aureus agr locus is highly responsive to other staphylococcal species suggesting that agr is an inter-species communication system. Based on these results we speculate that interactions between S. aureus and other colonizing staphylococci

  20. Antibacterial Effect of Copper on Microorganisms Isolated from Bovine Mastitis

    Science.gov (United States)

    Reyes-Jara, Angelica; Cordero, Ninoska; Aguirre, Juan; Troncoso, Miriam; Figueroa, Guillermo

    2016-01-01

    The antimicrobial properties of copper have been recognized for several years; applying these properties to the prevention of diseases such as bovine mastitis is a new area of research. The aim of the present study was to evaluate in vitro the antimicrobial activity of copper on bacteria isolated from subclinical and clinical mastitis milk samples from two regions in Chile. A total of 327 microorganisms were recovered between March and September 2013, with different prevalence by sample origin (25 and 75% from the central and southern regions of Chile, respectively). In the central region, Escherichia coli and coagulase negative Staphylococci (CNS) were the most frequently detected in clinical mastitis cases (33%), while in the southern region S. uberis, S. aureus, and CNS were detected with frequencies of 22, 21, and 18%, respectively. Antibiotic susceptibility studies revealed that 34% of isolates were resistant to one or more antibiotics and the resistance profile was different between bacterial species and origins of isolation of the bacteria. The minimum inhibitory concentration of copper (MIC-Cu) was evaluated in all the isolates; results revealed that a concentration as low as 250 ppm copper was able to inhibit the great majority of microorganisms analyzed (65% of isolates). The remaining isolates showed a MIC-Cu between 375 and 700 ppm copper, and no growth was observed at 1000 ppm. A linear relationship was found between the logarithm of viable bacteria number and time of contact with copper. With the application of the same concentration of copper (250 ppm), CNS showed the highest tolerance to copper, followed by S. uberis and S. aureus; the least resistant was E. coli. Based on these in vitro results, copper preparations could represent a good alternative to dipping solutions, aimed at preventing the presence and multiplication of potentially pathogenic microorganisms involved in bovine mastitis disease. PMID:27199953

  1. Characterization of a mouse-adapted Staphylococcus aureus strain.

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    Silva Holtfreter

    Full Text Available More effective antibiotics and a protective vaccine are desperately needed to combat the 'superbug' Staphylococcus aureus. While in vivo pathogenicity studies routinely involve infection of mice with human S. aureus isolates, recent genetic studies have demonstrated that S. aureus lineages are largely host-specific. The use of such animal-adapted S. aureus strains may therefore be a promising approach for developing more clinically relevant animal infection models. We have isolated a mouse-adapted S. aureus strain (JSNZ which caused a severe outbreak of preputial gland abscesses among male C57BL/6J mice. We aimed to extensively characterize this strain on a genomic level and determine its virulence potential in murine colonization and infection models. JSNZ belongs to the MLST type ST88, rare among human isolates, and lacks an hlb-converting phage encoding human-specific immune evasion factors. Naive mice were found to be more susceptible to nasal and gastrointestinal colonization with JSNZ than with the human-derived Newman strain. Furthermore, naïve mice required antibiotic pre-treatment to become colonized with Newman. In contrast, JSNZ was able to colonize mice in the absence of antibiotic treatment suggesting that this strain can compete with the natural flora for space and nutrients. In a renal abscess model, JSNZ caused more severe disease than Newman with greater weight loss and bacterial burden. In contrast to most other clinical isolates, JSNZ can also be readily genetically modified by phage transduction and electroporation. In conclusion, the mouse-adapted strain JSNZ may represent a valuable tool for studying aspects of mucosal colonization and for screening novel vaccines and therapies directed at preventing colonization.

  2. The effect of temperature and Pasteurization time on Staphylococcus aureus isolates from dairy products

    Science.gov (United States)

    Yaniarti, Maria Nia; Amarantini, Charis; Budiarso, Tri Yahya

    2017-11-01

    Staphylococcus aureus is a potential pathogenic bacterial cause of disease in humans and animals due to the ability of adhesion to epithelial tissue. Many cases of food poisoning are caused by S. aureus bacteria. Therefore, the purpose of this study was to determine the effect of temperature and time on the growth of S. aureus isolates from milk products. The samples are derived from previous research namely pasteurized milk, street vendor and café milk, milk powder, and sweetened condensed milk products. The treatment temperatures and times studied were temperature 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, and 30, 35, 40, 45, 50, 55, and 60 minutes. The results show that at temperatures of 60 °C and 65 °C, S. aureus isolates did not grow at 60 minutes. All isolates of S. aureus died when the temperatures were increased to 70 °C and 80 °C, at 50 and 20 minutes, respectively.

  3. Staphylococcus aureus urinary tract infections in children are associated with urinary tract abnormalities and vesico-ureteral reflux.

    Science.gov (United States)

    Megged, Orli

    2014-02-01

    Staphylococcus aureus is an uncommon cause of pediatric urinary tract infection (UTI). Data regarding urinary tract malformations in children with S. aureus UTI is limited. The medical records of all children aged 0 to 16 years at Shaare Zedek Medical Center between 2001 and 2013 and who were diagnosed with S. aureus UTI were reviewed for demographic, clinical, and laboratory data. Patients with Escherichia coli UTIs during the same period were included as controls. S. aureus was the cause of UTI in 26 children, of whom six were bacteremic. Compared to children with E. coli UTI, children with S. aureus had higher rates of abnormal findings in ultrasound (77 vs. 22%; p UTI had abnormal voiding cystourethrogram (53 vs. 23%; p UTI was significantly longer than for patients with E. coli UTI (8 vs. 2.3 days; p = 0.0003). S. aureus is an uncommon urinary pathogen among children. The finding of S. aureus UTI requires thorough search for urinary abnormalities.

  4. Epithelial Cell Gene Expression Induced by Intracellular Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Xianglu Li

    2009-01-01

    Full Text Available HEp-2 cell monolayers were cocultured with intracellular Staphylococcus aureus, and changes in gene expression were profiled using DNA microarrays. Intracellular S. aureus affected genes involved in cellular stress responses, signal transduction, inflammation, apoptosis, fibrosis, and cholesterol biosynthesis. Transcription of stress response and signal transduction-related genes including atf3, sgk, map2k1, map2k3, arhb, and arhe was increased. In addition, elevated transcription of proinflammatory genes was observed for tnfa, il1b, il6, il8, cxcl1, ccl20, cox2, and pai1. Genes involved in proapoptosis and fibrosis were also affected at transcriptional level by intracellular S. aureus. Notably, intracellular S. aureus induced strong transcriptional down-regulation of several cholesterol biosynthesis genes. These results suggest that epithelial cells respond to intracellular S. aureus by inducing genes affecting immunity and in repairing damage caused by the organism, and are consistent with the possibility that the organism exploits an intracellular environment to subvert host immunity and promote colonization.

  5. Bovine Virus Diarrhea (BVD)

    OpenAIRE

    Hoar, Bruce R.

    2004-01-01

    Bovine virus diarrhea (BVD) is a complicated disease to discuss as it can result in a wide variety of disease problems from very mild to very severe. BVD can be one of the most devastating diseases cattle encounter and one of the hardest to get rid of when it attacks a herd. The viruses that cause BVD have been grouped into two genotypes, Type I and Type II. The disease syndrome caused by the two genotypes is basically the same, however disease caused by Type II infection is often more severe...

  6. PCR-based Approaches for the Detection of Clinical Methicillin-resistant Staphylococcus aureus

    Science.gov (United States)

    Liu, Ying; Zhang, Jiang; Ji, Yinduo

    2016-01-01

    Staphylococcus aureus is an important pathogen that can cause a variety of infections, including superficial and systematic infections, in humans and animals. The persistent emergence of multidrug resistant S. aureus, particularly methicillin-resistant S. aureus, has caused dramatically economic burden and concerns in the public health due to limited options of treatment of MRSA infections. In order to make a correct choice of treatment for physicians and understand the prevalence of MRSA, it is extremely critical to precisely and timely diagnose the pathogen that induces a specific infection of patients and to reveal the antibiotic resistant profile of the pathogen. In this review, we outlined different PCR-based approaches that have been successfully utilized for the rapid detection of S. aureus, including MRSA and MSSA, directly from various clinical specimens. The sensitivity and specificity of detections were pointed out. Both advantages and disadvantages of listed approaches were discussed. Importantly, an alternative approach is necessary to further confirm the detection results from the molecular diagnostic assays. PMID:27335617

  7. Clinically mild encephalitis/encephalopathy with a reversible splenial lesion caused by methicillin-sensitive Staphylococcus aureus bacteremia with toxic shock syndrome: a case report.

    Science.gov (United States)

    Kosami, Koki; Kenzaka, Tsuneaki; Sagara, Yuka; Minami, Kensuke; Matsumura, Masami

    2016-04-18

    Clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) is a mild encephalopathy caused by various pathological processes, but encephalopathy due to bacteria is rare. We report the case of a 45-year-old Japanese woman who on receiving chemotherapy for advanced breast cancer developed an altered mental status and dysarthria soon after fever from infection of a subcutaneous implantable port. Staphylococcus aureus was detected in her blood cultures. Magnetic resonance imaging (MRI) revealed an ovoid lesion in the central portion of the splenium of the corpus callosum (SCC). Although hypotension was not observed, we diagnosed probable toxic shock syndrome (TSS) based on fever (temperature: >38.9 °C), altered mental status, erythema, desquamation, thrombocytopenia, liver dysfunction, and creatine phosphokinase elevation. We administered antimicrobial therapy and her neurological symptoms improved gradually. The lesion in the SCC completely disappeared on MRI 7 days after disease onset. We diagnosed this case as MERS caused by S. aureus bacteremia with TSS. This is the first report of such a case, and we suggest that when a TSS patient presents with neurological symptoms, the possibility of MERS should be considered.

  8. Screening of virulence genes in Staphylococcus aureus isolates from rabbits

    Directory of Open Access Journals (Sweden)

    David Viana Martín

    2015-09-01

    Full Text Available Staphylococcus aureus is a versatile pathogen able to cause disease in both humans and animals. In rabbits, this bacterium infects animals of different ages, producing several purulent lesions. The ability of S. aureus to cause disease depends on a combination of virulence factors. The aim of this study was therefore to investigate the distribution of bacterial virulence determinants in 69 S. aureus isolates from rabbits. Some virulence factors (7 adhesins, 1 toxin and 1 protease were positive in all rabbit S. aureus isolates analysed, while others (1 adhesin and 10 toxins were always negative. The remaining virulence factors were more variable among isolates. An association between genotype and the different profiles of virulence factors was observed, but not with the type of lesion (P<0.05. One strain of each genotype was further analysed by multilocus sequence typing, generating ST121, ST96 and ST2951, determining a greater number of enterotoxins in ST121 isolates compared to ST96 and ST2951 isolates, which could justify the different pathogenicity between strains. 

  9. Staphylococcus aureus and community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in and around therapeutic whirlpools in college athletic training rooms.

    Science.gov (United States)

    Kahanov, Leamor; Kim, Young Kyun; Eberman, Lindsey; Dannelly, Kathleen; Kaur, Haninder; Ramalinga, A

    2015-04-01

    Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a leading cause of skin and soft tissue infection in the nonhospitalized community. Care of the athletes in athletic training rooms is specifically designed with equipment tailored to the health care needs of the athletes, yet recent studies indicate that CA-MRSA is still prevalent in athletic facilities and that cleaning methods may not be optimal. To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Cross-sectional study. National Collegiate Athletic Association Division I university. Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. We identified Staphylococcus aureus in 22% (n = 52/240) of the samples and MRSA in 0.8% (n = 2/240). A statistically significant difference existed between the number of athletes using the whirlpool and the presence of Staphylococcus aureus in and around the whirlpools (F(2,238) = 2.445, P = .007). However, Staphylococcus aureus was identified regardless of whether multiple athletes used a whirlpool or no athletes used a whirlpool. We did not identify a relationship between the number of athletes who used a whirlpool and Staphylococcus aureus or MRSA density (P = .134). Staphylococcus aureus and MRSA were identified in and around the whirlpools. Transmission of the bacteria can be reduced by following the cleaning and disinfecting protocols recommended by the Centers for Disease Control and Prevention. Athletic trainers should use disinfectants registered by the Environmental Protection Agency to sanitize all whirlpools between uses.

  10. Activation of bovine neutrophils by Brucella spp.

    Science.gov (United States)

    Keleher, Lauren L; Skyberg, Jerod A

    2016-09-01

    Brucellosis is a globally important zoonotic infectious disease caused by gram negative bacteria of the genus Brucella. While many species of Brucella exist, Brucella melitensis, Brucella abortus, and Brucella suis are the most common pathogens of humans and livestock. The virulence of Brucella is largely influenced by its ability to evade host factors, including phagocytic killing mechanisms, which are critical for the host response to infection. The aim of this study was to characterize the bovine neutrophil response to virulent Brucella spp. Here, we found that virulent strains of smooth B. abortus, B. melitensis, B. suis, and virulent, rough, strains of Brucella canis possess similar abilities to resist killing by resting, or IFN-γ-activated, bovine neutrophils. Bovine neutrophils responded to infection with a time-dependent oxidative burst that varied little between Brucella spp. Inhibition of TAK1, or SYK kinase blunted the oxidative burst of neutrophils in response to Brucella infection. Interestingly, Brucella spp. did not induce robust death of bovine neutrophils. These results indicate that bovine neutrophils respond similarly to virulent Brucella spp. In addition, virulent Brucella spp., including naturally rough strains of B. canis, have a conserved ability to resist killing by bovine neutrophils. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Characterization of the Fermentation Process and the Inhibition Effect of Lactobacillus lactis in Staphylococcus aureus and Staphylococcus epidermidis

    Directory of Open Access Journals (Sweden)

    Henry Jurado-Gámez

    2015-09-01

    Full Text Available The fermentative process and in vitro inhibition of L. lactis in Staphylococcus aureus and Staphylococcus epidermidis were assessed. The growth of L. lactis at three pH (2.5, 4.5 and 7, bile salts (0.5, 1 and 2 %, bovine bile (1 and 1.2 % and two temperatures (38 and 45 °C were evaluated. Peptides and organic acids in supernatant of L. lactis by HPLC were determined. Fermentation kinetics was carried out, evaluating: pH, total sugar, protein and lactic acid. An antibiogram of dicloxacilin, cefepime, penilicin and cefalotin was made. The inhibition of L. lactis and its supernatant were defined in pathogenic strains. The best growth was at a pH of 2.5 (3 × 1012 UFC/ml; of 1 × 1010 and 4 × 109 UFC/ml for 0.5 % of bile salts and 1.2 % of bovine bile, respectively; of 3.5 × 1013 and 3.4 × 1013 UFC/ml for 38 and 45 °C, respectively. The HPLC determined the peptides VAR-TIR-VAR and lactic acid (83.11 %. The fermentation kinetics determined the exponential phase at 14:24 h with a value of 77 × 1010 UFC/ ml, pH values of 4.284, 2.33 mg/ml sugar, 1.44 mg/ml protein and acidity of 0.79 %. It was found that S. aureus and S. epidermidis were sensitive to all antibiotics. The pathogenic bacteria were resistant to the lactic strain, but S. epidermidis was sensitive to the supernatant of L. lactis. The conclusion is that Lactobacillus lactis showed adequate growth capacity, good fermentation parameters and inhibitory effect in strains of S. aureus and S. epidermidis in in vitro conditions.

  12. Molecular Characterization of Staphylococcus aureus Isolates Transmitted between Patients with Buruli Ulcer.

    Science.gov (United States)

    Amissah, Nana Ama; Chlebowicz, Monika A; Ablordey, Anthony; Sabat, Artur J; Tetteh, Caitlin S; Prah, Isaac; van der Werf, Tjip S; Friedrich, Alex W; van Dijl, Jan Maarten; Rossen, John W; Stienstra, Ymkje

    2015-01-01

    Buruli ulcer (BU) is a skin infection caused by Mycobacterium ulcerans. The wounds of most BU patients are colonized with different microorganisms, including Staphylococcus aureus. This study investigated possible patient-to-patient transmission events of S. aureus during wound care in a health care center. S. aureus isolates from different BU patients with overlapping visits to the clinic were whole-genome sequenced and analyzed by a gene-by-gene approach using SeqSphere(+) software. In addition, sequence data were screened for the presence of genes that conferred antibiotic resistance. SeqSphere(+) analysis of whole-genome sequence data confirmed transmission of methicillin resistant S. aureus (MRSA) and methicillin susceptible S. aureus among patients that took place during wound care. Interestingly, our sequence data show that the investigated MRSA isolates carry a novel allele of the fexB gene conferring chloramphenicol resistance, which had thus far not been observed in S. aureus.

  13. Left-sided native valve Staphylococcus aureus endocarditis

    NARCIS (Netherlands)

    Slabbekoorn, M.; Horlings, H. M.; van der Meer, J. T. M.; Windhausen, A.; Van der Sloot, J. A. P.; Lagrand, W. K.

    2010-01-01

    Despite improved diagnostic tools and expanded treatment options, left-sided native valve endocarditis caused by Staphylococcus aureus infection remains a serious and destructive disease. The high morbidity and mortality, however, can be reduced by early recognition, correct diagnosis, and

  14. Parachlamydia spp. and Related Chlamydia-like Organisms and Bovine Abortion

    Science.gov (United States)

    Borel, Nicole; Ruhl, Silke; Casson, Nicola; Kaiser, Carmen; Pospischil, Andreas

    2007-01-01

    Chlamydophila abortus and Waddlia chondrophila cause abortion in ruminants. We investigated the role of Parachlamydia acanthamoebae in bovine abortion. Results of immunohistochemical analyses were positive in 30 (70%) of 43 placentas from which Chlamydia-like DNA was amplified, which supports the role of Parachlamydia spp. in bovine abortion. PMID:18258043

  15. Passive therapy with humanized anti-staphylococcal enterotoxin B antibodies attenuates systemic inflammatory response and protects from lethal pneumonia caused by staphylococcal enterotoxin B-producing Staphylococcus aureus.

    Science.gov (United States)

    Karau, Melissa J; Tilahun, Mulualem E; Krogman, Ashton; Osborne, Barbara A; Goldsby, Richard A; David, Chella S; Mandrekar, Jayawant N; Patel, Robin; Rajagopalan, Govindarajan

    2017-10-03

    Drugs such as linezolid that inhibit bacterial protein synthesis may be beneficial in treating infections caused by toxigenic Staphylococcus aureus. As protein synthesis inhibitors have no effect on preformed toxins, neutralization of pathogenic exotoxins with anti-toxin antibodies may be beneficial in conjunction with antibacterial therapy. Herein, we evaluated the efficacy of human-mouse chimeric high-affinity neutralizing anti-staphylococcal enterotoxin B (SEB) antibodies in the treatment of experimental pneumonia caused by SEB-producing S. aureus. Since HLA class II transgenic mice mount a stronger systemic immune response following challenge with SEB and are more susceptible to SEB-induced lethal toxic shock than conventional mice strains, HLA-DR3 transgenic mice were used. Lethal pneumonia caused by SEB-producing S. aureus in HLA-DR3 transgenic mice was characterized by robust T cell activation and elevated systemic levels of several pro-inflammatory cytokines and chemokines. Prophylactic administration of a single dose of linezolid 30 min prior to the onset of infection attenuated the systemic inflammatory response and protected from mortality whereas linezolid administered 60 min after the onset of infection failed to confer significant protection. Human-mouse chimeric high-affinity neutralizing anti-SEB antibodies alone, but not polyclonal human IgG, mitigated this response and protected from death when administered immediately after initiation of infection. Further, anti-SEB antibodies as well as intact polyclonal human IgG, but not its Fab or Fc fragments, protected from lethal pneumonia when followed with linezolid therapy 60 min later. In conclusion, neutralization of superantigens with high-affinity antibodies may have beneficial effects in pneumonia.

  16. Pulsed-field gel electrophoresis (PFGE): application in population structure studies of bovine mastitis-causing streptococci.

    Science.gov (United States)

    Santos-Sanches, Ilda; Chambel, Lélia; Tenreiro, Rogério

    2015-01-01

    Pulsed-field gel electrophoresis (PFGE) separates large DNA molecules by the use of an alternating electrical field, such that greater size resolution can be obtained when compared to normal agarose gel electrophoresis. PFGE is often employed to track pathogens and is a valuable typing scheme to detect and differentiate strains. Particularly, the contour-clamped homogeneous electric field (CHEF) PFGE system is considered to be the gold standard for use in epidemiological studies of many bacterial pathogens. Here we describe a PFGE protocol that was applicable to the study of bovine streptococci, namely, Streptococcus agalactiae (group B Streptococcus, GBS), Streptococcus dysgalactiae subsp. dysgalactiae (group C Streptococcus, GCS), and Streptococcus uberis-which are relevant pathogens causing mastitis, a highly prevalent and costly disease in dairy industry due to antibiotherapy and loss in milk production.

  17. Genomic investigation of Danish Staphylococcus aureus isolates from bulk tank milk and dairy cows with clinical mastitis

    DEFF Research Database (Denmark)

    Ronco, Troels; Klaas, Ilka C.; Stegger, Marc

    2018-01-01

    Staphylococcus aureus is one of the most common pathogens that cause mastitis in dairy cows. Various subtypes, virulence genes and pathogenicity islands have been associated with isolates from bulk tank milk and clinical mastitis. So far, no Danish cattle associated S. aureus isolates have been...... and clinical mastitis were of similar genetic background. This suggests that dairy cows are natural carriers of the S. aureus subtypes that cause clinical mastitis if the right conditions are present and that a broad range of subtypes cause mastitis. A phylogenetic cluster that mostly consisted of ST151...... isolates carried three pathogenicity islands that were primarily found in this group. The prevalence of resistance genes was generally low. However, the first ST398 methicillin resistant S. aureus isolate from a Danish dairy cow with clinical mastitis was detected....

  18. Molecular and mathematical epidemiology of Staphylococcus aureus and Streptococcus uberis mastitis in dairy herds

    NARCIS (Netherlands)

    Zadoks, Ruth Nicolet

    2002-01-01

    Mastitis is the most common and costly production disease affecting dairy cows. Staphylococcus aureus and Streptococcus uberis are two major mastitis-causing pathogens. Staphylococcus aureus is traditionally classified as contagious pathogen, while Streptococcus uberis is classified as environmental

  19. Staphylococcal species associated with bovine mastitis in the North West of Iran: Emerging of coagulase-negative staphylococci

    Directory of Open Access Journals (Sweden)

    Somayyeh Hosseinzadeh

    2014-06-01

    Full Text Available Staphylococcal mastitis is a major and costly problem of dairy cattle all over the world. The objective of this study was to isolate and identify the main staphylococcal species causing bovine mastitis in 7 dairy herds located in 4 different areas of East and West Azerbaijan provinces, Iran. Of the 158 mastitic milk samples collected, 113 staphylococcal isolates were identified (71.5% on the basis of cultural and biochemical features as well as by genus specific PCR. Then, species level identification of staphylococcal isolates was carried out using restriction fragment length polymorphism (RFLP analysis of the gap gene (933 bp. On the basis of polymerase chain reaction-RFLP, 10 different patterns were identified. Of 113 isolates, 5 (4.4% were Staphylococcus aureus and 108 (95.6% were coagulase-negative staphylococci (CoNS. Overall, nine different species of CoNS were identified as: 44 Staphylococcus haemolyticus (40.7%, 17 Staphylococcus chromogenes (15.7%, 11 Staphylococcus epidermidis, Staphylococcus warneri and Staphylococcus cohnii each (10.2%, 6 Staphylococcus simulans (5.5%, 4 Staphylococcus hominis (3.7%, 3 Staphylococcus capitis (2.7% and 1 Staphylococcus xylosus (0.9%. S. haemolyticus, S. chromogenes and S. warneri were the only species identified from clinical mastitis. No significant difference in staphylococcal IMI was found among the studied herds and regions. This study demonstrated that CoNS, especially S. haemolyticus and S. chromogenes, were predominant and thus be considered as emerging pathogens causing mastitis in the North West of Iran. Our results also revealed that the gap PCR-RFLP was useful for identifying staphylococcal isolates derived from bovine mastitis at species level.

  20. Staphylococcus aureus and Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA) in and Around Therapeutic Whirlpools in College Athletic Training Rooms

    Science.gov (United States)

    Kahanov, Leamor; Kim, Young Kyun; Eberman, Lindsey; Dannelly, Kathleen; Kaur, Haninder; Ramalinga, A.

    2015-01-01

    Context: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a leading cause of skin and soft tissue infection in the nonhospitalized community. Care of the athletes in athletic training rooms is specifically designed with equipment tailored to the health care needs of the athletes, yet recent studies indicate that CA-MRSA is still prevalent in athletic facilities and that cleaning methods may not be optimal. Objective: To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Design: Cross-sectional study. Setting: National Collegiate Athletic Association Division I university. Patients or Other Participants: Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Main Outcome Measure(s): Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. Results: We identified Staphylococcus aureus in 22% (n = 52/240) of the samples and MRSA in 0.8% (n = 2/240). A statistically significant difference existed between the number of athletes using the whirlpool and the presence of Staphylococcus aureus in and around the whirlpools (F2,238 = 2.445, P = .007). However, Staphylococcus aureus was identified regardless of whether multiple athletes used a whirlpool or no athletes used a whirlpool. We did not identify a relationship between the number of athletes who used a whirlpool and Staphylococcus aureus or MRSA density (P = .134). Conclusions: Staphylococcus aureus and MRSA were identified in and around the whirlpools. Transmission of the bacteria can be reduced by following the cleaning and disinfecting protocols recommended by the Centers for Disease Control and Prevention. Athletic trainers should use disinfectants registered by the Environmental Protection Agency to sanitize all whirlpools between uses. PMID:25710853

  1. The vaccines for Bovine Herpesvirus Type 1: A review | Zhao ...

    African Journals Online (AJOL)

    Bovine herpesvirus type 1 (BoHV-1) is the pathogen of Infectious Bovine Rhinothracheitis (IBR) disease, causing great economic losses in the livestock industry. Vaccine is a powerful means to control the virus. Here, the review described the currently available knowledge regarding to the advance in the field of BoHV-1 ...

  2. Sequence diversities of serine-aspartate repeat genes among Staphylococcus aureus isolates from different hosts presumably by horizontal gene transfer.

    Directory of Open Access Journals (Sweden)

    Huping Xue

    Full Text Available BACKGROUND: Horizontal gene transfer (HGT is recognized as one of the major forces for bacterial genome evolution. Many clinically important bacteria may acquire virulence factors and antibiotic resistance through HGT. The comparative genomic analysis has become an important tool for identifying HGT in emerging pathogens. In this study, the Serine-Aspartate Repeat (Sdr family has been compared among different sources of Staphylococcus aureus (S. aureus to discover sequence diversities within their genomes. METHODOLOGY/PRINCIPAL FINDINGS: Four sdr genes were analyzed for 21 different S. aureus strains and 218 mastitis-associated S. aureus isolates from Canada. Comparative genomic analyses revealed that S. aureus strains from bovine mastitis (RF122 and mastitis isolates in this study, ovine mastitis (ED133, pig (ST398, chicken (ED98, and human methicillin-resistant S. aureus (MRSA (TCH130, MRSA252, Mu3, Mu50, N315, 04-02981, JH1 and JH9 were highly associated with one another, presumably due to HGT. In addition, several types of insertion and deletion were found in sdr genes of many isolates. A new insertion sequence was found in mastitis isolates, which was presumably responsible for the HGT of sdrC gene among different strains. Moreover, the sdr genes could be used to type S. aureus. Regional difference of sdr genes distribution was also indicated among the tested S. aureus isolates. Finally, certain associations were found between sdr genes and subclinical or clinical mastitis isolates. CONCLUSIONS: Certain sdr gene sequences were shared in S. aureus strains and isolates from different species presumably due to HGT. Our results also suggest that the distributional assay of virulence factors should detect the full sequences or full functional regions of these factors. The traditional assay using short conserved regions may not be accurate or credible. These findings have important implications with regard to animal husbandry practices that may

  3. Staphylococcus aureus from 152 cases of bovine, ovine and caprine mastitis investigated by Multiple-locus variable number of tandem repeat analysis (MLVA).

    Science.gov (United States)

    Bergonier, Dominique; Sobral, Daniel; Feßler, Andrea T; Jacquet, Eric; Gilbert, Florence B; Schwarz, Stefan; Treilles, Michaël; Bouloc, Philippe; Pourcel, Christine; Vergnaud, Gilles

    2014-10-02

    Staphylococcus aureus is one of the main etiological agents of mastitis in ruminants. In the present retrospective study, we evaluated the potential interest of a previously described automated multiple loci Variable Number of Tandem Repeats (VNTR) Assay (MLVA) comprising 16 loci as a first line tool to investigate the population structure of S. aureus from mastitis. We determined the genetic diversity of S. aureus strains from cases of clinical and subclinical mastitis in dairy cattle (n = 118, of which 16 were methicillin-resistant), sheep (n = 18) and goats (n = 16). The 152 strains could be subdivided into 115 MLVA genotypes (including 14 genotypes for the ovine strains and 15 genotypes for the caprine strains). This corresponds to a discriminatory index (D) value of 0.9936. Comparison with published MLVA data obtained using the same protocol applied to strains from diverse human and animal origins revealed a low number (8.5%) of human-related MLVA genotypes among the present collection. Eighteen percent of the S. aureus mastitis collection belonged to clonal complexes apparently not associated with other pathological conditions. Some of them displayed a relatively low level of diversity in agreement with a restricted ecological niche. These findings provide arguments suggesting that specific S. aureus lineages particularly adapted to ruminant mammary glands have emerged and that MLVA is a convenient tool to provide a broad overview of the population, owing to the availability via internet of databases compiling published MLVA genotypes.

  4. Molecular Characterization of Staphylococcus aureus Isolates Transmitted between Patients with Buruli Ulcer.

    Directory of Open Access Journals (Sweden)

    Nana Ama Amissah

    Full Text Available Buruli ulcer (BU is a skin infection caused by Mycobacterium ulcerans. The wounds of most BU patients are colonized with different microorganisms, including Staphylococcus aureus.This study investigated possible patient-to-patient transmission events of S. aureus during wound care in a health care center. S. aureus isolates from different BU patients with overlapping visits to the clinic were whole-genome sequenced and analyzed by a gene-by-gene approach using SeqSphere(+ software. In addition, sequence data were screened for the presence of genes that conferred antibiotic resistance.SeqSphere(+ analysis of whole-genome sequence data confirmed transmission of methicillin resistant S. aureus (MRSA and methicillin susceptible S. aureus among patients that took place during wound care. Interestingly, our sequence data show that the investigated MRSA isolates carry a novel allele of the fexB gene conferring chloramphenicol resistance, which had thus far not been observed in S. aureus.

  5. The bactericidal mechanism of action against Staphylococcus aureus for AgO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Wenning, E-mail: shenwenning@qq.com [School of Materials Science and Engineering, Xi' an University of Technology, No. 5 South Jinhua Road, Xi' an 710048 (China); Li, Pin [School of Materials Science and Engineering, Xi' an University of Technology, No. 5 South Jinhua Road, Xi' an 710048 (China); Feng, Hui [Shaanxi Institute of Zoology, Xi' an 710032 (China); Ge, Yanfeng; Liu, Zheng; Feng, Lajun [School of Materials Science and Engineering, Xi' an University of Technology, No. 5 South Jinhua Road, Xi' an 710048 (China)

    2017-06-01

    To identify the mechanistic effects of AgO nanoparticles on Gram-positive bacteria, S. aureus cells suspended in phosphate buffer solution (PBS) and deionized water were separately treated using AgO nanoparticles at different concentrations. The phase composition changes of the bactericide after killing S. aureus and the cellular responses of S. aureus to AgO were characterized by X-ray diffraction, atomic absorption spectrophotometer, scanning electron microscopy, transmission electron microscopy, and energy dispersive spectroscopy. The results show that AgO nanoparticles could kill S. aureus suspended in PBS and deionized water. The bactericidal effect of AgO bactericide against S. aureus in water was better than that in PBS, due to the formation of Ag{sub 3}PO{sub 4} from the reaction between AgO and PBS. AgO nanoparticles exerted their bactericidal activity by multiple processes. AgO nanoparticles adhered to the surface of S. aureus cells firstly, then induced physical alterations in cell morphology and released silver ions, leading to initial injuries of cell membrane. Once membrane damage occurred, they entered the cells, and damaged the intracellular materials, eventually causing severe morphological and structural injuries to the cells and leakage of cytoplasm. - Highlights: • S. aureus in water was more sensitive to AgO than in PBS, since AgO reacted with PBS and formed Ag{sub 3}PO{sub 4}. • After killing S. aureus in water, AgO did not changed. • AgO particles attached to cell surface then interacted with the cells, resulting in the increase of released silver contents. • Cell membrane damages by AgO nanoparticles were supported by the leakages of K{sup +}, proteins and DNA. • Serious cell morphological and structural changes were caused by AgO nanoparticles.

