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Sample records for aureus strains isolated

  1. Screening of Molecular Virulence Markers in Staphylococcus aureus and Pseudomonas aeruginosa Strains Isolated from Clinical Infections

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    Cotar, Ani-Ioana; Chifiriuc, Mariana-Carmen; Dinu, Sorin; Bucur, Marcela; Iordache, Carmen; Banu, Otilia; Dracea, Olguta; Larion, Cristina; Lazar, Veronica

    2010-01-01

    Staphylococcus (S.) aureus and Pseudomonas (Ps.) aeruginosa are two of the most frequently opportunistic pathogens isolated in nosocomial infections, responsible for severe infections in immunocompromised hosts. The frequent emergence of antibiotic-resistant S. aureus and Ps. aeruginosa strains has determined the development of new strategies in order to elucidate the different mechanisms used by these bacteria at different stages of the infectious process, providing the scientists with new procedures for preventing, or at least improving, the control of S. aureus and Ps. aeruginosa infections. The purpose of this study was to characterize the molecular markers of virulence in S. aureus and Ps. aeruginosa strains isolated from different clinical specimens. We used multiplex and uniplex PCR assays to detect the genes encoding different cell-wall associated and extracellular virulence factors, in order to evaluate potential associations between the presence of putative virulence genes and the outcome of infections caused by these bacteria. Our results demonstrate that all the studied S. aureus and Ps. aeruginosa strains synthesize the majority of the investigated virulence determinants, probably responsible for different types of infections. PMID:21614207

  2. Screening of Molecular Virulence Markers in Staphylococcus aureus and Pseudomonas aeruginosa Strains Isolated from Clinical Infections

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    Veronica Lazar

    2010-12-01

    Full Text Available Staphylococcus (S. aureus and Pseudomonas (Ps. aeruginosa are two of the most frequently opportunistic pathogens isolated in nosocomial infections, responsible for severe infections in immunocompromised hosts. The frequent emergence of antibiotic-resistant S. aureus and Ps. aeruginosa strains has determined the development of new strategies in order to elucidate the different mechanisms used by these bacteria at different stages of the infectious process, providing the scientists with new procedures for preventing, or at least improving, the control of S. aureus and Ps. aeruginosa infections. The purpose of this study was to characterize the molecular markers of virulence in S. aureus and Ps. aeruginosa strains isolated from different clinical specimens. We used multiplex and uniplex PCR assays to detect the genes encoding different cell-wall associated and extracellular virulence factors, in order to evaluate potential associations between the presence of putative virulence genes and the outcome of infections caused by these bacteria. Our results demonstrate that all the studied S. aureus and Ps. aeruginosa strains synthesize the majority of the investigated virulence determinants, probably responsible for different types of infections.

  3. Methicillin resistance in Staphylococcus aureus strains isolated from food and wild animal carcasses in Italy.

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    Traversa, A; Gariano, G R; Gallina, S; Bianchi, D M; Orusa, R; Domenis, L; Cavallerio, P; Fossati, L; Serra, R; Decastelli, L

    2015-12-01

    Following the detection of methicillin-resistant Staphylococcus aureus (MRSA) ST398 in food-producing animals, both livestock and wildlife, and derived products, are considered potential sources of MRSA in humans. There is a paucity of data on MRSA in foods in Italy, and the data regarding wild animals are particularly scarce. A total of 2162 food samples collected during official monitoring activities in 2008 were analyzed for the detection of S. aureus. Also, samples from 1365 wild animals collected by the National Reference Center for Wild Animal Diseases in 2003-2009 were subjected to anatomopathological examination. S. aureus isolates were processed for phenotypic and molecular methicillin resistance determinations. S. aureus was found in 2.0% of wild animal carcasses and in 3.2% of wild boar lymph nodes: none showed methicillin resistance. The prevalence of S. aureus in food was 17.1%. Two MRSA strains, both from bulk tank milk (prevalence 0.77%) were isolated: the strains were resistant to tetracycline, had spa-type t899, and were negative for the Panton-Valentine leukocidin gene. The low prevalence of MRSA suggests that the risk of transmission to humans via food is limited. However, attention should be paid to the cattle food chain, which may be a potential route of transmission of LA-MRSA.

  4. Complete genome analysis of two new bacteriophages isolated from impetigo strains of Staphylococcus aureus.

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    Botka, Tibor; Růžičková, Vladislava; Konečná, Hana; Pantůček, Roman; Rychlík, Ivan; Zdráhal, Zbyněk; Petráš, Petr; Doškař, Jiří

    2015-08-01

    Exfoliative toxin A (ETA)-coding temperate bacteriophages are leading contributors to the toxic phenotype of impetigo strains of Staphylococcus aureus. Two distinct eta gene-positive bacteriophages isolated from S. aureus strains which recently caused massive outbreaks of pemphigus neonatorum in Czech maternity hospitals were characterized. The phages, designated ϕB166 and ϕB236, were able to transfer the eta gene into a prophageless S. aureus strain which afterwards converted into an ETA producer. Complete phage genome sequences were determined, and a comparative analysis of five designed genomic regions revealed major variances between them. They differed in the genome size, number of open reading frames, genome architecture, and virion protein patterns. Their high mutual sequence similarity was detected only in the terminal regions of the genome. When compared with the so far described eta phage genomes, noticeable differences were found. Thus, both phages represent two new lineages of as yet not characterized bacteriophages of the Siphoviridae family having impact on pathogenicity of impetigo strains of S. aureus.

  5. Antibiotic resistance of Staphylococcus aureus strains isolated from fish processing factory workers

    OpenAIRE

    1988-01-01

    One hundred and twenty two strains of Staphylococcus aureus isolated from throats and palms of 39 workers from 6 fish processing factories situated in and around Cochin were tested for their sensitivity to nine commonly used antibiotics-ampicillin, chloramphenicol, erythromycin, kanamycin, neomycin, penicillin, polymyxin-B, streptomycin and tetracycline. Highest percentage of resistance was observed towards ampicillin followed by penicillin i.e. 64.75% and 59.84%. Resistance towards other ant...

  6. Major clonal lineages in impetigo Staphylococcus aureus strains isolated in Czech and Slovak maternity hospitals.

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    Růžičková, Vladislava; Pantůček, Roman; Petráš, Petr; Machová, Ivana; Kostýlková, Karla; Doškař, Jiří

    2012-11-01

    One hundred and twenty-seven exfoliative toxin-producing (ET-positive) strains of Staphylococcus aureus collected in 23 Czech and one Slovak maternity hospitals from 1998 to 2011 were genotypically characterized by multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE) profiling, spa gene polymorphism analysis, and ETA-converting prophage carriage, which resulted in the identification of 21 genotypes grouped into 4 clonal complexes (CC). Ninety-one isolates carried the eta gene alone whilst 12 isolates harboured only the etb gene. Two new, to date not defined, spa types (t6644 and t6645) and 2 novel sequence types (ST2194 and ST2195) were identified in the set of strains under study. The predominant CC121 occurred in 13 Czech hospitals. CC15, CC9, and ST88 (CC88) exclusively included eta gene-positive strains while the strains belonging to ST121 harboured the eta and/or etb genes. This study highlights not only significant genomic diversity among impetigo strains and the distribution of major genotypes disseminated in the Czech and Slovak maternity hospitals, but also reveals their impact in epidermolytic infections.

  7. In vitro susceptibility of Staphylococcus aureus strains isolated from cows with subclinical mastitis to different antimicrobial agents

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    Schlenker, Gerd; Szabo, Istvan; Roesler, Uwe

    2012-01-01

    Sensitivity to commercial teat dips (nonoxinol-9 iodine complex and chlorhexidine digluconate) of 56 Staphylococcus (S.) aureus strains isolated from quarter milk samples of various German dairy herds treated with different teat dipping schemes was investigated in this study. The minimum inhibitory concentration was determined using a broth macrodilution method according to the German Veterinary Association guidelines. The main objective of the current study was to induce in vitro resistance induction of S. aureus to chemical disinfectants. Ten different strains were repeatedly passed ten times in growth media with sub-lethal concentrations of disinfectants. Nine strains showed a significant reduction in susceptibility to the nonoxinol-9 iodine complex but only one strain developed resistance to chlorhexidine digluconate. Stability of the acquired resistance was observed in all S. aureus strains adapted to the nonoxinol-9 iodine complex and chlorhexidine digluconate. In contrast, simultaneous resistance to different antibiotics was not observed in any of the ten investigated S. aureus strains. However, the isolates exhibited a high degree of resistance to penicillin G. Based on these results, resistance of S. aureus to chemical disinfectants may be more likely to develop if the chemicals are used at concentrations lower than that required for an optimal biocidal effect. PMID:22705737

  8. Eugenol Provokes ROS-Mediated Membrane Damage-Associated Antibacterial Activity Against Clinically Isolated Multidrug-Resistant Staphylococcus aureus Strains.

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    Das, Balaram; Mandal, Debasis; Dash, Sandeep Kumar; Chattopadhyay, Sourav; Tripathy, Satyajit; Dolai, Durga Pada; Dey, Sankar Kumar; Roy, Somenath

    2016-01-01

    Due to the indiscriminate use of antibiotics, resistance to antibiotics has increased remarkably in Staphylococcus aureus. Vancomycin is the final drug to treat the S. aureus infection, but nowadays, resistance to this antibiotic is also increasing. So, the investigation of antibiotic resistance pattern is important. As there is already resistance to vancomycin, there is an urgent need to develop a new kind of antimicrobial to treat S. aureus infection. Eugenol may be the new drug of choice. This study was conducted to evaluate the antibacterial activity of eugenol against vancomycin-resistant S. aureus isolated from clinical pus samples. Thirty six pus samples were included in the study. Samples were isolated, identified and antimicrobial susceptibility tests were performed as per routine laboratory protocol. The antimicrobial activity and mechanisms of killing of eugenol were studied. Out of 36 pus samples, only 20 isolates were confirmed as S. aureus strains and 6 isolates exhibited vancomycin resistance. Eugenol successfully destroyed the vancomycin-resistant strains via reactive oxygen species generation and membrane damage. The prevalence of vancomycin resistance is increased day by day in different countries, and necessary steps to prevent the spread and emergence of resistance should be taken. The findings of the study suggested that eugenol might be used to treat vancomycin-resistant S. aureus.

  9. [Investigation of the presence of panton-valentin leucocidin (PVL) in Staphylococcus aureus strains isolated from clinical samples].

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    Ozkul, Hilal; Oktem, I M Ali; Gülay, Zeynep

    2007-07-01

    Panton-Valentin leucocidin (PVL) is a cytotoxin which causes tissue necrosis by degradating leucocytes and other cell types. PVL has recently become very up to date as it has been shown to be the major virulance factor of community acquired methicillin resistant Staphylococcus aureus strains. In this study, the presence of PVL was investigated in methicillin sensitive and resistant S. aureus (MSSA and MRSA, respectively) strains which were isolated from clinical samples between January 2005-May 2006 at Dokuz Eylul University Hospital, Izmir. Fifty five MRSA and 79 MSSA strains which were isolated from blood, wound and respiratory tract samples were randomly included to the study. The presence of PVL was evaluated by multiplex polymerase chain reaction (PCR) which detects pvl and S. aureus-specific nuc genes. As a result, PVL positivities were detected in two (5%) of 40 MSSA and four (10.3%) of 39 MSSA strains isolated in the years 2005 and 2006, respectively. None of the MRSA isolates had pvl gene. Although this cytotoxin was rarely detected among MSSA isolates, it was interesting to note that the prevalence of PVL was twice more in the year 2006 compared to 2005. It was also worth to notify that four of six (66.7%) PVL positive strains had been isolated from the patients of general surgery inpatient or outpatient clinics.

  10. Prevalence, molecular characterization of Staphylococcus aureus isolated from cheese and in vitro antibacterial activity of silver nanoparticles against such strains

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    Karima G. Abdel Hameed

    2015-07-01

    Full Text Available Aim: The aim was to investigate cheese samples for the prevalence of Staphylococcus aureus, evaluate multiplex polymerase chain reaction (PCR methods for S. aureus identification, as well as to determine the antibacterial activity of silver nanoparticles against such strains. Materials and Methods: Total of 100 random locally manufactured cheese samples were collected from Qena dairy markets, Egypt, and examined conventionally for the prevalence of S. aureus then, confirmation of these isolates were done using multiplex PCR. The antibacterial activity of silver nanoparticles against such isolates was also checked. Results: Lower prevalence of S. aureus in Damietta cheese (54% than in Kareish cheese (62% was recorded. As well lower frequency distribution for both S. aureus (36% and CNS (8% was also reported for Damietta cheese. Using of multiplex PCR method for S. aureus identification have been confirmed all 58 S. aureus stains that were identified conventionally by detection of two PCR products on agarose gel: The 791 bp and the 638 bp. The correlation coefficient between conventional and multiplex PCR method was 0.91 and was significant at p≤0.001. Regarding antibacterial activity of silver nanoparticles using disk diffusion method on Baird Parker agar it was found that inhibition zone of silver nanoparticles against S. aureus, was 19.2±0.91 mm and it was higher than that produced by gentamicin (400 units/ml 15.2±0.89 mm. Conclusions: The present study illustrated the higher prevalence of S. aureus in cheese samples that may constitute a public health hazard to consumers. According to the results, it can be concluded that silver nanoparticles can be used as an effective antibacterial against S. aureus. Thereby, there is a need for an appropriate study for using silver nanoparticles in cleaning and disinfection of equipment and in food packaging.

  11. Comparison of antimicrobial resistance in Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes strains isolated from organic and conventional poultry meat.

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    Miranda, J M; Vázquez, B I; Fente, C A; Calo-Mata, P; Cepeda, A; Franco, C M

    2008-12-01

    The presence of Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes was determined in 55 samples of organic poultry meat and in 61 samples of conventional poultry meat. A total of 220 E. coli, 192 S. aureus, and 71 L. monocytogenes strains were analyzed by an agar disk diffusion assay for their resistance to ampicillin, cephalothin, chloramphenicol, ciprofloxacin, doxycycline, fosfomycin, gentamicin, nitrofurantoin, streptomycin, and sulfisoxazole (E. coli); chloramphenicol, ciprofloxacin, clindamycin, doxycycline, erythromycin, gentamicin, nitrofurantoin, oxacillin, and sulfisoxazole (S. aureus); and chloramphenicol, doxycycline, erythromycin, gentamicin, sulfisoxazole, and vancomycin (L. monocytogenes). The results indicated a significantly higher (P poultry meat as compared with conventional poultry meat. E. coli isolated from organic poultry meat exhibited lower levels of antimicrobial resistance against 7 of the 10 antimicrobials tested as compared with isolates recovered from conventional meat. In the case of S. aureus and L. monocytogenes isolated from conventional poultry, antimicrobial resistance was significantly higher only for doxycycline as compared with strains isolated from organic poultry. In the case of E. coli, the presence of multiresistant strains was significantly higher (P poultry meat as compared with organic poultry meat. Organically farmed poultry samples showed significantly lower development of antimicrobial resistance in intestinal bacteria such as E. coli.

  12. Isolation, Virulence, and Antimicrobial Resistance of Methicillin-Resistant Staphylococcus aureus (MRSA) and Methicillin Sensitive Staphylococcus aureus (MSSA) Strains from Oklahoma Retail Poultry Meats.

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    Abdalrahman, Lubna S; Stanley, Adriana; Wells, Harrington; Fakhr, Mohamed K

    2015-05-29

    Staphylococcus aureus is one the top five pathogens causing domestically acquired foodborne illness in the U.S. Only a few studies are available related to the prevalence of S. aureus and MRSA in the U.S. retail poultry industry. The objectives of this study were to determine the prevalence of S. aureus (MSSA and MRSA) in retail chicken and turkey meats sold in Tulsa, Oklahoma and to characterize the recovered strains for their antimicrobial resistance and possession of toxin genes. A total of 167 (114 chicken and 53 turkey) retail poultry samples were used in this study. The chicken samples included 61 organic samples while the rest of the poultry samples were conventional. The overall prevalence of S. aureus was 57/106 (53.8%) in the conventional poultry samples and 25/61 (41%) in the organic ones. Prevalence in the turkey samples (64.2%) was higher than in the chicken ones (42.1%). Prevalence of S. aureus did not vary much between conventional (43.4%) and organic chicken samples (41%). Two chicken samples 2/114 (1.8%) were positive for MRSA. PFGE identified the two MRSA isolates as belonging to PFGE type USA300 (from conventional chicken) and USA 500 (from organic chicken) which are community acquired CA-MRSA suggesting a human based source of contamination. MLST and spa typing also supported this conclusion. A total of 168 Staphylococcus aureus isolates (101 chicken isolates and 67 turkey isolates) were screened for their antimicrobial susceptibility against 16 antimicrobials and their possession of 18 different toxin genes. Multidrug resistance was higher in the turkey isolates compared to the chicken ones and the percentage of resistance to most of the antimicrobials tested was also higher among the turkey isolates. The hemolysin hla and hld genes, enterotoxins seg and sei, and leucocidins lukE-lukD were more prevalent in the chicken isolates. The PVL gene lukS-lukF was detected only in chicken isolates including the MRSA ones. In conclusion, S. aureus is

  13. Staphylococcal food poisoning case and molecular analysis of toxin genes in Staphylococcus aureus strains isolated from food in Sicily, Italy.

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    Vitale, Maria; Scatassa, Maria Luisa; Cardamone, Cinzia; Oliveri, Giuseppa; Piraino, Chiara; Alduina, Rosa; Napoli, Concetta

    2015-01-01

    A case of staphylococcal food poisoning was observed in two individuals of the same family after consumption of primosale, a semiripened sheep cheese produced in Sicily. Staphylococcus aureus isolated from the cheese produced enterotoxin C (SEC) and carried both the enterotoxin C (sec) and the toxic shock syndrome toxin (tsst-1) gene. Following this case, an extensive survey was conducted on 971 food samples (raw milk, cheese, meat, and food preparations). S. aureus was detected in 102 of 971 food samples, from all types of food with the exception of ricotta cheese. The tsst-1 gene was present in 42% of the strains, either alone or in combination with other toxin genes. The enterotoxin C gene was the most represented enterotoxin, but it was only found in dairy products. Six S. aureus isolates carried the sea gene alone, two isolates carried both sea and seb, and one isolate carried both sea and sec. A significant percentage (46%) of all isolates carried a toxin gene, creating significant concern that virulent S. aureus can be transmitted through food in Sicily.

  14. Occurrence, Virulence Factors, Antimicrobial Resistance, and Genotyping of Staphylococcus aureus Strains Isolated from Chicken Products and Humans.

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    El Bayomi, Rasha M; Ahmed, Heba A; Awadallah, Maysa A I; Mohsen, Rasha A; Abd El-Ghafar, Abeer E; Abdelrahman, Mahmoud A

    2016-03-01

    Staphylococcus aureus in food is a consequence of inadequate hygienic handling and processing, posing a potential risk to public health. The current study aimed to characterize virulence factors, as well as antimicrobial resistance of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) isolated from retail chicken products and hand swabs from vendors in Egypt. In addition, genetic relatedness of the isolates from chicken and humans was evaluated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using protein A as a target. A total of 110 samples were collected from chicken products (n = 80) and vendors (n = 30). Overall, 30 (37.5%) chicken products samples were positive for S. aureus, whereas hand swabs from meat handlers revealed that 18 (60%) were positive. Ten MRSA strains were characterized by the presence of the mecA gene, comprising seven isolates from chicken and three from humans. Virulence-associated factors were evaluated by PCR, revealing that 31.3% of S. aureus isolates harbored the Panton-Valentine leukocidin (PVL) gene, whereas 10.4% were positive for the sea and sed genes each, and only two isolates were positive for γ-hemolysin-associated gene. Genotyping using spa PCR-RFLP showed identical restriction banding patterns of MRSA isolates of human and chicken meat origin, indicating the genetic relatedness of the isolates. To the best of our knowledge, this is the first study to characterize PVL-positive MRSA from chicken products and to utilize spa-RFLP for evaluating the genetic relatedness between MRSA of human and chicken origin in Egypt.

  15. Synergistic effects of plant extracts and antibiotics on Staphy-lococcus aureus strains isolated from clinical specimens

    Institute of Scientific and Technical Information of China (English)

    Ghaleb Adwan; Mohammad Mhanna

    2009-01-01

    Objective:This study has been done to evaluate the interaction between water extracts of Psidium guajava, Rosmarinus officinalis,Salvia fruticosa,Majorana syriaca,Ocimum basilucum,Syzygium aromaticum,Laurus nobilis,and Rosa damascena alone and then synergy testing of these extracts with known antimicrobial agents including oxytetracycline HCl,gentamicin sulfate,penicillin G,cephalexin and enrofloxacin.This study was conducted against five S.aureus isolates;one is Methicillin -resistant Staphylococcus aureus (MRSA)and 4 Methicillin -sensitive Staphylococcus aureus (MSSA).Methods:Evaluation of the interaction between plant extracts and different antimicrobial agents has been done using well -diffusion and microdilution methods. Results:The results of the conducted experiments using well -diffusion method demonstrate that these plants showed in vitro interactions between antimicrobial agents and plant extracts were additive,while using microdi-lution method showed synergistic effects with significant reduction in the MICs of the test antibiotics against these strains of S.aureus.This change in MIC was noticed in all plant extracts against test antibiotics inclu-ding these plants showed weak antibacterial activity by well diffusion method.Synergism effect was occurred in both sensitive and resistant strains but the magnitude of minimum fold reduction of inhibitory concentration in resistant strains especially MRSA strain was higher than the sensitive strains.Coclusion:This study probably suggests the possibility of concurrent use of these antimicrobial drugs and plant extracts in combination in trea-ting infections caused by S.aureus strains or at least the concomitant administration may not impair the antimi-crobial activity of these antibiotics.

  16. Expression of enterotoxin-coding genes in methicillin-resistant Staphylococcus aureus strains isolated from Mexican haemodialysis patients

    OpenAIRE

    Paniagua-Contreras, Gloria Luz; Monroy-Pérez, Eric; Vaca-Paniagua, Felipe; RODRÍGUEZ-MOCTEZUMA,JOSÉ RAYMUNDO; Vaca, Sergio

    2014-01-01

    Background Methicillin-resistant Staphylococcus aureus (MRSA) causes severe catheter-related infections in haemodialysis patients ranging from local-site infections and septic thrombophlebitis to bacteraemia but the associated virulence factors and exotoxins remain unclear. Findings We employed an in vitro infection model using reconstituted human epithelium (RHE) to analyse the expression profiles of 4 virulence genes and 12 exotoxin-coding virulence genes in 21 MRSA strains isolated from ca...

  17. Phage type and sensitivity to antibiotics of Staphylococcus aureus film-forming strains isolated from airway mucosa

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    O. S. Voronkova

    2014-10-01

    Full Text Available Today film-forming strains of bacteria play very important role in clinical pathology. Staphylococci are ones of most dangerous of them. This bacteria can determine different pathological processes, for example, complication of airway mucosa. The ability to form a biofilm is one of the main properties of nosocomial strains. These strains should be monitored and their carriers are to be properly treated. To determine the origin of staphylococci strains we used bacteriophages from the International kit. The aim of research was to determine the phage type of staphylococci film-forming strains, that were isolated from naso-pharingial mucosa. Phage typing has been carried out for 16 film-forming strains of S. aureus. To solve this problem, we used the International phage kit by Fisher’s method. As a result, sensitivity to phages from the International kit showed 53.8% of studied strains of S. aureus. 64.3% of sensitivity strains were lysed by one of the phage, 21.4% – were by two of the phages, 14.3% – by three of the phages. Isolates were sensitive to phages: 81 – 42.9%, 75 – 35.7%, 28.6% were sensitive to phages 47 and 53. All cases of detection of sensitivity to phage 47 coincided with the ability to form biofilm. Among non-film-forming strains there was no sensitive strains for this phage. Film-forming strains resist to erythromycin (62.5%, ciprofloxacin (43.8%, gentamicin (56.3%, tetracycline (87.5%, amoxicillin (93.8%, and cefuroxime (37.5%. All cases of sensitivity to phage 47 coincided with resistance to erythromycin, amoxicillin and tetracycline. For two of these strains, we also defined resistance to gentamicin and for one of them – to ciprofloxacin. Results of research allowed to relate the bacterial cultures for determining the type. This may have implications for studying of film-forming ability, because surface structures of bacterial cell take place in this process. Belonging of an isolate to specific phage type may

  18. Spa Typing of Staphylococcus aureus Strains Isolated From Clinical Specimens of Patients With Nosocomial Infections in Tehran, Iran

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    Goudarzi, Mehdi; Fazeli, Maryam; Goudarzi, Hossein; Azad, Mehdi; Seyedjavadi, Sima Sadat

    2016-01-01

    Background The incidence of nosocomial Staphylococcus aureus infection is increasing annually and becoming a true global challenge. The pattern of Staphylococcus aureus protein A (spa) types in different geographic regions is diverse. Objectives This study determined the prevalence of methicillin-resistant S. aureus and different spa types in S. aureus clinical isolates. Materials and Methods During a six-month period, 90 S. aureus isolates were recovered from 320 clinical specimens. The in vitro susceptibility of various S. aureus isolates to 16 antibiotic discs was assessed using the Kirby-Bauer disk diffusion method. Molecular typing was carried out with S. aureus protein A typing via polymerase chain reaction. Results The frequency of methicillin-resistant S. aureus in our study was 88.9%. Twenty-three (25.5%) isolates were positive for panton-valentine leukocidin encoding genes. S. aureus presented a high resistance rate to ampicillin (100%) and penicillin (100%). No resistance was observed to vancomycin, teicoplanin, or linezolid. The rates of resistance to the majority of antibiotics tested varied between 23.3% and 82.2%. The rate of multidrug resistance among these clinical isolates was 93.3%. The 90 S. aureus isolates were classified into five S. aureus protein A types: t037 (33.3%), t030 (22.2%), t790 (16.7%), t969 (11.1%), and t044 (7.7%). Eight (8.9%) isolates were not typable using the S. aureus protein A typing method. Conclusions We report a high methicillin-resistant S. aureus rate in our hospital. Additionally, t030 and t037 were the predominant spa-types among hospital-associated S. aureus. Our findings emphasize the need for continuous surveillance to prevent the dissemination of multidrug resistance among different S. aureus protein A types in Iran. PMID:27679706

  19. Short communication: Lipolytic activity on milk fat by Staphylococcus aureus and Streptococcus agalactiae strains commonly isolated in Swedish dairy herds.

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    Vidanarachchi, Janak K; Li, Shengjie; Lundh, Åse Sternesjö; Johansson, Monika

    2015-12-01

    The objective of this study was to determine the lipolytic activity on milk fat of 2 bovine mastitis pathogens, that is, Staphylococcus aureus and Streptococcus agalactiae. The lipolytic activity was determined by 2 different techniques, that is, thin-layer chromatography and an extraction-titration method, in an experimental model using the most commonly occurring field strains of the 2 mastitic bacteria isolated from Swedish dairy farms. The microorganisms were inoculated into bacteria-free control milk and incubated at 37°C to reflect physiological temperatures in the mammary gland. Levels of free fatty acids (FFA) were analyzed at time of inoculation (t=0) and after 2 and 6h of incubation, showing significant increase in FFA levels. After 2h the FFA content had increased by approximately 40% in milk samples inoculated with Staph. aureus and Strep. agalactiae, and at 6h the pathogens had increased FFA levels by 47% compared with the bacteria-free control milk. Changes in lipid composition compared with the bacteria-free control were investigated at 2 and 6h of incubation. Diacylglycerols, triacylglycerols, and phospholipids increased significantly after 6h incubation with the mastitis bacteria, whereas cholesterol and sterol esters decreased. Our results suggest that during mammary infections with Staph. aureus and Strep. agalactiae, the action of lipases originating from the mastitis pathogens will contribute significantly to milk fat lipolysis and thus to raw milk deterioration.

  20. Characterization of Staphylococcus aureus strains isolated from faeces of healthy neonates and potential mother-to-infant microbial transmission through breastfeeding.

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    Benito, Daniel; Lozano, Carmen; Jiménez, Esther; Albújar, Mar; Gómez, Adolfo; Rodríguez, Juan M; Torres, Carmen

    2015-03-01

    Twenty-one women and their respective singleton infants participated in this study, contributing with samples of breast milk and faeces (at days 7, 14 and 35 after birth), respectively, used for Staphylococcus aureus recovery. The aim was to track the carriage of S. aureus in milk and infant faeces of mother-infant pairs, and to determine the genetic lineages of the isolates, their potential clonal relationships and their content in antimicrobial resistance, virulence and immune evasion cluster genes. The molecular characterization was performed by PCR and sequencing. Clonal relationship among mother-infant isolates was conducted by spa typing, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Staphylococcus aureus was isolated from milk samples of 6 of 21 mothers (16 isolates) and from faecal samples of 12 of 21 infants (25 isolates). From these 41 S. aureus recovered, 18 were methicillin-resistant (MRSA) and 23 methicillin-susceptible (MSSA). Twelve diferentes spa types and eight sequence types were detected among S. aureus. Predominant clonal complexes were CC5 (43.9%) and CC30 (36.6%). MRSA strains presented a multidrug-resistance profile, 65.2% of MSSA strains harboured tsst-1 toxin gene and 26.8% of total strains carried the cna gene. A potential mother-to-infant S. aureus transmission was demonstrated in four cases by spa typing, MLST and PFGE (transmission of t322/ST5/CC5-PFGE-A, t136/ST34/CC30-PFGE-B and t021/ST1869/CC30-PFGE-C strains). Breastfeeding seems to contribute to early S. aureus intestinal colonization in neonates what might affect the immune system development.

  1. 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.

  2. Molecular study on methicillin-resistant Staphylococcus aureus strains isolated from dogs and associated personnel in Jordan

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    Yaser; Hamadeh; Tarazi; Ahmed; Mahmoud; Almajali; Mustafa; Mohammad; Kheer; Ababneh; Humam; Shawket; Ahmed; Adnan; Saleem; Jaran

    2015-01-01

    Objective: To determine the prevalence, genetic relatedness, and pattern of antimicrobial susceptibility in methicillin-resistant Staphylococcus aureus(S. aureus)(MRSA) isolated from household dogs, farm dogs, and stray dogs, compared to isolates from their associated personnel.Methods: MRSA was isolated from 250 nasal swabs(150 swabs from dogs and 100 swabs from humans). PCR assays were used to detect the presence of both the nuc and mec A genes,which con firmed the identity of S. aureus isolates and the presence of methicillin resistance,respectively. Disk diffusion was used to determine the antibiotic susceptibility against 15 antimicrobial agents along with an E-test that determined the minimum inhibitory concentration for oxacillin. Pulsed field gel electrophoresis was conducted to determine the genetic relatedness of MRSA isolates from dogs to those from associated and unassociated personnel.Results: The prevalence of S. aureus in dogs and humans was 12.7% and 10.0%respectively, while the prevalence of MRSA isolates in dogs and humans was 5.3% and5.0%, respectively. The prevalence of MRSA isolates in household dogs, farm dogs, and stray dogs was 7.8%, 4.7%, and 0.0%, respectively. MRSA isolates demonstrated a significantly higher rate of multi-resistance against three or more antimicrobial agents than methicillin-susceptible S. aureus(MSSA). Trimethoprim-sulphamethoxazole and chloramphenicol were the most effective antibiotics against all MRSA isolates. Pulsed field gel electrophoresis revealed a strong association between dog MRSA isolates and MRSA isolates from strongly associated personnel.Conclusions: MRSA is prevalent in house dogs, as well as in dog rearing centers and among their strongly associated personnel. A strong association was found between the MRSA isolates from dogs and those from humans who are in close contact. In addition,MRSA isolates showed a high rate of multi-resistance compared to MSSA isolates.

  3. Molecular study on methicillin-resistant Staphylococcus aureus strains isolated from dogs and associated personnel in Jordan

    Institute of Scientific and Technical Information of China (English)

    Yaser Hamadeh Tarazi; Ahmed Mahmoud Almajali; Mustafa Mohammad Kheer Ababneh; Humam Shawket Ahmed; Adnan Saleem Jaran

    2015-01-01

    Objective:To determine the prevalence, genetic relatedness, and pattern of antimicrobial susceptibility in methicillin-resistant Staphylococcus aureus (S. aureus) (MRSA) isolated from household dogs, farm dogs, and stray dogs, compared to isolates from their associated personnel. Methods: MRSA was isolated from 250 nasal swabs (150 swabs from dogs and 100 swabs from humans). PCR assays were used to detect the presence of both the nuc and mecA genes, which confirmed the identity of S. aureus isolates and the presence of methicillin resistance, respectively. Disk diffusion was used to determine the antibiotic susceptibility against 15 antimicrobial agents along with an E-test that determined the minimum inhibitory concentration for oxacillin. Pulsed field gel electrophoresis was conducted to determine the genetic relatedness of MRSA isolates from dogs to those from associated and unassociated personnel. Results:The prevalence of S. aureus in dogs and humans was 12.7%and 10.0%respectively, while the prevalence of MRSA isolates in dogs and humans was 5.3%and 5.0%, respectively. The prevalence of MRSA isolates in household dogs, farm dogs, and stray dogs was 7.8%, 4.7%, and 0.0%, respectively. MRSA isolates demonstrated a significantly higher rate of multi-resistance against three or more antimicrobial agents than methicillin-susceptible S. aureus (MSSA). Trimethoprim-sulphamethoxazole and chloramphenicol were the most effective antibiotics against all MRSA isolates. Pulsed field gel electrophoresis revealed a strong association between dog MRSA isolates and MRSA isolates from strongly associated personnel. Conclusions:MRSA is prevalent in house dogs, as well as in dog rearing centers and among their strongly associated personnel. A strong association was found between the MRSA isolates from dogs and those from humans who are in close contact. In addition, MRSA isolates showed a high rate of multi-resistance compared to MSSA isolates.

  4. Frequency of resistance to methicillin and other antimicrobial agents among Staphylococcus aureus strains isolated from pigs and their human handlers in Trinidad

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    Annika Gordon

    2014-04-01

    Full Text Available Background: Methicillin-resistant Staphylococcus aureus (MRSA has emerged recently worldwide in production animals, particularly pigs and veal calves, which act as reservoirs for MRSA strains for human infection. The study determined the prevalence of MRSA and other resistant strains of S. aureus isolated from the anterior nares of pigs and human handlers on pig farms in Trinidad. Methods: Isolation of S. aureus was done by concurrently inoculating Baird-Parker agar (BPA and Chromagar MRSA (CHROM with swab samples and isolates were identified using standard methods. Suspect MRSA isolates from Chromagar and BPA were subjected to confirmatory test using Oxoid PBP2 latex agglutination test. The disc diffusion method was used to determine resistance to antimicrobial agents. Results: The frequency of isolation of MRSA was 2.1% (15 of 723 for pigs but 0.0% (0 of 72 for humans. Generally, for isolates of S. aureus from humans there was a high frequency of resistance compared with those from pigs, which had moderate resistance to the following antimicrobials: penicillin G (54.5%, 51.5%, ampicillin (59.1%, 49.5%, and streptomycin (59.1%, 37.1%, respectively. There was moderate resistance to tetracycline (36.4%, 41.2% and gentamycin (27.2%, 23.7% for human and pig S. aureus isolates, respectively, and low resistance to sulfamethoxazole-trimethoprim (4.5%, 6.2% and norfloxacin (9.1%, 12.4%, respectively. The frequency of resistance to oxacillin by the disc method was 36.4 and 34.0% from S. aureus isolates from humans and pigs, respectively. Out of a total of 78 isolates of S. aureus from both human and pig sources that were resistant to oxacillin by the disc diffusion method, only 15 (19.2% were confirmed as MRSA by the PBP'2 latex test kit. Conclusions: The detection of MRSA strains in pigs, albeit at a low frequency, coupled with a high frequency of resistance to commonly used antimicrobial agents in pig and humans could have zoonotic and therapeutic

  5. Frequency and Antibiotic Resistance Pattern in Staphylococcus aureus Strains Isolated from Clinical Samples of Tehran’s Araad Hospital in 2007-2011

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    Hamed Molaabaszadeh

    2014-01-01

    Full Text Available ABSTRACT Background and objective: Todays, the resistance to antibiotics among of pathogen bacteria is one of the main concerns of doctors all around the world, with consideration to different reports about Staphylococcus aureus bacteria’s sensitivity, this study was done to examine the pattern of sensitivity and antibiotic resistance of Staphylococcus aureus strains collected from clinical samples of patients hospitalized in Tehran’s Araad hospital. Materials and methods: In this descriptive examination, after extracting Staphylococcus aureus derivations from clinical samples (urine, catheter, phlegm, wound, bronchial and blood, their sensitivity was measured using standard Kirby-Bauer test, in contract with following antibiotics Amikacin, Ciprofloxacin, Vancomycin, Imipenem, Sulfametoxazole Trimetoprime, Tetracycline, Oxacillin, Ceftriaxone and Penicillin. Results: In this study 260 samples of Staphylococcus aureus isolated from clinical specimens in three years. The most sensivity was to Vancomycin and the most resistance was to Penicillin and Oxacillin. Conclusion: The results of this study are indicating that Staphylococcus aureus strains resistance has increased against Penicillin and Oxacillin; presumably it is due to excessive consumption of these antibiotics. It is obvious that, with regard to increasing consumption of antibiotics and consequently, augmentation of antibacterial resistance, control of this resistance factor is necessary and inevitable, so it is recommended to avoid unnecessary usage of antibiotics.

  6. Impact of psm-mec in Methicillin-Resistant Staphylococcus aureus (ST764) Strains Isolated from Keratitis Patients.

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    Suzuki, Takashi; Yamamoto, Toshihiro; Kaito, Chikara; Miyamoto, Hitoshi; Ohashi, Yuichi

    2016-10-01

    Staphylococcus aureus is a predominant pathogen in keratitis, and the rate of methicillin-resistant S. aureus (MRSA) is increasing. In our previous study, genotypes of MRSA isolates from keratitis cases were classified into ST5 or ST764 lineage by multi-locus sequence typing. In this study, we examined the virulence properties of these MRSA keratitis isolates and its virulence determinants. There was no difference in the prevalence of virulence genes, such as adhesion and toxins, between ST5 and ST764 isolates. All ST5 isolates carried the intact psm-mec gene, which suppresses exotoxin production and colony spreading, but promotes biofilm formation. In contrast, all ST764 isolates had one point mutation in the psm-mec gene. Biofilm production in ST5 isolates was significantly higher than that in ST764 isolates, whereas colony spreading, hemolytic activity, and production of alpha-phenol-soluble modulins were higher in ST764 than in ST5 isolates. The toxicity of ST764 supernatants to corneal epithelial cells was higher than that of ST5 supernatants. These results suggest that the point mutation in the psm-mec gene contributes to the difference in virulence properties between ST5 and ST764 isolates in MRSA keratitis.

  7. The Prevalence of Resistance to Methicillin in Staphylococcus aureus Strains Isolated from Patients by PCR Method for Detec-tion of mecA and nuc Genes.

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    Roxana Sahebnasagh

    2014-01-01

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA is the main cause of hospital infection emerged over the last decades. Rapid detection of MRSA is important for patient care and proper usage of infection control. Detection of mecA genes (encoding resistance to methicillin and other similar antibiotics and nuc genes (encoding staphylococcal thermostable nuclease by PCR method is now considered for rapid identification of MRSA strain. The aim of this study was to determine the prevalence of MRSA isolated from patients in Tehran, Iran by PCR method for detection of mecA and nuc genes.Phenotypic method such as microscopic and colony morphology and catalase and coagulase tests were used for identification of S. aureus isolates. DNA was extracted from all isolates and the presence of nuc and mecA gene was detected by PCR method. For determination of MRSA by phenotypic methods, oxacillin disk diffusion test were used. Data were analyzed by SPSS software.Out of 126 clinical sample identified by phenotypic method, 101 isolates had nuc gene. In disk diffusion tests by oxacillin disk, 78.2% of isolates were considered to be MRSA, but in PCR method for mecA gene, 69% isolates were positive.The results showed a high prevalence of methicillin-resistance among S. aureus isolates. Identifying MRSA strains, isolating MRSA-positive patients and carrier's treatment in a hospital to prevent MRSA infection is important in limiting the spread of MRSA. The PCR method for detection of nuc and mecA genes has potential for rapid and accurate diagnosis of MRSA strains.

  8. Biofilm production and presence of ica and bap genes in Staphylococcus aureus strains isolated from cows with mastitis in the eastern Poland.

    Science.gov (United States)

    Szweda, Piotr; Schielmann, Marta; Milewski, Sławomir; Frankowska, Aneta; Jakubczak, Antoni

    2012-01-01

    The aim of the study was phenotypic and genotypic analysis of 132 S. aureus strains isolated from mastitis in eastern Poland in respect to their biofilm formation ability. The analysis of the size polymorphism of fragment X in the gene encoding protein A (spa) revealed high genetic differentiation of the analyzed group of isolates. The ability of biofilm formation by the isolates was tested using two phenotypic methods. The Congo Red plate assay was found to be irreproducible and very subjective. More objective results were obtained using the spectrophotometric, microtiter plate assay. Most of the isolates, namely 76/132 (57.6 %) were classified as biofilm producers depending on the value of absorbance in the microtiter plate test. All of the isolates tested were found to possess both icaA and icaD genes, while the bap gene was absent in all strains.

  9. Prevalence of Panton-Valentine leucocidin and phenotypic and genotypic characterization of biofilm formation among Staphylococcus aureus strains isolated from children with adenoid hypertrophy.

    Science.gov (United States)

    Emaneini, Mohammad; Khoramrooz, Seyed Sajjad; Shahsavan, Shadi; Dabiri, Hossein; Jabalameli, Fereshteh

    2015-12-01

    Adenoids as a first line of host defense against respiratory microbes play an important role in majority of upper airway infectious and noninfectious illnesses. Bacterial pathogen can colonize on the adenoid tissue and probably act as a reservoir for them. To determine phenotypic and genotypic characterization of biofilm forming capacity of Staphylococcus aureus isolates from children with adenoid hypertrophy and prevalence of Panton-Valentine leukocidin (PVL) gene we collected 17 consecutive, clinically significant S. aureus isolates from children with adenoid hypertrophy undergoing adenoidectomy with one or more of the upper airway obstruction symptoms, nasal obstruction, mouth breathing, snoring, or sleep apnea. Biofilm formation was evaluated by colorimetric microtiter plate's assay. Gene encoding PVL and adhesion- or biofilm formation-encoding genes were targeted by polymerase chain reaction (PCR) assay. According to the results, all strains produced biofilm. Seven (41.2%) isolates produced strong biofilm whereas 7 (41.2%) isolates produced week and 3 (17.6%) isolates produced medium biofilm. Regarding the adhesion- or biofilm formation-encoding genes, 16 (94.1%) isolates were positive for the gene eno, 13(76.4%) for icaA, 13 (76.4%) for icaD, 10 (58.8%) for fib, 10 (58.8%) for fnbB, 4(23.5%) for can, and 1(5.8%) for fnbA. The high prevalence of genes encoding biofilms and adhesins and phenotypic ability to form a biofilm by S. aureus strains emphasizes the pathogenic character of strains isolated from children with adenoid hypertrophy.

  10. METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS STRAINS IN FOOD AND ANIMAL

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    A. Traversa

    2010-03-01

    Full Text Available Some authors reported the possibility of a methicillin-resistant Staphylococcus aureus (MRSA human infections from meat and dairy products and methicillin-resistant Staphylococcus intermedius isolation in animals. The aim of this study is to investigate the methicillin-resistance in S. aureus strains and in S. intermedius strains (food and wild animals. 236 S.aureus strains from food, 36 S.aureus strains and 1 S. intermedius strain from wild animals were analyzed. 2 (0.74% MRSA strains from bovine milk were phenotipically resistant to cefoxitin, grew on chromogenic medium (MRSA Brilliance Oxoid and were mecA positive. All MRSA strains had the spa-type t899. All mecA positive strains showed at least resistance to eight of the antibiotics tested but none to glicopeptides. Both MRSA strains were enterotoxigenic.

  11. Multiple drug resistant Staphylococcus aureus strains isolated from a fish market and from fish handlers Multiresistência a antimicrobianos de cepas de Staphylococcus aureus isoladas de uma feira de pescado e de seus manipuladores

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    W.F. Albuquerque

    2007-03-01

    Full Text Available The aim of this study was to investigate the presence of antibiotic resistant Staphylococcus aureus strains in fish stalls and in hands and nasal and oral cavities of fish handlers of the Mucuripe Fish Market, Fortaleza, Ceará, Brazil. All S. aureus isolates were resistant to Ampicillin and 44 % were multi-drug resistant.O objetivo da pesquisa foi investigar a presença de Staphylococcus aureus resistente a antibióticos nos boxes de venda de peixe e nas mãos e cavidades nasal e oral de manipuladores de pescado da Feira de Pescado do Mucuripe, Fortaleza, Ceará. Todas as cepas isoladas foram resistentes à ampicilina e 44% apresentaram multiresistência.

  12. Characteristics of Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA Strains Isolated from Skin and Soft-Tissue Infections in Uruguay

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    Lorena Pardo

    2009-01-01

    Full Text Available We analyzed 90 nonduplicates community-associated methicillin-resistant S. aureus (CA-MRSA strains isolated from skin and soft-tissue infections. All strains were mecA positive. Twenty-four of the 90 strains showed inducible macrolide-lincosamide-streptogramin B resistance. All strains produced α-toxin; 96% and 100% of them displayed positive results for lukS-F and cna genes, respectively. Eigthy-five strains expressed capsular polysaccharide serotype 8. Six different pulsotypes were discriminated by pulsed-field gel electrophoresis (PFGE and three predominant groups of CA-MRSA strains (1, 2, and 4 were identified, in agreement with phenotypic and genotypic characteristics. Strains of group 1 (pulsotype A, CP8+, and Panton-Valentine leukocidin (PVL+ were the most frequently recovered and exhibited a PFGE band pattern identical to other CA-MRSA strains previously isolated in Uruguay and Brazil. Three years after the first local CA-MRSA report, these strains are still producing skin and soft-tissue infections demonstrating the stability over time of this community-associated emerging pathogen.

  13. Monoterpene isolated from the essential oil of Trachyspermum ammi is cytotoxic to multidrug-resistant Pseudomonas aeruginosa and Staphylococcus aureus strains

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    Faride Hosseinkhani

    2016-04-01

    Full Text Available Abstract INTRODUCTION: The aim of this study was to determine whether an herbal extract containing monoterpene exhibited activity against multidrug-resistant Staphylococcus aureus and Pseudomonas aeruginosa isolated from clinical infection samples. METHODS: The essential oil of Trachyspermum ammi (L. Sprague ex Turrill (Apiaceae fruit was extracted by hydrodistillation. Fruit residues were treated with hydrochloric acid and re-hydrodistilled to obtain volatile compounds. Compounds in the distilled oil were identified using gas-chromatography (GC and GC-mass spectrometry (MS. The antibiotic susceptibility of all bacterial isolates was analyzed using both the disc diffusion method and determination of the minimum inhibitory concentration (MIC. The sensitivity of antibiotic-resistant isolates to essential oil was also determined by using the disc diffusion method and MIC determination. RESULTS: Of 26 clinical isolates, 92% were multidrug-resistant (MDR. Aromatic monoterpenes (thymol, paracymene, and gamma-terpinene were the major (90% components of the oil. Growth of S. aureus strains was successfully inhibited by the oil, with an inhibitory zone diameter (IZD between 30-60mm and MIC <0.02μL/mL. The oil had no antimicrobial activity against clinical isolates of P. aeruginosa; rather, it prevented pigment production in these isolates. CONCLUSIONS: This study revealed that the essential oil of Trachyspermum ammi, which contains monoterpene, has good antibacterial potency. Monoterpenes could thus be incorporated into antimicrobial ointment formulas in order to treat highly drug-resistant S. aureus infections. Our findings also underscore the utility of research on natural products in order to combat bacterial multidrug resistance.

  14. 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

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    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.

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

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    Pellegrino, MS

    2011-07-01

    Full Text Available 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.

  16. 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.

  17. Antioxidant and antiproliferative potential of biosurfactants isolated from Lactobacillus casei and their anti-biofilm effect in oral Staphylococcus aureus strains.

    Science.gov (United States)

    Merghni, Abderrahmen; Dallel, Ines; Noumi, Emira; Kadmi, Yassine; Hentati, Hajer; Tobji, Samir; Ben Amor, Adel; Mastouri, Maha

    2017-03-01

    Biosurfactants also called bioemulsifiers are amphipathic compounds produced by many microorganisms that allow them to exhibit a wide range of biological activities. The aim of this study was to determine the antioxidant and antiproliferative potential of biosurfactants isolated from Lactobacillus casei and to assess their anti-adhesive and anti-biofilm abilities against oral opportunistic Staphylococcus aureus strains. The antioxidant activity of biosurfactant was evaluated using the in vitro scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The antiproliferative activity was determined on epithelial cell line (HEp-2) by the Methylthiazole tetrazolium (MTT) reduction assay. The anti-adhesive and antibiofilm activity against S. aureus strains were achieved using crystal violet staining. Our results revealed that the DPPH scavenging activity of biosurfactants at 5.0 mg/mL concentration is between 74.6 and 77.3%. Furthermore, biosurfactants showed antiproliferative potency against studied epithelial cells as judged by IC50 and its value ranged from 109.1 ± 0.84 mg/mL to 129.7 ± 0.52 mg/mL. The results of the growth inhibition indicate that biosurfactant BS-LBl was more effective against oral S. aureus strains 9P and 29P with an IC50 of 1.92 ± 0.26 mg/mL and 2.16 ± 0.12 mg/mL respectively. Moreover, both biosurfactants displayed important antibiofilm activity with eradication percentages ranging from 80.22 ± 1.33% to 86.21 ± 2.94% for the BS-LBl, and from 53.38 ± 1.77% to 64.42 ± 2.09% for the BS-LZ9. Our findings demonstrate that biosurfactants from L. casei strains exhibited considerable antioxidant and antiproliferative potencies and were able to inhibit oral S. aureus strains with important antibiofilm efficacy. They could have a promising role in the prevention of oral diseases.

  18. Isolation of nuc mutant isolates of Staphylococcus aureus from bovine clinical mastitis.

    Science.gov (United States)

    Zastempowska, E; Orczykowska-Kotyna, M; Lassa, H

    2014-06-01

    Isolates of Staphylococcus aureus with a mutation in the nuclease (nuc) gene were recovered from cases of bovine mastitis in Poland. Three S. aureus isolates from cows in one herd had a 42 base pair duplication in the nuc gene. These isolates belonged to sequence type 97 (ST97) and clonal complex 97 (CC97). They had a different spa type and multiple-locus variable-number tandem-repeat fingerprinting (MLVF) subtype than a S. aureus isolate without the nuc mutation from the same herd. Isolation of nuc mutant S. aureus strains from cases of bovine mastitis may confound diagnostic PCRs based on detection of the nuc gene.

  19. Avaliação da tolerância à vancomicina em 395 cepas hospitalares de Staphylococcus aureus resistentes à oxacilina Evaluation of the tolerance to vancomycin in 395 oxacillin-resistant Staphylococcus aureus strains isolated from Brazilian hospitals

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    Geraldo A. Oliveira

    2001-01-01

    Full Text Available O objetivo deste estudo foi avaliar a presença de tolerância à vancomicina em cepas de Staphylococcus aureus resistentes à oxacilina (Orsa isoladas de quatro hospitais da cidade de São Paulo. Foram estudadas 395 cepas Orsa isoladas de pacientes hospitalizados entre outubro de 1998 e maio de 2000. A determinação da concentração inibitória mínima (CIM e da concentração bactericida mínima (CBM para vancomicina foi realizada conforme padronizado pelo National Committee for Clinical Laboratory Standards (NCCLS. A tolerância à vancomicina foi definida como a razão CBM/CIM > ou = 32. Do total de cepas estudadas, 10,4% apresentaram CIM de 0,5µg/ml para vancomicina; 41,3%, CIM de 1µg/ml; 42,2%, CIM de 2µg/ml; e 6,1%, CIM de 4µg/ml. Em média, 49,1% dos Orsa apresentaram tolerância à vancomicina. Em conclusão, a tolerância à vancomicina entre as cepas Orsa foi considerada elevada. Conseqüentemente, aumentam as chances de falhas no tratamento com vancomicina, além de aumentar o risco da emergência de Staphylococcus aureus vancomicina-intermediário.The objective of this study was to evaluate the presence of tolerance to vancomycin in oxacillin-resistant Staphylococcus aureus (Orsa strains isolated from four hospitals in the city of São Paulo. From October/1998 to May/2000 we analysed 395 Orsa strains isolated from hospitalized patients. MIC and MBC to vancomycin were determined as standardised by National Committee for Clinical Laboratory Standards (NCCLS. Tolerance was defined as the ratio MBC/MIC > or = 32. The results showed that 10.4% of the Orsa strains presented a MIC of 0.5µg/mL for vancomycin, 41.3% presented a MIC of 1µg/mL, 42.2% a MIC of 2µg/mL and 6.1% a MIC of 4µg/mL. On average, 49,1% of the Orsa presented tolerance to vancomycin. We conclude that the tolerance to vancomycin amongst the Orsa strains was considered high. These high levels of tolerance augment the chances of failure in the treatment with

  20. Eugenol Provokes ROS-Mediated Membrane Damage-Associated Antibacterial Activity Against Clinically Isolated Multidrug-Resistant Staphylococcus aureus Strains

    OpenAIRE

    2016-01-01

    Due to the indiscriminate use of antibiotics, resistance to antibiotics has increased remarkably in Staphylococcus aureus. Vancomycin is the final drug to treat the S. aureus infection, but nowadays, resistance to this antibiotic is also increasing. So, the investigation of antibiotic resistance pattern is important. As there is already resistance to vancomycin, there is an urgent need to develop a new kind of antimicrobial to treat S. aureus infection. Eugenol may be the new drug of choice. ...

  1. 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

    Full Text Available Foram submetidas a PCR-Ribotipagem e aos testes de sensibilidade in vitro frente a 12 antimicrobianos 77 estirpes de Staphylococcus aureus isoladas em amostras de leite procedentes de 40 vacas da raça holandesa que apresentaram mastite subclínica, em uma propriedade rural localizada no Estado de São Paulo, Brasil. Os resultados obtidos revelaram quatro diferentes padrões de resistência a antimicrobianos, sendo observada a predominância de resistência à lincomicina entre 19 (24,7% estirpes de S.aureus. As 58 (75,3% estirpes restantes foram sensíveis aos 12 antimicrobianos testados. A PCR-ribotipagem revelou a ocorrência de nove padrões genotípicos distintos, além de apresentar uma capacidade discriminatória maior (D = 0,82 que a obtida nos antibiogramas (D = 0,42. Entre as 19 estirpes resistentes aos antimicrobianos, 14 (73,7% foram agrupadas em três padrões de ribotipagem e, destas, 13 (92,9% apresentaram resistência à eritromicina e à lincomicina, isoladamente ou em associação. O grande número de ribotipos e de padrões de resistência a antimicrobianos observados nesta propriedade demonstrou que há grande heterogeneidade genética em populações naturais de S. aureus, fato este que deve ser levado em consideração em programas de controle da mastite bovina.Seventy-seven S. aureus strains, isolated in milk samples obtained from 40 Holstein cows suffering from subclinical mastitis in a dairy herd in the state of São Paulo - Brazil, were undergone to PCR-ribotyping and in vitro susceptibility testing to 12 antimicrobial drugs. PCR-ribotyping revealed nine different patterns and presented a higher discriminatory power (D = 0.82 in comparison with the in vitro antibiotic susceptibility test (D = 0.42. Moreover,, the results showed four antibiotic resistance patterns, with the resistance to lincomycin being the most predominant and comprising 19 (24.7% S. aureus strains. The other 58 (75.3% isolates were sensitive to all

  2. Drug resistance of 115 Staphylococcus aureus strains isolated from blood culture%155例血培养金黄色葡萄球菌耐药分析

    Institute of Scientific and Technical Information of China (English)

    郝秀红; 赵强元; 郭建巍; 李艳君; 钱扬会; 刘力娟

    2013-01-01

    Objective To provide the evidence for treatment of Staphylococcus aureus infection by investigating its drug resistance in 2003-2011. Methods Blood samples of Staphylococcus aureus were taken using the blood culture bottle provided by Beijing Botai Technique Development Center and cultured in BacT/ALERT 3D automated blood culture system. The isolated bacteria were identified with the VITEK system, their drug sensitivity was tested by BIOMIC and their drug resistance was analyzed by WHONET 5.4 software. Results Of the 155 Staphylococcus aureus strains isolated from January 2003 to December 2011, 110 were methicillin-resistant S.aureus (MRSA), accounting for 70.9%. No resistance of Staphylococcus aureus to LNZ and VAN was found. The resistance of Staphylococcus aureus was below 30%to NIT and SXT, above 50%to TCY, LVX, CLX, CIP, CZO, AZM, ERY and PEN, 21.6%to 7 commonly used antibiotics and 34.6%to 8 commonly used antibiotics, respectively. Conclusion Staphylococcus aureus isolated from blood culture is highly resistant to drugs. The MRSA is resistant to multiple drugs and its drug resistance monitoring should be strengthened.%  目的了解2003-2011年血培养中金黄色葡萄球菌的耐药性变迁,为临床治疗提供依据.方法采用北京伯泰技术开发中心血培养瓶采样,BacT/ALERT 3D全自动血培养仪进行培养,VITEK微生物仪进行鉴定,BIOMIC仪进行药敏测试,WHONET5.4软件进行耐药性分析.结果2003年1月-2011年12月从临床送检的血培养标本分离出金葡菌155株,其中耐甲氧西林金黄色葡萄球菌(methicillin resistant staphylococcus aureus,MRSA)110株,MRSA在金葡菌中平均发生率为70.9%;9年间金葡菌对万古霉素、利奈唑胺未发现耐药株;对呋喃妥因、复方新诺明敏感性尚好,耐药率<30%;对四环素、左氧氟沙星、克林霉素、环丙沙星、头孢唑啉、阿齐霉素、红霉素、青霉素耐药率均达50%以上,且表现为

  3. Variability of antibiotic susceptibility and toxin production of Staphylococcus aureus strains isolated from skin, soft tissue, and bone related infections

    NARCIS (Netherlands)

    Sina, Haziz; Ahoyo, Theodora A.; Moussaoui, Wardi; Keller, Daniel; Bankole, Honore S.; Barogui, Yves; Stienstra, Ymkje; Kotchoni, Simeon O.; Prevost, Gilles; Baba-Moussa, Lamine

    2013-01-01

    Background: Staphylococcus aureus is an opportunistic commensal bacterium that mostly colonizes the skin and soft tissues. The pathogenicity of S. aureus is due to both its ability to resist antibiotics, and the production of toxins. Here, we characterize a group of genes responsible for toxin produ

  4. Staphylococcus aureus isolated from tonsillectomized adult patients with recurrent tonsillitis.

    Science.gov (United States)

    Katkowska, Marta; Garbacz, Katarzyna; Stromkowski, Józef

    2017-01-01

    The aim of this study was to analyze the prevalence and antibiotic resistance of Staphylococcus aureus strains from 118 tonsillectomized adults due to recurrent tonsillitis (RT). The study included strains isolated from the tonsillar surface prior to tonsillectomy, recovered from the tonsillar core at the time of surgery, and from the posterior throat 2-4 weeks after the procedure. Susceptibility of isolates to 19 antibiotics was tested in line with the Clinical and Laboratory Standards Institute recommendations. Irrespective of the stage, the most commonly isolated bacteria were gram-positive cocci, and among them S. aureus. The tonsillar core was the most common site of S. aureus isolation (30.5%), followed by the tonsillar surface (10.8%) and the posterior pharynx (5.9%). This difference turned out to be statistically significant (p aureus seems to be the most common pathogen isolated from patients tonsillectomized due to RT. Staphylococcal isolates associated with RT are present mostly within the tonsillar core and susceptible to most antibiotics. They are typically isolated from patients between 21 and 30 years of age. Tonsillectomy results in less frequent isolation of S. aureus strains.