  6. The bactericidal mechanism of action against Staphylococcus aureus for AgO nanoparticles

    International Nuclear Information System (INIS)

    Shen, Wenning; Li, Pin; Feng, Hui; Ge, Yanfeng; Liu, Zheng; Feng, Lajun

    2017-01-01

    To identify the mechanistic effects of AgO nanoparticles on Gram-positive bacteria, S. aureus cells suspended in phosphate buffer solution (PBS) and deionized water were separately treated using AgO nanoparticles at different concentrations. The phase composition changes of the bactericide after killing S. aureus and the cellular responses of S. aureus to AgO were characterized by X-ray diffraction, atomic absorption spectrophotometer, scanning electron microscopy, transmission electron microscopy, and energy dispersive spectroscopy. The results show that AgO nanoparticles could kill S. aureus suspended in PBS and deionized water. The bactericidal effect of AgO bactericide against S. aureus in water was better than that in PBS, due to the formation of Ag 3 PO 4 from the reaction between AgO and PBS. AgO nanoparticles exerted their bactericidal activity by multiple processes. AgO nanoparticles adhered to the surface of S. aureus cells firstly, then induced physical alterations in cell morphology and released silver ions, leading to initial injuries of cell membrane. Once membrane damage occurred, they entered the cells, and damaged the intracellular materials, eventually causing severe morphological and structural injuries to the cells and leakage of cytoplasm. - Highlights: • S. aureus in water was more sensitive to AgO than in PBS, since AgO reacted with PBS and formed Ag 3 PO 4 . • After killing S. aureus in water, AgO did not changed. • AgO particles attached to cell surface then interacted with the cells, resulting in the increase of released silver contents. • Cell membrane damages by AgO nanoparticles were supported by the leakages of K + , proteins and DNA. • Serious cell morphological and structural changes were caused by AgO nanoparticles.

  7. Evaluation of approaches to monitor Staphylococcus aureus virulence factor expression during human disease

    NARCIS (Netherlands)

    Rozemeijer, Wouter; Fink, Pamela; Rojas, Eduardo; Jones, C Hal; Pavliakova, Danka; Giardina, Peter; Murphy, Ellen; Liberator, Paul; Jiang, Qin; Girgenti, Douglas; Peters, Remco P H; Savelkoul, Paul H M; Jansen, Kathrin U; Anderson, Annaliesa S; Kluytmans, Jan

    2015-01-01

    Staphylococcus aureus is a versatile pathogen of medical significance, using multiple virulence factors to cause disease. A prophylactic S. aureus 4-antigen (SA4Ag) vaccine comprising capsular polysaccharide (types 5 and 8) conjugates, clumping factor A (ClfA) and manganese transporter C (MntC) is

  8. The clinical and molecular epidemiology of Staphylococcus aureus infections in Fiji.

    Science.gov (United States)

    Jenney, Adam; Holt, Deborah; Ritika, Roselyn; Southwell, Paul; Pravin, Shalini; Buadromo, Eka; Carapetis, Jonathan; Tong, Steven; Steer, Andrew

    2014-03-24

    There are few data describing the microbiology and genetic typing of Staphylococcus aureus that cause infections in developing countries. In this study we observed S. aureus infections in Pacific Island nation of Fiji in both the community and hospital setting with an emphasis on clonal complex (CC) genotyping and antimicrobial susceptibility. S. aureus was commonly found in impetigo lesions of school children and was recovered from 57% of impetigo lesions frequently in conjunction with group A streptococcal infection. Methicillin-resistant S. aureus (MRSA) comprised 7% (20/299) of isolates and were all non-multi-resistant and all genotyped as CC1. In contrast, there was a diverse selection of 17 CCs among the 105 genotyped methicillin-susceptible S.aureus (MSSA) strains. Isolates of the rare, phylogenetically divergent and non-pigmented CC75 lineage (also called S. argenteus) were found in Fiji.From hospitalized patients the available 36 MRSA isolates from a 9-month period were represented by five CCs. The most common CCs were CC1 and CC239. CC1 is likely to be a community-acquired strain, reflecting what was found in the school children, whereas the CC239 is the very successful multi-drug resistant MRSA nosocomial lineage. Of 17 MSSA isolates, 59% carried genes for Panton-Valentine leukocidin. The S. aureus bacteraemia incidence rate of 50 per 100,000 population is among the highest reported in the literature and likely reflects the high overall burden of staphylococcal infections in this population. S. aureus is an important cause of disease in Fiji and there is considerable genotypic diversity in community skin infections in Fijian schoolchildren. Community acquired- (CA)- MRSA is present at a relatively low prevalence (6.7%) and was solely to CC1 (CA-MRSA). The globally successful CC239 is also a significant pathogen in Fiji.

  9. Evaluation of synergistic activity of bovine lactoferricin with antibiotics in corneal infection.

    Science.gov (United States)

    Oo, Thein Zaw; Cole, Nerida; Garthwaite, Linda; Willcox, Mark D P; Zhu, Hua

    2010-06-01

    The objectives of this study were to determine whether a synergistic effect could be obtained in vitro between bovine lactoferricin (B-LFcin) and antibiotics against Pseudomonas aeruginosa and Staphylococcus aureus isolates from ocular infections, and to evaluate the use of B-LFcin as an adjunct to the antibiotic treatment of corneal infection in vivo. Chequerboard and time-kill assays were performed to investigate the combined effects of B-LFcin and conventional antibiotics, including ciprofloxacin, ceftazidime and gentamicin, against 17 strains of P. aeruginosa (8) and S. aureus (9) isolated from ocular infection and inflammation, and 1 reference strain of S. aureus. Corneas of C57BL/6 mice were topically challenged with a multidrug-resistant strain of P. aeruginosa. Nine hours post-challenge, mice were treated topically and hourly with either vehicle, B-LFcin, ciprofloxacin or ciprofloxacin containing B-LFcin for 8 h. Corneas were then clinically examined, and bacterial numbers and levels of myeloperoxidase (MPO) evaluated. Synergy between B-LFcin and ciprofloxacin or ceftazidime was identified in most P. aeruginosa isolates, including multidrug-resistant strains, whereas no synergistic effect was seen between B-LFcin and gentamicin. Synergy was only observed with B-LFcin and ciprofloxacin against 2/10 S. aureus strains, and there was no synergy between B-LFcin and any of the other antibiotics tested. Combined B-LFcin and ciprofloxacin treatment significantly improved the clinical outcome, and reduced bacterial numbers and MPO in infected mouse corneas. B-LFcin alone was also able to reduce levels of MPO in infected corneas. These findings indicate that B-LFcin may have advantages as an adjunct therapy with both antimicrobial and anti-inflammatory properties in the treatment of corneal infection.

  10. Prevalence of Staphylococcus aureus in Shrimps in Tehran during 2013

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Soltan Dallal

    2015-12-01

    Full Text Available Background During fishing and transport, preservation and quality of fish products are importantas well as storage to prevent the growth of pathogenic and toxin producing bacteria.Staphylococcus aureus is one of the most common causes of sea food-borne diseases worldwidedue to contamination of food by preformed enterotoxins. The aim of this study was to compare theprevalence and contamination of S. aureus in marine and farmed shrimps in Tehran fishery center.Methods: A total of 300 samples, including 150 marine, 150 farmed shrimps were selected duringSeptember 2013 to December 2013. Isolation and identification of S. aureus from isolated sampleswere carried out according to conventional methods, and antibiotic susceptibility test wasperformed by modified Kirby-Bauer disc diffusion methodResults: The results of this study showed that 30% of marine and 20% off armed shrimps werecontaminated with S. aureus. The highest resistance was observed with penicillin and ampicillin,whereas 100% were sensitive to vancomycin, clindamycin, ciprofloxacin, and rifampin.Conclusions: Due to relatively high contamination of shrimp by S. aureus more attention shouldbe given during processing and manufacturing.

  11. Prevalence of Staphylococcus aureus in Shrimps in Tehran during 2013

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Soltan Dallal

    2016-02-01

    Full Text Available Background During fishing and transport, preservation and quality of fish products are importantas well as storage to prevent the growth of pathogenic and toxin producing bacteria.Staphylococcus aureus is one of the most common causes of sea food-borne diseases worldwidedue to contamination of food by preformed enterotoxins. The aim of this study was to compare theprevalence and contamination of S. aureus in marine and farmed shrimps in Tehran fishery center.Methods: A total of 300 samples, including 150 marine, 150 farmed shrimps were selected duringSeptember 2013 to December 2014. Isolation and identification of S. aureus from isolated sampleswere carried out according to conventional methods, and antibiotic susceptibility test wasperformed by modified Kirby-Bauer disc diffusion method.Results: The results of this study showed that 30% of marine and 20% off armed shrimps werecontaminated with S. aureus. The highest resistance was observed with penicillin and ampicillin,whereas 100% were sensitive to vancomycin, clindamycin, ciprofloxacin, and rifampin.Conclusions: Due to relatively high contamination of shrimp by S. aureus more attention shouldbe given during processing and manufacturing.

  12. Antibacterial Action of Curcumin against Staphylococcus aureus: A Brief Review

    Directory of Open Access Journals (Sweden)

    Sin-Yeang Teow

    2016-01-01

    Full Text Available Curcumin, the major constituent of Curcuma longa L. (Zingiberaceae family or turmeric, commonly used for cooking in Asian cuisine, is known to possess a broad range of pharmacological properties at relatively nontoxic doses. Curcumin is found to be effective against Staphylococcus aureus (S. aureus. As demonstrated by in vitro experiment, curcumin exerts even more potent effects when used in combination with various other antibacterial agents. Hence, curcumin which is a natural product derived from plant is believed to have profound medicinal benefits and could be potentially developed into a naturally derived antibiotic in the future. However, there are several noteworthy challenges in the development of curcumin as a medicine. S. aureus infections, particularly those caused by the multidrug-resistant strains, have emerged as a global health issue and urgent action is needed. This review focuses on the antibacterial activities of curcumin against both methicillin-sensitive S. aureus (MSSA and methicillin-resistant S. aureus (MRSA. We also attempt to highlight the potential challenges in the effort of developing curcumin into a therapeutic antibacterial agent.

  13. Detection of the enterotoxigenic genes (sei,sej) in Staphylococcus aureus isolates from bovine mastitis milk in the West Azerbaijan of Iran

    OpenAIRE

    Ahmady, Malahat; Kazemi, Sahar

    2012-01-01

    Staphylococcus aureus is a major causative pathogen of clinical and subclinical mastitis of dairy domestic ruminants. This organism produces a variety of extracellular toxins and virulence factors such as enterotoxin SEI and SEJ that contribute to its pathogenic potential. In this study 25 S. aureus isolates obtained from four dairy herds of Urmia region which is located in West Azerbaijan province in Iran. The tested isolates were identified on the basis of the cultural and biochemical prope...

  14. Staphylococcus aureus biofilms: recent developments in biofilm dispersal.

    Science.gov (United States)

    Lister, Jessica L; Horswill, Alexander R

    2014-01-01

    Staphylococcus aureus is a major cause of nosocomial and community-acquired infections and represents a significant burden on the healthcare system. S. aureus attachment to medical implants and host tissue, and the establishment of a mature biofilm, play an important role in the persistence of chronic infections. The formation of a biofilm, and encasement of cells in a polymer-based matrix, decreases the susceptibility to antimicrobials and immune defenses, making these infections difficult to eradicate. During infection, dispersal of cells from the biofilm can result in spread to secondary sites and worsening of the infection. In this review, we discuss the current understanding of the pathways behind biofilm dispersal in S. aureus, with a focus on enzymatic and newly described broad-spectrum dispersal mechanisms. Additionally, we explore potential applications of dispersal in the treatment of biofilm-mediated infections.

  15. The Pre - Eminence of Staphylococcus Aureus as The Causative ...

    African Journals Online (AJOL)

    A range of infections is caused by Staphylococcal organisms prominent among them are nosocomial superficial infections manifesting as abscesses, furuncles, and wound infections. The study objective is to determine the degree to which Staphylococcus aureus is a cause of such lesions in a tertiary health care institution ...

  16. Fresh garlic extract inhibits Staphylococcus aureus biofilm formation under chemopreventive and chemotherapeutic conditions

    Directory of Open Access Journals (Sweden)

    Panan Ratthawongjirakul

    2016-08-01

    Full Text Available Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA are the leading aetiological pathogens of nosocomial infections worldwide. These bacteria form biofilms on both biotic and abiotic surfaces causing biofilm-associated infections. Within the biofilm, these bacteria might develop persistent and antimicrobial resistant characteristics resulting in chronic infections and treatment failures. Garlic exhibits broad pharmaceutical properties and inhibitory activities against S. aureus. We investigated the effects of aqueous fresh garlic extract on biofilm formation in S. aureus ATCC25923 and MRSA strains under chemopreventive and chemotherapeutic conditions. The viable bacteria and biofilm levels were quantified through colony count and crystal violet staining, respectively. The use of fresh garlic extract under both conditions significantly inhibited biofilm formation in S. aureus strains ATCC25923 and MRSA. Garlic could be developed as either a prophylactic or therapeutic agent to manage S. aureus biofilm-associated infections.

  17. Evaluation of envelope glycoprotein E(rns) of an atypical bovine pestivirus as antigen in a microsphere immunoassay for the detection of antibodies against bovine viral diarrhea virus 1 and atypical bovine pestivirus.

    Science.gov (United States)

    Vijayaraghavan, Balaje; Xia, Hongyan; Harimoorthy, Rajiv; Liu, Lihong; Belák, Sándor

    2012-11-01

    Atypical bovine pestiviruses are related antigenically and phylogenetically to bovine viral diarrhea viruses (BVDV-1 and BVDV-2), and may cause the same clinical manifestations in animals. Glycoprotein E(rns) of an atypical bovine pestivirus Th/04_KhonKaen was produced in a baculovirus expression system and was purified by affinity chromatography. The recombinant E(rns) protein was used as an antigen in a microsphere immunoassay for the detection of antibodies against BVDV-1 and atypical bovine pestivirus. The diagnostic performance of the new method was evaluated by testing a total of 596 serum samples, and the assay was compared with enzyme-linked immunosorbent assay (ELISA). Based on the negative/positive cut-off median fluorescence intensity (MFI) value of 2800, the microsphere immunoassay had a sensitivity of 100% and specificity of 100% compared to ELISA. The immunoassay was able to detect antibodies against both BVDV-1 and the atypical pestivirus. This novel microsphere immunoassay has the potential to be multiplexed for simultaneous detection of antibodies against different bovine pathogens in a high-throughput and economical way. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Methicillin-resistant Staphylococcus aureus: a controversial food-borne pathogen.

    Science.gov (United States)

    Sergelidis, D; Angelidis, A S

    2017-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of severe healthcare-associated (HA) infections. Although during the last decade the incidence of HA invasive infections has dropped, the incidence of community-associated MRSA (CA-MRSA) infections has risen among the general population. Moreover, CA-MRSA, livestock-associated MRSA (LA-MRSA) and HA-MRSA (HA-MRSA) can be found in foods intended for human consumption. Several studies from different geographical areas have reported the presence of enterotoxin genes in several MRSA food isolates. Molecular typing studies have revealed genetic relatedness of these enterotoxigenic isolates with isolates incriminated in human infections. The contamination sources for foods, especially animal-origin foods, may be livestock as well as humans involved in animal husbandry and food-processing. Under favourable environmental conditions for growth and enterotoxin production, enterotoxigenic S. aureus isolates present in foods can cause staphylococcal food poisoning (SFP), irrespective of the contamination origin. Owing to the typically moderate clinical manifestations of SFP, the S. aureus strains responsible for SFP (cases or outbreaks) are frequently either not identified or not further characterized. Antimicrobial susceptibility testing is rarely performed, because administration of antimicrobial therapy is not required in the vast majority of cases. Staphylococcal food poisoning is the result of consumption of foods with preformed enterotoxins. Hence, similar to methicillin-sensitive enterotoxigenic S. aureus, enterotoxigenic MRSA can also act as food-borne pathogens upon favourable conditions for growth and enterotoxin production. The severity of the intoxication is not related to the antimicrobial resistance profile of the causative S. aureus strain and therefore MRSA food-borne outbreaks are not expected to be more severe. This review evaluates the potential of methicillin-resistant Staphylococcus

  19. Recent Progress in Cryopreservation of Bovine Oocytes

    Directory of Open Access Journals (Sweden)

    In-Sul Hwang

    2014-01-01

    Full Text Available Principle of oocyte cryoinjury is first overviewed and then research history of cryopreservation using bovine oocytes is summarized for the last two decades with a few special references to recent progresses. Various types of cryodevices have been developed to accelerate the cooling rate and applied to the oocytes from large domestic species enriched with cytoplasmic lipid droplets. Two recent approaches include the qualitative improvement of IVM oocytes prior to the vitrification and the short-term recovery culture of vitrified-warmed oocytes prior to the subsequent IVF. Supplementation of L-carnitine to IVM medium of bovine oocytes has been reported to reduce the amount of cytoplasmic lipid droplets and improve the cryotolerance of the oocytes, but it is still controversial whether the positive effect of L-carnitine is reproducible. Incidence of multiple aster formation, a possible cause for low developmental potential of vitrified-warmed bovine oocytes, was inhibited by a short-term culture of the postwarm oocytes in the presence of Rho-associated coiled-coil kinase (ROCK inhibitor. Use of an antioxidant α-tocopherol, instead of the ROCK inhibitor, also supported the revivability of the postwarm bovine oocytes. Further improvements of the vitrification procedure, combined with pre- and postvitrification chemical treatment, would overcome the high sensitivity of bovine oocytes to cryopreservation.

  20. Shedding of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus from adult and pediatric bathers in marine waters

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    Sinigalliano Christopher D

    2011-01-01

    Full Text Available Abstract Background Staphylococcus aureus including methicillin resistant S. aureus, MRSA, are human colonizing bacteria that commonly cause opportunistic infections primarily involving the skin in otherwise healthy individuals. These infections have been linked to close contact and sharing of common facilities such as locker rooms, schools and prisons Waterborne exposure and transmission routes have not been traditionally associated with S. aureus infections. Coastal marine waters and beaches used for recreation are potential locations for the combination of high numbers of people with close contact and therefore could contribute to the exposure to and infection by these organisms. The primary aim of this study was to evaluate the amount and characteristics of the shedding of methicillin sensitive S. aureus, MSSA and MRSA by human bathers in marine waters. Results Nasal cultures were collected from bathers, and water samples were collected from two sets of pools designed to isolate and quantify MSSA and MRSA shed by adults and toddlers during exposure to marine water. A combination of selective growth media and biochemical and polymerase chain reaction analysis was used to identify and perform limited characterization of the S. aureus isolated from the water and the participants. Twelve of 15 MRSA isolates collected from the water had identical genetic characteristics as the organisms isolated from the participants exposed to that water while the remaining 3 MRSA were without matching nasal isolates from participants. The amount of S. aureus shed per person corresponded to 105 to 106 CFU per person per 15-minute bathing period, with 15 to 20% of this quantity testing positive for MRSA. Conclusions This is the first report of a comparison of human colonizing organisms with bacteria from human exposed marine water attempting to confirm that participants shed their own colonizing MSSA and MRSA into their bathing milieu. These findings clearly

  1. Incidence of bovine clinical mastitis in Jammu region and antibiogram of isolated pathogens

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    Adil Majid Bhat

    2017-08-01

    Full Text Available Aim: This study was conducted to evaluate the incidence of clinical mastitis in bovines of Jammu region, to identify the infectious organisms responsible for it, and the antimicrobial sensitivity of isolated pathogens. Materials and Methods: The study was conducted on cases that were presented to the Medicine Division of Teaching Veterinary Clinical Complex, Faculty of Veterinary Sciences and Animal Husbandry, R.S. Pura, Jammu, Jammu and Kashmir. A total of 260 cases of bovines were presented from June 30, 2012, to July 01, 2013, out of which 30 cases were of clinical mastitis. The diagnosis of clinical mastitis was made on the basis of history and clinical examination of affected animals. Results: Animal and quarter-wise incidence of clinical mastitis were found to be 11.5% and 5.76%, respectively. Of the 23 isolates obtained, Staphylococcus aureus (60.87% was the most frequently isolated organism, followed by coagulase negative Staphylococci (13.04%, Streptococcus uberis (4.35%, Streptococcus dysgalactiae (8.69%, and Escherichia coli (13.04%. The antimicrobial sensitivity of isolates revealed maximum sensitivity to enrofloxacin, gentamicin, amoxicillin/ sulbactam, ceftriaxone/tazobactam, ceftizoxime, ampicillin/sulbactam and least sensitivity for oxytetracycline and penicillin. Conclusion: Staphylococcus spp. is the major causative agent of clinical mastitis in bovines of Jammu region. The causative agents of the clinical mastitis were most sensitive to enrofloxacin and gentamicin.

  2. Development of a multicomponent Staphylococcus aureus vaccine designed to counter multiple bacterial virulence factors

    Science.gov (United States)

    Anderson, Annaliesa S.; Miller, Alita A.; Donald, Robert G.K.; Scully, Ingrid L.; Nanra, Jasdeep S.; Cooper, David; Jansen, Kathrin U.

    2012-01-01

    Staphylococcus aureus is a major cause of healthcare-associated infections and is responsible for a substantial burden of disease in hospitalized patients. Despite increasingly rigorous infection control guidelines, the prevalence and corresponding negative impact of S. aureus infections remain considerable. Difficulties in controlling S. aureus infections as well as the associated treatment costs are exacerbated by increasing rates of resistance to available antibiotics. Despite ongoing efforts over the past 20 years, no licensed S. aureus vaccine is currently available. However, learnings from past clinical failures of vaccine candidates and a better understanding of the immunopathology of S. aureus colonization and infection have aided in the design of new vaccine candidates based on multiple important bacterial pathogenesis mechanisms. This review outlines important considerations in designing a vaccine for the prevention of S. aureus disease in healthcare settings. PMID:22922765

  3. Lung and pharyngeal abscess caused by enterotoxin G- and I-producing Staphylococcus aureus.

    Science.gov (United States)

    Barnett, S Y; Hattotuwa, K L; Teare, L

    2012-05-01

    We report a particularly serious case of extensive meticillin sensitive Staphylococcal lung and pharyngeal abscess. Our patient had no significant risk factors for severe infection. The detection of enterotoxin G and I here suggest that when present together, these toxins work synergistically to produce a more virulent strain of Staphylococcus aureus. Copyright © 2011. Published by Elsevier Ltd.

  4. Calcium and Magnesium Ions Are Membrane-Active against Stationary-Phase Staphylococcus aureus with High Specificity

    Science.gov (United States)

    Xie, Yuntao; Yang, Lihua

    2016-02-01

    Staphylococcus aureus (S. aureus) is notorious for its ability to acquire antibiotic-resistance, and antibiotic-resistant S. aureus has become a wide-spread cause of high mortality rate. Novel antimicrobials capable of eradicating S. aureus cells including antibiotic-resistant ones are thus highly desired. Membrane-active bactericides and species-specific antimicrobials are two promising sources of novel anti-infective agents for fighting against bacterial antibiotic-resistance. We herein show that Ca2+ and Mg2+, two alkaline-earth-metal ions physiologically essential for diverse living organisms, both disrupt model S. aureus membranes and kill stationary-phase S. aureus cells, indicative of membrane-activity. In contrast to S. aureus, Escherichia coli and Bacillus subtilis exhibit unaffected survival after similar treatment with these two cations, indicative of species-specific activity against S. aureus. Moreover, neither Ca2+ nor Mg2+ lyses mouse red blood cells, indicative of hemo-compatibility. This works suggests that Ca2+ and Mg2+ may have implications in targeted eradication of S. aureus pathogen including the antibiotic-resistant ones.

  5. Bioeconomic modeling of lactational antimicrobial treatment of new bovine subclinical intramammary infections caused by contagious pathogens

    DEFF Research Database (Denmark)

    Van den Borne, B. H. P.; Hisham Beshara Halasa, Tariq; Van Schaik, G.

    2010-01-01

    This study determined the direct and indirect epidemiologic and economic effects of lactational treatment of new bovine subclinical intramammary infections (IMI) caused by contagious pathogens using an existing bioeconomic model. The dynamic and stochastic model simulated the dynamics...... of uncured cows after 2 mo of infection. Model behavior was observed for variation in parameter input values. Compared with no lactational intervention, lactational intervention of new subclinical IMI resulted in fewer clinical flare ups, less transmission within the herd, and much lower combined total....... Changing the probability of cure resulted in a nonlinear change in the cumulative incidence of IMI cases and associated costs. Lactational treatment was able to prevent IMI epidemics in dairy herds at high transmission rates of Strep. uberis, Strep. dysgalactiae, and E. coli. Lactational treatment did...

  6. Antimicrobial activity of Lactobacillus salivarius and Lactobacillus fermentum against Staphylococcus aureus.

    Science.gov (United States)

    Kang, Mi-Sun; Lim, Hae-Soon; Oh, Jong-Suk; Lim, You-Jin; Wuertz-Kozak, Karin; Harro, Janette M; Shirtliff, Mark E; Achermann, Yvonne

    2017-03-01

    The increasing prevalence of methicillin-resistant Staphylococcus aureus has become a major public health threat. While lactobacilli were recently found useful in combating various pathogens, limited data exist on their therapeutic potential for S. aureus infections. The aim of this study was to determine whether Lactobacillus salivarius was able to produce bactericidal activities against S. aureus and to determine whether the inhibition was due to a generalized reduction in pH or due to secreted Lactobacillus product(s). We found an 8.6-log10 reduction of planktonic and a 6.3-log10 reduction of biofilm S. aureus. In contrast, the previously described anti-staphylococcal effects of L. fermentum only caused a 4.0-log10 reduction in planktonic S. aureus cells, with no effect on biofilm S. aureus cells. Killing of S. aureus was partially pH dependent, but independent of nutrient depletion. Cell-free supernatant that was pH neutralized and heat inactivated or proteinase K treated had significantly reduced killing of L. salivarius than with pH-neutralized supernatant alone. Proteomic analysis of the L. salivarius secretome identified a total of five secreted proteins including a LysM-containing peptidoglycan binding protein and a protein peptidase M23B. These proteins may represent potential novel anti-staphylococcal agents that could be effective against S. aureus biofilms. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Evaluation of expression of NorA efflux pump in ciprofloxacin resistant Staphylococcus aureus against hexahydroquinoline derivative by real-time PCR.

    Science.gov (United States)

    Pourmand, Mohammad Reza; Yousefi, Masoud; Salami, Seyed Alireza; Amini, Mohsen

    2014-01-01

    Staphylococcus aureus causes a wide variety of infections worldwide. Methicillin-resistant S. aureus is one of most common causes of nosocomial and community acquired infections. The fluoroquinolones are an important class of antibiotics that used to treat infections caused by S. aureus. Today, a significant increase in the rate of ciprofloxacin resistance in methicillin-resistant S. aureus strains is concerning. The norA efflux pump is considered as contributors to antibiotic resistance. Here, we aimed to evaluate the expression of norA efflux pump in the presence of hexahydroquinoline derivative in methicillin and ciprofloxacin resistant S. aureus. We were determined minimum inhibitory concentration of ciprofloxacin and hexahydroquinoline derivative and their combination by broth microdilution method against ciprofloxacin resistant S. aureus. The expression of the norA efflux pump gene was evaluated by quantitative Real-time PCR. This study showed that minimum inhibitory concentrations of ciprofloxacin in the presence of hexahydroquinoline derivative in comparison to ciprofloxacin were decreased. Quantitative Real-time PCR identified the increased expression of norA efflux pump gene in methicillin and ciprofloxacin resistant S. aureus strain. The increased expression of norA efflux pump gene may have resulted in the effort of S. aureus to survive. The results showed that the hexahydroquinoline derivative enhanced the antibacterial effect of ciprofloxacin against methicillin and ciprofloxacin resistant S. aureus. Therefore, the derivatives may be used as inhibitors of antibiotic resistance for combination therapy.

  8. Virulence potential of Staphylococcus aureus isolates from Buruli ulcer patients.

    Science.gov (United States)

    Amissah, Nana Ama; Chlebowicz, Monika A; Ablordey, Anthony; Tetteh, Caitlin S; Prah, Isaac; van der Werf, Tjip S; Friedrich, Alex W; van Dijl, Jan Maarten; Stienstra, Ymkje; Rossen, John W

    2017-06-01

    Buruli ulcer (BU) is a necrotizing infection of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. BU wounds may also be colonized with other microorganisms including Staphylococcus aureus. This study aimed to characterize the virulence factors of S. aureus isolated from BU patients. Previously sequenced genomes of 21 S. aureus isolates from BU patients were screened for the presence of virulence genes. The results show that all S. aureus isolates harbored on their core genomes genes for known virulence factors like α-hemolysin, and the α- and β-phenol soluble modulins. Besides the core genome virulence genes, mobile genetic elements (MGEs), i.e. prophages, genomic islands, pathogenicity islands and a Staphylococcal cassette chromosome (SCC) were found to carry different combinations of virulence factors, among them genes that are known to encode factors that promote immune evasion, superantigens and Panton-Valentine Leucocidin. The present observations imply that the S. aureus isolates from BU patients harbor a diverse repertoire of virulence genes that may enhance bacterial survival and persistence in the wound environment and potentially contribute to delayed wound healing. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

  9. Staphylococcus aureus α-toxin-dependent induction of host cell death by membrane-derived vesicles.

    Directory of Open Access Journals (Sweden)

    Bernard Thay

    Full Text Available Staphylococcus aureus causes a wide spectrum of infections in humans, ranging from superficial cutaneous infections, infections in the circum-oral region, to life-threatening bacteremia. It was recently demonstrated that Gram-positive organisms such as S. aureus liberate membrane-derived vesicles (MVs, which analogously to outer membrane vesicles (OMVs of Gram-negative bacteria can play a role in delivering virulence factors to host cells. In the present study we have shown that cholesterol-dependent fusion of S. aureus MVs with the plasma membrane represents a route for delivery of a key virulence factor, α-toxin (α-hemolysin; Hla to human cells. Most S. aureus strains produce this 33-kDa pore-forming protein, which can lyse a wide range of human cells, and induce apoptosis in T-lymphocytes. Our results revealed a tight association of biologically active α-toxin with membrane-derived vesicles isolated from S. aureus strain 8325-4. Concomitantly, α-toxin contributed to HeLa cell cytotoxicity of MVs, and was the main vesicle-associated protein responsible for erythrocyte lysis. In contrast, MVs obtained from an isogenic hla mutant were significantly attenuated with regards to both causing lysis of erythrocytes and death of HeLa cells. This is to our knowledge the first recognition of an S. aureus MV-associated factor contributing to host cell cytotoxicity.

  10. Gene expression-based classifiers identify Staphylococcus aureus infection in mice and humans.

    Directory of Open Access Journals (Sweden)

    Sun Hee Ahn

    Full Text Available Staphylococcus aureus causes a spectrum of human infection. Diagnostic delays and uncertainty lead to treatment delays and inappropriate antibiotic use. A growing literature suggests the host's inflammatory response to the pathogen represents a potential tool to improve upon current diagnostics. The hypothesis of this study is that the host responds differently to S. aureus than to E. coli infection in a quantifiable way, providing a new diagnostic avenue. This study uses Bayesian sparse factor modeling and penalized binary regression to define peripheral blood gene-expression classifiers of murine and human S. aureus infection. The murine-derived classifier distinguished S. aureus infection from healthy controls and Escherichia coli-infected mice across a range of conditions (mouse and bacterial strain, time post infection and was validated in outbred mice (AUC>0.97. A S. aureus classifier derived from a cohort of 94 human subjects distinguished S. aureus blood stream infection (BSI from healthy subjects (AUC 0.99 and E. coli BSI (AUC 0.84. Murine and human responses to S. aureus infection share common biological pathways, allowing the murine model to classify S. aureus BSI in humans (AUC 0.84. Both murine and human S. aureus classifiers were validated in an independent human cohort (AUC 0.95 and 0.92, respectively. The approach described here lends insight into the conserved and disparate pathways utilized by mice and humans in response to these infections. Furthermore, this study advances our understanding of S. aureus infection; the host response to it; and identifies new diagnostic and therapeutic avenues.

  11. Genetic Diversity of Staphylococcus aureus in Buruli Ulcer

    NARCIS (Netherlands)

    Amissah, Nana Ama; Glasner, Corinna; Ablordey, Anthony; Tetteh, Caitlin S.; Kotey, Nana Konama; Prah, Isaac; van der Werf, Tjip; Rossen, John W.; van Dijl, Jan Maarten; Stienstra, Ymkje

    Background Buruli ulcer (BU) is a necrotizing skin disease caused by Mycobacterium ulcerans. Previous studies have shown that wounds of BU patients are colonized with M. ulcerans and several other microorganisms, including Staphylococcus aureus, which may interfere with wound healing. The present

  12. Antibiotic resistance and molecular analysis of Staphylococcus aureus isolated from cow's milk and dairy products in northeast Brazil.

    Science.gov (United States)

    Silveira-Filho, Vladimir M; Luz, Isabelle S; Campos, Ana Paula F; Silva, Wellington M; Barros, Maria Paloma S; Medeiros, Elizabeth S; Freitas, Manuela F L; Mota, Rinaldo A; Sena, Maria J; Leal-Balbino, Tereza C

    2014-04-01

    This work aimed to assess the clonal distribution among 94 strains of Staphylococcus aureus isolated from cow's milk, raw cheese, and a milking machine in 12 dairy farms in northeast Brazil, by analyzing different typing methods and detecting resistance and toxigenic profiles. For the first time, isolates of this region were assessed simultaneously by the polymorphism of the 3'-end coa gene and 16S-23S rDNA, pulsed-field gel electrophoresis, antibiotic resistance phenotyping, and toxigenic arsenal. Although pulsed-field gel electrophoresis patterns showed a wider variation (discriminatory index 0.83) than the PCR-based methods, the internal transcribed spacer-PCR proved to be a useful and inexpensive procedure for conducting epidemiological surveys of S. aureus on a regional scale. Each dairy farm had its own resistance profile, and in two herds, 63% of the strains were multiresistant, probably due to the indiscriminate use of antibiotics in bovine mastitis treatment. No methicillin-resistant S. aureus strains were detected in this study; however, 93.6% of S. aureus strains harbored variable profiles of staphylococcal enterotoxin genes seg, seh, sei, and sej. Transcriptional analysis revealed that 53.3% of staphylococcal enterotoxin genes actually transcribed, pointing out the food poisoning risk of these dairy products to consumers in the region. Based on the detection of the most prevalent clones in a herd or region, appropriate antibiotic therapy and specific immunization can be used for the treatment and control of staphylococcal mastitis.

  13. Antibody-Based Agents in the Management of Antibiotic-Resistant Staphylococcus aureus Diseases

    Science.gov (United States)

    Speziale, Pietro; Rindi, Simonetta

    2018-01-01

    Staphylococcus aureus is a human pathogen that can cause a wide spectrum of diseases, including sepsis, pneumonia, arthritis, and endocarditis. Ineffective treatment of a number of staphylococcal infections with antibiotics is due to the development and spread of antibiotic-resistant strains following decades of antibiotic usage. This has generated renewed interest within the scientific community in alternative therapeutic agents, such as anti-S. aureus antibodies. Although the role of antibodies in the management of S. aureus diseases is controversial, the success of this pathogen in neutralizing humoral immunity clearly indicates that antibodies offer the host extensive protection. In this review, we report an update on efforts to develop antibody-based agents, particularly monoclonal antibodies, and their therapeutic potential in the passive immunization approach to the treatment and prevention of S. aureus infections. PMID:29533985

  14. Computational structural and functional analysis of hypothetical proteins of Staphylococcus aureus

    OpenAIRE

    Mohan, Ramadevi; Venugopal, Subhashree

    2012-01-01

    Genome sequencing projects has led to an explosion of large amount of gene products in which many are of hypothetical proteins with unknown function. Analyzing and annotating the functions of hypothetical proteins is important in Staphylococcus aureus which is a pathogenic bacterium that cause multiple types of diseases by infecting various sites in humans and animals. In this study, ten hypothetical proteins of Staphylococcus aureus were retrieved from NCBI and analyzed for their structural ...

  15. Humanized Mouse Models of Staphylococcus aureus Infection

    Directory of Open Access Journals (Sweden)

    Dane Parker

    2017-05-01

    Full Text Available Staphylococcus aureus is a successful human pathogen that has adapted itself in response to selection pressure by the human immune system. A commensal of the human skin and nose, it is a leading cause of several conditions: skin and soft tissue infection, pneumonia, septicemia, peritonitis, bacteremia, and endocarditis. Mice have been used extensively in all these conditions to identify virulence factors and host components important for pathogenesis. Although significant effort has gone toward development of an anti-staphylococcal vaccine, antibodies have proven ineffective in preventing infection in humans after successful studies in mice. These results have raised questions as to the utility of mice to predict patient outcome and suggest that humanized mice might prove useful in modeling infection. The development of humanized mouse models of S. aureus infection will allow us to assess the contribution of several human-specific virulence factors, in addition to exploring components of the human immune system in protection against S. aureus infection. Their use is discussed in light of several recently reported studies.

  16. PREVALENCE OF BOVINE FASCIOLOSIS AT THE IBADAN ...

    African Journals Online (AJOL)

    Ismail

    Bovine fasciolosis is a parasitic disease of cattle caused by trematodes usually. Fasciola gigantic ... and impaired fertility [6,7]. The value of the .... especially males with good body condition, are transported to these cities with higher population ...

  17. Another cause of chest pain: Staphylococcus aureus sternal osteomyelitis in an otherwise healthy adult

    Directory of Open Access Journals (Sweden)

    Vacek TP

    2014-09-01

    Full Text Available Thomas P Vacek, Shahnaz Rehman, Shipeng Yu, Ankush Moza, Ragheb Assaly Department of Internal Medicine, The University of Toledo Medical Center, Toledo OH, USAAbstract: Chest pain requires a detailed differential diagnosis with good history-taking skills to differentiate between cardiogenic and noncardiogenic causes. Moreover, when other symptoms such as fever and elevated white blood cell count are involved, it may be necessary to consider causes that include infectious sources. A 53-year-old female with no significant past medical history returned to the hospital with recurrent complaints of chest pain that was constant, substernal, reproducible, and exacerbated with inspiration and expiration. The chest pain was thought to be noncardiogenic, as electrocardiography did not demonstrate changes, and cardiac enzymes were found to be negative for signs of ischemia. The patient's blood cultures were analyzed from a previous admission and were shown to be positive for Staphylococcus aureus. The patient was started empirically on vancomycin, which was later switched to ceftriaxone as the bacteria were more sensitive to this antibiotic. A transthoracic echocardiogram did not demonstrate any vegetation or signs of endocarditis. There was a small right pleural effusion discovered on X-ray. Therefore, computed tomography as well as magnetic resonance imaging of the chest were performed, and showed osteomyelitis of the chest. The patient was continued on intravenous ceftriaxone for a total of 6 weeks. Tests for HIV, hepatitis A, B, and C were all found to be negative. The patient had no history of childhood illness, recurrent infections, or previous trauma to the chest, and had had no recent respiratory infections, pneumonia, or any underlying lung condition. Hence, her condition was thought to be a case of primary sternal osteomyelitis without known cause.Keywords: substernal, pleuritic, myocardial infarction, differential

  18. Antibiotic-mediated selection of quorum-sensing-negative Staphylococcus aureus

    DEFF Research Database (Denmark)

    Paulander, Wilhelm Erik Axel; Varming, Anders Nissen; Bæk, Kristoffer Torbjørn

    2012-01-01

    of glycopeptide resistance greater than those of other strains. We show here that agr-negative strains have a fitness advantage over agr-positive strains in the presence of sublethal concentrations of some antibiotics and that the fitness defect of agr-positive cells is caused by antibiotic-mediated expression...... expression. We demonstrate that the presence of the agr locus imposes a fitness cost on S. aureus that is mediated by the expression of RNAIII. Further, we show that exposure to sublethal levels of the antibiotics ciprofloxacin, mupirocin, and rifampin, each targeting separate cellular functions, markedly...... increases the agr-mediated fitness cost by inducing the expression of RNAIII. Thus, the extensive use of antibiotics in hospitals may explain why agr-negative variants are frequently isolated from hospital-acquired S. aureus infections but rarely found among community-acquired S. aureus strains. Importantly...

  19. Numerical Chromosome Errors in Day 7 Somatic Nuclear Transfer Bovine Blastocysts

    DEFF Research Database (Denmark)

    Booth, Paul J.; VIUFF, Dorte; Tan, Shijian

    2002-01-01

    Day 7 bovine somatic nuclear transfer (NT) embryos reconstructed from granulosa cells were examined for numerical chromosome aberrations as a potential cause of the high embryonic and fetal loss observed in such embryos after transfer. The NT embryos were reconstructed using a zona-free manipulat......Day 7 bovine somatic nuclear transfer (NT) embryos reconstructed from granulosa cells were examined for numerical chromosome aberrations as a potential cause of the high embryonic and fetal loss observed in such embryos after transfer. The NT embryos were reconstructed using a zona...

  20. Relationship between Vancomycin-Resistant Staphylococcus aureus, Vancomycin-Intermediate S. aureus, High Vancomycin MIC, and Outcome in Serious S. aureus Infections

    OpenAIRE

    Holmes, Natasha E.; Johnson, Paul D. R.; Howden, Benjamin P.

    2012-01-01

    Vancomycin has been used successfully for over 50 years for the treatment of Staphylococcus aureus infections, particularly those involving methicillin-resistant S. aureus. It has proven remarkably reliable, but its efficacy is now being questioned with the emergence of strains of S. aureus that display heteroresistance, intermediate resistance, and, occasionally, complete vancomycin resistance. More recently, an association has been established between poor outcome and infections with strain...

  1. Increasing incidence but decreasing in-hospital mortality of adult Staphylococcus aureus bacteraemia between 1981 and 2000

    DEFF Research Database (Denmark)

    Benfield, Thomas; Espersen, F; Frimodt-Møller, N

    2007-01-01

    Staphylococcus aureus is a leading cause of bacteraemia. This study analysed temporal trends from 18,702 adult cases of S. aureus bacteraemia in Denmark between 1981 and 2000. After stratification for mode of acquisition, 57% of cases were hospital-acquired (HA), 28% were community-acquired (CA...... associated with S. aureus bacteraemia declined significantly between 1981 and 2000, but incidence rates doubled, so that the total number of deaths increased. These data emphasise the public health importance of S. aureus bacteraemia and the need for further preventive measures and improved care in order...

  2. Genomic investigation of Staphylococcus aureus isolates from bulk tank milk and dairy cows with clinical mastitis.

    Science.gov (United States)

    Ronco, Troels; Klaas, Ilka C; Stegger, Marc; Svennesen, Line; Astrup, Lærke B; Farre, Michael; Pedersen, Karl

    2018-02-01

    Staphylococcus aureus is one of the most common pathogens that cause mastitis in dairy cows. Various subtypes, virulence genes and mobile genetic elements have been associated with isolates from bulk tank milk and clinical mastitis. So far, no Danish cattle associated S. aureus isolates have been whole-genome sequenced and further analyzed. Thus, the main objective was to investigate the population structure and genomic content of isolates from bulk tank milk and clinical mastitis, using whole-genome sequencing. This may reveal the origin of strains that cause clinical mastitis. S. aureus isolates from bulk tank milk (n = 94) and clinical mastitis (n = 63) were collected from 91 and 24 different farms, respectively and whole-genome sequenced. The genomic content was analyzed and a phylogenetic tree based on single nucleotide polymorphisms was constructed. In general, the isolates from both bulk tank milk and clinical mastitis were of similar genetic background. This suggests that dairy cows are natural carriers of the S. aureus subtypes that cause clinical mastitis if the right conditions are present and that a broad range of subtypes cause mastitis. A phylogenetic cluster that mostly consisted of ST151 isolates carried three mobile genetic elements that were primarily found in this group. The prevalence of resistance genes was generally low. However, the first ST398 methicillin resistant S. aureus isolate from a Danish dairy cow with clinical mastitis was detected. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Toll-Like Receptor 2 Stimulation of Osteoblasts Mediates Staphylococcus Aureus Induced Bone Resorption and Osteoclastogenesis through Enhanced RANKL

    Science.gov (United States)

    Kassem, Ali; Lindholm, Catharina; Lerner, Ulf H

    2016-01-01

    Severe Staphylococcus aureus (S. aureus) infections pose an immense threat to population health and constitute a great burden for the health care worldwide. Inter alia, S. aureus septic arthritis is a disease with high mortality and morbidity caused by destruction of the infected joints and systemic bone loss, osteoporosis. Toll-Like receptors (TLRs) are innate immune cell receptors recognizing a variety of microbial molecules and structures. S. aureus recognition via TLR2 initiates a signaling cascade resulting in production of various cytokines, but the mechanisms by which S. aureus causes rapid and excessive bone loss are still unclear. We, therefore, investigated how S. aureus regulates periosteal/endosteal osteoclast formation and bone resorption. S. aureus stimulation of neonatal mouse parietal bone induced ex vivo bone resorption and osteoclastic gene expression. This effect was associated with increased mRNA and protein expression of receptor activator of NF-kB ligand (RANKL) without significant change in osteoprotegerin (OPG) expression. Bone resorption induced by S. aureus was abolished by OPG. S. aureus increased the expression of osteoclastogenic cytokines and prostaglandins in the parietal bones but the stimulatory effect of S. aureus on bone resorption and Tnfsf11 mRNA expression was independent of these cytokines and prostaglandins. Stimulation of isolated periosteal osteoblasts with S. aureus also resulted in increased expression of Tnfsf11 mRNA, an effect lost in osteoblasts from Tlr2 knockout mice. S. aureus stimulated osteoclastogenesis in isolated periosteal cells without affecting RANKL-stimulated resorption. In contrast, S. aureus inhibited RANKL-induced osteoclast formation in bone marrow macrophages. These data show that S. aureus enhances bone resorption and periosteal osteoclast formation by increasing osteoblast RANKL production through TLR2. Our study indicates the importance of using different in vitro approaches for studies of how S

  4. Cross-Talk between Staphylococcus aureus and Other Staphylococcal Species via the agr Quorum Sensing System

    DEFF Research Database (Denmark)

    Canovas de la Nuez, Jaime; Baldry, Mara; Bojer, Martin S

    2016-01-01

    -inducing peptides (AIPs) sensed by AgrC, a two component histidine kinase. agr loci are found also in other staphylococcal species and for Staphylococcus epidermidis, the encoded AIP represses expression of agr regulated virulence genes in S. aureus. In this study we aimed to better understand the interaction...... between staphylococci and S. aureus, and show that this interaction may eventually lead to the identification of new anti-virulence candidates to target S. aureus infections. Here we show that culture supernatants of 37 out of 52 staphylococcal isolates representing 17 different species inhibit S. aureus...... suggesting that agr is an inter-species communication system. Based on these results we speculate that interactions between S. aureus and other colonizing staphylococci will significantly influence the ability of S. aureus to cause infection, and we propose that other staphylococci are potential sources...

  5. Genotypic and phenotypic detection of capsular polysaccharides in Staphylococcus aureus isolated from bovine intramammary infections in Argentina

    Directory of Open Access Journals (Sweden)

    C. Camussone

    2012-09-01

    Full Text Available Staphylococcus aureus (n=157 isolated from intramammary infections in Argentine dairy areas were evaluated for presence of cap5 and cap8 loci. Isolates carrying cap5 and cap8 were serotyped using specific antisera. Sixty four percent of the isolates were genotyped as cap5 or cap8 and 50% of them expressed CP5 or 8.

  6. ω-Hydroxyemodin Limits Staphylococcus aureus Quorum Sensing-Mediated Pathogenesis and Inflammation

    Science.gov (United States)

    Daly, Seth M.; Elmore, Bradley O.; Kavanaugh, Jeffrey S.; Triplett, Kathleen D.; Figueroa, Mario; Raja, Huzefa A.; El-Elimat, Tamam; Crosby, Heidi A.; Femling, Jon K.; Cech, Nadja B.; Horswill, Alexander R.; Oberlies, Nicholas H.

    2015-01-01

    Antibiotic-resistant pathogens are a global health threat. Small molecules that inhibit bacterial virulence have been suggested as alternatives or adjuncts to conventional antibiotics, as they may limit pathogenesis and increase bacterial susceptibility to host killing. Staphylococcus aureus is a major cause of invasive skin and soft tissue infections (SSTIs) in both the hospital and community settings, and it is also becoming increasingly antibiotic resistant. Quorum sensing (QS) mediated by the accessory gene regulator (agr) controls virulence factor production essential for causing SSTIs. We recently identified ω-hydroxyemodin (OHM), a polyhydroxyanthraquinone isolated from solid-phase cultures of Penicillium restrictum, as a suppressor of QS and a compound sought for the further characterization of the mechanism of action. At concentrations that are nontoxic to eukaryotic cells and subinhibitory to bacterial growth, OHM prevented agr signaling by all four S. aureus agr alleles. OHM inhibited QS by direct binding to AgrA, the response regulator encoded by the agr operon, preventing the interaction of AgrA with the agr P2 promoter. Importantly, OHM was efficacious in a mouse model of S. aureus SSTI. Decreased dermonecrosis with OHM treatment was associated with enhanced bacterial clearance and reductions in inflammatory cytokine transcription and expression at the site of infection. Furthermore, OHM treatment enhanced the immune cell killing of S. aureus in vitro in an agr-dependent manner. These data suggest that bacterial disarmament through the suppression of S. aureus QS may bolster the host innate immune response and limit inflammation. PMID:25645827

  7. Staphylococcus aureus ocular infection: methicillin-resistance, clinical features, and antibiotic susceptibilities.

    Directory of Open Access Journals (Sweden)

    Chih-Chun Chuang

    Full Text Available BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA infection is an important public health issue. The study aimed to determine the prevalence of ocular infections caused by MRSA and to identify the clinical characteristics and antibiotic susceptibility of ocular MRSA infections by comparing those of ocular methicillin-sensitive S. aureus (MSSA infections. METHODOLOGY/PRINCIPAL FINDINGS: The medical records of the patients (n = 519 with culture-proven S. aureus ocular infections seen between January 1, 1999 and December 31, 2008 in Chang Gung Memorial Hospital were retrospectively reviewed. Two hundred and seventy-four patients with MRSA and 245 with MSSA ocular infections were identified. The average rate of MRSA in S. aureus infections was 52.8% and the trend was stable over the ten years (P value for trend  = 0.228. MRSA ocular infections were significantly more common among the patients with healthcare exposure (P = 0.024, but 66.1% (181/274 patients with MRSA ocular infections had no healthcare exposure. The most common clinical presentation for both MRSA and MSSA ocular infections was keratitis; MRSA and MSSA caused a similar disease spectrum except for lid infections. MRSA was significantly more resistant than MSSA to clindamycin, erythromycin and sulfamethoxazole/trimethoprim (all P<0.001. CONCLUSIONS/SIGNIFICANCE: We demonstrated a paralleled trend of ocular MRSA infection in a highly prevalent MRSA country by hospital-based survey. Except for lid disorder, MRSA shared similar spectrum of ocular pathology with MSSA. Since S. aureus is a common ocular pathogen, our results raise clinician's attention to the existence of highly prevalent MRSA.

  8. DNA carryover in milk samples from routine milk recording used for PCR-based diagnosis of bovine Staphylococcus aureus mastitis

    DEFF Research Database (Denmark)

    Mahmmod, Yasser Saadeldien Ibrahim; Klaas, Ilka Christine; Enevoldsen, Carsten

    2017-01-01

    milking order must be considered in mastitis control efforts. We suggest a practical interpretation of PCR results: cows with a Ct-value 37 and 32-37 can be labeled "very likely to be negative for Staph. aureus...

  9. Emergence of a Staphylococcus aureus Clone Resistant to Mupirocin and Fusidic Acid Carrying Exotoxin Genes and Causing Mainly Skin Infections.

    Science.gov (United States)

    Doudoulakakis, Anastassios; Spiliopoulou, Iris; Spyridis, Nikolaos; Giormezis, Nikolaos; Kopsidas, John; Militsopoulou, Maria; Lebessi, Evangelia; Tsolia, Maria

    2017-08-01

    Skin and soft tissue infections (SSTIs) caused by mupirocin-resistant Staphylococcus aureus strains have recently increased in number in our settings. We sought to evaluate the characteristics of these cases over a 43-month period. Data for all community-acquired staphylococcal infections caused by mupirocin-resistant strains were retrospectively reviewed. Genes encoding products producing high-level resistance (HLR) to mupirocin ( mupA ), fusidic acid resistance ( fusB ), resistance to macrolides and lincosamides ( ermC and ermA ), Panton-Valentine leukocidin (PVL) ( lukS/lukF -PV), exfoliative toxins ( eta and etb ), and fibronectin binding protein A ( fnbA ) were investigated by PCRs in 102 selected preserved strains. Genotyping was performed by SCC mec and agr typing, whereas clonality was determined by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). A total of 437 cases among 2,137 staphylococcal infections were recorded in 2013 to 2016; they were all SSTIs with the exception of 1 case of primary bacteremia. Impetigo was the predominant clinical entity (371 cases [84.9%]), followed by staphylococcal scalded skin syndrome (21 cases [4.8%]), and there were no abscesses. The number of infections detected annually increased during the study years. All except 3 isolates were methicillin susceptible. The rates of HLR to mupirocin and constitutive resistance to clindamycin were 99% and 20.1%, respectively. Among the 102 tested strains, 100 (98%) were mupA positive and 97 (95%) were fusB positive, 26/27 clindamycin-resistant strains (96.3%) were ermA positive, 83 strains (81.4%) were lukS/lukF positive, 95 (93%) carried both eta and etb genes, and 99 (97%) were fnbA positive. Genotyping of methicillin-sensitive S. aureus (MSSA) strains revealed that 96/99 (96.7%) belonged to one main pulsotype, pulsotype 1, classified as sequence type 121 (ST121). The emergence of a single MSSA clone (ST121) causing impetigo was documented. Resistance to

  10. Testing the sensitivity of Staphylococcus aureus antibiotics

    Directory of Open Access Journals (Sweden)

    Marioara Nicoleta FILIMON

    2009-11-01

    Full Text Available This study has in view to establish and test the sensitivity of Staphylococcus aureus antibiotics. There are different injuries caused by superficial skin infections: from simple pimples to infections that endanger our lives, like an abscess, furuncle septicemia, meningitis, toxic food, urinary tract infection at sexually active young women. Samples have been taken from 30 people with staphylococcus infections. They were nineteen women and eleven men, between the age of 2 and 79. During this study some antibiograms have been made, based on pharyngeal exudates, acne secretion and urine culture. It has been established that the most efficient recommended antibiotics are: oxacilin, erythromycin, rifampicin and ciprofloxacin. The penicillin turned out to be less efficient to remove and destroy the Staphylococcus aureus species.

  11. Environmental contamination with Staphylococcus aureus at a large, Midwestern university campus.

    Science.gov (United States)

    Thapaliya, Dipendra; Taha, Mohammed; Dalman, Mark R; Kadariya, Jhalka; Smith, Tara C

    2017-12-01

    Staphylococcus aureus can cause minor to severe life-threatening infections. The changing epidemiology of S. aureus is of public health concern due to the emergence of multi-drug resistant (MDR) strains. Environmental surfaces play a crucial role in the transmission of S. aureus. The objective of this study was to examine environmental contamination and molecular characteristics of S. aureus in health professional-associated (HPA) and non-health professional-associated (NHPA) buildings at a large university. A total of 152 environmental surface samples were collected from two HPA and two NHPA campus buildings. Bacterial culture and diagnostics were done using standard microbiology methods. Polymerase chain reaction was conducted to detect mecA and PVL genes. All isolates were spa typed. A subset of isolates was characterized via multi-locus sequence typing (MLST). All S. aureus isolates were tested for antibiotic susceptibility. The overall contamination of S. aureus and methicillin-resistant S. aureus (MRSA) was 22.4% (34/152) and 5.9% (9/152) respectively. Similar prevalence of contamination was found in HPA and NHPA buildings. A total of 17 different spa types were detected among 34 S. aureus isolates. The majority of the MRSA isolates belonged to clonal complex (CC) 8. One isolate was positive for PVL. Eleven different sequence types (STs) were detected from 17 tested isolates. ST8 was the most common. Twelve isolates (35.3%) were MDR. Almost 27% (9/34) of the isolates were MRSA. The highest contamination of S. aureus was found in high hand-touch areas such as door knobs, suggesting that human interaction in crowded environments such as academic institutions plays a crucial role in S. aureus/MRSA transmission via inanimate objects. Additionally, more than one-third of the isolates were MDR. These data reinforce the need to implement effective prevention strategies outside the healthcare setting to decrease the incidence of drug-resistant S. aureus infections

  12. An outbreak of food poisoning due to egg yolk reaction-negative Staphylococcus aureus.

    Science.gov (United States)

    Miwa, N; Kawamura, A; Masuda, T; Akiyama, M

    2001-03-20

    An outbreak of staphylococcal food poisoning due to an egg yolk (EY) reaction-negative strain occurred in Japan. Twenty-one of 53 dam construction workers who ate boxed lunches prepared at their company cafeteria became ill, and eight required hospital treatment. The outbreak showed a typical incubation time (1.5-4 h with a median time of 2.7 h) and symptoms (vomiting and diarrhea) of staphylococcal food poisoning. Staphylococcus aureus, which produces staphylococcal enterotoxin (SE) A, was isolated from four fecal specimens of eight patients tested. Scrambled egg in the boxed lunches contained 20-40 ng/g of SEA, and 3.0 x 10(9)/g of viable S. aureus cells that produced this toxin. All isolates from patients and the food were EY reaction-negative, coagulase type II, and showed the same restriction fragment length polymorphism (RFLP) pattern. We concluded that the outbreak was caused by scrambled egg contaminated with EY reaction-negative S. aureus. In Japan, outbreaks of staphylococcal food poisoning are mainly caused by EY reaction-positive S. aureus, and EY reaction-negative colonies grown on agar plates containing EY are usually not analyzed further for detection of S. aureus. The present outbreak suggested that EY reaction-negative isolates should be subjected to further analysis to detect the causative agents of staphylococcal food poisoning.

  13. Antimicrobial activity of some sulfonamide derivatives on clinical isolates of Staphylococus aureus

    Directory of Open Access Journals (Sweden)

    Bekdemir Yunus

    2008-08-01

    Full Text Available Abstract Background Staphylococcus aureus is a non-motile, gram positive, non-sporforming, facultative anaerobic microorganism. It is one of the important bacteria as a potential pathogen specifically for nosocomial infections. The sulfonamide derivative medicines are preferred to cure infection caused by S. aureus due to methicillin resistance. Methods Antimicrobial activity of four sulfonamide derivatives have been investigated against 50 clinical isolates of S. aureus and tested by using MIC and disc diffusion methods. 50 clinical isolate which collected from specimens of patients who are given medical treatment in Ondokuz Mayis University Medical School Hospital. A control strain of S. aureus ATCC 29213 was also tested. Results The strongest inhibition was observed in the cases of I [N-(2-hydroxy-4-nitro-phenyl-4-methyl-benzensulfonamid], and II [N-(2-hydroxy-5-nitro-phenyl-4-methyl-benzensulfonamid] against S. aureus. Compound I [N-(2-hydroxy-4-nitro-phenyl-4-methyl-benzensulfonamid] showed higher effect on 21 S. aureus MRSAisolates than oxacillin antibiotic. Introducing an electron withdrawing on the ring increased the antimicrobial activity remarkably. Conclusion This study may help to suggest an alternative possible leading compound for development of new antimicrobial agents against MRSA and MSSA resistant S. aureus. It was also shown here that that clinical isolates of 50 S. aureus have various resistance patterns against to four sulfonamide derivatives. It may also be emphasized here that in vitro antimicrobial susceptibility testing results for S. aureus need standardization with further studies and it should also have a correlation with in vivo therapeutic response experiments.

  14. A longitudinal study on transmission of Staphylococcus aureus genotype B in Swiss communal dairy herds.

    Science.gov (United States)

    van den Borne, Bart H P; Graber, Hans U; Voelk, Verena; Sartori, Carlotta; Steiner, Adrian; Haerdi-Landerer, M Christina; Bodmer, Michèle

    2017-01-01

    Staphylococcus aureus is a common mastitis causing pathogen of dairy cattle. Several S. aureus genotypes exist, of which genotype B (GTB) is highly prevalent in Swiss dairy herds. Dairy farming in mountainous regions of Switzerland is characterised by the movement of dairy cattle to communal pasture-based operations at higher altitudes. Cows from different herds of origin share pastures and milking equipment for a period of 2 to 3 months during summer. The aim of this longitudinal observational study was to quantify transmission of S. aureus GTB in communal dairy operations. Cows (n=551) belonging to 7 communal operations were sampled at the beginning and end of the communal period. Transmission parameter β was estimated using a Susceptible-Infectious-Susceptible (SIS) model. The basic reproduction ratio R 0 was subsequently derived using previously published information about the duration of infection. Mean transmission parameter β was estimated to be 0.0232 (95% CI: 0.0197-0.0274). R 0 was 2.6 (95% CI: 2.2-3.0), indicating that S. aureus GTB is capable of causing major outbreaks in Swiss communal dairy operations. This study emphasized the contagious behaviour of S. aureus GTB. Mastitis management in communal dairy operations should be optimized to reduce S. aureus GTB transmission between cows and back to their herds of origin. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Comparative Efficacy of Ceftaroline with Linezolid against Staphylococcus Aureus and Methicillin Resistant Staphylococcus Aureus

    International Nuclear Information System (INIS)

    Hafeez, A.; Munir, T.; Rehman, S.; Najeeb, S.; Gilani, M.; Latif, M.; Ansari, M.; Saad, N.

    2015-01-01

    Objective:To compare the in vitro antimicrobial efficacy of ceftaroline with linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. Study Design: Quasi-experimental study. Place and Duration of Study: Microbiology Department, Army Medical College, Rawalpindi, from January to December 2013. Methodology: Clinical samples from respiratory tract, blood, pus and various catheter tips routinely received in the Department of Microbiology, Army Medical College, Rawalpindi were innoculated on blood and MacConkey agar. Staphylococcus aureus was identified by colony morphology, Gram reaction, catalase test and coagulase test. Methicillin resistant Staphylococcus aureus detection was done by modified Kirby Bauer disc diffusion method using cefoxitin disc (30g) and the isolates were considered methicillin resistant if the zone of inhibition around cefoxitin disc was /sup 2/ 21 mm. Bacterial suspensions of 56 Staphylococcus aureus isolates and 50 MRSA isolates were prepared, which were standardized equal to 0.5 McFarland's turbidity standard and inoculated on Mueller-Hinton agar plates followed by application of ceftaroline and linezolid disc (Oxoid, UK), according to manufacturer's instructions. The plates were then incubated at 37 Degree C aerobically for 18 - 24 hours. Diameters of inhibition zone were measured and interpretated as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Out of 106 isolates all of the 56 Staphylococcus aureus (100%) were sensitive to ceftaroline and linezolid. However, out of 50 methicillin resistant Staphylococcus aureus, 48 (96%) were sensitive to ceftaroline whereas, 49 (98%) were sensitive to linezolid. Conclusion: Ceftaroline is equally effective as linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. (author)

  16. Tracing and inhibiting growth of Staphylococcus aureus in barbecue cheese production after product recall.

    Science.gov (United States)

    Johler, S; Zurfluh, K; Stephan, R

    2016-05-01

    Staphylococcal food poisoning is one of the most prevalent causes of foodborne intoxication worldwide. It is caused by ingestion of enterotoxins formed by Staphylococcus aureus during growth in the food matrix. Following a recall of barbecue cheese due to the detection of staphylococcal enterotoxins in Switzerland in July 2015, we analyzed the production process of the respective dairy. Although most cheese-making processes involve acidification to inhibit the growth of pathogenic bacteria, barbecue cheese has to maintain a pH >6.0 to prevent undesired melting of the cheese. In addition, the dairy decided to retain the traditional manual production process of the barbecue cheese. In this study, therefore, we aimed to (1) trace Staph. aureus along the barbecue cheese production process, and (2) develop a sustainable strategy to inhibit growth of Staph. aureus and decrease the risk of staphylococcal food poisoning without changing the traditional production process. To this end, we traced Staph. aureus in a step-wise blinded process analysis on 4 different production days using spa (Staphylococcus protein A gene) typing, DNA microarray profiling, and pulsed-field gel electrophoresis analysis. We subsequently selected a new starter culture and used a model cheese production including a challenge test assay to assess its antagonistic effect on Staph. aureus growth, as well as its sensory and technological implications. We detected Staph. aureus in 30% (37/124) of the collected samples taken from the barbecue cheese production at the dairy. This included detection of Staph. aureus in the final product on all 4 production days, either after enrichment or using quantitative detection. We traced 2 enterotoxigenic Staph. aureus strains (t073/CC45 and t282/CC45) colonizing the nasal cavity and the forearms of the cheesemakers to the final product. In the challenge test assay, we were able to show that the new starter culture inhibited growth of Staph. aureus while meeting

  17. Staphylococcus aureus hyaluronidase is a CodY-regulated virulence factor.

    Science.gov (United States)

    Ibberson, Carolyn B; Jones, Crystal L; Singh, Shweta; Wise, Matthew C; Hart, Mark E; Zurawski, Daniel V; Horswill, Alexander R

    2014-10-01

    Staphylococcus aureus is a Gram-positive pathogen that causes a diverse range of bacterial infections. Invasive S. aureus strains secrete an extensive arsenal of hemolysins, immunomodulators, and exoenzymes to cause disease. Our studies have focused on the secreted enzyme hyaluronidase (HysA), which cleaves the hyaluronic acid polymer at the β-1,4 glycosidic bond. In the study described in this report, we have investigated the regulation and contribution of this enzyme to S. aureus pathogenesis. Using the Nebraska Transposon Mutant Library (NTML), we identified eight insertions that modulate extracellular levels of HysA activity. Insertions in the sigB operon, as well as in genes encoding the global regulators SarA and CodY, significantly increased HysA protein levels and activity. By altering the availability of branched-chain amino acids, we further demonstrated CodY-dependent repression of HysA activity. Additionally, through mutation of the CodY binding box upstream of hysA, the repression of HysA production was lost, suggesting that CodY is a direct repressor of hysA expression. To determine whether HysA is a virulence factor, a ΔhysA mutant of a community-associated methicillin-resistant S. aureus (CA-MRSA) USA300 strain was constructed and found to be attenuated in a neutropenic, murine model of pulmonary infection. Mice infected with this mutant strain exhibited a 4-log-unit reduction in bacterial burden in their lungs, as well as reduced lung pathology and increased levels of pulmonary hyaluronic acid, compared to mice infected with the wild-type, parent strain. Taken together, these results indicate that S. aureus hyaluronidase is a CodY-regulated virulence factor. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  18. Multidrug efflux pumps in Staphylococcus aureus and their clinical implications.