  5. Prevalence of genes encoding pyrogenic toxin superantigens and exfoliative toxins among strains of Staphylococcus aureus isolated from blood and nasal specimens

    NARCIS (Netherlands)

    Becker, Karsten; Friedrich, Alexander W; Lubritz, Gabriele; Weilert, Maria; Peters, Georg; Von Eiff, Christof

    2003-01-01

    A total of 429 different Staphylococcus aureus isolates encompassing 219 blood isolates and 210 isolates taken from anterior nares were systematically searched by two multiplex PCR-DNA enzyme immunoassays (PCR-DEIA) for exfoliative toxin (ET) genes eta and etb, as well as for the classical members o

  6. Quantitative differences in antibiotic resistance between methicillin-resistant and methicillin-susceptible Staphylococcus aureus strains isolated in Hungary, Austria and Macedonia.

    Science.gov (United States)

    Horvath, A; Rozgonyi, F; Pesti, N; Kocsis, E; Malmos, G; Kristof, K; Nagy, K; Lagler, H; Presterl, E; Stich, K; Gattringer, R; Kotolacsi, G; Cekovska, Z; Graninger, W

    2010-08-01

    The aim of this study was to compare the quantitative susceptibility of methicillin-resistant and -susceptible Staphylococcus aureus (MRSA and MSSA) strains from three European countries to nine antistaphylococcal agents. The antibiotic susceptibility of 274 MRSA and 284 MSSA strains from Hungary, Austria and macedonia was tested by the broth microdilution method. The clonal relationship of strains was determined by pulsed-field gel electrophoresis. Intermediate susceptibility to vancomycin appeared in Macedonian MRSA strains. Macedonian MRSA strains had high-level amikacin and gentamicin resistance. MSSA strains generally were susceptible to all drugs at minimum inhibitory concentrations (MIC(50)) except for gentamicin resistance in Macedonian strains. In Hungary and Austria a common antibiotic resistance phenotype of MRSA predominated, while in macedonia three other phenotypes were also prevalent. Geographical differences in the resistance of S. aureus are still high. Since resistance levels of MRSA and MSSA strains differ extensively, they should be considered separately for antibiotic resistance analysis.

  7. Characterization of Staphylococcus aureus Strains Isolated from Czech Cystic Fibrosis Patients: High Rate of Ribosomal Mutation Conferring Resistance to MLS(B) Antibiotics as a Result of Long-Term and Low-Dose Azithromycin Treatment.

    Science.gov (United States)

    Tkadlec, Jan; Vařeková, Eva; Pantůček, Roman; Doškař, Jiří; Růžičková, Vladislava; Botka, Tibor; Fila, Libor; Melter, Oto

    2015-08-01

    Staphylococcus aureus is one of the most frequent pathogens infecting the respiratory tract of patients with cystic fibrosis (CF). This study was the first to examine S. aureus isolates from CF patients in the Czech Republic. Among 100 S. aureus isolates from 92 of 107 observed patients, we found a high prevalence of resistance to macrolide-lincosamide-streptogramin B (MLS(B)) antibiotics (56%). More than half of the resistant strains (29 of 56) carried a mutation in the MLS(B) target site. The emergence of MLS(B) resistance and mutations conferring resistance to MLS(B) antibiotics was associated with azithromycin treatment (p=0.000000184 and p=0.000681, respectively). Methicillin resistance was only detected in 3% of isolates and the rate of resistance to other antibiotics did not exceed 12%. The prevalence of small-colony variant (SCV) strains was relatively low (9%) and eight of nine isolates with the SCV phenotype were thymidine dependent. The study population of S. aureus was heterogeneous in structure and both the most prevalent community-associated and hospital-acquired clonal lineages were represented. Of the virulence genes, enterotoxin genes seg (n=52), sei (n=49), and sec (n=16) were the most frequently detected among the isolates. The PVL genes (lukS-PV and lukF-PV) have not been revealed in any of the isolates.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Methicillin-resistant Staphylococcus aureus isolates in a hospital of Shanghai

    Science.gov (United States)

    Wang, Xiaoguang; Ouyang, Lin; Luo, Lingfei; Liu, Jiqian; Song, Chiping; Li, Cuizhen; Yan, Hongjing; Wang, Ping

    2017-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) strains are now common both in the health care setting and in the community. Active surveillance is critical for MRSA control and prevention. Specimens of patients (200 patients with 1119 specimens) as well as medical staff and hospital setting (1000 specimens) were randomly sampled in a level 2 hospital in Shanghai from September 2011 to August 2012. Isolation, cultivation and identification of S. aureus were performed. Totally, 67 S. aureus strains were isolated. 32 S. aureus strains were isolated from patient samples; 13 (13/32, 40.6%) of the 32 S. aureus isolates were MRSA; sputum sample and patients in the department of general internal medicine were the most frequent specimen and patient group for S. aureus strains isolation. Remaining 35 S. aureus strains were isolated from the medical staff and hospital setting; 20 (20/35, 57.1%) of the 35 S. aureus isolates were MRSA; specimens sampled from doctors and nurses’ hands and nose and hospital facilities were the most frequent samples to isolate S. aureus. Resistant and virulent genes detection showed that, all 33 MRSA strains were mecA positive which accounts for 49.3% of the 67 S. aureus strains; 38 isolates were Panton-Valentine leukocidin (PVL) gene positive which accounts for 56.7% of the 67 S. aureus strains; and 17 (17/67, 25.4%) isolates are mecA and PVL genes dual positive. Multidrug-resistant strains of MRSA and PVL positive S. aureus are common in patients, medical staff and hospital setting, the potential health threat is worthy of our attention. PMID:28030828

  10. Methicillin-resistant staphylococcus aureus isolates in a hospital of shanghai.

    Science.gov (United States)

    Wang, Xiaoguang; Ouyang, Lin; Luo, Lingfei; Liu, Jiqian; Song, Chiping; Li, Cuizhen; Yan, Hongjing; Wang, Ping

    2017-01-24

    Methicillin-resistant Staphylococcus aureus (MRSA) strains are now common both in the health care setting and in the community. Active surveillance is critical for MRSA control and prevention. Specimens of patients (200 patients with 1119 specimens) as well as medical staff and hospital setting (1000 specimens) were randomly sampled in a level 2 hospital in Shanghai from September 2011 to August 2012. Isolation, cultivation and identification of S. aureus were performed. Totally, 67 S. aureus strains were isolated. 32 S. aureus strains were isolated from patient samples; 13 (13/32, 40.6%) of the 32 S. aureus isolates were MRSA; sputum sample and patients in the department of general internal medicine were the most frequent specimen and patient group for S. aureus strains isolation. Remaining 35 S. aureus strains were isolated from the medical staff and hospital setting; 20 (20/35, 57.1%) of the 35 S. aureus isolates were MRSA; specimens sampled from doctors and nurses' hands and nose and hospital facilities were the most frequent samples to isolate S. aureus. Resistant and virulent genes detection showed that, all 33 MRSA strains were mecA positive which accounts for 49.3% of the 67 S. aureus strains; 38 isolates were Panton-Valentine leukocidin (PVL) gene positive which accounts for 56.7% of the 67 S. aureus strains; and 17 (17/67, 25.4%) isolates are mecA and PVL genes dual positive. Multidrug-resistant strains of MRSA and PVL positive S. aureus are common in patients, medical staff and hospital setting, the potential health threat is worthy of our attention.

  11. Molecular Characterization of Methicillin Resistant Staphylococcus aureus Strains Isolated from Intensive Care Units in Iran: ST22-SCCmec IV/t790 Emerges as the Major Clone.

    Directory of Open Access Journals (Sweden)

    Mehdi Goudarzi

    Full Text Available The emergence of methicillin-resistant Staphylococcus aureus (MRSA in different patient populations is a major public health concern. This study determined the prevalence and distribution of circulating molecular types of MRSA in hospitalized patients in ICU of hospitals in Tehran.A total of 70 MRSA isolates were collected from patients in eight hospitals. Antimicrobial resistance patterns were determined using the disk diffusion method. The presence of toxin encoding genes and the vancomycin resistance gene were determined by PCR. The MRSA isolates were further analyzed using multi-locus sequence, spa, SCCmec, and agr typing.The MRSA prevalence was 93.3%. Antimicrobial susceptibility testing revealed a high resistance rate (97.1% to ampicillin and penicillin. The rate of resistance to the majority of antibiotics tested was 30% to 71.4%. Two isolates belonging to the ST22-SCCmec IV/t790 clone (MIC ≥ 8 μg/ml had intermediate resistance to vancomycin. The majority of MRSA isolates (24.3% were associated with the ST22-SCCmec IV/t790 clone; the other MRSA clones were ST859-SCCmec IV/t969 (18.6%, ST239-SCCmec III/t037 (17.1%, and ST291-SCCmec IV/t030 (8.6%.The circulating MRSA strains in Iranian hospitals were genetically diverse with a relatively high prevalence of the ST22-SCCmec IV/t790 clone. These findings support the need for future surveillance studies on MRSA to better elucidate the distribution of existing MRSA clones and detect emergence of new MRSA clones.

  12. Molecular study on methicillin-resistant Staphylococcus aureus strains isolated from dogs and associated personnel in Jordan

    Directory of Open Access Journals (Sweden)

    Yaser Hamadeh Tarazi

    2015-11-01

    Conclusions: MRSA is prevalent in house dogs, as well as in dog rearing centers and among their strongly associated personnel. A strong association was found between the MRSA isolates from dogs and those from humans who are in close contact. In addition, MRSA isolates showed a high rate of multi-resistance compared to MSSA isolates.

  13. Study of Decreased Susceptibility to Vancomycin in Methicillin-Resistant Staphylococcus aureus Strains isolated from a Romanian Multidisciplinary Emergency Hospital

    OpenAIRE

    Vas Krisztina Eszter; Szász Izabella; Molnár Szabolcs (1973-) (ortopéd sebész, traumatológus); Lőrinczi Lilla; Székely Edit

    2014-01-01

    Relevanța clinică a tulpinilor Staphylococcus aureus cu susceptibilitate heterointermediară la vancomicină (hVISA) nu este complet elucidată, totuși acestea pot fi responsabile pentru eșec terapeutic la pacienții tratați cu vancomicină. Lipsa standardizării și complexitatea metodelor de detectare sunt provocări importante in identificarea acestor tulpini. Scopul studiului a fost evaluarea frecvenței tulpinilor hVISA în Spitalul Clinic Județean de Urgență Târgu-Mureș. O sută douăzeci și două d...

  14. Study of Decreased Susceptibility to Vancomycin in Methicillin-Resistant Staphylococcus aureus Strains isolated from a Romanian Multidisciplinary Emergency Hospital

    Directory of Open Access Journals (Sweden)

    Vas Krisztina Eszter

    2014-06-01

    Full Text Available Relevanța clinică a tulpinilor Staphylococcus aureus cu susceptibilitate heterointermediară la vancomicină (hVISA nu este complet elucidată, totuși acestea pot fi responsabile pentru eșec terapeutic la pacienții tratați cu vancomicină. Lipsa standardizării și complexitatea metodelor de detectare sunt provocări importante in identificarea acestor tulpini. Scopul studiului a fost evaluarea frecvenței tulpinilor hVISA în Spitalul Clinic Județean de Urgență Târgu-Mureș. O sută douăzeci și două de tulpini de S. aureus meticilino-rezistente (MRSA, susceptibile la vancomicina cu E-test standard (CMI≤2 mg/L, au fost testate pentru heterorezistență cu metoda E-test GRD (Glycopeptide Resistance Detection. Pentru confirmare s-a folosit analiza populațională. Douăzeci și patru de tulpini (19.5% au fost selectate cu metoda screening. Două dintre acestea (1.63% au fost confirmate fiind hVISA, nici un izolat nu avea susceptibilitate intermediară la vancomicină (VISA. Rata tulpinilor hVISA a fost scazută. Monitorizarea lor poate fi totuși importanta, luând in considerare ca glicopeptidele sunt larg utilizate pentru tratamentul infecțiilor severe cauzate de MRSA.

  15. Staphylococcal cassette chromosome mec characterization of methicillin-resistant Staphylococcus aureus strains isolated at the military hospital of Constantine/Algeria.

    Science.gov (United States)

    Ouchenane, Z; Agabou, A; Smati, F; Rolain, J-M; Raoult, D

    2013-12-01

    Staphylococcal cassette chromosome mec is a genetic mobile element that carries the gene mecA mediating the methicillin resistance in staphylococci. The aim of this study is to type the Staphylococcal cassette chromosome mec (SCCmec) in 64 non-redundant methicillin-resistant Staphylococcus aureus (MRSA) strains recovered at the military hospital of Constantine (Algeria) between 2005 and 2007. Methicillin resistance was detected by oxacillin and cefoxitin discs and PBP2a test, and then confirmed by mecA PCR. The SCCmec complex types were determined by real time PCR. The analysis showed that 50 isolates were hospital acquired (HA-MRSA) and 14 were community-acquired (CA-MRSA). SCCmec type IV and V (traditionally attributed to CA-MRSA) were harbored by both HA-MRSA and CA-MRSA, while SCCmec type I, II and III were not recorded. These findings motivate more investigations to be carried on HA-MRSA in our hospital and other national health care centers.

  16. Biochemical characters and antibiotic susceptibility of Staphylococcus aureus isolates

    Institute of Scientific and Technical Information of China (English)

    Subhankari Prasad Chakraborty; Santanu Kar Mahapatra; Somenath Roy

    2011-01-01

    Objective: To observe the biochemical characters and antibiotic susceptibility of isolated Staphylococcus aureus (S. auerus) strains against some conventional and traditional antibiotics.Methods:Bacterial culture was done in Mueller-Hinton broth at 37 ℃. Characters of these strains were determined by traditional biochemical tests such as hydrolysis test of gelatin, urea, galactose, starch and protein, and fermentation of lactose and sucrose. Antibiotic susceptibility were carried out by minimum inhibitory concentration test, minium bactericidal concentration test, disc agar diffusion test and brain heart infusion oxacillin screening agar. Results: From this study, it was observed that 100% S. aureus isolates showed positive results in gelatin, urea and galactose hydrolysis test, 50% isolates were positive in starch hydrolysis test, 35% in protein hydrolysis test, 100% isolates in lactose fermenting test, but no isolate was positive in sucrose fermenting test. Antibiotic susceptibility testing suggested that 20% of isolates were resistant to kanamycin and 46.67% were resistant to oxacillin. Conclusions: These findings show that all these isolates have gelatin, urea, galactose hydrolysis and lactose fermenting activity. 20% of these isolates were resistant to kanamycin and 46.67% were resistant to oxacillin. Thirty post operative pathogenic isolated S. aureus strains were used in this study.

  17. 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 mol

  18. Prevalence of staphylococcal enterotoxins, toxin genes and genetic-relatedness of foodborne Staphylococcus aureus strains isolated in the Marmara Region of Turkey.

    Science.gov (United States)

    Aydin, Ali; Sudagidan, Mert; Muratoglu, Karlo

    2011-08-02

    Staphylococcus aureus is a major foodborne pathogen and it has the ability to produce a number of extracellular toxins. We analyzed 1070 food samples obtained from retail markets and dairy farms in the Marmara Region of Turkey for the presence of S. aureus. Out of 147 isolates, 92 (62.6%) were enterotoxigenic. PCR was used to investigate the presence of staphylococcal enterotoxin genes (sea, seb, sec, sed, see, seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq and seu), exfoliative toxin genes (eta and etb) and the toxic-shock syndrome toxin gene (tst). The PCR results showed that 53.3% of the isolates contained staphylococcal enterotoxin-like (SEl) toxin genes (seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq and seu) which were more frequent than classical enterotoxin genes (sea to see). Furthermore, seo, sei, sem, seg, seu and sec were found in 37.0, 32.7, 30.4, 29.3, 29.3 and 27.2% of the isolates, respectively. The tst gene was detected and confirmed by DNA sequencing in 9 isolates. The presence of eta and etb were not found in the isolates. Enterotoxigenic capabilities of isolates with SEA-SEE were investigated by ELISA. Enterotoxigenic S. aureus isolates produced one to three enterotoxins, with the most frequently produced types being enterotoxin A and C. There was a correlation of 72.1% between production of a specific toxin and the presence of the respective genes. PFGE analysis was used to identify genetic-relatedness of enterotoxigenic S. aureus isolates and the results revealed that 13 groups of isolates from different or the same origin that contained the same genes showed 100% homology with indistinguishable band patterns. The other enterotoxigenic isolates showed related band patterns with 72-86% homology in sea-, 61-90% homology in sec-, 80-96% homology in seh-, and 69-96% homology in sep-positive isolates. To our knowledge, this is the first study to examine enterotoxins and related gene contents of S. aureus food isolates in the Marmara

  19. Implementation of a novel in vitro model of infection of reconstituted human epithelium for expression of virulence genes in methicillin-resistant Staphylococcus aureus strains isolated from catheter-related infections in Mexico

    OpenAIRE

    Paniagua-Contreras, Gloria Luz; Monroy-Pérez, Eric; Vaca-Paniagua, Felipe; RODRÍGUEZ-MOCTEZUMA,JOSÉ RAYMUNDO; Negrete-Abascal, Erasmo; Vaca, Sergio

    2014-01-01

    Background Methicillin-resistant Staphylococcus aureus (MRSA) are clinically relevant pathogens that cause severe catheter-related nosocomial infections driven by several virulence factors. Methods We implemented a novel model of infection in vitro of reconstituted human epithelium (RHE) to analyze the expression patterns of virulence genes in 21 MRSA strains isolated from catheter-related infections in Mexican patients undergoing haemodialysis. We also determined the phenotypic and genotypic...

  20. Produção de enterotoxinas e da toxina da síndrome do choque tóxico por cepas de Staphylococcus aureus isoladas na mastite bovina Production of enterotoxins and toxic shock syndrome toxin by Staphylococcus aureus strains isolated from bovine mastitis

    Directory of Open Access Journals (Sweden)

    A. Nader Filho

    2007-10-01

    Full Text Available A total of 72 strains of Staphylococcus aureus were examined for the production of staphylococcal enterotoxins (SE A, B, C, D and toxic shock syndrome toxin (TSST-1. The strains were isolated from milk samples from cows with mastitis in dairy herds of São Paulo State, Brazil. Off 72 isolates, 38 (52.8% produced SEA, 38 (52.8% SEB, 32 (44.4% SED, 28 (38.9% SEC and 27 (37.5% TSST-1. From the 72 strains, 66 (91.7% produced, at least, one or more toxin, including TSST-1.

  1. The Prevalence of Resistance to Methicillin in Staphylococcus aureus Strains Isolated from Patients by PCR Method for Detec-tion of mecA and nuc Genes.

    OpenAIRE

    Roxana Sahebnasagh; Horieh Saderi; Parviz Owlia

    2014-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is the main cause of hospital infection emerged over the last decades. Rapid detection of MRSA is important for patient care and proper usage of infection control. Detection of mecA genes (encoding resistance to methicillin and other similar antibiotics) and nuc genes (encoding staphylococcal thermostable nuclease) by PCR method is now considered for rapid identification of MRSA strain. The aim of this study was to determine the prevalence of...

  2. The Prevalence of Resistance to Methicillin in Staphylococcus aureus Strains Isolated from Patients by PCR Method for Detec-tion of mecA and nuc Genes

    OpenAIRE

    SAHEBNASAGH, Roxana; Saderi, Horieh; Owlia, Parviz

    2014-01-01

    Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA) is the main cause of hospital infection emerged over the last decades. Rapid detection of MRSA is important for patient care and proper usage of infection control. Detection of mecA genes (encoding resistance to methicillin and other similar antibiotics) and nuc genes (encoding staphylococcal thermostable nuclease) by PCR method is now considered for rapid identification of MRSA strain. The aim of this study was to determi...

  3. 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...

  4. Existence of two groups of Staphylococcus aureus strains isolated from bovine mastitis based on biofilm formation, intracellular survival, capsular profile and agr-typing.

    Science.gov (United States)

    Bardiau, Marjorie; Caplin, Jonathan; Detilleux, Johann; Graber, Hans; Moroni, Paolo; Taminiau, Bernard; Mainil, Jacques G

    2016-03-15

    Staphylococcus (S.) aureus is recognised worldwide as an important pathogen causing contagious acute and chronic bovine mastitis. Chronic mastitis account for a significant part of all bovine cases and represent an important economic problem for dairy producers. Several properties (biofilm formation, intracellular survival, capsular expression and group agr) are thought to be associated with this chronic status. In a previous study, we found the existence of two groups of strains based on the association of these features. The aim of the present work was to confirm on a large international and non-related collection of strains the existence of these clusters and to associate them with case history records. In addition, the genomes of eight strains were sequenced to study the genomic differences between strains of each cluster. The results confirmed the existence of both groups based on capsular typing, intracellular survival and agr-typing: strains cap8-positive, belonging to agr group II, showing a low invasion rate and strains cap5-positive, belonging to agr group I, showing a high invasion rate. None of the two clusters were associated with the chronic status of the cow. When comparing the genomes of strains belonging to both clusters, the genes specific to the group "cap5-agrI" would suggest that these strains are better adapted to live in hostile environment. The existence of these two groups is highly important as they may represent two clusters that are adapted differently to the host and/or the surrounding environment.

  5. Heterogeneity of host TLR2 stimulation by Staphylocoocus aureus isolates.

    Directory of Open Access Journals (Sweden)

    Dina Hilmi

    Full Text Available High lipoprotein expression and potent activation of host Toll-like receptor-2 (TLR2 are characteristic features of the staphylococcal species. Expression of TLR2 in the host is important for clearance of Staphylococcus aureus infection and host survival. Thus, we hypothesized that bacterial regulation of its intrinsic TLR2-stimulatory capacity could represent a means for immune evasion or host adaptation. We, therefore, compared clinical S. aureus isolates in regards to their TLR2 activation potential and assessed the bacterial factors that modulate TLR2-mediated recognition. S. aureus isolates displayed considerable variability in TLR2-activity with low to absent TLR2-activity in 64% of the isolates tested (68/106. Notably, strain-specific TLR2-activity was independent of the strain origin, e.g. no differences were found between strains isolated from respiratory specimen from cystic fibrosis patients or those isolated from invasive disease specimen. TLR2-activity correlated with protein A expression but not with the agr status. Capsule expression and small colony variant formation had a negative impact on TLR2-activity but any disruption of cell wall integrity enhanced TLR2 activation. Altogether, heterogeneity in host TLR2-activity reflects differences in metabolic activity and cell wall synthesis and/or remodeling.

  6. Drugs resistance and penicillinase activity in skin isolated Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Bhat K

    1990-01-01

    Full Text Available A study was carried out to evaluate the drug resistance pattern and penicillinase production in skin isolated Staphylococcus aurpus. The disk diffusion method showed prevalence of: multidrug resistance among S. aureus, strains, isolated from locafised skin abscesses. method for detection of penicilfinase could detect this enzyme m 98.60/o of the isolates all fo which were resistant to penicillin and ampicillin. C16xacillin resistance as detected by the agar dilution method was found in 1.4% of the isolates. On the whole cloxacillin and gentamy′cin were found to be the most effective ′antistaphylococcal antibotics.

  7. Assessment of adhesion, invasion and cytotoxicity potential of oral Staphylococcus aureus strains.

    Science.gov (United States)

    Merghni, Abderrahmen; Ben Nejma, Mouna; Helali, Imen; Hentati, Hajer; Bongiovanni, Antonino; Lafont, Frank; Aouni, Mahjoub; Mastouri, Maha

    2015-09-01

    The oral cavity is regarded as a relevant site for Staphylococcus aureus colonization. However, characterization of virulence mechanisms of oral S. aureus remains to be uncovered. In this study, twenty one S. aureus strains isolated from the oral cavity of Tunisian patients were screened for adherence, invasion and cytotoxicity against HeLa cells. In addition, the presence of adhesins (icaA, icaD, can, fnbA and fnbB) and α-hemolysin (hla) genes in each strain was achieved by polymerase chain reaction (PCR). Our finding revealed that oral S. aureus strains were able to adhere and invade epithelial cells, with variable degrees (P toxin was found in 52.4% of the isolates. All these virulence factors give to S. aureus the right qualities to become a redoubtable pathogen associated to oral infections.

  8. 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.

  9. Phage sensitivity and prophage carriage in Staphylococcus aureus isolated from foods in Spain and New Zealand.

    Science.gov (United States)

    Gutiérrez, Diana; Rodríguez-Rubio, Lorena; García, Pilar; Billington, Craig; Premarante, Aruni; Rodríguez, Ana; Martínez, Beatriz

    2016-08-02

    Bacteriophages (phages) are a promising tool for the biocontrol of pathogenic bacteria, including those contaminating food products and causing infectious diseases. However, the success of phage preparations is limited by the host ranges of their constituent phages. The phage resistance/sensitivity profile of eighty seven Staphylococcus aureus strains isolated in Spain and New Zealand from dairy, meat and seafood sources was determined for six phages (Φ11, K, ΦH5, ΦA72, CAPSa1 and CAPSa3). Most of the S. aureus strains were sensitive to phage K (Myoviridae) and CAPSa1 (Siphoviridae) regardless of their origin. There was a higher sensitivity of New Zealand S. aureus strains to phages isolated from both Spain (ΦH5 and ΦA72) and New Zealand (CAPSa1 and CAPSa3). Spanish phages had a higher infectivity on S. aureus strains of Spanish dairy origin, while Spanish strains isolated from other environments were more sensitive to New Zealand phages. Lysogeny was more prevalent in Spanish S. aureus compared to New Zealand strains. A multiplex PCR reaction, which detected ΦH5 and ΦA72 sequences, indicated a high prevalence of these prophages in Spanish S. aureus strains, but were infrequently detected in New Zealand strains. Overall, the correlation between phage resistance and lysogeny in S. aureus strains was found to be weak.

  10. DiversiLab typing research of Staphyloccocus aureus strains isolated from food samples%对食品中分离的金黄色葡萄球菌进行DiversiLab分型研究

    Institute of Scientific and Technical Information of China (English)

    刘静宇; 凌莉; 陈春梅; 易敏英; 胡科峰

    2012-01-01

    Objective:To conduct molecular typing research for the 16 Staphyloccocus aureus strains isolated from food samples of Zhanjiang, in order to trace food borne diseases and provide early warning. Methods: DiversiLab Automated typing system was used to study the genotypes of the 16 Staphyloccocus aureus strains. Results: According to the diagnostic criteria, the 16 Staphyloccocus aureus strains were distributed to nine patterns. Among them, pattern 1 contained strains 0902 and 0901 ; Pattern 2 contained strains 0971, 0923, 0967, 09108 ; Pattern 3 contained strains 0969 , 0970, 10010; Pattern 4 contained strains 09118 and 09119. The rest five strains were distributed to five different patterns. Conclusion: DiversiLab typing results revealed the genetic characters and relationships of the 16 Staphyloccocus aureus strains accurately. The convenient and efficient DiversiLab automated typing system is a powerful molecular genotyping tool to monitor food borne pathogens as well as trace and warn food borne diseases.%目的:对来自湛江的食品样本中分离的16株金黄色葡萄球菌进行DiversiLab分型,研究其基因特征和聚类分布,为食源性疾病溯源及预警提供依据.方法:采用DiversiLab自动分型系统对16株金黄色葡萄球菌进行分子分型.结果:DiversiLab分型系统将16株金黄色葡萄球菌分为9个型别,其中P1型包含菌株0902和0901;P2型包含0971、0923、0967、09108菌株;P3型包含菌株0969、0970、10010;P4型包含菌株09118和09119.其余5株金黄色葡萄球菌的每一个菌株被分为一个单独的型别.结论:DiversiLab分型结果准确揭示了16株食品中金黄色葡萄球菌的遗传特征和亲缘关系;Diversilab自动化分型技术方便快捷、结果可靠,是监测分析食源性致病菌和对食源性疾病溯源及预警的有力工具.

  11. 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

  12. 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.

  13. 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 in Denm...

  14. Non-spa-typeable clinical Staphylococcus aureus strains are naturally occurring protein A mutants

    DEFF Research Database (Denmark)

    Baum, Cathrin; Haslinger-Löffler, Bettina; Westh, Henrik;

    2009-01-01

    Staphylococcus aureus is a major human pathogen responsible for increasing the prevalence of community- and hospital-acquired infections. Protein A (SpA) is a key virulence factor of S. aureus and is highly conserved. Sequencing of the variable-number tandem-repeat region of SpA (spa typing......) provides a rapid and reliable method for epidemiological studies. Rarely, non-spa-typeable S. aureus strains are encountered. The reason for this is not known. In this study, we characterized eight non-spa-typeable bacteremia isolates. Sequencing of the entire spa locus was successful for five strains...

  15. Human-associated Staphylococcus aureus strains within great ape populations in Central Africa (Gabon).

    Science.gov (United States)

    Nagel, M; Dischinger, J; Türck, M; Verrier, D; Oedenkoven, M; Ngoubangoye, B; Le Flohic, G; Drexler, J F; Bierbaum, G; Gonzalez, J-P

    2013-11-01

    The risk of serious infections caused by Staphylococcus aureus is well-known. However, most studies regarding the distribution of (clinically relevant) S. aureus among humans and animals took place in the western hemisphere and only limited data are available from (Central) Africa. In this context, recent studies focused on S. aureus strains in humans and primates, but the question of whether humans and monkeys share related S. aureus strains or may interchange strains remained largely unsolved. In this study we aimed to evaluate the distribution and spread of human-like S. aureus strains among great apes living in captivity. Therefore, a primate facility at the International Centre for Medical Research of Franceville (Gabon) was screened. We detected among the primates a common human S. aureus strain, belonging to the spa-type t148. It was isolated from three different individuals of the western lowland gorilla (Gorilla gorilla gorilla), of which one individual showed a large necrotizing wound. This animal died, most probably of a staphylococcal sepsis. Additionally, we discovered the t148 type among chimpanzees (Pan troglodytes) that were settled in the immediate neighbourhood of the infected gorillas. A detailed analysis by pulsed field gel electrophoresis showed that the gorilla and chimpanzee isolates represented two closely related strains. To our knowledge, this is the first report of a human-associated S. aureus strain causing disease in great apes. The simultaneous detection in gorillas and chimpanzees indicated an interspecies transmission of this S. aureus strain. Our results recommend that protection of wild animals must not only be based on habitat conservation, but also on the assessment of the risk of contact with human pathogens.

  16. Isolation and Identification of Vancomycin Resistant Staphylococcus aureus from Post Operative Pus Sample

    Directory of Open Access Journals (Sweden)

    Subhankari Prasad Chakraborty1, Santanu KarMahapatra1, Manjusri Bal2 and Somenath Roy1*

    2011-04-01

    Full Text Available Staphylococcus aureus is most frequently isolated pathogen causing bloodstream infections, skin and soft tissue infections and pneumonia. Recently, S. aureus have evolved resistance to both synthetic and traditional antibiotics. This study was carried out to isolate pathogenic S. aureus from post-operative pus sample, and VRSA was identified by evaluation of resistance patterns using conventional antibiotics. Thirty post operative pus samples were collected from nearby Hospital and species identification was confirmed by Gram staining, standard biochemical tests and PCR amplification of the nuc gene. Antibiotic susceptibility tests were carried out by MIC, MBC, DAD test and BHI vancomycin screening agar. VRSA were confirmed by PCR amplification of the vanA and vanB genes. From this study, it was observed that isolated S. aureus strains are pathogenic; 30% of strains were resistant to penicillin G, ampicillin and erythromycin; 26.67% strains were resistant to cephotaxime, gentamycin, streptomycin, tetracycline, chloramphenicol, norfloxacin, methicillin and vancomycin.

  17. CHROMOSOMAL MAPPING IN STRAINS OF STAPHYLOCOCCUS AUREUS,

    Science.gov (United States)

    STAPHYLOCOCCUS AUREUS , CHROMOSOMES), (*CHROMOSOMES, MAPPING), NITROSO COMPOUNDS, GUANIDINES, GENETICS, MUTATIONS, DRUGS, TOLERANCES(PHYSIOLOGY), TEST METHODS, DEOXYRIBONUCLEIC ACIDS, INHIBITION, RESISTANCE(BIOLOGY).

  18. Complete genome sequence of Staphylococcus aureus strain M1, a unique t024-ST8-IVa Danish methicillin-resistant S. aureus clone

    DEFF Research Database (Denmark)

    Larner-Svensson, Hanna; Worning, Peder; Bartels, Mette

    2013-01-01

    We report the genome sequence, in five contigs, of a methicillin-resistant Staphylococcus aureus isolate designated M1. This clinical isolate was from the index patient of a methicillin-resistant Staphylococcus aureus (MRSA) outbreak in Copenhagen, Denmark, that started in 2003. This strain is se...... is sequence type 8 (ST8), spa type t024, and staphylococcal cassette chromosome mec element (SCCmec) type IVa....

  19. Biochemical and Molecular Analysis of Staphylococcus aureus Clinical Isolates from Hospitalized Patients

    Directory of Open Access Journals (Sweden)

    Amit Karmakar

    2016-01-01

    Full Text Available Staphylococcus aureus is opportunistic human as well as animal pathogen that causes a variety of diseases. A total of 100 Staphylococcus aureus isolates were obtained from clinical samples derived from hospitalized patients. The presumptive Staphylococcus aureus clinical isolates were identified phenotypically by different biochemical tests. Molecular identification was done by PCR using species specific 16S rRNA primer pairs and finally 100 isolates were found to be positive as Staphylococcus aureus. Screened isolates were further analyzed by several microbiological diagnostics tests including gelatin hydrolysis, protease, and lipase tests. It was found that 78%, 81%, and 51% isolates were positive for gelatin hydrolysis, protease, and lipase activities, respectively. Antibiogram analysis of isolated Staphylococcus aureus strains with respect to different antimicrobial agents revealed resistance pattern ranging from 57 to 96%. Our study also shows 70% strains to be MRSA, 54.3% as VRSA, and 54.3% as both MRSA and VRSA. All the identified isolates were subjected to detection of mecA, nuc, and hlb genes and 70%, 84%, and 40% were found to harbour mecA, nuc, and hlb genes, respectively. The current investigation is highly important and informative for the high level multidrug resistant Staphylococcus aureus infections inclusive also of methicillin and vancomycin.

  20. Interspecific small molecule interactions between clinical isolates of Pseudomonas aeruginosa and Staphylococcus aureus from adult cystic fibrosis patients.

    Directory of Open Access Journals (Sweden)

    Alexandre Fugère

    Full Text Available Pseudomonas aeruginosa and Staphylococcus aureus are the most prevalent pathogens in airway infections of cystic fibrosis (CF patients. We studied how these pathogens coexist and interact with each other. Clinical isolates of both species were retrieved from adult CF patients. Culture supernatants from 63 P. aeruginosa isolates triggered a wide range of biofilm-stimulatory activities when added to the culture of a control S. aureus strain. The extent of biofilm formation by S. aureus was positively correlated to the levels of the 2-alkyl-4-(1H-quinolones (AQs Pseudomonas Quinolone Signal (PQS and 2-heptyl-4-hydroxy quinoline N-oxide (HQNO produced by the P. aeruginosa isolates. Supernatants from P. aeruginosa isogenic mutants deficient in PQS and HQNO production stimulated significantly less biofilm formation by S. aureus than that seen with the parental strain PA14. When studying co-isolated pairs of P. aeruginosa and S. aureus retrieved from patients showing both pathogens, P. aeruginosa supernatants stimulated less biofilm production by the S. aureus counterparts compared to that observed using the control S. aureus strain. Accordingly, some P. aeruginosa isolates produced low levels of exoproducts and also some of the clinical S. aureus isolates were not stimulated by their co-isolates or by PA14 despite adequate production of HQNO. This suggests that colonization of the CF lungs promotes some type of strain selection, or that co-existence requires specific adaptations by either or both pathogens. Results provide insights on bacterial interactions in CF.

  1. High-resolution subtyping of Staphylococcus aureus strains by means of Fourier-transform infrared spectroscopy.

    Science.gov (United States)

    Johler, Sophia; Stephan, Roger; Althaus, Denise; Ehling-Schulz, Monika; Grunert, Tom

    2016-05-01

    Staphylococcus aureus causes a variety of serious illnesses in humans and animals. Subtyping of S. aureus isolates plays a crucial role in epidemiological investigations. Metabolic fingerprinting by Fourier-transform infrared (FTIR) spectroscopy is commonly used to identify microbes at species as well as subspecies level. In this study, we aimed to assess the suitability of FTIR spectroscopy as a tool for S. aureus subtyping. To this end, we compared the subtyping performance of FTIR spectroscopy to other subtyping methods such as pulsed field gel electrophoresis (PFGE) and spa typing in a blinded experimental setup and investigated the ability of FTIR spectroscopy for identifying S. aureus clonal complexes (CC). A total of 70 S. aureus strains from human, animal, and food sources were selected, for which clonal complexes and a unique virulence and resistance gene pattern had been determined by DNA microarray analysis. FTIR spectral analysis resulted in high discriminatory power similar as obtained by spa typing and PFGE. High directional concordance was found between FTIR spectroscopy based subtypes and capsular polysaccharide expression detected by FTIR spectroscopy and the cap specific locus, reflecting strain specific expression of capsular polysaccharides and/or other surface glycopolymers, such as wall teichoic acid, peptidoglycane, and lipoteichoic acid. Supervised chemometrics showed only limited possibilities for differentiation of S. aureus CC by FTIR spectroscopy with the exception of CC45 and CC705. In conclusion, FTIR spectroscopy represents a valuable tool for S. aureus subtyping, which complements current molecular and proteomic strain typing.

  2. Isolates of Staphylococcus aureus and saprophyticus resistant to antimicrobials isolated from the Lebanese aquatic environment.

    Science.gov (United States)

    Harakeh, Steve; Yassine, Hadi; Hajjar, Shady; El-Fadel, Mutasem

    2006-08-01

    The indiscriminate use of antimicrobials especially in developing countries has evoked serious bacterial resistance and led to the emergence of new and highly resistant strains of bacteria to commonly used antimicrobials. In Lebanon, pollution levels and bacterial infections are increasing at a high rate as a result of inadequate control measures to limit untreated effluent discharges into the sea or freshwater resources. The aim of this study was to isolate and molecularly characterize various Staphylococcus strains isolated from sea water, fresh water, sediments, and crab samples collected from representative communities along the coast of Lebanon. The results on the antimicrobial resistance indicated that the level of resistance of Staphylococcus aureus varied with various antimicrobials tested. The resistance patterns ranged between 45% in freshwater isolates and 54.8% in seawater ones. Fifty one percent of the tested isolates have shown resistance to at least one of the five tested antimicrobials; with seawater isolates exhibiting the highest rates of antimicrobial resistance.

  3. 牛源耐甲氧西林金黄色葡萄球菌的检测%Detection of Methicillin-resistant Staphylococcus aureus Strains Isolated from Bovine Mastitis

    Institute of Scientific and Technical Information of China (English)

    苏洋; 蒲万霞; 邓海平; 李春慧; 梁红雁; 陈智华

    2013-01-01

    本研究旨在了解甘肃地区奶牛乳房炎金黄色葡萄球菌的耐药性和耐甲氧西林金黄色葡萄球菌的感染情况,为奶牛乳房炎的防制提供理论依据.采用KB纸片扩散法,检测17株金黄色葡萄球菌对8种不同抗菌药物的敏感性;再用琼脂稀释法检测了苯唑西林、万古霉素对金黄色葡萄球菌的最小抑菌浓度(MICs);头孢西丁纸片扩散法和PCR扩增特异性mecA耐药基因对所有受试菌株进行全面的耐甲氧西林金黄色葡萄球菌检测.结果表明,菌株对青霉素、磺胺异恶唑具有较强抗性,而对环丙沙星、头孢唑啉、万古霉素和苯唑西林全敏感;头孢西丁纸片扩散法未能检测出表型为MRSA的阳性菌株,而PCR方法却检测出8株mecA基因阳性菌株,且这些菌株的苯唑西林MIC均小于2μg/mL.菌株的耐药情况较严重,对甲氧西林敏感而携带mecA基因的菌株高频存在于被调查地区的奶牛场中.%The aim of present study was to investigate the antimicrobial resistance, and the prevalence of methicillin-resistant Staphylococcus aureus (S. aureus) isolated from bovine mastitis in Gansu province, to provide credible theory evidence for prevention and treatment on bovine mastitis. Eight commonly used antimicrobial agents were used for determining antimicrobial susceptibility of 17 total S. aureus strains by disk diffusion method. Agar screen method was used for determining the oxacil-lin and vancomycin minimum inhibitory concentration value as well. Disk diffusion method using the cephamycin antibiotics ce-foxitin and detection of mecA gene by PCR assay were performed to detect the presence of MRSA. Most of strains showed a high resistance for penicillin and sulfafurazole, yet keeping complete sensitivity for ciprofloxacin, cefazolin, vancomycin and ox-acillin. None MRS A isolate was identified by the phenotypic detection method, but eight MRSA isolates with the MIC of oxac-illin lower than 2 μg/mL were

  4. Detecção da toxina-1 da síndrome do choque tóxico em amostras de Staphylococcus aureus isoladas de mastite bovina Detection of toxic shock syndrome toxin by Staphylococcus aureus strains isolated from bovine mastitis

    Directory of Open Access Journals (Sweden)

    H.F.T. Cardoso

    2000-02-01

    Full Text Available Este trabalho teve por objetivo caracterizar a produção da toxina da síndrome do choque tóxico (TSST-1 e de enterotoxinas estafilocócicas (SE A, B, C e D em 127 amostras de S. aureus, isoladas de amostras de leite proveniente de vacas com mastite no Estado de Minas Gerais, entre 1994 e 1997. A verificação da produção de toxinas foi feita pela técnica de sensibilidade ótima em placa. Das 127 amostras testadas, 60 (47% eram produtoras de TSST-1 e 54 (43% produtoras de SE, 38 amostras produziram SED (30%, 24 SEB (19%, 8 SEC (6% e 4 SEA (3%. Estes resultados trazem preocupações quanto à saúde pública pela alta prevalência de amostras de S. aureus produtoras de TSST-1 e de enterotoxinas em isolamentos a partir de leite de vacas com mastite.A total of 127 strains of Staphylococcus aureus were examined for the production of toxic shock syndrome toxin (TSST-1 and staphylococcal enterotoxins (SE A, B, C and D. The strains were isolated from milk samples from cows with mastitis in dairy herds of Minas Gerais State, Brazil, from 1994 to 1997. The toxins were detected using the optimum-sensitivity plate method. Of 127 isolates, 60 (47% produced TSST-1 and 54 (43% produced SE, 38 (30% produced SED, 24 (19% SEB, 8 (6% SEC and 4 (3% enterotoxin A..

  5. 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.

  6. Antibacterial activity of eight Iranian plant extracts against methicillin and cefixime restistant Staphylococcous aureus strains

    Institute of Scientific and Technical Information of China (English)

    Morteza Shojaei Moghadam; Susan Maleki; Esmaeil Darabpour; Hossein Motamedi; Seyyed Mansour Seyyed Nejad

    2010-01-01

    Objective:To assess the antibacterial activity of eight Iranian plant extracts against Staphylococcus aureus (S. aureus)strains which were isolated from infected patients.Methods:The studied strains were isolated from urine, stool, blood and wound of infected patients and identified by biochemical tests. In further, the antibacterial activity of 8 ethanolic local plant extracts includingQuerqus brantii (Q. brantii),Ziziphus spina-christi (Z. spina-christi),Peganum harmala(P. harmala),Oliveira decumbens (O. decumbens),Galium tricornutum(G. tricornutum), Vitex pseudonegundo (Vi. pseudo negundo),Salvia officinalis (S. officinalis) ,Vaccaria pyramidata (V.pyramidata)were then evaluated using agar disc diffusion method.Results:A total of 9 isolates were isolated and identified asS. aureus. Antibacterial profile of the strains showed that the strains were resistant to methicillin and cefixime. The highest antibacterial activity against the studied strains were belong toQ. brantii,P. harmala,Z. spina-christi andO. decumbens vent extracts with 11-40 mm, 15-28 mm, 8-26 mm and 10-20 mm of diameters, respectively. Intermediate antibacterial activity was exhibited byG. tricornutum andVi. pseudo negundo against some of the studied strains with 7-20 mm and 7-13 mm of diameters, respectively. Noteworthy, out of 9 studied strains; 6 and 2 of them were resistant to theG. tricornutum andVi. pseudo negundo extracts, respectively. TheS. officinalis andVa. pyramidata, however, showed no antibacterial activity against the studied strains.Conclusions: TheQ. brantii,P. harmala,Z. spina-christi andO. decumbens extracts were shown to possess strong antibacterial activity against methicillin and cefixime resistant S. aureus strains and can be considered as the promising natural antibiotics for treating the studied strains.

  7. Impact of strain typing methods on assessment of relationship between paired nares and wound isolates of methicillin-resistant Staphylococcus aureus

    NARCIS (Netherlands)

    J.E. Clarridge III (Jill); R.A. Harrington (Robert Alex); M.C. Roberts (Marilyn); O.O. Soge (Olusegun); K. Maquelin (Kees)

    2013-01-01

    textabstractThe anterior nares are the site of choice for the Veterans Administration methicillin-resistant Staphylococcus aureus (MRSA) surveillance program; however, a correlation between nares colonization and concomitant wound infections has not been well established. The purpose of this study w

  8. Phenotype, genotype, and antibiotic susceptibility of Swedish and Thai oral isolates of Staphylococcus aureus

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    Susanne Blomqvist

    2015-04-01

    Full Text Available Objective: The present study investigated phenotypes, virulence genotypes, and antibiotic susceptibility of oral Staphylococcus aureus strains in order to get more information on whether oral infections with this bacterium are associated with certain subtypes or related to an over-growth of the S. aureus variants normally found in the oral cavity of healthy carriers. Materials and methods: A total number of 157 S. aureus strains were investigated. Sixty-two strains were isolated from Swedish adults with oral infections, 25 strains were from saliva of healthy Swedish dental students, and 45 strains were from tongue scrapings of HIV-positive subjects in Thailand, and 25 Thai strains from non-HIV controls. The isolates were tested for coagulase, nitrate, arginine, and hemolysin, and for the presence of the virulence genes: hlg, clfA, can, sdrC, sdrD, sdrE, map/eap (adhesins and sea, seb, sec, tst, eta, etb, pvl (toxins. MIC90 and MIC50 were determined by E-test against penicillin V, oxacillin, amoxicillin, clindamycin, vancomycin, fusidic acid, and cefoxitin. Results: While the hemolytic phenotype was significantly (p<0.001 more common among the Thai strains compared to Swedish strains, the virulence genes were found in a similar frequency in the S. aureus strains isolated from all four subject groups. The Panton-Valentine leukocidin (PVL genotype was found in 73–100% of the strains. More than 10% of the strains from Swedish oral infections and from Thai HIV-positives showed low antibiotic susceptibility, most commonly for clindamycin. Only three methicillin-resistant S. aureus (MRSA strains were identified, two from oral infections and one from a Thai HIV patient. Conclusions: S. aureus is occasionally occurring in the oral cavity in both health and disease in Sweden and Thailand. It is therefore most likely that S. aureus in opportunistic oral infections originate from the oral microbiota. S. aureus should be considered in case of oral

  9. Proteomic Characterization of Lytic Bacteriophages of Staphylococcus aureus Isolated from Sewage Affluent of India

    Science.gov (United States)

    Sangha, Kamalpreet Kaur; Kumar, B. V. Sunil; Agrawal, Ravi Kant; Verma, Ramneek

    2014-01-01

    Staphylococcus aureus is a Gram-positive bacterium that causes a variety of diseases, including bovine mastitis, which has severe economic consequences. Standard antibiotic treatment results in selection of resistant strains, leading to need for an alternative treatment such as bacteriophage therapy. Present study describes isolation and characterization of a staphylococcal phage from sewage samples. S. aureus isolates obtained from microbial type culture collection (MTCC), Chandigarh, India, were used to screen staphylococcal phages. A phage designated as ΦMSP was isolated from sewage samples by soft agar overlay method. It produced clear plaques on tryptone soya agar overlaid with S. aureus. Transmission electron microscopy revealed that the phage had an icosahedral symmetry. It had 5 major proteins and possessed a peptidoglycan hydrolase corresponding to 70 kDa. ΦMSP infection induced 26 proteins to be uniquely expressed in S. aureus. This phage can be proposed as a candidate phage to treat staphylococcal infections. PMID:27355013

  10. Strain Discrimination of Staphylococcus aureus Using Superantigen Profiles.

    Science.gov (United States)

    Tsen, Hau-Yang; Li, Sheng-Chih; Chiang, Yu-Cheng; Tsai, Shuo-Wen

    2016-01-01

    Staphylococcus aureus is one of the major bacterial species that may cause clinical infection and food-poisoning cases. Strains of this species may produce a series of superantigens (SAgs). Due to the importance of staphylococcal infections, reliable methods for the discrimination of strains of this species are important. Such data may allow us to trace the infection origins and be used for epidemiological study. For strain discrimination, genotyping methods, such as pulsed-field gel electrophoresis (PFGE), random amplified polymorphic DNA (RAPD), and multi-locus sequence typing (MLST), etc., could be used. Recently, toxin gene profiles, which can be used for the elucidation of the genetic and pathogenic relatedness between strains, also have been used to improve the strain discrimination. For S. aureus, as more SAg genes were discovered, the SAg profiles become more useful for the strain discrimination of S. aureus. In this chapter, a method for the discrimination of S. aureus strains using superantigen profiles will be described in detail.

  11. 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.

  12. Clonal profile, virulence and resistance of Staphylococcus aureus isolated from sheep milk

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    Katheryne Benini Martins

    2015-06-01

    Full Text Available 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.

  13. Genotypes and toxin gene profiles of Staphylococcus aureus clinical isolates from China.

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    Yanping Xie

    Full Text Available A total of 108 S. aureus isolates from 16 major hospitals located in 14 different provinces in China were characterized for the profiles of 18 staphylococcal enterotoxin (SE genes, 3 exfoliatin genes (eta, etb and etd, and the toxic shock syndrome toxin gene (tsst by PCR. The genomic diversity of each isolate was also evaluated by pulsed-field gel electrophoresis (PFGE, multilocus sequence typing (MLST, and accessory gene regulator (agr typing. Of these strains, 90.7% (98/108 harbored toxin genes, in which tsst was the most prevalent toxin gene (48.1%, followed by sea (44.4%, sek (42.6% and seq (40.7%. The see and etb genes were not found in any of the isolates tested. Because of high-frequency transfer of toxin gene-containing mobile genetic elements between S. aureus strains, a total of 47 different toxin gene combinations were detected, including a complete egc cluster in 19 isolates, co-occurrence of sea, sek and seq in 38 strains, and sec and sel together in 11 strains. Genetic typing by PFGE grouped all the strains into 25 clusters based on 80% similarity. MLST revealed 25 sequence types (ST which were assigned into 16 clonal complexes (CCs including 2 new singletons. Among these, 11 new and 6 known STs were first reported in the S. aureus strains from China. Overall, the genotyping results showed high genetic diversity of the strains regardless of their geographical distributions, and no strong correlation between genetic background and toxin genotypes of the strains. For genotyping S. aureus, PFGE appears to be more discriminatory than MLST. However, toxin gene typing combined with PFGE or MLST could increase the discriminatory power of genotyping S. aureus strains.

  14. PCR-based identification of methicillin-resistant Staphylococcus aureus strains and their antibiotic resistance profiles

    Institute of Scientific and Technical Information of China (English)

    Abazar Pournajaf; Abdollah Ardebili; Leyla Goudarzi; Mahmoud Khodabandeh; Tahmineh Narimani; Hassan Abbaszadeh

    2014-01-01

    Objective: To evaluated the PCR for mecA gene compared with the conventional oxacillin disk diffusion method for methicillin-resistant Staphylococcus aureus (S. aureus) identification. Methods: A total of 292 S. aureus strains were isolated from various clinical specimens obtained from hospitalized patients. Susceptibility test to several antimicrobial agents was performed by disk diffusion agar according to Clinical and Laboratory Standards Institute guidelines. The PCR amplification of the mecA gene was carried out in all the clinical isolates.Results:activity and vancomycin was the most effective. The rate of methicillin-resistant S. aureus prevalence determined by oxacillin disk diffusion method was 47.6%; whereas, 45.1% of S. aureus isolates were mecA- positive in the PCR assay. Among antibiotics used in our study, penicillin showed the least anti-staphylococcal Conclusions: This study is suggestive that the PCR for detection of mecA gene is a fast, accurate and valuable diagnostic tool, particularly in hospitals in areas where methicillin-resistant S. aureus is endemic.

  15. Characterization of Toxin Genes and Antimicrobial Susceptibility of Staphylococcus aureus Isolates in Fishery Products in Iran

    Science.gov (United States)

    Arfatahery, Noushin; Davoodabadi, Abolfazl; Abedimohtasab, Taranehpeimaneh

    2016-01-01

    Staphylococcus aureus is one of the most common causes of seafood-borne diseases worldwide, which are attributable to the contamination of food by preformed enterotoxins. In this study, a total of 206 (34.3%) Staphylococcus aureus strains were obtained from 600 fish and shrimp samples and were tested for their antimicrobial susceptibility. We assessed the prevalence of the genes responsible for the staphylococcal enterotoxins (SEA, SEB) and toxic shock syndrome toxin 1 (TSST-1) genes. The results indicated that 34% of aqua food samples were contaminated with S. aureus, and 23.8% of these isolates were mec-A-positive. Sixty-four percent of the strains isolated from contaminated seafood was enterotoxigenic S. aureus, and 28.2% of SEs were MRSA-positive. The most prevalent genotype was characterized by the presence of the sea gene (45.2%), followed by the seb gene (18.5%), and the tst gene encoding TSST-1 was found in eight strains (3.9%). Of the 206 S. aureus isolates, 189 strains (84.9%) were resistant to at least one antibiotic. Given the frequent outbreaks of enterotoxigenic MRSA, it is necessary to make revisions to mandatory programmes to facilitate improved hygiene practices during fishing, aquaculture, processing, and sales to prevent the contamination of fishery products in Iran. PMID:27694813

  16. The Frequency of Staphylococcus aureus Isolated from Endocervix of Infertile Women in Northwest Iran

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    Akhi Mohammad Taghi

    2017-01-01

    Full Text Available Background Infertility is one of the major social issues. Due to the asymptomatic cervical infection associated with Staphylococcus aureus (S. aureus, the majority of patients remain undiagnosed. The present study intended to assess the frequency of S. aureus isolated from infertile women’s endocervix in northwest Iran. Materials and Methods In a descriptive cross sectional study, specimens were randomly collected during vagina examination using a sterile speculum and swabbing. After performance of antibiotic susceptibility testing, polymerase chain reaction (PCR was used to identify methicillin-resistance S. aureus (MRSA and toxic shock syndrome toxin-1 (TSST-1. Results About 26 (26% and 9 (9% women’s urogenital tracts were colonized by S. aureus and Candida spp., respectively, of which three (11.5% patients were infected with fungi and S. aureus, simultaneously. Antibiotic susceptibility results showed high activity of vancomycin and co-trimoxazole on isolates. Regarding PCR results, mecA sequences were detected in 7 (26.9% strains, whilst the tst gene encoding TSST-1 was not detected in any of clinical strains. Conclusion The prevalence of S. aureus was very high in infertile women. Therefore, it demands all patients undergoing infertility treatment to be investigated thoroughly for this type of infection.

  17. Detection of enterotoxigenic Staphylococcus aureus isolates in domestic dairy products

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    HR Tavakoli

    2010-12-01

    Full Text Available Background and objectives: Staphylococcus aureusis a one of THE most frequent causes of food poisoning (FP in dairy products. The main etiologic agents of FP are staphylococcal enterotoxins (SE. There are different types of SE; types A (SEA and B (SEB are the most clinically important enterotoxins. Traditional dairy products are still produced in small batches and sold by some vendors without a permit from the Ministry of Health. This study focuses on the molecular and serological detection of enterotoxigenic Staphylococcus aureus SEA and SEB genes and its products, respectively from samples of such traditional products."nMaterials and Methods: 100 samples from dairy products were produced under sterile conditions via traditional methods and were transported to the laboratory. The samples were cultured and identified by routine bacteriological methods. The isolated bacteria were evaluated by PCR tests for detection of the genes encoding SEA and SEB. Subsequently, the ability of these strains to produce enterotoxin was examined by Sac's culture method and was confirmed by Sigel Radial Immounodiffussion (SRID."nResults: The results indicated that 32% of the dairy products were contaminated by S. aureus (cream 18% , cheese 10%, milk 4%. The PCR results showed that 15.6% of the S. aureus isolates possessed the SEA gene, 9.3% had the SEB gene, and 6.2% possessed both genes. The evaluation of enterotoxin production indicated that 80% of SEA and 33% of SEB genes were expressed."nConclusion: Enterotoxins SEA and SEB are heat stable and consequently; heating has no effect on dairy products contaminated by entertoxins. Subsequently, gastritis may occur within several hours after consumption. Our findings suggest that PCR is a rapid, sensitive, specific, and inexpensive method for detecting SE and can replace the traditional assays.