    Science.gov (United States)

    Jang, Soojin

    2016-01-01

    Antibiotic resistance is rapidly spreading among bacteria such as Staphylococcus aureus, an opportunistic bacterial pathogen that causes a variety of diseases in humans. For the last two decades, bacterial multidrug efflux pumps have drawn attention due to their potential association with clinical multidrug resistance. Numerous researchers have demonstrated efflux-mediated resistance in vitro and in vivo and found novel multidrug transporters using advanced genomic information about bacteria. This article aims to provide a concise summary of multidrug efflux pumps and their important clinical implications, focusing on recent findings concerning S. aureus efflux pumps.

  19. Immunological role of nasal staphylococcus aureus carriage in patients with persistent allergic rhinitis

    Directory of Open Access Journals (Sweden)

    Mohamed Yousif Atia

    2008-10-01

    Full Text Available Nasal carriage of staphylococcus aureus (S.aureus exerts immunomodulatory effect in patients with atopic dermatitis and it may contribute to airway inflammation and allergic response in patients with allergic rhinitis. We Aim to investigate the frequency of nasal S.aureus carriage in patients with persistent allergic rhinitis and its possible influence on their symptoms and immune markers. We chosed 20 non smoker patients with house dust mite (HDM allergy causing allergic rhinitis and 20 non smoker healthy subjects matched for age and sex. For all subjects rhinoscopy was done, skin prick test, nasal culture for S.aureus, nasal interleukin 4,nasal total IgE, serum total IgE and serum specific IgE(SSIgE for HDM. Nasal S.aureus was detected in 16/20 patients (80% and 5/20 (25% in healthy subjects with highly significant statistical difference plt0.01. Correlation of nasal staph.aureus count and different systemic and local immune markers revealed highly significant positive correlation between nasal S.aureus count and serum total IgE (r = 0.78, plt0.01 and significant positive correlation with SSIgE (HDM (r = 0.53, plt0.05, nasal total IgE (r = 0.39, plt0.05 and nasal IL-4 (r = 0.55, plt0.05. Nasal staph.aureus actively modulated the immune reaction in persistent allergic rhinitis patients by promoting local IgE production, so we recommend early detection and treatment of S.aureus carriage in patients

  20. Real-time quantitative PCR of Staphylococcus aureus and application in restaurant meals.

    Science.gov (United States)

    Berrada, H; Soriano, J M; Mañes, J; Picó, Y

    2006-01-01

    Staphylococcus aureus is considered the second most common pathogen to cause outbreaks of food poisoning, exceeded only by Campylobacter. Consumption of foods containing this microorganism is often identified as the cause of illness. In this study, a rapid, reliable, and sensitive real-time quantitative PCR was developed and compared with conventional culture methods. Real-time quantitative PCR was carried out by purifying DNA extracts of S. aureus with a Staphylococcus sample preparation kit and quantifying it in the LightCycler system with hybridization probes. The assay was linear from a range of 10 to 10(6) S. aureus cells (r2 > 0.997). The PCR reaction presented an efficiency of >85%. Accuracy of the PCR-based assay, expressed as percent bias, was around 13%, and the precision, expressed as a percentage of the coefficient of variation, was 7 to 10%. Intraday and interday variability were studied at 10(2) CFU/g and was 12 and 14%, respectively. The proposed method was applied to the analysis of 77 samples of restaurant meals in Valencia (Spain). In 11.6% of samples S. aureus was detected by real-time quantitative PCR, as well as by the conventional microbiological method. An excellent correspondence between real-time quantitative PCR and microbiological numbers (CFU/g) was observed with deviations of < 28%.

  1. Pulsed-field gel electrophoresis typing of Staphylococcus aureus isolates

    Science.gov (United States)

    Pulsed-field gel electrophoresis (PFGE) is the most applied and effective genetic typing method for epidemiological studies and investigation of foodborne outbreaks caused by different pathogens, including Staphylococcus aureus. The technique relies on analysis of large DNA fragments generated by th...

  2. THE EVOLUTION OF NEW HOSPITAL STRAINS OF STAPHYLOCOCCUS AUREUS.

    Science.gov (United States)

    JEVONS, M P; PARKER, M T

    1964-05-01

    The emergence of new groups of strains of Staph. aureus as important causes of endemic hospital infection in Great Britain has been followed by the phage typing method. Experiments are reported which suggest the possible origin of one of them.

  3. Portación y caracterización de Staphylococcus aureus en manipuladores de alimentos Carriage and characterization of Staphylococcus aureus in food handlers

    Directory of Open Access Journals (Sweden)

    Graciela B Jordá

    2012-06-01

    Full Text Available Staphylococcus aureus es una causa de intoxicaciones alimentarias por su capacidad de producir enterotoxinas. Los manipuladores de alimentos que portan S. aureus productores de enterotoxinas pueden provocar intoxicaciones alimentarias. Se estudiaron muestras tomadas de fosas nasales de 88 manipuladores de alimentos en la provincia de Misiones. El 37,5 % de los individuos analizados eran portadores de S. aureus. Mediante técnicas de amplificación (PCR, se detectaron genes que codifican la producción de enterotoxinas en 13 de los 33 aislamientos obtenidos (39,4 % y en el 14,7 % de los manipuladores. De estos aislamientos, 10 portaban el gen sea y 3 el gen sec. El estudio de sensibilidad a los antibióticos mostró un 100 % de sensibilidad a teicoplanina, gentamiclna y rifampicina; 2 aislamientos fueron resistentes a clindamicina y a eritromicina y 4 resultaron resistentes a la meticilina. Estos resultados son un alerta e indicarían la necesidad de desarrollar medidas racionales para reducir el riesgo potencial de intoxicaciones alimentarias.Staphylococcus aureus causes food poisoning due to its ability to produce enterotoxins. Food handlers carrying enterotoxin-producing S. aureus can contaminate food, thus leading to food poisoning. Samples were obtained from 88 food handlers in the Province of Misiones, Argentina. S. aureus was isolated from nasal swaps and PCR amplification was performed for genes encoding staphylococcal enterotoxins. A total of 37.5 % food handlers were positive for S. aureus. Expression of enterotoxin genes was found in 13 of the 33 (39.4 % S. aureus isolates studied, accounting for 14.7 % of food handlers. Gene sea was detected in 10 isolates followed by gene sec in 3 isolates. All isolates were susceptible to teicoplanin, gentamicin and rifampicin. Four isolates were resistant to methicillin whereas 2 isolates were resistant to clindamycin and erythromycin. These results constitute a critical alert and indicate the need

  4. In vitro growth inhibition of mastitis causing bacteria by phenolics and metal chelators

    Energy Technology Data Exchange (ETDEWEB)

    Chew, B.P.; Tjoelker, L.W.; Tanaka, T.S.

    1985-11-01

    Antimicrobial activities of three phenolic compounds and four metal chelators were tested at 0, 250, 500, and 1000 ppm in vitro against four major mastitis-causing bacteria, Streptococcus agalactiae, Staphylococcus aureus, Klebsiella pnuemoniae, and Escherichia coli. Overall, butylated hydroxyanisole and tert-butylhydroquinone showed the greatest antimicrobial activity. These phenolics were bactericidal at 250 to 500 ppm against all four bacteria tested. The butylated hydroxytoluene was bactericidal against the gram-positive bacteria but was ineffective against the coliforms. At 250 ppm, disodium ethylenediaminetetraacetic acid was bactericidal against the gram-positive bacteria but much less effective against the gram-negatives. However, diethylene-triaminepentaacetic acid was more growth inhibitory than ethylenediaminetetraacetic acid against the gram-negative bacteria and especially against Escherichia coli. All other compounds were generally much less effective or ineffective against all four microorganisms. Therefore, butylated hydroxyanisole, butylated hydroxytoluene, tert-butylhydroquinone, ethylenediaminetetraacetic acid, and diethylenetriaminepentaacetic acid may have practical implications in the prevention or treatment of bovine mastitis.

  5. Comparison phenotypic and genotypic identification of Staphylococcus species isolated from bovine mastitis

    Directory of Open Access Journals (Sweden)

    Felipe Freitas Guimarães

    Full Text Available ABSTRACT: In addition to Staphylococcus aureus nowadays other coagulase-positive staphylococci (CoPS and coagulase-negative staphylococci (CoNS, earlier considered of minor importance, are now accepted as relevant pathogens for humans and animals. The involvement of these microorganisms in bovine mastitis etiology and the possibility their transmission through milk to humans justify the requirement of developing reliable methods for identification of the most frequent species among them. The purpose of this study was to compare the phenotypic techniques with the genotypic method carried out by sequencing of the rpoB gene in identification of several species of the genus Staphylococcus isolated from bovine mastitis. A total of 300 staphylococci isolates of bovine mastitis cases from several Brazilian dairy herds were studied by phenotypic and genotypic techniques, respectively: 150 CoPS and 150 CoNS strains. A total of 18 CoNS different species and 4 CoPS species were identified. Among the CoNS the following species were recognized: 48 (32% Staphylococcus warneri, 22(15% S. epidermidis, 20(13% S. hyicus, 10(7% S. xylosus, 7(5% S. haemolyticus, 6(4% S. simulans, 6(4% S. schleiferi subsp schleiferi, 6(4% S. hominis, 5(3% S. pasteuri, 4(2.7% S. cohnii, 3(2% S. saprophyticus subsp. saprophyticus 3(2% S. chromogenes 3(2% S. sciuri, 2(1% S. saccharolyticus, 2(1% S. lugdunensi, 1(0,7% S. auricularis, 1(70% S. saprophyticus subsp. bovis, 1(0.7% S. capitis. And among the 150 CoPS were identified respectively: 105 (70% S. aureus, 21(14%, S. hyicus, 19(13% S. intermedius e 5(3% S. schleiferi subsp coagulans. Considering the 150 CoNS isolates, the identifications performed by phenotypic and genotypic tests presented 96.7% of concordance, kappa coefficient of agreement = 0.933, SE (standard error of kappa=0.021 (95% confidence interval: 0.893 to 0.974, Pearson’s correlation coefficient (r = 0.9977, (confidence interval 95%: 0.9938 a 0.9992 and in relation

  6. PCR detection of staphylococcal enterotoxin genes in Staphylococcus aureus strains isolated from raw and pasteurized milk.

    Science.gov (United States)

    Rall, V L M; Vieira, F P; Rall, R; Vieitis, R L; Fernandes, A; Candeias, J M G; Cardoso, K F G; Araújo, J P

    2008-12-10

    Milk is considered a nutritious food because it contains several important nutrients including proteins and vitamins. Conversely, it can be a vehicle for several pathogenic bacteria such as Staphylococcus aureus. This study aimed to analyze the frequency of genes encoding the staphylococcal enterotoxins (SEs) SEA, SEB, SEC, SED, SEE, SEG, SEH, SEI and SEJ in S. aureus strains isolated from raw or pasteurized bovine milk. S. aureus was found in 38 (70.4%) out of 54 raw milk samples at concentrations of up to 8.9 x 10(5) CFU/ml. This microorganism was present in eight samples of pasteurized milk before the expiration date and in 11 samples analyzed on the expiration date. Of the 57 strains studied, 68.4% were positive for one or more genes encoding the enterotoxins, and 12 different genotypes were identified. The gene coding for enterotoxin A, sea, was the most frequent (16 strains, 41%), followed by sec (8 strains, 20.5%), sed (5 strains, 12.8%), seb (3 strains, 7.7%) and see (2 strains, 5.1%). Among the genes encoding the other enterotoxins, seg was the most frequently observed (11 strains, 28.2%), followed by sei (10 strains) and seh and sej (3 strains each). With the recent identification of new SEs, the perceived frequency of enterotoxigenic strains has increased, suggesting that the pathogenic potential of staphylococci may be higher than previously thought; however, further studies are required to assess the expression of these new SEs by S. aureus, and their impact in foodborne disease. The quality of Brazilian milk is still low, and efforts from the government and the entire productive chain are required to attain consumer safety.

  7. Development of the immune response in pneumonia due to Staphylococcus aureus (part 2

    Directory of Open Access Journals (Sweden)

    A.E. Abaturov

    2017-04-01

    Full Text Available The article analyzes the role of pattern-recognition receptors involved in recognition of pathogen-associated molecular patterns of Staphylococcus aureus. There are shown the basic operation of macrophage and monocyte NLRP3, NLRC5, NLRP7, AIM2 inflammasomes that form the active forms of pro-inflammatory cytokines IL-1-beta and IL-18 du-ring the development of pneumonia caused by Staphylococcus aureus.

  8. Methicilin-resistant Staphylococcus aureus (MRSA) at Jos University ...

    African Journals Online (AJOL)

    A prospective surveillance of Methicillin resistant staphylococcus aureus (MRSA) was carried out at Jos University Teaching Hospital, Nigeria, over a one year period. This study highlights the continuos importance of MRSA in causing both hospital and to a less extent community acquired infections. Out of the 180 ...

  9. spa typing and antimicrobial resistance of Staphylococcus aureus from healthy humans, pigs and dogs in Tanzania

    DEFF Research Database (Denmark)

    Katakweba, Abdul S.; Muhairwa, Amandus P.; Espinosa-Gongora, Carmen

    2016-01-01

    . aureus carrier frequencies in dogs and humans were within the expected range and low in pigs. The S. aureus spa types circulating in the community were generally not shared by different hosts and majority of types belonged to known clones. Besides ampicillin resistance, moderate levels of antimicrobial......Introduction: Staphylococcus aureus is an opportunistic pathogen causing infections in humans and animals. Here we report for the first time the prevalence of nasal carriage, spa typing and antimicrobial resistance of S. aureus in a Tanzanian livestock community. Methodology: Nasal swabs were taken...... from 100 humans, 100 pigs and 100 dogs in Morogoro Municipal. Each swab was enriched in Mueller Hinton broth with 6.5% NaCl and subcultured on chromogenic agar for S. aureus detection. Presumptive S. aureus colonies were confirmed to the species level by nuc PCR and analysed by spa typing...

  10. Community-Associated Methicillin-Resistant Staphylococcus aureus Case Studies

    Science.gov (United States)

    Sowash, Madeleine G.; Uhlemann, Anne-Catrin

    2014-01-01

    Over the past decade, the emergence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has changed the landscape of S. aureus infections around the globe. Initially recognized for its ability to cause disease in young and healthy individuals without healthcare exposures as well as for its distinct genotype and phenotype, this original description no longer fully encompasses the diversity of CA-MRSA as it continues to expand its niche. Using four case studies, we highlight a wide range of the clinical presentations and challenges of CA-MRSA. Based on these cases we further explore the globally polygenetic background of CA-MRSA with a special emphasis on generally less characterized populations. PMID:24085688

  11. CHRONIC OSTEOMYELITIS: A BACTERIOLOGICAL STUDY WITH SPECIAL REFERENCE TO STAPHYLOCOCCUS AUREUS

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    Sanjoy Chakravarty

    2015-01-01

    Full Text Available Advances in the identification of infections and early diagnosis of Osteomyelitis have led to the improved management of Osteomyelitis. This study was undertaken to determine the bacteriological profile of Osteomyelitis and the antibiotic resistance pattern of various isolates obtained as it is an important cause of morbidity. A total of 50 patients of Osteomyelitis either attending the outpatient department or admitted in the wards of a teaching and tertiary care hospita l in Sikkim from October 2013 to October, 2014 were included in the study. All those patients who were clinically and/ or radiologically suspected of having Osteomyelitis were enrolled as cases. Pus/ pus swabs or sequestrum samples taken aseptically were c ultured aerobically at 37 0 C for 18 - 24 hours in Blood and Mac Conkey agar plates. Culture isolates were identified by a series of standard biochemical reactions. Antibiotic susceptibility was tested on Mueller Hinton agar by Kirby Bauer disc diffusion met hod. Betalactamase production of S. aureus strains were verified by iodometric filter paper and acidometric agar plate methods. S. aureus strains were screened for methicillin resistance by using conventional microbiological methods. S. aureus turned out t o be the most common organism isolated. Other organism isolated were P. Aeruginosa, Proteus spp., Klebsiella spp., E. coli, Enterobacter spp., S. epidermitis, Streptococcus pyogens and Enterococcus spp. Beta - lactamase production and methicillin resistance was seen in S. aureus strains respectively. Multidrug resistance was observed in other strains. Infection caused by Methicillin resistant S. aureus and multidrug resistant organisms are posing a major challenge in the treatment of Osteomyelitis. So, appropriate drug selected by antibiotic sensitivity testing should be used to treat Osteomyelitis

  12. Improving Diagnosis and Treatment of Staphylococcus aureus Infections : Experimental Studies

    NARCIS (Netherlands)

    S. van den Berg (Sanne)

    2015-01-01

    markdownabstract__Abstract__ Staphylococcus aureus is an opportunistic pathogen that causes a variety of infections, ranging from mild skin infections like furuncles and impetigo, to severe, lifethreatening infections including endocarditis, osteomyelitis and pneumonia. Invasive infections are

  13. The rise of methicillin resistant Staphylococcus aureus: now the dominant cause of skin and soft tissue infection in Central Australia.

    Science.gov (United States)

    Macmorran, E; Harch, S; Athan, E; Lane, S; Tong, S; Crawford, L; Krishnaswamy, S; Hewagama, S

    2017-10-01

    This study aimed to examine the epidemiology and treatment outcomes of community-onset purulent staphylococcal skin and soft tissue infections (SSTI) in Central Australia. We performed a prospective observational study of patients hospitalised with community-onset purulent staphylococcal SSTI (n = 160). Indigenous patients accounted for 78% of cases. Patients were predominantly young adults; however, there were high rates of co-morbid disease. Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) was the dominant phenotype, accounting for 60% of cases. Hospitalisation during the preceding 6 months, and haemodialysis dependence were significant predictors of CA-MRSA infection on univariate analysis. Clinical presentation and treatment outcomes were found to be comparable for methicillin-susceptible S. aureus (MSSA) and methicillin-resistant cases. All MRSA isolates were characterised as non-multi-resistant, with this term used interchangeably with CA-MRSA in this analysis. We did not find an association between receipt of an active antimicrobial agent within the first 48 h, and progression of infection; need for further surgical debridement; unplanned General Practitioner or hospital re-presentation; or need for further antibiotics. At least one adverse outcome was experienced by 39% of patients. Clindamycin resistance was common, while rates of trimethoprim-sulfamethoxazole resistance were low. This study suggested the possibility of healthcare-associated transmission of CA-MRSA. This is the first Australian report of CA-MRSA superseding MSSA as the cause of community onset staphylococcal SSTI.

  14. Antibody Tracing, Seroepidemiology and Risk Factors of Bovine Respiratory Syncytial Virus and Bovine Adenovirus-3 in Dairy Holstein Farms

    Directory of Open Access Journals (Sweden)

    Mahsa FARZINPOUR

    2016-01-01

    Full Text Available Antibody tracing, risk factors and seroepidemiology of bovine respiratory syncytial virus and bovine adenovirus-3 were investigated in 22 Industrial and Semi-Industrial dairy Holstein farms. Serum samples (n=736 from various ages of unvaccinated cows were collected from May to September 2012. Risk factors including age, past history of respiratory diseases, amount of milk production, husbandry type and herd size were considered. Data were analyzed by Chi-square and logistic regression. Results indicated that the infection with some of individual viruses was related to past history of respiratory disease and herd size. No specific pattern was seen on the effect of level of milk production on seropositivity of animals. The seroprevalence for BRSV and BAV-3 were 89.1% and 88%, respectively. The present study indicates that infections of bovine respiratory viruses frequently occur in cattle of Fars province and the main viral cause of primary occurrence of respiratory diseases may be due to aforementioned viruses.

  15. Risk factors assessment for nasal colonization of Staphylococcus aureus and its methicillin resistant strains among pre-clinical medical students of Nepal.

    Science.gov (United States)

    Ansari, Shamshul; Gautam, Rajendra; Shrestha, Sony; Ansari, Safiur Rahman; Subedi, Shankar Nanda; Chhetri, Muni Raj

    2016-04-12

    Staphylococcus aureus (S. aureus), a normal flora of nasal cavity, can cause minor to life threatening invasive diseases and nosocomial infections. Methicillin resistant strains of S. aureus are causing a great challenge for treatment options. Therefore, the purpose of this study was to assess the nasal carriage rate of S. aureus, its methicillin resistant strains and risk factors in medical students prior to clinical exposure. The bacterial growth of S. aureus from nasal swab culture was identified by using standard microbiological methods recommended by American Society for Microbiology. Modified Kirby-Bauer disk diffusion method was used for antibiotic susceptibility testing and methicillin resistance was confirmed using cefoxitin and oxacillin disks. D-zone test method was used to determine the inducible clindamycin resistance. Among 200 participants, nasal carriage of S. aureus was detected from 30 (15%) subjects. Upper respiratory tract infections significantly (P aureus and their methicillin resistant strains. All of the isolates were reported to be susceptible to vancomycin and teicoplanin. S. aureus strains detected from 8 (4%) students were confirmed to be methicillin resistant. The result of our study demands for strict policy to screen all the students for nasal carriage of S. aureus and its MRSA strains to minimize the transmission of this organism from community to hospital settings.

  16. Identification of pathogenic factors potentially involved in Staphylococcus aureus keratitis using proteomics.

    Science.gov (United States)

    Khan, Shamila; Cole, Nerida; Hume, Emma B H; Garthwaite, Linda L; Nguyen-Khuong, Terry; Walsh, Bradley J; Willcox, Mark D P

    2016-10-01

    Staphylococcus is a leading cause of microbial keratitis, characterized by destruction of the cornea by bacterial exoproteins and host-associated factors. The aim of this study was to compare extracellular and cell-associated proteins produced by two different isolates of S. aureus, a virulent clinical isolate (Staph 38) and a laboratory strain (Staphylococcus aureus 8325-4) of weaker virulence in the mouse keratitis model. Proteins were analyzed using 2D polyacrylamide gel electrophoresis and identified by subsequent mass spectrometry. Activity of staphylococcal adhesins was assessed by allowing strains to bind to various proteins adsorbed onto polymethylmethacrylate squares. Thirteen proteins in the extracellular fraction and eight proteins in the cell-associated fractions after bacterial growth were produced in increased amounts in the clinical isolate Staph 38. Four of these proteins were S. aureus virulence factor adhesins, fibronectin binding protein A, staphopain, glyceraldehyde-3-phosphate dehydrogenase 2 and extracellular adherence protein. The clinical isolate Staph 38 adhered to a greater extent to all mammalian proteins tested, indicating the potential of the adhesins to be active on its surface. Other proteins with increased expression in Staph 38 included potential moonlighting proteins and proteins involved in transcription or translation. This is the first demonstration of the proteome of S. aureus isolates from keratitis. These results indicate that the virulent clinical isolate produces more potentially important virulence factors compared to the less virulent laboratory strain and these may be associated with the ability of a S. aureus strain to cause more severe keratitis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Secreted Immunomodulatory Proteins of Staphylococcus aureus Activate Platelets and Induce Platelet Aggregation.

    Science.gov (United States)

    Binsker, Ulrike; Palankar, Raghavendra; Wesche, Jan; Kohler, Thomas P; Prucha, Josephine; Burchhardt, Gerhard; Rohde, Manfred; Schmidt, Frank; Bröker, Barbara M; Mamat, Uwe; Pané-Farré, Jan; Graf, Anica; Ebner, Patrick; Greinacher, Andreas; Hammerschmidt, Sven

    2018-04-01

    Staphylococcus aureus can cause bloodstream infections associated with infective endocarditis (IE) and disseminated intravascular coagulopathy (DIC). Both complications involve platelets. In view of an increasing number of antibiotic-resistant strains, new approaches to control systemic S. aureus infection are gaining importance. Using a repertoire of 52 recombinant S. aureus proteins in flow cytometry-based platelet activation and aggregation assays, we identified, in addition to the extracellular adherence protein Eap, three secreted staphylococcal proteins as novel platelet activating proteins. Eap and the chemotaxis inhibitory protein of S. aureus (CHIPS), the formyl peptide receptor-like 1 inhibitory protein (FLIPr) and the major autolysin Atl induced P-selectin expression in washed platelets and platelet-rich plasma. Similarly, AtlA, CHIPS and Eap induced platelet aggregation in whole blood. Fluorescence microscopy illustrated that P-selectin expression is associated with calcium mobilization and re-organization of the platelet actin cytoskeleton. Characterization of the functionally active domains of the major autolysin AtlA and Eap indicates that the amidase domain of Atl and the tandem repeats 3 and 4 of Eap are crucial for platelet activation. These results provide new insights in S. aureus protein interactions with platelets and identify secreted proteins as potential treatment targets in case of antibiotic-resistant S. aureus infection. Schattauer GmbH Stuttgart.

  18. Regulation of Expression of Oxacillin-Inducible Methionine Sulfoxide Reductases in Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Kyle R. Baum

    2015-01-01

    Full Text Available Cell wall-active antibiotics cause induction of a locus that leads to elevated synthesis of two methionine sulfoxide reductases (MsrA1 and MsrB in Staphylococcus aureus. To understand the regulation of this locus, reporter strains were constructed by integrating a DNA fragment consisting of the msrA1/msrB promoter in front of a promoterless lacZ gene in the chromosome of wild-type and MsrA1-, MsrB-, MsrA1/MsrB-, and SigB-deficient methicillin-sensitive S. aureus strain SH1000 and methicillin-resistant S. aureus strain COL. These reporter strains were cultured in TSB and the cellular levels of β-galactosidase activity in these cultures were assayed during different growth phases. β-galactosidase activity assays demonstrated that the lack of MsrA1, MsrB, and SigB upregulated the msrA1/msrB promoter in S. aureus strain SH1000. In S. aureus strain COL, the highest level of β-galactosidase activity was observed under the conditions when both MsrA1 and MsrB proteins were absent. The data suggest that the msrA1/msrB locus, in part, is negatively regulated by MsrA1, MsrB, and SigB in S. aureus.

  19. Identification of Host Defense-Related Proteins Using Label-Free Quantitative Proteomic Analysis of Milk Whey from Cows with Staphylococcus aureus Subclinical Mastitis

    Directory of Open Access Journals (Sweden)

    Shaimaa Abdelmegid

    2017-12-01

    Full Text Available Staphylococcus aureus is the most common contagious pathogen associated with bovine subclinical mastitis. Current diagnosis of S. aureus mastitis is based on bacteriological culture of milk samples and somatic cell counts, which lack either sensitivity or specificity. Identification of milk proteins that contribute to host defense and their variable responses to pathogenic stimuli would enable the characterization of putative biomarkers of subclinical mastitis. To accomplish this, milk whey samples from healthy and mastitic dairy cows were analyzed using a label-free quantitative proteomics approach. In total, 90 proteins were identified, of which 25 showed significant differential abundance between healthy and mastitic samples. In silico functional analyses indicated the involvement of the differentially abundant proteins in biological mechanisms and signaling pathways related to host defense including pathogen-recognition, direct antimicrobial function, and the acute-phase response. This proteomics and bioinformatics analysis not only facilitates the identification of putative biomarkers of S. aureus subclinical mastitis but also recapitulates previous findings demonstrating the abundance of host defense proteins in intramammary infection. All mass spectrometry data are available via ProteomeXchange with identifier PXD007516.

  20. Bovine cysticercosis situation in Brazil

    Directory of Open Access Journals (Sweden)

    Gabriel Augusto Marques Rossi

    2014-02-01

    Full Text Available The taeniasis-cysticercosis complex is a long known zoonotic parasitosis characteristic of underdeveloped countries. In addition to its public health significance, this parasitosis is cause of economic losses to the beef production chain, and synonymous of technical inadequacy in relation to the adoption of Good Agricultural Practices. The occurrences of both human teniasis and bovine cysticercosis could and should be controlled with basic sanitary measures. However, there is much variation in the occurrence of the disease in cattle, characterizing a low rate of technical development as well as problems related to the adoption of basic sanitation measures. This review describes, in details, the causative agent and its epidemiological chain, besides raising current information about the occurrence of bovine cysticercosis in different regions of Brazil, aiming at the adoption of prophylactic measures by different segments responsible.

  1. Staphylococcus aureus induces IL-8 expression through its lipoproteins in the human intestinal epithelial cell, Caco-2.

    Science.gov (United States)

    Kang, Seok-Seong; Noh, Su Young; Park, Ok-Jin; Yun, Cheol-Heui; Han, Seung Hyun

    2015-09-01

    Staphylococcus aureus can cause the intestinal inflammatory diseases. However, little is known about the molecular mechanism of S. aureus infection in the intestine. In the present study, we investigated whether S. aureus could stimulate human intestinal epithelial cells triggering inflammation. When the human intestinal epithelial cell-line, Caco-2, and the primary colon cells were stimulated with ethanol-inactivated S. aureus, IL-8 expression was induced in a dose-dependent manner. The inactivated S. aureus preferentially stimulated Toll-like receptor (TLR) 2 rather than TLR4. Lipoproteins, lipoteichoic acid (LTA), and peptidoglycan (PGN) are considered as potential TLR2 ligands of S. aureus. Interestingly, S aureus lipoproteins and Pam2CSK4 mimicking Gram-positive bacterial lipoproteins, but not LTA and PGN of S. aureus, significantly induced IL-8 expression in Caco-2 cells. Furthermore, lipoprotein-deficient S. aureus mutant strain failed to induce IL-8 production. Collectively, these results suggest that S. aureus stimulates the human intestinal epithelial cells to induce the chemokine IL-8 production through its lipoproteins, potentially contributing the development of intestinal inflammation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Prevalence of Staphylococcus aureus colonization in renal transplant patients

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Ribeiro Lamblet

    2014-10-01

    Full Text Available Objective to evaluate the prevalence of Staphylococcus aureus nasal colonization in renal transplant patients and to identify the related risk factors. Method Swabs were used to collect nasal samples from 160 patients who had undergone a transplant within the previous year at the Kidney and Hypertension Hospital. The ‘National Committee for Clinical Laboratory Standards’ norms were followed for the collection, isolation, identification and sensitivity measurements. Results There was a 9.4% (15 prevalence of Staphylococcus aureus nasal colonization, of which one (6.7% was resistant to oxacillin. It was possible to identify as an associated risk factor a wait of more than one year for accessing dialysis prior to the transplant (p=0.029. Conclusion Given the high morbidity and mortality rates that this microorganism causes in the target population, other studies should be carried out, and pre- and post-transplant screening should occur in order to develop strategies that improve the prevention and control of the spread of Staphylococcus aureus.

  3. Cow-to-cow variation in fibroblast response to a toll-like receptor 2/6 agonist and its relation to mastitis caused by intramammary challenge with Staphylococcus aureus.

    Science.gov (United States)

    Benjamin, A L; Green, B B; Hayden, L R; Barlow, J W; Kerr, D E

    2015-03-01

    Staphylococcus aureus is a common cause of chronic mammary gland infections in dairy cattle. However, the inflammatory response and duration of infection following pathogen exposure is variable between individual animals. To investigate interanimal differences in immune response, dermal fibroblast cultures were established from skin biopsies collected from 50 early lactation Holstein cows. The fibroblasts ability to produce IL-8 in response to a 24-h treatment with a synthetic toll-like receptor 2/6 agonist (Pam2CSK4) was used to assign a response phenotype to the animals. Five high-responding and 5 low-responding animals were then selected for an intramammary challenge with S. aureus to evaluate differences in the inflammatory response, chronicity of infection, and development of antibodies to the pathogen. All animals exhibited clinical symptoms of mastitis at 24h postchallenge. Animals previously classified as high responders experienced a greater inflammatory response characterized by elevated levels of milk somatic cell count, IL-8, and BSA following the challenge compared with low responders. In addition, antibodies toward the challenge strain of S. aureus reached higher levels in whey from the challenged gland of high responders compared with low responders. Despite the antibody response, all 5 high responders were chronically infected for the 6-wk duration of the study, whereas 2 of the low responders cleared the infection, although 1 of these did become reinfected. The observed differences between animals classified as low and high responders based on their fibroblast responsiveness suggests that this cell type can be used to further examine the causes of interanimal variation in response to mammary infection. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  4. Prevalence of toxin genes among the clinical isolates of Staphylococcus aureus and its clinical impact

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    Divya Deodhar

    2015-01-01

    Full Text Available Introduction: Staphylococcus aureus (S. aureus causes a variety of infections, ranging from a mild skin infection to blood stream infections and deep seated infections. As Stapylococcus aureus bacteremia (SAB has the tendency to cause endovascular and metastatic infections, complications can occur at almost all sites of the body. Hence, SAB is associated with increased morbidity and mortality in spite of appropriate antimicrobial treatment. The virulence in S. aureus is determined by the presence of adhesins and toxins, which behave like superantigens (SAgs and leads to a massive release of proinflammatory cytokines causing overwhelming inflammatory response leading to endothelial leakage, hemodynamic shock, multiorgan failure, and possibly death. Materials and Methods: One year prospective study conducted in a tertiary care hospital in southern part of India included all patients with SAB. Clinical details were filled according to. All isolates were subjected to polymerase chain reaction (PCR for enterotoxin profiling. Results: A total of 101 patients of SAB were identified which comprises of 61 (60.4% patients with methicillin-susceptible S. aureus (MSSA and 40 (39.6% patients with methicillin-resistant S. aureus (MRSA. Most common predictors of mortality were prior hospitalization and antibiotic intake, severe organ dysfunction, shock, tachycardia, and leukocytosis. Two-third of the isolates had at least one enterotoxin, most prevalent was sea; 28% and 27% (P - value = 0.001 MSSA isolates had seg and sei; whereas, 38.6% (P - value < 0.001 of MRSA isolates were found to have sea. The most common enterotoxin associated with mortality was sei, which comprised of 38% of all mortality. Conclusion: In SAB, the significant predictors of mortality were prior hospitalization and antibiotic intake, presence of multiorgan dysfunction, and shock. Although overall significance between the enterotoxin and shock could not be demonstrated, it successfully

  5. Prevalence of Toxin Genes among the Clinical Isolates of Staphylococcus aureus and its Clinical Impact.

    Science.gov (United States)

    Deodhar, Divya; Varghese, George; Balaji, Veeraraghavan; John, James; Rebekah, Grace; Janardhanan, Jeshina; Jeyaraman, Ranjith; Jasmine, Sudha; Mathews, Prasad

    2015-01-01

    Staphylococcus aureus (S. aureus) causes a variety of infections, ranging from a mild skin infection to blood stream infections and deep seated infections. As Stapylococcus aureus bacteremia (SAB) has the tendency to cause endovascular and metastatic infections, complications can occur at almost all sites of the body. Hence, SAB is associated with increased morbidity and mortality in spite of appropriate antimicrobial treatment. The virulence in S. aureus is determined by the presence of adhesins and toxins, which behave like superantigens (SAgs) and leads to a massive release of proinflammatory cytokines causing overwhelming inflammatory response leading to endothelial leakage, hemodynamic shock, multiorgan failure, and possibly death. One year prospective study conducted in a tertiary care hospital in southern part of India included all patients with SAB. Clinical details were filled according to. All isolates were subjected to polymerase chain reaction (PCR) for enterotoxin profiling. A total of 101 patients of SAB were identified which comprises of 61 (60.4%) patients with methicillin-susceptible S. aureus (MSSA) and 40 (39.6%) patients with methicillin-resistant S. aureus (MRSA). Most common predictors of mortality were prior hospitalization and antibiotic intake, severe organ dysfunction, shock, tachycardia, and leukocytosis. Two-third of the isolates had at least one enterotoxin, most prevalent was sea; 28% and 27% (P - value = 0.001) MSSA isolates had seg and sei; whereas, 38.6% (P - value < 0.001) of MRSA isolates were found to have sea. The most common enterotoxin associated with mortality was sei, which comprised of 38% of all mortality. In SAB, the significant predictors of mortality were prior hospitalization and antibiotic intake, presence of multiorgan dysfunction, and shock. Although overall significance between the enterotoxin and shock could not be demonstrated, it successfully demonstrated the difference of enterotoxin between MSSA and MRSA.

  6. A review on bovine besnoitiosis: a disease with economic impact in herd health management, caused by Besnoitia besnoiti (Franco and Borges, ).

    Science.gov (United States)

    Cortes, Helder; Leitão, Alexandre; Gottstein, Bruno; Hemphill, Andrew

    2014-09-01

    Bovine besnoitiosis is caused by the largely unexplored apicomplexan parasite Besnoitia besnoiti. In cows, infection during pregnancy often results in abortion, and chronically infected bulls become infertile. Similar to other apicomplexans B. besnoiti has acquired a largely intracellular lifestyle, but its complete life cycle is still unknown, modes of transmission have not been entirely resolved and the definitive host has not been identified. Outbreaks of bovine besnoitiosis in cattle were described in the 1990s in Portugal and Spain, and later several cases were also detected in France. More cases have been reported recently in hitherto unaffected countries, including Italy, Germany, Switzerland, Hungary and Croatia. To date, there is still no effective pharmaceutical compound available for the treatment of besnoitiosis in cattle, and progress in the identification of novel targets for intervention through pharmacological or immunological means is hampered by the lack of molecular data on the genomic and transcriptomic level. In addition, the lack of an appropriate small animal laboratory model, and wide gaps in our knowledge on the host-parasite interplay during the life cycle of this parasite, renders vaccine and drug development a cost- and labour-intensive undertaking.

  7. Changing epidemiology of the tick-borne bovine parasite, Babesia divergens

    OpenAIRE

    Zintl, A; McGrath, G; O'Grady, L; Fanning, J; Downing, K; Roche, D; Casey, M; Gray, JS

    2014-01-01

    Bovine babesiosis is caused by the tick-borne blood parasite, Babesia divergens. A survey of veterinary practitioners and farmers in Ireland in the 1980’s revealed an annual incidence of 1.7% associated with considerable economic losses. However, two subsequent surveys in the 1990’s indicated a decline in clinical babesiosis. In order to determine whether any such changes have affected the incidence of bovine babesiosis in Ireland, a questionnaire survey of farmers and veterinarians was carri...

  8. Effects of Fermented Sumach on the Formation of Slime Layer of Staphylococcus aureus

    OpenAIRE

    Kırmusaoğlu, Sahra; Yurdugül, Seyhun; Koçoğlu, Esra

    2012-01-01

    Objective: Staphylococcus aureus (S. aureus) is one of the most commonly isolated bacterial pathogens in hospitals, and the most frequent cause of nosocomial infections. Nosocomial staphylococcal foreign-body infections related to biofilm formation are a serious threat, demanding new therapeutic and preventive strategies. Implantation of intravenous catheters and surgical implantation of prosthetic implants carry a risk of infection. In order to prevent all these effects of biofilms, a study ...

  9. Concentração mínima inibitória de dez antimicrobianos para amostras de Staphylococcus aureus isoladas de infecção intramamária bovina Minimum inhibitory concentrations for ten antimicrobial agents against Staphylococcus aureus from bovine intramammary infection

    Directory of Open Access Journals (Sweden)

    M.A.V.P. Brito

    2001-10-01

    Full Text Available Determinou-se a concentração mínima inibitória (CMI de ampicilina, cefalotina, eritromicina, gentamicina, neomicina, norfloxacina, oxacilina, penicilina G, tetraciclina e tilosina para 112 amostras de Staphylococcus aureus isoladas de infecções intramamárias bovina, em 33 rebanhos leiteiros da Zona da Mata do Estado de Minas Gerais. Foram isoladas 24 amostras de infecção clínica, 66 de subclínica e 22 de infecção crônica. As amostras de infecção crônica foram isoladas repetidas vezes dos mesmos quartos mamários de nove vacas de um rebanho, no período de 13 meses. A CMI foi realizada em ágar Mueller Hinton, com concentrações entre 0,015 e 128µgml-1 de cada antimicrobiano. As amostras da American Type Culture Collection (ATCC recomendadas para controle de qualidade, S. aureus ATCC 29213, Escherichia coli ATCC 25922 e Pseudomonas aeruginosa ATCC 27853, foram incluídas em cada teste. Cem por cento das amostras foram susceptíveis à cefalotina, eritromicina, gentamicina, norfloxacina e oxacilina, 91% à tetraciclina (CMI50: 0,5µgml-1 e à tilosina (CMI50: 2,0µgml-1, 65% à ampicilina (CMI50: 0,125µgml-1 e à penicilina G (CMI50: 0,06µgml-1. Todas foram susceptíveis à neomicina (CMI50: 0,5µgml-1 exceto uma amostra que apresentou um padrão intermediário. O nível de resistência para ampicilina e penicilina foi maior nas amostras isoladas de casos clínicos e nas de infecção subclínica com escores positivos no CMT (P ou = 0,125µgml-1 para penicilina foram positivas para produção de beta-lactamase.The minimum inhibitory concentrations (MIC for ampicillin, cephalothin, erythromycin, gentamicin, neomycin, norfloxacin, oxacillin, penicillin G, tetracycline and tylosin against 112 Staphylococcus aureus strains isolated from bovine intramammary infections were determined. The strains were originated from 33 dairy herds located in the Zona da Mata, Minas Gerais State. Twenty-four strains were isolated from clinical

  10. Dose Assessment of Cefquinome by Pharmacokinetic/Pharmacodynamic Modeling in Mouse Model of Staphylococcus aureus Mastitis

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    Yang Yu

    2016-10-01

    Full Text Available This work aimed to characterize the mammary gland pharmacokinetics of cefquinome after an intramammary administration and integrate pharmacokinetic/pharmacodynamic model. The pharmacokinetic profiles of cefquinome in gland tissue were measured using high performance liquid chromatograph. Therapeutic regimens covered various dosages ranging from 25 to 800 μg/gland and multiple dosing intervals of 8, 12, and 24 h. The in vivo bacterial killing activity elevated when dosage increased or when dosing intervals were shortened. The best antibacterial effect was demonstrated by a mean 1.5 log10CFU/gland visible count reduction. On the other hand, the results showed that the percentage of time duration of drug concentration exceeding the MIC during a dose interval (%T > MIC was generally 100% because of the influence of drug distribution caused by the blood-milk barrier. Therefore, pharmacokinetic/pharmacodynamic parameter of the ratio of area under the concentration-time curve over 24 h to the MIC (AUC0-24/MIC was used to describe the efficacy of cefquinome instead of %T > MIC. When the magnitude of AUC0-24/MIC exceeding 16571.55 h•mL/g, considerable activity of about 1.5 log10CFU/g gland bacterial count reduction was observed in vivo. Based on the Monte Carlo simulation, the clinical recommended regimen of three infusions of 75 mg per quarter every 12 h can achieve a 76.67% cure rate in clinical treatment of bovine mastitis caused by Staphylococcus aureus infection.

  11. Molecular detection of Staphylococcus aureus resistant to temperature in milk and its products

    Science.gov (United States)

    Sutejo, Stephani Valentina Harda; Amarantini, Charis; Budiarso, Tri Yahya

    2017-11-01

    Contamination of Staphylococcus aureus on milk can cause intoxication and infection by Staphylococcal enterotoxin. It has nuc gene, coding thermonuclease enzyme (TNase) that is responsible for nature of resistance in the heating process. This study was conducted to identify nuc gene of as S. aureus isolated from milk and its products like ultra-high temperature, sterile milk, sweetened condensed milk, formula milk, café/milk street traders and fresh milk. Biochemical identification was conducted by using carbohydrate fermentation tests and confirmed by API Staph. Molecular confirmation by amplification of nuc gene using PCR. Based on the results of confirmation using API Staph, all isolates were confirmed as S. aureus with index determinant percentage of 97%. An amplicon product of 270 bp was gained in all isolates. It is concluded that isolate of S. aureus has nuc gene.

  12. Staphylococcus aureus bacteriuria as a prognosticator for outcome of Staphylococcus aureus bacteremia: a case-control study

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    Weinstein Robert A

    2010-07-01

    Full Text Available Abstract Background When Staphylococcus aureus is isolated in urine, it is thought to usually represent hematogenous spread. Because such spread might have special clinical significance, we evaluated predictors and outcomes of S. aureus bacteriuria among patients with S. aureus bacteremia. Methods A case-control study was performed at John H. Stroger Jr. Hospital of Cook County among adult inpatients during January 2002-December 2006. Cases and controls had positive and negative urine cultures, respectively, for S. aureus, within 72 hours of positive blood culture for S. aureus. Controls were sampled randomly in a 1:4 ratio. Univariate and multivariable logistic regression analyses were done. Results Overall, 59% of patients were African-American, 12% died, 56% of infections had community-onset infections, and 58% were infected with methicillin-susceptible S. aureus (MSSA. Among 61 cases and 247 controls, predictors of S. aureus bacteriuria on multivariate analysis were urological surgery (OR = 3.4, p = 0.06 and genitourinary infection (OR = 9.2, p = 0.002. Among patients who died, there were significantly more patients with bacteriuria than among patients who survived (39% vs. 17%; p = 0.002. In multiple Cox regression analysis, death risks in bacteremic patients were bacteriuria (hazard ratio 2.9, CI 1.4-5.9, p = 0.004, bladder catheter use (2.0, 1.0-4.0, p = 0.06, and Charlson score (1.1, 1.1-1.3, p = 0.02. Neither length of stay nor methicillin-resistant Staphylococcus aureus (MRSA infection was a predictor of S. aureus bacteriuria or death. Conclusions Among patients with S. aureus bacteremia, those with S. aureus bacteriuria had 3-fold higher mortality than those without bacteriuria, even after adjustment for comorbidities. Bacteriuria may identify patients with more severe bacteremia, who are at risk of worse outcomes.

  13. Seroprevalence of bovine theileriosis in northern China

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    Yaqiong Li

    2016-11-01

    Full Text Available Abstract Background Bovine theileriosis is a common disease transmitted by ticks, and can cause loss of beef and dairy cattle worldwide. Here, an indirect enzyme-linked immunosorbent assay (iELISA based on Theileria luwenshuni surface protein (TlSP was developed and used to carry out a seroepidemiological survey of bovine theileriosis in northern China. Methods We used the BugBuster Ni-NTA His•Bind Purification Kit to purify recombinant TlSP (rTlSP, which was subsequently analyzed by Western Blotting to evaluate cross-reactivity with other pathogen-positive sera. The iELISA method based on rTlSP was successfully developed. Sera from 2005 blood samples were tested with the rTlSP-iELISA method, and blood smears from these samples were observed by microscopy. Results The specificity of iELISA was 98.9%, the sensitivity was 98.5%, and the cut-off was selected as 24.6%. Western Blot analysis of rTlSP confirmed that there were cross-reactions with Theileria luwenshuni, Theileria uilenbergi, Theileria ovis, Theileria annulata, Theileria orientalis and Theileria sinensis. The epidemiological survey showed that the highest positive rate of bovine theileriosis was 98.3%, the lowest rate was 84.1%, and the average positive rate was 95.4% by iELISA. With microscopy, the highest positive rate was 38.9%, the lowest rate was 5.1%, and the relative average positive rate was 13.7%. Conclusions An rTlSP-iELISA was developed to detect circulating antibodies against bovine Theileria in northern China. This is the first report on the seroprevalence of bovine theileriosis in northern China, and it also provides seroepidemiological data on bovine theileriosis in China.

  14. Induction of type I interferon signaling determines the relative pathogenicity of Staphylococcus aureus strains.

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    Dane Parker

    2014-02-01

    Full Text Available The tremendous success of S. aureus as a human pathogen has been explained primarily by its array of virulence factors that enable the organism to evade host immunity. Perhaps equally important, but less well understood, is the importance of the intensity of the host response in determining the extent of pathology induced by S. aureus infection, particularly in the pathogenesis of pneumonia. We compared the pathogenesis of infection caused by two phylogenetically and epidemiologically distinct strains of S. aureus whose behavior in humans has been well characterized. Induction of the type I IFN cascade by strain 502A, due to a NOD2-IRF5 pathway, was the major factor in causing severe pneumonia and death in a murine model of pneumonia and was associated with autolysis and release of peptidogylcan. In contrast to USA300, 502A was readily eliminated from epithelial surfaces in vitro. Nonetheless, 502A caused significantly increased tissue damage due to the organisms that were able to invade systemically and trigger type I IFN responses, and this was ameliorated in Ifnar⁻/⁻ mice. The success of USA300 to cause invasive infection appears to depend upon its resistance to eradication from epithelial surfaces, but not production of specific toxins. Our studies illustrate the important and highly variable role of type I IFN signaling within a species and suggest that targeted immunomodulation of specific innate immune signaling cascades may be useful to prevent the excessive morbidity associated with S. aureus pneumonia.

  15. European ST80 community-associated methicillin-resistant Staphylococcus aureus orbital cellulitis in a neonate

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    Tsironi Evangelia E

    2012-05-01

    Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus is a serious cause of morbidity and mortality in hospital environment, but also, lately, in the community. This case report is, to our knowledge, the first detailed description of a community-associated methicillin-resistant S. aureus ST80 orbital cellulitis in a previously healthy neonate. Possible predisposing factors of microbial acquisition and treatment selection are also discussed. Case presentation A 28-day-old Caucasian boy was referred to our hospital with the diagnosis of right orbital cellulitis. His symptoms included right eye proptosis, periocular edema and redness. Empirical therapy of intravenous daptomycin, rifampin and ceftriaxone was initiated. The culture of pus yielded a methicillin-resistant S. aureus isolate and the molecular analysis revealed that it was a Panton-Valentine leukocidine-positive ST80 strain. The combination antimicrobial therapy was continued for 42days and the infection was successfully controlled. Conclusions Clinicians should be aware that young infants, even without any predisposing condition, are susceptible to orbital cellulitis caused by community-associated methicillin-resistant S. aureus. Prompt initiation of the appropriate empirical therapy, according to the local epidemiology, should successfully address the infection, preventing ocular and systemic complications.

  16. Accuracy of Clinicians in Predicting the Bacterial Cause of Clinical Bovine Mastitis

    OpenAIRE

    White, Maurice E.; Glickman, Lawrence T.; Barnes-Pallesen, Frances D.; Stem, Edgar S.; Dinsmore, Page; Powers, Michael S.; Powers, Pamela; Smith, Mary C.; Jasko, David

    1986-01-01

    We examined the ability of clinicians to predict the causative organism of bovine mastitis in our practice. We obtained 118 milk culture results from 112 mastitic cows and compared the culture results to the predictions of clinicians at the time of milk sample collection. Sixty of 118 culture results were accurately predicted. The positive predictive value for coliform mastitis was 42% and the negative predictive value was 79% in a study population with a 31% prevalence of coliform mastitis. ...

  17. Heme Recognition By a Staphylococcus Aureus IsdE

    Energy Technology Data Exchange (ETDEWEB)

    Grigg, J.C.; Vermeiren, C.L.; Heinrichs, D.E.; Murphy, M.E.P.

    2009-06-03

    Staphylococcus aureus is a Gram-positive bacterial pathogen and a leading cause of hospital acquired infections. Because the free iron concentration in the human body is too low to support growth, S. aureus must acquire iron from host sources. Heme iron is the most prevalent iron reservoir in the human body and a predominant source of iron for S. aureus. The iron-regulated surface determinant (Isd) system removes heme from host heme proteins and transfers it to IsdE, the cognate substrate-binding lipoprotein of an ATP-binding cassette transporter, for import and subsequent degradation. Herein, we report the crystal structure of the soluble portion of the IsdE lipoprotein in complex with heme. The structure reveals a bi-lobed topology formed by an N- and C-terminal domain bridged by a single {alpha}-helix. The structure places IsdE as a member of the helical backbone metal receptor superfamily. A six-coordinate heme molecule is bound in the groove established at the domain interface, and the heme iron is coordinated in a novel fashion for heme transporters by Met{sup 78} and His{sup 229}. Both heme propionate groups are secured by H-bonds to IsdE main chain and side chain groups. Of these residues, His{sup 299} is essential for IsdE-mediated heme uptake by S. aureus when growth on heme as a sole iron source is measured. Multiple sequence alignments of homologues from several other Gram-positive bacteria, including the human pathogens pyogenes, Bacillus anthracis, and Listeria monocytogenes, suggest that these other systems function equivalently to S. aureus IsdE with respect to heme binding and transport.

  18. The therapeutic effect of Chlorogenic acid against Staphylococcus aureus infection through Sortase A inhibition

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    Lin eWang

    2015-10-01

    Full Text Available The emergence and wide spread of multi-drug resistant Staphylococcus aureus (S. aureus requires the development of new therapeutic agents with alternative modes of action. Anti-virulence strategies are hoped to meet that need. Sortase A (SrtA has attracted great interest as a potential drug target to treat infections caused by S. aureus, as many of the surface proteins displayed by SrtA function as virulence factors by mediating bacterial adhesion to specific organ tissues, invasion of host cells, and evasion of the host-immune responses. It has been suggested that inhibitors of SrtA might be promising candidates for the treatment and/or prevention of S. aureus infections. In this study, we report that Chlorogenic acid (CHA, a natural compound that lacks significant anti–S. aureus activity, inhibit the activity of SrtA in vitro (IC50=33.86±5.55μg/ml and the binding of S. aureus to fibrinogen (Fg. Using molecular dynamics simulations and mutagenesis assays, we further demonstrate that CHA binds to the binding sites of C184 and G192 in the SrtA. In vivo studies demonstrated that CHA prevent mice from S. aureus-induced renal abscess, resulting in a significant survival advantage. These findings indicate that CHA is a promising therapeutic compound against SrtA during S. aureus infections.

  19. Severe Rhabdomyolysis Associated with Staphylococcus aureus Acute Endocarditis Requiring Surgery.

    Science.gov (United States)

    Ravry, Céline; Fedou, Anne-Laure; Dubos, Maria; Denes, Éric; Etchecopar, Caroline; Barraud, Olivier; Vignon, Philippe; François, Bruno

    2015-12-01

    Rhabdomyolysis has multiple etiologies with unclear mechanisms; however, rhabdomyolysis caused by Staphylococcus aureus infection is rare. A case report of severe rhabdomyolysis in a patient who presented with endocarditis caused by methicillin-susceptible S. aureus and review of relevant literature. The patient had a history of cardiac surgery for tetralogy of Fallot. He was admitted to the hospital because of fever and digestive symptoms. Respiratory and hemodynamic status deteriorated rapidly, leading to admission to the intensive care unit (ICU) for mechanical ventilation and vasopressor support. Laboratory tests disclosed severe rhabdomyolysis with a serum concentration of creatine kinase that peaked at 49,068 IU/L; all blood cultures grew methicillin-susceptible S. aureus. Antibiotic therapy was amoxicillin-clavulanic acid, ciprofloxacin, and gentamicin initially and was changed subsequently to oxacillin, clindamycin, and gentamicin. Transesophageal echocardiography showed vegetation on the pulmonary valve, thus confirming the diagnosis of acute endocarditis. Viral testing and computed tomography (CT) scan ruled out any obvious alternative etiology for rhabdomyolysis. Bacterial analysis did not reveal any specificity of the staphylococcal strain. The patient improved with antibiotics and was discharged from the ICU on day 26. He underwent redux surgery for valve replacement on day 53. Staphylococcal endocarditis should be suspected in cases of severe unexplained rhabdomyolysis with acute infectious symptoms.

  20. Long-term mortality and causes of death associated with Staphylococcus aureus bacteremia. A matched cohort study.

    Science.gov (United States)

    Gotland, N; Uhre, M L; Mejer, N; Skov, R; Petersen, A; Larsen, A R; Benfield, T

    2016-10-01

    Data describing long-term mortality in patients with Staphylococcus aureus bacteremia (SAB) is scarce. This study investigated risk factors, causes of death and temporal trends in long-term mortality associated with SAB. Nationwide population-based matched cohort study. Mortality rates and ratios for 25,855 cases and 258,547 controls were analyzed by Poisson regression. Hazard ratio of death was computed by Cox proportional hazards regression analysis. The majority of deaths occurred within the first year of SAB (44.6%) and a further 15% occurred within the following 2-5 years. The mortality rate was 14-fold higher in the first year after SAB and 4.5-fold higher overall for cases compared to controls. Increasing age, comorbidity and hospital contact within 90 days of SAB was associated with an increased risk of death. The overall relative risk of death decreased gradually by 38% from 1992-1995 to 2012-2014. Compared to controls, SAB patients were more likely to die from congenital malformation, musculoskeletal/skin disease, digestive system disease, genitourinary disease, infectious disease, endocrine disease, injury and cancer and less likely to die from respiratory disease, nervous system disease, unknown causes, psychiatric disorders, cardiovascular disease and senility. Over time, rates of death decreased or were stable for all disease categories except for musculoskeletal and skin disease where a trend towards an increase was seen. Long-term mortality after SAB was high but decreased over time. SAB cases were more likely to die of eight specific causes of death and less likely to die of five other causes of death compared to controls. Causes of death decreased for most disease categories. Risk factors associated with long-term mortality were similar to those found for short-term mortality. To improve long-term survival after SAB, patients should be screened for comorbidity associated with SAB. Copyright © 2016 The British Infection Association. Published by

  1. Characterization and regulation of the bovine stearoyl-CoA desaturase gene promoter

    International Nuclear Information System (INIS)

    Keating, Aileen F.; Kennelly, John J.; Zhao Fengqi

    2006-01-01

    The bovine stearoyl-CoA desaturase (Scd) gene plays an important role in the bovine mammary gland where substrates such as stearic and vaccenic acids are converted to oleic acid and conjugated linoleic acid (CLA), respectively. Up to 90% of the CLA in bovine milk is formed due to the action of this enzyme in the mammary gland. The areas of the bovine promoter of importance in regulating this key enzyme were examined and an area of 36 bp in length was identified as having a critical role in transcriptional activation and is designated the Scd transcriptional enhancer element (STE). Electrophoretic mobility shift assay detected three binding complexes on this area in Mac-T cell nuclear extracts. Treatment of cells with CLA caused a significant reduction in transcriptional activity, with this effect being mediated through the STE region. The bovine Scd gene promoter was up-regulated by insulin and down-regulated by oleic acid

  2. A Caenorhabditis elegans Host Model Correlates with Invasive Disease Caused by Staphylococcus aureus Recovered during an Outbreak in Neonatal Intensive Care

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    Kaiyu Wu

    2012-01-01

    Full Text Available BACKGROUND: Caenorhabditis elegans has previously been used as a host model to determine the virulence of clinical methicillin-resistant Staphylococcus aureus isolates. In the present study, methicillin-susceptible S aureus (MSSA strains associated with an outbreak in a neonatal intensive care unit (NICU were investigated using the C elegans model.

  3. Genome Wide Association Study of SNP-, Gene-, and Pathway-based Approaches to Identify Genes Influencing Susceptibility to Staphylococcus aureus Infections

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    Zhan eYe

    2014-05-01

    Full Text Available Background: We conducted a genome-wide association study (GWAS to identify specific genetic variants that underlie susceptibility to disease caused by Staphylococcus aureus in humans. Methods: Cases (n=309 and controls (n=2,925 were genotyped at 508,921 single nucleotide polymorphisms (SNPs. Cases had at least one laboratory and clinician confirmed disease caused by S. aureus whereas controls did not. R-package (for SNP association, EIGENSOFT (to estimate and adjust for population stratification and gene- (VEGAS and pathway-based (DAVID, PANTHER, and Ingenuity Pathway Analysis analyses were performed.Results: No SNP reached genome-wide significance. Four SNPs exceeded the pConclusion: We identified potential susceptibility genes for S. aureus diseases in this preliminary study but confirmation by other studies is needed. The observed associations could be relevant given the complexity of S. aureus as a pathogen and its ability to exploit multiple biological pathways to cause infections in humans.

  4. Staphylococcus aureus ?-Toxin-Dependent Induction of Host Cell Death by Membrane-Derived Vesicles

    OpenAIRE

    Thay, Bernard; Wai, Sun Nyunt; Oscarsson, Jan

    2013-01-01

    Staphylococcus aureus causes a wide spectrum of infections in humans, ranging from superficial cutaneous infections, infections in the circum-oral region, to life-threatening bacteremia. It was recently demonstrated that Gram-positive organisms such as S. aureus liberate membrane-derived vesicles (MVs), which analogously to outer membrane vesicles (OMVs) of Gram-negative bacteria can play a role in delivering virulence factors to host cells. In the present study we have shown that cholesterol...

  5. Evaluation of approaches to monitor Staphylococcus aureus virulence factor expression during human disease.

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    Wouter Rozemeijer

    Full Text Available Staphylococcus aureus is a versatile pathogen of medical significance, using multiple virulence factors to cause disease. A prophylactic S. aureus 4-antigen (SA4Ag vaccine comprising capsular polysaccharide (types 5 and 8 conjugates, clumping factor A (ClfA and manganese transporter C (MntC is under development. This study was designed to characterize S. aureus isolates recovered from infected patients and also to investigate approaches for examining expression of S. aureus vaccine candidates and the host response during human infection. Confirmation of antigen expression in different disease states is important to support the inclusion of these antigens in a prophylactic vaccine. Hospitalized patients with diagnosed S. aureus wound (27 or bloodstream (24 infections were enrolled. Invasive and nasal carriage S. aureus isolates were recovered and characterized for genotypic diversity. S. aureus antigen expression was evaluated directly by real-time, quantitative, reverse-transcriptase PCR (qRT-PCR analysis and indirectly by serology using a competitive Luminex immunoassay. Study isolates were genotypically diverse and all had the genes encoding the antigens present in the SA4Ag vaccine. S. aureus nasal carriage was detected in 55% of patients, and in those subjects 64% of the carriage isolates matched the invasive strain. In swab samples with detectable S. aureus triosephosphate isomerase housekeeping gene expression, RNA transcripts encoding the S. aureus virulence factors ClfA, MntC, and capsule polysaccharide were detected by qRT-PCR. Antigen expression was indirectly confirmed by increases in antibody titer during the course of infection from acute to convalescent phase. Demonstration of bacterial transcript expression together with immunological response to the SA4Ag antigens in a clinically relevant patient population provides support for inclusion of these antigens in a prophylactic vaccine.

  6. Evaluation of approaches to monitor Staphylococcus aureus virulence factor expression during human disease.

    Science.gov (United States)

    Rozemeijer, Wouter; Fink, Pamela; Rojas, Eduardo; Jones, C Hal; Pavliakova, Danka; Giardina, Peter; Murphy, Ellen; Liberator, Paul; Jiang, Qin; Girgenti, Douglas; Peters, Remco P H; Savelkoul, Paul H M; Jansen, Kathrin U; Anderson, Annaliesa S; Kluytmans, Jan

    2015-01-01

    Staphylococcus aureus is a versatile pathogen of medical significance, using multiple virulence factors to cause disease. A prophylactic S. aureus 4-antigen (SA4Ag) vaccine comprising capsular polysaccharide (types 5 and 8) conjugates, clumping factor A (ClfA) and manganese transporter C (MntC) is under development. This study was designed to characterize S. aureus isolates recovered from infected patients and also to investigate approaches for examining expression of S. aureus vaccine candidates and the host response during human infection. Confirmation of antigen expression in different disease states is important to support the inclusion of these antigens in a prophylactic vaccine. Hospitalized patients with diagnosed S. aureus wound (27) or bloodstream (24) infections were enrolled. Invasive and nasal carriage S. aureus isolates were recovered and characterized for genotypic diversity. S. aureus antigen expression was evaluated directly by real-time, quantitative, reverse-transcriptase PCR (qRT-PCR) analysis and indirectly by serology using a competitive Luminex immunoassay. Study isolates were genotypically diverse and all had the genes encoding the antigens present in the SA4Ag vaccine. S. aureus nasal carriage was detected in 55% of patients, and in those subjects 64% of the carriage isolates matched the invasive strain. In swab samples with detectable S. aureus triosephosphate isomerase housekeeping gene expression, RNA transcripts encoding the S. aureus virulence factors ClfA, MntC, and capsule polysaccharide were detected by qRT-PCR. Antigen expression was indirectly confirmed by increases in antibody titer during the course of infection from acute to convalescent phase. Demonstration of bacterial transcript expression together with immunological response to the SA4Ag antigens in a clinically relevant patient population provides support for inclusion of these antigens in a prophylactic vaccine.