  18. Prevalence, toxin gene profiles, and antimicrobial resistance of Staphylococcus aureus isolated from quick-frozen dumplings.

    Science.gov (United States)

    Hao, Dan; Xing, Xiaonan; Li, Guanghui; Wang, Xin; Zhang, Min; Zhang, Weisong; Xia, Xiaodong; Meng, Jianghong

    2015-01-01

    The aim of this study was to investigate the prevalence of Staphylococcus aureus in quick-frozen dumplings and to characterize these strains. A total of 120 dumpling samples, including lamb (n = 13), vegetarian (n = 14), seafood (n = 12), and pork (n = 81) stuffing, were collected in Shaanxi province in China and screened for S. aureus. All S. aureus isolates were characterized by antimicrobial susceptibility testing, and detection of genes encoding staphylococcal enterotoxins, exfoliative toxins A and B (eta and etb), toxic shock syndrome toxin 1 (tsst-1), and resistance to methicillin-oxacillin (mecA). In all, 60.0% of all samples were positive for S. aureus, and 117 S. aureus isolates, including seven mecA-positive strains, were recovered from these positive samples. In addition, all mecA-positive S. aureus isolates were recovered from products of animal origin. In these S. aureus isolates, resistance was observed most frequently to ampicillin (92.3%) and penicillin (86.3%), followed by clarithromycin, erythromycin, midecamycin, tetracycline, and kanahemycin (from 53.8 to 28.2%). All isolates were sensitive to cefoperazone, minocycline, vancomycin, and ofloxacin. The predominant toxin gene was sec (38.5%), followed by seg (19.7%), sej (16.2%), see (12.8%), sea (11.1%), and seb (10.3%), whereas eta, etb, and tsst-1 genes were not detected. These findings indicate that S. aureus was present commonly in quick-frozen dumplings, accompanied by multiple antimicrobial resistance and toxin genes. Our findings highlight the urgency for stricter hygiene strategies in food production and the prudent use of antibiotics in the breeding industry.

  19. Determining of antibiotic resistance profile inStaphylococcus aureus isolates

    Institute of Scientific and Technical Information of China (English)

    Hossein Motamedi; Hadis Mirzabeigi; Tahere Shirali

    2010-01-01

    Objective:To determine the pattern of antibiotic resistance amongStaphylococcus aureus (S. aureus) isolates from clinical specimens and to identify community-acquired methicillin-resistantStaphylococcus aureus(CA-MRSA)in specimens that have been collected from patients referring to one of the hospitals of Ahvaz.Methods:S. aureus isolates from a hospital in Ahvaz were screened for resistance to various antibiotics including methicillin. The susceptibility of the isolates was determined by Kirby-Bauer disc diffusion method. TheMRSA was also treated with ethidium bromide to find the origin of resistance.Results: Among the bacterial isolates, all of 11S. aureus were resistant to methicillin and cefixime,2 were resistant to ciprofloxacine,6 were resistant to tetracycline and the reminder were sensitive or intermediate to other antibiotics. The treated isolates were reminded resistant to methicillin and this suggested that the plasmid was not the origin of resistance in these isolates.Conclusions: These results showed that infection due toMRSA is widespread in Ahvaz and with respect to the spread of vancomycin resistance among MRSA and appearance of overwhelming infections. It is necessary to identify continuously the profile of antibiotic resistance amongS. aureus isolates in other regions and finding appropriate antibiotic for infection control and eradication.

  20. Antibiotic Resistance in Staphylococcus aureus and Coagulase Negative Staphylococci Isolated from Goats with Subclinical Mastitis

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    Salvatore Virdis

    2010-01-01

    Full Text Available Antimicrobial resistance patterns and gene coding for methicillin resistance (mecA were determined in 25 S. aureus and 75 Coagulase Negative Staphylococci (CNS strains isolates from half-udder milk samples collected from goats with subclinical mastitis. Fourteen (56.0% S. aureus and thirty-one (41.3% CNS isolates were resistant to one or more antimicrobial agents. S. aureus showed the highest resistance rate against kanamycin (28.0%, oxytetracycline (16.0%, and ampicillin (12.0%. The CNS tested were more frequently resistant to ampicillin (36.0% and kanamycin (6.7%. Multiple antimicrobial resistance was observed in eight isolates, and one Staphylococcus epidermidis was found to be resistant to six antibiotics. The mecA gene was not found in any of the tested isolates. Single resistance against β-lactamics or aminoglicosides is the most common trait observed while multiresistance is less frequent.

  1. Antimicrobial Resistance and Molecular Characteristics of Nasal Staphylococcus aureus Isolates From Newly Admitted Inpatients.

    Science.gov (United States)

    Chen, Xu; Sun, Kangde; Dong, Danfeng; Luo, Qingqiong; Peng, Yibing; Chen, Fuxiang

    2016-05-01

    Staphylococcus aureus, or methicillin-resistant S. aureus (MRSA), is a significant pathogen in both nosocomial and community infections. Community-associated MRSA (CA-MRSA) strains tend to be multi-drug resistant and to invade hospital settings. This study aimed to assess the antimicrobial resistance and molecular characteristicsof nasal S. aureus among newlyadmitted inpatients.In the present study, 66 S. aureus isolates, including 10 healthcare-associated MRSA (HA-MRSA), 8 CA-MRSA, and 48 methicillin-sensitive S. aureus (MSSA) strains, were found in the nasal cavities of 62 patients by screening 292 newlyadmitted patients. Antimicrobial resistance and molecular characteristics of these isolates, including spa-type, sequence type (ST) and SCCmec type, were investigated. All isolates were sensitive to linezolid, teicoplanin, and quinupristin/dalfopristin, but high levels of resistance to penicillin and erythromycin were detected. According to D-test and erm gene detection results, the cMLS(B) and iMLS(B) phenotypes were detected in 24 and 16 isolates, respectively. All 10 HA-MRSA strains displayed the cMLS(B) phenotypemediated by ermA or ermA/ermC, while the cMLS(B) CA-MRSA and MSSA strains carried the ermB gene. Molecular characterization revealedall 10 HA-MRSA strains were derived from the ST239-SCCmec III clone, and four out of eight CA-MRSA strains were t437-ST59-SCCmec V. The results suggest that patients play an indispensable role in transmitting epidemic CA-MRSA and HA-MRSA strains.

  2. Genotypes and enterotoxin gene profiles of Staphylococcus aureus clinical isolates from China

    Science.gov (United States)

    A total of 108 S. aureus isolates from 16 hospitals located in 14 different provinces in China were characterized for the profiles of 19 staphylococcal enterotoxin (SE) genes by PCR and genotyped by PFGE and MLST. Of these strains, 88.9% (96/108) harbored SE genes, in which tsst was the most prevale...

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

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    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.

  4. Antimicrobial susceptibility pattern of Staphylococcus aureus isolated from clinical specimens in Northern area of Jordan

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    Mazhar Salim Al Zoubi

    2015-12-01

    Full Text Available Background and Objectives: The global spread of methicillin resistant Staphylococcus aureus (MRSA constitutes one of the most serious contemporary challenges to the treatment of hospital-acquired infections. We aimed to screen and assess the antibiotic susceptibility pattern of Staphylococcus aureus isolated from clinical specimens in local hospitals of Northern province in Jordan.Materials and Methods: Staphylococcus aureus was isolated and identified using standard methods from various clinical specimens of different infected body sites from 358 patients during the period from January 2005 to November 2008.Results: Our analysis showed that 31.6% of S. aureus infections were MRSA, while 31% were multidrug resistance (MDR and 42.7% were Oxacillin-resistant (ORSA. Most of these strains were isolated from wound specimens. All isolates were susceptible to vancomycin (100%. They were also susceptible to chloramphenicol, linezolid, nitrofurantoin, rifampicin and teicoplanin (>80%, but showed resistance to erythromycin and penicillin.Conclusion: Vancomycin was the most effective antimicrobial agent against S. aureus. We recommend regular surveillance of hospital associated infections and monitoring antibiotic sensitivity pattern and strict drug policy for antibiotics used within and outside the hospital environments. Keywords: Staphylococcus aureus, MRSA, MDR

  5. Molecular Typing of Mastitis-Causing Staphylococcus aureus Isolated from Heifers and Cows

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    Juliana Rodrigues Pozzi Arcaro

    2013-02-01

    Full Text Available Staphylococcus aureus is among the main etiologic agents of bovine mastitis. A total of 83 isolates of S. aureus from mammary glands of primiparous heifers were collected in the prepartum, calving and during lactation. For lactating cows, a total of 27 isolates of S. aureus from mammary glands were collected during lactation. The samples were taken in two dairy farms located in Sao Paulo State, Brazil. The highest frequency of S. aureus isolation in heifers was at the end of lactation. Strains were typified through Pulsed-field gel electrophoresis (PFGE and grouped according to patterns of restriction enzyme SmaI. PFGE generated seven clonal profiles that were grouped into three different lineages, with the LA lineage being predominant and identified in heifers, as well as in the cows from the two regions studied. It was concluded that the cows showed a significant source of dispersion of S. aureus. At the first lactation the heifers were infected by the same clonal profiles of S. aureus which were isolated from multiparous lactating cows. The heifers were infected during milking over the months of lactation.

  6. Aminoglycosides resistance in clinical isolates of Staphylococcus aureus from a University Hospital in Bialystok, Poland.

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    Katarzyna Kaczyńska

    2008-06-01

    Full Text Available Staphylococcus aureus obtained from a University Hospital in Poland were characterized in relation to resistance to aminoglycoside antibiotics and the distribution of the genes encoding the most clinically relevant aminoglycoside modifying enzymes (AMEs. Of a total of 118 S. aureus, 45 (38.1% isolates were found to be resistant to at least one of the tested antibiotics. All aminoglycoside resistant isolates except one 44 (97.8% were resistant to kanamycin. The majority of strains 37 (82.2% and 32 (71.1% expressed resistance to neomycin and tobramycin, respectively. Eleven strains (24.4% were resistant to gentamicin or amikacin. All S. aureus strains were sensitive to netilmicin. The most prevalent resistance gene was aac(6'-Ie+aph(2' found in 13 (28.9% strains and 12 (26.7% isolates carried ant(4'-Ia gene, whilst aph(3'-IIIa gene was detected in only 7 (15.6% isolates. Additionally, the ant(6-Ia and str genes were detected in 14 (31.1% and 2 (4.4% strains, respectively. Ten (22.2% strains resistant to amikacin, tobramycin, kanamycin or neomycin did not harbor any of the above-noted genes.

  7. Bacillus licheniformis isolated from Korean traditional food sources enhances the resistance of Caenorhabditis elegans to infection by Staphylococcus aureus.

    Science.gov (United States)

    Yun, Hyun Sun; Heo, Ju Hee; Son, Seok Jun; Park, Mi Ri; Oh, Sangnam; Song, Min-Ho; Kim, Jong Nam; Go, Gwang-Woong; Cho, Ho-Seong; Choi, Nag-Jin; Jo, Seung-Wha; Jeong, Do-Youn; Kim, Younghoon

    2014-08-01

    We investigated whether Bacillus spp., newly isolated from Korean traditional food resources, influence the resistance of hosts to foodborne pathogens, by using Caenorhabditis elegans as a surrogate host model. Initially, we selected 20 Bacillus spp. that possess antimicrobial activity against various foodborne pathogens, including Staphylococcus aureus. Among the selected strains, six strains of Bacillus spp. used in preconditioning significantly prolonged the survival of nematodes exposed to S. aureus. Based on 16S rRNA gene sequencing, all six strains were identified as B. licheniformis. Our findings suggest that preconditioning with B. licheniformis may modulate the host defense response against S. aureus.

  8. In vitro characterization of representative clinical South African Staphylococcus aureus isolates from various clonal lineages

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    W.F. Oosthuysen

    2014-07-01

    Full Text Available Data concerning the virulence and pathogenesis of South African strains of Staphylococcus aureus are limited. We investigated host–pathogen interactions of randomly selected clinical S. aureus isolates representing various clones. We characterized the ability of isolates to adhere to fibronectin, fibrinogen, collagens IV and VI, to invade host cells and to induce cell death in vitro. We analysed the possible association of these results with characteristics such as methicillin resistance, Panton–Valentine leucocidin (PVL positivity and clonality. The S. aureus isolates displayed diversity in their abilities to adhere to various human ligands. All isolates were highly invasive except for ST121. PVL-negative isolates were significantly more invasive than the PVL-positive isolates (p 0.004. Isolates of CC5, CC30 and CC121 were non-cytotoxic, whereas isolates of CC22, CC8, CC15, CC45 and CC88 were very cytotoxic. No statistical association was identified between cell death and methicillin resistance, bacterial PVL status, clonality or patient HIV status. The vast majority of isolates were invasive and induced significant cell death. PVL-negative isolates were more invasive than PVL-positive isolates, while methicillin-resistant isolates were not found to be more invasive or cytotoxic than methicillin-susceptible isolates.

  9. Antimicrobial Resistance Analysis and Detection of Methicillin-Resistant Staphylococcus aureus (MRSA)Among Staphylococcus aureus Strains Isolated from Bovine Mastitis%牛源金黄色葡萄球菌的耐药性及耐甲氧西林金黄色葡萄球菌的检测

    Institute of Scientific and Technical Information of China (English)

    苏洋; 蒲万霞; 陈智华; 邓海平

    2012-01-01

    [目的]了解内蒙古地区奶牛乳房炎金黄色葡萄球菌耐药性和耐甲氧西林金黄色葡萄球菌(MRSA)感染的情况,为奶牛乳房炎的防治提供理论依据.[方法]采用K-B纸片扩散法,检测分离自内蒙古地区38株金黄色葡萄球菌对17种药物的敏感性,同时用琼脂稀释法检测苯唑西林、万古霉素对金黄色葡萄球菌的最小抑菌浓度(MIC);再用头孢西丁、苯唑西林纸片扩散法、苯唑西林盐琼脂筛选法和PCR方法扩增mecA耐药基因对分离菌株进行全面MRSA检测.[结果]分离菌株对每种抗生素都有不同程度抗性,对氨苄西林、头孢拉丁、青霉素、复方新诺明、新生霉素和链霉素的耐药率都高于45%,而对氧氟沙星、丁胺卡那霉素、万古霉素、环丙沙星、庆大霉素和头孢唑林的敏感性高于90%,2株细菌的万古霉素MIC≥16 μg.mL-1;其中8株细菌的苯唑西林MIC≥8μg·mL-1,而其它菌株的苯唑西林MIC≤2μg·mL-1,分离菌株多重耐药情况严重,耐受3种及3种以上药物的菌株占84.21%,其中4株细菌能同时耐受9种不同抗菌药物;16 (42.11%)株细菌被检测携带mecA耐药基因,而仅有其中7株的苯唑西林MIC≥4 μg·mL-1;头孢西丁、苯唑西林纸片扩散法和苯唑西林盐琼脂筛选法分别检出7株、10株和7株表型为MRSA的菌株.[结论]分离菌株的耐药性和多重耐药现象较为严重,被调查地区奶牛场中已经存在MRSA和OS-MRSA感染情况,且感染率高.%[Objective] The aim of the study is to investigate the antimicrobial resistance of S. aureus (Science) and to detect the presence of methicillin-resistant S. aureus (MRSA) among S. aureus strains isolated from bovine mastitis in Inner Mongolia, and to provide credible theory evidence for prevention and treatment of bovine mastitis. [Method] K-B.disk diffusion method was used to test drug sensitivity of 38 total strains of S.aureus to 17 commonly used antibiotics

  10. Sequence diversities of serine-aspartate repeat genes among Staphylococcus aureus isolates from different hosts presumably by horizontal gene transfer.

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    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

  11. Antibacterial potential of some plants of traditional use in India against pathogenic strains of S. aureus

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    Abdul Viqar Khan

    2015-03-01

    Full Text Available Objective: To evaluate antibacterial sensitivity of 43 ethnomedicinally important plants belonging to 25 different families from Western Uttar Pradesh, a northern province in India, against hospital isolated pathogenic strains of Staphylococcus aureus (S. aureus. Methods: Methanol (MeOH and aqueous extracts of plants were subjected to sensitivity test against S. aureus ATCC 25953 and two hospital isolated virulent strains of S. aureus SA1 and SA2 following disc diffusion assay to determine sensitivity and agar dilution method to test minimum inhibition concentration using Mueller-Hinton agar. Results: Potential antibacterial activity was recorded for MeOH extracts against test pathogens, while moderate antibacterial activity was observed in case of aqueous extracts. Out of 43 plant species, 39 species were found sensitive to tested strains. Minimum inhibition concentration values of MeOH extracts were demonstrated at low concentration ranging from 15.5 mg/mL up to 45.5 mg/mL compared to aqueous extracts which were observed ranging from 30.0 mg/ mL up to 95.0 mg/mL. Conclusions: The present findings strongly support traditional uses of these plants in the treatment of infectious maladies and further urge of phytochemical and pharmacological research to develop safer and cheaper drugs for the benefit of ailing humanity.

  12. Methods of detection and typing of methicillin resistant Staphylococcus aureus isolated from animals

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    Radosavljević V.

    2014-01-01

    Full Text Available In this work there was evaluated the method of detection of methicillin resistant Staphylococcus aureus (MRSA by using two molecular and three phenotypic tests in investigation procedure of 70 strains of S.aureus isolated from animals. Recent findings of the new mecA homologue, mecALGA251, minimise the significance of mecA gene presence detection as a confirmation method of methicillin resistant Staphylococcus aureus identification. For this reason, along with multiplex PCR set of primers(165rDNK, nuc, mecA for detection mecA gene, there was also used multiplex PCR set of primers (spa, mecA, pvl, mecALGA251 for differentiation mecALGA251 from mecA, with simultaneous detection of luk-PV and spa gene fragments. In all 70 investigated isolates there was detected the presence of specific 16 SrDNK fragment and nuc gene which encodes a thermostable S. aureus nuclease, while in 5 out of 70 S. aureus isolates, there was proven mecA gene presence using two multiplex PCR tests. In the investigated strains there was determined neither mecC (mecALGA251gene presence, nor Panton Valentine Leukocidin encoding gene. By application cefoxitin disk-diffusion, latex-agglutination and two multiplex PCR tests, the identical results in identification 5 methicillin resistant out of 70 investigated S. aureus strains were obtained. In our investigation there was determined a complete correlation between the results of phenotypic and genotypic identification of methicillin resistant S. aureus. [Projekat Ministarstva nauke Republike Srbije, br. TR 31079

  13. Antimicrobial activity of some sulfonamide derivatives on clinical isolates of Staphylococus aureus

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    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. Draft Genome Sequences of Staphylococcus aureus AMRF1 (ST22) and AMRF2 (ST672), Ocular Methicillin-Resistant Isolates

    KAUST Repository

    Velusamy, Nithya

    2014-03-20

    Sequence type 22 (ST22) and ST672 are the two major emerging clones of community-acquired methicillin-resistant Staphylococcus aureus in India. ST672 strains were found to cause severe ocular infections. We report the draft genome sequences of two emerging strains of methicillin-resistant S. aureus, AMRF1 (ST22) and AMRF2 (ST672), isolated from patients with ocular infections.

  15. Duplex real-time PCR assay for rapid identification of Staphylococcus aureus isolates from dairy cow milk.

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    Pilla, Rachel; Snel, Gustavo G M; Malvisi, Michela; Piccinini, Renata

    2013-05-01

    Staphylococcus aureus isolates from dairy cow mastitis are not always consistent with the characteristic morphology described, and molecular investigation is often needed. The aim of the study was to develop a duplex real-time PCR assay for rapid identification of Staph. aureus isolates, targeting both nuc and Sa442. Overall, 140 isolates collected from dairy cow mastitis in 90 different herds, were tested. All strains had been identified using morphological and biochemical characteristics. DNA from each strain was amplified in real-time PCR assay, to detect nuc or Sa442. Thereafter, a duplex real-time PCR assay was performed, and specificity of the amplified products was assessed by high resolution melting curve analysis. Out of 124 Staph. aureus isolates, 33 did not show the typical morphology or enzymic activity; in 118 strains, the two melt-curve peaks consistent with nuc and Sa442 were revealed, while 2 isolates showed only the peak consistent with Sa442. Four isolates bacteriologically identified as Staph. aureus, were PCR-negative and were further identified as Staph. pseudintermedius by sequencing. Staph. pseudintermedius and coagulase-negative staphylococci did not carry nuc or Sa442. The results showed the correct identification of all isolates, comprehending also coagulase-or nuc-negative Staph. aureus, while other coagulase-positive Staphylococci were correctly identified as non-Staph. aureus. Both sensitivity and specificity were 100%. High resolution melting analysis allowed easy detection of unspecific products. Finally, the duplex real-time PCR was applied directly to 40 milk samples, to detect infected mammary quarters. The assay confirmed the results of bacteriological analysis, on Staph. aureus-positive or-negative samples. Therefore, the proposed duplex real-time PCR could be used in laboratory routine as a cost-effective and powerful tool for high-throughput identification of atypical Staph. aureus isolates causing dairy cow mastitis. Also, it

  16. Characterization of SCCmec types, antibiotic resistance, and toxin gene profiles of Staphylococcus aureus strains.

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    Szczuka, Ewa; Grabska, Katarzyna; Trawczyński, Krzysztof; Bosacka, Karolina; Kaznowski, Adam

    2013-09-01

    Methicillin-resistant Staphylococcus aureus (MRSA) causes serious nosocomial and community acquired infections. Resistance to methicillin is mediated by the mecA gene, which is inserted in a mobile genetic element called staphylococcal cassette chromosome mec (SCCmec). We determined the SCCmec types, the occurrence of genes encoding toxic shock syndrome toxin (tst), exfoliative toxin (eta, etb), Panton-Valentine leukocidin (pvl) as well as antibiotic susceptibility of these isolates. Among 65 hospital-acquired methicillin-resistant S. aureus (HA-MRSA) strains, SCCmec types II, III and IV were identified. Type III SCCmec was the most prevalent (62%), followed by mec types II (24%) and IV (14%). Four community acquired methicillin-resistant S. aureus (CA-MRSA) strains carried SCCmec type IV and were pvl-positive. The most prevalent gene among HA-MRSA was pvl. The toxic shock syndrome toxin and exfoliative toxin genes were found only in hospital-acquired methicillin-resistant S. aureus. The results of this study demonstrate that the SCCmec type III is predominant among strains recovered from hospitalized patients with infections and that these strains were resistant to many antibiotics used in the treatment of staphylococcal infections.

  17. Isolation and Identification of Staphylococcus aureus in Raw Milk and Rapid Detection of Toxigenic Strains%原料奶中金黄色葡萄球菌分离鉴定及产毒菌株的快速检测

    Institute of Scientific and Technical Information of China (English)

    覃艳华; 谢和; 胡萍; 李荔枝

    2011-01-01

    Strains of Staphylococcus aureus were isolated and identified from raw milk by traditional taxonomic identification and polymerase chain reaction (PCR), and their toxin producing ability was detected by mini-VIDAS to study the S. aureus contamination in raw milk. The results showed that S. aureus was the main contamination bacteria, 9 strains of them were positive which detected by miniVIDAS, and the detection rate of toxigenic strains was 12.86% in the 70 strains of S. aureus isolated. The PCR designed targeting the primer of thermonuclease(nuc) gene of S. aureus had coincidence rate of 100% with traditional taxonomic identification, and it had higher specificity and sensitivity.%为了蟹原料奶中产毒型金黄色葡萄球菌的污染情况,采用传统分类学鉴定方法与PCR鉴定方法结令,对原料奶中金黄色葡萄球菌进行分离鉴定,并运用全自动荧光免疫分析仪检测了分离.菌株的产毒情况.结果表明,分离鉴定的70株金黄色葡萄球菌中,mini-VIDAS仪分析为阳性的有9株,产毒型金黄色葡萄球菌的检出率为12.86%,金黄色葡萄球菌为原料奶的主要污染菌之一.针对金黄色葡萄球菌耐热核酸酶基因设计的引物进行的PCR鉴定方法,与传统分类学方法的符合率为100%,并且具有较高的特异性及敏感性.

  18. Inducible clindamycin resistance in Staphylococcus aureus isolates recovered from Mashhad, Iran

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    Najmeh seifi

    2012-06-01

    Full Text Available Background and Objectives: Staphylococcus aureus is an important agent in hospital and community-associated infections, causing high morbidity and mortality. Introduction of the new antimicrobial classes for this pathogen is usually followed by the emergence of resistant strains through multiple mechanisms. For instance, resistance to clindamycin (CLI, can be constitutive or inducible. Inducible clindamycin resistance which may lead to treatment failure can simply be identified by performing D-test. The aim of this study was to determine the prevalence of inducible clindamycin resistance among Staphylococcus aureus isolates by D-test method.Materials and Methods: This was a cross-sectional study conducted on 254 non-duplicated S. aureus isolates in Imam Reza hospital of Mashhad during 2010. Susceptibility to oxacillin, cefoxitin, erythromycin and clindamycin was performed by disk agar diffusion method according to CLSI guidelines and D-shaped clindamycin susceptibility patterns where considered as D-test positive (D+.Results: Of 211 S. aureus isolates 88 (37.82% were methicillin resistant. It was found that of 88 MRSA isolates, 78 (88.63% were erythromycin (ERY resistant and 46 (52.27% were CLI resistant. ERY and CLI resistance in MSSA strains was 21.95% and 11.96% respectively. Inducible clindamycin resistance was detected in 18 (20.45% MRSA isolates. 47(53.40% of MRSA isolates and 9 (7.32% of MSSA showed constitutive MLSB phenotype.Conclusion: In conclusion, we found a high prevalence of inducible clindamycin resistance phenotype in our region. We recommend that whenever clindamycin is intended for S. aureus infections, D-test should be performed to facilitate the optimal treatment of patients.Keywords: Staphylococcus aureus, clindamycin, Inducible resistance

  19. Pathogenic Staphylococcus aureus Isolates from Postoperative Wounds of Hospitalized Patients

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    Smritikana Biswas

    2010-07-01

    Full Text Available Staphylococcus sp., gram positive pyogenic bacteria located on skin, nose etc, secretes toxin that causes toxic shock syndrome, abscess, food poisoning and other infectious diseases. This study was carried out to identify and characterize the type of Staphylococcus sp. bacteria especially Staphylococcus aureus in the pus from postoperative wounds of hospitalized patients. From pus samples collected from twenty-four patients from Kharagpur Hospital, Paschim Medinipur, West Bengal, twenty-eight bacterial isolates were obtained. Among them twenty-five (89.2% were appeared with golden yellow colonies which is usually formed by Staphylococcus aureus. Twenty-three (82.14% of the bacterial isolates were Gram positive. Among them twenty isolates (86.9% were further confirmed to be Staphylococcus aureus by their ability to produce Catalase enzyme (positive in Catalase test and Coagulase enzyme (positive in Coagulase Test. Eighteen (90.00% of these Staphylococcus aureus were found to liquefy gelatin (Gelatin hydrolysis test, were able to hydrolyze urea (Urea hydrolysis test and were also l positive in Mannitol Fermentation Test. But there was no growth found of these isolates on MacConkey Agar, while sixteen isolates (80.00% of Staphylococcus aureus were resistant to penicillin (50µg/ml. Moreover eighteen (90.00% Staphylococcus aureus isolates were able to elaborate Hemolysin (Hemolysis test on Blood Agar media. Hence the bacterial isolates obtained from pus of postoperative wounds were predominantly pathogenic Staphylococcus aureus. So it can be concluded that careful treatment and postoperative measures to be taken to avoid serious health problem that may often be life threatening.

  20. Molecular characterization of methicillin resistant Staphylococcus aureus isolated from hospitals environments and patients in Northern Palestine

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    Ghaleb Adwan

    2015-09-01

    Full Text Available BACKGROUND: Staphylococcus aureus (S. aureus is considered one of the most common pathogen to humans. Infections caused by this mocroorganism can be acquired through both hospital and community settings. This study was carried out to investigate molecular characterization of MRSA strains isolated from the patients and their environment in two hospitals (Rafidia hospital and Thabet hospital inNorthern Palestine, and to determine the clonal identity between these strains and their possible contribution to nosocomial infections.METHODS: Two hundred sixty five swabbed samples were collected from these hospitals, S. aureus was isolated,  antibiotic resistant genes were Panton–Valentin leukocidin (PVL gene were detected and SCCmec and spA were typed by PCR and/or sequencing.RESULTS: The prevalence of MRSA among S. aureus isolates was 29% and 8.2% in Rafidia hospital and Thabet hospital, respectively. All strains resistant to oxacilllin disk were carried mecA gene. Majority of strains (84.6% carried SCCmec type II (n = 11, type IVa and non-typeable were also detected. In addition, PVL was detected in 2 (14.3% clinical strains. ERIC PCR patterns revealed that 2 strains recovered from patient bed and nasal swab isolated from Thabet Hospital were nontypeable, spA typing showed that they belonged to type t386 and have identical DNA sequences. Other 2 clinical isolates were spa typed, one belonged to clone t044, while the other is new clone not exist in database.CONCLUSIONS: Results may give evidence that environmental contamination possibly contributing to nosocomial infections.

  1. 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.

  2. Molecular typing of nosocomial Staphylococcus aureus strains associated to biofilm based on the coagulase and protein A gene polymorphisms

    Science.gov (United States)

    Salehzadeh, Ali; Zamani, Hojjatolah; Langeroudi, Maedeh Keshtkar; Mirzaie, Amir

    2016-01-01

    Objective(s): Staphylococcus aureus is an important bacterial pathogen responsible for a variety numbers of nosocomial and community acquired infections. Biofilm formation is regarded as an important factor in the establishment of S. aureus infection. The contribution of the genetic background of S. aureus to biofilm formation is poorly understood. The aim of the present work was to genotype S. aureus strains associated to biofilm based on the coagulase and protein A genes and to evaluate the association between the genetic background and the biofilm forming ability of clinical S. aureus isolates. Materials and Methods: A total number of 100 S. aureus were isolated from nosocomial infections and biofilm formation capability was investigated using phenotypic assay and molecular detection of biofilm associated genes. The strains were genotyped based on coagulase (coa) and protein A (spa) gene polymorphisms using restriction fragments length polymorphism-polymerase chain reaction (RFLP-PCR). Results: RFLP-PCR of coa gene generated two types and three subtypes. Amplification of spa gene resulted in two banding patterns and their restriction digestion generated three subtypes. The combined coa and spa RFLP patterns generated nine genotypes (G1-G9). The genotypes G4 and G1 were the most prevalent (32.1% and 24.3%, respectively). Conclusion: High clonal diversity of S. aureus strains able to produce biofilm was observed. Biofilm formation correlates with the spa and coa clonal lineage in our population and testing for multiple gene polymorphisms could be employed for local epidemiologic purposes. PMID:28096965

  3. Molecular typing of nosocomial Staphylococcus aureus strains associated to biofilm based on the coagulase and protein A gene polymorphisms

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    Ali Salehzadeh

    2016-12-01

    Full Text Available Objective(s: Staphylococcus aureus is an important bacterial pathogen responsible for a variety numbers of nosocomial and community acquired infections. Biofilm formation is regarded as an important factor in the establishment of S. aureus infection. The contribution of the genetic background of S. aureus to biofilm formation is poorly understood. The aim of the present work was to genotype S. aureus strains associated to biofilm based on the coagulase and protein A genes and to evaluate the association between the genetic background and the biofilm forming ability of clinical S. aureus isolates. Materials and Methods: A total number of 100 S. aureus were isolated from nosocomial infections and biofilm formation capability was investigated using phenotypic assay and molecular detection of biofilm associated genes. The strains were genotyped based on coagulase (coa and protein A (spa gene polymorphisms using restriction fragments length polymorphism-polymerase chain reaction (RFLP-PCR. Results: RFLP-PCR of coa gene generated two types and three subtypes. Amplification of spa gene resulted in two banding patterns and their restriction digestion generated three subtypes. The combined coa and spa RFLP patterns generated nine genotypes (G1-G9. The genotypes G4 and G1 were the most prevalent (32.1% and 24.3%, respectively. Conclusion: High clonal diversity of S. aureus strains able to produce biofilm was observed. Biofilm formation correlates with the spa and coa clonal lineage in our population and testing for multiple gene polymorphisms could be employed for local epidemiologic purposes.

  4. Phenotypic and Genotypic Characterization of Staphylococcus aureus Strains from Italian Dairy Products

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    Stefano Morandi

    2009-01-01

    Full Text Available Staphylococcus aureus is a known major cause of foodborne illnesses, and milk and dairy products are often contaminated by enterotoxigenic strains of this bacterium. In the present study, 122 S. aureus isolates collected from different dairy products were characterised by phenotypic properties, by the distribution of genes encoding staphylococcal enterotoxins (sea, sec, sed, seg, seh, sei, sej, and sel and by randomly amplified polymorphic DNA PCR (RAPD-PCR. Moreover, strain resistance to vancomycin and methicillin (oxacillin was studied. The differences in the RAPD-PCR profiles obtained with the primers M13 and AP4 revealed the presence of a great genetic heterogeneity among the different S. aureus strains. Using the primer AP4 and M13, eight groups were distinguished by RAPD-PCR cluster analysis, although, except in few cases, it was not possible to correlate the isolates of different animal species (cow or ovine with the presence of se genes. None of the isolates showed resistance to vancomycin or methicillin.

  5. Superantigen Profiling of Staphylococcus aureus Infective Endocarditis Isolates

    Science.gov (United States)

    Chung, Jin-Won; Karau, Melissa J.; Greenwood-Quaintance, Kerryl E.; Ballard, Alessandro D.; Tilahun, Ashenafi; Khaleghi, Shahryar Rostamkolaei; David, Chella S.; Patel, Robin; Rajagopalan, Govindarajan

    2014-01-01

    The frequency of superantigen production among Staphylococcus aureus isolates associated with endocarditis is not well defined. We tested 154 S. aureus isolates from definite infective endocarditis cases for the presence of staphylococcal enterotoxins A-E, H and TSST-1 by PCR, ELISA and using an HLA-DR3 transgenic mouse splenocyte proliferation assay. Sixty-three isolates (50.8%) tested positive for at least one superantigen gene, with 21 (16.9%) testing positive for more than two. tst (28.6%) was most common, followed by seb (27%), sea (22.2%), sed (20.6%), see (17.5%), and sec (11.1%). Of 41 methicillin-resistant S. aureus, 21 had superantigen genes, with sed being more frequently detected in this group compared to methicillin-susceptible S. aureus (P<0.05). Superantigen genes were not associated with mortality (P=0.81). 75% of PCR-positive isolates induced robust splenocyte proliferation. Overall, more than half of S. aureus isolates causing endocarditis carry superantigen genes of which most are functional. PMID:24745820

  6. Antibacterial Activity of New Oxazolidin-2-One Analogues in Methicillin-Resistant Staphylococcus aureus Strains

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    Jesús Córdova-Guerrero

    2014-03-01

    Full Text Available Staphylococcus aureus is one of the most common causes of nosocomial infections. The purpose of this study was the synthesis and in vitro evaluation of antimicrobial activity of 10 new 3-oxazolidin-2-one analogues on 12 methicillin resistant S. aureus (MRSA clinical isolates. S. aureus confirmation was achieved via catalase and coagulase test. Molecular characterization of MRSA was performed by amplification of the mecA gene. Antimicrobial susceptibility was evaluated via the Kirby-Bauer disc diffusion susceptibility test protocol, using commonly applied antibiotics and the oxazolidinone analogues. Only (R-5-((S-1-dibenzylaminoethyl-1,3-oxazolidin-2-one (7a exhibited antibacterial activity at 6.6 μg. These results, allow us to infer that molecules such as 7a can be potentially used to treat infections caused by MRSA strains.

  7. Antibacterial Activity of New Oxazolidin-2-One Analogues in Methicillin-Resistant Staphylococcus aureus Strains

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    Córdova-Guerrero, Jesús; Hernández-Guevara, Esteban; Ramírez-Zatarain, Sandy; Núñez-Bautista, Marco; Ochoa-Terán, Adrián; Muñiz-Salazar, Raquel; Montes-Ávila, Julio; López-Angulo, Gabriela; Paniagua-Michel, Armando; Nuño Torres, Gustavo A.

    2014-01-01

    Staphylococcus aureus is one of the most common causes of nosocomial infections. The purpose of this study was the synthesis and in vitro evaluation of antimicrobial activity of 10 new 3-oxazolidin-2-one analogues on 12 methicillin resistant S. aureus (MRSA) clinical isolates. S. aureus confirmation was achieved via catalase and coagulase test. Molecular characterization of MRSA was performed by amplification of the mecA gene. Antimicrobial susceptibility was evaluated via the Kirby-Bauer disc diffusion susceptibility test protocol, using commonly applied antibiotics and the oxazolidinone analogues. Only (R)-5-((S)-1-dibenzylaminoethyl)-1,3-oxazolidin-2-one (7a) exhibited antibacterial activity at 6.6 μg. These results, allow us to infer that molecules such as 7a can be potentially used to treat infections caused by MRSA strains. PMID:24675696

  8. Coagulase gene polymorphism of Staphylococcus aureus isolates: A study on dairy food products and other foods in Tehran, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Soltan Dallal

    2016-12-01

    Full Text Available Coagulase is considered as a major determinant factor for the identification of Staphylococcus aureus strains. The 3′-end coding region of the coagulase (coa gene contains a series of 81-bp tandem repeats, which differ in the number and location of enzymatic restriction sites among different isolates. coa PCR-RFLP has been used widely to type S. aureus isolates in epidemiological studies. The current study was conducted to investigate the coagulase gene polymorphisms in S. aureus isolated from various food samples using an in house PCR-RFLP method. A total of 100 strains of S. aureus were isolated from food samples. Isolates were typed by PCR-RFLP analysis using NdeI restriction digestion of the coagulase gene PCR products. Results showed that amplification of coagulase genes from S. aureus produced different PCR products. The isolates were grouped into 18 genotypes using RFLP analysis results of the genes. In this study, the S. aureus isolates have been shown to include more than one coagulase genotype, but only had a few coa genotypes predominated.

  9. Identification and Characterization of Staphylococcus aureus Strains with an Incomplete Hemolytic Phenotype

    Directory of Open Access Journals (Sweden)

    Haifang Zhang

    2016-11-01

    Full Text Available Staphylococcus aureus is a common pathogen causing both hospital and community-acquired infections. Hemolysin is one of the important virulence factors for S. aureus and causes the typical β-hemolytic phenotype which is called complete hemolytic phenotype as well. Recently, Staphylococcus aureus with an incomplete hemolytic phenotype (SIHP was isolated from clinical samples. To study the microbiologic characteristics of SIHP, SIHP was inoculated on the sheep blood agar plates supplied by different manufacturers to compare their hemolytic phenotype. Expression of hemolysin genes hla, hlb, hlgC and hld of SIHP was detected by qRT-PCR. In addition, the alpha-hemolysin encoded by gene hla was analyzed by western blot. At the same time, the antimicrobial susceptibility of SIHP was tested using the broth dilution method. The main antibiotic resistance gene mecA and virulence genes tst were detected by PCR in SIHP strains. Furthermore, the virulence of SIHP strains was detected through comparing their intracellular survival in macrophage. The cytokines and chemokines secreted by macrophage were measured by flow cytometry. Finally, the genotyping of SIHP was performed by multilocus sequence typing (MLST analysis. The results showed that the incomplete hemolytic phenotype of SIHP could be observed on the sheep blood agar plates from different suppliers. The relative mRNA expression of hlb in SIHP was obviously increased compared to the control Staphylococcus aureus strains, while the expression of hla, hlgC and hld in SIHP was significantly decreased. In addition, it was shown that the alpha-hemolysin of SIHP was less than that of control strains as well. All sixty SIHP strains were identified to be the methicillin resistant Staphylococcus aureus (MRSA, and moreover these SIHP strains all contains mecA gene. The virulence gene tst were all present in SIHP, and the intracellular survival ability of SIHP was much greater than that of the gene tst negative

  10. CHARACTERISATION OF METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS ISOLATES FROM SHINGLES PATIENTS

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    Jasmine R. et al.

    2011-11-01

    Full Text Available Even after treating Shingles patients with antiviral drugs, they are found to suffer from secondary bacterial infections. With this background as a guide, we undertook an investigation to isolate the bacterial pathogens from the pus of Shingles patients. Among the isolates obtained during the one year study period, Staphylococcus aureus sp. was found to be multi drug resistant and hence it was chosen for the study. The antibiogram pattern of the methicillin resistant S. aureus was obtained, since this could serve as a tool for suggesting useful drugs.

  11. Evaluation of the presence of the bap gene in Staphylococcus aureus isolates recovered from human and animals species.

    Science.gov (United States)

    Vautor, E; Abadie, G; Pont, A; Thiery, R

    2008-03-18

    The implication of biofilm in chronic bacterial infection in many species has triggered an increasing interest in the characterization of genes involved in biofilm formation. The bap gene is a newly identified gene that encodes the biofilm-associated protein, BAP, which is involved in biofilm formation in Staphylococcus aureus. So far the bap gene has only been found in a small proportion of S. aureus strains from bovine mastitis in Spain. In order to study the presence of the bap gene in S. aureus isolates obtained from other species and various locations, a collection of 262 isolates was tested by PCR, using published primers and dot-blot. The results indicated that none of the isolates carried the bap gene suggesting that the prevalence of this gene among S. aureus isolates should be very low.

  12. Staphylococcus aureus infective endocarditis versus bacteremia strains: Subtle genetic differences at stake.

    Science.gov (United States)

    Bouchiat, Coralie; Moreau, Karen; Devillard, Sébastien; Rasigade, Jean-Philippe; Mosnier, Amandine; Geissmann, Tom; Bes, Michèle; Tristan, Anne; Lina, Gérard; Laurent, Frédéric; Piroth, Lionel; Aissa, Nejla; Duval, Xavier; Le Moing, Vincent; Vandenesch, François

    2015-12-01

    Infective endocarditis (IE)((1)) is a severe condition complicating 10-25% of Staphylococcus aureus bacteremia. Although host-related IE risk factors have been identified, the involvement of bacterial features in IE complication is still unclear. We characterized strictly defined IE and bacteremia isolates and searched for discriminant features. S. aureus isolates causing community-acquired, definite native-valve IE (n=72) and bacteremia (n=54) were collected prospectively as part of a French multicenter cohort. Phenotypic traits previously reported or hypothesized to be involved in staphylococcal IE pathogenesis were tested. In parallel, the genotypic profiles of all isolates, obtained by microarray, were analyzed by discriminant analysis of principal components (DAPC)((2)). No significant difference was observed between IE and bacteremia strains, regarding either phenotypic or genotypic univariate analyses. However, the multivariate statistical tool DAPC, applied on microarray data, segregated IE and bacteremia isolates: IE isolates were correctly reassigned as such in 80.6% of the cases (C-statistic 0.83, P<0.001). The performance of this model was confirmed with an independent French collection IE and bacteremia isolates (78.8% reassignment, C-statistic 0.65, P<0.01). Finally, a simple linear discriminant function based on a subset of 8 genetic markers retained valuable performance both in study collection (86.1%, P<0.001) and in the independent validation collection (81.8%, P<0.01). We here show that community-acquired IE and bacteremia S. aureus isolates are genetically distinct based on subtle combinations of genetic markers. This finding provides the proof of concept that bacterial characteristics may contribute to the occurrence of IE in patients with S. aureus bacteremia.

  13. Identification of virulence genes carried by bacteriophages obtained from clinically isolated methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Karasartova, Djursun; Cavusoglu, Zeynep Burcin; Turegun, Buse; Ozsan, Murat T; Şahin, Fikret

    2016-12-01

    Bacteriophages play an important role in the pathogenicity of Staphylococcus aureus (S. aureus) either by carrying accessory virulence factors or several superantigens. Despite their importance, there are not many studies showing the actual distribution of the virulence genes carried by the prophages obtained from the clinically isolated Staphylococcus. In this study, we investigated prophages obtained from methicillin-resistant S. aureus (MRSA) strains isolated from hospital- and community-associated (HA-CA) infections for the virulence factors. In the study, 43 phages isolated from 48 MRSA were investigated for carrying toxin genes including the sak, eta, lukF-PV, sea, selp, sek, seg, seq chp, and scn virulence genes using polymerase chain reaction (PCR) and Southern blot. Restriction fragment length polymorphism was used to analyze phage genomes to investigate the relationship between the phage profiles and the toxin genes' presence. MRSA strains isolated from HA infections tended to have higher prophage presence than the MRSA strains obtained from the CA infections (97% and 67%, respectively). The study showed that all the phages with the exception of one phage contained one or more virulence genes in their genomes with different combinations. The most common toxin genes found were sea (83%) followed by sek (77%) and seq (64%). The study indicates that prophages encode a significant proportion of MRSA virulence factors.

  14. Molecular typing of MRSA and of clinical Staphylococcus aureus isolates from Iaşi, Romania.

    Science.gov (United States)

    Monecke, Stefan; Müller, Elke; Dorneanu, Olivia Simona; Vremeră, Teodora; Ehricht, Ralf

    2014-01-01

    Romania is one of the countries with the highest prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in the world. To obtain data on affiliation of MRSA to strains and clonal complexes and on the population of methicillin susceptible S. aureus (MSSA), clinical isolates from bloodstream infections, skin and soft tissue infections as well as from screening swabs were collected at hospitals in Ia?i, a city in the North-Eastern part of Romania. Isolates were characterised by microarray hybridisation. Nearly half of all isolates (47%), and about one third (34%) of bloodstream isolates were MRSA. The prevalence of the Panton-Valentine leukocidin (PVL) was also high (31% among MRSA, 14% among MSSA). The most common MRSA strain was a PVL-negative CC1-MRSA-IV that might have emerged locally, as a related MSSA was also common. PVL-positive CC8-MRSA-IV ("USA300") and PVL-negative ST239-like MRSA-III were also frequently found while other MRSA strains were only sporadically detected. Among MSSA, PVL-positive CC121 as well as PVL-negative CC1, CC22 and CC45 predominated. Although this study provides only a snapshot of S. aureus/MRSA epidemiology in Romania, it confirms the high burden of MRSA and PVL on Romanian healthcare settings.

  15. Superantigens in Staphylococcus aureus isolated from prosthetic joint infection

    Science.gov (United States)

    Kim, Choon K.; Karau, Melissa J.; Greenwood-Quaintance, Kerryl E.; Tilahun, Ashenafi Y.; David, Chella S.; Mandrekar, Jayawant N.; Patel, Robin; Rajagopalan, Govindarajan

    2014-01-01

    Staphylococcus aureus is a common cause of prosthetic joint infection (PJI). The prevalence of superantigens (SAgs) among PJI-associated S. aureus is unknown. Eighty-four S. aureus isolates associated with PJI isolated between 1999 and 2006 were studied. SAg genes, sea, seb, sec, sed, see, seg, seh, sei and tst, were assayed by PCR. Seventy-eight (92.9%) isolates carried at least one SAg gene studied, with 61 (72.6%) harboring more than one. seg was most commonly (70.2%) and seh was least frequently (4.8%) detected. tst-positive isolates were associated with early infection and increased ESR at diagnosis (P = 0.006 and P = 0.021, respectively). seg and sei were associated with methicillin resistance (P = 0.008 and 0.002, respectively). SAg genes are prevalent in S. aureus causing PJI; a majority of PJI-associated isolates produce biologically active SAgs in both planktonic and biofilm growth modes. PMID:25619753

  16. Antibiotic resistance and pathogenicity factors in Staphylococcus aureus isolated from mastitic Sahiwal cattle

    Indian Academy of Sciences (India)

    Ravinder Kumar; B R Yadav; R S Singh

    2011-03-01

    Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious problem in dairy animals suffering from mastitis. In the present study, the distribution of mastitic MRSA and antibiotic resistance was studied in 107 strains of S. aureus isolated from milk samples from 195 infected udders. The characterizations pathogenic factors (adhesin and toxin genes) and antibiotic susceptibility of isolates were carried out using gene amplification and disc diffusion assays, respectively. A high prevalence of MRSA was observed in the tested isolates (13.1%). The isolates were also highly resistant to antibiotics, i.e. 36.4% were resistant to streptomycin, 33.6% to oxytetracycline, 29.9% to gentamicin and 26.2% each to chloramphenicol, pristinomycin and ciprofloxacin. A significant variation in the expression of pathogenic factors (Ig, coa and clf) was observed in these isolates. The overall distribution of adhesin genes ebp, fib, bbp, fnbB, cap5, cap8, map and cna in the isolates was found to be 69.1, 67.2, 6.5, 20.5, 60.7, 26.1, 81.3 and 8.4%, respectively. The presence of fib, fnbB, bbp and map genes was considerably greater in MRSA than in methicillin-susceptible S. aureus (MSSA) isolates. The proportions of toxin genes, namely, hlb, seb, sec, sed, seg and sei, in the isolates were found to be 94.3, 0.9, 8.4, 0.9, 10.2 and 49.5%, respectively. The proportions of agr genes I, II, III and IV were found to be 39.2, 27.1, 21.5 and 12.1%, respectively. A few isolates showed similar antibiotic-resistance patterns, which could be due to identical strains or the dissemination of the same strains among animals. These findings can be utilized in mastitis treatment programmes and antimicrobials strategies in organized herds.

  17. Enterotoxigenicity of Staphylococcus aureus isolated from traditional and commercial dairy products marketed in Iran

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    Ebrahim Rahimi

    2013-01-01

    Full Text Available This study was conducted to determine the prevalence rate, enterotoxigenecity, and antimicrobial resistance of S. aureus isolated from dairy products in Iran. From September 2010 to July 2011, a total of 347 samples from various dairy products, traditional and commercial, were collected from randomly selected retail stores. Overall, 20 samples (5.8% were found to be contaminated with S. aureus. The highest prevalence of S. aureus was found in traditional cheese (11.1%, followed by traditional ice-cream (5.9%, cream (5.6%, and butter (5.3%. The ability to synthesize classical staphylococcal enterotoxins (SEA-E was determined in 7 of 20 (35% isolates by using ELISA. SE type C was the most common enterotoxin found in the isolated S. aureus (42.9%, followed by SE type A (28.6%, SEA+SEC and SE type D (14.3%. Of the 20 isolates, 16 (80.0% were positive for one or more entrotoxin genes and 8 different genotypes were observed. Susceptibilities of the isolates were determined for 14 antimicrobial drugs using the disk diffusion assay. Most of the isolates (95.0% were resistant to one or more two antimicrobial agent and 45.0% of the isolates were resistant to three or more of drugs. Resistance to ampicillin was the most common finding (55.0%, followed by tetracycline (40.0% and penicillin G (30.0%. The results of this study showed the wide spread of enterotoxigenic and multidrug-resistant S. aureus strains in traditional dairy products in Iran and highlighted their public health hazards.

  18. Beta-lactamase Escherichia coli and Staphylococcus aureus isolated from chickens in Nigeria

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    Godwin Onyemaechi Egwu

    2010-06-01

    Full Text Available The occurrence of beta-lactamase-producing Escherichia coli and Staphylococcus aureus in chickens was investigated. Specimens (n = 1 300 were collected from 400 chickens and were streaked on MacConkey agar plates. From each plate, presumptive growths of organisms were picked and streaked on eosin methylene blue and Baird-Parker agars, respectively. Typical colonies of E. coli and S. aureus with similar morphologies were identified by biochemical tests. Isolates were tested for beta-lactamase production and antimicrobial susceptibilities. Results indicated that 805 E. coli isolates from which 89 (11% were beta-lactamase-positive and 660 S. aureus from which 58 (8.8% were beta-lactamase-positive. Both isolates showed a high level of resistance to all twelve antibiotics screened. The increased prevalence of antibiotic resistance amongst bacterial organisms is undoubtedly correlated with the discovery and characterisation of multiple, transferrable resistance determinants, such as beta-lactamases, corresponding to their respective phenotypes. The implications of this for humans when handling and/or consuming chickens and chicken products contaminated with strains of such isolates, is a risk of transferrable multi-drug resistance and a failure of treatment. The results of our study indicated that beta-lactamase-producing E. coli and S. aureus are prevalent in chickens in Nigeria.

  19. Isolation, molecular characteristics and disinfection of methicillin-resistant Staphylococcus aureus from ICU units in Brazil.

    Science.gov (United States)

    Campos, Guilherme B; Souza, Simone G; Lob O, Tassia N; Da Silva, Danilo C C; Sousa, Daniel S; Oliveira, Pollianna S; Santos, Verena M; Amorim, Aline T; Farias, S Vio T; Cruz, Mariluze P; Yatsuda, Regiane; Marques, Lucas M

    2012-04-01

    The aim of the present study was to isolate S. aureus strains resistant to antibiotics, characterize the genotype profiles of resistance staphylococci, and evaluate the efficacy of antiseptic agents and disinfectants used in two public hospitals of Vitoria da Conquista, Bahia, Brazil. Clinical samples were obtained from ICU environments and equipment surfaces in two public hospitals in Vitoria da Conquista. Broth cultures were plated onto mannitol salt agar, and antimicrobial susceptibility testing was performed by the broth microdilution method according to CLSI. MRSA strains were submitted to PCR for detecting the mecA gene. PCR products were purified and sequenced for SCCmec type identification. Moreover, the strains were tested for efficacy of different disinfectant solutions. S. aureus were isolated from 31 and 67 sites in each hospital, respectively. Among the isolates from hospital 1, 07 (22.6%) were resistant to oxacillin while 28 (41.8%) were resistant in hospital 2. Thirty-one were positive for the mecA gene. All isolates showed SCCmec type III genotype characteristics of the Brazilian epidemic clone. In disinfectant tests, sodium hypochlorite (0.5, 1.0 and 2.0%), 2% chlorhexidine gluconate, quaternary ammonium, peracetic acid and formaldehyde were effective against the isolates tested. The strains showed higher resistance to vinegar (4% acetic acid), alcohol and glutaraldehyde. The findings of this study should assist in reducing the occurrence of nosocomial infections and therefore the morbidity, mortality and socio-economic burden caused by prolonged hospitalization.

  20. Antibiotic resistant pattern of methicillin resistant and sensitive Staphylococcus aureus isolated from patients durining 2009-2010, Ahvaz, Iran.

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    N Parhizgari

    2013-12-01

    Full Text Available Abstract Background & aim: Staphylococcus aureus is one of the most important nosocomial infecting agents resistant to commonly used antibiotics. Nowadays, methicillin-resistant S. aureus (MRSA is considered one of the main causes of nosocomial infections. The aim of this study was to identify the antibiotic resistance pattern of methicicllin- resistant and susceptible strains in Ahwaz, Iran. Methods: In the present cross - sectional study, a number of 255 clinically suspected cases of Staphylococcus aureus were collected during a 19 month period. The bacteria were investigated using standard biochemical tests such as catalase, mannitol fermentation, coagulase and Dnase. Sensitive strains were confirmed by disk diffusion method compared to commonly used antibiotics. The collected data were analyzed using descriptive statistical tests. Results: of 255 suspected cases, 180 were confirmed as S.aureus, a total of 59 strains of S. aureus (2/37 percent were resistant to methicillin. Resistance to S. aureus strains resistant to methicillin included: chloramphenicol (3.38%, rifampin (45.76%, norfloxacin (89.83%, gentamicin (89.83%, ciprofloxacin, (91.52%, azithromycin, (88.13%, cotrimoxazole (86.44% and all isolates strains were sensitive to vancomycin and nitrofurantoin. A total of 10 different patterns of antibiotic resistance in methicillin-resistant Staphylococcus aureus strains were identified. Conclusion: Expression of new resistance factor in nosocomial infection is one of the major challenges in treating these infections. This study showed a high prevalence of resistance against some class of antibiotics in MRSA isolated from Imam Khomeini and Golestan hospital of Ahwaz, Iran. Key words: Nosocomial infection, Methicillin Resistant Staphylococcus aureus (MRSA, Antibiotic Resistant Pattern

  1. Persistent Staphylococcus aureus isolates from two independent cases of bacteremia display increased bacterial fitness and novel immune evasion phenotypes.

    Science.gov (United States)

    Richards, R L; Haigh, R D; Pascoe, B; Sheppard, S K; Price, F; Jenkins, D; Rajakumar, K; Morrissey, J A

    2015-08-01

    Staphylococcus aureus bacteremia cases are complicated by bacterial persistence and treatment failure despite the confirmed in vitro susceptibility of the infecting strain to administered antibiotics. A high incidence of methicillin-resistant S. aureus (MRSA) bacteremia cases are classified as persistent and are associated with poorer patient outcomes. It is still unclear how S. aureus evades the host immune system and resists antibiotic treatment for the prolonged duration of a persistent infection. In this study, the genetic changes and associated phenotypic traits specific to S. aureus persistent bacteremia were identified by comparing temporally dispersed isolates from persistent infections (persistent isolates) originating from two independent persistent S. aureus bacteremia cases with the initial infection isolates and with three resolved S. aureus bacteremia isolates from the same genetic background. Several novel traits were associated specifically with both independent sets of persistent S. aureus isolates compared to both the initial isolates and the isolates from resolved infections (resolved isolates). These traits included (i) increased growth under nutrient-poor conditions; (ii) increased tolerance of iron toxicity; (iii) higher expression of cell surface proteins involved in immune evasion and stress responses; and (iv) attenuated virulence in a Galleria mellonella larva infection model that was not associated with small-colony variation or metabolic dormancy such as had been seen previously. Whole-genome sequence analysis identified different single nucleotide mutations within the mprF genes of all the isolates with the adaptive persistence traits from both independent cases. Overall, our data indicate a novel role for MprF function during development of S. aureus persistence by increasing bacterial fitness and immune evasion.

  2. Persistent Staphylococcus aureus Isolates from Two Independent Cases of Bacteremia Display Increased Bacterial Fitness and Novel Immune Evasion Phenotypes

    Science.gov (United States)

    Richards, R. L.; Haigh, R. D.; Pascoe, B.; Sheppard, S. K.; Price, F.; Jenkins, D.; Rajakumar, K.

    2015-01-01

    Staphylococcus aureus bacteremia cases are complicated by bacterial persistence and treatment failure despite the confirmed in vitro susceptibility of the infecting strain to administered antibiotics. A high incidence of methicillin-resistant S. aureus (MRSA) bacteremia cases are classified as persistent and are associated with poorer patient outcomes. It is still unclear how S. aureus evades the host immune system and resists antibiotic treatment for the prolonged duration of a persistent infection. In this study, the genetic changes and associated phenotypic traits specific to S. aureus persistent bacteremia were identified by comparing temporally dispersed isolates from persistent infections (persistent isolates) originating from two independent persistent S. aureus bacteremia cases with the initial infection isolates and with three resolved S. aureus bacteremia isolates from the same genetic background. Several novel traits were associated specifically with both independent sets of persistent S. aureus isolates compared to both the initial isolates and the isolates from resolved infections (resolved isolates). These traits included (i) increased growth under nutrient-poor conditions; (ii) increased tolerance of iron toxicity; (iii) higher expression of cell surface proteins involved in immune evasion and stress responses; and (iv) attenuated virulence in a Galleria mellonella larva infection model that was not associated with small-colony variation or metabolic dormancy such as had been seen previously. Whole-genome sequence analysis identified different single nucleotide mutations within the mprF genes of all the isolates with the adaptive persistence traits from both independent cases. Overall, our data indicate a novel role for MprF function during development of S. aureus persistence by increasing bacterial fitness and immune evasion. PMID:26056388

  3. Changing patterns among the subgroups of strains of Staphylococcus aureus of phage group II in Danish hospitals from 1961-91

    DEFF Research Database (Denmark)

    Eriksen, N H; Hartzen, S H; Bangsborg, Jette Marie

    1994-01-01

    During the period 1961-91 a total of 567,635 strains of Staphylococcus aureus from hospitalized patients in Denmark have been characterized according to their antibiotic resistance, site of isolation and phage type. Strains of phage group II (typed by the phages 3A, 3C, 55 and 71) have been...... analysed further. The occurrence of group II strains was relatively constant (approximately 16%) from 1961 until 1983. Since then the frequency of group II strains increased; in 1991 they accounted for 22.7% of all S. aureus strains isolated. Strains of group II can, on the basis of their phage types......, be divided in four subgroups: 3A, 71, 71+ and the 'rest of group II'. Furthermore, within these groups strains may differ from one another in respect to their sensitivity to phages. The increased isolation of group II strains during recent years was because of an increase in strains of subgroups 71...

  4. NaOCl effect on biofilm produced by Staphylococcus aureus isolated from the milking environment and mastitis infected cows

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    Poliana de Castro Melo

    2014-02-01

    Full Text Available Biofilms constitute a physical barrier, protecting the encased bacteria from detergents and sanitizers. The objective of this work was to analyze the effectiveness of sodium hypochlorite (NaOCl against strains of Staphylococcus aureus isolated from raw milk of cows with subclinical mastitis and Staphylococcus aureus isolated from the milking environment (blowers and milk conducting tubes. The results revealed that, in the presence of NaOCl (150ppm, the number of adhered cells of the twelve S. aureus strains was significantly reduced. When the same strains were evaluated in biofilm condition, different results were obtained. It was found that, after a contact period of five minutes with NaOCl (150ppm, four strains (two strains from milk , one from the blowers and one from a conductive rubber were still able to grow. Although with the increasing contact time between the bacteria and the NaOCl (150ppm, no growth was detected for any of the strains. Concerning the efficiency of NaOCl on total biofilm biomass formation by each S. aureus strain, a decrease was observed when these strains were in contact with 150 ppm NaOCl for a total period of 10 minutes. This study highlights the importance of a correct sanitation protocol of all the milk processing units which can indeed significantly reduce the presence of microorganisms, leading to a decrease of cow´s mastitis and milk contamination.

  5. Evaluation of the in vitro activity of ceftobiprole against clinical isolates of Staphylococcus aureus

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    Carola Mauri

    2016-12-01

    Full Text Available Background and aims: Ceftobiprole is a new cephalosporin characterized by a potent activity against Gram-positive and Gram-negative bacterial pathogens. It is noting that ceftobiprole has a strong affinity for penicillin binding proteins including PBP 2A, which mediates resistance to beta-lactams in methicillin (oxacillin-resistant coagulase- negative staphylococci and Staphylococcus aureus (MRSA. The aim of the current study was to examine the antimicrobial activity of ceftobiprole against clinical isolates of S. aureus recently collected at our institution. Materials and methods: One hundred and forty blood isolates of S. aureus were evaluated, including methicillin-susceptible (MSSA, n=70 and MRSA (n=70 strains. Twenty additional MRSA isolates obtained from different sites (including skin and soft tissues, blood, and lower respiratory tract and characterized by borderline susceptibility to vancomycin were also studied to assess the ability of ceftobiprole to overcome this worrisome trait. MIC values of ceftobiprole were determined by Etest strips and results were interpreted according to EUCAST guidelines. Results and conclusions: Study isolates were consistently susceptible to ceftobiprole, with MIC values ranging from 0.125 mg/L to 2 mg/L. Overall, MIC50 and MIC90 were 0.25 mg/L and 0.5 mg/L, respectively. Ceftobiprole showed in vitro activity against all S. aureus isolates, with small differences among groups selected on the basis of resistance to methicillin and/or reduced susceptibility to vancomycin. Thus, ceftobiprole appears a valid choice for treating infections caused by S. aureus, even when susceptibility results are not yet available. Additionally, ceftobiprole may be a valid option in the case of reduced susceptibility to vancomycin.

  6. Partial Sequencing of 16S rRNA Gene of Selected Staphylococcus aureus Isolates and its Antibiotic Resistance

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    Harsi Dewantari Kusumaningrum

    2016-08-01

    Full Text Available The choice of primer used in 16S rRNA sequencing for identification of Staphylococcus species found in food is important. This study aimed to characterize Staphylococcus aureus isolates by partial sequencing based on 16S rRNA gene employing primers 16sF, 63F or 1387R. The isolates were isolated from milk, egg dishes and chicken dishes and selected based on the presence of sea gene that responsible for formation of enterotoxin-A. Antibiotic susceptibility of the isolates towards six antibiotics was also tested. The use of 16sF resulted generally in higher identity percentage and query coverage compared to the sequencing by 63F or 1387R. BLAST results of all isolates, sequenced by 16sF, showed 99% homology to complete genome of four S. aureus strains, with different characteristics on enterotoxin production and antibiotic resistance. Considering that all isolates were carrying sea gene, indicated by the occurence of 120 bp amplicon after PCR amplification using primer SEA1/SEA2,  the isolates were most in agreeing to S. aureus subsp. aureus ST288. This study indicated that 4 out of 8 selected isolates were resistant towards streptomycin. The 16S rRNA gene sequencing using 16sF is useful for identification of S. aureus. However, additional analysis such as PCR employing specific gene target, should give a valuable supplementary information, when specific characteristic is expected.

  7. A report on infection dynamics of inducible clindamycin resistance of Staphylococcus aureus isolated from a teaching hospital in India

    Institute of Scientific and Technical Information of China (English)

    Debasmita Dubey; Shakti Rath; Mahesh C Sahu; Subhrajita Rout; Nagen K Debata; Rabindra N Padhy

    2013-01-01

    Objective:To investigate the infection of hospital-and community-acquired“erythromycin-induced clindamycin resistant”strains or D-test positives of clinical isolates of Staphylococcus aureus (S. aureus) (with and without methicillin resistance) in a hospital. Methods: Strains of S. aureus isolated from clinical specimens were subjected to D-test and antibiotic profiling. Results: Of the total 278 isolates, 140 (50.35%) were D-test positives and the rest were D-test negatives. Further, of 140 (100%) positives, 87 (62.14%) and 53 (37.85%) strains were from males and females, respectively. Of 140 (100%) positives, 117 (83.57%) were methicillin resistant S. aureus and 23 (16.42%) were methicillin sensitive S. aureus;of 140 strains, 103 (73.57%) strains from persons with and 37 (26.42%) were without related infections;of 140 strains, 91 (65%) and 49 (35%) were from hospital-and community-acquired samples, respectively. In 140 strains, 118 (84.28%) with comorbidities and 22 (15.71%) without comorbidities cases were recorded;similarly, persons with prior antibiotic uses contributed 108 (77.14%) and without 32 (22.85%) positive strains. These binary data of surveillance were analyzed by a univariate analysis. It was evident that the prior antibiotic uses and comorbidities due to other ailments were the determinative factors in D-test positivity, corroborated by low P values, P=0.001 1 and 0.002 4, respectively. All isolates (278) were resistant to 17 antibiotics of nine groups, in varying degrees;the minimum of 28%resistance for vancomycin and the maximum of 97%resistance for gentamicin were recorded. Further, of 278 strains, only 42 (15.1%) strains were resistant constitutively to both antibiotics, erythromycin resistant and clindamycin resistant, while 45 (16.2%) strains were constitutively sensitive to both antibiotics (erythromycin sensitive and clindamycin sensitive). Further, of the rest 191 (68.7%) strains were with erythromycin resistant and clindamycin

  8. Antibacterial Activity of Protocatechuic Acid Ethyl Ester on Staphylococcus aureus Clinical Strains Alone and in Combination with Antistaphylococcal Drugs

    Directory of Open Access Journals (Sweden)

    Maria Miklasińska

    2015-07-01

    Full Text Available The aim of the presented study was to examine in vitro the antibacterial activity of protocatechuic acid ethyl ester (ethyl 3,4-dihydroxybenzoate, EDHB against Staphylococcus aureus clinical isolates alone and in the combination with four selected antibiotics. The EDHB antimicrobial activity was tested against twenty S. aureus strains isolated from the clinical samples, and three reference strains. The phenotypes and genotypes of resistance to methicillin for the tested strains were defined as well as the phenotypic resistance to macrolides, lincosamides and streptogramin B (MLSB. EDHB displayed diverse activity against examined S. aureus strains with the minimal inhibitory concentration (MIC within the range from 64 to 1024 µg/mL. Addition of ¼ MIC of EDHB into the Mueller-Hinton Agar (MHA resulted in augmented antibacterial effect in the presence of clindamycin. In the case of cefoxitin no synergistic effect with EDHB was noted. For erythromycin and vancomycin the decrease of mean MICs in the presence of EDHB was observed but did not reach statistical significance. The results of the present study showed that in vitro EDHB possesses antibacterial activity against S. aureus clinical strains and triggers a synergistic antimicrobial effect with clindamycin and to the lesser extent with erythromycin and vancomycin.

  9. Catalase-negative Staphylococcus aureus isolated from a diabetic foot ulcer

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    MR Zali

    2010-12-01

    Full Text Available We report a catalase-negative Staphylococcus aureus isolated from a 56-year-old male diabetic patient with foot ulcer who attended our surgery ward. Species identification was confirmed by Gram staining, standard biochemical tests and PCR amplification of the nuc and fem genes. Antibiotic susceptibility showed that the strain was sensitive to imepenem, chloramphenicol, amoxicillin, vancomycin and resistant to oxacillin, penicillin, ceftriaxone, erythromycin, clindamycin, and amikacin. Clinicians and microbiologists must be encouraged to identify and report these atypical strains and the infections associated with them in order to establish their role in pathogenesis.

  10. 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. PMID:27603123

  11. Staphylococcus aureus Clinical Isolates: Antibiotic Susceptibility, Molecular Characteristics, and Ability to Form Biofilm

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    N. Indrawattana

    2013-01-01

    Full Text Available Periodic monitoring of Staphylococcus aureus characteristics in a locality is imperative as their drug-resistant variants cause treatment problem. In this study, antibiograms, prevalence of toxin genes (sea-see, seg-ser, seu, tsst-1, eta, etb, and etd, PFGE types, accessory gene regulator (agr groups, and ability to form biofilm of 92 S. aureus Thailand clinical isolates were investigated. They were classified into 10 drug groups: groups 1–7 (56 isolates were methicillin resistant (MRSA and 8–10 (36 isolates were methicillin sensitive (MSSA. One isolate did not have any toxin gene, 4 isolates carried one toxin gene (seq, and 87 isolates had two or more toxin genes. No isolate had see, etb, or tsst-1; six isolates had eta or etd. Combined seg-sei-sem-sen-seo of the highly prevalent egc locus was 26.1%. The seb, sec, sel, seu, and eta associated significantly with MSSA; sek was more in MRSA. The sek-seq association was 52.17% while combined sed-sej was not found. Twenty-three PFGE types were revealed, no association of toxin genes with PFGE types. All four agr groups were present; agr group 1 was predominant (58.70% but agr group 2 strains carried more toxin genes and were more frequent toxin producers. Biofilm formation was found in 72.83% of the isolates but there was no association with antibiograms. This study provides insight information on molecular and phenotypic markers of Thailand S. aureus clinical isolates which should be useful for future active surveillance that aimed to control a spread of existing antimicrobial resistant bacteria and early recognition of a newly emerged variant.

  12. Characterization of Staphylococcus aureus Isolated from Clinical Specimens by Matrix Assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    WANG Ye Ru; CHEN Qian; CUI Sheng Hui; LI Feng Qin

    2013-01-01

    Objective To develop a matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) approach to identify Staphylococcus aureus (S. aureus) and differentiate methicillin-resistant S. aureus (MRSA) from methicillin-sensitive S. aureus (MSSA). Methods A total of 100 S. aureus strains isolated from clinical specimens and farm workers were collected and analyzed by MALDI-TOF-MS. And data obtained were interpreted with biotyper software. Results Ninety-two strains were identified by MALDI-TOF-MS as S. aureus at a level of secure genus and probable species, and 4 strains were identified at probable genus after their cultivation, spectral collection and data preprocessing. One strain was identified as S. aureus with lower score. It was revealed that identification of S. aureus by MALDI-TOF-MS was highly correlated with typing by biochemical and serological methods with an accuracy as high as 97%. The biotyper cluster analysis showed that 100 isolates were divided into 2 types at the distance level of 400. Higher peak intensity in the mass of both 3784 Da and 5700 Da was observed in MRSA, whereas that was absent from MSSA. Conclusion MALDI-TOF-MS is considered as a simple, rapid and highly reproducible technique with high-throughput and accuracy for the identification of S. aureus and it can reliably differentiate MRSA from MSSA.

  13. Staphylococcus aureus and Staphylococcus epidermidis Virulence Strains as Causative Agents of Persistent Infections in Breast Implants.

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    Daniela Chessa

    Full Text Available Staphylococcus epidermidis and Staphylococcus aureus are currently considered two of the most important pathogens in nosocomial infections associated with catheters and other medical implants and are also the main contaminants of medical instruments. However because these species of Staphylococcus are part of the normal bacterial flora of human skin and mucosal surfaces, it is difficult to discern when a microbial isolate is the cause of infection or is detected on samples as a consequence of contamination. Rapid identification of invasive strains of Staphylococcus infections is crucial for correctly diagnosing and treating infections. The aim of the present study was to identify specific genes to distinguish between invasive and contaminating S. epidermidis and S. aureus strains isolated on medical devices; the majority of our samples were collected from breast prostheses. As a first step, we compared the adhesion ability of these samples with their efficacy in forming biofilms; second, we explored whether it is possible to determine if isolated pathogens were more virulent compared with international controls. In addition, this work may provide additional information on these pathogens, which are traditionally considered harmful bacteria in humans, and may increase our knowledge of virulence factors for these types of infections.

  14. Expression of gamma-hemolysin regulated by sae in Staphylococcus aureus strain Smith 5R.

    Science.gov (United States)

    Yamazaki, Kazuko; Kato, Fuminori; Kamio, Yoshiyuki; Kaneko, Jun

    2006-06-01

    Staphylococcus aureus strain Smith 5R produces a two-component pore-forming toxin and forms a rough-surfaced colony with hemolytic haloes on human red blood cell plates (R[+]). Serial subcultures of the strain in broth caused the appearance of gamma-hemolysin negative variants with a smooth colony shape (S[-]), and the S[-] valiant became predominant in culture. The R[+] strain, in which agrA is naturally disrupted by an insertion of IS1181, produced high levels of gamma-hemolysin. In the S[-] variant, expression of both hlg and lukS-F mRNAs was strongly reduced. Nucleotide sequencing of the sae locus revealed that all isolated S[-] variants had spontaneous mutations in the sae locus. Recovery of gamma-hemolysin productivity in S[-] by transformation of the wild-type sae allele strongly suggested that the expression of gamma-hemolysin is positively regulated by sae in an agr-independent manner.

  15. Macrolide-lincosamide-resistant phenotypes and genotypes of Staphylococcus aureus isolated from bovine clinical mastitis.

    Science.gov (United States)

    Wang, Yang; Wu, Cong-Ming; Lu, Li-Ming; Ren, Gao-Wa Na; Cao, Xing-Yuan; Shen, Jian-Zhong

    2008-07-27

    The present study aimed to determine the prevalence and mechanisms of macrolide-lincosamide (ML) resistance in 72 Staphylococcus aureus isolates from cows with clinical mastitis. Minimum inhibitory concentrations (MIC) of ML antibiotics were determined by the broth microdilution technique, inducible ML resistance phenotype by the D test, and ML resistance genes by PCR assay. The isolates showed a high level of resistance to erythromycin (93.1%), azithromycin (93.1%), spiramycin (41.7%), tylosin (40.3%), tilmicosin (27.8%), and clindamycin (36.1%). Macrolide-lincosamide MIC(90) values were > or = 128 mg/L. Inducible ML resistance (iML) phenotype was detected in 52.8% (38/72) of isolates. In erythromycin-resistant (ER-R) strains, methylase genes ermB and ermC, efflux gene msrA/msrB, and inactivating enzyme genes lnuA and mphC were present alone or in various combinations, with ermB and ermC genes predominating. This is the first report of ML resistance genes ermB, mrsA/mrsB and mphC in S. aureus isolated from bovine mastitis. The occurrence of high levels of resistance to ML antibiotics among the S. aureus isolates, and the high rate of iML phenotype, indicate that appropriate alternative antibiotics should be prescribed for treating bovine mastitis caused by S. aureus. Furthermore, significant differences in the conformations of lactone rings of 16- and 14-membered macrolides could explain why some isolates with a constitutive ML resistance (cML) phenotype were sensitive to 16-membered macrolides alone. The different interaction of the 16-membered macrolides with the 50S ribosomal subunit is also presumably the reason why the susceptibility results of tilmcosin differed from those of tylosin and spiramycin.

  16. The prevalence of methicillin-resistant Staph. aureus strains producing enterotoxin A and B

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    Safiyeh Abbasi

    2016-02-01

    Full Text Available Background: Staphylococcus aureus is a gram positive coccus which is able to cause different kinds of infection in certain condition. The function of this bacteria is to provide the conditions for the invasion of it to the host with the secretion of different sorts of toxins such as Staphylococcus aureus enterotoxin, including important virulence factors that super antigens are all factors digestive inconvenience. Staphylococcus aureus enterotoxin-secreting toxins such conditions provides invasion of host genes. There are different types of SE, but type A enterotoxin (SEA and type B enterotoxin (SEB are the most important types. Therefore, in this study, the prevalence of Staphylococcus aureus toxin-producing enterotoxin genes (SEB, SEA in clinical strains isolated from patients in teaching hospitals of Shahrekord city, Iran, were studied. Methods: This cross-sectional and descriptive study, which was conducted from May 2014 to December 2014. A hundred and ten isolates of Staphylococcus aureus from patients collected over a period of 8 months and were first identified using standard biochemical methods and laboratory. Using standard methods and laboratory tests were identified and compared with the antibiotic oxacillin minimum inhibitory concentration were determined by broth micro dilution, and then they were assessed by polymerase chain reaction (PCR technique. Results: The results indicated that, 110 samples of dairy products infected by Staphylococcus aureus were detected. Two cases (1.8% of these infected samples were carrying both enterotoxin A and enterotoxin B genes. The frequencies of enterotoxin A genes were twenty-six cases (23/6% and The frequencies of enterotoxin B genes were two cases (1/8%, respectively. Conclusion: The detection of enterotoxin A and enterotoxin B genes, shows the most important role they have in bringing about superinfection. The detection of enterotoxin A and B genes, shows the most important role they have in

  17. Impact of food-related environmental factors on the adherence and biofilm formation of natural Staphylococcus aureus isolates.

    Science.gov (United States)

    Vázquez-Sánchez, Daniel; Habimana, Olivier; Holck, Askild

    2013-02-01

    Staphylococcus aureus is a pathogenic bacterium capable of developing biofilms on food-processing surfaces, a pathway leading to cross contamination of foods. The purpose of this study was to investigate the influence of environmental stress factors found during seafood production on the adhesion and biofilm-forming properties of S. aureus. Adhesion and biofilm assays were performed on 26 S. aureus isolated from seafood and two S. aureus reference strains (ATCC 6538 and ATCC 43300). Cell surface properties were evaluated by affinity measurements to solvents in a partitioning test, while adhesion and biofilm assays were performed in polystyrene microplates under different stress conditions of temperature, osmolarity, and nutrient content. The expression of genes implicated in the regulation of biofilm formation (icaA, rbf and σ( B )) was analyzed by reverse transcription and quantitative real time PCR. In general, S. aureus isolates showed moderate hydrophobic properties and a marked Lewis-base character. Initial adhesion to polystyrene was positively correlated with the ionic strength of the growth medium. Most of the strains had a higher biofilm production at 37 °C than at 25 °C, promoted by the addition of glucose, whereas NaCl and MgCl(2) had a lower impact markedly affected by incubation temperatures. Principal Component Analysis revealed a considerable variability in adhesion and biofilm-forming properties between S. aureus isolates. Transcriptional analysis also indicated variations in gene expression between three characteristic isolates under different environmental conditions. These results suggested that the prevalence of S. aureus strains on food-processing surfaces is above all conditioned by the ability to adapt to the environmental stress conditions present during food production. These findings are relevant for food safety and may be of importance when choosing the safest environmental conditions and material during processing, packaging, and

  18. Evolution of a fatal septic arthritis caused by a Panton-Valentine leukocidin (PVL)-producing Staphylococcus aureus strain.

    Science.gov (United States)

    Rafai, Mostafa; Abouelalaa, Khalil; Skhsoukh, Yassine; Balkhi, Hicham; Belyamani, Lahcen; Dimou, M'barek

    2013-10-01

    We report the observation of a septic arthritis of the knee complicated within first 36 hours by multiorgan failure including acute respiratory distress syndrome (ARDS), heart failure, acute renal failure and disseminated intravascular coagulation (DIC). A diagnosis of staphylococcal arthritis was suspected confirmed by direct examination, and culture showed a Staphylococcus aureus sensitive to methicillin. The sample sent to the National Reference Centre for Staphylococci (Lyon, France) for genetic analysis confirmed the isolate positive for the PVL gene expression. The fulminating evolution of a septic S. aureus arthritis in an otherwise healthy man should probably evoke the possibility of LPV strain. Anti-PLV antibiotics with anti-staphylococcal activity, such as clindamycin and linezolid should be started without waiting for typing of the S. aureus strain.

  19. In vitro activity of Inula helenium against clinical Staphylococcus aureus strains including MRSA.

    LENUS (Irish Health Repository)

    O'Shea, S

    2009-01-01

    The present study aims to investigate the bactericidal activity (specifically antistaphylococcal) of Inula helenium. The antimicrobial activity of the extract is tested against 200 clinically significant Irish Staphylococcus aureus isolates consisting of methicillin-resistant (MRSA) and -sensitive (MSSA) S. aureus using a drop test method and a microbroth dilution method. The antibacterial effect is evaluated by measuring the area of the inhibition zone against the isolates. Results proved I. helenium to be 100% effective against the 200 staphylococci tested, with 93% of isolates falling within the ++ and +++ groups. The minimum bactericidal concentration of I. helenium was examined on a subset of isolates and values ranged from 0.9 mg\\/mL to 9.0 mg\\/mL. The extract was equally effective against antibiotic-resistant and -sensitive strains. This plant therefore possesses compounds with potent antistaphylococcal properties, which in the future could be used to complement infection control policies and prevent staphylococcal infection and carriage. This research supports other studies wherein herbal plants exhibiting medicinal properties are being examined to overcome the problems of antibiotic resistance and to offer alternatives in the treatment and control of infectious diseases.

  20. Novel nonsense mutation in the katA gene of a catalase-negative Staphylococcus aureus strain.

    Science.gov (United States)

    Lagos, Jaime; Alarcón, Pedro; Benadof, Dona; Ulloa, Soledad; Fasce, Rodrigo; Tognarelli, Javier; Aguayo, Carolina; Araya, Pamela; Parra, Bárbara; Olivares, Berta; Hormazábal, Juan Carlos; Fernández, Jorge

    2016-01-01

    We report the first description of a rare catalase-negative strain of Staphylococcus aureus in Chile. This new variant was isolated from blood and synovial tissue samples of a pediatric patient. Sequencing analysis revealed that this catalase-negative strain is related to ST10 strain, which has earlier been described in relation to S. aureus carriers. Interestingly, sequence analysis of the catalase gene katA revealed presence of a novel nonsense mutation that causes premature translational truncation of the C-terminus of the enzyme leading to a loss of 222 amino acids. Our study suggests that loss of catalase activity in this rare catalase-negative Chilean strain is due to this novel nonsense mutation in the katA gene, which truncates the enzyme to just 283 amino acids.

  1. Effect of peracetic acid on biofilms formed by Staphylococcus aureus and Listeria monocytogenes isolated from dairy plants.

    Science.gov (United States)

    Lee, S H I; Cappato, L P; Corassin, C H; Cruz, A G; Oliveira, C A F

    2016-03-01

    This research investigated the removal of adherent cells of 4 strains of Staphylococcus aureus and 1 Listeria monocytogenes strain (previously isolated from dairy plants) from polystyrene microtiter plates using peracetic acid (PAA, 0.5%) for 15, 30, 60, and 120 s, and the inactivation of biofilms formed by those strains on stainless steel coupons using the same treatment times. In the microtiter plates, PAA removed all S. aureus at 15 s compared with control (no PAA treatment). However, L. monocytogenes biofilm was not affected by any PAA treatment. On the stainless steel surface, epifluorescence microscopy using LIVE/DEAD staining (BacLight, Molecular Probes/Thermo Fisher Scientific, Eugene, OR) showed that all strains were damaged within 15 s, with almost 100% of cells inactivated after 30 s. Results of this trial indicate that, although PAA was able to inactivate both S. aureus and L. monocytogenes monospecies biofilms on stainless steel, it was only able to remove adherent cells of S. aureus from polystyrene microplates. The correct use of PAA is critical for eliminating biofilms formed by S. aureus strains found in dairy plants, although further studies are necessary to determine the optimal PAA treatment for removing biofilms of L. monocytogenes.

  2. Phenotypic Variation Is Almost Entirely Independent of the Host-Pathogen Relationship in Clinical Isolates of S. aureus.

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    Adrian D Land

    Full Text Available A key feature of Staphylococcus aureus biology is its ability to switch from an apparently benign colonizer of ~30% of the population to a cutaneous pathogen, to a deadly invasive pathogen. Little is known about the mechanisms driving this transition or the propensity of different S. aureus strains to engender different types of host-pathogen interactions. At the same time, significant weight has been given to the role of specific in vitro phenotypes in S. aureus virulence. Biofilm formation, hemolysis and pigment formation have all been associated with virulence in mice.To determine if there is a correlation between in vitro phenotype and the three types of host-pathogen relationships commonly exhibited by S. aureus in the context of its natural human host, we assayed 300 clinical isolates for phenotypes implicated in virulence including hemolysis, sensitivity to autolysis, and biofilm formation. For comparative purposes, we also assayed phenotype in 9 domesticated S. aureus strains routinely used for analysis of virulence determinants in laboratory settings.Strikingly, the clinical strains exhibited significant phenotypic uniformity in each of the assays evaluated in this study. One exception was a small, but significant, correlation between an increased propensity for biofilm formation and isolation from skin and soft tissue infections (SSTIs. In contrast, we observed a high degree of phenotypic variation between common laboratory strains that exhibit virulence in mouse models. These data suggest the existence of significant evolutionary pressure on the S. aureus genome and highlight a role for host factors as a strong determinant of the host-pathogen relationship. In addition, the high degree of variation between laboratory strains emphasizes the need for caution when applying data obtained in one lab strain to the analysis of another.

  3. Comparative analysis of the virulence characteristics of epidemic methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from Chinese children: ST59 MRSA highly expresses core gene-encoded toxin.

    Science.gov (United States)

    Li, Shipeng; Sun, Jing; Zhang, Jianzhong; Li, Xiangmei; Tao, Xiaoxia; Wang, Lijuan; Sun, Mingjiao; Liu, Yingchao; Li, Juan; Qiao, Yanhong; Yu, Sangjie; Yao, Kaihu; Yang, Yonghong; Shen, Xuzhuang

    2014-02-01

    This study aims to investigate the prevalence of a novel cell wall-anchored protein gene, sasX, and to obtain information on the genetic basis for the pathogenic potential of the MRSA strains isolated from Chinese children. The molecular and virulence characteristics of the clinical strains were analyzed. Twenty-two sequence types (STs) were obtained, with six epidemic clones ST59, ST239, ST1, ST910, ST88, and ST338 accounting for 35.8, 22, 6.6, 6.6, 5.3, and 4.1% respectively. The expression levels of hla, psmα, and RNAIII were higher in ST59 than in other STs (p MRSA isolates. ST239-MRSA-SCCmecIII-t037 (61.5%) was the predominant sasX-positive MRSA clone. The expressions of PSMα and RNAIII were higher in sasX-positive ST239 isolates than in sasX-negative ST239 ones (p MRSA was higher than that by sasX-negative ST239 MRSA (p = 0.008). This study indicated that ST59 was the predominant clone in the MRSA isolates obtained from Chinese children and might have stronger pathogenic potential. The prevalence of the sasX gene in the MRSA isolates from children was relatively low. Furthermore, the sasX gene might be related to the expressions of PSMα and RNAIII and infection invasiveness.

  4. Development of multiplex PCR for detection of pathogenic genes in the Staphylococcus aureus strains isolated from skin and soft tissue infections%皮肤软组织及创伤感染金黄色葡萄球菌分离株的毒素基因检测

    Institute of Scientific and Technical Information of China (English)

    邓家德; 陈惠玲; 叶惠芬; 凌艳英; 李焕庭; 杨银梅; 周小棉

    2012-01-01

    Objective To examine the prevalence of the genes encoding Panton-Valentine leukocidin (PVL), exfoliative toxin (ETs) , toxic shock syndrome toxin 1 (TSST-1) , and some antibiotic resistant genes in the Staphylococcus aureus strains isolated from skin and soft tissue infections. Methods A total of 90 strains of S. aureus were isolated from skin and soft tissue infections. Antibiotic susceptibility testing was done by Kirby-Bauer method. The results were interpreted according to CLSI 2009 breakpoints. Multiplex PCR was designed to detect S. aureus specific 16S rRNA gene, mecA, and PVL gene. The genes encoding, TSST-1 and EtsA and EtsB were amplified by PCR. Results The prevalence of mecA gene was 52. 2% (47/90). Positive mecA defines the strain as methicillin-resistant (MRSA). EtsB gene was positive in 1 of the MRSA strains. TSST-1 gene was also identified in only 1 MRSA strain. PVL gene was positive in 7 of the S. aureus strains, 3 of which carried mecA gene. Conclusions S. aureus may release various toxins. PVL-positive strains usually cause severe infection. Attention must be paid to the toxin-producing MRSA strains.%目的 了解皮肤软组织及创伤感染的金葡菌携带的杀白细胞素(Panton-Valentine Leukocidin,PVL)基因、表皮剥脱性毒素(ETs)基因、中毒性休克综合征毒素-1(TSST-1)的tst基因的特点.方法 对连续收集的皮肤软组织感染中分离的90株金葡菌,采用多重PCR同时检测金葡菌特异性16SrRNA基因、mecA基因、PVL基因,采用PCR法检测TSST-1及EtsA、B基因.结果 金葡菌mecA基因阳性47株(占金葡菌52.2%)为耐甲氧西林金葡菌(MRSA).有1株MRSA的EtsB基因阳性,1株MRSA的TSST-1阳性,有7株金葡菌携带PVL基因,其中3株为mecA基因阳性株(MRSA).结论 金葡菌可分泌多种毒素,携带PVL毒素的金葡菌常可以引起严重的侵袭性感染,尤其对产毒的MRSA感染引起足够的重视,是防控的重点.

  5. Activity of the thiopeptide antibiotic nosiheptide against contemporary strains of methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Haste, Nina M; Thienphrapa, Wdee; Tran, Dan N; Loesgen, Sandra; Sun, Peng; Nam, Sang-Jip; Jensen, Paul R; Fenical, William; Sakoulas, George; Nizet, Victor; Hensler, Mary E

    2012-12-01

    The rapid rise in antimicrobial resistance in bacteria has generated an increased demand for the development of novel therapies to treat contemporary infections, especially those caused by methicillin-resistant Staphylococcus aureus (MRSA). However, antimicrobial development has been largely abandoned by the pharmaceutical industry. We recently isolated the previously described thiopeptide antibiotic nosiheptide from a marine actinomycete strain and evaluated its activity against contemporary clinically relevant bacterial pathogens. Nosiheptide exhibited extremely potent activity against all contemporary MRSA strains tested including multiple drug-resistant clinical isolates, with MIC values 0.25 mg l(-1). Nosiheptide was also highly active against Enterococcus spp. and the contemporary hypervirulent BI/NAP1/027 strain of Clostridium difficile but was inactive against most Gram-negative strains tested. Time-kill analysis revealed nosiheptide to be rapidly bactericidal against MRSA in a concentration- and time-dependent manner, with a nearly 2-log kill noted at 6 h at 10 × MIC. Furthermore, nosiheptide was found to be non-cytotoxic against mammalian cells at >100 × MIC, and its anti-MRSA activity was not inhibited by 20% human serum. Notably, nosiheptide exhibited a significantly prolonged post-antibiotic effect against both healthcare- and community-associated MRSA compared with vancomycin. Nosiheptide also demonstrated in vivo activity in a murine model of MRSA infection, and therefore represents a promising antibiotic for the treatment of serious infections caused by contemporary strains of MRSA.

  6. Antibacterial potential of some plants of traditional use in India against pathogenic strains ofS. aureus

    Institute of Scientific and Technical Information of China (English)

    Abdul Viqar Khan; Qamar Uddin Ahmed; Athar Ali Khan

    2015-01-01

    Objective:To evaluate antibacterial sensitivity of 43 ethnomedicinally important plants belonging to 25 different families from Western Uttar Pradesh, a northern province in India, against hospital isolated pathogenic strains ofStaphylococcus aureus (S. aureus). Methods: Methanol (MeOH) and aqueous extracts of plants were subjected to sensitivity test againstS. aureusATCC25953 and two hospital isolated virulent strains ofS. aureusSA1 and SA2 following disc diffusion assay to determine sensitivity and agar dilution method to test minimum inhibition concentration using Mueller-Hinton agar. Results: Potential antibacterial activity was recorded for MeOH extracts against test pathogens, while moderate antibacterial activity was observed in case of aqueous extracts. Out of 43 plant species, 39 species were found sensitive to tested strains. Minimum inhibition concentration values of MeOH extracts were demonstrated at low concentration ranging from 15.5 mg/mL up to 45.5 mg/mL compared to aqueous extracts which were observed ranging from 30.0 mg/mL up to 95.0 mg/mL. Conclusions:The present findings strongly support traditional uses of these plants in the treatment of infectious maladies and further urge of phytochemical and pharmacological research to develop safer and cheaper drugs for the benefit of ailing humanity.

  7. Molecular epidemiology of clinical and carrier strains of methicillin resistant Staphylococcus aureus (MRSA in the hospital settings of north India

    Directory of Open Access Journals (Sweden)

    Dar Mohammad J

    2006-09-01

    Full Text Available Abstract Background The study was conducted between 2000 and 2003 on 750 human subjects, yielding 850 strains of staphylococci from clinical specimens (575, nasal cultures of hospitalized patients (100 and eye & nasal sources of hospital workers (50 & 125 respectively in order to determine their epidemiology, acquisition and dissemination of resistance genes. Methods Organisms from clinical samples were isolated, cultured and identified as per the standard routine procedures. Susceptibility was measured by the agar diffusion method, as recommended by the Nat ional Committee for Clinical Laboratory Standards (NCCLS. The modified method of Birnboin and Takahashi was used for isolation of plasmids from staphylococci. Pulsed-field gel electrophoresis (PFGE typing of clinical and carrier Methicillin resistant Staphylococcus aureus (MRSA strains isolated during our study was performed as described previously. Results It was shown that 35.1% of Staphylococcus aureus and 22.5% of coagulase-negative staphylococcal isolates were resistant to methicillin. Highest percentage of MRSA (35.5% was found in pus specimens (n = 151. The multiple drug resistance of all MRSA (n = 180 and Methicillin resistant Coagulase-negative Staphylococcus aureus (MRCNS (n = 76 isolates was detected. In case of both methicillin-resistant as well as methicillin-sensitive Saphylococcal isolates zero resistance was found to vancomycin where as highest resistance was found to penicillin G followed by ampicillin. It was shown that the major reservoir of methicillin resistant staphylococci in hospitals are colonized/infected inpatients and colonized hospital workers, with carriers at risk for developing endogenous infection or transmitting infection to health care workers and patients. The results were confirmed by molecular typing using PFGE by SmaI-digestion. It was shown that the resistant markers G and T got transferred from clinical S. aureus (JS-105 to carrier S. aureus (JN-49

  8. Clonal distribution and possible microevolution of methicillin-resistant Staphylococcus aureus strains in a teaching hospital in Malaysia

    Institute of Scientific and Technical Information of China (English)

    Xin Ee Tan; Hui-min Neoh; Salasawati Hussin; Noraziah Mohamad Zin

    2013-01-01

    Objective: To genotypically characterize methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from medical and surgical wards in Universiti Kebangsaan Malaysia Medical Centre (UKMMC) in 2009. Methods: MRSA strains were collected and molecularly typed by pulsed-field gel electrophoresis (PFGE). Results:PFGE typing on 180 MRSA isolated in UKMMC identified 5 pulsotypes (A-E) and 6 singletons, where pulsotypes B and C were suspected to be divergent clones originating from a single ancestor. This study also showed that most MRSA strains were isolated from swab (119 isolates), followed by blood (22 isolates), tracheal aspirate (11 isolates) and sputum (10 isolates). On the other hand, urine and bone isolates were less, which were 4 and 1 isolates, respectively. The distribution of different pulsotypes of MRSA among wards suggested that MRSA was communicated in surgical and medical wards in UKMMC, with pulsotype B MRSA as the dominant strain. Besides, it was found that most deceased patients were infected by pulsotype B MRSA, however, no particular pulsotype could be associated with patient age, underlying disease, or ward of admittance. Conclusions: Five pulsotypes of MRSA and 6 singletons were identified, with pulsotype B MRSA as the endemic strains circulating in these wards, which is useful in establishment of preventive measures against MRSA transmission.

  9. ANTIMICROBIAL RESISTANCE PATTERN OF STAPHYLOCOCCUS AUREUS ISOLATES FROM DAKSHINA KANNADA

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    Rao Venkatakrishna

    2011-03-01

    Full Text Available Methicillin resistant Staphylococcus aureus (MRSA is an important cause of infections in hospitals and pose a great challenge to the treating clinicians; even emergence of vancomycin resistance has been reported. Therefore the knowledge of prevalence of MRSA and their antimicrobial profile becomes necessary. This study is aimed to determine prevalence of MRSA and their antimicrobial sensitivity pattern in Dakshina Kannada.Clinical specimens and carrier samples were cultured as per standard methods. The isolates were identified by using catalase test, coagulase tube test, mannitol fermentation and DNAase test. Antimicrobial susceptibility test was done for the isolates as per Kirby-Bauer disc diffusion method; the isolates were also tested for methicillin resistance using oxacillin and cefoxitin discs.A total of 250 isolates were tested (200 clinical isolates and 50 from carriers and 67 MRSA isolates were obtained (52 clinical samples and 15 from carriers. The degree of resistance to penicillin, ampicillin, ciprofloxacin, clindamycin and erythromycin were 100%, 100%, 53-56%, 14-16 % and 45-48% respectively. Resistance to vancomycin was not found. As the degree of resistance of MRSA towards antibiotics varies from region to region, in vitro susceptibility testing of every isolate of MRSA in clinical laboratories is inevitable.

  10. Characterization of Staphylococcus aureus isolates from pediatric patients with cystic fibrosis.

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    Liu, Ying; Zhang, Jiang; Zhong, Dengke; Ji, Lu; Yang, Junshu; Phillips, James; Ji, Yinduo

    2016-10-01

    Staphylococcus aureus is one of the major respiratory pathogens associated with cystic fibrosis (CF) patients. In this study, we collected sputum and isolated fifty S. aureus isolates from CF patients with the median age of 9.5 years old. Then we determined the profiles of these isolates by antibiotic susceptibility testing, examining their cytotoxicity and ability to internalize into an epithelial cell line (A549), as well as multiple loci sequencing typing. Predominant CF S. aureus isolates were resistant to penicillin; however, these isolates were sensitive to various antibiotics, such as vancomycin and minocycline. Different CF S. aureus isolates showed distinct cytotoxic activities, and 90 % of CF S. aureus isolates possessed the enterotoxin genes, sea and hlg. Moreover, we found that multiple different CF S. aureus isolates appeared to have the distinct capacity of invading A549 cells. ST5 (14 %), ST30 (14 %), and ST8 (10 %) were prevalent ST types in these isolates. Further analysis revealed that ST5 and ST30 isolates were less toxic than ST8 and ST15 isolates, and that the ST5, ST15, ST59, and ST87 types of CF S. aureus were less capable of invading A549 cells. Our results suggest that the ST typing method may be useful in predicting cytotoxicity and the invading capacity of S. aureus isolates from patients with CF.

  11. Molecular characterization of Staphylococcus aureus isolates causing skin and soft tissue infections in patients from Malakand, Pakistan.

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    Madzgalla, S; Syed, M A; Khan, M A; Rehman, S S; Müller, E; Reissig, A; Ehricht, R; Monecke, S

    2016-09-01

    Comparatively few studies have been published describing Staphylococcus aureus/MRSA epidemiology in Central Asia including Pakistan. Here, we report the genotyping of Staphylococcus aureus strains (that include both methicillin-susceptible and methicillin-resistant Staphylococcus aureus) from community- and hospital-acquired skin and soft-tissue infections in a tertiary care hospital in the Malakand district of the Khyber Pakhtunkhwa Province of Pakistan. Forty-five isolates of Staphylococcus aureus were characterized by microarray hybridization. Twenty isolates (44 %) were MRSA, whereas 22 (49 %) were PVL-positive. Fourteen isolates (31 %) harboured both mecA and PVL genes. The dominant clones were CC121-MSSA (n = 15, 33 %) and the PVL-positive "Bengal Bay Clone" (ST772-MRSA-V; n = 13, 29 %). The PVL-positive CC8-MRSA-IV strain "USA300" was found once. The pandemic ST239-MRSA-III strain was absent, although it has previously been observed in Pakistan. These observations require a re-assessment of schemes for initial antibiotic therapy to cover MRSA and they emphasise the need for a rapid and non-molecular test for PVL.

  12. The cefazolin inoculum effect in methicillin-susceptible Staphylococcus aureus blood isolates: their association with dysfunctional accessory gene regulator (agr).

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    Wi, Yu Mi; Park, Young Kyoung; Moon, Chisook; Ryu, Seong Yeol; Lee, Hyuck; Ki, Hyun Kyun; Cheong, Hae Suk; Son, Jun Seong; Lee, Jin Seo; Kwon, Ki Tae; Kim, June Myong; Ha, Young Eun; Kang, Cheol In; Ko, Kwan Soo; Chung, Doo Ryeon; Peck, Kyong Ran; Song, Jae-Hoon

    2015-11-01

    We evaluated the clinical significance of the cefazolin inoculum effect (CIE) in methicillin-susceptible Staphylococcus aureus (MSSA) isolates. In total, 146 isolates were recovered from patients with MSSA bacteremia at 9 hospitals in Korea. The CIE was observed in 16 MSSA isolates, and while type A was the only detected β-lactamase in MSSA isolates exhibiting the CIE, no strains expressing type B, C, or D β-lactamases exhibited this effect. The CIE was only observed in agr group III and I isolates and was significantly more common in isolates with agr dysfunction than in those with functional agr (P<0.001). Even among isolates producing type A β-lactamase, the CIE was also prevalent in isolates with dysfunctional agr than in isolates with functional agr (P=0.025). This study demonstrates an association between the CIE of MSSA isolates and agr dysfunction, in addition to those between the CIE and type A β-lactamase.

  13. Isolation and characterization of Staphylococcus aureus from raw cow milk in Bangladesh

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    Mueena Jahan

    2015-03-01

    Full Text Available The study was intended for identification and characterization of Staphylococcus aureus isolated from raw cow milk. A total of 47 milk samples were collected from Sheshmore, Shutiakhali and Bangladesh Agricultural University Dairy Farm, Mymensingh. Using bacteriological, biochemical and PCR-based identification schemes, 12 (25.53% isolates were confirmed as S. aureus. All the isolates showed β-hemolysis on 5% sheep blood agar. S. aureus specific nuc gene (target size 279-bp was amplified in the cases of all isolates. The isolates were found as resistant to Penicillin (100%, Erythromycin (75% and Amoxicillin (100%. On the other hand, the isolates were sensitive to Ciprofloxacin (83.33%, Oxacillin (100%, Cloxacillin (100% and Neomycin (100%. The isolated S. aureus showed increased resistance to broad spectrum antibiotic (e.g., Ciprofloxacin. As many people have a tendency to drink raw milk and raw milk products, there is high risk of S. aureus infection in human.

  14. The molecular epidemiology of the highly virulent ST93 Australian community Staphylococcus aureus strain.

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    Geoffrey W Coombs

    Full Text Available In Australia the PVL-positive ST93-IV [2B], colloquially known as "Queensland CA-MRSA" has become the dominant CA-MRSA clone. First described in the early 2000s, ST93-IV [2B] is associated with skin and severe invasive infections including necrotizing pneumonia. A singleton by multilocus sequence typing (MLST eBURST analysis ST93 is distinct from other S. aureus clones. To determine if the increased prevalence of ST93-IV [2B] is due to the widespread transmission of a single strain of ST93-IV [2B] the genetic relatedness of 58 S. aureus ST93 isolated throughout Australia over an extended period were studied in detail using a variety of molecular methods including pulsed-field gel electrophoresis, spa typing, MLST, microarray DNA, SCCmec typing and dru typing. Identification of the phage harbouring the lukS-PV/lukF-PV Panton Valentine leucocidin genes, detection of allelic variations in lukS-PV/lukF-PV, and quantification of LukF-PV expression was also performed. Although ST93-IV [2B] is known to have an apparent enhanced clinical virulence, the isolates harboured few known virulence determinants. All PVL-positive isolates carried the PVL-encoding phage ΦSa2USA and the lukS-PV/lukF-PV genes had the same R variant SNP profile. The isolates produced similar expression levels of LukF-PV. Although multiple rearrangements of the spa sequence have occurred, the core genome in ST93 is very stable. The emergence of ST93-MRSA is due to independent acquisitions of different dru-defined type IV and type V SCCmec elements in several spa-defined ST93-MSSA backgrounds. Rearrangement of the spa sequence in ST93-MRSA has subsequently occurred in some of these strains. Although multiple ST93-MRSA strains were characterised, little genetic diversity was identified for most isolates, with PVL-positive ST93-IVa [2B]-t202-dt10 predominant across Australia. Whether ST93-IVa [2B] t202-dt10 arose from one PVL-positive ST93-MSSA-t202, or by independent acquisitions of

  15. 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.

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    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.

  16. Impact of Colonization Pressure and Strain Type on Methicillin-Resistant Staphylococcus aureus Transmission in Children

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    Popoola, Victor O.; Carroll, Karen C.; Ross, Tracy; Reich, Nicholas G.; Perl, Trish M; Milstone, Aaron M.

    2013-01-01

    We studied the transmissibility of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) and healthcare-associated methicillin-resistant S. aureus (HA-MRSA) strains and the association of MRSA colonization pressure and MRSA transmission in critically ill children. Importantly, we found that in hospitalized children MRSA colonization pressure above 10% increases the risk of MRSA transmission 3-fold, and CA-MRSA and HA-MRSA strains have similar transmission dynamics.

  17. The isolation of Staphylococcus aureus tea tree oil-reduced susceptibility mutants.

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    Cuaron, Jesus A; Dulal, Santosh; Cooke, Peter H; Torres, Nathanial J; Gustafson, John E

    2014-08-01

    Tea tree oil (TTO)-reduced susceptibility (TTORS) mutants of two Staphylococcus aureus laboratory strains were isolated utilizing TTO gradient plates. Attempts to isolate TTORS mutants employing agar plates containing single TTO concentrations failed. All TTORS mutants demonstrated a small colony variant (SCV) phenotype and produced cells with a smaller diameter, as determined by scanning electron microscopy. The addition of SCV auxotrophic supplements to media did not lead to an increase in TTORS mutant colony size. Revertants were also isolated from the TTORS mutants following growth in drug-free media, and all revertant strains demonstrated phenotypes similar to their respective parent strains. Transmission electron microscopy revealed that an SH1000 TTORS mutant demonstrated a thinner cell wall and novel septal invaginations compared with parent strain SH1000. In addition, comparative genomic sequencing did not reveal any mutations in an SH1000 TTORS mutant previously linked to well-characterized SCV genotypes. This study demonstrates that TTO can select for a unique SCV phenotype.

  18. Bovine mastitis Staphylococcus aureus: antibiotic susceptibility profile, resistance genes and molecular typing of methicillin-resistant and methicillin-sensitive strains in China.

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    Wang, Dengfeng; Wang, Zhicai; Yan, Zuoting; Wu, Jianyong; Ali, Tariq; Li, Jianjun; Lv, Yanli; Han, Bo

    2015-04-01

    The emergence of methicillin-resistant Staphylococcus aureus (MRSA) infection in dairy animals is of great concern for livestock and public health. The aim of present study was to detect new trends of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) towards antibiotic susceptibility, resistance genes and molecular typing by methods of disc diffusion, multiplex PCR assay and multilocus sequence typing (MLST). A total of 219 S. aureus strains were isolated from bovine mastitis cases from six provinces of China, including 34 MRSA strains. The results revealed that more than 70% isolated strains showed resistance to various antibiotics, and multiple-drugs resistance to more than five categories of antibiotics was found more common. The ermC was the most prevalent resistance gene, followed by other genes; however, ermA was the least frequently detected gene. Twenty-eight mecA-negative MRSA and six mecA-positive MRSA strains were detected, and in which three strains were ST97-MRSA-IV, others were ST965-MRSA-IV, ST6-MRSA-IV and ST9-MRSA-SCCmec-NT. The mecA-negative MRSA strains were found resistant to most of the antibiotics, and harbored aac(6')/aph(2''), aph(3')-III and tetM genes higher than MSSA strains. The resistance to most of the antibiotics was significantly higher in MRSA than in MSSA strains. The MLST profiles showed that these strains mainly belonged to CC5, CC398, CC121 and CC50 lineage, especially within ST97 and ST398, while some novel sequence types (ST2154, ST2165 and ST2166) were identified and deposited in the MLST database. This indicates that the resistance of S. aureus is becoming more complicated by changes in multi-drug resistance mechanism and appearance of mecA-negative MRSA isolates, and importantly, MRSA-IV strains in different MLST types are emerging.

  19. ORIGINAL ARTICLE: Status of Methicillin Resistant Staphylococcus aureus Infections and Evaluation of PVL Producing Strains in Belgaum, South India

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    Harbhajan Kaur

    2012-07-01

    Full Text Available Background: Panton Valentine Leukocidin (PVL toxin, responsible for increased virulence and more severe infections can be found in both Methicillin-sensitive and Methicillin-resistant strains of Staphylococcus aureus (MSSA and MRSA. Aims & Objectives: To generate baseline data on the extent of MRSA infections and to estimate the frequency of PVL-positive S.aureus in Belgaum, South India. Material & Methods: 70 clinical isolates of S.aureus were obtained from various laboratories in Belgaum city. Theseisolates were identified, phenotypically characterized as MRSA/MSSA by disc diffusion method using oxacillin discs (1 µg and genetically by multiplex PCR for mecA and fem B genes. PCR was subsequently carried out on all isolates to detect LukS-PV and LukF-PV genes, the markers for potential producers of PVL toxin. Results: 27 out of 70 isolates (38.6% were confirmed as MRSA by PCR formecA. The prevalence of PVL gene was 85.1% and 48.8% in MRSA and MSSA respectively. The overall prevalence of PVL positive S.aureuswas 62.85%. Conclusion: Our study showed high percentage of PVL positive MRSA and MSSA, higher than the most reports worldwide. In the backdrop of bacterial strains gaining multiple drug resistance, our study warrants further epidemiological studies in hospitals and community levels in the region.

  20. Molecular epidemiology and antimicrobial resistance of methicillin-resistant Staphylococcus aureus bloodstream isolates in Taiwan, 2010.

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    Chih-Jung Chen

    Full Text Available The information of molecular characteristics and antimicrobial susceptibility pattern of methicillin-resistant Staphylococcus aureus (MRSA is essential for control and treatment of diseases caused by this medically important pathogen. A total of 577 clinical MRSA bloodstream isolates from six major hospitals in Taiwan were determined for molecular types, carriage of Panton-Valentine leukocidin (PVL and sasX genes and susceptibilities to 9 non-beta-lactam antimicrobial agents. A total of 17 genotypes were identified in 577 strains by pulsotyping. Five major pulsotypes, which included type A (26.2%, belonging to sequence type (ST 239, carrying type III staphylococcal chromosomal cassette mec (SCCmec, type F (18.9%, ST5-SCCmecII, type C (18.5%, ST59-SCCmecIV, type B (12.0%, ST239-SCCmecIII and type D (10.9%, ST59-SCCmecVT/IV, prevailed in each of the six sampled hospitals. PVL and sasX genes were respectively carried by ST59-type D strains and ST239 strains with high frequencies (93.7% and 99.1%, respectively but rarely detected in strains of other genotypes. Isolates of different genotypes and from different hospitals exhibited distinct antibiograms. Multi-resistance to ≥3 non-beta-lactams was more common in ST239 isolates (100% than in ST5 isolates (97.2%, P = 0.0347 and ST59 isolates (8.2%, P<0.0001. Multivariate analysis further indicated that the genotype, but not the hospital, was an independent factor associated with muti-resistance of the MRSA strains. In conclusion, five common MRSA clones with distinct antibiograms prevailed in the major hospitals in Taiwan in 2010. The antimicrobial susceptibility pattern of invasive MRSA was mainly determined by the clonal distribution.

  1. Antibiotic sensitivity and phage typing of Staphylococcus aureus isolated from non-hospitalized patients with angular cheilitis.

    Science.gov (United States)

    MacFarlane, T W; McGill, J C; Samaranayake, L P

    1984-12-01

    Strains of Staphylococcus aureus were isolated from 360 patients with angular cheilitis. Of these 24 per cent were sensitive to penicillin G, 74 per cent to tetracycline, 93 per cent to fusidic acid and 96 per cent to erythromycin. Twenty per cent belonged to bacteriophage Group I, 9 per cent to Group II, 13 per cent to Group III, 39 percent miscellaneous and 19 per cent were untypable. A number of phage typing patterns which have been reported for strains associated with specific forms of staphylococcal disease were present in the 360 isolates. In investigations involving cross infection of Staph. aureus, both patients and staff should be examined for evidence of infection at the angles of the mouth.

  2. Clonal distribution of bone sialoprotein-binding protein gene among Staphylococcus aureus isolates associated with bloodstream infections.

    Science.gov (United States)

    Wiśniewska, Katarzyna; Piórkowska, Anna; Kasprzyk, Joanna; Bronk, Marek; Świeć, Krystyna

    2014-11-01

    Staphylococcus aureus is a leading cause of bloodstream infections (BSI) and diseases that may be caused by hematogenous spread. The staphylococcal adhesin, for which the association with the infections emerging as a complication of septicemia has been well documented, is a bone sialoprotein-binding protein (Bbp). The aim of the study was to assess the prevalence of a bbp gene in S. aureus bloodstream isolates associated with BSI and to investigate to what degree the distribution of this gene is linked to the clonality of the population. Spa typing, used in order to explore the genetic population structure of the isolates, yielded 29 types. Six spa clusters and seven singletons were identified. The most frequent was spa clonal complex CC021 associated with MLST CC30 (38%). The bbp gene was found in 47% of isolates. Almost all isolates (95%) clustered in spa clonal complex CC021 were positive for this gene. All isolates carrying the bbp gene were sensitive to methicillin, and if clustered in the spa CC021, belonged to agr group III. Our study shows that Bbp is not strictly associated with BSI. However, one may conclude that for clonally related S. aureus strains most commonly causing BSI, the risk of Bbp-mediated complications of septicemia is expected to be higher than for other strains.

  3. Toward an understanding of the evolution of Staphylococcus aureus strain USA300 during colonization in community households.

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    Uhlemann, Anne-Catrin; Kennedy, Adam D; Martens, Craig; Porcella, Stephen F; Deleo, Frank R; Lowy, Franklin D

    2012-01-01

    Staphylococcus aureus is a frequent cause of serious infections and also a human commensal. The emergence of community-associated methicillin-resistant S. aureus led to a dramatic increase in skin and soft tissue infections worldwide. This epidemic has been driven by a limited number of clones, such as USA300 in the United States. To better understand the extent of USA300 evolution and diversification within communities, we performed comparative whole-genome sequencing of three clinical and five colonizing USA300 isolates collected longitudinally from three unrelated households over a 15-month period. Phylogenetic analysis that incorporated additional geographically diverse USA300 isolates indicated that all but one likely arose from a common recent ancestor. Although limited genetic adaptation occurred over the study period, the greatest genetic heterogeneity occurred between isolates from different households and within one heavily colonized household. This diversity allowed for a more accurate tracking of interpersonal USA300 transmission. Sequencing of persisting USA300 isolates revealed mutations in genes involved in major aspects of S. aureus function: adhesion, cell wall biosynthesis, virulence, and carbohydrate metabolism. Genetic variations also included accumulation of multiple polymorphisms within select genes of two multigene operons, suggestive of small genome rearrangements rather than de novo single point mutations. Such rearrangements have been underappreciated in S. aureus and may represent novel means of strain variation. Subtle genetic changes may contribute to USA300 fitness and persistence. Elucidation of small genome rearrangements reveals a potentially new and intriguing mechanism of directed S. aureus genome diversification in environmental niches and during pathogen-host interactions.