  7. Phenotypic and genotypic characterization of antibiotic resistance of methicillin-resistant Staphylococcus aureus isolated from hospital food

    Directory of Open Access Journals (Sweden)

    Farhad Safarpoor Dehkordi

    2017-10-01

    Full Text Available Abstract Background Pathogenic biotypes of the Methicillin-resistant Staphylococcus aureus (MRSA strains are considered to be one of the major cause of food-borne diseases in hospitals. The present investigation was done to study the pattern of antibiotic resistance and prevalence of antibiotic resistance genes of different biotypes of the MRSA strains isolated from various types of hospital food samples. Methods Four-hundred and eighty-five raw and cooked hospital food samples were cultured and MRSA strains were identified using the oxacillin and cefoxitin disk diffusion tests and mecA-based PCR amplification. Isolated strains were subjected to biotyping and their antibiotic resistance patterns were analyzed using the disk diffusion and PCR methods. Results Prevalence of S. aureus and MRSA were 9.69 and 7.62%, respectively. Meat and chicken barbecues had the highest prevalence of MRSA. Prevalence of bovine, ovine, poultry and human-based biotypes in the MRSA strains were 8.10, 8.10, 32.43 and 48.64%, respectively. All of the MRSA strains recovered from soup, salad and rice samples were related to human-based biotypes. MRSA strains harbored the highest prevalence of resistance against penicillin (100%, ceftaroline (100%, tetracycline (100%, erythromycin (89.18% and trimethoprim-sulfamethoxazole (83.78%. TetK (72.97%, ermA (72.97%, msrA (64.86% and aacA-D (62.16% were the most commonly detected antibiotic resistance genes. Conclusions Pattern of antibiotic resistance and also distribution of antibiotic resistance genes were related to the biotype of MRSA strains. Presence of multi-drug resistance and also simultaneous presence of several antibiotic resistance genes in some MRSA isolates showed an important public health issue Further researches are required to found additional epidemiological aspects of the MRSA strains in hospital food samples.

  8. Sero-prevalence of contagious bovine pleuropneumonia and its ...

    African Journals Online (AJOL)

    Abstract. Contagious bovine pleuropneumonia (CBPP) is a disease of cattle caused by ... of veterinary departments have resulted in CBPP running riot in east and ... 5 334 of Sheep, 9 253 of Goat, 72 of Horses, 601 of Mules, 3 300 of Donkeys.

  9. Bovine respiratory syncytial virus : immunopathology and vaccine evaluation

    NARCIS (Netherlands)

    Antonis, A.F.G.

    2010-01-01

    Human and bovine RSVs cause severe disease in humans and in cattle respectively. They have been recognised as important respiratory pathogens in the last five decades, and this has resulted in significant research activities on the pathogenesis and intervention strategies around the world.

  10. Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) at ambient freshwater beaches

    Science.gov (United States)

    Fogarty, Lisa R.; Haack, Sheridan K.; Johnson, Heather E.; Brennan, Angela K.; Isaacs, Natasha M.; Spencer, Chelsea

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) are a threat to human health worldwide, and although detected at marine beaches, they have been largely unstudied at freshwater beaches. Genes indicating S. aureus (SA; femA) and methicillin resistance (mecA) were detected at 11 and 12 of 13 US Great Lakes beaches and in 18% or 27% of 287 recreational water samples, respectively. Eight beaches had mecA + femA (potential MRSA) detections. During an intensive study, higher bather numbers, staphylococci concentrations, and femA detections were found in samples collected after noon than before noon. Local population density, beach cloud cover, and beach wave height were significantly correlated with SA or MRSA detection frequency. The Panton-Valentine leukocidin gene, associated with community-acquired MRSA, was detected in 12 out of 27 potential MRSA samples. The femA gene was detected less frequently at beaches that met US enterococci criteria or EU enterococci ‘excellent’ recreational water quality, but was not related to Escherichia coli-defined criteria. Escherichia coli is often the only indicator used to determine water quality at US beaches, given the economic and healthcare burden that can be associated with infections caused by SA and MRSA, monitoring of recreational waters for non-fecal bacteria such as staphylococci and/or SA may be warranted.

  11. Distinct pathogenesis and host responses during infection of C. elegans by P. aeruginosa and S. aureus.

    Science.gov (United States)

    Irazoqui, Javier E; Troemel, Emily R; Feinbaum, Rhonda L; Luhachack, Lyly G; Cezairliyan, Brent O; Ausubel, Frederick M

    2010-07-01

    The genetically tractable model host Caenorhabditis elegans provides a valuable tool to dissect host-microbe interactions in vivo. Pseudomonas aeruginosa and Staphylococcus aureus utilize virulence factors involved in human disease to infect and kill C. elegans. Despite much progress, virtually nothing is known regarding the cytopathology of infection and the proximate causes of nematode death. Using light and electron microscopy, we found that P. aeruginosa infection entails intestinal distention, accumulation of an unidentified extracellular matrix and P. aeruginosa-synthesized outer membrane vesicles in the gut lumen and on the apical surface of intestinal cells, the appearance of abnormal autophagosomes inside intestinal cells, and P. aeruginosa intracellular invasion of C. elegans. Importantly, heat-killed P. aeruginosa fails to elicit a significant host response, suggesting that the C. elegans response to P. aeruginosa is activated either by heat-labile signals or pathogen-induced damage. In contrast, S. aureus infection causes enterocyte effacement, intestinal epithelium destruction, and complete degradation of internal organs. S. aureus activates a strong transcriptional response in C. elegans intestinal epithelial cells, which aids host survival during infection and shares elements with human innate responses. The C. elegans genes induced in response to S. aureus are mostly distinct from those induced by P. aeruginosa. In contrast to P. aeruginosa, heat-killed S. aureus activates a similar response as live S. aureus, which appears to be independent of the single C. elegans Toll-Like Receptor (TLR) protein. These data suggest that the host response to S. aureus is possibly mediated by pathogen-associated molecular patterns (PAMPs). Because our data suggest that neither the P. aeruginosa nor the S. aureus-triggered response requires canonical TLR signaling, they imply the existence of unidentified mechanisms for pathogen detection in C. elegans, with

  12. Distinct pathogenesis and host responses during infection of C. elegans by P. aeruginosa and S. aureus.

    Directory of Open Access Journals (Sweden)

    Javier E Irazoqui

    2010-07-01

    Full Text Available The genetically tractable model host Caenorhabditis elegans provides a valuable tool to dissect host-microbe interactions in vivo. Pseudomonas aeruginosa and Staphylococcus aureus utilize virulence factors involved in human disease to infect and kill C. elegans. Despite much progress, virtually nothing is known regarding the cytopathology of infection and the proximate causes of nematode death. Using light and electron microscopy, we found that P. aeruginosa infection entails intestinal distention, accumulation of an unidentified extracellular matrix and P. aeruginosa-synthesized outer membrane vesicles in the gut lumen and on the apical surface of intestinal cells, the appearance of abnormal autophagosomes inside intestinal cells, and P. aeruginosa intracellular invasion of C. elegans. Importantly, heat-killed P. aeruginosa fails to elicit a significant host response, suggesting that the C. elegans response to P. aeruginosa is activated either by heat-labile signals or pathogen-induced damage. In contrast, S. aureus infection causes enterocyte effacement, intestinal epithelium destruction, and complete degradation of internal organs. S. aureus activates a strong transcriptional response in C. elegans intestinal epithelial cells, which aids host survival during infection and shares elements with human innate responses. The C. elegans genes induced in response to S. aureus are mostly distinct from those induced by P. aeruginosa. In contrast to P. aeruginosa, heat-killed S. aureus activates a similar response as live S. aureus, which appears to be independent of the single C. elegans Toll-Like Receptor (TLR protein. These data suggest that the host response to S. aureus is possibly mediated by pathogen-associated molecular patterns (PAMPs. Because our data suggest that neither the P. aeruginosa nor the S. aureus-triggered response requires canonical TLR signaling, they imply the existence of unidentified mechanisms for pathogen detection in C

  13. Community-associated methicillin-resistant Staphylococcus aureus infection in Portugal

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    R. Nazareth

    2012-01-01

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA has recently emerged as a cause of community-acquired infections among individuals without risk factors. Community-associated MRSA (CA-MRSA appears to be more virulent, causing superficial mild skin and soft tissue infections to severe necrotizing fasciitis, and in rare cases, pneumonia.Community-associated MRSA was first reported in Australia in the early 80s, after almost two decades in the USA, and then in several countries in Europe, Asia and South America. No data exists in Portugal.We report the first case of CA-MRSA infection in Portugal, in a young adult with severe necrotizing pneumonia, complicated with bilateral empyema and respiratory failure. Resumo: Recentemente assistiu-se à emergência de infeções na comunidade por Staphylococcus aureus meticilina-resistente (MRSA em indivíduos sem fatores de risco. O MRSA associado à comunidade (CA-MRSA parece ser mais virulento, causando desde infeções superficiais da pele e tecidos moles até fasceíte necrosante e, raramente, pneumonia.O CA-MRSA foi inicialmente identificado na Austrália no início da década de 80 e, após cerca de duas décadas, surgiu nos EUA e em vários países da Europa, Ásia e América do Sul. Não existe informação disponível acerca da prevalência em Portugal.Os autores reportam o primeiro caso de infeção por CA-MRSA em Portugal, num adulto jovem com pneumonia necrotizante grave complicada por empiema bilateral e insuficiência respiratória. Keywords: Community-associated, MRSA, Staphylococcus aureus, Necrotizing pneumonia, Empyema, Palavras-chave: comunidade associada, MRSA, Staphylococcus aureus, pneumonia necrosante, empiema

  14. The Staphylococcus aureus α-Acetolactate Synthase ALS Confers Resistance to Nitrosative Stress

    Directory of Open Access Journals (Sweden)

    Sandra M. Carvalho

    2017-07-01

    Full Text Available Staphylococcus aureus is a worldwide pathogen that colonizes the human nasal cavity and is a major cause of respiratory and cutaneous infections. In the nasal cavity, S. aureus thrives with high concentrations of nitric oxide (NO produced by the innate immune effectors and has available for growth slow-metabolizing free hexoses, such as galactose. Here, we have used deep sequencing transcriptomic analysis (RNA-Seq and 1H-NMR to uncover how S. aureus grown on galactose, a major carbon source present in the nasopharynx, survives the deleterious action of NO. We observed that, like on glucose, S. aureus withstands high concentrations of NO when using galactose. Data indicate that this resistance is, most likely, achieved through a distinct metabolism that relies on the increased production of amino acids, such as glutamate, threonine, and branched-chain amino acids (BCAAs. Moreover, we found that under NO stress the S. aureus α-acetolactate synthase (ALS enzyme, which converts pyruvate into α-acetolactate, plays an important role. ALS is proposed to prevent intracellular acidification, to promote the production of BCAAs and the activation of the TCA cycle. Additionally, ALS is shown to contribute to the successful infection of murine macrophages. Furthermore, ALS contributes to the resistance of S. aureus to beta-lactam antibiotics such as methicillin and oxacillin.

  15. Molecular and bacteriological investigation of subclinical mastitis caused by Staphylococcus aureus and Streptococcus agalactiae in domestic bovids from Ismailia, Egypt.

    Science.gov (United States)

    Elhaig, Mahmoud Mohey; Selim, Abdelfattah

    2015-02-01

    A study was carried out to establish the prevalence of subclinical mastitis (SCM) in smallholder dairy farms in Ismailia, Egypt. A total of 340 milking cows and buffaloes were sampled from 60 farms, and 50 nasal swabs were collected from consenting farm workers. Milk samples were subjected to California mastitis test (CMT) and the positive samples were examined by bacterial culture and PCR to identify etiological agents. Based on CMT, the prevalence of SCM was 71.6 % in cattle and 43.5 % in buffaloes while the prevalence was 25.2 % at cow-quarter level and 21.7 % at buffaloes-quarter level. Bacteriological analysis showed that the most frequently identified bacteria were Staphylococcus (S.) aureus (38.3 %) and Streptococcus (Str.) agalactiae (20 %). The diagnostic sensitivity of PCR compared to bacterial culture was superior with S. aureus and Str. agalactiae detection being 41 and 22.6 %, respectively. Furthermore, methicillin-resistant S. aureus (MRSA) strains occurred in 52.2 and 45 % of isolates of animals and workers, respectively. Subclinical mastitis due to S. aureus and Str. agalactiae is endemic in smallholder dairy herds in Ismailia. The occurrence of MRSA in animals and workers highlights a need for wide epidemiological studies of MRSA and adopting control strategies.

  16. A Novel Genetic Group of Bovine Hepacivirus in Archival Serum Samples from Brazilian Cattle

    Directory of Open Access Journals (Sweden)

    Cláudio W. Canal

    2017-01-01

    Full Text Available Hepatitis C virus (HCV (genus Hepacivirus; family Flaviviridae is a major human pathogen causing persistent infection and hepatic injury. Recently, emerging HCV-like viruses were described infecting wild animals, such as bats and rodents, and domestic animals, including dogs, horses, and cattle. Using degenerate primers for detecting bovine pestiviruses in a 1996 survey three bovine serum samples showed a low identity with the genus Pestivirus of the Flaviviridae family. A virus could not be isolated in cell culture. The description of bovine hepaciviruses (BovHepV in 2015 allowed us to retrospectively identify the sequences as BovHepV, with a 88.9% nucleotide identity. In a reconstructed phylogenetic tree, the Brazilian BovHepV samples grouped within the bovine HCV-like cluster in a separated terminal node that was more closely related to the putative bovine Hepacivirus common ancestor than to bovine hepaciviruses detected in Europe and Africa.

  17. Linear peptidomimetics as potent antagonists of Staphylococcus aureus agr quorum sensing

    DEFF Research Database (Denmark)

    Karathanasi, Georgia; Bojer, Martin Saxtorph; Baldry, Mara

    2018-01-01

    Staphylococcus aureus is an important pathogen causing infections in humans and animals. Increasing problems with antimicrobial resistance has prompted the development of alternative treatment strategies, including antivirulence approaches targeting virulence regulation such as the agr quorum...

  18. The analysis of milk components and pathogenic bacteria isolated from bovine raw milk in Korea.

    Science.gov (United States)

    Park, Y K; Koo, H C; Kim, S H; Hwang, S Y; Jung, W K; Kim, J M; Shin, S; Kim, R T; Park, Y H

    2007-12-01

    Bovine mastitis can be diagnosed by abnormalities in milk components and somatic cell count (SCC), as well as by clinical signs. We examined raw milk in Korea by analyzing SCC, milk urea nitrogen (MUN), and the percentages of milk components (milk fat, protein, and lactose). The associations between SCC or MUN and other milk components were investigated, as well as the relationships between the bacterial species isolated from milk. Somatic cell counts, MUN, and the percentages of milk fat, protein, and lactose were analyzed in 30,019 raw milk samples collected from 2003 to 2006. The regression coefficients of natural logarithmic-transformed SCC (SCCt) on milk fat (-0.0149), lactose (-0.8910), and MUN (-0.0096), and those of MUN on milk fat (-0.3125), protein (-0.8012), and SCCt (-0.0671) were negative, whereas the regression coefficient of SCCt on protein was positive (0.3023). When the data were categorized by the presence or absence of bacterial infection in raw milk, SCCt was negatively associated with milk fat (-0.0172), protein (-0.2693), and lactose (-0.4108). The SCCt values were significantly affected by bacterial species. In particular, 104 milk samples infected with Staphylococcus aureus had the highest SCCt (1.67) compared with milk containing other mastitis-causing bacteria: coagulase-negative staphylococci (n = 755, 1.50), coagulase-positive staphylococci (except Staphylococcus aureus; n = 77, 1.59), Streptococcus spp. (Streptococcus dysgalactiae, n = 37; Streptococcus uberis, n = 12, 0.83), Enterococcus spp. (n = 46, 1.04), Escherichia coli (n = 705, 1.56), Pseudomonas spp. (n = 456, 1.59), and yeast (n = 189, 1.52). These results show that high SCC and MUN negatively affect milk components and that a statistical approach associating SCC, MUN, and milk components by bacterial infection can explain the patterns among them. Bacterial species present in raw milk are an important influence on SCC in Korea.

  19. Multilocus Sequence Typing And Antibiotic Resistance Of Staphylococcus Aureus Isolated From The Brazilian Dairy Industry

    DEFF Research Database (Denmark)

    Dittmann, Karen Kiesbye; Chaul, Luiza; Lee, Sarah

    2015-01-01

    Staphylococcus aureus is a common cause of food poisoning due to enterotoxin production. This is particularly an issue in the dairy industry, where S. aureus can contaminate the product e.g. from raw milk or the handlers. In Brazil, soft cheese is mainly produced in small dairy plants where good ...

  20. Methicillin sensitive Staphylococcus aureus producing Panton-Valentine leukocidin toxin in Trinidad & Tobago: a case report

    Directory of Open Access Journals (Sweden)

    Rao AV

    2011-04-01

    Full Text Available Abstract Introduction Certain Staphylococcus aureus strains produce Panton-Valentine leukocidin, a toxin that lyses white blood cells causing extensive tissue necrosis and chronic, recurrent or severe infection. This report documents a confirmed case of methicillin-sensitive Staphylococcus aureus strain harboring Panton-Valentine leukocidin genes from Trinidad and Tobago. To the best of our knowledge, this is the first time that such a case has been identified and reported from this country. Case presentation A 13-year-old Trinidadian boy of African descent presented with upper respiratory symptoms and gastroenteritis-like syptoms. About two weeks later he was re-admitted to our hospital complaining of pain and weakness affecting his left leg, where he had received an intramuscular injection of an anti-emetic drug. He deteriorated and developed septic arthritis, necrotizing fasciitis and septic shock with acute respiratory distress syndrome, leading to death within 48 hours of admission despite intensive care treatment. The infection was caused by S. aureus. Bacterial isolates from specimens recovered from our patient before and after his death were analyzed using microarray DNA analysis and spa typing, and the results revealed that the S. aureus isolates belonged to clonal complex 8, were methicillin-susceptible and positive for Panton-Valentine leukocidin. An autopsy revealed multi-organ failure and histological tissue stains of several organs were also performed and showed involvement of his lungs, liver, kidneys and thymus, which showed Hassal's corpuscles. Conclusion Rapid identification of Panton-Valentine leukocidin in methicillin-sensitive S. aureus isolates causing severe infections is necessary so as not to miss their potentially devastating consequences. Early feedback from the clinical laboratories is crucial.

  1. Microbial Pathogenesis and Host Defense.

    Science.gov (United States)

    1998-03-01

    such diseases as toxic shock syndrome and bovine mastitis . S. aureus cells exhibited dose-dependent invasion of epithelial cells and intracellular...Idaho, Moscow: The internalization of S. aureus by bovine mammary epithelial cells leads to the induction of apoptosis. 130 Drynda, A.,’ Kbnig, B...Microbiology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 The primary virulence factor of the gram-negative, bovine

  2. Diversity of Staphylococcus aureus Isolates in European Wildlife

    Science.gov (United States)

    Monecke, Stefan; Gavier-Widén, Dolores; Hotzel, Helmut; Peters, Martin; Guenther, Sebastian; Lazaris, Alexandros; Loncaric, Igor; Müller, Elke; Reissig, Annett; Ruppelt-Lorz, Antje; Shore, Anna C.; Walter, Birgit; Coleman, David C.; Ehricht, Ralf

    2016-01-01

    Staphylococcus aureus is a well-known colonizer and cause of infection among animals and it has been described from numerous domestic and wild animal species. The aim of the present study was to investigate the molecular epidemiology of S. aureus in a convenience sample of European wildlife and to review what previously has been observed in the subject field. 124 S. aureus isolates were collected from wildlife in Germany, Austria and Sweden; they were characterized by DNA microarray hybridization and, for isolates with novel hybridization patterns, by multilocus sequence typing (MLST). The isolates were assigned to 29 clonal complexes and singleton sequence types (CC1, CC5, CC6, CC7, CC8, CC9, CC12, CC15, CC22, CC25, CC30, CC49, CC59, CC88, CC97, CC130, CC133, CC398, ST425, CC599, CC692, CC707, ST890, CC1956, ST2425, CC2671, ST2691, CC2767 and ST2963), some of which (ST2425, ST2691, ST2963) were not described previously. Resistance rates in wildlife strains were rather low and mecA-MRSA isolates were rare (n = 6). mecC-MRSA (n = 8) were identified from a fox, a fallow deer, hares and hedgehogs. The common cattle-associated lineages CC479 and CC705 were not detected in wildlife in the present study while, in contrast, a third common cattle lineage, CC97, was found to be common among cervids. No Staphylococcus argenteus or Staphylococcus schweitzeri-like isolates were found. Systematic studies are required to monitor the possible transmission of human- and livestock-associated S. aureus/MRSA to wildlife and vice versa as well as the possible transmission, by unprotected contact to animals. The prevalence of S. aureus/MRSA in wildlife as well as its population structures in different wildlife host species warrants further investigation. PMID:27992523

  3. Increased Susceptibility of Humanized NSG Mice to Panton-Valentine Leukocidin and Staphylococcus aureus Skin Infection.

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    Ching Wen Tseng

    Full Text Available Staphylococcus aureus is a leading cause of skin and soft-tissue infections worldwide. Mice are the most commonly used animals for modeling human staphylococcal infections. However a supra-physiologic S. aureus inoculum is required to establish gross murine skin pathology. Moreover, many staphylococcal factors, including Panton-Valentine leukocidin (PVL elaborated by community-associated methicillin-resistant S. aureus (CA-MRSA, exhibit selective human tropism and cannot be adequately studied in mice. To overcome these deficiencies, we investigated S. aureus infection in non-obese diabetic (NOD/severe combined immune deficiency (SCID/IL2rγnull (NSG mice engrafted with human CD34+ umbilical cord blood cells. These "humanized" NSG mice require one to two log lower inoculum to induce consistent skin lesions compared with control mice, and exhibit larger cutaneous lesions upon infection with PVL+ versus isogenic PVL- S. aureus. Neutrophils appear important for PVL pathology as adoptive transfer of human neutrophils alone to NSG mice was sufficient to induce dermonecrosis following challenge with PVL+ S. aureus but not PVL- S. aureus. PMX53, a human C5aR inhibitor, blocked PVL-induced cellular cytotoxicity in vitro and reduced the size difference of lesions induced by the PVL+ and PVL- S. aureus, but PMX53 also reduced recruitment of neutrophils and exacerbated the infection. Overall, our findings establish humanized mice as an important translational tool for the study of S. aureus infection and provide strong evidence that PVL is a human virulence factor.

  4. Control of bovine ringworm by vaccination in Norway.

    Science.gov (United States)

    Lund, Arve; Bratberg, Anna Marie; Næss, Bjørn; Gudding, Roar

    2014-03-15

    Bovine ringworm caused by Trichophyton verrucosum is a notifiable disease in Norway. New infected herds are reported to the Norwegian Food Safety Authority. To limit spread of the disease, restrictions are imposed on holdings including access to common pastures and sale of live animals. Bovine ringworm has been endemic in the Norwegian dairy population for decades. Since 1980 a vaccine (Bovilis Ringvac LTF-130, Merck Animal Health) has been available. The vaccine contains an attenuated strain of T. verrucosum and stimulates humoral and cellular immune responses conferring protection. Efficacy and safety of the vaccine have been evaluated in experimental and field studies. Vaccination campaigns in densely populated counties have contributed to a substantial decrease in number of ringworm outbreaks. The annual incidence of new infected herds decreased from 1.7% in 1980 to 0.043% in 2004. Few herds remained with restrictions and a "mopping up" project was established to offer assistance specifically to these holdings. A milestone was achieved in 2009; no new herds with cases of clinical ringworm caused by T. verrucosum were reported to the authorities. By end of 2012, there are only two herds with restrictions. Vaccination during the last 30 years has been a key control measure in the effort to prevent disease outbreaks and eradicate bovine ringworm in Norway. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Anti-Staphylococcus aureus action of three Caatinga fruits evaluated by electron microscopy.

    Science.gov (United States)

    da Silva, Luís Cláudio Nascimento; Sandes, Jana Messias; de Paiva, Maurício Magalhães; de Araújo, Janete Magali; de Figueiredo, Regina Célia Bressan Queiroz; da Silva, Márcia Vanusa; Correia, Maria Tereza dos Santos

    2013-01-01

    This study evaluated the antibacterial activity of Anadenanthera colubrina, Libidibia ferrea and Pityrocarpa moniliformis fruit extracts against clinical strains of Staphylococcus aureus. The samples were active for all S. aureus strains (minimum inhibitory concentration: 0.38-3.13 mg mL⁻¹), including the multiresistant strain. The morphological changes suggested the cell wall as the main action target. The treated-cells also lose their ability to form aggregates. The analysis suggests cell wall impairment, which causes the loss of viability and death. This study showed for the first time the morphologic alterations involved in the anti-S. aureus action of fruits of A. colubrina, L. ferrea and P. moniliformis. These findings indicated that these fruit extracts are sources of bioactive compounds that can be used as antibacterial agents.

  6. Antibiotic susceptibility pattern and the prevalence of Staphylococcus aureus isolated from skin and soft tissue in Tehran Razi skin hospital (2014-15

    Directory of Open Access Journals (Sweden)

    Zeynab Fagheei-Aghmiyuni

    2017-06-01

    Full Text Available Background: Staphylococcus aureus (S. aureus is the most common cause of skin and soft tissue infections. This study aimed to determine the prevalence of S. aureus isolated from skin and soft tissue and antibiotic susceptibility pattern among the patient hospitalized in Razi skin hospital (Tehran-Iran. Materials and Methods: This cross-sectional study was conducted on patients (n=400 with skin and soft tissue infections in Razi skin hospital. Sterilized swabs were used to collect the skin infection samples. S. aureus isolates were confirmed using biochemical tests (gram staining, catalase, coagulase, DNase test and manitol fermentation tests. Result: 51.3 %( 205 out of 400 of isolates were S. aureus. Ninety six (46.8% of isolates were methicillin and penicillin-resistant S. aureus. All of the isolates showed sensitivity to vancomycin, linezolid. 98% of the isolates were susceptible to daptomycin. One-hundred sixteen (56.6% isolates were multi- drug resistant. Conclusion: More than half of the skin and soft tissue infections were caused by S.aureus. More than 46 percent of the isolates were methicillin resistant. The highest resistance to penicillin was observed.

  7. Methicillin-resistant Staphylococcus aureus transmission

    DEFF Research Database (Denmark)

    Andersen, Leif Percival; Nielsen, Xiaohui

    2015-01-01

    INTRODUCTION: Even though methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of nosocomial infections, it may often be difficult to evaluate the exact route of transmission. METHODS: In this study, we describe four cases of nosocomial transmission of MRSA in a hospital with a low...... increase the risk of contaminating hands, arms and the front of the uniform. Hand hygiene is therefore essential, but the use of protection gowns with long sleeves is also important in order to prevent transmission of MRSA. After culture of MRSA and implementation of specific precautions to prevent...

  8. Udder infections with Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis at calving in dairy herds with suboptimal udder health.

    Science.gov (United States)

    Lundberg, Å; Nyman, A-K; Aspán, A; Börjesson, S; Unnerstad, H Ericsson; Waller, K Persson

    2016-03-01

    Udder infections with Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis are common causes of bovine mastitis. To study these pathogens in early lactation, a 12-mo longitudinal, observational study was carried out in 13 herds with suboptimal udder health. The aims of the study were to investigate the occurrence of these pathogens and to identify if presence of the 3 pathogens, and of genotypes within the pathogens, differed with respect to herd, season, and parity. Quarter milk samples, collected at calving and 4 d in milk (DIM), were cultured for the 3 pathogens. Genotyping of staphylococcal and streptococcal isolates was performed using spa typing and pulsed-field gel electrophoresis, respectively. For each of the 3 pathogens, cows with an udder infection at calving or 4 DIM were allocated to 1 of 4 infection types: cleared (pathogen present only at calving), persistent (pathogen present in the same quarter at calving and 4 DIM), new (pathogen present only at 4 DIM), or cleared/new (pathogen present in 1 quarter at calving and in another quarter at 4 DIM). Associations between season or parity and overall occurrence of pathogens or infection types were determined using univariable mixed-effect logistic-regression models and the Fisher's exact test, respectively. The most commonly occurring pathogen was Staph. aureus, followed by Strep. dysgalactiae and Strep. uberis. Persistent infections were the most common infection type among Staph. aureus-infected cows, whereas cleared infections were the most common among Strep. dysgalactiae- and Strep. uberis-positive cows. The proportion of cows with persistent Staph. aureus infections and the proportion of cows having a Strep. uberis infection at calving or 4 DIM were higher in the multiparous cows than in primiparous cows. Infections with Strep. dysgalactiae were less common during the early housing season than during the late housing or pasture seasons, whereas persistent Strep. uberis

  9. Toxic shock syndrome due to community-acquired methicillin-resistant Staphylococcus aureus infection: Two case reports and a literature review in Japan.

    Science.gov (United States)

    Sada, Ryuichi; Fukuda, Saori; Ishimaru, Hiroyasu

    2017-01-01

    Community-acquired methicillin-resistant Staphylococcus aureus has been spreading worldwide, including in Japan. However, few cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus have been reported in Japan. We report 2 cases, in middle-aged women, of toxic shock syndrome due to Community-acquired methicillin-resistant Staphylococcus aureus via a vaginal portal of entry. The first patient had used a tampon and the second patient had vaginitis due to a cleft narrowing associated with vulvar lichen sclerosus. Both patients were admitted to our hospital with septic shock and severe acute kidney injury and subsequently recovered with appropriate antibiotic treatment. In our review of the literature, 8 cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus were reported in Japan. In these 8 cases, the main portals of entry were the skin and respiratory tract; however, the portal of entry of Community-acquired methicillin-resistant Staphylococcus aureus from a vaginal lesion has not been reported in Japan previously.

  10. DNA aptamers as a novel approach to neutralize Staphylococcus aureus α-toxin.

    Science.gov (United States)

    Vivekananda, Jeevalatha; Salgado, Christi; Millenbaugh, Nancy J

    2014-02-14

    Staphylococcus aureus is a versatile pathogen capable of causing a broad spectrum of diseases ranging from superficial skin infections to life threatening conditions such as endocarditis, septicemia, pneumonia and toxic shock syndrome. In vitro and in vivo studies identified an exotoxin, α-toxin, as a major cause of S. aureus toxicity. Because S. aureus has rapidly evolved resistance to a number of antibiotics, including methicillin, it is important to identify new therapeutic strategies, other than antibiotics, for inhibiting the harmful effects of this pathogen. Aptamers are single-stranded DNA or RNA oligonucleotides with three-dimensional folded conformations that bind with high affinity and selectivity to targets and modulate their biological functions. The goal of this study was to isolate DNA aptamers that specifically inhibit the cytotoxic activity of α-toxin. After 10 rounds of Systematic Evolution of Ligands by EXponential Enrichment (SELEX), 49 potential anti-α-toxin aptamers were identified. In vitro neutralization assays demonstrated that 4 of these 49 aptamers, AT-27, AT-33, AT-36, and AT-49, significantly inhibited α-toxin-mediated cell death in Jurkat T cells. Furthermore, RT-PCR analysis revealed that α-toxin increased the transcription of the inflammatory cytokines TNF-α and IL-17 and that anti-α-toxin aptamers AT-33 and AT-36 inhibited the upregulation of these genes. Collectively, the data suggest the feasibility of generating functionally effective aptamers against α-toxin for treatment of S. aureus infections. Published by Elsevier Inc.

  11. Anti-Bovine Programmed Death-1 Rat–Bovine Chimeric Antibody for Immunotherapy of Bovine Leukemia Virus Infection in Cattle

    Directory of Open Access Journals (Sweden)

    Tomohiro Okagawa

    2017-06-01

    Full Text Available Blockade of immunoinhibitory molecules, such as programmed death-1 (PD-1/PD-ligand 1 (PD-L1, is a promising strategy for reinvigorating exhausted T cells and preventing disease progression in a variety of chronic infections. Application of this therapeutic strategy to cattle requires bovinized chimeric antibody targeting immunoinhibitory molecules. In this study, anti-bovine PD-1 rat–bovine chimeric monoclonal antibody 5D2 (Boch5D2 was constructed with mammalian expression systems, and its biochemical function and antiviral effect were characterized in vitro and in vivo using cattle infected with bovine leukemia virus (BLV. Purified Boch5D2 was capable of detecting bovine PD-1 molecules expressed on cell membranes in flow cytometric analysis. In particular, Biacore analysis determined that the binding affinity of Boch5D2 to bovine PD-1 protein was similar to that of the original anti-bovine PD-1 rat monoclonal antibody 5D2. Boch5D2 was also capable of blocking PD-1/PD-L1 binding at the same level as 5D2. The immunomodulatory and therapeutic effects of Boch5D2 were evaluated by in vivo administration of the antibody to a BLV-infected calf. Inoculated Boch5D2 was sustained in the serum for a longer period. Boch5D2 inoculation resulted in activation of the proliferation of BLV-specific CD4+ T cells and decrease in the proviral load of BLV in the peripheral blood. This study demonstrates that Boch5D2 retains an equivalent biochemical function to that of the original antibody 5D2 and is a candidate therapeutic agent for regulating antiviral immune response in vivo. Clinical efficacy of PD-1/PD-L1 blockade awaits further experimentation with a large number of animals.

  12. Evaluation of Ceftobiprole in a Rabbit Model of Aortic Valve Endocarditis Due to Methicillin-Resistant and Vancomycin-Intermediate Staphylococcus aureus

    OpenAIRE

    Chambers, Henry F.