  4. Antibiotic sensitivity pattern of Staphylococcus aureus from clinical isolates in a tertiary health institution in Kano, Northwestern Nigeria

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    Nwankwo Emmanuel Onwubiko

    2011-01-01

    Full Text Available BACKGROUND: The importance of Staphylococcus aureus as a persistent nosocomial and community acquired pathogen has become a global health concern. It has a remarkable capability of evolving different mechanisms of resistance to most antimicrobial agents. The aim of the present study is to establish the incidence of S. aureus in clinical specimens and its antibiotic sensitivity pattern to various antibiotics in this locality. METHODS: One hundred and fifty consecutive isolates of S. aureus obtained from various clinical specimens between January and December 2009 sent to the Medical Microbiology Laboratory Department of Aminu Kano Teaching Hospital (AKTH were confirmed by standard bacteriological procedures. Antibiotic sensitivity pattern was carried out by disc diffusion method. RESULTS: The age group with the highest number of isolates was (0-10yrs while wound infection had the highest frequency of S. aureus isolates (30.7% in the study. Males (62.0% were more infected than females (38.0%. The sensitivity pattern of S. aureus to the following antibiotics; Gentamicin, Amoxycillin/clavulanate, Streptomycin, Cloxacillin, Erythromycin, Chloramphenicol, Cotrimoxazole, Tetracycline, Penicillin, Ciprofloxacin, Ofloxacin, Levofloxacin, Ceftriaxone, Amoxycillin and vancomycin were 92.4%, 63.0%, 44.2%, 35.8%, 52.4%, 61.9%, 15.5%, 31.2%, 7.1%, 78.9%, 76.6%, 100%, 71.4%, 30.7% and 100% respectively. Methicillin resistant isolates were sensitive to Levofloxacin 93.7% and Ofloxacin 68.7%. CONCLUSION: The results of the present study show that the fluoroquinolones are effective in the management of Staphylococcus aureus infections including methicillin resistant strains in this environment.

  5. Molecular characterization of Staphylococcus aureus isolates from skin and soft tissue infections samples and healthy carriers in the Central Slovenia region.

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    Svent-Kucina, Natasa; Pirs, Mateja; Kofol, Romina; Blagus, Rok; Smrke, Dragica Maja; Bilban, Marjan; Seme, Katja

    2016-04-01

    Staphylococcus aureus is among the most important human pathogens. It is associated with different infections and is a major cause of skin and soft tissue infections (SSTIs). The aim of our study was to compare S. aureus isolates associated with SSTIs with isolates obtained from healthy carriers in the Central Slovenia region in terms of antimicrobial susceptibility, genetic diversity by clonal complex (CC)/sequence type, spa type, and by toxin gene profiling. In total, 274 S. aureus isolates were collected prospectively by culturing wound samples from 461 SSTI patients and nasal samples from 451 healthy carriers. We have demonstrated high heterogeneity in terms of CCs and spa type in both groups of isolates. The main clone among SSTI strains was Panton-Valentine leukocidin gene (pvl) positive CC121, whereas the main clone among carrier strains was CC45 carrying a large range of toxin genes. The main spa type in both groups was t091. Pvl was more frequently present in SSTI strains (31.2% SSTI vs 3.6% carrier strains) and staphylococcal enterotoxin C was more frequently present in carrier strains (1.6% SSTI vs 17.0% carrier strains). We have also demonstrated that methicillin-resistant S. aureus was a rare cause (2.8%) of SSTIs in our region.

  6. Draft Genome Sequences of a Unique t324-ST541-V Methicillin-Resistant Staphylococcus aureus Strain from a Pig.

    Science.gov (United States)

    Moon, Dong Chan; Kim, Byung-Yong; Nam, Hyang-Mi; Jang, Geum-Chan; Jung, Suk-Chan; Lee, Hee-Soo; Park, Yong-Ho; Lim, Suk-Kyung

    2016-04-28

    Methicillin-resistant Staphylococcus aureus (MRSA), the major causative agent of nosocomial infection, has also been reported from non-human sources. A sequence type (ST) 541 MRSA isolate designated K12PJN53 was isolated from a healthy pig in 2012. The genome of K12PJN53 consists of 44 contiguous sequences (contigs), totalling 2,880,108 bases with 32.88% GC content. Among the annotated contigs, 14, 17, and 18 contained genes related to antimicrobial resistance, adherence, and toxin genes, respectively. The genomic distance of strain K12PJN53 was close to the ST398 strains. This is the first report of the draft genome sequence of a novel livestock-associated MRSA ST541 strain.

  7. Characterization of nasal and blood culture isolates of methicillin-resistant Staphylococcus aureus from patients in United States Hospitals.

    Science.gov (United States)

    Tenover, Fred C; Tickler, Isabella A; Goering, Richard V; Kreiswirth, Barry N; Mediavilla, José R; Persing, David H

    2012-03-01

    A total of 299 nares and 194 blood isolates of methicillin-resistant Staphylococcus aureus (MRSA), each recovered from a unique patient, were collected from 23 U.S. hospitals from May 2009 to March 2010. All isolates underwent spa and staphylococcal cassette chromosome mec element (SCCmec) typing and antimicrobial susceptibility testing; a subset of 84 isolates was typed by pulsed-field gel electrophoresis (PFGE) using SmaI. Seventy-six spa types were observed among the isolates. Overall, for nasal isolates, spa type t002-SCCmec type II (USA100) was the most common strain type (37% of isolates), while among blood isolates, spa type t008-SCCmec type IV (USA300) was the most common (39%). However, the proportion of all USA100 and USA300 isolates varied by United States census region. Nasal isolates were more resistant to tobramycin and clindamycin than blood isolates (55.9% and 48.8% of isolates versus 36.6% and 39.7%, respectively; for both, P United States, were observed along with several unusual PFGE types, including CMRSA9, EMRSA15, and the PFGE profile associated with sequence type 239 (ST239) isolates. Typing data from this convenience sample suggest that in U.S. hospitalized patients, USA100 isolates of multiple spa types, while still common in the nares, have been replaced by USA300 isolates as the predominant MRSA strain type in positive blood cultures.

  8. Comparative genome-scale modelling of Staphylococcus aureus strains identifies strain-specific metabolic capabilities linked to pathogenicity

    Science.gov (United States)

    Bosi, Emanuele; Monk, Jonathan M.; Aziz, Ramy K.; Fondi, Marco; Nizet, Victor; Palsson, Bernhard Ø.

    2016-01-01

    Staphylococcus aureus is a preeminent bacterial pathogen capable of colonizing diverse ecological niches within its human host. We describe here the pangenome of S. aureus based on analysis of genome sequences from 64 strains of S. aureus spanning a range of ecological niches, host types, and antibiotic resistance profiles. Based on this set, S. aureus is expected to have an open pangenome composed of 7,411 genes and a core genome composed of 1,441 genes. Metabolism was highly conserved in this core genome; however, differences were identified in amino acid and nucleotide biosynthesis pathways between the strains. Genome-scale models (GEMs) of metabolism were constructed for the 64 strains of S. aureus. These GEMs enabled a systems approach to characterizing the core metabolic and panmetabolic capabilities of the S. aureus species. All models were predicted to be auxotrophic for the vitamins niacin (vitamin B3) and thiamin (vitamin B1), whereas strain-specific auxotrophies were predicted for riboflavin (vitamin B2), guanosine, leucine, methionine, and cysteine, among others. GEMs were used to systematically analyze growth capabilities in more than 300 different growth-supporting environments. The results identified metabolic capabilities linked to pathogenic traits and virulence acquisitions. Such traits can be used to differentiate strains responsible for mild vs. severe infections and preference for hosts (e.g., animals vs. humans). Genome-scale analysis of multiple strains of a species can thus be used to identify metabolic determinants of virulence and increase our understanding of why certain strains of this deadly pathogen have spread rapidly throughout the world. PMID:27286824

  9. Comparative genome-scale modelling of Staphylococcus aureus strains identifies strain-specific metabolic capabilities linked to pathogenicity.

    Science.gov (United States)

    Bosi, Emanuele; Monk, Jonathan M; Aziz, Ramy K; Fondi, Marco; Nizet, Victor; Palsson, Bernhard Ø

    2016-06-28

    Staphylococcus aureus is a preeminent bacterial pathogen capable of colonizing diverse ecological niches within its human host. We describe here the pangenome of S. aureus based on analysis of genome sequences from 64 strains of S. aureus spanning a range of ecological niches, host types, and antibiotic resistance profiles. Based on this set, S. aureus is expected to have an open pangenome composed of 7,411 genes and a core genome composed of 1,441 genes. Metabolism was highly conserved in this core genome; however, differences were identified in amino acid and nucleotide biosynthesis pathways between the strains. Genome-scale models (GEMs) of metabolism were constructed for the 64 strains of S. aureus These GEMs enabled a systems approach to characterizing the core metabolic and panmetabolic capabilities of the S. aureus species. All models were predicted to be auxotrophic for the vitamins niacin (vitamin B3) and thiamin (vitamin B1), whereas strain-specific auxotrophies were predicted for riboflavin (vitamin B2), guanosine, leucine, methionine, and cysteine, among others. GEMs were used to systematically analyze growth capabilities in more than 300 different growth-supporting environments. The results identified metabolic capabilities linked to pathogenic traits and virulence acquisitions. Such traits can be used to differentiate strains responsible for mild vs. severe infections and preference for hosts (e.g., animals vs. humans). Genome-scale analysis of multiple strains of a species can thus be used to identify metabolic determinants of virulence and increase our understanding of why certain strains of this deadly pathogen have spread rapidly throughout the world.

  10. Isolation, purification and characterization of pyruvate kinase from Staphylococcus aureus : a potential drug target

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    K. Venkatesh

    2014-04-01

    Full Text Available Background: With emergence of multidrug-resistant strains of Staphylococcus aureus, there is an urgent need for the development of new antimicrobials which are narrow and pathogen specific. In this context, pyruvate kinase (PK an important enzyme in the glycolysis, which catalyses the formation of pyruvate which is the key intersection in the network of metabolic pathways was isolated and purified from Staphylococcus aureus ATCC12600. Methods: Purification steps included 10%-20% ammonium sulphate fractionation, diethyl aminoethyl cellulose ion exchange chromatography followed by gel filtration on Sephadex G-100. The pure PK molecular weight was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE and Km and Vmax for the PK was demonstrated. Results: The pure PK obtained from Sephadex G-100 gel filtration column exhibited Km of 0.78+0.18 µM and Vmax 76.47+0.82 µM NADH/mg/min and molecular weight of 250 kDa in solution. However, in SDS-PAGE showed single band with a molecular weight of 63 kDa confirming the homotetramer nature. In all steps of purification the Km remained constant indicating presence of only one kind of enzyme. The PK gene searched in the genomic sequences of Staphylococcus aureus also confirmed the same. Interpretation and conclusions: In Staphylococcus aureus presence of only one kind of PK unlike in other Gram positive bacteria exhibiting distinct differences in enzyme kinetics. This enzyme also showed the functionality of PK is found to be different from its human host. Therefore, PK probably is regarded as an ideal drug target in the development of new potent antimicrobials.

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

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    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.

  12. Methicillin-resistant Staphylococcus aureus (MRSA) isolated from animals and veterinary personnel in Ireland.

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    O'Mahony, R; Abbott, Y; Leonard, F C; Markey, B K; Quinn, P J; Pollock, P J; Fanning, S; Rossney, A S

    2005-08-30

    Reports of methicillin-resistant Staphylococcus aureus (MRSA) in animals have become more frequent in recent years. This paper documents the recovery of MRSA from animals with respiratory, urinary tract or wound infection and from animals subjected to surgical procedures following treatment in one veterinary hospital and 16 private veterinary clinics in different geographical locations throughout Ireland. MRSA was recovered from 25 animals comprising 14 dogs, eight horses, one cat, one rabbit and a seal, and also from 10 attendant veterinary personnel. Clinical susceptibility testing suggested that the 35 isolates fell into two different groups. One group of isolates (Group 1) was resistant to one or more of the following classes of antimicrobials: macrolides, lincosamines, tetracyclines and/or fluoroquinolones. The second group (Group 2) was resistant to macrolides, aminoglycosides, tetracyclines and trimethoprim/sulphamethoxazole and variably resistant to fluoroquinolones, lincosamines and rifampicin. One isolate in Group 2 was susceptible to trimethoprim. Epidemiological typing by antibiogram-resistogram (AR) typing, biotyping and by chromosomal DNA restriction fragment length polymorphism analysis using SmaI digestion followed by pulsed field gel electrophoresis (PFGE), confirmed these two major clusters. PFGE analysis showed that most isolates from non-equine animals were indistinguishable from each other and from the isolates from personnel caring for these animals. MRSA was isolated from eight horses which attended six different veterinary practices before referral to an equine veterinary hospital. Isolates from the eight horses and from their attendant personnel had PFGE patterns that were indistinguishable and were unlike the patterns obtained from the other isolates. Comparison of PFGE patterns of isolates from veterinary sources with patterns from MRSA recovered in human hospitals showed that the most frequently occurring pattern of MRSA from non

  13. Antibiotic-resistance Staphylococcus aureus isolated from cow’s milk in the Hawassa area, South Ethiopia

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    Daka Deresse

    2012-09-01

    Full Text Available Abstract Background Quarter milk samples from cows were examined to determine the prevalence of Staphylococcus aureus (SA and different antibiotic resistant pattern were determined in a cross-sectional study design. Objective The objective of this study was to isolate Staphylococcus aureus from samples of cow’s milk obtained from Hawassa area and to determine their antibiotic susceptibility patterns. Method A total of 160 milk (CCP1-CCP5 samples were collected and screened for the presence of S. aureus. Gram staining, oxidase, catalase, DNase, haemolysis and coagulase tests were employed for bacterial identification. Results All the samples were contaminated with S. aureus. A total of 78 S. aureus isolates were obtained during this study. The levels of contamination with S. aureus were higher in milk obtained from CCP1, CCP2, CCP3, CCP4 and CCP5 at Hawassa area farms (18.0%, 25.6%, 27.0%, 21.8% and 7.7% respectively. A large percentage of the S. aureus isolates (25.6% and 27.0% were from CCP2 and CCP3. All strains were resistant to Penicillin G (PG (10 μg, Ampicillin (AP (10 μg, Amoxicillin-Clavulanic acid (AC (30 μg, Ciprofloxacin (CIP (5 μg, Erythromycin (E (15 μg, Ceftriaxone (CRO (30 μg, Trimethoprime-Sulfamethoxazole (TMP-SMZ (25 μg Oxacillin (Ox (1 μg and Vancomycin (V (30 μg, 67.9%, 70.9%, 30.9%, 0%, 32.1%, 23.1%, 7.7%, 60.3% and 38.5% respectively. Conclusion The proportion of isolates resistant to CIP, TMP-SMZ, CRO, AC, E and V were low compared to AP, PG and Ox. S. aureus is normally resident in humans; therefore, the S. aureus present in the cow’s milk may have resulted from transmission between the two species, emphasizing the need to improve sanitary conditions in the milking environment.

  14. Activity of ceftobiprole against methicillin-resistant Staphylococcus aureus strains with reduced susceptibility to daptomycin, linezolid or vancomycin, and strains with defined SCCmec types.

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    Farrell, David J; Flamm, Robert K; Sader, Helio S; Jones, Ronald N

    2014-04-01

    Ceftobiprole is a broad-spectrum cephalosporin with activity against methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative pathogens including Pseudomonas aeruginosa. The aim of this study was to evaluate the activity of ceftobiprole against MRSA isolates with decreased susceptibility to daptomycin, linezolid or vancomycin as well as isolates from staphylococcal chromosome cassette mec (SCCmec) types I, II, III and IV. Overall, ceftobiprole demonstrated high potency against the 216 isolates tested, with MIC50 and MIC90 values (minimum inhibitory concentrations required to inhibit 50% and 90% of the isolates, respectively) of 1mg/L and 2mg/L (97.2% susceptible). The MIC90 for ceftobiprole was 2mg/L against the linezolid-non-susceptible, daptomycin-non-susceptible and vancomycin-intermediate (VISA and hVISA) subsets and was 1mg/L against the vancomycin-resistant (VRSA) strains. The MIC50/90 values for ceftobiprole were 2/4, 1/2, 2/2 and 1/1mg/L against SCCmec types I, II, III and IV, respectively. SCCmec type I strains had the highest MICs, with six strains exhibiting a ceftobiprole MIC of 4mg/L and 15 strains at 2mg/L. Ceftobiprole demonstrated potent activity against MRSA, including subsets of isolates with reduced susceptibility to daptomycin, linezolid and vancomycin. The activity of ceftobiprole against these resistant phenotypes indicates that it may have clinical utility in the treatment of infections caused by multidrug-resistant S. aureus and across strains from prevalent SCCmec types.

  15. Detection of grlA and gyrA mutations in 344 Staphylococcus aureus strains.

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    Wang, T; Tanaka, M; Sato, K

    1998-02-01

    Mutations in the grlA and gyrA genes of 344 clinical strains of Staphylococcus aureus isolated in 1994 in Japan were identified by combinations of single-strand conformation polymorphism analysis, restriction fragment length analysis, and direct sequencing to identify possible relationships to fluoroquinolone resistance. Five types of single-point mutations and four types of double mutations were observed in the grlA genes of 204 strains (59.3%). Four types of single-point mutations and four types of double mutations were found in the gyrA genes of 188 strains (54.7%). Among them, the grlA mutation of TCC-->TTC or TAC (Ser-80-->Phe or Tyr) and the gyrA mutation of TCA-->TTA (Ser-84-->Leu) were principal, being detected in 137 (39.8%) and 121 (35.9%) isolates, respectively. The grlA point mutations of CAT-->CAC (His-77 [silent]), TCA-->CCA (Ser-81-->Pro), and ATA-->ATT (Ile-100 [silent]) were novel, as was the GAC-->GGC (Asp-73-->Gly) change in gyrA. A total of 15 types of mutation combinations within both genes were related to ciprofloxacin resistance (MIC > or = 3.13 microg/ml) and were present in 193 mutants (56.1%). Strains containing mutations in both genes were highly resistant to ciprofloxacin (MIC at which 50% of the isolates are inhibited [MIC50] = 50 microg/ml). Those with the Ser80-->Phe or Tyr alteration in grlA but wild-type gyrA showed a lower level of ciprofloxacin resistance (MIC50 < or = 12.5 microg/ml). Levofloxacin was active against 68 of 193 isolates (35.2%) with mutations at codon 80 of grlA in the presence or absence of a concomitant mutation at codon 73, 84, or 88 in gyrA (MIC < or = 6.25 microg/ml). The new fluoroquinolone DU-6859a showed good activity with 186 of 193 isolates (96.4%) for which the MIC was < or = 6.25 microg/ml.

  16. Biofilms of a Bacillus subtilis hospital isolate protect Staphylococcus aureus from biocide action.

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    Arnaud Bridier

    Full Text Available The development of a biofilm constitutes a survival strategy by providing bacteria a protective environment safe from stresses such as microbicide action and can thus lead to important health-care problems. In this study, biofilm resistance of a Bacillus subtilis strain (called hereafter ND(medical recently isolated from endoscope washer-disinfectors to peracetic acid was investigated and its ability to protect the pathogen Staphylococcus aureus in mixed biofilms was evaluated. Biocide action within Bacillus subtilis biofilms was visualised in real time using a non-invasive 4D confocal imaging method. The resistance of single species and mixed biofilms to peracetic acid was quantified using standard plate counting methods and their architecture was explored using confocal imaging and electronic microscopy. The results showed that the ND(medical strain demonstrates the ability to make very large amount of biofilm together with hyper-resistance to the concentration of PAA used in many formulations (3500 ppm. Evidences strongly suggest that the enhanced resistance of the ND(medical strain was related to the specific three-dimensional structure of the biofilm and the large amount of the extracellular matrix produced which can hinder the penetration of peracetic acid. When grown in mixed biofilm with Staphylococcus aureus, the ND(medical strain demonstrated the ability to protect the pathogen from PAA action, thus enabling its persistence in the environment. This work points out the ability of bacteria to adapt to an extremely hostile environment, and the necessity of considering multi-organism ecosystems instead of single species model to decipher the mechanisms of biofilm resistance to antimicrobials agents.

  17. Phenotypes and genotypes of old and contemporary porcine strains indicate a temporal change in the S. aureus population structure in pigs.

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    Carmen Espinosa-Gongora

    Full Text Available Staphylococcus aureus sequence type ST398 has recently gained attention due to the spread of methicillin-resistant strains among people exposed to livestock. The aim of this study was to explore temporal changes in the population structure of S. aureus in pigs over the last 40 years with particular reference to the occurrence of ST398.We analysed a unique collection of 91 porcine strains isolated in six countries between 1973 and 2009 using a biotyping scheme described in the 1970's in combination with spa typing and multi-locus sequence typing (MLST. The collection comprised 32 historical isolates from 1973-1974 (n = 19 and from 1991-2003 (n = 13, and 59 contemporary isolates from 2004-2009. The latter isolates represented the most common MLST types (ST1, ST9, ST97 and ST433 and spa types isolated from pigs in Europe.S. aureus sequence type ST398 was not found among old isolates from the 1970's or from 1991-2003, suggesting that this lineage was absent or present at low frequencies in pigs in the past. This hypothesis is supported by the observed association of ST398 with the ovine ecovar, which was not described in pigs by studies carried out in the 1970's. In addition, various phenotypic and genotypic differences were observed between old and contemporary isolates. Some biotypes commonly reported in pigs in the 1970's were either absent (human ecovar or rare (biotype A among contemporary isolates. Nine clonal lineages found among old porcine isolates are occasionally reported in pigs today (ST8, ST30, ST97, ST387, ST1092, ST2468 or have never been described in this animal host (ST12, ST133, ST1343. These results indicate that the population structure of porcine S. aureus has changed over the last 40 years and confirm the current theory that S. aureus ST398 does not originate from pigs.

  18. High frequency of multidrug-resistant Staphylococcus aureus with SCCmec type III and Spa types t037 and t631 isolated from burn patients in southwest of Iran.

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    Parhizgari, Najmeh; Khoramrooz, Seyed Sajjad; Malek Hosseini, Seyed Ali Asghar; Marashifard, Masoud; Yazdanpanah, Mahboobeh; Emaneini, Mohammad; Gharibpour, Farzaneh; Mirzaii, Mehdi; Darban-Sarokhalil, Davood; Moein, Masoud; Naraki, Mahmood

    2016-03-01

    Methicilin resistance Staphylococcus aureus (MRSA) infections are the major challenges in hospitals, especially in the burn units. The use of molecular typing methods is essential for tracking the spread of S. aureus infection and epidemiological investigations. The aim of this study was to find the profile of the spa types and also the prevalence of each SCCmec type of S. aureus strains in a central burn hospital in southwest of Iran. A total of 81 non-duplicate S. aureus were isolated from burn patients between April 2011 and February 2012. The susceptibility of the isolates against 13 different antibiotics was tested by disk agar diffusion (DAD) method. MRSA strains were identified by amplification of mecA gene. Multiplex-polymerase chain reaction (PCR) technique was used to determine the SCCmec types of MRSA strains and all the S. aureus isolates were typed by spa typing method. Detection of mecA gene showed that 70 (86.4%) of the isolates were MRSA. The highest rate of resistance was observed for penicillin (97.5%) and erythromycin (77.8%). None of the isolates were resistant to vancomycin. Sixty-seven of the 70 MRSA isolates harbored only SCCmec type III and three untypeable isolates. Five different spa types were detected. The most common spa types were t037 (42.5%) and t631 (34.5%) and were only found in MRSA isolates. Only SCCmec type III was found in burn patients which emphasizes the HA-MRSA origin of these strains. Only five different spa types identified in this study are in accordance with one SCCmec type which indicates that a limited number of bacterial colons are circulated in the burn unit in this hospital.

  19. whole-genome sequence of livestock-associated st398 methicillin-resistant staphylococcus aureus Isolated from Humans in Canada.

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    Golding, George R; Bryden, Louis; Levett, Paul N; McDonald, Ryan R; Wong, Alice; Graham, Morag R; Tyler, Shaun; Van Domselaar, Gary; Mabon, Philip; Kent, Heather; Butaye, Patrick; Smith, Tara C; Kadlec, Kristina; Schwarz, Stefan; Weese, Scott J; Mulvey, Michael R

    2012-12-01

    Despite reports of high colonization rates of ST398 livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) among pigs and pig farmers, the incidence of LA-MRSA infection in the general population in Canada appears to be rare in comparison to that in some European countries. In this study, the complete genome sequence of a Canadian representative LA-MRSA isolate (08BA02176) from a human postoperative surgical site infection was acquired and compared to the sequenced genome of an LA-MRSA isolate (S0385) from Europe to identify genetic traits that may explain differences in the success of these particular strains in some locales.

  20. Association between the enterotoxin production and presence of Coa, Nuc genes among Staphylococcus aureus isolated from various sources, in Shiraz.

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    Moghassem Hamidi, R; Hosseinzadeh, S; Shekarforoush, S S; Poormontaseri, M; Derakhshandeh, A

    2015-01-01

    The present study was aimed to identify the frequency of coagulase (Coa) and thermonuclease (Nuc) genes and Staphylococcal enterotoxin A (Sea) production among Staphylococcus aureus isolated from various sources in Shiraz. Moreover, the correlation between the Sea gene and coagulase and thermonuclease enzymes is also considered. A total of 100 S. aureus were isolated from various sources including 40 humans, 30 animals and 30 food samples by the routine biochemical tests. The frequency of Coa, Nuc and Sea genes was evaluated by PCR assay. Correlation among those genes was finally evaluated by statistical analysis. The PCR results showed that the prevalence of Coa, Nuc and Sea genes was 91%, 100% and 14%, respectively. The evaluation of the enterotoxin production indicated that 78.6% of the Sea gene was expressed. The presence of enterotoxin A was not necessarily correlated to the production of toxin. As a final conclusion to detect the enterotoxigenic strains, both genotypic and phenotypic methods are highly recommended.

  1. Characterization of Haemolysin of Staphylococcus aureus Isolated from Food of Animal Origin

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    Dwi Ariyanti

    2015-11-01

    Full Text Available Staphylococcus aureus is an important pathogen bacteria causing food poisoning and various infection in animals and humans. Haemolysin is one of the virulence factors of Staphylococcus aureus. The aims of the research were to characterize haemolysins of Staphylococcus aureus isolated from various food of animal origin, phenotypic- and genotypically. In the present study, eleven Staphylococcus aureus isolated from various food of animal origins from traditional markets and supermarkets in Yogyakarta, Sidoarjo, Jakarta, and Bandung were characterized for haemolysin, pheno- and genotypically. Characterization of haemolysin phenotypically based on haemolysis pattern of Staphylococcus aureus on sheep blood agar plate. Genes encoding hemolysin were amplified with specific primers by using polymerase chain reaction (PCR technique. The results of the studies showed that Staphylococcus aureus on sheep blood agar plates revealed an alpha haemolysis pattern (18,18%, beta haemolysis (27,27% and gamma haemolysis (54,55%. Based on amplification of the gene encoding haemolysin of Staphylococcus aureus with specific primers showed hla genes (81,81%, and hla combined with hlb genes (18,18%. The amplification of gene hla and hlb had a single amplicon with a size of approximately 534 bp and 833 bp, respectively. The haemolysin characteristics of Staphylococcus aureus from various food of animal origin could be used as important information to control staphylococcal food poisoning.Keywords : Staphylococcus aureus, haemolysin, PCR, food of animal origins

  2. Frequency of Antiseptic Resistance Among Staphylococcus aureus and Coagulase-Negative Staphylococci Isolated From a University Hospital in Central Iran

    Science.gov (United States)

    Taheri, Nona; Ardebili, Abdollah; Amouzandeh-Nobaveh, Alireza; Ghaznavi-Rad, Ehsanollah

    2016-01-01

    Objectives Reduced biocide susceptibility in Staphylococci is associated with various antiseptic resistance genes encoding efflux systems. Our aim was to determine the susceptibility to three disinfectant agents, including benzalkonium chloride (BAC), benzethonium chloride (BZT), and chlorhexidine digluconate (CHDG) among clinical isolates of Staphylococcus aureus and coagulase-negative Staphylococci (CoNS). Methods The minimum inhibitory concentration (MIC) of 60 methicillin-resistant S. aureus (MRSA), 54 methicillin-sensitive S. aureus (MSSA) and 51 CoNS isolates from a single hospital to three biocidal agents (BAC, BZT, and CHDG) was determined. Biocide resistance genes (qacA/B, smr, qacG, qacH, qacJ, and norA) were analyzed by the polymerase chain reaction assay. Results All isolates had MICs for BAC and BZT from 0.25 to 8 µg/mL, and for CHDG from 0.5 to 64 µg/mL. qacA/B was the most common biocide resistance gene among all 165 Staphylococcus isolates (76; 46%), which comprised 38 (63.3%) MRSA, 14 (25.9%) MSSA, and 24 (47%) CoNS. Eleven (6.7%) and 24 (14.5%) isolates among the 165 Staphylococci carried smr and norA genes, respectively. In contrast, other resistance genes such as qacG, qacH, and qacJ were absent in all Staphylococci studied. The qacA/B and smr genes were detected concomitantly in 3% of isolates, and 23.6% strains of the total 165 Staphylococcus isolates were negative for each studied gene. Conclusions The carriage of several biocide resistance genes, including qacA/B, smr, and norA, alone or concurrently, is associated with reduced susceptibility. Use of antiseptics may select for antibiotic-resistant strains and assist their survival in the healthcare environment. PMID:27974958

  3. Properties of an Arcanobacterium haemolyticum strain isolated from a donkey.

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    Sammra, Osama; Balbutskaya, Anna; Nagib, Samy; Alber, Jörg; Lämmler, Christoph; Abdulmawjood, Amir; Timke, Markus; Kostrzewa, Markus; Prenger-Berninghoff, Ellen

    2014-01-01

    The present study was designed to characterize phenotypically and genotypically an Arcanobacterium haemolyticum strain (A. haemolyticum P646) isolated from a purulent nasal discharge of a donkey. A. haemolyticum P646 showed, compared to sheep blood, an enhanced hemolytic reaction on rabbit blood agar, a synergistic CAMP-like reaction with Streptococcus agalactiae and Rhodococcus equi as indicator strains, a reverse CAMP reaction in the zone of Staphylococcus aureus beta-hemolysin and the typical biochemical properties of this species. The species identity could be confirmed by MALDI-TOF MS analysis, by sequencing the 16S rDNA and glyceraldehyde-3-phosphate dehydrogenase encoding gene gap and by amplification of A. haemolyticum specific parts of 16S-23S rDNA intergenic spacer region and 23S rDNA. A. haemolyticum P646 and the reference strain A. haemolyticum DSM 20595 were further characterized by amplification of the putative virulence genes encoding arcanolysin, phospholipase D, hemolysin A, CAMP factor family protein, a collagen binding protein and two neuraminidases which were present for A. haemolyticum DSM 20595. A. haemolyticum P646 showed a comparable gene spectrum but was negative for the genes encoding collagen binding protein and neuraminidase H. To our knowledge, the present study is the first phenotypic and genotypic characterization of an A. haemolyticum strain isolated from a donkey.

  4. Comparison of methods for the detection of biofilm formation by Staphylococcus aureus isolated from bovine subclinical mastitis

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    de Castro Melo, Poliana; Ferreira, Luciano Menezes; Filho, Antônio Nader; Zafalon, Luiz Francisco; Vicente, Hinig Isa Godoy; de Souza, Viviane

    2013-01-01

    Biofilm formation is considered to be a selective advantage for Staphylococcus aureus mastitis isolates by facilitating bacterial persistence in the udder. It requires attachment to mammary epithelium, proliferation and accumulation of cells in multilayers. The objective of this study was to determine the sensitivity and specificity of three techniques for the detection of S. aureus biofilm-positive strains. Two phenotypic tests, including growth on microtitre plates and Congo red agar, were compared with a PCR technique using 94 S. aureus strains obtained from cows with subclinical mastitis from two farms in the state of São Paulo. These strains were characterised by in vitro slime production on Congo red agar, biofilm formation on microtitre plates and the presence of the icaA and icaD genes. The results revealed that 85% of the isolates tested produced slime on the Congo red agar, 98.9% of the isolates produced biofilms in vitro by adhering to sterile 96-well “U” bottom polystyrene tissue culture plates, and 95.7% of the isolates carried the icaA and icaD genes. The results of the phenotypic tests for biofilm formation were compared with those of the molecular analysis, and the sensitivity and specificity of the Congo red agar test were 88.9% and 100%, respectively, while those of the microtitre plate test were 100% and 25%, respectively. When the phenotypic methods for the detection of biofilm producers, namely growth on microtitre plates and Congo red agar, were compared, the sensitivity and specificity were 86% and 100%, respectively. Therefore, growth on Congo red agar and the microtitre plate test are methods that could be used to determine whether an isolate has the potential for biofilm production. PMID:24159293

  5. Ultrastructural Study on the Antibacterial Activity of Artonin E versus Streptomycin against Staphylococcus aureus Strains.

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    Zajmi, Asdren; Mohd Hashim, Najihah; Noordin, Mohamed Ibrahim; Khalifa, Shaden A M; Ramli, Faiqah; Mohd Ali, Hapipah; El-Seedi, Hesham R

    2015-01-01

    Staphylococci are facultative anaerobes, perfectly spherical un-encapsulated cocci, with a diameter not exceeding 1 micrometer in diameter. Staphylococcus aureus are generally harmless and remain confined to the skin unless they burrow deep into the body, causing life-threatening infections in bones, joints, bloodstream, heart valves and lungs. Among the 20 medically important staphylococci species, Staphylococcus aureus is one of the emerging human pathogens. Streptomycin had its highest potency against Staphylococcus infections despite the likelihood of getting a resistant type of staphylococcus strains. Methicillin-resistant S. aureus (MRSA) is the persister type of Staphylococcus aureus and was evolved after decades of antibiotic misuse. Inadequate penetration of the antibiotic is one of the principal factors related to success/failure of the therapy. The active drug needs to reach the bacteria at concentrations necessary to kill or suppress the pathogen's growth. In turn the effectiveness of the treatment relied on the physical properties of Staphylococcus aureus. Thus understanding the cell integrity, shape and roughness is crucial to the overall influence of the therapeutic agent on S. aureus of different origins. Hence our experiments were designed to clarify ultrastructural changes of S. aureus treated with streptomycin (synthetic compound) in comparison to artonin E (natural compound). In addition to the standard in vitro microbial techniques, we used transmission electron microscopy to study the disrupted cell architecture under antibacterial regimen and we correlate this with scanning electron microscopy (SEM) to compare results of both techniques.

  6. Isolation of antibacterials from the mangrove, Avicennia marina and their activity against multi drug resistant Staphylococcus aureus

    Institute of Scientific and Technical Information of China (English)

    N.B.Dhayanithi; T. T. Ajith Kumar; R. Ganesha Murthy; K. Kathiresan

    2012-01-01

    Objective: leaf extract of A. marina was tested on the growth of clinically isolated multi-drug resistant Staphylococcus aureus and its bioactive compounds were attempted. Method: Clinical strain of Staphylococcus aureus, were isolated from sputum, pus and blood of different patients and 22 strains were screened for antibiotic susceptibility. Avicennia marina was extracted in different solvents and antibacterial assay was carried out using Kirby-Bauer’s disk diffusion method. Crude methanol extract of the mangrove was loaded on a silica gel column and eluted with chloroform and methanol (9:1 to 1:9) followed by ethyl acetate and methanol (9:1 to 1:9). Based on in vitro assay, the 12th fraction was subjected for minimum inhibitory concentration (MIC). The active fraction was analysed by using a Clarus 500 Perkin Elmer gas chromatography. Result: Based on the antibiotic susceptibility test, six strains (RMSA 6, RMSA12, RMSA16, RMSA18, RMSA19 and RMSA21) were resistance against methicillin, vancomycin and ciprofloxacin. The results indicated that the methanolic leaf extract showed the highest antibacterial activity against all the tested strains RMSA 6 (16mm), RMSA12 (15 mm), RMSA16 (13 mm), RMSA18 (10 mm), RMSA19 (17 mm) and RMSA21 (16 mm). The MIC of the partially purified extract showed potential results against all the multidrug resistant strains however, the lowest concentration was recorded against RMSA 6, RMSA19 and RMSA21 strain. In the GC-MS results, 5 bioactive compounds were identified from the partially purified extract of A.marina. Conclusion:The methanolic extract of A. marina has the more potential candidate to inhibit against multidrug resistant S. aureus.

  7. Genetic diversity of community-associated methicillin-resistant Staphylococcus aureus isolated from Tenerife Island, Spain.

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    Rivero-Pérez, Belinda; Alcoba-Flórez, Julia; Méndez-Álvarez, Sebastián

    2012-04-01

    With the recent detection of MRSA (methicillin-resistant Staphylococcus aureus) infections in patients lacking health care-related risk factors, the term community-acquired MRSA (CA-MRSA) has been become widely recognised. Many cases of CA-MRSA spreading to the community have been described worldwide. The aim of this study was to determine the features of CA-MRSA isolates from Tenerife Island. Toward this end, one hundred MRSA isolates were collected from eight different health regions, and their molecular features were investigated. This study revealed a wide variety of MRSA clones, including an emergent ST: ST1434 (CC8) and two new spa types, t7575 (ST125) and t7678 (ST22). The PVL genes were found in only five isolates belonging to unrelated lineages, ST8, ST30 and ST22, which could indicate at least three independent introductions of PVL(+) strains to Tenerife. Moreover, we detected that hospital MRSA clones, like EMRSA-15 and EMRSA-16, had spread to the community and are now circulating in both environments. Therefore, in our study, the CDC's rules were not specific enough to distinguish CA-MRSA from HA-MRSA. Thus, we think that the current epidemiological information is not enough to discriminate between both MRSAs, and it is necessary for prevention guidelines to include the routine determination of at least the genetic background, the antimicrobial susceptibility profile, and the PVL genes of each MRSA isolate.

  8. Molecular Characterization of Staphylococcus aureus Isolated from Meat and Their Antibiotic Resistance Profiles

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    Ziad W Jaradat

    2014-01-01

    Full Text Available The aims of this study were to characterize S. aureus isolates from different meat sources in Jordan and study their genetic relationship using PCR-RFLP in addition to their antibiotic resistance profiles. Thirty S. aureus isolates were identified and confirmed by PCR techniques. The isolates from goat and camel meats were sensitive to the majority of the tested antibiotics. Plasmid profiling revealed that 26 isolates contained at least one plasmid with no correlation between the number of plasmids and the resistance profiles. PCR-RFLP of the coagulase gene (coa classified the isolates to several clusters upon digestion with Alu I or Cfo I restriction enzymes. This study concluded that the 30 S. aureus isolates were genetically diverse and comprised heterogeneous population with 7 genotypes at both 33.1 and 51.2 similarity levels.

  9. Isolation and identification of antibiotic resistance genes in Staphylococcus aureus isolates from respiratory system infections in shahrekord, Iran

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    Maryam Reisi

    2014-07-01

    Full Text Available   Introduction : Staphylococcus aureus is considered as one of pathogenic agents in humans, that engages different body parts including respiratory system and causes to spend lots of costs and extending patient’s treatment period. This study which is performed to separate and investigate the pattern of antibiotic resistance in Staphylococcus aureus isolates from upper respiratory system infections in Shahrekord.   Materials and methods: This study was done by sectional-descriptive method On 200 suspicious persons to the upper respiratory system infections who were referred to the Imam Ali clinic in Shahrekord in 2012. After isolation of Staphylococcus aureus from cultured nose discharges, antibiotic resistance genes were identified by polymerase chain reaction (PCR by using defined primer pairs .   Results : Among 200 investigated samples in 60 cases (30% Staphylococcus aureus infection (by culturing and PCR method was determined. Isolates showed the lowest amount of antibiotic resistance to vancomycin (0.5% and the highest amount of resistance to the penicillin G and cefotaxime (100%. mecA gene (encoding methicillin resistance with frequency of 85.18% and aacA-D gene (encoding resistance to aminoglycosides with frequency of 28.33% showed the highest and lowest frequency of antibiotic resistance genes coding in Staphylococcus aureus isolates respectively .   Discussion and conclusion : Notable prevalence of resistant Staphylococcus aureus isolates in community acquired respiratory infections, recommend continuous control necessity to impede the spreading of these bacteria and their infections.  

  10. Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) isolates of swine origin form robust biofilms.

    Science.gov (United States)

    Nicholson, Tracy L; Shore, Sarah M; Smith, Tara C; Frana, Timothy S; Fraena, Timothy S

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) colonization of livestock animals is common and prevalence rates for pigs have been reported to be as high as 49%. Mechanisms contributing to the persistent carriage and high prevalence rates of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) strains in swine herds and production facilities have not been investigated. One explanation for the high prevalence of MRSA in swine herds is the ability of these organisms to exist as biofilms. In this report, the ability of swine LA-MRSA strains, including ST398, ST9, and ST5, to form biofilms was quantified and compared to several swine and human isolates. The contribution of known biofilm matrix components, polysaccharides, proteins and extracellular DNA (eDNA), was tested in all strains as well. All MRSA swine isolates formed robust biofilms similar to human clinical isolates. The addition of Dispersin B had no inhibitory effect on swine MRSA isolates when added at the initiation of biofilm growth or after pre-established mature biofilms formed. In contrast, the addition of proteinase K inhibited biofilm formation in all strains when added at the initiation of biofilm growth and was able to disperse pre-established mature biofilms. Of the LA-MRSA strains tested, we found ST398 strains to be the most sensitive to both inhibition of biofilm formation and dispersal of pre-formed biofilms by DNaseI. Collectively, these findings provide a critical first step in designing strategies to control or eliminate MRSA in swine herds.

  11. Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA isolates of swine origin form robust biofilms.

    Directory of Open Access Journals (Sweden)

    Tracy L Nicholson

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA colonization of livestock animals is common and prevalence rates for pigs have been reported to be as high as 49%. Mechanisms contributing to the persistent carriage and high prevalence rates of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA strains in swine herds and production facilities have not been investigated. One explanation for the high prevalence of MRSA in swine herds is the ability of these organisms to exist as biofilms. In this report, the ability of swine LA-MRSA strains, including ST398, ST9, and ST5, to form biofilms was quantified and compared to several swine and human isolates. The contribution of known biofilm matrix components, polysaccharides, proteins and extracellular DNA (eDNA, was tested in all strains as well. All MRSA swine isolates formed robust biofilms similar to human clinical isolates. The addition of Dispersin B had no inhibitory effect on swine MRSA isolates when added at the initiation of biofilm growth or after pre-established mature biofilms formed. In contrast, the addition of proteinase K inhibited biofilm formation in all strains when added at the initiation of biofilm growth and was able to disperse pre-established mature biofilms. Of the LA-MRSA strains tested, we found ST398 strains to be the most sensitive to both inhibition of biofilm formation and dispersal of pre-formed biofilms by DNaseI. Collectively, these findings provide a critical first step in designing strategies to control or eliminate MRSA in swine herds.

  12. Rapid first-line discrimination of methicillin resistant Staphylococcus aureus strains using MALDI-TOF MS

    DEFF Research Database (Denmark)

    Østergaard, Claus; Grønvall Kjær Hansen, Sanne; Møller, Jens K

    2015-01-01

    Fast and reliable discrimination of methicillin-resistant Staphylococcus aureus (MRSA) isolates is essential in identifying an outbreak. Molecular typing methods, such as S. aureus protein A (spa) typing, multi locus sequence typing (MLST) and pulse field gel electrophoresis (PFGE) are generally...... 600 clinical MRSA isolates were included in the study, representing 89 spa types, associated with 16 different known clonal complexes. All spectra were obtained directly from colony material obtained from overnight cultures without prior protein extraction. We identified 43 useful discriminatory m...

  13. Complete Genome Sequence of Staphylococcus aureus 6850, a Highly Cytotoxic and Clinically Virulent Methicillin-Sensitive Strain with Distant Relatedness to Prototype Strains

    NARCIS (Netherlands)

    Fraunholz, Martin; Bernhardt, Jörg; Schuldes, Jörg; Daniel, Rolf; Hecker, Michael; Sinha, Bhanu

    2013-01-01

    Staphylococcus aureus is a frequent human commensal bacterium and pathogen. Here we report the complete genome sequence of strain 6850 (spa type t185; sequence type 50 [ST50]), a highly cytotoxic and clinically virulent methicillin-sensitive strain from a patient with complicated S. aureus bacteremi

  14. Detection of Oxacillin Resistance in Staphylococcus aureus Isolated from the Neonatal and Pediatric Units of a Brazilian Teaching Hospital

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    Valéria Cataneli Pereira

    2009-01-01

    Full Text Available Objective: To determine, by phenotypic and genotypic methods, oxacillin susceptibility in Staphylococcus aureus strains isolated from pediatric and neonatal intensive care unit patients seen at the University Hospital of the Botucatu School of Medicine.Methods: A total of 100 S. aureus strains isolated from the following materials were studied: 25 blood cultures, 21 secretions, 12 catheters, 3 cannulae and one chest drain from 62 patients in the neonatal unit, and 36 blood cultures, one pleural fluid sample and one peritoneal fluid sample from 38 patients in the pediatric unit. Resistance of the S. aureus isolates to oxacillin was evaluated by the disk diffusion method with oxacillin (1 μg and cefoxitin (30 μg, agar screening test using Mueller-Hinton agar supplemented with 6 μg/ml oxacillin and 4% NaCl, and detection of the mecA gene by PCR. In addition, the isolates were tested for β-lactamase production using disks impregnated with Nitrocefin and hyperproduction of β-lactamase using amoxicillin (20 μg and clavulanic acid (10 μg disks.Results: Among the 100 S. aureus strains included in the study, 18.0% were resistant to oxacillin, with 16.1% MRSA being detected in the neonatal unit and 21.0% in the pediatric unit. The oxacillin (1 μg and cefoxitin (30 μg disk diffusion methods presented 94.4% and 100% sensitivity, respectively, and 98.8% specificity. The screening test showed 100% sensitivity and 98.8% specificity. All isolates produced β-lactamase and one of these strains was considered to be a hyperproducer.Conclusions: The 30 μg cefoxitin disk diffusion method presented the best result when compared to the 1 μg oxacillin disk. The sensitivity of the agar screening test was similar to that of the cefoxitin disk diffusion method and higher than that of the oxacillin disk diffusion method. We observed variations in the percentage of oxacillin-resistant isolates during the study period, with a decline over the last years which

  15. Production of staphylococcal enterotoxins in microbial broth and milk by Staphylococcus aureus strains harboring seh gene.

    Science.gov (United States)

    Schubert, Justyna; Podkowik, Magdalena; Bystroń, Jarosław; Bania, Jacek

    2016-10-17

    Twenty Staphylococcus aureus strains harboring seh gene, including one carrying also sec gene and 11 sea gene, were grown in BHI+YE broth and milk and were tested for SEA, SEC and SEH production. All strains decreased pH of BHI+YE broth at 24h and increased them at 48h. Seventeen S. aureus strains grown in milk changed pH for no >0.3 unit until 48h. Three other S. aureus strains significantly decreased pH during growth in milk. All S. aureus produced SEH in BHI+YE broth in amounts ranging from 95 to 1292ng/ml, and from 170 to 4158ng/ml at 24 and 48h, respectively. SEH production in milk by 17 strains did not exceed 23ng/ml at 24h and 36ng/ml at 48h. Three S. aureus strains able to decrease milk pH produced 107-3029ng/ml and 320-4246ng/ml of SEH in milk at 24 and 48h, respectively. These strains were grown in milk and BHI+YE broth with pH stabilized at values near neutral leading to a significant decrease of SEH production. Representative weak SEH producers were grown in milk at reduced pH resulting in moderate increase in SEH production. SEA was produced in milk by 10S. aureus strains at 24-151ng/ml at 24h, and 31-303ng/ml at 48h. SEA production in milk was higher or comparable as in BHI+YE broth in 3 strains and lower for remaining strains. Production of SEC by sec-positive S. aureus strains was lower in milk than in BHI+YE broth, ranging from 131 to 2319ng/ml at 24 and 48h in milk and 296-30,087ng/ml in BHI+YE at 24 and 48h. Both lacE and lacG transcripts involved in lactose metabolism were significantly up-regulated in milk in strong SEH producers. In these strains hld, rot and sarA transcripts were up-regulated in milk as compared to weak SEH producers. Stabilization of milk pH at a value of raw milk significantly down-regulated hld, rot and sarA RNA in strong SEH producers. Milk was generally found unfavorable for enterotoxin production. However, certain S. aureus strains were not restricted in SEH and SEA expression in milk, unlike SEC which remained down

  16. Isolation,Identification and Toxin Genes Detection of Staphylococcus aureus Strains from Infant Milk Powder and Infant Rice Cereal%婴幼儿奶粉和米粉中金黄色葡萄球菌的分离鉴定及其毒素基因检测

    Institute of Scientific and Technical Information of China (English)

    张静; 于三科; 王新; 乔明宇; 周婷; 夏效东; 杨保伟; 席美丽; 孟江洪

    2011-01-01

    Staphylococcus aureus;the nuc genes were examined to confirm Staphylococcus aureus status;Staphylococcus aureus enterotoxin genes,exfoliative toxins genes,toxic-shock syndrome toxin-1 gene and Panton-Valentine Leukocidin gene were detected by PCR.Results: Of 367 samples examined,30 were positive for Staphylococcus aureus,result in a positive rate of 8.17%(30/367),including 11.19%(16/143) milk powder samples and 6.25%(14/224) rice cereal samples.From these positive samples,29 and 25 strains were isolated from milk powder and rice cereal samples respectively.Among all identified Staphylococcus aureus isolates,34 strains harbored at least one of the tested toxin genes.The toxins gene profiles detected in S.aureus from infant milk powder samples were pvl,sea,seb,sec,sed,seg,seb+seg,sec+seg and seb+sed+seg,and their positive rates were 44.82%(13/29),10.34%(3/29),13.79%(4/29),17.24%(5/29),6.89%(2/29),41.38%(12/29),10.34%(3/29),10.34%(3/29) and 3.45%(1/29) respectively;The toxin gene profiles in S.aureus from infant rice cereal samples were pvl,sea,sec,sed,see,seg,sea+seg,sec+seg and sec+see+seg,and the positive rates were 36%(9/25),4%(1/25),20%(5/25),4%(1/25),12%(3/25),36%(9/25),4%(1/25),16%(4/25) and 8%(2/25),respectively.Neither ets,tsst-1,seh,sei nor sej genes were detected in infant milk powder or infant rice cereal.Conclusion: Infant milk powder and infant rice cereal in Shaanxi province were contaminated with S.aureus,some of which contained various toxin genes.The existence of the pathogen in these food products may constitute a potential risk for infants,health.

  17. Fatal S. aureus hemorrhagic pneumonia: genetic analysis of a unique clinical isolate producing both PVL and TSST-1.

    Directory of Open Access Journals (Sweden)

    Zhi Li

    Full Text Available In 2008, an unusual strain of methicillin-sensitive Staphylococcus aureus (MSSA68111, producing both Panton-Valentine leukocidin (PVL and toxic shock syndrome toxin-1 (TSST-1, was isolated from a fatal case of necrotizing pneumonia. Because PVL/TSST-1 co-production in S. aureus is rare, we characterized the molecular organization of these toxin genes in strain 68111. MSSA68111 carries the PVL genes within a novel temperate prophage we call ФPVLv68111 that is most similar, though not identical, to phage ФPVL--a phage type that is relatively rare worldwide. The TSST-1 gene (tst in MSSA68111 is carried on a unique staphylococcal pathogenicity island (SaPI we call SaPI68111. Features of SaPI68111 suggest it likely arose through multiple major recombination events with other known SaPIs. Both ФPVLv68111 and SaPI68111 are fully mobilizable and therefore transmissible to other strains. Taken together, these findings suggest that hypervirulent S. aureus have the potential to emerge worldwide.

  18. Biofilm formation by Staphylococcus aureus isolates from a dental clinic in Konya, Turkey.

    Science.gov (United States)

    Torlak, Emrah; Korkut, Emre; Uncu, Ali T; Şener, Yağmur

    2017-02-14

    The ability of Staphylococcus aureus to form biofilm is considered to be a major virulence factor influencing its survival and persistence in both the environment and the host. Biofilm formation in S. aureus is most frequently associated with production of polysaccharide intercellular adhesion by ica operon-encoded enzymes. The present work aimed at evaluating the in vitro biofilm production and presence of the icaA and icaD genes in S. aureus isolates from a dental clinic in Konya, Turkey. The surfaces of inanimate objects were sampled over a period of six months. S. aureus isolates were subjected to Congo Red Agar (CRA) and crystal violet (CV) staining assays to evaluate their ability of biofilm production, while the presence of the icaA and icaD genes was determined by polymerase chain reaction. S. aureus contamination was detected in 13.2% of the environmental samples. All the 32 isolates were observed to be positive for both the icaA and icaD genes. Phenotypic evaluations revealed that CV staining assay is a more reliable alternative to CRA assay to determine biofilm formation ability. A high percentage of agreement (91%) was observed between the results from CV staining and ica genes' detection assays. Phenotypic and genotypic evaluations should be combined to detect biofilm formation in S. aureus. Our findings indicate that dental clinic environments should be considered as potential reservoir for biofilm-producing S. aureus and thus cross contamination.

  19. Draft Genome Sequence of the Aureocin A53–Producing Strain Staphylococcus aureus A53

    Science.gov (United States)

    Santos, Olinda Cabral Silva; Duarte, Andreza Freitas Souza; Albano, Rodolpho Mattos

    2016-01-01

    Here, we present the 2,658,363-bp draft genome sequence of the aureocin A53–producing strain Staphylococcus aureus A53. This genome information may contribute to the optimal and rational exploitation of aureocin A53 as an antimicrobial agent and to its production in large scale. PMID:27563042

  20. Draft Genome Sequence of the Aureocin A53-Producing Strain Staphylococcus aureus A53.

    Science.gov (United States)

    Santos, Olinda Cabral Silva; Duarte, Andreza Freitas Souza; Albano, Rodolpho Mattos; Bastos, Maria Carmo Freire

    2016-08-25

    Here, we present the 2,658,363-bp draft genome sequence of the aureocin A53-producing strain Staphylococcus aureus A53. This genome information may contribute to the optimal and rational exploitation of aureocin A53 as an antimicrobial agent and to its production in large scale.

  1. Biofilm formation by Staphylococcus aureus isolates from skin and soft tissue infections.

    Science.gov (United States)

    Kwiecinski, Jakub; Kahlmeter, Gunnar; Jin, Tao

    2015-05-01

    Many diseases caused by Staphylococcus aureus are associated with biofilm formation. However, the ability of S. aureus isolates from skin and soft tissue infections to form biofilms has not yet been investigated. We tested 160 isolates from patients with various skin infections for biofilm-forming capacity in different growth media. All the isolates formed biofilms, the extent of which depended on the type of growth medium. The thickest biofilms were formed when both plasma and glucose were present in the broth; in this case, S. aureus incorporated host fibrin into the biofilm's matrix. There were no differences in the biofilm formation between isolates from different types of skin infections, except for a particularly good biofilm formation by isolates from diabetic wounds and a weaker biofilm formation by isolates from impetigo. In conclusion, biofilm formation is a universal behavior of S. aureus isolates from skin infections. In some cases, such as in diabetic wounds, a particularly strong biofilm formation most likely contributes to the chronic and recurrent character of the infection. Additionally, as S. aureus apparently uses host fibrin as part of the biofilm structure, we suggest that plasma should be included more frequently in in vitro biofilm studies.

  2. Antimicrobial susceptibility of Staphylococcus aureus and Staphylococcus pseudintermedius isolated from various animals.

    Science.gov (United States)

    Rubin, Joseph E; Ball, Katherine R; Chirino-Trejo, Manuel

    2011-02-01

    This study characterized the antimicrobial susceptibility of 221 Staphylococcus aureus isolated from various species, and 60 canine Staphylococcus pseudintermedius isolated from 1986 through 2000 at the Western College of Veterinary Medicine (WCVM). Resistance of S. aureus was most common to penicillin (31%) and tetracycline (14%); resistance of S. pseudintermedius to penicillin was present in 8% and to tetracycline in 34% of isolates. Resistance to trimethoprim/sulfamethoxazole was only seen among S. pseudintermedius, and there was no resistance to amoxicillin/clavulanate, ampicillin/sulbactam, cephalothin, amikacin, gentamicin, enrofloxacin, chloramphenicol, or rifampin among any isolate. Inducible clindamycin resistance was found in both S. aureus and S. pseudintermedius, highlighting the need for careful interpretation of culture and susceptibility test results. There were significant differences in the minimum inhibitory concentrations of penicillin, ciprofloxacin, enrofloxacin, clindamycin, erythromycin, chloramphenicol, and tetracycline between avian, bovine, equine, and porcine isolates.

  3. Associated risk factors and pulsed field gel electrophoresis of nasal isolates of Staphylococcus aureus from medical students in a tertiary hospital in Lagos, Nigeria

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    Solayide A. Adesida

    2007-02-01

    Full Text Available Staphylococcus aureus infections are growing problems worldwide with important implications in hospitals. The organism is normally present in the nasal vestibule of about 35% of apparently healthy individuals and its carriage varies between different ethnic and age groups. Staphylococcal nasal carriage among health workers is particularly important to establish new clones and track origin of infections during outbreak situations. To determine the carriage rate and compare the pulsed field gel patterns of the strains, nasal swabs were collected from 185 medical students in a teaching hospital in Lagos, Nigeria. Isolates of S. aureus were tested for heamolysin production, methicillin sensitivity and Pulsed Field Gel Electrophoresis (PFGE was performed. The results showed S.aureus nasal carrier rate of 14% with significant rate among males compared to females. All the isolates produced heamolysin. Antibiotic susceptibility pattern revealed that majority of the isolates was susceptible. Five strains (19% harboured resistant determinants to penicillin and tetracycline. None of the strains was resistant to methicillin. 44% of the isolates typed by PFGE had type B, the most predominant pulsotype. PFGE A clone exhibited a single resistance phenotype suggesting a strong clonal relationship that could punctual an outbreak in the hospital. The results speculate that nasal carriage among medical personnel could be a function of various risk factors. Personal hygiene and behaviour may however be the means to reducing colonization and spread of S.aureus in our hospitals.

  4. Identification and Characterization of Phage Variants of a Strain of Epidemic Methicillin-Resistant Staphylococcus aureus (EMRSA-15)

    Science.gov (United States)

    O'Neill, G. L.; Murchan, S.; Gil-Setas, A.; Aucken, H. M.

    2001-01-01

    EMRSA-15 is one of the most important strains of epidemic methicillin-resistant Staphylococcus aureus (EMRSA) found in the United Kingdom. It was originally characterized by weak lysis with phage 75 and production of enterotoxin C but not urease. Two variant strains of EMRSA-15 which show a broader phage pattern than the progenitor strain have emerged. A total of 153 recent clinical isolates representing classical EMRSA-15 (55 isolates) or these phage variants (98 isolates) were compared by SmaI macrorestriction profiles in pulsed-field gel electrophoresis (PFGE) as well as by urease and enterotoxin C production. Eight of the 98 isolates were shown to be other unrelated strains by both PFGE and their production of urease, a misidentification rate of 8% by phage typing. Seventy-one EMRSA-15 isolates were enterotoxin C negative, and the majority of these were sensitive to phage 81. Examination of PFGE profiles and Southern blotting studies suggest that the enterotoxin C gene locus is encoded on a potentially mobile DNA segment of ca. 15 kb. After elimination of the eight non-EMRSA-15 isolates, the remaining 145 were characterized by PFGE, yielding 22 profiles. All profiles were within five band differences of at least one other profile. Classical EMRSA-15 isolates showed nine PFGE profiles, with the majority of isolates (68%) in profile B1. Six of these nine PFGE profiles were unique to the classical EMRSA-15 isolates. Among the phage variants of EMRSA-15, 16 profiles were seen, but the majority of isolates (83%) fell into 1 of 4 profiles (B2, B3, B4, and B7) which correlated well with phage patterns. The most divergent PFGE profiles among the EMRSA-15 isolates had as many as 12 band differences from one another, suggesting that in examining isolates belonging to such a temporally and geographically disseminated epidemic strain, the range of PFGE profiles must be regarded as a continuum and analyzed by relating the profiles back to the most common or progenitor

  5. Epidemiology and genotypic characteristics of Methicillin-Resistant Staphylococcus aureus strains of porcine origin

    Science.gov (United States)

    The main goal of this study was to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA), particularly livestock-associated (LA)-MRSA in pigs and pork. Genotypic relatedness of isolates on-farm, at slaughter and retail was assessed. Paired nasal and peri-anal swab samples we...

  6. Fusidic acid resistance in Staphylococcus aureus nasal carriage strains in nine European countries.

    NARCIS (Netherlands)

    Heijer, C.D.J. den; Bijnen, E.M.E. van; Paget, W.J.; Stobberingh, E.E.

    2014-01-01

    Aim: To evaluate fusidic acid resistance pheno- and geno-typically in nasal carriage Staphylococcus aureus isolated from general practice patients in nine European countries. Materials & methods: Phenotypic fusidic acid resistance was determined by disc diffusion and MIC values, and genotypically by

  7. Fusidic acid resistance in Staphylococcus aureus nasal carriage strains in nine European countries

    NARCIS (Netherlands)

    Heijer, C.D. den; Bijnen, E.M. van; Paget, W.J.; Stobberingh, E.E.

    2014-01-01

    AIM: To evaluate fusidic acid resistance pheno- and geno-typically in nasal carriage Staphylococcus aureus isolated from general practice patients in nine European countries. MATERIALS & METHODS: Phenotypic fusidic acid resistance was determined by disc diffusion and MIC values, and genotypically by

  8. STAPHYLOCOCCUS AUREUS ISOLATES FROM CAMELS DIFFER IN COAGULASE PRODUCTION, GENOTYPE AND METHICILLIN RESISTANCE GENE PROFILES

    Directory of Open Access Journals (Sweden)

    Ziad Jaradat

    2013-06-01

    Full Text Available Accurate and rapid typing of S. aureus is crucial to the control of its infections and minimizing its leakage to the food chain. The primary purpose of this research was to isolate S. aureus from camels’ meat and nasal swabs and to characterize the isolates for coagulase production and the presence of methicillin gene using PCR-RFLP of coagulase gene. A total of 264 camel’s meat and nasal swabs were collected from abattoirs or meat markets and were used in the study. Ninety two percent of samples showed typical colonies of S. aureus on Baird-Parker agar with a mean count 2.5 × 104 ± 1.8 × 104 CFU g-1. Upon confirmation of the isolates using S. aureus specific thermonuclease gene (nuc PCR primers, only 64 isolates contained the specific product and thus were confirmed as S. aureus. However, when tested for the presence of coagulase gene, only 48 of them were positive while the other 16 were coagulase negative. Coagulase gene-RFLP revealed 19 distinct patterns when the gene was digested with Alu I and Cfo I. The typing revealed that the 48 classified isolates were genetically diverse and comprised a heterogeneous population with 14 genotypes at a 44.4% similarity level. When the coagulase positive isolates were tested for the presence of methicillin resistance (mec A gene, 37 of the isolates were positive while the other 11 isolates were negative. The high heterogeneity among S. aureus isolates might be due to cross contamination between camel carcasses in slaughter houses and from handlers and their utensils.

  9. Bacteriocin-producing strains of Lactobacillus plantarum inhibit adhesion of Staphylococcus aureus to extracellular matrix: quantitative insight and implications in antibacterial therapy.

    Science.gov (United States)

    Mukherjee, Sandipan; Ramesh, Aiyagari

    2015-12-01

    In the present study, the adhesion of bacteriocin-producing probiotic strains of Lactobacillus plantarum onto extracellular matrix (ECM) proteins such as collagen and mucin and their potential to prevent pathogen invasion onto the ECM was ascertained. Fluorescence-based in vitro assays indicated that L. plantarum strains CRA21, CRA38 and CRA52 displayed considerable adhesion to ECM molecules, which was comparable to the probiotic Lactobacillus rhamnosus GG. Flow cytometry-based quantitative assessment of the adhesion potential suggested that L. plantarum CRA21 exhibited superior adhesion onto the ECM as compared with other lactic acid bacteria strains. Furthermore, fluorescence-based assays suggested that the highest inhibition of Staphylococcus aureus adhesion onto collagen and mucin by bacteriocin-producing L. plantarum strains was observed in the exclusion mode as compared with the competition and displacement modes. This observation was supported by the higher binding affinity (k(d)) for the ECM exhibited by the L. plantarum strains as compared with S. aureus. Interestingly, a crude plantaricin A extract from food isolates of L. plantarum displayed potent antibacterial activity on ECM-adhered S. aureus cells. It is envisaged that the L. plantarum isolates displaying bacteriocinogenic and ECM-adhering traits can perhaps be explored to develop safe antibacterial therapeutic agents.

  10. Molecular characterization and antimicrobial susceptibility of nasal Staphylococcus aureus isolates from a Chinese medical college campus.

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    Jimei Du

    Full Text Available Staphylococcus aureus colonization and infection occur more commonly among persons living or working in crowded conditions, but characterization of S. aureus colonization within medical communities in China is lacking. A total of 144 (15.4%, 144/935 S. aureus isolates, including 28 (3.0%, 28/935 MRSA isolates, were recovered from the nares of 935 healthy human volunteers residing on a Chinese medical college campus. All S. aureus isolates were susceptible to vancomycin, quinupristin/dalfopristin and linezolid but the majority were resistant to penicillin (96.5%, ampicillin/sulbactam (83.3% and trimethoprim/sulfamethoxazole (93.1%. 82%, (23/28 of the MRSA isolates and 66% (77/116 of the MSSA isolates were resistant to multiple antibiotics, and 3 MRSA isolates were resistant to mupirocin--an agent commonly used for nasal decolonization. 16 different sequence types (STs, as well as SCCmec genes II, III, IVd, and V, were represented among MRSA isolates. We also identified, for the first time, two novel STs (ST1778 and ST1779 and 5 novel spa types for MRSA. MRSA isolates were distributed in different sporadic clones, and ST59-MRSA-VId- t437 was found within 3 MRSA isolates. Moreover, one isolate with multidrug resistance belonging to ST398-MRSA-V- t571 associated with animal infections was identified, and 3 isolates distributed in three different clones harbored PVL genes. Collectively, these data indicate a high prevalence of nasal MRSA carriage and molecular heterogeneity of S. aureus isolates among persons residing on a Chinese medical college campus. Identification of epidemic MRSA clones associated with community infection supports the need for more effective infection control measures to reduce nasal carriage and prevent dissemination of MRSA to hospitalized patients and health care workers in this community.

  11. Synergistic antimicrobial activity between pentacyclic triterpenoids and antibiotics against Staphylococcus aureus strains

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    Navaratnam Parasakthi

    2011-06-01

    Full Text Available Abstract Background There has been considerable effort to discover plant-derived antibacterials against methicillin-resistant strains of Staphylococcus aureus (MRSA which have developed resistance to most existing antibiotics, including the last line of defence, vancomycin. Pentacyclic triterpenoid, a biologically diverse plant-derived natural product, has been reported to show anti-staphylococcal activities. The objective of this study is to evaluate the interaction between three pentacyclic triterpenoid and standard antibiotics (methicillin and vancomycin against reference strains of Staphylococcus aureus. Methods and Results The activity of the standard antibiotics and compounds on reference methicillin-sensitive and resistant strains of S. aureus were determined using the macrodilution broth method. The minimum inhibitory concentration (MIC of the compounds was compared with that of the standard antibiotics. The interaction between any two antimicrobial agents was estimated by calculating the fractional inhibitory concentration (FIC index of the combination. The various combinations of antibiotics and compounds reduced the MIC to a range of 0.05 to 50%. Conclusion Pentacyclic triterpenoids have shown anti-staphylococcal activities and although individually weaker than common antibiotics produced from bacteria and fungi, synergistically these compounds may use different mechanism of action or pathways to exert their antimicrobial effects, as implicated in the lowered MICs. Therefore, the use of current antibiotics could be maintained in their combination with plant-derived antibacterial agents as a therapeutic option in the treatment of S. aureus infections.

  12. Synthesis and biofilm formation reduction of pyrazole-4-carboxamide derivatives in some Staphylococcus aureus strains.

    Science.gov (United States)

    Cascioferro, Stella; Maggio, Benedetta; Raffa, Demetrio; Raimondi, Maria Valeria; Cusimano, Maria Grazia; Schillaci, Domenico; Manachini, Barbara; Plescia, Fabiana; Daidone, Giuseppe

    2016-11-10

    The ability of several N-phenyl-1H-pyrazole-4-carboxamide derivatives and other pyrazoles opportunely modified at the positions 3, 4 and 5, to reduce the formation of the biofilm in some Staphylococcus aureus strains (ATCC 29213, ATCC 25923 and ATCC 6538) were investigated. All the tested compounds were able, although to a different extent, to reduce the biofilm formation of the three bacterial strains considered. Among these, the 1-(2,5-dichlorophenyl)-5-methyl-N-phenyl-1H-pyrazole-4-carboxamide 14 resulted as the best inhibitor of biofilm formation showing an IC50 ranging from 2.3 to 32 μM, against all the three strains of S. aureus. Compound 14 also shows a good protective effect in vivo by improving the survival of wax moth larva (Galleria mellonella) infected with S. aureus ATCC 29213. These findings indicate that 14d is a potential lead compound for the development of new anti-virulence agents against S. aureus infections.

  13. Frequency of Aminoglycoside-Resistance Genes in Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates from Hospitalized Patients

    Science.gov (United States)

    Mahdiyoun, Seyed Mohsen; Kazemian, Hossein; Ahanjan, Mohammad; Houri, Hamidreza; Goudarzi, Mehdi

    2016-01-01

    Background Staphylococcus aureus is one of the most important causative agents in community- and hospital-acquired infections. Aminoglycosides are powerful bactericidal drugs that are often used in combination with beta-lactams or glycopeptides to treat staphylococcal infections. Objectives The main objective of the present study was to determine the prevalence of aminoglycoside resistance among methicillin-resistant Staphylococcus aureus (MRSA) isolates in hospitalized patients in Sari and Tehran, Iran. Methods In this study, 174 MRSA strains isolated from different clinical samples, such as blood, sputum, tracheal exudates, bronchus, pleura, urine, wounds, and catheters, were collected from hospitalized patients in Tehran and Sari during 2014. Antibiotic susceptibility testing was performed against nine antibiotics with the Kirby-Bauer disk diffusion method according to CLSI guidelines. The MRSA strains were examined with oxacillin and cefoxitin disks. MRSA was then validated by detection of the mecA gene. PCR was used to evaluate the prevalence of the aminoglycoside-resistance genes aac (6’)-Ie/aph (2”), aph (3’)-IIIa, and ant (4’) among the MRSA isolates. Results The results of drug susceptibility testing showed that the highest rate of resistance was against erythromycin in Tehran (84.4%) and gentamicin (71.7%) in Sari. All isolates were sensitive to vancomycin, and all strains harbored the mecA gene. The aac (6’)-Ie/aph (2”), aph (3’)-IIIa, and ant (4’)-Ia genes were detected among 134 (77%), 119 (68.4%), and 122 (70.1%) of the isolates, respectively. Conclusions The present study showed a high prevalence of aminoglycoside-resistance genes among MRSA isolates in two cities in Iran.

  14. Detection of Intracellular Adhesion (ica Gene and Biofilm Formation Staphylococcus aureus Isolates from Clinical Blood Cultures

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    Mohsen Mirzaee

    2015-10-01

    Full Text Available Background: In fact the biofilms are composed of bacterial cells living inmulticellular structures such as tissues and organs embedded within a self-produced matrix of extracellular polymeric substance (EPS. Ability to attach and biofilm formation are the most important virulence factors Staphylococcus aureus isolates. The aims of this study were to detect intracellular adhesion (ica locus and its relation to the biofilm formation phenotype in clinical isolates of S. aureus isolated from bloodcultures.Methods: A total of 31 clinical S. aureus isolates were collected from Loghman Hospital of Tehran, Iran. In vitro biofilm formation ability was determined by microliter tissue culture plates. All clinical isolates were examined for determination the ica locus by using PCR method.Results: Twelve (38.7% of the isolates were strong biofilm producers. The results showed that 18(80.6% of the isolates carried icaD gene, whereas the prevalence of icaA, icaB and icaC were 51.6%, 45.1% and 77.4% respectively.Conclusions: S. aureus clinical isolates have different ability to form biofilm. This may be caused by the differences in the expression of biofilm related genes, genetic make-up and physiological conditions.

  15. Post-invasion events after infection with Staphylococcus aureus are strongly dependent on both the host cell type and the infecting S. aureus strain.

    Science.gov (United States)

    Strobel, M; Pförtner, H; Tuchscherr, L; Völker, U; Schmidt, F; Kramko, N; Schnittler, H-J; Fraunholz, M J; Löffler, B; Peters, G; Niemann, S

    2016-09-01

    Host cell invasion is a major feature of Staphylococcus aureus and contributes to infection development. The intracellular metabolically active bacteria can induce host cell activation and death but they can also persist for long time periods. In this study a comparative analysis was performed of different well-characterized S. aureus strains in their interaction with a variety of host cell types. Staphylococcus aureus (strains 6850, USA300, LS1, SH1000, Cowan1) invasion was compared in different human cell types (epithelial and endothelial cells, keratinocytes, fibroblasts, osteoblasts). The number of intracellular bacteria was determined, cell inflammation was investigated, as well as cell death and phagosomal escape of bacteria. To explain strain-dependent differences in the secretome, a proteomic approach was used. Barrier cells took up high amounts of bacteria and were killed by aggressive strains. These strains expressed high levels of toxins, and possessed the ability to escape from phagolysosomes. Osteoblasts and keratinocytes ingested less bacteria, and were not killed, even though the primary osteoblasts were strongly activated by S. aureus. In all cell types S. aureus was able to persist. Strong differences in uptake, cytotoxicity, and inflammatory response were observed between primary cells and their corresponding cell lines, demonstrating that cell lines reflect only partially the functions and physiology of primary cells. This study provides a contribution for a better understanding of the pathomechanisms of S. aureus infections. The proteomic data provide important basic knowledge on strains commonly used in the analysis of S. aureus-host cell interaction.

  16. Pulsed-field gel electrophoresis typing of Staphylococcus aureus isolates

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    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...

  17. [Behavior of different strains of Staphylococcus aureus against root canal filling cements].

    Science.gov (United States)

    Pumarola, J; Berástegui, E; Canalda, C; Brau, E

    1991-01-01

    The mean goal of this study is the determination of the conduct of 120 strains of Staphylococcus aureus against seven root canal sealers: Traitement Spad, Endométhasone, N2 Universal, AH26 with silver, Diaket-A, Tubli Seal and Sealapex. The agar diffusion test was employed in the determination of its bacterial growth inhibition. The results obtained have demonstrated values very different between the tested strains. Therefore we recommended to employ strains with reference in the investigation of the bacterial growth inhibition in order to repeat equal experimentation conditions.

  18. Prevalence, Molecular Characterization, and Antimicrobial Susceptibility of Methicillin-Resistant Staphylococcus aureus Isolated from Milk and Dairy Products.

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    Al-Ashmawy, Maha Abdou; Sallam, Khalid Ibrahim; Abd-Elghany, Samir Mohammed; Elhadidy, Mohamed; Tamura, Tomohiro

    2016-03-01

    The present work was undertaken to study the prevalence, molecular characterization, virulence factors, and antimicrobial susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) in raw milk and dairy products in Mansoura City, Egypt. MRSA was detected in 53% (106/200) among all milk and dairy products with prevalence rates of 75%, 65%, 40%, 50%, and 35% in raw milk, Damietta cheese, Kareish cheese, ice cream, and yogurt samples, respectively. The mean S. aureus counts were 3.49, 3.71, 2.93, 3.40, and 3.23 log10 colony-forming units (CFU)/g among tested raw milk, Damietta cheese, Kareish cheese, ice cream and yogurt, respectively, with an overall count of 3.41 log10 CFU/g. Interestingly, all recovered S. aureus isolates were genetically verified as MRSA strains by molecular detection of the mecA gene. Furthermore, genes encoding α-hemolysin (hla) and staphylococcal enterotoxins (sea, seb, sec) were detected in all isolates. The antimicrobial susceptibility pattern of recovered MRSA isolates against 13 tested antimicrobials revealed that the least effective drugs were penicillin G, cloxacillin, tetracycline, and amoxicillin with bacterial resistance percentages of 87.9%, 75.9%, 65.2%, and 55.6%, respectively. These findings suggested that milk and dairy products represent a potential infection risk threat of multidrug-resistant and toxigenic S. aureus in Egypt due to neglected hygienic practices during production, retail, or storage stages. These findings highlighted the crucial importance of applying more restrictive hygienic measures in dairy production in Egypt for food safety.

  19. Stably luminescent Staphylococcus aureus clinical strains for use in bioluminescent imaging.

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    Roger D Plaut

    Full Text Available In vivo bioluminescent imaging permits the visualization of bacteria in live animals, allowing researchers to monitor, both temporally and spatially, the progression of infection in each animal. We sought to engineer stably luminescent clinical strains of Staphylococcus aureus, with the goal of using such strains in mouse models. The gram-positive shuttle vector pMAD was used as the backbone for an integration plasmid. A chloramphenicol resistance gene, a modified lux operon from Photorhabdus luminescens, and approximately 650 bp of homology to the chromosome of the USA300 S. aureus strain NRS384 were added, generating plasmid pRP1195. Electroporation into strain RN4220 followed by temperature shift led to integration of pRP1195 into the chromosome. The integrated plasmid was transferred to clinical strains by phage transduction. Luminescent strains displayed no in vitro growth defects. Moreover, luminescence was stable in vitro after three rounds of subculture over 48 hours of growth in the absence of antibiotics. Mice were infected with a luminescent strain of NRS384 in skin and intravenous models. In a mouse skin model, luminescent bacteria were present in lesions that formed and cleared over the course of several days, and in an intravenous model, bacteria inoculated in the mouse tail vein were observed spreading to multiple tissues. No statistically significant difference in virulence was observed between NRS384 and the luminescent strain in either infection model. These preliminary data suggest that this luminescent USA300 strain is suitable for use in mouse models. Similar strains were engineered using other sequenced clinical strains. Because these strains are stably luminescent, they should prove useful in animal models of infection.

  20. Detection and identification of methicillin resistant and sensitive strains of Staphylococcus aureus using tandem measurements.

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    Guntupalli, Rajesh; Sorokulova, Iryna; Olsen, Eric; Globa, Ludmila; Pustovyy, Oleg; Moore, Timothy; Chin, Bryan; Barbaree, James; Vodyanoy, Vitaly

    2012-09-01

    Discrimination of methicillin resistant (MRSA) and sensitive (MSSA) strains of Staphylococcus aureus, was achieved by the specially selected lytic bacteriophage with a wide host range of S. aureus strains and a penicillin-binding protein (PBP 2a) specific antibody. A quartz crystal microbalance with dissipation monitoring (QCM-D) was employed to analyze bacteria-phage interactions. The lytic phages were transformed into phage spheroids by exposure to water-chloroform interface. Phage spheroid monolayers were transferred onto QCM-D sensors by Langmuir-Blodgett (LB) technique. Biosensors were tested in the flow mode with bacterial water suspensions, while collecting frequency and energy dissipation changes. Bacteria-spheroid interactions resulted in decreased resonance frequency and an increase in dissipation energy for both MRSA and MSSA strains. Following the bacterial binding, these sensors were further exposed to a flow of the penicillin-binding protein (PBP 2a) specific antibody conjugated latex beads. Sensors tested with MRSA responded to PBP 2a antibody beads; while sensors examined with MSSA gave no response. This experimental difference establishes an unambiguous discrimination between methicillin resistant and sensitive S. aureus strains. Both free and immobilized bacteriophages strongly inhibit bacterial growth on solid/air interfaces and in water suspensions. After lytic phages are transformed into spheroids, they retain their strong lytic activity and demonstrate high bacterial capture efficiency. The phage and phage spheroids can be used for screening and disinfection of antibiotic resistant bacteria. Other applications may include use on biosensors, bacteriophage therapy, and antimicrobial surfaces.

  1. Multiplex PCR for detection of superantigenic toxin genes in methicillin-sensitive and methicillin-resistant Staphylococcus aureus isolated from patients and carriers of a hospital in northeast Thailand.

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    Wongboot, Warawan; Chomvarin, Chariya; Engchanil, Chulapan; Chaimanee, Prajuab

    2013-07-04

    The aims of this study were to develop multiplex PCR for simultaneous detection of five superantigenic toxin genes (sea, seb, sec, sed and tst-1) in Staphylococcus aureus isolated from 149 clinical samples and nasal swabs from 201 healthy subjects in Thailand, and to compare prevalence and expression of those genes between methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA). The sensitivity of multiplex PCR was 10(3) CFU/ml (60 CFU/PCR reaction) for DNA templates extracted by both boiling and extraction methods. S. aureus strains from patients (65%) harbored more superantigenic toxin genes than healthy subjects (54%). MRSA (80%) isolated from patients harbored more superantigenic toxin genes than MSSA (52%). Sea was the most frequently found gene in S. aureus strains from patients and carriers. MRSAisolates harbored sea and produced SEA more frequently than MSSA isolates (p <0.05) and MRSA isolates (59%) from blood samples consisted of a higher number of superantigenic toxin producers than MSSA (9%) (p < 0.05). More S. aureus strains isolated from patients with severe septicemia contained superantigenic toxin genes (94%) and produced toxins (82%) than those from non-severe patients (64% and 57%, respectively). The multiplex PCR method described here offers a reliable tool for simultaneous detection of various staphylococcal toxin genes.

  2. Molecular characterisation of Panton–Valentine leucocidin-producing methicillin-resistant Staphylococcus aureus clones isolated from the main hospitals in Taif, KSA

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    E M Eed

    2016-01-01

    Full Text Available Introduction: Panton–Valentine leucocidin (PVL is a bicomponent pore-forming cytolytic toxin encoded by the lukF-PV and lukS-PV genes. Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA may carry the pvl genes which may be related to increased disease severity. This study aimed to characterise the PVL-producing MRSA recovered from different Taif Hospitals, Saudi Arabia. Methods: The study included 45 hospital-acquired-MRSA (HA-MRSA and 26 CA-MRSA strains which were identified from 445 S. aureus strains isolated from different clinical samples. MRSA strains were identified by standard oxacillin salt agar screening procedure and by the detection of the mecA gene by the polymerase chain reaction (PCR. Detection of the S. aureus-specific femA, mecA and pvl genes was performed by multiplex PCR. PCR-restriction fragment length polymorphism (PCR-RFLP analysis was done for coagulase (coa gene. Results: The staphylococcal cassette chromosome mec types of the 45 HA-MRSA strains were Type I (n = 24, Type II (n = 7 and Type III (n = 14 whereas the 26 CA-MRSA strains were Type IV (n = 14, Type V (n = 11 and one isolate was non-typeable. All the HA-MRSA and six CA-MRSA strains were PVL-negative PCR-RFLP analysis of coa gene showed that PVL-positive MRSA (n = 20 isolates showed six different patterns, and five patterns were shared by PVL-positive methicillin-susceptible S. aureus (MSSA. The eighth pattern was the most frequent in both MRSA and MSSA. Conclusion: PVL is more frequent among CA-MRSA than MSSA. All the HA-MRSA and 25% of CA-MRSA strains were negative for PVL. The pvl gene was related to the severity of infection but not related to coa gene RFLP pattern.

  3. Shewanella strain isolated from black powder

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    Lutterbach, Marcia T.S.; Contador, Luciana S.; Oliveira, Ana Lucia C.; Galvao, Mariana M. [National Institute of Technology (INT), Rio de Janeiro, RJ (Brazil); Pimenta, Gutemberg S. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    Black powder is a term frequently used to refer to residues formed by various types of iron sulfides mixed with contaminants eventually present in the natural gas flow. According to some researchers, the occurrence of black powder in gas pipelines, besides its chemical corrosion origin, can be directly related to the sulfate-reducing bacteria (SRB) metabolism in this environment. A black powder sample was inoculated in a Post gate E medium modified with the addition of thioglycolate. The resulting positive culture was kept in the laboratory for four years until its use. A dilution technique was then performed aiming to isolate an SRB strain. The bacterial strain isolated and identified through DNA sequencing was not an SRB but rather a Shewanella sp. Compared to the sulfate-reducing bacteria group-traditionally considered the foremost responsible for microbially-influenced corrosion (MIC) - Shewanella is a facultative anaerobe and has a versatile metabolism. Shewanella is able to reduce ferric iron and sulfite, oxidize hydrogen gas, and produce hydrogen sulfide; therefore, these bacteria can be responsible for MIC and pit formation. The isolated Shewanella was used in a corrosion experiment, and the corrosion products were characterized by X-ray diffraction, identifying iron sulfides, iron oxides, and sulfur. Our results indicate that the strain isolated, S. putrefaciens, plays a key role in corrosion problems in gas pipelines. (author)

  4. Necrotizing fasciitis caused by Staphylococcus aureus: the emergence of methicillin-resistant strains.

    Science.gov (United States)

    Cheng, Nai-Chen; Wang, Jann-Tay; Chang, Shan-Chwen; Tai, Hao-Chih; Tang, Yueh-Bih

    2011-12-01

    Staphylococcus aureus is an uncommon causative agent of monomicrobial necrotizing fasciitis, but we have noted several cases over the years. The patients treated for necrotizing fasciitis between January 1998 and December 2008 in our institution were identified, and their medical records were reviewed. Of 105 necrotizing fasciitis cases during the study period, 18 were caused by monomicrobial S. aureus infection (17%). The median age was 62 years (range, 12-81 years). Among this cohort, 10 patients had coexisting medical conditions or risk factors, including diabetes and hypertension. Lower limbs and upper limbs are the most commonly involved sites. Among the bacterial isolates from these cases, 8 were methicillin-sensitive S. aureus (MSSA) and 10 were methicillin-resistant S. aureus (MRSA). One patient died in the MSSA group, and 5 patients died in the MRSA group. The mortality rate and other clinical characteristics were not significantly different between the 2 groups. However, all MRSA necrotizing fasciitis developed after the year 2000, and it was significantly different from MSSA necrotizing fasciitis that predominantly took place before the year 2000. In conclusion, S. aureus is an important pathogen of monomicrobial necrotizing fasciitis, and MRSA has emerged as the predominant causative agent in recent years. Therefore, MRSA-directed antibiotic therapy should be considered when treating patients suspected with necrotizing fasciitis in endemic areas.

  5. Structural features of piperazinyl-linked ciprofloxacin dimers required for activity against drug-resistant strains of Staphylococcus aureus.

    Science.gov (United States)

    Kerns, Robert J; Rybak, Michael J; Kaatz, Glenn W; Vaka, Flamur; Cha, Raymond; Grucz, Richard G; Diwadkar, Veena U

    2003-07-07

    We previously demonstrated that piperazinyl-linked fluoroquinolone dimers possess potent antibacterial activity against drug-resistant strains of Staphylococcus aureus. In this study, we report the preparation and evaluation of a series of incomplete dimers toward ascertaining structural features of piperazinyl-linked ciprofloxacin dimers that render these agents refractory to fluoroquinolone-resistance mechanisms in Staphylococcus aureus.

  6. Characterization of colonizing Staphylococcus aureus isolated from surgical wards' patients in a Nigerian university hospital.

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    Deboye O Kolawole

    Full Text Available In contrast to developed countries, only limited data on the prevalence, resistance and clonal structure of Staphylococcus aureus are available for African countries. Since S. aureus carriage is a risk factor for postoperative wound infection, patients who had been hospitalized in surgical wards in a Nigerian University Teaching Hospital were screened for S. aureus carriage. All S. aureus isolates were genotyped (spa, agr and assigned to multilocus sequence types (MLST. Species affiliation, methicillin-resistance, and the possession of pyrogenic toxin superantigens (PTSAg, exfoliative toxins (ETs and Panton-Valentine Leukocidin (PVL were analyzed. Of 192 patients screened, the S. aureus carrier rate was 31.8 % (n = 61. Of these isolates, 7 (11.5% were methicillin-resistant (MRSA. The isolates comprised 24 spa types. The most frequent spa types were t064, t084, t311, and t1931, while the most prevalent MLST clonal complexes were CC5 and CC15. The most frequent PTSAg genes detected were seg/sei (41.0% followed by seb (29.5%, sea (19.7%, seh (14.7% and sec (11.5. The difference between the possession of classical and newly described PTSAg genes was not significant (63.9% versus 59.0% respectively; P = 0.602. PVL encoding genes were found in 39.3% isolates. All MRSA isolates were PVL negative, SCCmec types I and VI in MLST CC 5 and CC 30, respectively. Typing of the accessory gene regulator (agr showed the following distribution: agr group 1 (n = 20, group II (n = 17, group III (n = 14 and group IV (n = 10. Compared to European data, enterotoxin gene seb and PVL-encoding genes were more prevalent in Nigerian methicillin-susceptible S. aureus isolates, which may therefore act as potential reservoir for PVL and PTSAg genes.

  7. Comparison of Staphylococcus aureus isolates associated with food intoxication with isolates from human nasal carriers and human infections.

    Science.gov (United States)

    Wattinger, L; Stephan, R; Layer, F; Johler, S

    2012-04-01

    Staphylococcus aureus represents an organism of striking versatility. While asymptomatic nasal colonization is widespread, it can also cause serious infections, toxinoses and life-threatening illnesses in humans and animals. Staphylococcal food poisoning (SFP), one of the most prevalent causes of foodborne intoxication worldwide, results from oral intake of staphylococcal enterotoxins leading to violent vomiting, diarrhea and cramps shortly upon ingestion. The aim of the present study was to compare isolates associated with SFP to isolates collected from cases of human nasal colonization and clinical infections in order to investigate the role of S. aureus colonizing and infecting humans as a possible source of SFP. Spa typing and DNA microarray profiling were used to characterize a total of 120 isolates, comprising 50 isolates collected from the anterior nares of healthy donors, 50 isolates obtained from cases of clinical infections in humans and 20 isolates related to outbreaks of staphylococcal food poisoning. Several common spa types were found among isolates of all three sources (t015, t018, t056, t084). DNA microarray results showed highly similar virulence gene profiles for isolates from all tested sources. These results suggest contamination of foodstuff with S. aureus colonizing and infecting food handlers to represent a source of SFP.

  8. A Staphylococcus aureus Proteome Overview: Shared and Specific Proteins and Protein Complexes from Representative Strains of All Three Clades.

    Science.gov (United States)

    Liang, Chunguang; Schaack, Dominik; Srivastava, Mugdha; Gupta, Shishir K; Sarukhanyan, Edita; Giese, Anne; Pagels, Martin; Romanov, Natalie; Pané-Farré, Jan; Fuchs, Stephan; Dandekar, Thomas

    2016-02-19

    Staphylococcus aureus is an important model organism and pathogen. This S. aureus proteome overview details shared and specific proteins and selected virulence-relevant protein complexes from representative strains of all three major clades. To determine the strain distribution and major clades we used a refined strain comparison combining ribosomal RNA, MLST markers, and looking at highly-conserved regions shared between strains. This analysis shows three sub-clades (A-C) for S. aureus. As calculations are complex and strain annotation is quite time consuming we compare here key representatives of each clade with each other: model strains COL, USA300, Newman, and HG001 (clade A), model strain N315 and Mu50 (clade B) and ED133 and MRSA252 (clade C). We look at these individual proteomes and compare them to a background of 64 S. aureus strains. There are overall 13,284 S. aureus proteins not part of the core proteome which are involved in different strain-specific or more general complexes requiring detailed annotation and new experimental data to be accurately delineated. By comparison of the eight representative strains, we identify strain-specific proteins (e.g., 18 in COL, 105 in N315 and 44 in Newman) that characterize each strain and analyze pathogenicity islands if they contain such strain-specific proteins. We identify strain-specific protein repertoires involved in virulence, in cell wall metabolism, and phosphorylation. Finally we compare and analyze protein complexes conserved and well-characterized among S. aureus (a total of 103 complexes), as well as predict and analyze several individual protein complexes, including structure modeling in the three clades.

  9. A Novel Repressor of the ica Locus Discovered in Clinically Isolated Super-Biofilm-Elaborating Staphylococcus aureus

    Science.gov (United States)

    Yu, Liansheng; Hisatsune, Junzo; Hayashi, Ikue; Tatsukawa, Nobuyuki; Sato’o, Yusuke; Mizumachi, Emiri; Kato, Fuminori; Hirakawa, Hideki; Pier, Gerald B.

    2017-01-01

    ABSTRACT Staphylococcus aureus TF2758 is a clinical isolate from an atheroma and a super-biofilm-elaborating/polysaccharide intercellular adhesin (PIA)/poly-N-acetylglucosamine (PNAG)-overproducing strain (L. Shrestha et al., Microbiol Immunol 60:148–159, 2016, https://doi.org/10.1111/1348-0421.12359). A microarray analysis and DNA genome sequencing were performed to identify the mechanism underlying biofilm overproduction by TF2758. We found high transcriptional expression levels of a 7-gene cluster (satf2580 to satf2586) and the ica operon in TF2758. Within the 7-gene cluster, a putative transcriptional regulator gene designated rob had a nonsense mutation that caused the truncation of the protein. The complementation of TF2758 with rob from FK300, an rsbU-repaired derivative of S. aureus strain NCTC8325-4, significantly decreased biofilm elaboration, suggesting a role for rob in this process. The deletion of rob in non-biofilm-producing FK300 significantly increased biofilm elaboration and PIA/PNAG production. In the search for a gene(s) in the 7-gene cluster for biofilm elaboration controlled by rob, we identified open reading frame (ORF) SAOUHSC_2898 (satf2584). Our results suggest that ORF SAOUHSC_2898 (satf2584) and icaADBC are required for enhanced biofilm elaboration and PIA/PNAG production in the rob deletion mutant. Rob bound to a palindromic sequence within its own promoter region. Furthermore, Rob recognized the TATTT motif within the icaR-icaA intergenic region and bound to a 25-bp DNA stretch containing this motif, which is a critically important short sequence regulating biofilm elaboration in S. aureus. Our results strongly suggest that Rob is a long-sought repressor that recognizes and binds to the TATTT motif and is an important regulator of biofilm elaboration through its control of SAOUHSC_2898 (SATF2584) and Ica protein expression in S. aureus. PMID:28143981

  10. Detection of classical genes and enterotoxins of Staphylococcus aureus isolated from raw milk in the south-east region of Poland

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    Korpysa-Dzirba Weronika

    2014-12-01

    Full Text Available The aim of the study was to investigate if the enterotoxigenic strains of S. aureus isolated from raw milk are able to produce staphylococcal enterotoxins (SEs A - E. A total of 168 of S. aureus isolates from raw milk collected in the south - east region of Poland (Lubelskie Province were tested for SE production by the ELFA, while multiplex PCR was applied for detection of enterotoxin genes (sea, seb, sec, sed, see. It was found that 20 (11.9% out of 168 strains were positive for one or more classical SE markers and 19 of them produced a detectable level of enterotoxins. The results obtained by mPCR and ELFA were in agreement, when the presence of A, B, and D toxin types was tested; whereas SEC was not found by the ELFA although the S. aureus was positive for the respective gene. The results of the two methods showed that mPCR identified one more strain potentially producing enterotoxin than the ELFA, which may suggest that the enterotoxigenic S. aureus are not always able to express the toxin protein.

  11. Polymorphism, genetic exchange and intragenic recombination of the aureolysin gene among Staphylococcus aureus strains

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    Kowal Julia

    2008-07-01

    Full Text Available Abstract Background Staphylococcus aureus expresses several proteases, which are thought to contribute to the virulence of this bacterium. Here we focus on aureolysin, the major thermolysin-like metalloprotease. Despite the importance of aureolysin in the physiology and pathogenesis of S. aureus, relatively little information was so far available concerning the aur gene diversity and mobility within and between the major subdivisions of the S. aureus population. Therefore, an epidemiologically and genetically diverse collection of S. aureus strains was used to determine the range of aureolysin (aur gene polymorphism. Results Sequence analyses support the conclusion that the aur gene occurs in two distinct types of related sequences. The aur gene was much more polymorphic but, at the same time, showed higher purifying selection than genes utilized for multilocus sequence typing (MLST. Gene trees constructed from aur and concatenated MLST genes revealed several putative assortative recombination events (i.e. entire aur gene exchanges between divergent lineages of S. aureus. Evidence for intragenic recombination events (i.e. exchanges of internal aur segments across aur genes was also found. The biochemical properties and substrate specificity of the two types of aureolysin purified to homogeneity were studied, revealing minor differences in their affinity to low molecular weight synthetic substrates. Conclusion Although numerous nucleotide differences were identified between the aur alleles studied, our findings showed that a strong purifying selection is acting on the aur gene. Moreover, our study distinguishes between homologous exchanges of the entire aur gene (assortative recombination between divergent S. aureus lineages and recombination events within aur genes.

  12. Impact of individual extracellular proteases on Staphylococcus aureus biofilm formation in diverse clinical isolates and their isogenic sarA mutants.

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    Loughran, Allister J; Atwood, Danielle N; Anthony, Allison C; Harik, Nada S; Spencer, Horace J; Beenken, Karen E; Smeltzer, Mark S

    2014-12-01

    We demonstrate that the purified Staphylococcus aureus extracellular proteases aureolysin, ScpA, SspA, and SspB limit biofilm formation, with aureolysin having the greatest impact. Using protease-deficient derivatives of LAC, we confirmed that this is due to the individual proteases themselves. Purified aureolysin, and to a lesser extent ScpA and SspB, also promoted dispersal of an established biofilm. Mutation of the genes encoding these proteases also only partially restored biofilm formation in an FPR3757 sarA mutant and had little impact on restoring virulence in a murine bacteremia model. In contrast, eliminating the production of all of these proteases fully restored both biofilm formation and virulence in a sarA mutant generated in the closely related USA300 strain LAC. These results confirm an important role for multiple extracellular proteases in S. aureus pathogenesis and the importance of sarA in repressing their production. Moreover, purified aureolysin limited biofilm formation in 14 of 15 methicillin-resistant isolates and 11 of 15 methicillin-susceptible isolates, while dispersin B had little impact in UAMS-1, LAC, or 29 of 30 contemporary isolates of S. aureus. This suggests that the role of sarA and its impact on protease production is important in diverse strains of S. aureus irrespective of their methicillin resistance status.

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

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    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

  14. Biochemical characters and antibiotic susceptibility of Staphylococcus aureus isolates

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    Subhankari Prasad Chakraborty

    2011-06-01

    Conclusions: These findings show that all these isolates have gelatin, urea, galactose hydrolysis and lactose fermenting activity. 20% of these isolates were resistant to kanamycin and 46.67% were resistant to oxacillin.

  15. Draft Genome Sequences of 15 Staphylococcus aureus Isolates Recovered from Raw Milk and Associated Milk Filters from Victoria, Australia

    Science.gov (United States)

    McMillan, Kate; Allnutt, Theodore R.

    2017-01-01

    ABSTRACT This study describes draft whole genomes of 15 Staphylococcus aureus isolates from dairy farms located in Victoria, Australia. Two novel sequence types (ST3183 and ST3184) were identified among these isolates. PMID:28082499

  16. Antimicrobial resistance and virulence markers in methicillin sensitive Staphylococcus aureus isolates associated with nasal colonization.

    Science.gov (United States)

    Sarkar, Abdullah; Raji, Adeola; Garaween, Ghada; Soge, Olusegun; Rey-Ladino, Jose; Al-Kattan, Wael; Shibl, Atef; Senok, Abiola

    2016-04-01

    Most Staphylococcus aureus infections occur in previously colonized persons who also act as reservoirs for continued dissemination. This study aimed to investigate the carriage of antimicrobial resistance and virulence markers in S. aureus isolates associated with nasal colonization. The study was conducted from December 2013-April 2014. Nasal swabs were collected and questionnaires administered to 97 medical students in Riyadh Saudi Arabia. Bacterial culture, identification and antimicrobial susceptibility testing were performed by conventional methods and chromogenic agar was used for methicillin resistant S. aureus (MRSA) screening. Molecular characterization of isolates was carried out using the StaphyType DNA microarray. Thirty two students (43%) had S. aureus nasal carriage (MSSA = 31; MRSA = 1). Seventeen clonal complexes (CC) were identified namely: CC15-MSSA (n = 5), CC1-MSSA-SCCfus (n = 4), CC8-MSSA (n = 3), CC22-MSSA (n = 3), CC25-MSSA (n = 3), CC101-MSSA (n = 2). Other CC found as single isolates were CC5-MSSA, CC6-MSSA, CC30-MSSA, CC45-MSSA, CC96-MSSA, CC188-MSSA, CC398-MSSA, CC942-MSSA/PVL+, CC1290-MSSA, ST2482-MSSA, CC80-MRSA-IV/PVL+. The CC1-SCCfus isolates harbored the Staphylococcal cassette chromosome (SCC) with ccrA-1; ccrB-1 and ccrB-3 genes plus the putative fusidic acid resistance marker Q6GD50. One MSSA isolate was genotyped as coagulase negative Staphylococcus spp with an irregular composite SCCmec element. Majority of the isolates harbored various virulence genes including the hemolysin, enterotoxin, and exfoliative genes as well as various adhesive protein producing genes. Although there was low carriage of MRSA, the MSSA isolates harbored various resistance and virulence genes including those usually seen in MRSA isolates. The presence of isolates with incomplete SCCmec elements plus putative resistance and virulence genes is of concern.

  17. Exploring the contribution of efflux on the resistance to fluoroquinolones in clinical isolates of Staphylococcus aureus

    LENUS (Irish Health Repository)

    Costa, Sofia SANTOS

    2011-10-27

    Abstract Background Antimicrobial resistance mediated by efflux systems is still poorly characterized in Staphylococcus aureus, despite the description of several efflux pumps (EPs) for this bacterium. In this work we used several methodologies to characterize the efflux activity of 52 S. aureus isolates resistant to ciprofloxacin collected in a hospital in Lisbon, Portugal, in order to understand the role played by these systems in the resistance to fluoroquinolones. Results Augmented efflux activity was detected in 12 out of 52 isolates and correlated with increased resistance to fluoroquinolones. Addition of efflux inhibitors did not result in the full reversion of the fluoroquinolone resistance phenotype, yet it implied a significant decrease in the resistance levels, regardless of the type(s) of mutation(s) found in the quinolone-resistance determining region of grlA and gyrA genes, which accounted for the remaining resistance that was not efflux-mediated. Expression analysis of the genes coding for the main efflux pumps revealed increased expression only in the presence of inducing agents. Moreover, it showed that not only different substrates can trigger expression of different EP genes, but also that the same substrate can promote a variable response, according to its concentration. We also found isolates belonging to the same clonal type that showed different responses towards drug exposure, thus evidencing that highly related clinical isolates may diverge in the efflux-mediated response to noxious agents. The data gathered by real-time fluorometric and RT-qPCR assays suggest that S. aureus clinical isolates may be primed to efflux antimicrobial compounds. Conclusions The results obtained in this work do not exclude the importance of mutations in resistance to fluoroquinolones in S. aureus, yet they underline the contribution of efflux systems for the emergence of high-level resistance. All together, the results presented in this study show the potential

  18. Low occurrence of the new species Staphylococcus argenteus in a Staphylococcus aureus collection of human isolates from Belgium.

    Science.gov (United States)

    Argudín, M A; Dodémont, M; Vandendriessche, S; Rottiers, S; Tribes, C; Roisin, S; de Mendonça, R; Nonhoff, C; Deplano, A; Denis, O

    2016-06-01

    Staphylococcus argenteus is a novel Staphylococcus species closely related to Staphylococcus aureus that has been recently described. In this study, we investigated the proportion and the characteristics of S. argenteus recovered from humans in Belgium. S. aureus. human isolates collected in Belgium from 2006 to 2015 (n = 1,903) were retrospectively characterised via the presence of non-pigmented colonies on chocolate agar, spa typing and rpoB sequencing to determine if some of them were in fact S. argenteus. Out of 73 strains non-pigmented on chocolate plates, 3 isolates (0.16 %) showed rpoB sequences, in addition to spa and sequence types (ST2250/t5787, ST2250/t6675, ST3240/t6675), related to S. argenteus. Two of them were methicillin-resistant, harbouring a SCCmec type IV. The three S. argenteus isolates carried genes (sak, scn) of the immune evasion cluster. This first Belgian nationwide analysis showed a low occurrence of S. argenteus. Further studies should be conducted to identify the distribution range and the clinical impact of this new species.

  19. Phenotypic and genotypic antimicrobial resistance traits of foodborne Staphylococcus aureus isolates from Shanghai.

    Science.gov (United States)

    Xu, Jie; Shi, Chunlei; Song, Minghui; Xu, Xuebin; Yang, Puyu; Paoli, George; Shi, Xianming

    2014-04-01

    Staphylococcus aureus is a recognized pathogen in humans, which causes nosocomial infections and food poisoning. The transmission of antibiotic resistant S. aureus (ARSA), especially methicillin-resistant S. aureus, between food products and humans has become a serious problem. Hence, it is necessary to monitor S. aureus through the food supply chain. In this study, the disk diffusion method and epsilometer test were performed to determine the prevalence of ARSA in 78 foodborne isolates using 18 antibiotics. The highest resistance frequency was found for penicillin G (74.4%), followed by erythromycin (59.0%) and clindamycin (44.9%), whereas no vancomycin-resistant isolates were found. The 78 isolates could be subtyped into 31 resistance profiles and 11 clusters based on their antimicrobial susceptibility. Furthermore, Polymerase chain reaction (PCR) screening for the presence of 13 genes conferring antibiotic resistance was conducted. The presence of resistance genes was relatively high: blaTEM (80.8%), ermB (41.0%), grlA (38.5%), ermC (35.9%), and aac6'/aph2" (35.9%). The incidence of antibiotic resistance was significantly correlated to food types (p = 0.018), with isolates from meat and raw milk more resistant to antibiotics than those from frozen food and vegetables.

  20. Staphylococcus aureus isolates from chronic osteomyelitis are characterized by high host cell invasion and intracellular adaptation, but still induce inflammation.

    Science.gov (United States)

    Kalinka, Julia; Hachmeister, Marie; Geraci, Jennifer; Sordelli, Daniel; Hansen, Uwe; Niemann, Silke; Oetermann, Sylvia; Peters, Georg; Löffler, Bettina; Tuchscherr, Lorena

    2014-11-01

    Osteomyelitis is a severe inflammatory disease of the bone that is mainly caused by Staphylococcus aureus. Particularly, bone infections are difficult to treat and can develop into a chronic course with a high relapsing rate despite of antimicrobial treatments. The complex interaction of staphylococci with osseous tissue and the bacterial ability to invade host cells are thought to determine the severity of infection. Yet, defined bacterial virulence factors responsible for the pathogenesis of osteomyelitis have not been clearly identified. The aim of this study was to detect S. aureus virulence factors that are associated with osteomyelitis and contribute to a chronic course of infection. To this purpose, we collected 41 S. aureus isolates, each 11 from acute osteomyelitis (infection period less than 2 months), 10 from chronic osteomyelitis (infection period more than 12 months), 10 from sepsis and 10 from nasal colonization. All isolates were analyzed for gene expression and in functional in-vitro systems. Adhesion assays to bone matrix revealed that all isolates equally bound to matrix structures, but invasion assays in human osteoblasts showed a high invasive capacity of chronic osteomyelitis isolates. The high invasion rate could not be explained by defined adhesins, as all infecting strains expressed a multitude of adhesins that act together and determine the level of adhesion. Following host cell invasion isolates from chronic osteomyelitis induced less cytotoxicity than all other isolates and a higher percentage of Small-colony-variant (SCV)-formation, which represents an adaptation mechanism during long-term persistence. Isolates from acute and chronic osteomyelitis strongly produced biofilm and highly expressed agr and sarA that regulate secreted virulence factors and induced an inflammatory response in osteoblasts. In conclusion, chronic osteomyelitis isolates were characterized by a high host cell invasion rate, low cytotoxicity and the ability to

  1. Short communication: prevalence and antibiotic resistance of Staphylococcus aureus isolated from bovine clinical mastitis.

    Science.gov (United States)

    Jamali, Hossein; Radmehr, Behrad; Ismail, Salmah

    2014-01-01

    The aims of this study were to determine the prevalence and antibiotic resistance of Staphylococcus aureus isolated from bovine clinical mastitis in Varamin, Tehran Province, Iran. All of the isolated Staph. aureus were identified by morphology and culture and confirmed using the API Staph identification system (bioMérieux, Marcy-l'Étoile, France). Antibiotic resistance genes were detected by PCR with oligonucleotide primers specific for each gene. Staphylococcus aureus was recovered from 43 of 207 (20.1%) bovine clinical milk samples. Using disk diffusion, methicillin-resistant Staph. aureus was detected in 5 of 43 (11.6%) samples. The pathogen showed high resistance against penicillin G (86%) and tetracycline (76.7%). The blaZ (penicillin) (86%), tetM (tetracycline), and ermC (erythromycin) genes (39.5% each) were the most prevalent antibiotic resistance genes. The findings of this study are useful for designing specific control programs for bovine clinical mastitis caused by Staph. aureus in this region of Iran.

  2. TSST-1, enterotoxin and bacteriocin-like substance production by Staphylococcus aureus isolated from foods

    Directory of Open Access Journals (Sweden)

    S.A. Carvalho

    2013-10-01

    Full Text Available The production of Toxic Shock Syndrome Toxin-1 (TSST-1, enterotoxins and bacteriocin-like substances was evaluated in 95 strains of Staphylococcus aureus recovered from raw bovine milk (n=31 and from food samples involved in staphylococcal food poisoning (n=64. Enterotoxigenicity tests with the membrane over agar associated to optimal sensibility plate assays were performed and showed that 96.77% of strains recovered from milk and 95.31% from food samples produced enterotoxins A, B, C, D or TSST-1. Reference strains S. epidermidis, Bacillus cereus, Listeria monocytogenes, Lactobacillus casei, Pseudomonas aeruginosa, S. aureus, Salmonella Typhimurium, Escherichia coli, Enterococcus faecalis and Bacteroides fragilis were used as indicator bacteria in the antagonistic assays, the first five being sensitive to antagonistic substances. Brain heart infusion agar, in pH values ranging from 5.0 to 7.0 in aerobic atmosphere showed to be the optimum condition for antagonistic activity as evaluated with the best producer strains against the most sensitive indicator bacterium, L. monocytogenes. Sensitivity to enzymes confirmed the proteinaceous nature of these substances. Neither bacteriophage activity nor fatty acids were detected and the antagonistic activity was not due to residual chloroform. Results did not establish a positive correlation between the bacteriocinogenic profile and toxigenicity in the tested S. aureus strains.

  3. Antimicrobial activity of green tea extract against isolates of methicillin-resistant Staphylococcus aureus and multi-drug resistant Pseudomonas aeruginosa

    Institute of Scientific and Technical Information of China (English)

    Maksum Radji; Rafael Adi Agustama; Berna Elya; Conny Riana Tjampakasari

    2013-01-01

    Objective: To evaluate antibacterial activity of the Indonesian water soluble green tea extract,Camellia sinensis, against clinical isolates of methicillin-resistant Staphylococcus aureus (S. aureus) (MRSA) and multi-drug resistant Pseudomonas aeruginosa (MDR-P. aeruginosa). Methods:Antimicrobial activity of green tea extract was determined by the disc diffusion method and the minimum inhibitory concentration (MIC) was determined by the twofold serial broth dilutions method. The tested bacteria using in this study were the standard strains and multi-drug resistant clinical isolates of S. aureus and P. aeruginosa, obtained from Laboratory of Clinical Microbiology, Faculty of Medicine, University of Indonesia. Results:The results showed that the inhibition zone diameter of green tea extracts for S. aureus ATCC 25923 and MRSA were (18.970±0.287) mm, and (19.130±0.250) mm respectively. While the inhibition zone diameter for P. aeruginosa ATCC 27853 and MDR-P. aeruginosa were (17.550±0.393) mm and (17.670±0.398) mm respectively. The MIC of green tea extracts against S. aureus ATCC 25923 and MRSA were 400 µg/mL and 400 µg/mL, respectively, whereas the MIC for P. aeruginosa ATCC 27853 and MDR-P. aeruginosa were 800 µg/mL, and 800 µg/mL, respectively. Conclusions: Camellia sinensis leaves extract could be useful in combating emerging drug-resistance caused by MRSA and P. aeruginosa.

  4. Identification of Secreted Exoproteome Fingerprints of Highly-Virulent and Non-Virulent Staphylococcus aureus Strains

    Science.gov (United States)

    Bonar, Emilia; Wojcik, Iwona; Jankowska, Urszula; Kedracka-Krok, Sylwia; Bukowski, Michal; Polakowska, Klaudia; Lis, Marcin W.; Kosecka-Strojek, Maja; Sabat, Artur J.; Dubin, Grzegorz; Friedrich, Alexander W.; Miedzobrodzki, Jacek; Dubin, Adam; Wladyka, Benedykt

    2016-01-01

    Staphylococcus aureus is a commensal inhabitant of skin and mucous membranes in nose vestibule but also an important opportunistic pathogen of humans and livestock. The extracellular proteome as a whole constitutes its major virulence determinant; however, the involvement of particular proteins is still relatively poorly understood. In this study, we compared the extracellular proteomes of poultry-derived S. aureus strains exhibiting a virulent (VIR) and non-virulent (NVIR) phenotype in a chicken embryo experimental infection model with the aim to identify proteomic signatures associated with the particular phenotypes. Despite significant heterogeneity within the analyzed proteomes, we identified alpha-haemolysin and bifunctional autolysin as indicators of virulence, whereas glutamylendopeptidase production was characteristic for non-virulent strains. Staphopain C (StpC) was identified in both the VIR and NVIR proteomes and the latter fact contradicted previous findings suggesting its involvement in virulence. By supplementing NVIR, StpC-negative strains with StpC, and comparing the virulence of parental and supplemented strains, we demonstrated that staphopain C alone does not affect staphylococcal virulence in a chicken embryo model. PMID:27242969

  5. Identification of secreted exoproteome fingerprints of highly-virulent and non-virulent Staphylococcus aureus strains.

    Directory of Open Access Journals (Sweden)

    Emilia eBonar

    2016-05-01

    Full Text Available Staphylococcus aureus is a commensal inhabitant of skin and mucous membranes in nose vestibule but also an important opportunistic pathogen of humans and livestock. The extracellular proteome as a whole constitutes its major virulence determinant; however, the involvement of particular proteins is still relatively poorly understood. In this study, we compared the extracellular proteomes of poultry-derived S. aureus strains exhibiting a virulent (VIR and non-virulent (NVIR phenotype in a chicken embryo experimental infection model with the aim to identify proteomic signatures associated with the particular phenotypes. Despite significant heterogeneity within the analyzed proteomes, we identified alpha-haemolysin and bifunctional autolysin as indicators of virulence, whereas glutamylendopeptidase production was characteristic for non-virulent strains.Staphopain C (StpC was identified in both the VIR and NVIR proteomes and the latter fact contradicted previous findings suggesting its involvement in virulence. By supplementing NVIR, StpC-negative strains with StpC and comparing the virulence of parental and supplemented strains, we demonstrated that staphopain C alone does not affect staphylococcal virulence in a chicken embryo model.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Staphylococcus aureus (MSSA) and MRSA (CC398) isolated from post-mortem samples from pigs.