    2005-01-01

    Ceftobiprole is a novel broad-spectrum cephalosporin that binds with high affinity to PBP 2a, the methicillin-resistance determinant of staphylococci, and is active against methicillin- and vancomycin-resistant Staphylococcus aureus. Ceftobiprole was compared to vancomycin in a rabbit model of methicillin-resistant S. aureus aortic valve endocarditis. Ceftobiprole and vancomycin were equally effective against endocarditis caused by methicillin-resistant S. aureus strain 76, whereas ceftobipro...

  13. Detection of Methicillin Resistance and Various Virulence Factors in Staphylococcus aureus Strains Isolated from Nasal Carriers

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    Hatice Türk Dağı

    2015-06-01

    Full Text Available Background: Staphylococus aureus can be found as a commensal on skin and nasal flora or it may cause local and invasive infections. S. aureus has a large number of virulence factors. Aims: To investigate the methicillin resistance and frequency of various virulence factors in S. aureus nasal isolates. Study Design: Descriptive study. Methods: Nasal samples collected from university students were cultured in media. S. aureus was identified by conventional methods and the Staphyloslide latex test (Becton Dickinson, Sparks, USA. Antibiotic susceptibility tests were conducted, and the methicillin resistance was determined. The mecA, nuc, pvl and staphylococcal toxin genes were examined by polymerase chain reaction (PCR. Results: S. aureus was isolated in 104 of 600 (17.3% nasal samples. In total, 101 (97.1% S. aureus isolates were methicillin-sensitive and the remaining 3 (2.9% were methicillin-resistant. Furthermore, all but five isolates carried at least one staphylococcal enterotoxin gene, with seg being predominant. The tst and eta genes were determined in 29 (27.9%, and 3 (2.9% isolates, respectively. None of the S. aureus isolates harbored see, etb, and pvl genes. Conclusion: A moderate rate of S. aureus carriage and low frequency of MRSA were detected in healthy students. S. aureus isolates had a high prevalence of staphylococcal enterotoxin genes and the tst gene. In this study, a large number of virulence factors were examined in S. aureus nasal isolates, and the data obtained from this study can be used for monitoring the prevalence of virulence genes in S. aureus strains isolated from nasal carriers.

  14. Inhibitory effect of totarol on exotoxin proteins hemolysin and enterotoxins secreted by Staphylococcus aureus.

    Science.gov (United States)

    Shi, Ce; Zhao, Xingchen; Li, Wenli; Meng, Rizeng; Liu, Zonghui; Liu, Mingyuan; Guo, Na; Yu, Lu

    2015-10-01

    Staphylococcus aureus (S. aureus) causes a wide variety of infections, which are of major concern worldwide. S. aureus produces multiple virulence factors, resulting in food infection and poisoning. These virulence factors include hyaluronidases, proteases, coagulases, lipases, deoxyribonucleases and enterotoxins. Among the extracellular proteins produced by S. aureus that contribute to pathogenicity, the exotoxins α-hemolysin, staphylococcal enterotoxin A (SEA) and staphylococcal enterotoxin B (SEB) are thought to be of major significance. Totarol, a plant extract, has been revealed to inhibit the proliferation of several pathogens effectively. However, there are no reports on the effects of totarol on the production of α-hemolysin, SEA or SEB secreted by S. aureus. The aim of this study was to evaluate the effects of totarol on these three exotoxins. Hemolysis assay, western blotting and real-time reverse transcriptase-PCR assay were performed to identify the influence of graded subinhibitory concentrations of totarol on the production of α-hemolysin and the two major enterotoxins, SEA and SEB, by S. aureus in a dose-dependent manner. Moreover, an enzyme linked immunosorbent assay showed that the TNF-α production of RAW264.7 cells stimulated by S. aureus supernatants was inhibited by subinhibitory concentrations of totarol. Form the data, we propose that totarol could potentially be used as a promising natural compound in the food and pharmaceutical industries.

  15. Intracellular persisting Staphylococcus aureus is the major pathogen in recurrent tonsillitis.

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    Andreas E Zautner

    Full Text Available BACKGROUND: The two major indications for tonsillectomy are recurrent tonsillitis (RT and peritonsillar abscess (PTA. Unlike PTAs, which are primarily treated surgically, RT is often cured by tonsillectomy only after a series of failed drug therapy attempts. Although the bacteriological background of RT has been studied, the reason for the lack of success of conservative therapeutic approaches is not well understood. METHODS: In a prospective study, tonsil specimens from 130 RT patients and 124 PTA patients were examined for the presence of extra- and intracellular bacteria using antibiotic protection assays. Staphylococcus aureus isolates from RT patients were characterized by pulsed-field gel electrophoresis (PFGE, spa-typing and MSCRAMM-gene-PCR. Their ability for biofilm formation was tested and their cell invasiveness was confirmed by a flow cytometric invasion assay (FACS, fluorescent in situ hybridization (FISH and immunohistochemistry. FINDINGS: S. aureus was the predominant species (57.7% in RT patients, whereas Streptococcus pyogenes was most prevalent (20.2% in PTA patients. Three different assays (FACS, FISH, antibiotic protection assay showed that nearly all RT-associated S. aureus strains were located inside tonsillar cells. Correspondingly, the results of the MSCRAMM-gene-PCRs confirmed that 87% of these S. aureus isolates were invasive strains and not mere colonizers. Based upon PFGE analyses of genomic DNA and on spa-gene typing the vast majority of the S. aureus isolates belonged to different clonal lineages. CONCLUSIONS: Our results demonstrate that intracellular residing S. aureus is the most common cause of RT and indicate that S. aureus uses this location to survive the effects of antibiotics and the host immune response. A German translation of the Abstract is provided as supplementary material (Abstract S1.

  16. Comparative genomics and the role of lateral gene transfer in the evolution of bovine adapted Streptococcus agalactiae

    Science.gov (United States)

    Richards, Vincent P.; Lang, Ping; Pavinski Bitar, Paulina D.; Lefébure, Tristan; Schukken, Ynte H.; Zadoks, Ruth N.; Stanhope, Michael J.

    2011-01-01

    In addition to causing severe invasive infections in humans, Streptococcus agalactiae, or group B Streptococcus (GBS), is also a major cause of bovine mastitis. Here we provide the first genome sequence for S. agalactiae isolated from a cow diagnosed with clinical mastitis (strain FSL S3-026). Comparison to eight S. agalactiae genomes obtained from human disease isolates revealed 183 genes specific to the bovine strain. Subsequent polymerase chain reaction (PCR) screening for the presence/absence of a subset of these loci in additional bovine and human strains revealed strong differentiation between the two groups (Fisher exact test: p S. agalactiae with Streptococcus uberis (nisin U operon) and Streptococcus dysgalactiae subsp. dysgalactiae (lactose operon). We also found evidence for LGT, involving the salivaricin operon, between the bovine S. agalactiae strain and either Streptococcus pyogenes or Streptococcus salivarius. Our findings provide insight intomechanismsfacilitatingenvironmentaladaptationandacquisitionofpotential virulence factors, while highlighting both the key role LGT has played in the recent evolution of the bovine S. agalactiae strain, and the importance of LGT among pathogens within a shared environment. PMID:21536150

  17. Bats are rare reservoirs of Staphylococcus aureus complex in Gabon.

    Science.gov (United States)

    Held, Jana; Gmeiner, Markus; Mordmüller, Benjamin; Matsiégui, Pierre-Blaise; Schaer, Juliane; Eckerle, Isabella; Weber, Natalie; Matuschewski, Kai; Bletz, Stefan; Schaumburg, Frieder

    2017-01-01

    The colonization of afro-tropical wildlife with Staphylococcus aureus and the derived clade Staphylococcus schweitzeri remains largely unknown. A reservoir in bats could be of importance since bats and humans share overlapping habitats. In addition, bats are food sources in some African regions and can be the cause of zoonotic diseases. Here, we present a cross-sectional survey employing pharyngeal swabs of captured and released bats (n=133) in a forest area of Gabon. We detected low colonization rates of S. aureus (4-6%) and S. schweitzeri (4%) in two out of four species of fruit bats, namely Rousettus aegyptiacus and Micropteropus pusillus, but not in insectivorous bats. Multilocus sequence typing showed that S. aureus from Gabonese bats (ST2984, ST3259, ST3301, ST3302) were distinct from major African human associated clones (ST15, ST121, ST152). S. schweitzeri from bats (ST1697, ST1700) clustered with S. schweitzeri from other species (bats, monkeys) from Nigeria and Côte d'Ivoire. In conclusion, colonization rates of bats with S. aureus and S. schweitzeri were low in our study. Phylogenetic analysis supports an intense geographical dispersal of S. schweitzeri among different mammalian wildlife hosts. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. [Antiviral activity of different drugs in vitro against viruses of bovine infectious rhinotracheitis and bovine diarrhea].

    Science.gov (United States)

    Glotov, A G; Glotova, T I; Sergeev, A A; Belkina, T V; Sergeev, A N

    2004-01-01

    In vitro experiments studied the antiviral activity of 11 different drugs against viruses of bovine infective rhinotracheitis (BIRT) and bovine viral diarrhea (BVD). The 50% inhibiting concentrations of the test agents were determined in the monolayers of MDBK and KCT cell cultures. Only did phosprenyl show a virucidal activity against BIRT virus. All the tested drugs significantly inhibited the reproduction of BIRT virus in the sensitive MDBK cell cultures. Thus, bromuridin, acyclovir, ribavirin and methisazonum inhibited the virus by > or = 100,000 times; liposomal ribavirin, gossypolum, anandinum, polyprenolum, phosprenyl, by 1000-10,000 times; eracond and argovit, by 100 times. In experiments on BVD virus, the cultured KCT cells displayed the antiviral activity of bromuridin, phosprenil, polyprenolum, methisazonum, acyclovir, gossypolum, argovit, and ribavirin (in two variants), which caused a statistically significant (100-10,000-fold) decrease in the productive activity of this virus. Eracond and anandid proved to be ineffective.

  19. The Epidemiology of Methicillin-Resistant Staphylococcus aureus (MRSA) in Germany

    NARCIS (Netherlands)

    Koeck, Robin; Mellmann, Alexander; Schaumburg, Frieder; Friedrich, Alexander W.; Kipp, Frank; Becker, Karsten

    2011-01-01

    Background: For decades, methicillin-resistant Staphylococcus aureus (MRSA) has been a major cause of infection in hospitals and nursing homes (health care-associated MRSA, HA-MRSA). Beginning in the late 1990s, many countries have also experienced a rising incidence of MRSA infection outside of the

  20. Comparative supragenomic analyses among the pathogens Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae Using a modification of the finite supragenome model

    Directory of Open Access Journals (Sweden)

    Yu Susan

    2011-04-01

    Full Text Available Abstract Background Staphylococcus aureus is associated with a spectrum of symbiotic relationships with its human host from carriage to sepsis and is frequently associated with nosocomial and community-acquired infections, thus the differential gene content among strains is of interest. Results We sequenced three clinical strains and combined these data with 13 publically available human isolates and one bovine strain for comparative genomic analyses. All genomes were annotated using RAST, and then their gene similarities and differences were delineated. Gene clustering yielded 3,155 orthologous gene clusters, of which 2,266 were core, 755 were distributed, and 134 were unique. Individual genomes contained between 2,524 and 2,648 genes. Gene-content comparisons among all possible S. aureus strain pairs (n = 136 revealed a mean difference of 296 genes and a maximum difference of 476 genes. We developed a revised version of our finite supragenome model to estimate the size of the S. aureus supragenome (3,221 genes, with 2,245 core genes, and compared it with those of Haemophilus influenzae and Streptococcus pneumoniae. There was excellent agreement between RAST's annotations and our CDS clustering procedure providing for high fidelity metabolomic subsystem analyses to extend our comparative genomic characterization of these strains. Conclusions Using a multi-species comparative supragenomic analysis enabled by an improved version of our finite supragenome model we provide data and an interpretation explaining the relatively larger core genome of S. aureus compared to other opportunistic nasopharyngeal pathogens. In addition, we provide independent validation for the efficiency and effectiveness of our orthologous gene clustering algorithm.

  1. Multiple drug resistance Staphylococcus aureus isolated in foods of ...

    African Journals Online (AJOL)

    Background: StaphylococcuS. aureus is the most important agent, which is known to cause a wide range of diseases in both human and animals. Extended use and misuse of antibiotics in agriculture, stock farming and in the treatment of human diseases, has contributed to the rapid increase of the number of bacteria that ...

  2. LED photochemotherapy against Staphylococcus aureus: an in vitro study

    Science.gov (United States)

    de Oliveira, Susana C. P. S.; Monteiro, Juliana S. C.; Pires-Santos, Gustavo M.; Sampaio, Fernando José Pires; Soares, Luiz Guilherme P.; Soares, Amanda P.; Pinheiro, Antônio L. B.

    2018-02-01

    Bacterial resistance to antibiotics is reality and need for alternative treatments is urgent. The aim of this work was to evaluate, in vitro, the effect of LED photochemotherapy on Staphylococcus aureus (ATCC 23529) using 25 μg / mL of phenothiazine compound combined with LED light (λ632 +/- 2ηm) using 12 J/cm2 energy density. The experiments were carried out in triplicate and the samples were divided into groups: Control, Irradiated (treated only with light), Photosensitizer (treated only in the presence of the dye), LED-Photochemotherapy (treatment with light associated with dye). Counts of the colony forming units and the data obtained were statistically analyzed (ANOVA, Tukey's test, p<0.05). The present study demonstrated that the efficacy of LED-Photochemotherapy as the use of 25 μg/mL x 12 J/cm2 caused 91.57 % of inhibition of bacterial growth. It is concluded that using energy density of 12 J/cm2 associated to 25 μg/mL caused high in vitro inhibition of S. aureus.

  3. Protective effect of bovine milk against HCl and ethanol-induced gastric ulcer in mice.

    Science.gov (United States)

    Yoo, Jeong-Hyun; Lee, Jeong-Sang; Lee, You-Suk; Ku, SaeKwang; Lee, Hae-Jeung

    2018-05-01

    The purpose of this study was to investigate the gastroprotective effects of bovine milk on an acidified ethanol (HCl-ethanol) mixture that induced gastric ulcers in a mouse model. Mice received different doses of commercial fresh bovine milk (5, 10, and 20 mL/kg of body weight) by oral gavage once a day for 14 d. One hour after the last oral administration of bovine milk, the HCl-ethanol mixture was orally intubated to provoke severe gastric damage. Our results showed that pretreatment with bovine milk significantly suppressed the formation of gastric mucosa lesions. Pretreatment lowered gastric myeloperoxidase and increased gastric mucus contents and antioxidant enzymes catalase and superoxide dismutase. Administration of bovine milk increased nitrate/nitrite levels and decreased the malondialdehyde levels and the expression of proinflammatory genes, including transcription factor nuclear factor-κB, cyclooxygenase-2, and inducible nitric oxide synthase in the stomach of mice. These results suggest that bovine milk can prevent the development of gastric ulcer caused by acid and alcohol in mice. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  4. Oligopeptide Targeting Sortase A as Potential Anti-infective Therapy for Staphylococcus aureus

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    Jianfeng Wang

    2018-02-01

    Full Text Available Sortase A (SrtA-catalyzed anchorage of surface proteins in most Gram-positive bacteria is indispensable for their virulence, suggesting that this transpeptidase is a promising target for antivirulence therapy. Here, an oligopeptide, LPRDA, was identified as an effective inhibitor of SrtA via virtual screening based on the LPXTG substrate sequence, and it was found to inhibit SrtA activity in vitro and in vivo (IC50 = 10.61 μM by competitively occupying the active site of SrtA. Further, the oligopeptide treatment had no anti-Staphylococcus aureus activity, but it provided protection against S. aureus-induced mastitis in a mouse model. These findings indicate that the oligopeptide could be used as an effective anti-infective agent for the treatment of infection caused by S. aureus or other Gram-positive bacteria via the targeting of SrtA.

  5. Pseudomonas aeruginosa Alters Staphylococcus aureus Sensitivity to Vancomycin in a Biofilm Model of Cystic Fibrosis Infection

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    Giulia Orazi

    2017-07-01

    Full Text Available The airways of cystic fibrosis (CF patients have thick mucus, which fosters chronic, polymicrobial infections. Pseudomonas aeruginosa and Staphylococcus aureus are two of the most prevalent respiratory pathogens in CF patients. In this study, we tested whether P. aeruginosa influences the susceptibility of S. aureus to frontline antibiotics used to treat CF lung infections. Using our in vitro coculture model, we observed that addition of P. aeruginosa supernatants to S. aureus biofilms grown either on epithelial cells or on plastic significantly decreased the susceptibility of S. aureus to vancomycin. Mutant analyses showed that 2-n-heptyl-4-hydroxyquinoline N-oxide (HQNO, a component of the P. aeruginosa Pseudomonas quinolone signal (PQS system, protects S. aureus from the antimicrobial activity of vancomycin. Similarly, the siderophores pyoverdine and pyochelin also contribute to the ability of P. aeruginosa to protect S. aureus from vancomycin, as did growth under anoxia. Under our experimental conditions, HQNO, P. aeruginosa supernatant, and growth under anoxia decreased S. aureus growth, likely explaining why this cell wall-targeting antibiotic is less effective. P. aeruginosa supernatant did not confer additional protection to slow-growing S. aureus small colony variants. Importantly, P. aeruginosa supernatant protects S. aureus from other inhibitors of cell wall synthesis as well as protein synthesis-targeting antibiotics in an HQNO- and siderophore-dependent manner. We propose a model whereby P. aeruginosa causes S. aureus to shift to fermentative growth when these organisms are grown in coculture, leading to reduction in S. aureus growth and decreased susceptibility to antibiotics targeting cell wall and protein synthesis.

  6. Bovine mastitis: prevalence, risk factors and isolation of Staphylococcus aureus in dairy herds at Hawassa milk shed, South Ethiopia.

    Science.gov (United States)

    Abebe, Rahmeto; Hatiya, Hagere; Abera, Mesele; Megersa, Bekele; Asmare, Kassahun

    2016-12-03

    Mastitis is a disease of major economic importance in dairy industry worldwide. It is of particular concern in developing countries like Ethiopia, where milk and milk products are scarce. The objectives of the study were to estimate the prevalence of mastitis, identify the cow-and herd-level potential risk factors and isolate Staphylococcus aureus, one of etiological agents for contagious mastitis, from cows positive for mastitis. A total of 529 lactating cows selected randomly from 95 herds were screened by California mastitis test (CMT) for sub-clinical mastitis. Also 172 milk samples collected from CMT positive cows were cultured for isolation of S. aureus. Based on CMT result and clinical examination, the prevalence of mastitis at herd-level was 74.7% (95% CI: 64.5, 82.8). The corresponding cow-level prevalence was 62.6% (95% CI: 58.3, 66.7), of which 59.2 and 3.4% were sub-clinical and clinical mastitis cases, respectively. S. aureus was isolated from 51.2% of the milk samples cultured and 73.2% of the herds affected with mastitis. In the multivariable logistic regression model, the herd-level factors significantly associated (p mastitis were herd size, bedding material, and milking mastitic cows last, while at cow-level, breed, parity, stage of lactation, udder and leg hygiene, and teat end shape were noted to have a significant effect on mastitis occurrence. The very high prevalence of mastitis, more importantly the sub-clinical one, in the herds examined revealed the huge potential economic loss the sector suffers. Perhaps this was attributed to lack of implementation of the routine mastitis prevention and control practices by all of the herd owners. The findings of this study warrants the need for strategic approach including dairy extension that focus on enhancing dairy farmers' awareness and practice of hygienic milking, regular screening for sub-clinical mastitis, dry cow therapy and culling of chronically infected cows.

  7. Methicillin-resistant Staphylococcus aureus (MRSA)

    Science.gov (United States)

    Methicillin-resistant Staphylococcus aureus; Hospital-acquired MRSA (HA-MRSA); Staph - MRSA; Staphylococcal - MRSA ... Centers for Disease Control and Prevention website. Methicillin-resistant Staphylococcus aureus (MRSA). www.cdc.gov/mrsa/index.html . Updated ...

  8. A Case of Childhood Lichen Aureus

    OpenAIRE

    Kim, Min Ji; Kim, Byung Yoon; Park, Kyung Chan; Youn, Sang Woong

    2009-01-01

    Lichen aureus is a rare type of chronic pigmented purpuric dermatosis. The eruptions consist of discrete or confluent golden to brownish lichenoid macules and papules, and are usually asymptomatic. Lichen aureus commonly occurs in young adults, but less frequently in children. We report the first case of multiple lichen aureus occurring in a Korean child.

  9. Livestock-Associated Methicillin Resistant and Methicillin Susceptible Staphylococcus aureus Sequence Type (CC)1 in European Farmed Animals: High Genetic Relatedness of Isolates from Italian Cattle Herds and Humans

    DEFF Research Database (Denmark)

    Alba, Patricia; Feltrin, Fabiola; Cordaro, Gessica

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) Sequence Type (ST)1, Clonal Complex( CC) 1, SCCmec V is one of the major Livestock-Associated (LA-) lineages in pig farming industry in Italy and is associated with pigs in other European countries. Recently, it has been increasingly detected...... in Italian dairy cattle herds. The aim of this study was to analyse the differences between ST1 MRSA and methicillin-susceptible S. aureus (MSSA) from cattle and pig herds in Italy and Europe and human isolates. Sixty-tree animal isolates from different holdings and 20 human isolates were characterized...... by pulsed-field gel electrophoresis (PFGE), spa-typing, SCCmec typing, and by micro-array analysis for several virulence, antimicrobial resistance, and strain/host-specific marker genes. Three major PFGE clusters were detected. The bovine isolates shared a high (>= 90% to 100%) similarity with human...

  10. In vitro phagocytosis of methicillin resistant and methicillin sensitive staphylococcus aureus by human polymorphonuclear leucocytes

    International Nuclear Information System (INIS)

    Javed, N.; Tahir, R.; Abbas, A.

    2009-01-01

    Staphylococcus aureus is a gram positive bacterium that causes a number of diseases such as abscesses, infective endocarditis, septic arthritis, etc. It is acquiring resistance against many antibiotics like methicillin; therefore its control is becoming increasingly difficult. Peripheral blood phagocytes particularly polymorphonuclear leucocytes play an important role in the protective mechanisms against these organisms. Phagocytes interact with bacteria and phagocytose these microorganisms to kill them. Phenotypically different isolates of Staphylococcus aureus including methicillin resistant Staphylococcus aureus (MRSA) and methicillin sensitive Staphylococcus aureus (MSSA) were collected from various hospitals of Lahore, Pakistan. Fresh polymorphonuclaer leucocytes were obtained from healthy individuals by centrifugation using Ficol-Hypaque gradient combined with dextran sedimentation. Microbiological method was used for the determination of phagocytic index of phenotypic variants of Staphylococcus aureus. A significant difference was observed between the phagocytic index of both bacterial groups. MSSA group showed the Mean+-SD of 79.46%+-3.9 while MRSA group showed 72.35%+-2.5. Significant difference in phagocytic index indicates that it can be one of the mechanisms of MRSA to evade host immune system as compare to MSSA. (author)

  11. Genome sequencing and analysis reveals possible determinants of Staphylococcus aureus nasal carriage

    Directory of Open Access Journals (Sweden)

    Cole Alexander M

    2008-09-01

    Full Text Available Abstract Background Nasal carriage of Staphylococcus aureus is a major risk factor in clinical and community settings due to the range of etiologies caused by the organism. We have identified unique immunological and ultrastructural properties associated with nasal carriage isolates denoting a role for bacterial factors in nasal carriage. However, despite extensive molecular level characterizations by several groups suggesting factors necessary for colonization on nasal epithelium, genetic determinants of nasal carriage are unknown. Herein, we have set a genomic foundation for unraveling the bacterial determinants of nasal carriage in S. aureus. Results MLST analysis revealed no lineage specific differences between carrier and non-carrier strains suggesting a role for mobile genetic elements. We completely sequenced a model carrier isolate (D30 and a model non-carrier strain (930918-3 to identify differential gene content. Comparison revealed the presence of 84 genes unique to the carrier strain and strongly suggests a role for Type VII secretion systems in nasal carriage. These genes, along with a putative pathogenicity island (SaPIBov present uniquely in the carrier strains are likely important in affecting carriage. Further, PCR-based genotyping of other clinical isolates for a specific subset of these 84 genes raise the possibility of nasal carriage being caused by multiple gene sets. Conclusion Our data suggest that carriage is likely a heterogeneic phenotypic trait and implies a role for nucleotide level polymorphism in carriage. Complete genome level analyses of multiple carriage strains of S. aureus will be important in clarifying molecular determinants of S. aureus nasal carriage.

  12. Investigational drugs to treat methicillin-resistant Staphylococcus aureus

    Science.gov (United States)

    Vuong, Cuong; Yeh, Anthony J; Cheung, Gordon YC; Otto, Michael

    2016-01-01

    Introduction Staphylococcus aureus remains one of the leading causes of morbidity and mortality worldwide. This is to a large extent due to antibiotic-resistant strains, in particular methicillin-resistant S. aureus (MRSA). While the toll of invasive MRSA infections appears to decrease in U.S. hospitals, the rate of community-associated MRSA infections remains constant and there is a surge of MRSA in many other countries. This situation calls for continuing if not increased efforts to find novel strategies to combat MRSA infections. Areas covered This review will provide an overview of current investigational antibiotics in clinical development (up to phase II), and of therapeutic antibodies and alternative drugs against S. aureus in preclinical and clinical development, including a short description of the mechanism of action and a presentation of microbiological and clinical data. Expert opinion Increased recent antibiotic development efforts and results from pathogenesis research have led to several new antibiotics and alternative drugs, as well as a more informed selection of targets for vaccination efforts against MRSA. This developing portfolio of novel anti-staphylococcal drugs will hopefully provide us with additional and more efficient ways to combat MRSA infections in the near future and prevent us from running out of treatment options, even if new resistances arise. PMID:26536498

  13. Generation of a persistently infected MDBK cell line with natural bovine spongiform encephalopathy (BSE.

    Directory of Open Access Journals (Sweden)

    Dongseob Tark

    Full Text Available Bovine spongiform encephalopathy (BSE is a zoonotic transmissible spongiform encephalopathy (TSE thought to be caused by the same prion strain as variant Creutzfeldt-Jakob disease (vCJD. Unlike scrapie and chronic wasting disease there is no cell culture model allowing the replication of proteinase K resistant BSE (PrPBSE and the further in vitro study of this disease. We have generated a cell line based on the Madin-Darby Bovine Kidney (MDBK cell line over-expressing the bovine prion protein. After exposure to naturally BSE-infected bovine brain homogenate this cell line has shown to replicate and accumulate PrPBSE and maintain infection up to passage 83 after initial challenge. Collectively, we demonstrate, for the first time, that the BSE agent can infect cell lines over-expressing the bovine prion protein similar to other prion diseases. These BSE infected cells will provide a useful tool to facilitate the study of potential therapeutic agents and the diagnosis of BSE.

  14. Alpha-Toxin Promotes Mucosal Biofilm Formation by Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Michele J Anderson

    2012-05-01

    Full Text Available Staphylococcus aureus causes numerous diseases in humans ranging from the mild skin infections to serious, life-threatening, superantigen-mediated Toxic Shock Syndrome (TSS. S. aureus may also be asymptomatically carried in the anterior nares, vagina or on the skin, which serve as reservoirs for infection. Pulsed-field gel electrophoresis clonal type USA200 is the most widely disseminated colonizer and a major cause of TSS. Our prior studies indicated that α-toxin was a major epithelial proinflammatory exotoxin produced by TSS S. aureus USA200 isolates. It also facilitated the penetration of TSS Toxin-1 (TSST-1 across vaginal mucosa. However, the majority of menstrual TSS isolates produce low α-toxin due to a nonsense point mutation at codon 113, designated hly, suggesting mucosal adaptation. The aim of this study was to characterize the differences between TSS USA200 strains [high (hla+ and low (hly+ α-toxin producers] in their abilities to infect and disrupt vaginal mucosal tissue. A mucosal model was developed using ex vivo porcine vaginal mucosa, LIVE/DEAD® staining and confocal microscropy to characterize biofilm formation and tissue viability of TSS USA 200 isolates CDC587 and MN8, which contain the α-toxin pseudogene (hly, MNPE (hla+ and MNPE isogenic hla knockout (hlaKO. All TSS strains grew to similar bacterial densities (1-5 x 108 CFU on the mucosa and were proinflammatory over 3 days. However, MNPE formed biofilms with significant reductions in the mucosal viability whereas neither CDC587, MN8 (hly+, or MNPE hlaKO, formed biofilms and were less cytotoxic. The addition of exogenous, purified α-toxin to MNPE hlaKO restored the biofilm phenotype. Our studies suggest α-toxin affects S. aureus phenotypic growth on vaginal mucosa, by promoting tissue disruption and biofilm formation; and α–toxin mutants (hly are not benign colonizers, but rather form a different type of infection, which we have termed high density pathogenic

  15. Preventing Community-Associated Methicillin-Resistant "Staphylococcus aureus" among Student Athletes

    Science.gov (United States)

    Many, Patricia S.

    2008-01-01

    Methicillin-resistant "Staphylococcus aureus" (MRSA) was once thought to be a bacterium causing infections in only hospitalized patients. However, a new strain of MRSA has emerged among healthy individuals who have not had any recent exposure to a hospital or to medical procedures. This new strain is known as "community-associated…

  16. Clonal profile, virulence and resistance of Staphylococcus aureus isolated from sheep milk.

    Science.gov (United States)

    Martins, Katheryne Benini; Faccioli-Martins, Patricia Yoshida; Riboli, Danilo Flávio Moraes; Pereira, Valéria Cataneli; Fernandes, Simone; Oliveira, Aline A; Dantas, Ariane; Zafalon, Luiz Francisco; da Cunha, Maria de Lourdes Ribeiro de Souza

    2015-06-01

    The objective of this study was to characterize the clonal profile, virulence factors and antimicrobial resistance, particularly oxacillin resistance, of Staphylococcus aureus isolated from sheep milk. Milk samples were collected from all teats for the California Mastitis Test (CMT), somatic cell count, identification of S. aureus, investigation in these strains of genes encoding toxins (sea, seb, sec, sed, tst), biofilm (icaA, icaC, icaD, bap), leukocidin (luk-PV) oxacillin resistance by mecA gene detection and susceptibility testing (12 antibiotics). Messenger RNA expression was evaluated by RT-PCR in isolates carrying toxin and biofilm genes. Biofilm formation was also evaluated phenotypically by adherence to polystyrene plates. The clonal profile of S. aureus was investigated by pulsed-field gel electrophoresis. A total of 473 milk samples were collected from 242 animals on three farms and 20 S. aureus strains were isolated and none carried the mecA gene. The two sec gene-positive isolates and the isolates carrying the tst and luk-PV genes were positive by RT-PCR. Staphylococcus aureus isolated from the three flocks studied showed high susceptibility to the drugs tested and none was biofilm producer, indicating that biofilm formation was not a virulence factor causing infection by these strains. The typing of 17 S. aureus isolates revealed the presence of a common clone on the three farms studied, and the presence and expression of the sec and tst genes in one strain of this clone suggest the possible acquisition of virulence genes by this clone, a fact that is important for animal health and food hygiene.