    Science.gov (United States)

    van der Wolf, P J; Rothkamp, A; Junker, K; de Neeling, A J

    2012-07-06

    There are many reports on the occurrence of Livestock Associated Methicilline resistant Staphylococcus aureus (LA-MRSA, CC398) in healthy pigs. There are however, very few reports of LA-MRSA being associated with pathological lesions in pigs. With this study we try to find the answers to the questions: (1) how often is S. aureus found in post-mortem material from pigs, (2) how many of these isolates are methicillin resistant, (3) are these equally distributed over the years? Here we report the isolation of MRSA and of methicillin sensitive S. aureus (MSSA) from samples derived from post-mortem examinations at the Animal Health Service in The Netherlands in the period from 2003 through October 2008. The MSSA and MRSA described here were isolated from 159 pathological lesions and from 7 submissions of aborted foetuses derived from a total of 116 animals, representing 103 submissions coming from 92 different herds. This is approximately 0.5% of all pigs submitted for post mortem examination in those years. The proportion of pigs from which S. aureus (both MSSA and MRSA) was isolated from, did not increase over the years. MSSA (N=97) and LA-MRSA CC398 (N=18) were present mainly in (peri)arthritis in over 30% of all cases, but were also isolated from internal organs such as lung, brain, spleen, kidneys, heart, indicating septicaemia. Remarkably, one non-CC398 MRSA (ST1) was isolated in a joint and a kidney of one pig. This isolate was resistant to 5 out of 6 antimicrobials tested. There was no significant difference in the type of lesions in which LA-MRSA was found compared to MSSA. The number of antimicrobials these isolates were resistant to, increased rapidly after 2004. LA-MRSA was isolated for the first time in 2005 and then again in 2007 and 2008, suggesting that this is an emerging pathogen. However, due to changes in the panel of antimicrobials used to test S. aureus for antimicrobial susceptibility in 2005 and 2007, the possibility exists that we may have

  8. Antimicrobial Activity of Geranium Oil against Clinical Strains of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Monika Sienkiewicz

    2012-08-01

    Full Text Available The aim of this work was to investigate the antibacterial properties of geranium oil obtained from Pelargonium graveolens Ait. (family Geraniaceae, against one standard S. aureus strain ATCC 433000 and seventy clinical S. aureus strains. The agar dilution method was used for assessment of bacterial growth inhibition at various concentrations of geranium oil. Susceptibility testing of the clinical strains to antibiotics was carried out using the disk-diffusion and E-test methods. The results of our experiment showed that the oil from P. graveolens has strong activity against all of the clinical S. aureus isolates—including multidrug resistant strains, MRSA strains and MLSB-positive strains—exhibiting MIC values of 0.25–2.50 μL/mL.

  9. Persistent Staphylococcus aureus Isolates from Two Independent Cases of Bacteremia Display Increased Bacterial Fitness and Novel Immune Evasion Phenotypes

    OpenAIRE

    Richards, R L; Haigh, R. D.; Pascoe, B.; Sheppard, S.K.; Price, F.; Jenkins, D.; Rajakumar, K; Morrissey, J. A.

    2015-01-01

    Staphylococcus aureus bacteremia cases are complicated by bacterial persistence and treatment failure despite the confirmed in vitro susceptibility of the infecting strain to administered antibiotics. A high incidence of methicillin-resistant S. aureus (MRSA) bacteremia cases are classified as persistent and are associated with poorer patient outcomes. It is still unclear how S. aureus evades the host immune system and resists antibiotic treatment for the prolonged duration of a persistent in...

  10. Application of a Novel "Pan-Genome"-Based Strategy for Assigning RNAseq Transcript Reads to Staphylococcus aureus Strains.

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    Diego Chaves-Moreno

    Full Text Available Understanding the behaviour of opportunistic pathogens such as Staphylococcus aureus in their natural human niche holds great medical interest. With the development of sensitive molecular methods and deep-sequencing technology, it is now possible to robustly assess the global transcriptome of bacterial species in their human habitat. However, as the genomes of the colonizing strains are often not available compiling the pan-genome for the species of interest may provide an effective method to reliably and rapidly compile the transcriptome of a bacterial species. The pan-genome of S. aureus and its associated core and accessory components were compiled based on 25 genomes and comprises a total of 65,557 proteins clustering into 4,198 Orthologous Groups (OGs. The generated gene catalogue was used to assign RNAseq-derived sequence reads to S. aureus in a variety of in vitro and in vivo samples. In all cases, the number of reads that could be assigned to S. aureus was greater using the OG database than using a reference genome. Growth of two S. aureus strains in synthetic nasal medium confirmed that both strains experienced strong iron starvation. Traits such as purine metabolism appeared to be more affected in a typical nasal colonizer than in a strain representative of the S. aureus USA300 lineage. Mapping sequencing reads from a metatranscriptome generated from the human anterior nares allowed the identification of genes highly expressed by S. aureus in vivo. The OG database generated in this study represents a useful tool to obtain a snapshot of the functional attributes of S. aureus under different in vitro and in vivo conditions. The approach proved to be advantageous to assign sequencing reads to bacterial strains when RNAseq data is derived from samples where strain information and/or the corresponding genome/s are unavailable.

  11. PCR primers for the detection of staphylococcal enterotoxins K, L, and M and survey of staphylococcal enterotoxin types in Staphylococcus aureus isolates from food poisoning cases in Taiwan.

    Science.gov (United States)

    Chiang, Yu-Cheng; Chang, Li-Tung; Lin, Chia-Wei; Yang, Chi-Yea; Tsen, Hau-Yang

    2006-05-01

    Staphylococcal enterotoxins (SEs) are important causative agents in gastroenteritidis and food poisoning cases. They are serologically grouped into five major classical types, i.e., SEA, SEB, SEC, SED, and SEE. In addition, new SEs, such as SEG through SEM, have recently been identified and characterized. In an attempt to survey the distribution of classical and new SEs in organisms responsible for staphylococcal infections in Taiwan, we developed PCR primers for the genes that define the SEK, SEL, and SEM types. Bacterial strains other than sek, sel, and sem Staphylococcus aureus, including strains of other Staphylococcus species, did not generate any false-positive results when examined with these primers. The expression potential for the sek, sel, and sem types were also determined by reverse transcription-PCR. Together with the PCR primers specific for the classical SEs and other new SEs, including SEG, SEH, SEI, and SEJ, we surveyed the SE genes in S. aureus strains isolated from food poisoning cases. For 147 S. aureus isolates originating from food poisoning cases, 109 (74.1%) were positive for one or more SE genes. Of them, the major classical enterotoxin type was sea (28.6%), followed by seb (20.4%), sec (8.2%), and sed (2.0%). For the new SE types, sei (30.6%) was detected the most often, followed by sek (18.4%), sem (12.9%), and sel (8.2%). Also, 64 (43.5%) of the total bacterial strains had more than one enterotoxin gene.

  12. Possible healthcare-associated transmission as a cause of secondary infection and population structure of Staphylococcus aureus isolates from two wound treatment centres in Ghana

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    G. Kpeli

    2016-09-01

    Full Text Available We have previously shown that secondary infections of Buruli ulcer wounds were frequently caused by Staphylococcus aureus. To gain understanding into possible routes of secondary infection, we characterized S. aureus isolates from patient lesions and surrounding environments across two Ghanaian health centres. One hundred and one S. aureus isolates were isolated from wounds (n=93, 92.1% and the hospital environment (n=8, 7.9% and characterized by the spa gene, mecA and the Panton–Valentine leucocidin toxin followed by spa sequencing and whole genome sequencing of a subset of 49 isolates. Spa typing and sequencing of the spa gene from 91 isolates identified 29 different spa types with t355 (ST152, t186 (ST88, and t346 dominating. Although many distinct strains were isolated from both health centres, genotype clustering was identified within centres. In addition, we identified a cluster consisting of isolates from a healthcare worker, patients dressed that same day and forceps used for dressing, pointing to possible healthcare-associated transmission. These clusters were confirmed by phylogenomic analysis. Twenty-four (22.8% isolates were identified as methicillin-resistant S. aureus and lukFS genes encoding Panton–Valentine leucocidin were identified in 67 (63.8% of the isolates. Phenotype screening showed widespread resistance to tetracycline, erythromycin, rifampicin, amikacin and streptomycin. Genomics confirmed the widespread presence of antibiotic resistance genes to β-lactams, chloramphenicol, trimethoprim, quinolone, streptomycin and tetracycline. Our findings indicate that the healthcare environment probably contributes to the superinfection of Buruli ulcer wounds and calls for improved training in wound management and infection control techniques.

  13. Isolation of a Bacterium Strain Degraded Agar

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    One in 58 strains of bacteria isolated from the compost showed clear colonies after a few days of growth on the plates containing medium made of only agar and water.Water suspension contained only agar (2 and 8g·L -1 ) with two controls (normal saline,LB medium) was inoculated with the bacterium BR5-1 to see whether there was an increasement of the alive bacteria concentration after 48 h of the growth.The results showed that there was a significant rising of the alive bacteria concentration in the agar susp...

  14. Characterization of Methicillin-Resistant Staphylococcus aureus Isolated from Healthy Turkeys and Broilers Using DNA Microarrays

    Science.gov (United States)

    El-Adawy, Hosny; Ahmed, Marwa; Hotzel, Helmut; Monecke, Stefan; Schulz, Jochen; Hartung, Joerg; Ehricht, Ralf; Neubauer, Heinrich; Hafez, Hafez M.

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major human health problem and recently, domestic animals are described as carriers and possible reservoirs. Twenty seven S. aureus isolates from five turkey farms (n = 18) and two broiler farms (n = 9) were obtained by culturing of choana and skin swabs from apparently healthy birds, identified by Taqman-based real-time duplex nuc-mecA-PCR and characterized by spa typing as well as by a DNA microarray based assay which covered, amongst others, a considerable number of antibiotic resistance genes, species controls, and virulence markers. The antimicrobial susceptibility profiles were tested by agar diffusion assays and genotypically confirmed by the microarray. Five different spa types (3 in turkeys and 2 in broilers) were detected. The majority of MRSA isolates (24/27) belonged to clonal complex 398-MRSA-V. The most frequently occurring spa types were accordingly t011, t034, and t899. A single CC5-MRSA-III isolated from turkey and CC398-MRSA with an unidentified/truncated SCCmec element in turkey and broiler were additionally detected. The phenotypic antimicrobial resistance profiles of S. aureus isolated from both turkeys and broilers against 14 different antimicrobials showed that all isolates were resistant to ampicillin, cefoxitin, oxacillin, doxycycline, and tetracycline. Moreover, all S. aureus isolated from broilers were resistant to erythromycin and azithromycin. All isolates were susceptible to gentamicin, chloramphenicol, sulphonamides, and fusidic acid. The resistance rate against ciprofloxacin was 55.6% in broiler isolates and 42.1% in turkey isolates. All tetracycline resistant isolates possessed genes tetK/M. All erythromycin-resistant broiler isolates carried ermA. Only one broiler isolate (11.1%) carried genes ermA, ermB, and ermC, while 55.6% of turkey isolates possessed ermA and ermB genes. Neither PVL genes (lukF/S-PV), animal-associated leukocidin (lukM and luk-P83) nor the gene encoding

  15. Antimicrobial agent of susceptibilities and antiseptic resistance gene distribution among methicillin-resistant Staphylococcus aureus isolates from patients with impetigo and staphylococcal scalded skin syndrome.

    Science.gov (United States)

    Noguchi, Norihisa; Nakaminami, Hidemasa; Nishijima, Setsuko; Kurokawa, Ichiro; So, Hiromu; Sasatsu, Masanori

    2006-06-01

    The susceptibilities to antimicrobial agents of and distributions of antiseptic resistance genes in methicillin-resistant Staphylococcus aureus (MRSA) strains isolated between 1999 and 2004 in Japan were examined. The data of MRSA strains that are causative agents of impetigo and staphylococcal scalded skin syndrome (SSSS) were compared with those of MRSA strains isolated from patients with other diseases. The susceptibilities to antiseptic agents in MRSA isolates from patients with impetigo and SSSS were higher than those in MRSA isolates from patients with other diseases. The distribution of the qacA/B genes in MRSA strains isolated from patients with impetigo and SSSS (1.3%, 1/76) was remarkably lower than that in MRSA strains isolated from patients with other diseases (45.9%, 95/207). Epidemiologic typings of staphylococcal cassette chromosome mec (SCCmec) and pulsed-field gel electrophoresis (PFGE) showed that MRSA strains isolated from patients with impetigo and SSSS had type IV SCCmec (75/76), except for one strain, and 64.5% (49/76) of the strains had different PFGE types. In addition, the patterns of restriction digestion of all tested qacA/B plasmid in MRSA isolates having different PFGE types were identical. The results showed that a specific MRSA clone carrying qacA/B was not prevalent, but qacA/B was spread among health care-associated MRSA strains. Therefore, it was concluded that the lower distribution rate of qacA/B resulted in higher susceptibilities to cationic antiseptic agents in MRSA isolated from patients with impetigo and SSSS.

  16. Prevalence of clonal complexes and virulence genes among commensal and invasive Staphylococcus aureus isolates in Sweden.

    Directory of Open Access Journals (Sweden)

    Gunlög Rasmussen

    Full Text Available Staphylococcus aureus encodes a remarkable number of virulence factors which may contribute to its pathogenicity and ability to cause invasive disease. The main objective of this study was to evaluate the association between S. aureus invasiveness and bacterial genotype, in terms of the presence of virulence genes and affiliation to clonal complexes. Also, the significance of different virulence genes, mainly adhesins, for the development of infective endocarditis was investigated. DNA microarray technology was used to analyze 134 S. aureus isolates, all methicillin-susceptible, derived from three groups of clinically well-characterized patients: nasal carriers (n=46, bacteremia (n=55, and bacteremia with infective endocarditis (n=33. Invasive isolates were dominant in four of the major clonal complexes: 5, 8, 15, and 25. Of the 170 virulence genes examined, those encoding accessory gene regulator group II (agr II, capsule polysaccharide serotype 5 (cap5, and adhesins such as S. aureus surface protein G (sasG and fibronectin-binding protein B (fnbB were found to be associated with invasive disease. The same was shown for the leukocidin genes lukD/lukE, as well as the genes encoding serine protease A and B (splA/splB, staphylococcal complement inhibitor (scn and the staphylococcal exotoxin-like protein (setC or selX. In addition, there was a trend of higher prevalence of certain genes or gene clusters (sasG, agr II, cap5 among isolates causing infective endocarditis compared to other invasive isolates. In most cases, the presence of virulence genes was linked to clonal complex affiliation. In conclusion, certain S. aureus clonal lineages harboring specific sets of virulence genes seem to be more successful in causing invasive disease.

  17. Antibacterial Activity of Metabolites Products of Vibrio Alginolyticus Isolated from Sponge Haliclona sp. Against Staphylococcus Aureus

    Science.gov (United States)

    Nursyam, Happy

    2017-01-01

    The objective of this study was to investigate the antibacterial activity of primary and secondary metabolites from Vibrio alginoliticus isolated from sponge Haliclona sp. against Staphylococcus aureus. A descriptive method was used in this research. The antibacterial activity was analysed by paper disk method. The results showed that the primary metabolites produced by Vibrio alginoliticus that is in symbiosis with sponge Haliclona sp. were able to effectively inhibit Staphylococcus aureus growth with an inhibition zone diameter of 12.9 mm, while the secondary metabolites of 9.9 mm. Electrophoresis analysis of the primary metabolites showed that there were 11 protein bands which were not found in secondary metabolites. Protein bands with low molecular weights presumably had an inhibiting effect on the growth of Staphylococcus aureus.

  18. Genomic analysis of an emerging multiresistant Staphylococcus aureus strain rapidly spreading in cystic fibrosis patients revealed the presence of an antibiotic inducible bacteriophage

    Directory of Open Access Journals (Sweden)

    Boniface Stephanie

    2009-01-01

    Full Text Available Abstract Background Staphylococcus aureus is a major human pathogen responsible for a variety of nosocomial and community-acquired infections. Recent reports show that the prevalence of Methicillin-Resistant S. aureus (MRSA infections in cystic fibrosis (CF patients is increasing. In 2006 in Marseille, France, we have detected an atypical MRSA strain with a specific antibiotic susceptibility profile and a unique growth phenotype. Because of the clinical importance of the spread of such strain among CF patients we decided to sequence the genome of one representative isolate (strain CF-Marseille to compare this to the published genome sequences. We also conducted a retrospective epidemiological analysis on all S. aureus isolated from 2002 to 2007 in CF patients from our institution. Results CF-Marseille is multidrug resistant, has a hetero-Glycopeptide-Intermediate resistance S. aureus phenotype, grows on Cepacia agar with intense orange pigmentation and has a thickened cell wall. Phylogenetic analyses using Complete Genome Hybridization and Multi Locus VNTR Assay showed that CF-Marseille was closely related to strain Mu50, representing vancomycin-resistant S. aureus. Analysis of CF-Marseille shows a similar core genome to that of previously sequenced MRSA strains but with a different genomic organization due to the presence of specific mobile genetic elements i.e. a new SCCmec type IV mosaic cassette that has integrated the pUB110 plasmid, and a new phage closely related to phiETA3. Moreover this phage could be seen by electron microscopy when mobilized with several antibiotics commonly used in CF patients including, tobramycin, ciprofloxacin, cotrimoxazole, or imipenem. Phylogenetic analysis of phenotypically similar h-GISA in our study also suggests that CF patients are colonized by polyclonal populations of MRSA that represents an incredible reservoir for lateral gene transfer. Conclusion In conclusion, we demonstrated the emergence and

  19. Antibacterial effect of silver nanoparticles along with protein synthesis-inhibiting antibiotics on Staphylococcus aureus isolated from cattle mastitis

    Directory of Open Access Journals (Sweden)

    Malahat Ahmadi

    2014-01-01

    Full Text Available Introduction: Staphylococcus aureus is an opportunistic pathogen in dairy ruminants which is also found in healthy carriage and can be a major cause of mastitis. Various mastitis control programs have been used to combat the problem but have not always been efficient. In most countries, antibiotic resistance is extremely common. Silver nanoparticles have shown antimicrobial activity against S. aureus. In the present study the effect of silver nanoparticles on S. aureus isolated from cattle mastitis along with antibiotics of operative on protein bacterial synthesis investigated. Materials and methods: Three hundred eleven milk samples were collected from the cow farms. Each milk sample was cultured on mannitol salt agar and was incubated. A total of 72 isolates of S. aureus were isolated from the bovine mastitis milk samples. S. aureus DNA extracted by DNA purification kit according to the manufacturer protocol. 58 isolates were confirmed as S. aureus by biochemical tests as well as nuc gene detection. MIC and MBC determined for silver nanoparticles with antibiotics on 50 isolates. Results: The resistance of S. aureus isolates against erythromycin, gentamicin, streptomycin and doxycycline were 100, 22, 100 and 8%, respectively. 8 of all isolates were sensitive to 25 µg/ml concentration of silver nanoparticles. The 92% growth of the samples were inhibited at concentrations between 50-100 µg/ml. Discussion and conclusion: The present study suggests that antibiotics which can inhibit protein synthesis have significant synergistic effect along with silver nanoparticles.

  20. Isolation and Characterization of a New Arthrospira Strain

    OpenAIRE

    2008-01-01

    A filamentous microorganism, morphologically similar to the cyanobacterium Arthrospira, was isolated from Mangueira Lagoon in Brazil, from which Arthrospira has not previously been isolated. Random amplified polymorphic DNA (RAPD) comparison with the standard Arthrospira platensis strains LEB 52 and Paracas indicated that the organism isolated was an Arthrospira isolate, which we denominated strain LEB 18. The RAPD analysis showed conserved sequences which indicated that the three strains bel...

  1. Staphylococcus epidermidis ΔSortase A strain elicits protective immunity against Staphylococcus aureus infection.

    Science.gov (United States)

    Tan, Chao; Wang, Jun; Hu, Yifang; Wang, Peng; Zou, Lili

    2017-01-01

    Staphylococcus aureus and Staphylococcus epidermidis are two of the most significant opportunistic human pathogens, causing medical implant and nosocomial infections worldwide. These bacteria contain surface proteins that play crucial roles in multiple biological processes. It has become apparent that they have evolved a number of unique mechanisms by which they can immobilise proteins on their surface. Notably, a conserved cell membrane-anchored enzyme, sortase A (SrtA), can catalyse the covalent attachment of precursor bacterial cell wall-attached proteins to peptidoglycan. Considering its indispensable role in anchoring substrates to the cell wall and its effects on virulence, SrtA has attracted great attention. In this study, a 549-bp gene was cloned from a pathogenic S. epidermidis strain, YC-1, which shared high identity with srtA from other Staphylococcus spp. A mutant strain, YC-1ΔsrtA, was then constructed by allelic exchange mutagenesis. The direct survival rate assay suggested that YC-1ΔsrtA had a lower survival capacity in healthy mice blood compare with the wild-type strain, indicating that the deletion of srtA affects the virulence and infectious capacity of S. epidermidis YC-1. YC-1ΔsrtA was then administered via intraperitoneal injection and it provided a relative percent survival value of 72.7 % in mice against S. aureus TC-1 challenge. These findings demonstrate the possbility that YC-1ΔsrtA might be used as a live attenuated vaccine to produce cross-protection against S. aureus.

  2. Genetic Determination and Clonal Relationships of Staphylococcus aureus Isolated from Dairy Cows in Baturraden, Central Java, Indonesia

    Directory of Open Access Journals (Sweden)

    Fatkhanuddin Aziz

    2016-02-01

    Full Text Available Cases of mastitis in cows at Baturraden are leading to signifi cant and ongoing problems due to reducedproduction and lower milk quality. This study was designed to identify which of selected virulence determinantgenes of S. aureus are involved in the Baturraden infection, and to determine the clonal relationship amongthese isolates. Seventeen isolates were identifi ed as S. aureus based on their biochemical properties and speciesspecifi city for 23S rRNA and nuc genes. S. aureus isolates were genotypically characterized for the selectedvirulence determinants: coa, clfA, fnbA, fnbB, cap5, spa IgG and spa X- region genes. Clonal relationship analysisamong isolates was carried out using AFLP and results compared with previously confi rmed relationshipsbetween selected S. aureus isolated from other regions. The results show that eight isolates contain all thegenes, but six isolates lack fnbB and two isolates lack cap5 genes. AFLP analysis showed that all isolates of S.aureus originating from cows in Baturraden belong to one cluster. This study provides additional knowledgeabout S. aureus infection in Baturraden cows, including the number of virulence determinant genes that mayplay a role in pathogenicity.

  3. 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.

  4. Introduction of plasmid DNA into an ST398 livestock-associated methicillin-resistant Staphylococcus aureus strain

    Science.gov (United States)

    MRS926 is a livestock-associated methicillin-resistant Staphylococcus aureus (MRSA) strain of sequence type (ST) 398. In order to facilitate in vitro and in vivo studies of this strain, we sought to tag it with a fluorescent marker. We cloned a codon-optimized gene for TurboGFP into a shuttle vector...

  5. In vitro resistance to daptomycin of staphylococcus aureus and enterococcus spp. strains

    Directory of Open Access Journals (Sweden)

    Stan Irina

    2014-11-01

    Full Text Available Daptomycin is the first antibiotic in a new class of cyclic lipopeptides, active in vitro against Gram - positive cocci. The mechanism of action is a rapid depolarization of the bacterial membrane potential, loss of cytoplasmic contents, mainly K+ ions and inhibition of protein, DNA and RNA synthesis, followed by the bacterial cell death. There were investigated 112 strains of Gram-positive cocci recommended for daptomycin susceptibility testing. Since the main clinical indications of daptomycin are the severe skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus, vancomicin-resistant enterococci and penicillinresistant Streptococcus spp, we tested daptomycin activity only in these species.

  6. Leukocidin genes lukF-P83 and lukM are associated with taphylococcus aureus clonal complexes 151, 479 and 133 isolated from bovine udder infections in Thuringia, Germany

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    Schlotter Katharina

    2012-05-01

    Full Text Available Abstract Staphylococcus aureus is one of the most important causal agents of bovine mastitis. Population studies on bovine Staphylococcus aureus isolates have identified considerable genetic heterogeneity among strains causing mastitis. The aim of this study was to investigate the contribution of different clonal complexes and the occurrence of virulence factors and resistance determinants within bovine Staphylococcus aureus isolates. A total of 189 Staphylococcus aureus isolates obtained from milk samples of 34 dairy herds in the German Federal State of Thuringia were characterised by microarray technology. The isolates were assigned to eleven different clonal complexes with CC151, CC479 and CC133 being dominant (together 80.5%. The methicillin resistance gene mecA was found in four isolates (2.1%, which belonged to CC398. Enterotoxin genes could be detected in 79.3% of analysed Staphylococcus aureus and 19 isolates (10.1% harboured a distinct allele of the toxic shock syndrome toxin gene, tst-RF122. The most striking finding of the present study was that almost all except one isolate (151/152 belonging to CC151, CC479 and CC133 harboured the leukocidin genes lukF-P83 and lukM, whereas no further isolates from other lineages possessed these genes. The consistent occurrence of lukF-P83/lukM in the dominating clonal complexes suggests an essential role of this leukocidin in the etiology of bovine mastitis.

  7. Drug Resistance Reversal Potential of Isoliquiritigenin and Liquiritigenin Isolated from Glycyrrhiza glabra Against Methicillin-Resistant Staphylococcus aureus (MRSA).

    Science.gov (United States)

    Gaur, Rashmi; Gupta, Vivek Kumar; Singh, Pooja; Pal, Anirban; Darokar, Mahendra Padurang; Bhakuni, Rajendra Singh

    2016-10-01

    Isoliquiritigenin (ISL) and liquiritigenin (LTG) are structurally related flavonoids found in a variety of plants. Discovery of novel antimicrobial combinations for combating methicillin-resistant Staphylococcus aureus (MRSA) infections is of vital importance in the post-antibiotic era. The present study was taken to explore the in vitro and in vivo combination effect of LTG and ISL with β-lactam antibiotics (penicillin, ampicillin and oxacillin) against mec A-containing strains of MRSA. Minimum inhibitory concentration (MIC) of both LTG and ISL exhibited significant anti-MRSA activity (50-100 µg/mL) against clinical isolates of MRSA. The result of in vitro combination study showed that ISL significantly reduced MIC of β-lactam antibiotics up to 16-folds [∑ fractional inhibitory concentration (FIC) 0.312-0.5], while LTG reduced up to 8-folds (∑FIC 0.372-0.5). Time kill kinetics at graded MIC combinations (ISL/LTG + β-lactam) indicated 3.27-9.79-fold and 2.59-3.48-fold reduction in the growth of clinical isolates of S. aureus respectively. In S. aureus-infected Swiss albino mice model, combination of ISL with oxacillin significantly (p < 0.05, p < 0.01, p < 0.001) lowered the systemic microbial burden in blood, liver, kidney, lung and spleen tissues in comparison with ISL, oxacillin alone as well as untreated control. Considering its synergistic antibacterial effect, we suggest both ISL and LTG as promising compounds for the development of novel antistaphylococcal combinations. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Antibiotic activity of the extract of Punica granatum Linn. over bovine strains of Staphylococcus aureus Atividade antimicrobiana do extrato de Punica granatum Linn. em linhagens de Staphylococcus aureus de origem bovina

    Directory of Open Access Journals (Sweden)

    Maria A. R. Silva

    2008-06-01

    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.A medicina humana e veterinária tem falhado no tratamento de infecções em longo prazo causadas por Staphylococcus aureus associadas ao desenvolvimento de resistência a agentes antimicrobianos. A atividade antimicrobiana do extrato da casca do fruto de Punica granatum Linn. foi avaliada sobre 38 linhagens de S. aureus de origem bovina para a determinação da concentração inibitória mínima (CIM. Das 38 linhagens ensaiadas, 22 são resistentes à penicilina.(PRSA. O extrato de P. granatum apresentou potencial ação antimicrobiana sobre todas as linhagens ensaiadas formando halos de inibição variando de 10 a 36 mm de diâmetro. Os resultados deste estudo confirmam a eficácia do extrato de P. granatum como potencial agente antibacteriano sobre S. aureus e demonstram a importância de se avaliar novas substâncias com potencial antimicrobiano, o que pode contribuir para a

  9. Detection of ST772 Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus (Bengal Bay clone and ST22 S. aureus isolates with a genetic variant of elastin binding protein in Nepal

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    R.H. Pokhrel

    2016-05-01

    Full Text Available Genetic characteristics were analysed for recent clinical isolates of methicillin-resistant and -susceptible Staphylococcus aureus (MRSA and MSSA respectively in Kathmandu, Nepal. MRSA isolates harbouring Panton-Valentine leukocidin (PVL genes were classified into ST1, ST22 and ST88 with SCCmec-IV and ST772 with SCCmec-V (Bengal Bay clone, while PVL-positive MSSA into ST22, ST30 and ST772. ST22 isolates (PVL-positive MRSA and MSSA, PVL-negative MRSA possessed a variant of elastin binding protein gene (ebpS with an internal deletion of 180 bp, which was similar to that reported for ST121 S. aureus previously outside Nepal. Phylogenetic analysis indicated that the ebpS variant in ST22 might have occurred independently of ST121 strains. This is the first report of ST772 PVL-positive MRSA in Nepal and detection of the deletion variant of ebpS in ST22 S. aureus.

  10. Isolation and identification of Staphylococcus aureus from milk and milk products and their drug resistance patterns in Anand, Gujarat

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    M. N. Brahmbhatt

    2013-02-01

    Full Text Available Aim: The study was carried out with aim to isolate Staphylococcus aureus from milk and milk products (pedha and curd and determine antibiogram pattern of S. aureus isolates. Materials and Methods: During 9 months duration of study a total of 160 milk and milk product samples (pedha and curd were collected from different places in and around Anand city such as milk collection centre of Co-operative milk dairies, cattle farms, individual household, milk vendors and sweet shops. The samples were collected under aseptic precautions and were enriched in Peptone Water (PW followed by direct plating on selective media viz. Baird-Parker Agar. The presumptive S. aureus isolates were identified by biochemical tests. Antibiogram pattern of S. aureus to antimicrobial agents were evaluated by disk diffusion method. Results: Analysis of result revealed that out of total 160 samples of milk (100 and milk products i.e. curd (30 and pedha (30 resulted in the isolation of 10 isolates (6.25 % of S. aureus. In the present study S. aureus isolates were found variably resistant to the antibiotics tested. The S. aureus isolates showed highest sensitivity towards cephalothin (100.00 %, co-trimoxazole (100.00 %, cephalexin (100.00 % and methicillin (100.00 % followed by gentamicin (90.00 %, ciprofloxacin (80.00 %, oxacillin (70.00 %, streptomycin (60.00 % and ampicillin (60.00 %. The pattern clearly indicated that the overall high percent of S. aureus isolates were resistant to Penicillin-G (100.00 % followed by ampicillin (40.00 %, oxytetracycline and oxacillin (20.00 % and streptomycin and gentamicin (10.00 % Conclusions: Results clearly suggested a possibility of potential public health threat of S. aureus resulting from contamination of milk and milk products with pathogenic bacteria is mainly due to unhygienic processing, handling and unhygienic environment. [Vet World 2013; 6(1.000: 10-13

  11. Technological properties and probiotic potential of Lactobacillus fermentum strains isolated from West African fermented millet dough

    DEFF Research Database (Denmark)

    Owusu-Kwarteng, James; Tano-Debrah, Kwaku; Akabanda, Fortune;

    2015-01-01

    the isolation of indigenous strains from traditional fermented products to be used as functional starter cultures. These functional starter cultures possess inherent functional characteristics and can contribute to food quality and safety by offering one or more organoleptic, nutritional, technological...... activity was observed towards Listeria monocytogenes and Staphylococcus aureus but not E. coli and Salmonella enteritidis. Lactobacillus fermentum strains were generally susceptible to antibiotics except 6 strains which showed resistance towards streptomycin, gentamicin and kanamycin. CONCLUSION: In vitro...... determination of technological and probiotic properties have shown strain specific difference among L. fermentum strains isolated from fermented millet dough. Sixteen (16) L. fermentum strains have been shown to possess desirable technological and probiotic characteristics in vitro. These strains are therefore...

  12. Profile of antimicrobial susceptibility isolated microorganisms from hospitalized patients in PICU ward and detection of Methicillin-resistant Staphylococcus aureus and ESBL-producing bacteria by phenotypic methods

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    Shahla Abbas Poor

    2014-10-01

    Full Text Available Background: Hospital-acquired infections are a major challenge to patient. A range of gram-negative organisms are responsible for hospital-acquired infections, the Enterobacteriaceae family being the most commonly identified group overall. Infections by ESBL producers are associated with severe adverse clinical outcomes that have led to increased mortality, prolonged hospitalization, and rising medical costs. The aim of this study was to survey profile of antimicrobial susceptibility isolated microorganisms from hospitalized patients in PICU ward and detection of methicillin-resistant Staphylococcus aureus and ESBL-producing bacteria by phenotypic methods. Material and Methods: In this study participants were patients hospitalized in PICU part of Bahrami Hospital, Tehran, with attention to involved organ. For isolation of bacteria from patient’s samples, culture performed on different selective and differential media. After confirmation of bacteria by biochemical tests, susceptibility testing was performed by disc diffusion method. Phenotypic detection of MRSA strains was performed using cefoxcitin disc. ESBL producing strains were detected by ceftazidime (CAZ and ceftazidime/clavulanic acid (CAZ/CLA discs. Results: Among all isolated organisms from clinical samples, the most common isolated organisms were Escherichia coli (24 cases, Pseudomonas areoginosa (9 cases and Staphylococcus aureus (8 cases, respectively. Among eight MRSA isolated strains from different clinical samples, six strains (75% were MRSA. Among 52 isolated gram negative organisms, 5 strains (9/6% were ESBL. Conclusion: Standard interventions to prevent the transmission of antimicrobial resistance in health care facilities include hand hygiene, using barrier precautions in the care of colonized and infected patients, using dedicated instruments and equipment for these patients. The colonized or infected patients should be isolated in single rooms, multibed rooms or areas

  13. Phenotypic and genotypic correlates of daptomycin-resistant methicillin-susceptible Staphylococcus aureus clinical isolates.

    Science.gov (United States)

    Kang, Kyoung-Mi; Mishra, Nagendra N; Park, Kun Taek; Lee, Gi-Yong; Park, Yong Ho; Bayer, Arnold S; Yang, Soo-Jin

    2017-02-01

    Daptomycin (DAP) has potent activity in vitro and in vivo against both methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) strains. DAP-resistance (DAP-R) in S. aureus has been mainly observed in MRSA strains, and has been linked to single nucleotide polymorphisms (SNPs) within the mprF gene leading to altered cell membrane (CM) phospholipid (PL) profiles, enhanced positive surface charge, and changes in CM fluidity. The current study was designed to delineate whether these same genotypic and phenotypic perturbations are demonstrated in clinically-derived DAP-R MSSA strains. We used three isogenic DAP-susceptible (DAP-S)/DAP-R strainpairs and compared: (i) presence of mprF SNPs, (ii) temporal expression profiles of the two key determinants (mprF and dltABCD) of net positive surface charge, (iii) increased production of mprF-dependent lysinylated-phosphatidylglycerol (L-PG), (iv) positive surface charge assays, and (v) susceptibility to cationic host defense peptides (HDPs) of neutrophil and platelet origins. Similar to prior data in MRSA, DAP-R (vs DAP-S) MSSA strains exhibited hallmark hot-spot SNPs in mprF, enhanced and dysregulated expression of both mprF and dltA, L-PG overproduction, HDP resistance and enhanced positive surface charge profiles. However, in contrast to most DAP-R MRSA strains, there were no changes in CM fluidity seen. Thus, charge repulsion via mprF-and dlt-mediated enhancement of positive surface charge may be the main mechanism to explain DAP-R in MSSA strains.

  14. 158株金黄色葡萄球菌耐药性分析%Analysis of drug resisitance in 158 strains of Staphylococcus aureus

    Institute of Scientific and Technical Information of China (English)

    武超; 晏开力; 戴媛媛

    2012-01-01

    目的 了解住院患者感染的金黄色葡萄球菌(methicillin sensitive staphylococcus aureus,MSSA)对常用抗生素的耐药情况,以指导临床合理使用抗生素.方法 应用VITEK32微生物自动鉴定分析系统,采用K-B法对2009-03至2011-10临床各科室分离的158株MSSA进行药物敏感性试验,并对其药敏结果 进行统计分析.结果 158株MSSA中耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus,MRSA)96株,占60.76%,对青霉素G、氨苄西林100%耐药,对万古霉素100%敏感;对甲氧西林敏感MSSA,占39.24%,对青霉素G、氨苄西林耐药率分别为69.35%和67.74%,对利奈唑胺、喹努普汀/达福普汀和万古霉素100%敏感.结论 MSSA是临床感染的主要病原菌之一,分析MSSA耐药情况,可以指导临床合理选用抗生素.%Objective To study the resistance of clinically - isolated Staphylococcus aureus to antimicrobial agents so as to facilitate the rational use of antibiotics. Methods The pathogenic bacteria were evaluated by VITEK32. Drug susceptibility test was carried out by K - B method. The results of 158 strains of Staphylococcus aureus were analysed by WHONET. Results 96 strains of MR-SA were detected from 158 strains of Staphylococcus aureus, which accounted for 60.76% . All the MRSA was resistant to penicillin and ampicillin but was sensitive to vancomycin. The resistance rate of MSSA to penicillin and ampicillin was 69.35% and 67.74% , respectively, and all the MSSA was sensitive to linezolid, quinupristin/dalfopristin and vancomycin. Conclusions Staphylococcus aureus is one of the main pathogens of clinical infection. Analysis of drug resistance of Staphylococcus aureus can guide the clinical use of antibiotics.

  15. Study of antibiotic resistance of staph aureus and coagulase negative staphylococci isolated from patient samples

    Directory of Open Access Journals (Sweden)

    M Anvary

    2006-04-01

    Full Text Available Introduction: Drug resistant Staphylococci are the most important agents of nosocomial infections. In this survey, effect of different antibiotics on these bacteria and their drug resistance was investigated. Methods: The study included 500 strains of Staphylococci. Minimum Inhibitory Concentrations of all antibiotics was determined by the broth macro dilution technique and standard methods from the National Committee for Clinical Laboratory Standards. Result : Oxacillin resistance of S. aureus was 14.2% and that of coagulase-negative staphylococci was 53.4%. The activity of different antibiotics is presented in detail. Conclusion: Surveillance of strains resistant to methicillin is necessary.

  16. Occurrence of enterotoxin genes and macrorestriction analysis of Staphylococcus aureus isolated from bovine mastitis and bulk-tank milk samples in Italy. An epidemiological study

    Directory of Open Access Journals (Sweden)

    Roberto Rosmini

    2010-01-01

    Full Text Available The goal of the study was to genotypically compare S. aureus isolates from mastitis milk and raw milk to identify therelation between strains and to assess the enterotoxigenicity of the isolates. Eighty-three Staphylococcus aureus isolatesrecovered from cows and bulk tank milk of five farms in northern Italy were compared genotypically. The genes for theenterotoxins A, D, G and I, but not for B, C, E and H and the toxic shock syndrome toxin 1 (TSST-1, were detected byPCR amplification. Macrorestriction analysis with the restrictions enzyme SmaI revealed 14 pulsed-field gel electrophoresispatterns. These were in part different from each other only in a few fragments and thus displayed a closeclonal relation. The results of the present investigation showed that identical or closely related clones seemed to beresponsible for the cases of bovine mastitis in the farms investigated and partly responsible for contamination of bulktank milk.

  17. Ciprofloxacin susceptibility reduction of Salmonella strains isolated from outbreaks

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    Roberta B. Souza

    2010-06-01

    Full Text Available The antimicrobial susceptibility of 212 Salmonella strains isolated from patients and foods was evaluated and 45% were found to be resistant to nalidixic acid. Nalidixic acid resistant strains showed a higher minimal inhibitory concentration for ciprofloxacin than sensitive strains. During the study an increase of strains with reduced susceptibility to ciprofloxacin was also observed.

  18. Methicillin resistant Staphylococcus aureus isolated from meat raw in Cartagena, Colombia

    OpenAIRE

    Lersy López Gutierrez; Alfonso Bettin Martinez; Héctor Suárez Mahecha

    2017-01-01

    To determine the prevalence of Methicillin Resistant Staphylococcus aureus (MRSA) isolated in establishments that commercialize raw ground beef and pork chops in Cartagena- Colombia. 160 samples were analyzed through microbiological cultures in Baire Parcker agar, and it was determined the presence of mecA gen that codifies the methicillin resistance and the pvl that codifies the Panton- Valentine leukocidin toxin (PVL) by the multiplex PCR technique. The antibiotic susceptibility profile for...

  19. Antimicrobial susceptibility profiles of Staphylococcus aureus isolates classified according to their origin in a tertiary hospital in Korea.

    Science.gov (United States)

    Moon, Hee-Won; Kim, Hyun Jung; Hur, Mina; Yun, Yeo-Min

    2014-12-01

    We performed a comprehensive analysis on 3,594 Staphylococcus aureus isolates from routine culture during the last 4 years. The antimicrobial susceptibilities of the isolates were analyzed according to their origin and were compared based on the type of specimens. The proportion of methicillin-resistant Staphylococcus aureus (MRSA) in community-associated (CA), health care-associated, community onset (HACO), and health care-associated (HA) isolates were 33.0%, 54.3%, and 73.3%, respectively. The MRSA rate differed significantly between specimens, with the highest rate from urine in the CA and HACO isolates, whereas the highest rate from the respiratory tract was in the HA isolates. The monitoring of the MRSA rate in CA, HACO, and HA S aureus isolates would be valuable for surveillance. The elevated rates of MRSA in urinary specimens from CA and HCA isolates need to be addressed for infection control.

  20. Assessment of high and low enterotoxin A producing Staphylococcus aureus strains on pork sausage.

    Science.gov (United States)

    Zeaki, Nikoleta; Cao, Rong; Skandamis, Panagiotis N; Rådström, Peter; Schelin, Jenny

    2014-07-16

    Three Staphylococcus aureus strains representing different alleles of the Siphoviridae prophage-encoded enterotoxin A (SEA) gene, including two high-SEA-producing strains and one low-SEA-producing strain were studied to investigate sea expression and SEA formation on a frankfurter type of sausage. The effect of lactic acid, an antimicrobial compound used as a preservative in food, was also investigated on the same product. All three strains were grown on pork sausages at 15°C for 14days in the presence or absence of lactic acid (1 or 2% v/v). Growth, sea mRNA expression and SEA formation were regularly monitored and compared between non-treated and treated sausages. For all experiments performed, the extracellular SEA formation significantly differed between the high- and low-SEA-producing strains, although growth and viability were overall the same. For the low producer (Sa51), the accumulated amount of extracellular SEA formed after 14days was close to the detection limit (less than 1ng/g) in all conditions; while Sa21 and Sa17, the two high-producing strains, formed 250±25.37ng/g and 750±82.65ng/g in non-treated sausage and 150±75.75ng/g and 300±83.89ng/g when treated with 1% lactic acid, respectively, after 14days. Sausages treated with 2% lactic acid followed the same pattern as above, but with an extended lag phase to 4days and reduced levels of enterotoxin formed for all strains. The difference in the level of SEA between the two high-producing strains is most likely due to the different clonal lineages of the sea-encoded Siphoviridae phages where induction of the prophage potentially could be the reason for higher production of SEA in one of the lines. Furthermore, a prolonged expression of sea gene in the two high-producing strains was observed during the entire incubation period, while the sea expression was under the detection limit in the low-producing strain. This study indicates that the high-SEA-producing strains, especially the strains with the

  1. Nosocomial Infections: Multicenter surveillance of antimicrobial resistance profile of Staphylococcus aureus and Gram negative rods isolated from blood and other sterile body fluids in Iran

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    Bahman Poorabbas

    2015-11-01

    Full Text Available Background and Objective: Antibiotic resistance is increasing, especially in healthcare-associated infections causing significant public health concerns worldwide. National information is required to make appropriate policies, update list of essential drugs for treatment, and evaluate the effects of intervention strategies. A nationwide surveillance of antimicrobial resistant bacteria in nosocomial infections was established in Iran in 2008, so that the data obtained through the surveillance would enable us to construct a database.Materials and Methods: Seven major teaching hospitals in Shiraz, Tabriz, Sari, Mashhad, Sanandaj, Ahwaz and Isfahan participated in this study. A total of 858 strains isolated from blood and other sterile body fluids were tested. Identification at the species level was performed with conventional biochemical methods and the API system. Susceptibility tests were done using disk diffusion method. The methicillin-resistance in S. aureus (MRSA was determined by the oxacillin agar screen plate and respective MIC values were assessed using the E-test strips. The confirmatory disk diffusion methods were applied for phenotypic identification of extended-spectrum β- lactamase (ESBL production for E. coli and K. pneumoniae, according to CLSI guidelines.Results: Cultivation and re-identification of the strains yielded 858 isolates, consisting of 224 S. aureus, 148 Klebsiellaspp., 105 Serratia spp., 146 E. coli, 67 Acinetobacter spp., 38 Enterobacter spp., 95 Pseudomonas spp., 71 P.aeruginosa.35 Stenotrophomonas sp., and 8 other organisms. MRSA was detected in 37.5% of the isolates. No vancomycin-resistant or vancomycin-intermediate resistant S. aureus was detected. With the exception of Acinetobacter and Stenotrophomonas, 85% of the Gram-negative isolates were found to be susceptible in vitro to imipenem. Overall, about 61% of K. pneumoniae and 35% of E. coli isolates were ESBL producing.Conclusion: Multidrug resistant isolates

  2. Study of methicillin resistant S. aureus (MRSA isolates from high risk patients

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    Vidhani S

    2001-01-01

    Full Text Available MRSA is an important hospital pathogen, the incidence of which is increasing every year especially in high risk groups. The present study was performed in high risk patients admitted in burns and orthopaedic units of LN hospital to study the infection rate of MRSA from these units. The proportion of MRSA amongst S. aureus isolates was found to be 51.6% and these isolates were multidrug resistant. Phage typing of these isolates gave a typeability of 41.8% using the MRSA set of phages. Biotyping of these isolates could divide them into four groups. The study shows a high incidence of MRSA from burns and orthopaedic units with a high level of antibiotic resistance amongst these isolates.

  3. Association between the enterotoxin production and presence of Coa, Nuc genes among Staphylococcus aureus isolated from various sources, in Shiraz

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    Moghassem Hamidi, R; Hosseinzadeh, S; Shekarforoush, S. S.; Poormontaseri, M; Derakhshandeh, A

    2015-01-01

    The present study was aimed to identify the frequency of coagulase (Coa) and thermonuclease (Nuc) genes and Staphylococcal enterotoxin A (Sea) production among Staphylococcus aureus isolated from various sources in Shiraz. Moreover, the correlation between the Sea gene and coagulase and thermonuclease enzymes is also considered. A total of 100 S. aureus were isolated from various sources including 40 humans, 30 animals and 30 food samples by the routine biochemical tests. The frequency of Coa...

  4. 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.

  5. Genotypic and phenotypic detection of capsular polysaccharides in Staphylococcus aureus isolated from bovine intramammary infections in Argentina

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    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. Isolation of clinical strains of Pseudomonas aeruginosa harboring different plasmids.

    Science.gov (United States)

    Ranjbar, R; Owlia, P; Saderi, H; Bameri, Z; Izadi, M; Jonaidi, N; Morovvati, S

    2007-09-01

    Aim of this study was to investigate the presence of plasmids among the strains of P. aeruginosa isolated from clinically diagnosed cases in Tehran in 2006. A total of 38 strains of P. aeruginosa were isolated. With the exception of one isolate, all P. aeruginosa strains harbored at least one plasmid band. The electrophoretic analysis of plasmid DNAs showed different number of plasmid bands among the strains tested. The DNA band of 1.4 kbp was evident in 84.2% of the strains. Approximately 71 and 21% of the isolates harbored concomitantly two and three plasmids, respectively. Isolation of strains with diverse types of plasmids suggests the different cluster of P. aeruginosa might be disseminated during the current study period.

  7. The Distribution of 18 Enterotoxin and Enterotoxin-Like Genes in Staphylococcus aureus Strains from Different Sources in East China.

    Science.gov (United States)

    Cheng, Jinghua; Wang, Yan; Cao, Yongzhong; Yan, Wenguang; Niu, Xiaosai; Zhou, Liping; Chen, Jianhao; Sun, Ying; Li, Chenxi; Zhang, Xiaorong; Wu, Yantao

    2016-04-01

    The distribution of 18 staphylococcal enterotoxin (SE) or SE-like (SEl) genes in Staphylococcus aureus strains from different sources in east China was investigated. Among all 496 S. aureus strains, 291 strains carried one or more SE genes. The more frequently occurred genes were sea, seb, seg, selk, sell, selm, selo, and seq; the less frequent occurred genes were sec, selj, and ser. The classic SE genes and the enterotoxin gene cluster (egc) (seg, sei, selm, seln, selo, and/or selu) accounted for 25.67% and 61.68% of all detected genes, respectively. There were three gene clusters (egc, sea-sek-seq, and sed-sej-ser), of which the egc cluster was the important one that could generate novel complexes, and the sea-sek-seq cluster was a close relative to the hospital-acquired methicillin-resistant S. aureus. The SE gene distributions were different among strains of different sources and formed diverse toxin gene profiles. The human- and foodborne-origin strains harbored classic and novel SE and SEl genes, whereas animal-origin strains harbored egc and other novel SE and SEl genes mainly. The foodborne- and human-origin strains were the main dangerous factors of classic staphylococcal foodborne poisoning, whereas the strains (especially from animals) that carried egc and other novel genes mainly should be new potential dangerous factors for food safety.

  8. Genetic pathway in acquisition and loss of vancomycin resistance in a methicillin resistant Staphylococcus aureus (MRSA strain of clonal type USA300.

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    Susana Gardete

    2012-02-01

    Full Text Available An isolate of the methicillin-resistant Staphylococcus aureus (MRSA clone USA300 with reduced susceptibility to vancomycin (SG-R (i.e, vancomycin-intermediate S. aureus, VISA and its susceptible "parental" strain (SG-S were recovered from a patient at the end and at the beginning of an unsuccessful vancomycin therapy. The VISA phenotype was unstable in vitro generating a susceptible revertant strain (SG-rev. The availability of these 3 isogenic strains allowed us to explore genetic correlates of antibiotic resistance as it emerged in vivo. Compared to the susceptible isolate, both the VISA and revertant strains carried the same point mutations in yycH, vraG, yvqF and lspA genes and a substantial deletion within an intergenic region. The revertant strain carried a single additional frameshift mutation in vraS which is part of two component regulatory system VraSR. VISA isolate SG-R showed complex alterations in phenotype: decreased susceptibility to other antibiotics, slow autolysis, abnormal cell division and increased thickness of cell wall. There was also altered expression of 239 genes including down-regulation of major virulence determinants. All phenotypic properties and gene expression profile returned to parental levels in the revertant strain. Introduction of wild type yvqF on a multicopy plasmid into the VISA strain caused loss of resistance along with loss of all the associated phenotypic changes. Introduction of the wild type vraSR into the revertant strain caused recovery of VISA type resistance. The yvqF/vraSR operon seems to function as an on/off switch: mutation in yvqF in strain SG-R turns on the vraSR system, which leads to increase in vancomycin resistance and down-regulation of virulence determinants. Mutation in vraS in the revertant strain turns off this regulatory system accompanied by loss of resistance and normal expression of virulence genes. Down-regulation of virulence genes may provide VISA strains with a "stealth

  9. Investigation of the Antimicrobial Activity of Bacillus licheniformis Strains Isolated from Retail Powdered Infant Milk Formulae.

    Science.gov (United States)

    Alvarez-Ordóñez, Avelino; Begley, Máire; Clifford, Tanya; Deasy, Thérèse; Considine, Kiera; O'Connor, Paula; Ross, R Paul; Hill, Colin

    2014-03-01

    This study investigated the potential antimicrobial activity of ten Bacillus licheniformis strains isolated from retail infant milk formulae against a range of indicator (Lactococcus lactis, Lactobacillus bulgaricus and Listeria innocua) and clinically relevant (Listeria monocytogenes, Staphylococcus aureus, Streptococcus agalactiae, Salmonella Typhimurium and Escherichia coli) microorganisms. Deferred antagonism assays confirmed that all B. licheniformis isolates show antimicrobial activity against the Gram-positive target organisms. PCR and matrix-assisted laser desorption ionization time-of-flight mass spectrometry analyses indicated that four of the B. licheniformis isolates produce the bacteriocin lichenicidin. The remaining six isolates demonstrated a higher antimicrobial potency than lichenicidin-producing strains. Further analyses identified a peptide of ~1,422 Da as the most likely bioactive responsible for the antibacterial activity of these six isolates. N-terminal sequencing of the ~1,422 Da peptide from one strain identified it as ILPEITXIFHD. This peptide shows a high homology to the non-ribosomal peptides bacitracin and subpeptin, known to be produced by Bacillus spp. Subsequent PCR analyses demonstrated that the six B. licheniformis isolates may harbor the genetic machinery needed for the synthesis of a non-ribosomal peptide synthetase similar to those involved in production of subpeptin and bacitracin, which suggests that the ~1,422 Da peptide might be a variant of subpeptin and bacitracin.

  10. 同源性金黄色葡萄球菌生物被膜形成能力比较%Biofilm formation ability of homologous Staphylococcus aureus strains : a comparative study

    Institute of Scientific and Technical Information of China (English)

    孔晋亮; 张东伟; 陈一强; 闫萍; 蔡双启; 简丽娟

    2013-01-01

    目的 比较临床分离同源性金黄色葡萄球菌(SAU)的黏附及生物被膜(BF)形成能力差异.方法 刚果红平板法定性能形成BF的菌株;建立SAU的BF体外静置模型,分别于建模第1、3、7天,采用结晶紫染色方法,比较临床分离同源性SAU的黏附及BF形成能力差异.结果 临床分离10株同源性SAU中,刚果红平板法定性可全部形成BF;SAU 17546的黏附及形成早期BF能力最强(P<0.001),而SAU 17422最弱(P<0.001);形成成熟BF能力,仍以SAU 17546最强(P<0.001),但SAU 17642与17546比较,两者极近似(P =0.495);SAU 17422形成BF能力最弱,但是与17431、18541-2、18558、18565、18719等菌株差异无统计学意义.结论 刚果红平板法可定性SAU形成BF菌株,同源性SAU黏附及形成BF的能力存在差异.%OBJECTIVE To compare the adhesion and the abilities of biofilm formation of the homologous clinical isolates of Staphylococcus aureus. METHODS Congo red plate method was used to detect strains The in vitro biofilm model of S. aureus was established, and the crystal violet staining biofilm semi-quantitative method was employed to compare the adhesion and biofilm formation abilities of the homologous S. aureus. RESULTS Totally 10 strains of homologous S. aureus were biofilm formation-positive, which were isolated from the clinic. The ability of adhesion and early biofilm formation of S. aureus 17546 was the strongest (P<0. 001), but S. aureus 17422's was the weakest (P<0. 001). As for the formation ability of the mature biofilm, S. aureus 17546 was the most powerful (P<0. 001), S. aureus 17642 was extremely similar to strain 17546(P=0. 495). the biofilm formation ability of S. aureus 17422 was the weakest, but as compared with S. aureus 17431, S. aureus 18541-2, S. aureus 18558, S. aureus 18565 and S. aureus 18719, the difference was not statistically significant. CONCLUSION Congo red plate method can detect the S. aureus strains of BF formation. All the homologous S

  11. Molecular typing of toxic shock syndrome toxin-1- and Enterotoxin A-producing methicillin-sensitive Staphylococcus aureus isolates from an outbreak in a neonatal intensive care unit.

    Science.gov (United States)

    Layer, Franziska; Sanchini, Andrea; Strommenger, Birgit; Cuny, Christiane; Breier, Ann-Christin; Proquitté, Hans; Bührer, Christoph; Schenkel, Karl; Bätzing-Feigenbaum, Jörg; Greutelaers, Benedikt; Nübel, Ulrich; Gastmeier, Petra; Eckmanns, Tim; Werner, Guido

    2015-10-01

    Outbreaks of Staphylococcus aureus are common in neonatal intensive care units (NICUs). Usually they are documented for methicillin-resistant strains, while reports involving methicillin-susceptible S. aureus (MSSA) strains are rare. In this study we report the epidemiological and molecular investigation of an MSSA outbreak in a NICU among preterm neonates. Infection control measures and interventions were commissioned by the Local Public Health Authority and supported by the Robert Koch Institute. To support epidemiological investigations molecular typing was done by spa-typing and Multilocus sequence typing; the relatedness of collected isolates was further elucidated by DNA SmaI-macrorestriction, microarray analysis and bacterial whole genome sequencing. A total of 213 neonates, 123 healthcare workers and 205 neonate parents were analyzed in the period November 2011 to November 2012. The outbreak strain was characterized as a MSSA spa-type t021, able to produce toxic shock syndrome toxin-1 and Enterotoxin A. We identified seventeen neonates (of which two died from toxic shock syndrome), four healthcare workers and three parents putatively involved in the outbreak. Whole-genome sequencing permitted to exclude unrelated cases from the outbreak and to discuss the role of healthcare workers as a reservoir of S. aureus on the NICU. Genome comparisons also indicated the presence of the respective clone on the ward months before the first colonized/infected neonates were detected.

  12. Towards the Understanding of Resistance Mechanisms in Clinically Isolated Trimethoprim-resistant, Methicillin-resistant Staphylococcus aureus Dihydrofolate Reductase

    Energy Technology Data Exchange (ETDEWEB)

    Frey, K.; Lombardo, M; Wright, D; Anderson, A

    2010-01-01

    Resistance to therapeutics such as trimethoprim-sulfamethoxazole has become an increasing problem in strains of methicillin-resistant Staphylococcus aureus (MRSA). Clinically isolated trimethoprim-resistant strains reveal a double mutation, H30N/F98Y, in dihydrofolate reductase (DHFR). In order to develop novel and effective therapeutics against these resistant strains, we evaluated a series of propargyl-linked antifolate lead compounds for inhibition of the mutant enzyme. For the propargyl-linked antifolates, the F98Y mutation generates minimal (between 1.2- and 6-fold) losses of affinity and the H30N mutation generates greater losses (between 2.4- and 48-fold). Conversely, trimethoprim affinity is largely diminished by the F98Y mutation (36-fold) and is not affected by the H30N mutation. In order to elucidate a mechanism of resistance, we determined a crystal structure of a complex of this double mutant with a lead propargyl-linked antifolate. This structure suggests a resistance mechanism consistent both for the propargyl-linked class of antifolates and for trimethoprim that is based on the loss of a conserved water-mediated hydrogen bond.