  17. Clonal profile, virulence and resistance of Staphylococcus aureus isolated from sheep milk

    Science.gov (United States)

    Martins, Katheryne Benini; Faccioli-Martins, Patricia Yoshida; Riboli, Danilo Flávio Moraes; Pereira, Valéria Cataneli; Fernandes, Simone; Oliveira, Aline A.; Dantas, Ariane; Zafalon, Luiz Francisco; da Cunha, Maria de Lourdes Ribeiro de Souza

    2015-01-01

    The objective of this study was to characterize the clonal profile, virulence factors and antimicrobial resistance, particularly oxacillin resistance, of Staphylococcus aureus isolated from sheep milk. Milk samples were collected from all teats for the California Mastitis Test (CMT), somatic cell count, identification of S. aureus, investigation in these strains of genes encoding toxins (sea, seb, sec, sed, tst), biofilm (icaA, icaC, icaD, bap), leukocidin (luk-PV) oxacillin resistance by mecA gene detection and susceptibility testing (12 antibiotics). Messenger RNA expression was evaluated by RT-PCR in isolates carrying toxin and biofilm genes. Biofilm formation was also evaluated phenotypically by adherence to polystyrene plates. The clonal profile of S. aureus was investigated by pulsed-field gel electrophoresis. A total of 473 milk samples were collected from 242 animals on three farms and 20 S. aureus strains were isolated and none carried the mecA gene. The two sec gene-positive isolates and the isolates carrying the tst and luk-PV genes were positive by RT-PCR. Staphylococcus aureus isolated from the three flocks studied showed high susceptibility to the drugs tested and none was biofilm producer, indicating that biofilm formation was not a virulence factor causing infection by these strains. The typing of 17 S. aureus isolates revealed the presence of a common clone on the three farms studied, and the presence and expression of the sec and tst genes in one strain of this clone suggest the possible acquisition of virulence genes by this clone, a fact that is important for animal health and food hygiene. PMID:26273271

  18. Staphylococcus aureus α-Toxin: Nearly a Century of Intrigue

    Directory of Open Access Journals (Sweden)

    Bryan J. Berube

    2013-06-01

    Full Text Available Staphylococcus aureus secretes a number of host-injurious toxins, among the most prominent of which is the small β-barrel pore-forming toxin α-hemolysin. Initially named based on its properties as a red blood cell lytic toxin, early studies suggested a far greater complexity of α-hemolysin action as nucleated cells also exhibited distinct responses to intoxication. The hemolysin, most aptly referred to as α-toxin based on its broad range of cellular specificity, has long been recognized as an important cause of injury in the context of both skin necrosis and lethal infection. The recent identification of ADAM10 as a cellular receptor for α-toxin has provided keen insight on the biology of toxin action during disease pathogenesis, demonstrating the molecular mechanisms by which the toxin causes tissue barrier disruption at host interfaces lined by epithelial or endothelial cells. This review highlights both the historical studies that laid the groundwork for nearly a century of research on α-toxin and key findings on the structural and functional biology of the toxin, in addition to discussing emerging observations that have significantly expanded our understanding of this toxin in S. aureus disease. The identification of ADAM10 as a proteinaceous receptor for the toxin not only provides a greater appreciation of truths uncovered by many historic studies, but now affords the opportunity to more extensively probe and understand the role of α-toxin in modulation of the complex interaction of S. aureus with its human host.

  19. Characterization of a Staphylococcus aureus surface virulence factor that promotes resistance to oxidative killing and infectious endocarditis.

    Science.gov (United States)

    Malachowa, Natalia; Kohler, Petra L; Schlievert, Patrick M; Chuang, Olivia N; Dunny, Gary M; Kobayashi, Scott D; Miedzobrodzki, Jacek; Bohach, Gregory A; Seo, Keun Seok

    2011-01-01

    Staphylococcus aureus is a prominent human pathogen and a leading cause of community- and hospital-acquired bacterial infections worldwide. Herein, we describe the identification and characterization of the S. aureus 67.6-kDa hypothetical protein, named for the surface factor promoting resistance to oxidative killing (SOK) in this study. Sequence analysis showed that the SOK gene is conserved in all sequenced S. aureus strains and homologous to the myosin cross-reactive antigen of Streptococcus pyogenes. Immunoblotting and immunofluorescence analysis showed that SOK was copurified with membrane fractions and was exposed on the surface of S. aureus Newman and RN4220. Comparative analysis of wild-type S. aureus and an isogenic deletion strain indicated that SOK contributes to both resistance to killing by human neutrophils and to oxidative stress. In addition, the S. aureus sok deletion strain showed dramatically reduced aortic valve vegetation and bacterial cell number in a rabbit endocarditis model. These results, plus the suspected role of the streptococcal homologue in certain diseases such as acute rheumatic fever, suggest that SOK plays an important role in cardiovascular and other staphylococcal infections.

  20. A 12-year review of Staphylococcus aureus bloodstream infections in haemodialysis patients: more work to be done.

    LENUS (Irish Health Repository)

    Fitzgerald, S F

    2012-02-01

    Staphylococcus aureus bloodstream infections (BSI) are a significant cause of morbidity and mortality in haemodialysis patients. This study describes a 12-year retrospective review of S. aureus BSI in a large haemodialysis centre in a tertiary referral hospital. The overall rate of S. aureus BSI was 17.9 per 100 patient-years (range 9.7-36.8). The rate of meticillin-resistant S. aureus (MRSA) BSI was 5.6 per 100 patient-years (range 0.9-13.8). Infective complications occurred in 11% of episodes, the most common being infective endocarditis (7.6%). Ten percent of patients died within 30 days of S. aureus being isolated from blood. Most cases of S. aureus BSI (83%) were related to vascular catheters. The provision of lower-risk vascular access, such as arteriovenous fistulae, and reduced use of intravascular catheters should be priorities in all haemodialysis units. Where alternative vascular access cannot be established, interventions to reduce the risk of catheter-related infections should be implemented to reduce morbidity and mortality in this vulnerable patient group.

  1. Epidemiology of Streptococcus pneumoniae and Staphylococcus aureus colonization in healthy Venezuelan children.

    Science.gov (United States)

    Quintero, B; Araque, M; van der Gaast-de Jongh, C; Escalona, F; Correa, M; Morillo-Puente, S; Vielma, S; Hermans, P W M

    2011-01-01

    Streptococcus pneumoniae and Staphylococcus aureus cause significant morbidity and mortality worldwide. We investigated both the colonization and co-colonization characteristics for these pathogens among 250 healthy children from 2 to 5 years of age in Merida, Venezuela, in 2007. The prevalence of S. pneumoniae colonization, S. aureus colonization, and S. pneumoniae-S. aureus co-colonization was 28%, 56%, and 16%, respectively. Pneumococcal serotypes 6B (14%), 19F (12%), 23F (12%), 15 (9%), 6A (8%), 11 (8%), 23A (6%), and 34 (6%) were the most prevalent. Non-respiratory atopy was a risk factor for S. aureus colonization (p = 0.017). Vaccine serotypes were negatively associated with preceding respiratory infection (p = 0.02) and with S. aureus colonization (p = 0.03). We observed a high prevalence of pneumococcal resistance against trimethoprim-sulfamethoxazole (40%), erythromycin (38%), and penicillin (14%). Semi-quantitative measurement of pneumococcal colonization density showed that children with young siblings and low socioeconomic status were more densely colonized (p = 0.02 and p = 0.02, respectively). In contrast, trimethoprim-sulfamethoxazole- and multidrug-resistant-pneumococci colonized children sparsely (p = 0.03 and p = 0.01, respectively). Our data form an important basis to monitor the future impact of pneumococcal vaccination on bacterial colonization, as well as to recommend a rationalized and restrictive antimicrobial use in our community.

  2. A natural human monoclonal antibody targeting Staphylococcus Protein A protects against Staphylococcus aureus bacteremia

    Science.gov (United States)

    Varshney, Avanish K.; Sunley, Kevin M.; Bowling, Rodney A.; Kwan, Tzu-Yu; Mays, Heather R.; Rambhadran, Anu; Zhang, Yanfeng; Martin, Rebecca L.; Cavalier, Michael C.; Simard, John

    2018-01-01

    Staphylococcus aureus can cause devastating and life-threatening infections. With the increase in multidrug resistant strains, novel therapies are needed. Limited success with active and passive immunization strategies have been attributed to S. aureus immune evasion. Here, we report on a monoclonal antibody, 514G3, that circumvents a key S. aureus evasion mechanism by targeting the cell wall moiety Protein A (SpA). SpA tightly binds most subclasses of immunoglobulins via their Fc region, neutralizing effector function. The organism can thus shield itself with a protective coat of serum antibodies and render humoral immunity ineffective. The present antibody reactivity was derived from an individual with natural anti-SpA antibody titers. The monoclonal antibody is of an IgG3 subclass, which differs critically from other immunoglobulin subclasses since its Fc is not bound by SpA. Moreover, it targets a unique epitope on SpA that allows it to bind in the presence of serum antibodies. Consequently, the antibody opsonizes S. aureus and maintains effector function to enable natural immune mediated clearance. The data presented here provide evidence that 514G3 antibody is able to successfully rescue mice from S. aureus mediated bacteremia. PMID:29364906

  3. Analysis of as a cause of foodborne illness and its associated differential diagnosis

    Directory of Open Access Journals (Sweden)

    Sung Uk Lee

    2017-03-01

    Full Text Available OBJECTIVES Recently kudoa septempuctata in olive flounders is suggested as a cause of food poisoning, however whether kudoa septempuctata can affect human gastrointestinal systems is controversial and its pathogenecity remains unclear. In view of the field epidemiology, food poisonings caused by kudoa septempuctata should be distinguished from those caused by Staphylococcus aureus and bacillus cereus. METHODS The statistics of food poisoning investigations published by Korea Centers for Disease Control and Prevention in 2013-2015 were reviewed. The characteristics of kudoa septempuctata food poisoning reported by Korea Centers for Disease Control and Prevention were reviewed. Information regarding clinical symptoms or epidemiology was extracted. RESULTS Total eleven kudoa septempuctata food poisoning cases were analyzed. Food poisonings caused by kudoa septempuctata, Staphylococcus aureus and bacillus cereus have clinical and epidemiological similarities. Forty five percent of food poisoning outbreaks occurred in Korea was concluded as unknown. The food poisoning caused by Staphylococcus aureus and bacillus cereus accounted for 4.5% (50/1,092 of all food poisoning outbreaks in Korea between 2013 and 2015. CONCLUSIONS This study suggests the possibilities of misdiagnosis in the investigations of food poisoning by Staphylococcus aureus and bacillus cereus with kudoa septempuctata.

  4. Genomic evolution of Staphylococcus aureus isolates colonizing the nares and progressing to bacteremia.

    Directory of Open Access Journals (Sweden)

    Jeanne B Benoit

    Full Text Available Nasal colonization by Staphylococcus aureus is a key risk factor for bacteremia. The objective of this study is to identify genomic modifications occurring in nasal carriage strains of S. aureus as they progress to bacteremia in a cohort of hospitalized patients.Eight patients with S. aureus bacteremia were identified. Genomic sequences of the bloodstream isolates were compared with 57 nasal isolates collected longitudinally prior to the occurrence of bacteremia, which covered a timespan of up to 326 days before bacteremia.Within each subject, nasal colonizing strains were closely related to bacteremia strains. Within a subject, the number of single nucleotide polymorphisms (SNPs observed between time points was greater than within a single time point. Co-colonization and strain replacement were observed in one case. In all cases colonization progressed to bacteremia without addition of new virulence genes. In one case, a mutation in the accessory gene regulator gene caused abrogation of agr function.S. aureus evolves in the human nares at a variable rate. Progression of S. aureus nasal colonization to nosocomial infection is seldom associated with acquisition of new virulence determinants. Mutation in the agr gene with abrogation of function was associated with progression to bacteremia in one case.

  5. Staphylococcus aureus utilizes host-derived lipoprotein particles as sources of exogenous fatty acids.

    Science.gov (United States)

    Delekta, Phillip C; Shook, John C; Lydic, Todd A; Mulks, Martha H; Hammer, Neal D

    2018-03-26

    Methicillin-resistant Staphylococcus aureus (MRSA) is a threat to global health. Consequently, much effort has focused on the development of new antimicrobials that target novel aspects of S. aureus physiology. Fatty acids are required to maintain cell viability, and bacteria synthesize fatty acids using the type II fatty acid synthesis pathway (FASII). FASII is significantly different from human fatty acid synthesis, underscoring the therapeutic potential of inhibiting this pathway. However, many Gram-positive pathogens incorporate exogenous fatty acids, bypassing FASII inhibition and leaving the clinical potential of FASII inhibitors uncertain. Importantly, the source(s) of fatty acids available to pathogens within the host environment remains unclear. Fatty acids are transported throughout the body by lipoprotein particles in the form of triglycerides and esterified cholesterol. Thus, lipoproteins, such as low-density lipoprotein (LDL) represent a potentially rich source of exogenous fatty acids for S. aureus during infection. We sought to test the ability of LDLs to serve as a fatty acid source for S. aureus and show that cells cultured in the presence of human LDLs demonstrate increased tolerance to the FASII inhibitor, triclosan. Using mass spectrometry, we observed that host-derived fatty acids present in the LDLs are incorporated into the staphylococcal membrane and that tolerance to triclosan is facilitated by the fatty acid kinase A, FakA, and Geh, a triacylglycerol lipase. Finally, we demonstrate that human LDLs support the growth of S. aureus fatty acid auxotrophs. Together, these results suggest that human lipoprotein particles are a viable source of exogenous fatty acids for S. aureus during infection. IMPORTANCE Inhibition of bacterial fatty acid synthesis is a promising approach to combating infections caused by S. aureus and other human pathogens. However, S. aureus incorporates exogenous fatty acids into its phospholipid bilayer. Therefore, the

  6. Evaluation of genetically inactivated alpha toxin for protection in multiple mouse models of Staphylococcus aureus infection.

    Directory of Open Access Journals (Sweden)

    Rebecca A Brady

    Full Text Available Staphylococcus aureus is a major human pathogen and a leading cause of nosocomial and community-acquired infections. Development of a vaccine against this pathogen is an important goal. While S. aureus protective antigens have been identified in the literature, the majority have only been tested in a single animal model of disease. We wished to evaluate the ability of one S. aureus vaccine antigen to protect in multiple mouse models, thus assessing whether protection in one model translates to protection in other models encompassing the full breadth of infections the pathogen can cause. We chose to focus on genetically inactivated alpha toxin mutant HlaH35L. We evaluated the protection afforded by this antigen in three models of infection using the same vaccine dose, regimen, route of immunization, adjuvant, and challenge strain. When mice were immunized with HlaH35L and challenged via a skin and soft tissue infection model, HlaH35L immunization led to a less severe infection and decreased S. aureus levels at the challenge site when compared to controls. Challenge of HlaH35L-immunized mice using a systemic infection model resulted in a limited, but statistically significant decrease in bacterial colonization as compared to that observed with control mice. In contrast, in a prosthetic implant model of chronic biofilm infection, there was no significant difference in bacterial levels when compared to controls. These results demonstrate that vaccines may confer protection against one form of S. aureus disease without conferring protection against other disease presentations and thus underscore a significant challenge in S. aureus vaccine development.

  7. Intracellular activity of clinical concentrations of phenothiazines including thioridiazine against phagocytosed Staphylococcus aureus.

    Science.gov (United States)

    Ordway, Diane; Viveiros, Miguel; Leandro, Clara; Arroz, Maria Jorge; Amaral, Leonard

    2002-07-01

    The effect of thioridazine (TZ) was studied on the killing activity of human peripheral blood monocyte derived macrophages (HPBMDM) and of human macrophage cell line THP-1 at extracellular concentrations below those achievable clinically. These macrophages have nominal killing activity against bacteria and therefore, would not influence any activity that the compounds may have against intracellular localised Staphylococcus aureus. The results indicated that whereas TZ has an in vitro minimum inhibitory concentration (MIC) against the strains of S. aureus of 18, 0.1 mg/l of TZ in the medium completely inhibits the growth of S. aureus that has been phagocytosed by macrophages. The latter concentration was non-toxic to macrophages, did not cause cellular expression of activation marker CD69 nor induction of CD3+ T cell production of IFN-gamma, but blocked cellular proliferation and down-regulated the production of T cell-derived cytokines (IFN-gamma, IL-5). These results suggest that TZ induces intracellular bactericidal activities independent of the capacity to generate Type 1 responses against S. aureus.

  8. Antibiotic susceptibility pattern of staphylococcus aureus and methicillin-resistant staphylococcus aureus in a tertiary care hospital

    Directory of Open Access Journals (Sweden)

    CP Bhatt

    2014-04-01

    Full Text Available Background: Methicillin resistant Staphylococcus aureushas emerged as one of the most important nosocomial pathogens. It invokes a tremendous financial burden and enhanced morbidity and mortality due to difficult to treat systemic infections.Aim of this study was to determine antibiotic susceptibility pattern of Staphylococcus aureus and Methicillin resistant Staphylococcus aureus. Materials and Methods: Different clinical specimens were collected and processed for routine culture and antibiotic sensitivity test by standard microbiology techniques. Results: Out of 1173 samples received for microbiological examination, 100 were found to be S. aureus with 19% cases were Methicillin resistant Staphylococcus aureus (MRSA. Fourteen MRSA were found from inpatient and 5 were from outpatient. MRSA was found higher in female than male and maximum number (31.5% was found in age group 0-10 years. Staphylococcus aureus was 100% sensitive to Vancomycin followed by Amikacin (90%, Gentamycin (83%, and tetracycline (81%. On urine isolates Nitrofurantoin(91.6% was drug of choice. All the isolates were resistant to Penicillin G. In case of Methicillin resistant Staphylococcus aureus showed 100% sensitive to Vancomycin followed by Amikacin (84.2%, Tetracycline (63.1%, Ciprofloxacin (42% and Gentamycin (36.8%. Among urine isolates Nitrofutantoin showed 87.5% sensitive followed by Norfloxacin (75%. Conclusion: Methicillin resistant Staphylococcus aureus was found 19% of Staphylococcus aureus isolates. It was most common in females, hospitalized patients and young age group. Vancomycin seems to be drug of choice followed by Amikacin. It would be helpful to formulating and monitoring the antibiotic policy and ensure proper empiric treatment. DOI: http://dx.doi.org/10.3126/jpn.v4i7.10297 Journal of Pathology of Nepal (2014 Vol. 4, 548-551   

  9. Bovine respiratory syncytial virus (BRSV): A review

    DEFF Research Database (Denmark)

    Larsen, Lars Erik

    2000-01-01

    Bovine respiratory syncytial virus (BRSV) infection is the major cause of respiratory disease in calves during the first year of life. The study of the virus has been difficult because of its lability and very poor growth in cell culture. However, during the last decade, the introduction of new...... complex and unpredictable which makes the diagnosis and subsequent therapy very difficult. BRSV is closely related to human respiratory syncytial virus (HRSV) which is an important cause of respiratory disease in young children. In contrast to BRSV, the recent knowledge of HRSV is regularly extensively...

  10. Bovine lymphocytic leukemia: studies of etiology, pathogenesis and mode of transmission. Progress report No. 18, June 1975--June 1978

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, D.K.

    1978-07-01

    The primary objective of this research is to elucidate the cause(s) and early pathogenesis of the adult form of lymphosarcoma in cattle. Consequently, a major portion of our research is centered around experimental transmission of this disease. Bovine leukemia is believed to be caused by an oncogenic RNA virus designated bovine leukemia virus (BLV). We have consistently demonstrated the presence of BLV particles in leukemic cattle and cattle with a persistent lymphocytosis, but never in normal cattle. These BLV particles have been partially purified and highly concentrated to provide a potent inoculum used to inoculate 12 late stage bovine fetuses (in utero) and two newborn calves. Our current study involves extensive monitoring of these inoculated animals to detect early precancerous changes and obtain a detailed description of the events occurring early in the pathogenesis of bovine lymphosarcoma. From our ongoing monitoring study we will be able to detail when, in what sequence, and to what extent each parameter changes in the course of lymphosarcoma development. In addition to our transmission and monitoring studies we are examining various lymphocyte subpopulations in an attempt to determine which cell type is responsible for BLV production and to determine if this same cell type carries the nuclear pocket abnormality associated with the adult form of bovine lymphosarcoma. (ERB)

  11. The importance of subcutaneous abscess infection by Pasteurella spp. and Staphylococcus aureus as a cause of meat condemnation in slaughtered commercial rabbits

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    A. Ferreira

    2014-12-01

    Full Text Available Subcutaneous abscesses are lesions frequently reported in commercial rabbits. Both at farm and slaughterhouse level, these lesions are responsible for economic losses and a potential decrease in meat quality. The present study was devised to identify the main causes of meat condemnation in slaughtered commercial rabbits and assess the importance of abscess lesions in this domain. For these purposes, 281423 rabbits were evaluated during meat inspection at the slaughterhouse. The results achieved showed that subcutaneous abscesses were the major cause of condemnation, being responsible for the rejection of 1355 (0.48% rabbit carcasses. The main affected area was the hind limbs (31.37%, followed by the cervical area (23.10%. Microbiological analyses of 27 abscess samples indicated Pasteurella spp. as the bacteria mostly isolated (59.3%, followed by Staphylococcus aureus (25.9%. These results enable us to advise the industry on the significance of abscesses as an important cause of economic losses, due to meat condemnation during post mortem inspection, and highlight the importance of implementing monitoring plans as a way to control this pathological problem.

  12. Prevalence of Methicillin and Vancomycin resistant Staphylococcus aureus colonization in nasopharynx; Amir-Alam hospital, 2005

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    Hasibi M

    2007-07-01

    Full Text Available Background: Staphylococcus aureus is one of the most common causes of nosocomial infections with high morbidity and mortality rate. Traditionally, methicillin resistant staphylococcus aureus has been considered a major nosocomial pathogen in healthcare facilities, but in the past decade, it has been observed emerging in the community as well. Informations regarding hospital microbial colonization could be an important step for prevention of nosocomial infections. Our objective was clarifying the prevalence of methicillin resistant and vancomycin resistant staphylococcus aureus colonization in nasopharynx. Methods: A descriptive cross sectional study was carried on 106 patients and nursing staff of surgery and hemodialysis wards in Amir-Alam hospital from April 2005 to July 2005. The samples were collected from nasal region of cases using cotton swab by two experienced technician and were sent to laboratory for culture and antibiogram. Results: Twenty six (29.5% out of 106 cases were nasopharyngeal carriers of staphylococcus aureus. Eight cases (7.5% had methicillin resistant staphylococcus aureus. The most frequent colonization rate was seen in hemodialysis nursing staff and in all of them methicillin resistant staphylococcus aureus was reported. Carrier rates in hemodialysis patients were twice compared to surgery ward patients. The interesting point was that no sample of vancomycin resistant staphylococcus aureus was isolated. Conclusion: Prevalence of methicillin resistant staphylococcus aureus colonization seems to be increased; therefore proper management for controlling this problem is mandatory. The results of the present study suggest that the prevalence of methicillin resistant staphylococcus aureus infections is higher than was expected in Iran and vigorous preventive strategies should therefore be taken to stop the growth of this major health problem.

  13. Effects of Fermented Sumach on the Formation of Slime Layer of Staphylococcus aureus

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    Sahra Kırmusaoğlu

    2012-03-01

    Full Text Available Objective: Staphylococcus aureus (S. aureus is one of the most commonly isolated bacterial pathogens in hospitals, and the most frequent cause of nosocomial infections. Nosocomial staphylococcal foreign-body infections related to biofilm formation are a serious threat, demanding new therapeutic and preventive strategies. Implantation of intravenous catheters and surgical implantation of prosthetic implants carry a risk of infection. In order to prevent all these effects of biofilms, a study was designed to observe the possible antibacterial effect of sumach (Rhus coriaria on the biofilm formation of S. aureus. Material and Methods: The influence of varying concentrations of sumach on the formation of biofilms by 13 strains of Staphylococcus aureus was tested by a microelisa assay. Results: The significant differences between varying concentrations of sumach (0.1, 0.2, 0.5 and 1.0 µl/ml were observed in four methicillin resistant Staphylococcus aureus (MRSA and nine methicillin sensitive Staphylococcus aureus (MSSA (p<0.05. In bacteria, a dose-related decrease in the formation of slime, which is a major virulence factor of staphylococcal infections, was observed. Conclusion: In our study, using 0.1, 0.2, 0.5 and 1.0 µl/ml of sumach, thirteen strains lost, 17%, 22%, 28% and 48% respectively of their capacity to produce biofilms. Sumach, which is a herbal product, can decrease the formation of biofilm, which is a major virulence factor in staphylococcal infections.

  14. Toxigenic profile of methicillin-sensitive and resistant Staphylococcus aureus isolated from special groups.

    Science.gov (United States)

    de Souza, Camila Sena Martins; Fortaleza, Carlos Magno Castelo Branco; Witzel, Claudia Lima; Silveira, Mônica; Bonesso, Mariana Fávero; Marques, Silvio Alencar; Cunha, Maria de Lourdes Ribeiro de Souza da

    2016-02-16

    Staphylococcus aureus is characterized by its pathogenicity and high prevalence, causing disease in both healthy and immunocompromised individuals due to its easy dissemination. This fact is aggravated by the widespread dissemination of S. aureus carrying toxigenic genes. The objective of this study was to determine the toxigenic profile of methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in patients with purulent skin and/or soft tissue infections seen at the Dermatology Department of the University Hospital of the Botucatu Medical School, asymptomatic adults older than 60 years living in nursing homes, and prison inmates of the Avaré Detention Center. PCR was used for the detection of the mecA gene, enterotoxin genes (sea, seb, and sec), exfoliative toxins A and B (eta and etb), toxic shock syndrome toxin 1 (tst), panton-valentine leukocidin (lukS-PV and lukF-PV), and alpha- and delta-hemolysins or cytotoxins (hla and hld). The results showed a significant prevalence of toxigenic genes among S. aureus isolates from asymptomatic individuals, with the observation of a higher prevalence of cytotoxin genes. However, the panton-valentine leukocidin gene was only detected in MSSA isolated from patients with skin infections and the tst gene was exclusively found in MSSA isolated from prison inmates. The present study demonstrated a significant prevalence of toxigenic genes in MSSA and MRSA strains isolated from asymptomatic S. aureus carriers. There was a higher prevalence of cytotoxin genes.

  15. LACTIC ACID BACTERIA WITH ANTIMICROBIAL ACTIVITY AGAINST PATHOGENIC AGENT CAUSING OF BOVINE MASTITIS BACTERIAS ACIDO LACTICAS CON ACTIVIDAD ANTIMICROBIANA CONTRA PATÓGENOS CAUSANTES DE MASTITIS BOVINA OUT BACTÉRIAS LÁTICAS COM ATIVIDADE ANTIMICROBIANA CONTRA OUT PATÓGENOS DA MASTITE BOVINA

    Directory of Open Access Journals (Sweden)

    LILIANA SERNA C

    2011-06-01

    Full Text Available The use of antibiotics to treat bovine mastitis, produces antibiotic residues in milk and decreased quality of dairy products. Lactic acid bacteria have been proposed as an alternative to avoid the use of antibiotics. This paper reports the antimicrobial activity against pathogens responsible of bovine mastitis, of 4 lactic acid strains isolated from cattle in a state of acidosis ruminal. It also evaluated the specific growth rate (m and antimicrobial activity of one of the strains, using two concentrations of carbon source (20 and 60 gl-1 in the commercial substrate MRS. The strains were biochemically identified as Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus fermen-tum and Weissella confusa. Weissella confusa showed the best antimicrobial activity against the major pathogens responsible of bovine mastitis. When has been used 60 gl-1 of total sugars in the fermentation substrate, was obtained diameter of inhibition of 31 mm for Staphylococcus aureus and 36 mm for Streptococcus agalactiae. The antimicrobial activity of Weissella confusa is superior antimicrobial activity reported by many other lactic acid bacteria, therefore Weissella confusa could potentially be used to prevent bovine mastitis.El uso de antibióticos para el tratamiento de mastitis bovina, genera residuos de antibióticos en la leche y disminuye la calidad de los subproductos lácteos. Las bacterias ácido lácticas se han propuesto como una alternativa para evitar el uso de antibióticos. En este artículo se reporta la actividad antimicrobiana contra patógenos productores de mastitis bovina, de 4 cepas acido lácticas aisladas de bovinos en estado de acidosis ruminal. Se evaluó además la velocidad especifica de crecimiento (m y la actividad antimicrobiana de una de las cepas, utilizando dos concentraciones de fuente de carbono (20 y 60 gl-1 en el sustrato comercial MRS. Las cepas se identificaron bioquímicamente como Lactobacillus acidophilus

  16. The nosocomial transmission rate of animal-associated ST398 meticillin-resistant Staphylococcus aureus

    NARCIS (Netherlands)

    Bootsma, M.C.J.; Wassenberg, M.W.M.; Trapman, J.P.; Bonten, M.J.M.

    2011-01-01

    The global epidemiology of meticillin-resistant Staphylococcus aureus (MRSA) is characterized by different clonal lineages with different epidemiological behaviour. There are pandemic hospital clones (hospital-associated (HA-)MRSA), clones mainly causing community-acquired infections

  17. The nosocomial transmission rate of animal-associated ST398 meticillin-resistant Staphylococcus aureus

    NARCIS (Netherlands)

    Bootsma, M.C.J.; Wassenberg, M.W.M.; Trapman, J.P.; Bonten, M.J.M.

    2010-01-01

    The global epidemiology of meticillin-resistant Staphylococcus aureus (MRSA) is characterized by different clonal lineages with different epidemiological behaviour. There are pandemic hospital clones (hospital-associated (HA-)MRSA), clones mainly causing community-acquired infections

  18. Eugenol reduces the expression of virulence-related exoproteins in Staphylococcus aureus.

    Science.gov (United States)

    Qiu, Jiazhang; Feng, Haihua; Lu, Jing; Xiang, Hua; Wang, Dacheng; Dong, Jing; Wang, Jianfeng; Wang, Xiaoliang; Liu, Juxiong; Deng, Xuming

    2010-09-01

    Eugenol, an essential oil component in plants, has been demonstrated to possess activity against both gram-positive and gram-negative bacteria. This study examined the influence that subinhibitory concentrations of eugenol may have on the expression of the major exotoxins produced by Staphylococcus aureus. The results from a tumor necrosis factor (TNF) release assay and a hemolysin assay indicated that S. aureus cultured with graded subinhibitory concentrations of eugenol (16 to 128 microg/ml) dose dependently decreased the TNF-inducing and hemolytic activities of culture supernatants. Western blot analysis showed that eugenol significantly reduced the production of staphylococcal enterotoxin A (SEA), SEB, and toxic shock syndrome toxin 1 (the key exotoxins to induce TNF release), as well as the expression of alpha-hemolysin (the major hemolysin to cause hemolysis). In addition, this suppression was also evaluated at the transcriptional level via real-time reverse transcription (RT)-PCR analysis. The transcriptional analysis indicated that 128 microg/ml of eugenol remarkably repressed the transcription of the S. aureus sea, seb, tst, and hla genes. According to these results, eugenol has the potential to be rationally applied on food products as a novel food antimicrobial agent both to inhibit the growth of bacteria and to suppress the production of exotoxins by S. aureus.

  19. Impacto de la resistencia a la meticilina sobre la mortalidad y vigilancia de la sensibilidad a la vancomicina en bacteriemias causadas por Staphylococcus aureus Impact of methicillin resistance on mortality and surveillance of vancomycin susceptibility in bacteremias caused by Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    F. Traverso

    2010-12-01

    Full Text Available Staphylococcus aureus es uno de los principales patógenos nosocomiales y produce una alta morbimortalidad en numerosos hospitales del mundo. Además, la incidencia de bacteriemias por este microorganismo ha aumentado significativamente en las últimas décadas. Los objetivos del presente trabajo fueron identificar los factores de riesgo que favorecen la aparición de resistencia a la meticilina en aislamientos de S. aureus y los factores que afectan la mortalidad por bacteriemias asociadas a este patógeno, así como evaluar la sensibilidad a la vancomicina de las cepas resistentes a la meticilina. Se estudiaron 39 aislamientos de S. aureus provenientes de hemocultivos de pacientes internados con bacteriemia en la Nueva Clínica Chacabuco de Tandil (Pcia. de Buenos Aires, Argentina en el período 01/2006-12/2008. La mortalidad global fue del 51,3% y estuvo significativamente asociada con la resistencia a la meticilina (OR: 4,20; IC95%: 1,08-16,32; p: 0,05; aunque dicho factor no fue un predictor independiente de mortalidad. La cirugía previa (OR: 17,23; IC95%: 1,80-164,60 y la estancia previa en la unidad de cuidados intensivos (OR: 21,12; IC95%: 2,33-191,30 fueron predictores independientes de la resistencia a la meticilina y la asistencia respiratoria mecánica (OR: 15,99; IC: 3,24-78,86 fue un predictor independiente de la mortalidad. No se detectaron cepas con sensibilidad disminuida a la vancomicina. Todos los aislamientos estudiados fueron sensibles in vitro a la vancomicina, con una CIM50 y una CIM90 de 0,5 μg/ml.Staphylococcus aureus is a major nosocomial pathogen that causes severe morbidity and mortality in many hospitals worldwide. Besides, the incidence of S. aureus bacteremia has significantly increased over the past decades. The aims of this study were to detect the risk factors for methicillin resistance and mortality and to evaluate vancomycin susceptibility in methicillin-resistant isolates. Thus, 39 S. aureus isolates from

  20. Identification of genetic determinants and enzymes involved with the amidation of glutamic acid residues in the peptidoglycan of Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Teresa A Figueiredo

    2012-01-01

    Full Text Available The glutamic acid residues of the peptidoglycan of Staphylococcus aureus and many other bacteria become amidated by an as yet unknown mechanism. In this communication we describe the identification, in the genome of S. aureus strain COL, of two co-transcribed genes, murT and gatD, which are responsible for peptidoglycan amidation. MurT and GatD have sequence similarity to substrate-binding domains in Mur ligases (MurT and to the catalytic domain in CobB/CobQ-like glutamine amidotransferases (GatD. The amidation of glutamate residues in the stem peptide of S. aureus peptidoglycan takes place in a later step than the cytoplasmic phase--presumably the lipid phase--of the biosynthesis of the S. aureus cell wall precursor. Inhibition of amidation caused reduced growth rate, reduced resistance to beta-lactam antibiotics and increased sensitivity to lysozyme which inhibited culture growth and caused degradation of the peptidoglycan.