  13. Characterization of methicillin-resistant Staphylococcus aureus isolated at Tripoli Medical Center, Libya, between 2008 and 2014.

    Science.gov (United States)

    BenDarif, Elloulu; Khalil, Asma; Rayes, Abdunnabi; Bennour, Emad; Dhawi, Abdulgader; Lowe, John J; Gibbs, Shawn; Goering, Richard V

    2016-12-01

    Bacterial pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) represent a well-known public health problem affecting both healthcare-associated and community populations. Past studies have clearly shown the value of characterizing problem organisms including MRSA through the use of molecular techniques (i.e. strain typing), with the aim of informing local, regional and national efforts in epidemiological analysis and infection control. The country of Libya represents a challenge for such analysis due to limited historical infectious disease information and major political unrest culminating in the Libyan Civil War (Libyan Revolution) in 2011. A MRSA study population of 202 isolates, cultured from patients in Tripoli Medical Center through this historical period (2008-2014), was characterized by both phenotypic and molecular methods. The results revealed a diversification of epidemic MRSA strains over time with generally increasing resistance to fluoroquinolone antibiotics. The study identified prevalent MRSA in comparison to known global epidemic types, providing unique insight into the change of strains and/or characteristics over time especially with reference to the potential influence of the political revolution (i.e. pre- and post-2011).

  14. Staphylococcal enterotoxin A gene-carrying Staphylococcus aureus isolated from foods and its control by crude alkaloid from papaya leaves.

    Science.gov (United States)

    Handayani, Lita; Faridah, Didah Nur; Kusumaningrum, Harsi D

    2014-11-01

    Staphylococcus aureus is a known pathogen causing intoxication by producing enterotoxins in food. Staphylococcal enterotoxin A is one of the enterotoxins commonly implicated in staphylococcal food poisoning. The ability of crude alkaloid extract from papaya leaves to inhibit the growth of S. aureus and staphylococcal enterotoxin A synthesis was investigated. Staphylococcal enterotoxin A gene-carrying S. aureus was isolated from raw milk and ready-to-eat foods. Crude alkaloid was extracted from ground, dried papaya leaves using ultrasonic-assisted extraction, and a MIC of the alkaloid was determined by the broth macrodilution method. Furthermore, S. aureus isolate was exposed to the crude alkaloid extract at one- and twofold MIC, and the expression of sea was subsequently analyzed using a quantitative reverse transcription real-time PCR. Ten isolates of S. aureus were obtained, and nine of those isolates were sea carriers. The yield of crude alkaloid extract was 0.48 to 1.82% per dry weight of papaya leaves. A MIC of crude alkaloid to S. aureus was 0.25 mg/ml. After exposure to the alkaloid at 0.25 and 0.5 mg/ml for 2 h, a significant increase in cycle threshold values of sea was observed. The sea was expressed 29 and 41 times less when S. aureus was exposed to crude alkaloid at one- and twofold MIC, respectively. This study revealed that crude alkaloid of papaya leaves could control staphylococcal enterotoxin A gene-carrying S. aureus by suppressing the expression of sea, in addition to the ability to inhibit the growth of S. aureus. The expression of sea was successfully quantified.

  15. Antibacterial Activity of Cold Atmospheric Pressure Argon Plasma against 78 Genetically Different (mecA, luk-P, agr or Capsular Polysaccharide Type) Staphylococcus aureus Strains.

    Science.gov (United States)

    Matthes, Rutger; Lührman, Anne; Holtfreter, Silva; Kolata, Julia; Radke, Dörte; Hübner, Nils-Olaf; Assadian, Ojan; Kramer, Axel

    2016-01-01

    Previous studies on the antimicrobial activity of cold atmospheric pressure argon plasma showed varying effects against mecA+ or mecA-Staphylococcus aureus strains. This observation may have important clinical and epidemiological implications. Here, the antibacterial activity of argon plasma was investigated against 78 genetically different S. aureus strains, stratified by mecA, luk-P, agr1-4, or the cell wall capsule polysaccharide types 5 and 8. kINPen09® served as the plasma source for all experiments. On agar plates, mecA+luk-P-S. aureus strains showed a decreased susceptibility against plasma compared to other S. aureus strains. This study underlines the high complexity of microbial defence against antimicrobial treatment and confirms a previously reported strain-dependent susceptibility of S. aureus to plasma treatment.

  16. Genetic diversity and virulence potential of Staphylococcus aureus isolates from raw and processed food commodities in Shanghai.

    Science.gov (United States)

    Song, Minghui; Bai, Yalong; Xu, Jie; Carter, Michelle Qiu; Shi, Chunlei; Shi, Xianming

    2015-02-16

    The risk of zoonotic transmission to humans highlights the need to understand the molecular ecology of Staphylococcus aureus in foods. In this study, 142 S. aureus isolates obtained from various raw and processed foods from Shanghai, China were characterized to determine their genetic diversity and virulence gene content. A total of 16 clonal complexes (CCs), 34 staphylococcal protein A (spa) types, and 6 accessory gene regulator (agr) allelic groups were identified and analyzed among the 142 S. aureus isolates. Among these, the genotype CC188-t189-agr Ι was the most prevalent, constituting 28.2% of all isolates. The presence of virulence genes encoding 20 staphylococcal enterotoxins (se), toxic shock syndrome toxin (tsst1), exfoliative toxins (eta, etb, and etd), Panton-Valentine leukocidin (lukS-PV and lukF-PV), as well as methicillin resistance gene (mecA), was determined by PCR. Of these S. aureus isolates, 72.5% harbored toxin genes, in which the most frequent toxin gene was sep (43.7%), followed by sej (26.1%) and pvl (21.1%). In contrast, see, ses, set, tsst1, etb, and etd were not found in any of the isolates tested. Eight S. aureus isolates (5.6%, 8/142), seven from raw milk and one from frozen food, were mecA positive and resistant to oxacillin, thus were MRSA. The 142 S. aureus isolates displayed 52 different toxin gene profiles. Although no direct association was found between toxin gene profile and the S. aureus genotype, the isolates belonging to CC5, CC9, CC20, CC50, and CC72 clonal lineages in general carried more toxin genes (>5) compared with the isolates in other CCs. It was also revealed that raw milk and raw meat were the major sources of isolates containing multiple toxin genes. S. aureus isolates from food that were genetically highly related, displayed diverse toxin gene profiles, implying the significant role of horizontal gene transfer in the emergence of highly toxigenic S. aureus isolates.

  17. Clinical outcomes of osteomyelitis patients infected with methicillin-resistant Staphylococcus aureus USA-300 strains.

    Science.gov (United States)

    Peyrani, P; Allen, M; Seligson, D; Roberts, C; Chen, A; Haque, N; Zervos, M; Wiemken, T; Harting, J; Christensen, D; Ramirez, R

    2012-03-01

    Methicillin-resistant Staphylococcus aureus (MRSA) USA-300 strains have emerged as an important cause of community-acquired infections. These strains have been recognized as an etiology of osteomyelitis but data on their incidence and outcomes are limited. We retrospectively studied the incidence and clinical outcomes of MRSA USA-300 osteomyelitis in patients at the University of Louisville Hospital and the Henry Ford Health System between January 2007 and March 2008. Pulsed-field gel electrophoresis was used to determine USA type. Clinical outcomes were defined as management success versus failure at 12 months. Chi-square tests, Fisher exact tests, and Mann-Whitney tests were used to compare patient characteristics on the basis of clinical outcomes and USA type. Of the 50 patients with MRSA osteomyelitis, 27 (54%) had the USA-300 strain. Clinical failure was identified in 22% (6/27) of the patients with MRSA USA-300 and in 30% (7/23) of the patients with MRSA non-USA-300 osteomyelitis (P = .509). Our results showed that MRSA USA-300 is a significant etiology of MRSA osteomyelitis. With current surgical and medical management, outcomes of patients with MRSA USA-300 osteomyelitis are similar to those of patients with MRSA non-USA-300 osteomyelitis.

  18. Isolation And Partial Characterization Of Bacteria Activity Associated With Gorgonian Euplexaura sp. Against Methicillin-Resistant Staphylococcus aureus (MRSA)

    Science.gov (United States)

    Kristiana, R.; Ayuningrum, D.; Asagabaldan, M. A.; Nuryadi, H.; Sabdono, A.; Radjasa, O. K.; Trianto, A.

    2017-02-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infection has emerged in around the world and has been resistance to ciprofloxacin, erythromycin, clindamycin. The aims of this study were to isolate, to investigate and to characterize bacterial symbionts gorgonian having activity against MRSA. Euplexaura sp. was collected from Panjang Island, Jepara, Indonesia by snorkling 2-5 m in depth. Bacterias were isolated by using spesific media with dilution method. Bacterias were conducted by using the streak method. Antibacterial activity was investigated by overlay method. The potent bacteria was identified by using molecular identification (DNA extraction, electrophoresis, PCR and phylogenetic analysis using 16S rDNA genes with actinobacteria-spesific primers) and bio-chemical test (among 5 isolated bacteria from gorgonian showed activity against MRSA). The strain PG-344 was the best candidat that has an inhibition zone against MRSA. The result of sequencing bacteria is 100% closely related with Virgibacillus salarius. This becomes a potential new bioactive compounds to against MRSA that can be a new drug discovery.

  19. 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.

  20. Technological Aptitude and Applications of Leuconostoc mesenteroides Bioactive Strains Isolated from Algerian Raw Camel Milk

    Directory of Open Access Journals (Sweden)

    Zineb Benmechernene

    2013-01-01

    Full Text Available Two strains (B7 and Z8 of the Leuconostoc mesenteroides subspecies mesenteroides that were isolated from Algerian camel milk from an initial pool of 13 strains and demonstrated a high ability to inhibit the growth of Listeria spp. were selected and characterised at the phenotypic and genotypic levels. Probiotic profiling and inhibition spectra against food borne pathogens in mixed cultures were also investigated. The bacteriocin produced by L. mesenteroides strain B7 was identified as leucocin B by specific PCR. In vitro studies demonstrated that both Leuconostoc mesenteroides strains exhibited a marked probiotic profile, showing high survival at low pH (2-3 and 4 in the presence of 0.5%, 1%, and 2% of bile salts and at pH 3 in the presence of 3 mg/mL pepsin. Susceptibility testing against antimicrobial agents was also performed for both strains. When tested in a mixed culture with Listeria innocua, Listeria ivanovii, or Staphylococcus aureus, strain B7 reduced the numbers of these species by 1.87, 1.78, and 1.38 log units, respectively. Consequently, these two strains were found to possess good probiotic properties in vitro and a high capacity for Listeria spp. inhibition in mixed cultures. Therefore, these strains have a favourable technological aptitude and a potential application as novel probiotic starters.

  1. Bioactivity characterization of Lactobacillus strains isolated from dairy products

    OpenAIRE

    Haghshenas, Babak; Nami, Yousef; Haghshenas, Minoo; Abdullah, Norhafizah; Rosli, Rozita; Radiah, Dayang; Yari Khosroushahi, Ahmad

    2015-01-01

    This study aimed to find candidate strains of Lactobacillus isolated from sheep dairy products (yogurt and ewe colostrum) with probiotic and anticancer activity. A total of 100 samples were randomly collected from yogurt and colostrum and 125 lactic acid bacteria were isolated. Of these, 17 Lactobacillus strains belonging to five species (L. delbrueckii, L. plantarum, L. rhamnosus, L. paracasei, and L. casei) were identified. L. plantarum 17C and 13C, which isolated from colostrums, demonstra...

  2. Measurement of antimicrobial activity of isolated bacteria from the Caspian sea and molecular identification of strains with antimicrobial effect

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    Sajad Harounabadi

    2015-12-01

    Full Text Available Introduction: Easy access and wide use of antimicrobial compounds led to the emergence of resistance among microorganisms. Therefore, screening and identifying antimicrobial compound with high effect of microorganisms in different environments is necessary and vital . Using microorganisms for biological aims change them to an important tool to control pathogens. Streptomyces griseus is one of them. The aim of this study is isolation of marine bacteria with antimicrobial effect against gram positive and negative bacteria. Finally, molecular identification of strains with antimicrobial activity. Materials and methods: In this study, 162 strains were isolated from the Caspian Sea .The strains were cultured on special medium and finally antimicrobial activity on references strains as measured. Among them four strains with remarkable antimicrobial activity were identified and selected. The strains were subjected to 16S rDNA PCR sequencing. The strains were submitted to NCBI as new Streptomyces griseus strains. Results: Among 162 strains, 4 strains had the most antimicrobial activity. The result showed, the strains were the most effective on Bacillus subtilis and Staphylococcus aureus (Gram positive bacteria and the least effect were observed on Escherichia coli and Pseudomonas aeruginosa (Gram negative bacteria. After sequencing, the strains were classified to sterptomyces griseus genu. Discussion and conclusion: In this study, 4 strains with antimicrobial activity were identified. According to the strength of these bacteria for controlling pathogenic bacteria resistant to antibiotic, we can have more pure microorganisms in optimized and controlled conditions for using in pharmaceutical industries and also for the treatment of dangerous pathogenic bacteria.

  3. Antimicrobial susceptibility patterns and characterization of clinical isolates of Staphylococcus aureus in KwaZulu-Natal province, South Africa

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    Lin Johnson

    2006-07-01

    Full Text Available Abstract Background Antimicrobial resistance of Staphylococcus aureus especially methicillin-resistant S. aureus (MRSA continues to be a problem for clinicians worldwide. However, few data on the antibiotic susceptibility patterns of S. aureus isolates in South Africa have been reported and the prevalence of MRSA in the KwaZulu-Natal (KZN province is unknown. In addition, information on the characterization of S. aureus in this province is unavailable. This study investigated the susceptibility pattern of 227 S. aureus isolates from the KZN province, South Africa. In addition, characterization of methicillin-sensitive S. aureus (MSSA and MRSA are reported in this survey. Methods The in-vitro activities of 20 antibiotics against 227 consecutive non-duplicate S. aureus isolates from clinical samples in KZN province, South Africa were determined by the disk-diffusion technique. Isolates resistant to oxacillin and mupirocin were confirmed by PCR detection of the mecA and mup genes respectively. PCR-RFLP of the coagulase gene was employed in the characterization of MSSA and MRSA. Results All the isolates were susceptible to vancomycin, teicoplanin and fusidic acid, and 26.9% of isolates studied were confirmed as MRSA. More than 80% of MRSA were resistant to at least four classes of antibiotics and isolates grouped in antibiotype 8 appears to be widespread in the province. The MSSA were also susceptible to streptomycin, neomycin and minocycline, while less than 1% was resistant to chloramphenicol, ciprofloxacin, rifampicin and mupirocin. The inducible MLSB phenotype was detected in 10.8% of MSSA and 82% of MRSA respectively, and one MSSA and one MRSA exhibited high-level resistance to mupirocin. There was good correlation between antibiotyping and PCR-RFLP of the coagulase gene in the characterization of MRSA in antibiotypes 1, 5 and 12. Conclusion In view of the high resistance rates of MRSA to gentamicin, erythromycin, clindamycin, rifampicin and

  4. Frequency of genes encoding erythromycin ribosomal methylases among Staphylococcus aureus clinical isolates with different D-phenotypes in Tehran, Iran

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    Sareh Sadat Hosseini

    2016-10-01

    Full Text Available Background and Objectives: Macrolide, lincosamide and streptogramin type B (MLSB antibiotics are important in the treatment of Staphylococcus aureus infections and existence of isolates with ability to resist against MLSB antibiotics is worrisome.Materials and Methods: In this cross sectional study, 101 S. aureus isolates were collected from patients of five selected hospitals in Tehran over a period of five months. Disk diffusion tests and differentiation between constitutive and inducible resistances were carried out by D-test. The presence of mecA, msrA, ermA and ermC genes were detected using PCR or multiplex PCR.Results: Out of 101 S. aureus isolates, 58 (57.4% were methicillin resistant and 57 (56.4% expressed resistance to erythromycin. The prevalence of constitutive MLSB (cMLSB, inducible MLSB (iMLSB and MS (Negative phenotype in all erythromycin resistant isolates were 71.9, 26.3 and 1.7%, respectively. Out of all the erythromycin resistant isolates, 57.8% harbored both ermA and ermC genes which possessed constitutive resistance. 8.7% of the isolates contained ermA gene alone which possessed inducible resistance with D phenotype and 5.2% of isolates just contained ermC gene which had inducible resistance with D+ phenotype. msrA gene was detected in 3.5% of the erythromycin resistant S. aureus isolates with constitutive resistance. None of the genes were detected among MS phenotypes.Conclusion: In this study, most of S. aureus isolates carried both ermA and ermC genes and there was a significant relationship (P value ≤ 0.05 between different resistance phenotypes and erm genes.Keywords: Staphylococcus aureus, D-test, Erm A, ErmC, MsrA

  5. Antibiotic resistance of Staphylococcus aureus isolated from enteral diets in a public hospital of Minas Gerais Resistência a antibióticos de Staphylococcus aureus isolados de dietas enterais em um hospital público de Minas Gerais

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    Nélio José de Andrade

    2007-10-01

    Full Text Available Enteral diets constitute an excellent means for microbial growth due to its composition rich in nutrients and its time of exposure to room temperature during application. Among the pathogenic bacteria there is the Staphylococcus aureus that is an opportunist microorganism found in the humans’ mucous membrane (buccal, nasal and oral. Samples of enteral diet after application as well as of the environment used for the preparation of the diets, were collected in a public hospital in Minas Gerais and analyzed for the presence of S. aureus. The contamination by S. aureus was evidenced in 83% of the enteral diet samples. As for the environment, the values found were in conformity with APHA recommendation. The isolated strains were submitted to the evaluation of the resistance to different antibiotics. Resistance was observed for tetracycline (100%, erythromycin (90,9%, chloramphenicol (59,1%, estreptomycin (22,72%, penicillin 18,8%, vancomycin (13,63%, ampicillin (13,63%, amoxilin (9,09% and gentamicin (4,54%. Due to the versatility in the resistance development to several antibiotics the S. aureus survives in hospital environments and can be diffused among patients. Dietas enterais constituem um excelente meio para crescimento microbiano, devido à sua composição rica em nutrientes e ao tempo de exposição à temperatura ambiente durante a administração. Dentre as bactérias patogênicas que podem ser encontradas nessas dietas, cita-se o Staphylococcus aureus, microrganismo oportunista encontrado na microbiota da membrana mucosa (bucal, nasal e oral em seres humanos. Amostras de dieta enteral pós-administração e do ambiente utilizado para o seu preparo foram coletadas em um hospital público e analisadas quanto à presença de S. aureus. A contaminação foi evidenciada em 83% das amostras de dietas enterais, e, quanto ao ambiente, os valores encontrados se apresentam de acordo com a recomendação da APHA. As cepas isoladas foram

  6. Radiation resistance of lactobacilli isolated from radurized meat relative to growth and environment. [Lactobacillus sake; Lactobacillus curvatus; Lactobacillus farciminis; Staphylococcus aureus; Salmonella typimurium

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    Hastings, J.W.; Holzapfel, W.H.; Niemand, J.G.

    1986-10-01

    Of 113 lactobacilli isolated from radurized (5 kGy) minced meat, 7 Lactobacillus sake strains, 1 L. curvatus strain, and 1 L. farciminis strain were used for radiation resistance studies in a semisynthetic substrate (i.e., modified MRS broth). Five reference Lactobacillus spp. one Staphylococcus aureus strain, and one Salmonella typhimurium strain were used for comparative purposes. All L. sake isolates exhibited the phenomenon of being more resistant to gamma-irradiation in the exponential (log) phase than in the stationary phase of their growth cycles by a factor of 28%. Four reference strains also exhibited this phenomenon, with L. sake (DSM 20017) showing a 68% increase in resistance in the log phase over the stationary phase. This phenomenon was not common to all bacteria tested and is not common to all strains with high radiation resistance. Four L. sake isolates and three reference strains were used in radiation sensitivity testing in a natural food system (i.e., meat). The bacteria were irradiated in minced meat and packaged under four different conditions (air, vacuum, CO/sub 2/, and N/sub 2/). Organisms exhibited the highest death rate (lowest D/sub 10/ values (doses required to reduce the logarithm of the bacterial population by 1) under CO/sub 2/ packaging conditions, but resistance to irradiation was increased under N/sub 2/. The D/sup 10/ values of the isolates were generally greater than those of the reference strains. The D/sup 10/ values were also higher (approximately two times) in meat than in a semisynthetic growth medium.

  7. Antibacterial properties of zeylasterone, a triterpenoid isolated from Maytenus blepharodes, against Staphylococcus aureus.

    Science.gov (United States)

    de León, L; López, M R; Moujir, L

    2010-10-20

    The anti-staphylococcal properties of zeylasterone and demethylzeylasterone, two 6-oxophenolic triterpenoids isolated from Maytenus blepharodes, were investigated. Zeylasterone was more active than demethylzeylasterone on Staphylococcus aureus cells, showing bactericidal activity at 30 μg/ml (6 × MIC) in less than three hours and bacteriostatic at lower concentrations. At the same cell density, a more drastic reduction in CFU count was obtained when the triterpenoid was incorporated into cultures growing actively. Zeylasterone at 3 × MIC added on S. aureus cultures showed an early inhibitory effect on incorporation of radiolabeled thymidine, uridina and N-acetyl-glucosamine, and later on leucine. It also caused cell membrane disruption in S. aureus, as shown by the inhibition of radiolabeled precursor uptake, rapid potassium leakage, inhibition of NADH oxidation, and formation of mesosome-like structures around the septa. The structural features of the molecule, the blockage of solute transport through the membrane and changes in its permeability, suggest that zeylasterone acts mainly on cytoplasmic membrane.

  8. Susceptibility profile of methicillin-resistant Staphylococcus aureus to linezolid in clinical isolates

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    Shariq, Ali; Tanvir, Syed Bilal; Zaman, Atif; Khan, Salman; Anis, Armeena; Khan, Misha Aftab; Ahmed, Sumaira

    2017-01-01

    Objective: To determine the resistance and sensitivity pattern of methicillin-resistant Staphylococcus aureus (MRSA) isolates to linezolid (LZD) along with its prevalence in a tertiary care hospital of Karachi, Pakistan. Materials and Methods: A cross-sectional study was carried out. This study lasted for about 1 year. Prevalence and sensitivity of LZD, vancomycin, and oxacillin was tested against isolates of MRSA. Results: Out of total 369 specimens 165 were found to be MRSA making the prevalence in our study 44.7%. All of the isolates which were tested positive for MRSA were susceptible to LZD and no resistance was noted when compared with previous studies performed in Europe and USA. Conclusion: Stringent implementation of infection control measures along with screening for resistance in patients on prolonged LZD therapy or who previously went under LZD therapy should be performed, coupled with judicious usage of the aforementioned antibiotic should be undertaken, as sufficient data is not available at this point for the clinical spectrum of LZD resistant S. aureus, antimicrobial resistance.

  9. Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus isolates from Trinidad & Tobago

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    Monteil Michele

    2006-07-01

    Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA has become increasingly prevalent worldwide since it was first reported in a British hospital. The prevalence however, varies markedly in hospitals in the same country, and from one country to another. We therefore sought to document comprehensively the prevalence and antimicrobial susceptibility pattern of MRSA isolates in Trinidad and Tobago. Methods All Staphylococcus aureus isolates encountered in routine clinical specimens received at major hospitals in the country between 2000 and 2001 were identified morphologically and biochemically by standard laboratory procedures including latex agglutination test (Staphaurex Plus; Murex Diagnostics Ltd; Dartford, England; tube coagulase test with rabbit plasma (Becton, Dickinson & Co; Sparks, MD, USA, and DNase test using DNase agar (Oxoid Ltd; Basingstoke, Hampshire, England. MRSA screening was performed using Mueller-Hinton agar containing 6 μg oxacillin and 4% NaCl, latex agglutination test (Denka Seiken Co. Ltd, Tokyo, Japan and E-test system (AB Biodisk, Solna, Sweden. Susceptibility to antimicrobial agents was determined by the modified Kirby Bauer disc diffusion method while methicillin MICs were determined with E-test system. Results Of 1,912 S. aureus isolates received, 12.8% were methicillin (oxacillin resistant. Majority of the isolates were recovered from wound swabs (86.9% and the least in urine (0.4% specimens. Highest number of isolates was encountered in the surgical (62.3% and the least from obstetrics and gynaecology (1.6% facilities respectively. Large proportions of methicillin sensitive isolates are >85% sensitive to commonly used and available antimicrobials in the country. All MRSA isolates were resistant to ceftriaxone, erythromycin, gentamicin and penicillin but were 100% sensitive to vancomycin, rifampin and chloramphenicol. Conclusion There is a progressive increase in MRSA prevalence in the country but

  10. Heavy metal and disinfectant resistance genes among livestock-associated methicillin-resistant Staphylococcus aureus isolates.

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    Argudín, M Angeles; Lauzat, Birgit; Kraushaar, Britta; Alba, Patricia; Agerso, Yvonne; Cavaco, Lina; Butaye, Patrick; Porrero, M Concepción; Battisti, Antonio; Tenhagen, Bernd-Alois; Fetsch, Alexandra; Guerra, Beatriz

    2016-08-15

    Livestock associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has emerged in animal production worldwide. Most LA-MRSA in Europe belong to the clonal complex (CC) 398. The reason for the LA-MRSA emergence is not fully understood. Besides antimicrobial agents used for therapy, other substances with antimicrobial activity applied in animal feed, including metal-containing compounds might contribute to their selection. Some of these genes have been found in various novel SCCmec cassettes. The aim of this study was to assess the occurrence of metal-resistance genes among a LA-S. aureus collection [n=554, including 542 MRSA and 12 methicillin-susceptible S. aureus (MSSA)] isolated from livestock and food thereof. Most LA-MRSA isolates (76%) carried at least one metal-resistance gene. Among the LA-MRSA CC398 isolates (n=456), 4.8%, 0.2%, 24.3% and 71.5% were positive for arsA (arsenic compounds), cadD (cadmium), copB (copper) and czrC (zinc/cadmium) resistance genes, respectively. In contrast, among the LA-MRSA non-CC398 isolates (n=86), 1.2%, 18.6% and 16.3% were positive for the cadD, copB and czrC genes, respectively, and none were positive for arsA. Of the LA-MRSA CC398 isolates, 72% carried one metal-resistance gene, and the remaining harboured two or more in different combinations. Differences between LA-MRSA CC398 and non-CC398 were statistically significant for arsA and czrC. The czrC gene was almost exclusively found (98%) in the presence of SCCmec V in both CC398 and non-CC398 LA-MRSA isolates from different sources. Regarding the LA-MSSA isolates (n=12), some (n=4) were also positive for metal-resistance genes. This study shows that genes potentially conferring metal-resistance are frequently present in LA-MRSA.

  11. Spread of a methicillin-resistant Staphylococcus aureus ST80 strain in the community of the northern Netherlands

    NARCIS (Netherlands)

    Stam-Bolink, E. M.; Mithoe, D.; Arends, J. P.; Moller, A. V. M.

    2007-01-01

    Infections caused by community-acquired methicillin-resistant Staphylococcus aureus (MRSA) are emerging as a major public health problem. In this study, we describe the distribution of 54 Panton-Valentine leucocidin (PVL)-carrying MRSA isolates in the northern Netherlands between 1998 and 2005, of w

  12. Complete Genome Sequences of Two Methicillin-Sensitive Staphylococcus aureus Isolates Representing a Population Subset Highly Prevalent in Human Colonization.

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    Weber, Robert E; Layer, Franziska; Fuchs, Stephan; Bender, Jennifer K; Fiedler, Stefan; Werner, Guido; Strommenger, Birgit

    2016-01-01

    Here, we report the high-quality draft genome sequences of two methicillin-susceptible Staphylococcus aureus isolates, 08-02119 and 08-02300. Belonging to sequence type 582 (ST582) and ST7, both isolates are representatives of clonal lineages often associated with asymptomatic colonization of humans.

  13. Complete Genome Sequences of Two Methicillin-Sensitive Staphylococcus aureus Isolates Representing a Population Subset Highly Prevalent in Human Colonization

    Science.gov (United States)

    Weber, Robert E.; Layer, Franziska; Fuchs, Stephan; Bender, Jennifer K.; Fiedler, Stefan; Werner, Guido

    2016-01-01

    Here, we report the high-quality draft genome sequences of two methicillin-susceptible Staphylococcus aureus isolates, 08-02119 and 08-02300. Belonging to sequence type 582 (ST582) and ST7, both isolates are representatives of clonal lineages often associated with asymptomatic colonization of humans. PMID:27469954

  14. Prevalence of genes encoding for members of the staphylococcal leukotoxin family among clinical isolates of Staphylococcus aureus

    NARCIS (Netherlands)

    von Eiff, Christof; Friedrich, Alexander W.; Peters, Georg; Becker, Karsten

    2004-01-01

    Well-characterized Staphylococcus aureus nasal and blood isolates (N = 429) were tested by polymerase chain reaction for the prevalence of genes that encode leukocidal toxins. The leukotoxin genes lukE+lukD were found at high prevalence, significantly more so in blood (82%) than in nasal isolates (6

  15. Comparison of genotypes and enterotoxin genes between Staphylococcus aureus isolates from blood and nasal colonizers in a Korean hospital.

    Science.gov (United States)

    Peck, Kyong Ran; Baek, Jin Yang; Song, Jae-Hoon; Ko, Kwan Soo

    2009-08-01

    In this study, we investigated the genetic background of 70 Staphylococcus aureus isolates (36 methicillin-resistant S. aureus [MRSA] and 34 methicillin-susceptible S. aureus [MSSA]) obtained from blood at a Korean tertiary-care hospital, using spa typing, multilocus sequence typing, and SCCmec typing. In addition, the prevalence of enterotoxin (sea, seb, sec, sed, see, seg, seh, sei, and sek), tst, and pvl genes among the samples was assessed via polymerase chain reaction, and the results were compared with those of 95 isolates of S. aureus obtained from nasal swabs. All MRSA isolates from blood, except one, belonged to three major clones: sequence type (ST)5-MRSA-II, ST72-MRSA-II (or IVA), and ST239-MRSA-III, among which ST5-MRSA-II was the predominant clone. The prevalence of enterotoxin genes in the S. aureus isolates obtained from blood differed significantly from those from the nasal swabs for the sea, seb, sec, and seh gene. In particular, the seb and sec genes were detected exclusively in the MRSA isolates of ST5 or spa-CC002, thereby suggesting the co-adaptation of virulence genes with the genetic background and their contribution to biological fitness.

  16. Genetic variations among Mycoplasma bovis strains isolated from Danish cattle

    DEFF Research Database (Denmark)

    Kusiluka, L.J.M.; Kokotovic, Branko; Ojeniyi, B.

    2000-01-01

    The genetic heterogeneity of Mycoplasma bovis strains isolated in Denmark over a 17-year period was investigated. Forty-two field strains isolated from different geographic locations and specimens, including strains from 21 herds involved in two outbreaks of M. bovis-induced mastitis, and the type...... strain of M. bovis (PG45(T)) were assayed for variations in the BglII and MfeI restriction sites in the chromosomal DNA by using the amplified fragment length polymorphism (AFLP) fingerprinting technique. The obtained genomic fingerprints consisted of 62-68 AFLP fragments in the size range of 50-500 bp...... 2 years apart; showed indistinguishable AFLP patterns. More genetic diversify was observed among the recent strains. The similarity of the genotypes of the field strains to that of the M. bovis type strain (PG45(T)) was 97.7%. The results of this study have demonstrated a remarkable genomic...

  17. Metabolic activities of Lactobacillus spp. strains isolated from kefir.

    Science.gov (United States)

    Yüksekdag, Zehra Nur; Beyath, Yavuz; Aslim, Belma

    2004-06-01

    A total of 21 strains of Lactobacillus species were isolated from Turkish kefir samples, in order to select the most suitable strains according to their metabolic activities including probiotic properties. As a result of the identification tests, 21 Lactobacillus isolates were identified as L. acidophilus (4%), L. helveticus (9%), L. brevis (9%), L. bulgaricus (14%), L. plantarum (14%), L. casei (19%) and L. lactis (28%). The amount of produced lactic acid, hydrogen peroxide, proteolytic activity, and acetaldehyde productions of Lactobacillus spp. were determined. Different amounts of lactic acid were produced by strains studies; however, lactic acid levels were 1.7-11.4 mg/mL. All strains produced hydrogen peroxide. L. bulgaricus Z14L strain showed no proteolytic activity, L. casei Z6L strain produced the maximum amount (0.16 mg/mL) of proteolytic activity. Acetaldehyde concentration produced in Lactobacillus strains ranged between 0.88-3.52 microg/mL.

  18. Antimicrobial activity of ceftaroline against methicillin-resistant Staphylococcus aureus (MRSA) isolates collected in 2013-2014 at the Geneva University Hospitals.

    Science.gov (United States)

    Andrey, D O; François, P; Manzano, C; Bonetti, E J; Harbarth, S; Schrenzel, J; Kelley, W L; Renzoni, A

    2017-02-01

    Ceftaroline is a broad-spectrum antibiotic with activity against methicillin-resistant Staphylococcus aureus (MRSA) strains. Ceftaroline susceptibility of an MRSA set archived between 1994 and 2003 in the Geneva University Hospitals detected a high percentage (66 %) of ceftaroline resistance in clonotypes ST228 and ST247 and correlated with mutations in PBP2a. The ceftaroline mechanism of action is based on the inhibition of PBP2a; thus, the identification of PBP2a mutations of recently circulating clonotypes in our institution was investigated. We analyzed ceftaroline susceptibility in MRSA isolates (2013 and 2014) and established that resistant strains correlated with PBP2a mutations and specific clonotypes. Ninety-six MRSA strains were analyzed from independent patients and were isolated from blood cultures (23 %), deep infections (38.5 %), and superficial (skin or wound) infections (38.5 %). This sample showed a ceftaroline minimum inhibitory concentration (MIC) range between 0.25 and 2 μg/ml and disk diameters ranging from 10 to 30 mm, with a majority of strains showing diameters ≥20 mm. Based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, 76 % (73/96) of isolates showed susceptibility to ceftaroline. Nevertheless, we still observed 24 % (23/96) of resistant isolates (MIC = 2 μg/ml). All resistant isolates were assigned to clonotype ST228 and carried the N146K mutation in PBP2a. Only two ST228 isolates showed ceftaroline susceptibility. The decreasing percentage of ceftaroline-resistant isolates in our hospital can be explained by the decline of ST228 clonotype circulating in our hospital since 2008. We present evidence that ceftaroline is active against recent MRSA strains from our hospital; however, the presence of PBP2a variants in particular clonotypes may affect ceftaroline efficacy.

  19. First report of the predominance of clonal complex 398 Staphylococcus aureus strains in osteomyelitis complicating diabetic foot ulcers: a national French study.

    Science.gov (United States)

    Senneville, E; Brière, M; Neut, C; Messad, N; Lina, G; Richard, J-L; Sotto, A; Lavigne, J-P

    2014-04-01

    Staphylococcus aureus is the most common pathogen cultured from diabetic foot infection including diabetic foot osteomyelitis. This French multicentre study determined the genetic content of S. aureus isolated from 157 consecutive cases admitted to 12 diabetic foot centres between 2008 and 2011. We describe for the first time the emergence of the CC398 methicillin-susceptible S. aureus clone, the main clone in diabetic foot osteomyelitis, and its tropism for bone. This clone spreads to humans from an animal source through its intrinsic virulence. This adaptation of S. aureus isolates looks to be a worrisome problem and should be carefully monitored.

  20. Molecular typing and phenotype characterization of methicillin-resistant Staphylococcus aureus isolates from blood in Taiwan.

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    Wei-Yao Wang

    Full Text Available BACKGROUND: Staphylococcus aureus causes a variety of severe infections such as bacteremia and sepsis. At present, 60-80% of S. aureus isolates from Taiwan are methicillin resistant (MRSA. It has been shown that certain MRSA clones circulate worldwide. The goals of this study were to identify MRSA clones in Taiwan and to correlate the molecular types of isolates with their phenotypes. METHODS: A total of 157 MRSA isolates from bacteremic patients were collected from nine medical centers. They were typed based on polymorphisms in agr, SCCmec, MLST, spa, and dru. Phenotypes characterized included Panton-Valentine leucocidin (pvl, inducible macrolide-lincosamide-streptogramin B resistance (MLSBi, vancomycin (VA and daptomycin (DAP minimal inhibitory concentrations (MIC, and superantigenic toxin gene profiles. Difference between two consecutive samples was determined by Mann-Whitney-U test, and difference between two categorical variables was determined by Fisher's exact test. RESULTS: Four major MRSA clone complexes CC1, CC5, CC8, and CC59 were found, including 4 CC1, 9 CC5, 111 CC8, and 28 CC59 isolates. These clones had the following molecular types: CC1: SCCmecIV and ST573; CC5: SCCmecII and ST5; CC8: SCCmecIII, ST239, and ST241, and CC59: SCCmecIV, SCCmecV(T, ST59, and ST338. The toxin gene profiles of these clones were CC1: sec-seg-(sei-sell-selm-(seln-selo; CC5: sec-seg-sei-sell-selm-(seln-selp-tst1; CC8: sea-selk-selq, and CC59: seb-selk-selq. Most isolates with SCCmecV(T, ST59, spat437, and dru11 types were pvl(+ (13 isolates, while multidrug resistance (≥4 antimicrobials were associated with SCCmecIII, ST239, spa t037, agrI, and dru14 (119 isolates (p<0.001. One hundred and twenty four isolates with the following molecular types had higher VA MIC: SCCmecII and SCCmecIII; ST5, ST239, and ST241; spa t002, t037, and t421; dru4, dru10, dru12, dru13, and dru14 (p<0.05. No particular molecular types were found to be associated with MLSBi

  1. Molecular Typing of Staphylococcus Aureus Isolate Responsible for Staphylococcal Poisoning Incident in Homemade Food.

    Science.gov (United States)

    Macori, Guerrino; Bellio, Alberto; Bianchi, Daniela Manila; Gallina, Silvia; Adriano, Daniela; Zuccon, Fabio; Chiesa, Francesco; Acutis, Pier Luigi; Casalinuovo, Francesco; Decastelli, Lucia

    2016-04-19

    In October 2012, two persons fell ill with symptoms consistent with staphylococcal food poisoning after eating home-canned tuna fish and tomatoes. Laboratory investigation detected the enterotoxins in the home-canned tuna and molecular analysis of the isolated Staphylococcus aureus confirmed it carried toxin genes. Qualitative enzyme-linked immunosorbent assay and enzime linked fluorescent assay methods and quantitative assay identified the enterotoxins in the food leftovers, specifically staphylococcal enterotoxins type A (SEA) and D (SED), respectively 0.49 and 2.04 ng/g. The laboratory results are discussed considering the relation to the fish in oil, survival and heat resistance of S. aureus, and presumptive microbial contamination due to improper handling during home-canning procedures. This is the first reported cluster of foodborne illnesses due to staphylococcal enterotoxins in tuna in Italy. In this study, we reported cases described and analysed for their spa-type. Showing a high heterogeneity of isolates, spa-type t13252 is correlated in a node of the minimum spanning tree and it has never been reported as responsible for foodborne outbreak. This case underlines the importance of risk communication and dissemination of home-canning guidelines to reduce the incidence of foodborne outbreaks caused by homemade conserves.

  2. Molecular typing of Staphylococcus aureus isolate responsible for staphylococcal poisoning incident in homemade food

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    Guerrino Macori

    2016-06-01

    Full Text Available In October 2012, two persons fell ill with symptoms consistent with staphylococcal food poisoning after eating home-canned tuna fish and tomatoes. Laboratory investigation detected the enterotoxins in the home-canned tuna and molecular analysis of the isolated Staphylococcus aureus confirmed it carried toxin genes. Qualitative enzyme-linked immunosorbent assay and enzime linked fluorescent assay methods and quantitative assay identified the enterotoxins in the food leftovers, specifically staphylococcal enterotoxins type A (SEA and D (SED, respectively 0.49 and 2.04 ng/g. The laboratory results are discussed considering the relation to the fish in oil, survival and heat resistance of S. aureus, and presumptive microbial contamination due to improper handling during home-canning procedures. This is the first reported cluster of foodborne illnesses due to staphylococcal enterotoxins in tuna in Italy. In this study, we reported cases described and analysed for their spa-type. Showing a high heterogeneity of isolates, spa-type t13252 is correlated in a node of the minimum spanning tree and it has never been reported as responsible for foodborne outbreak. This case underlines the importance of risk communication and dissemination of home-canning guidelines to reduce the incidence of foodborne outbreaks caused by homemade conserves.

  3. Molecular Typing of Staphylococcus Aureus Isolate Responsible for Staphylococcal Poisoning Incident in Homemade Food

    Science.gov (United States)

    Bellio, Alberto; Bianchi, Daniela Manila; Gallina, Silvia; Adriano, Daniela; Zuccon, Fabio; Chiesa, Francesco; Acutis, Pier Luigi; Casalinuovo, Francesco; Decastelli, Lucia

    2016-01-01

    In October 2012, two persons fell ill with symptoms consistent with staphylococcal food poisoning after eating home-canned tuna fish and tomatoes. Laboratory investigation detected the enterotoxins in the home-canned tuna and molecular analysis of the isolated Staphylococcus aureus confirmed it carried toxin genes. Qualitative enzyme-linked immunosorbent assay and enzime linked fluorescent assay methods and quantitative assay identified the enterotoxins in the food leftovers, specifically staphylococcal enterotoxins type A (SEA) and D (SED), respectively 0.49 and 2.04 ng/g. The laboratory results are discussed considering the relation to the fish in oil, survival and heat resistance of S. aureus, and presumptive microbial contamination due to improper handling during home-canning procedures. This is the first reported cluster of foodborne illnesses due to staphylococcal enterotoxins in tuna in Italy. In this study, we reported cases described and analysed for their spa-type. Showing a high heterogeneity of isolates, spa-type t13252 is correlated in a node of the minimum spanning tree and it has never been reported as responsible for foodborne outbreak. This case underlines the importance of risk communication and dissemination of home-canning guidelines to reduce the incidence of foodborne outbreaks caused by homemade conserves.

  4. Isolation, identification and characterization of regional indigenous Saccharomyces cerevisiae strains

    Science.gov (United States)

    Šuranská, Hana; Vránová, Dana; Omelková, Jiřina

    2016-01-01

    In the present work we isolated and identified various indigenous Saccharomyces cerevisiae strains and screened them for the selected oenological properties. These S. cerevisiae strains were isolated from berries and spontaneously fermented musts. The grape berries (Sauvignon blanc and Pinot noir) were grown under the integrated and organic mode of farming in the South Moravia (Czech Republic) wine region. Modern genotyping techniques such as PCR-fingerprinting and interdelta PCR typing were employed to differentiate among indigenous S. cerevisiae strains. This combination of the methods provides a rapid and relatively simple approach for identification of yeast of S. cerevisiae at strain level. In total, 120 isolates were identified and grouped by molecular approaches and 45 of the representative strains were tested for selected important oenological properties including ethanol, sulfur dioxide and osmotic stress tolerance, intensity of flocculation and desirable enzymatic activities. Their ability to produce and utilize acetic/malic acid was examined as well; in addition, H2S production as an undesirable property was screened. The oenological characteristics of indigenous isolates were compared to a commercially available S. cerevisiae BS6 strain, which is commonly used as the starter culture. Finally, some indigenous strains coming from organically treated grape berries were chosen for their promising oenological properties and these strains will be used as the starter culture, because application of a selected indigenous S. cerevisiae strain can enhance the regional character of the wines. PMID:26887243

  5. An analysis on drug resistance of 108 staphylococcus aureus strains%对108株金黄色葡萄球菌的耐药性分析

    Institute of Scientific and Technical Information of China (English)

    叶小清; 黄嫦娥

    2011-01-01

    Objective To instruct clinicians to prescribe medications more logically by investigating the antibiotic resistance and current infection status of staphylococcus aureus isolates.Methods Drug sensitivity testing was conducted in 108 staphylococcus aureus stains isolated from our hospital during the period of November 2009 to September 2011.Results 76 of 108 (70.4%) strains were methicillin-resistant staphylo-coccus aureus,while 32 (29.6%) were methicillin- sensitive.The strains (43A%) were mainly isolated from sputum or throat swab,and 35.9% from pus or wound.21.7% of the strains were isolated from vaginal discharges,blood,urine,and semen.The highest rate of staphylococcus aureus MRSA to 16 kinds of antimicrobial resistance was penicillin and oxacillin both acounted for 100.0%,and penicillin-resistant MSSA only the high rate for 83.2%,other 15 drug resistance rates were low at 50%.Vancomycin,nitrofurantoin,teicoplanin resistance rates in both were 0.Conclusions methieillin-sensitive Staphylococcus aureus have good sensitivity for most of the antibiotics in addition to penicillin,and methicillin-resistant Staphylococcus aureus detection rate is still high and more for multi-drug resistance.%目的 了解我院金黄色葡萄球菌临床分离株对抗菌药物的耐药性及感染现状,以指导临床医生更科学合理用药.方法 收集我院2009年11月- 2011年9月间住院及门诊患者的标本,对分离出的108株金黄色葡萄球菌进行药敏试验.结果 对甲氧西林耐药的金黄色葡萄球菌(MRSA)有76株,占70.4%;对甲氧西林敏感的金黄色葡萄球菌(MSSA)有32株,占29.6%.菌株主要分离于痰液/咽拭子,占42.6%;其次是分离于脓液/创面,占36.1%;其他的菌株分离于阴道分泌物、血液、尿液和精液,占21.3%.金黄色葡萄球菌中MRSA对16种抗菌药物的耐药率最高的是青霉素和苯唑西林,均为100.0%,而MSSA仅对青霉素的耐药率较高,达83.2

  6. Molecular Typing of Staphylococcus aureus Isolated From Clinical Specimens During an Eight-Year Period (2005 - 2012 in Tabriz, Iran

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    Ahangarzadeh Rezaee

    2016-03-01

    Full Text Available Background Antibiotic resistant Staphylococcus aureus is a serious public health problem worldwide. Objectives This study aimed to investigate the susceptibility pattern and molecular typing of S. aureus isolated from clinical specimens of hospitalized patients during eight years, from 2005 to 2012. Materials and Methods A total of 151 randomly selected S. aureus isolates, identified with phenotypic tests and detection of nuc gene, were subjected to antimicrobial susceptibility testing using the disk diffusion method. Moreover, molecular typing of the isolates was carried out by PCR-RFLP based on coa and spa genes. Results All isolates were susceptible to vancomycin and teicoplanin. High rates of susceptibility were also observed with rifampin (98.1%, imipenem (94.7%, and linezolid (94.1%. On the other hand, most of the isolates were resistant against penicillin (95.4%, erythromycin (68.9% and clindamycin (57.6%. Four types of spa and coa were distinguished among the isolates based on PCR results; however, the HaeII digestion resulted in a total of sixteen and nine RFLP patterns for spa and coa genes, respectively. Conclusions The outcome of this study indicates a higher discriminatory power of the RFLP analysis based on the spa gene compared to the coa gene. Moreover, the results of our study reveal that the resistance rate of S. aureus to some antimicrobial agents including linezolid is a growing concern.

  7. Antibacterial Activity of Phytochemicals Isolated from Atractylodes japonica against Methicillin-Resistant Staphylococcus aureus

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    Seung-Ho Hang

    2010-10-01

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA has been emerging worldwide as one of the most important problems in communities and hospitals. Therefore, new agents are needed to treat acute oral infections from MRSA. In this study, antibacterial compounds from the roots of Atractylodes japonica (A. japonica were isolated and characterized. The compounds were isolated from the root extracts using HPLC-piloted activity-guided fractionations. Four A. japonica compounds were isolated and identified as atractylenolide III (1, atractylenolide I (2, diacetylatractylodiol [(6E,12E-tetradeca-6,12-diene-8,10-diyne-1,3-diol diacetate, TDEYA, 3. and (6E,12E-tetradecadiene-8,10-diyne-1,3-diol (TDEA, 4, which was obtained by hydrolysis of TDEYA. The minimum inhibitory concentrations (MICs was determined in the setting of clinical MRSA isolates. Compound 4 showed anti-MRSA activity with a MIC value of 4-32 μg/mL. The overall results provide promising baseline information for the potential use of the extract of A. japonica as well as some of the isolated compounds in the treatment of bacterial infections.

  8. Detection of Methicillin Resistant Staphylococcus aureus and Determination of Minimum Inhibitory Concentration of Vancomycin for Staphylococcus aureus Isolated from Pus/Wound Swab Samples of the Patients Attending a Tertiary Care Hospital in Kathmandu, Nepal

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    Raghabendra Adhikari

    2017-01-01

    Full Text Available The present study was conducted to evaluate the performance of cefoxitin disc diffusion method and oxacillin broth microdilution method for detection of methicillin resistant S. aureus (MRSA, taking presence of mecA gene as reference. In addition, inducible clindamycin resistance and beta-lactamase production were studied and minimum inhibitory concentration (MIC of vancomycin for S. aureus isolates was determined. A total of 711 nonrepeated pus/wound swab samples from different anatomic locations were included in the study. The Staphylococcus aureus was identified on the basis of colony morphology, Gram’s stain, and biochemical tests. A total of 110 (15.47% S. aureus isolates were recovered, of which 39 (35.50% isolates were identified as MRSA by cefoxitin disc diffusion method. By oxacillin broth microdilution method, 31.82% of the Staphylococcus aureus isolates were found to be MRSA. However, mecA gene was present in only 29.1% of the isolates. Further, beta-lactamase production was observed in 71.82% of the isolates, while inducible clindamycin resistance was found in 10% of S. aureus isolates. The MIC value of vancomycin for S. aureus ranged from 0.016 μg/mL to 1 μg/mL. On the basis of the absolute sensitivity (100%, both phenotypic methods could be employed for routine diagnosis of MRSA in clinical microbiology laboratory; however cefoxitin disc diffusion could be preferred over MIC method considering time and labour factor.

  9. Detection of Methicillin Resistant Staphylococcus aureus and Determination of Minimum Inhibitory Concentration of Vancomycin for Staphylococcus aureus Isolated from Pus/Wound Swab Samples of the Patients Attending a Tertiary Care Hospital in Kathmandu, Nepal

    Science.gov (United States)

    Adhikari, Raghabendra; Neupane, Sanjeev; Neupane, Mukesh; Bhattarai, Roshan; Bhatta, Sabita; Chaudhary, Raina; Lekhak, Binod

    2017-01-01

    The present study was conducted to evaluate the performance of cefoxitin disc diffusion method and oxacillin broth microdilution method for detection of methicillin resistant S. aureus (MRSA), taking presence of mecA gene as reference. In addition, inducible clindamycin resistance and beta-lactamase production were studied and minimum inhibitory concentration (MIC) of vancomycin for S. aureus isolates was determined. A total of 711 nonrepeated pus/wound swab samples from different anatomic locations were included in the study. The Staphylococcus aureus was identified on the basis of colony morphology, Gram's stain, and biochemical tests. A total of 110 (15.47%) S. aureus isolates were recovered, of which 39 (35.50%) isolates were identified as MRSA by cefoxitin disc diffusion method. By oxacillin broth microdilution method, 31.82% of the Staphylococcus aureus isolates were found to be MRSA. However, mecA gene was present in only 29.1% of the isolates. Further, beta-lactamase production was observed in 71.82% of the isolates, while inducible clindamycin resistance was found in 10% of S. aureus isolates. The MIC value of vancomycin for S. aureus ranged from 0.016 μg/mL to 1 μg/mL. On the basis of the absolute sensitivity (100%), both phenotypic methods could be employed for routine diagnosis of MRSA in clinical microbiology laboratory; however cefoxitin disc diffusion could be preferred over MIC method considering time and labour factor.

  10. Atividade biológica da jurema-preta (Mimosa tenuiflora (Wild Poir. sobre Staphylococcus aureus isolado de casos de mastite bovina Biological Activity of jurema preta (Mimosa tenuiflora (Wild Poiret on Staphylococcus aureus isolated of mastitis cattle

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    Denise A. C. Bezerra

    2009-12-01

    Full Text Available O objetivo deste estudo foi avaliar a sensibilidade do Staphylococcus aureus ao extrato da jurema-preta (Mimosa tenuiflora (Wild Poir.. Foram isoladas 25 cepas de S. aureus de amostras de leite de vacas com histórico de mastite clínica e subclínica, submetidas ao teste de atividade antimicrobiana do extrato de M. tenuiflora. Os testes de sensibilidade in vitro foram realizados utilizando o método de difusão em meio sólido. Em seguida foram inoculados 50 μL do extrato nas seguintes diluições 1:1; 1:2; 1:4; 1:8; 1:16; 1:32; 1:64; 1:128; 1:256; 1:512. As placas foram incubadas a 37 °C, por um período de 24 a 48 h. Os ensaios foram realizados em triplicata. Observou-se halos de inibição entre 6 e 25 mm de diâmetro. O percentual de sensibilidade das amostras testadas foi distribuido em: 1:1 a 1:32 (100%; 1:64 (92%; 1: 128 (72%; 1:256 (28%; 1:512 (0%. O estudo da M. tenuiflora sobre as amostras de S. aureus testadas demonstrou que a planta tem ação antimicrobiana.The aim of this study was to evaluate the sensitivity of the S.aureus to the extract of Mimosa tenuiflora (Wild Poir. (jurema-preta. Twenty five strains of S. aureus were isolated from milk samples with description of clinical and subclinical mastitis and submitted to antimicrobial activity test of the M. tenuiflora extract. The sensitivity in vitro tests were carried out using the agar difusion method (well diffusion method. After that, 50μL of the extract were inoculated in the following dilutions: 1:1; 1:2; 1:4; 1:8; 1:16; 1:32; 1:64; 1:128; 1:256; 1:512. The plates were incubated at 37 ºC during 24 and 48 h. The tests were made in triplicate. Halos of inhibition were observed between 6 and 25 mm of diameter. The percentage of sensitivity of the tested samples was distributed in: 1:1 to 1:32 (100%, 1:64 (92%; 1: 128 (72%; 1:256 (28%; 1:512 (0%. The study of M. tenuiflora on the tested S. aureus samples it demonstrated that the plant has antimicrobial action.

  11. In vitro activity of ceftobiprole, linezolid, tigecycline, and 23 other antimicrobial agents against Staphylococcus aureus isolates in China.

    Science.gov (United States)

    Wang, Hui; Liu, Yudong; Sun, Hongli; Xu, Yingchun; Xie, Xiuli; Chen, Minjun

    2008-10-01

    We investigated the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in China and determined the susceptibility of S. aureus to 26 antimicrobial agents, including ceftobiprole, linezolid, and tigecycline. A total of 798 isolates were collected and tested by agar dilution. The mean prevalence of MRSA was 50.4%, the highest in Shanghai (80.3%), followed by those in Beijing (55.5%) and Shenyang (50.0%). Only 4.2% to 12.6% of MRSA were susceptible to erythromycin, fluoroquinolones, gentamicin, and tetracycline. All isolates were susceptible to teicoplanin, vancomycin, linezolid, tigecycline, and ceftobiprole.

  12. PROPERTIES OF NEW STRAINS CHEMOLITHOTROPHIC BACTERIA ISOLATED FROM INDUSTRIAL SUBSTRATES

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    I. A.

    2015-12-01

    Full Text Available The purpose of the research was determination of strains Acidithiobacillus ferrooxidans MFLv37 and Acidithiobacillus ferrooxidans MFLad27, isolated from aboriginal consortium of coal beneficiation dumps and fly ash from coal combustion, resistance to heavy metals, forming part of these waste, as well as adaption ability of the strains to new substrates. New strains increased resistance to heavy metal ions as compared to A. ferrooxidans standard and collection strains is found; minimal inhibitory concentrations of heavy and toxic metals are determined; a number of metals that have negative impact on growth of isolated cultures are identified. It is shown that the minimal metals concentrations, at which strains growth still happens, are several times higher than their concentrations in technogenic waste. It has been established that isolated strains differed in their ability to adapt, as well as in growth rate and substrates oxidation. This is due to the specific conditions of microbiocenoses formation in making and further storage of rock dumps and fly ash, whereof the appropriate strains are isolated. The investigations indicate the necessity in directional selection of strains that are resistant to the toxic compounds and are able to oxidize various mineral substrates, as well as in their adaptation to new substrates for the extraction of heavy metals.

  13. Phenotypes and genotypes of old and contemporary porcine strains indicate a temporal change in the S. aureus population structure in pigs

    NARCIS (Netherlands)

    Espinosa-Gongora, Carmen; Moodley, Arshnee; Lipinska, Urszula; Broens, Els M; Hermans, Katleen; Butaye, Patrick; Devriese, Luc A; Haesebrouck, Freddy; Guardabassi, Luca

    2014-01-01

    INTRODUCTION: Staphylococcus aureus sequence type ST398 has recently gained attention due to the spread of methicillin-resistant strains among people exposed to livestock. The aim of this study was to explore temporal changes in the population structure of S. aureus in pigs over the last 40 years wi

  14. Phenotypes and genotypes of old and contemporary porcine strains indicate a temporal change in the S. aureus population structure in pigs

    DEFF Research Database (Denmark)

    Gongora, Carmen Espinosa; Moodley, Arshnee; Lipinska, Urszula

    2014-01-01

    INTRODUCTION: Staphylococcus aureus sequence type ST398 has recently gained attention due to the spread of methicillin-resistant strains among people exposed to livestock. The aim of this study was to explore temporal changes in the population structure of S. aureus in pigs over the last 40 years...

  15. Antimicrobial activity of Mimosa tenuiflora (Willd. Poir. from Northeast Brazil against clinical isolates of Staphylococcus aureus Atividade antimicrobiana de Mimosa tenuiflora (Willd. Poir. do Nordeste do Brasil, contra isolados clínicos de Staphylococcus aureus

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    Itácio Q. M. Padilha

    2010-03-01

    Full Text Available Mimosa tenuiflora is a native plant of Northeast Brazil where it is popularly known as ''jurema-preta'' and it is widely used in folk medicine. In this work the anti-Staphylococcus aureus activity of ethanol extract of M tenuiflora was evaluated by determination of minimum inhibitory concentration (MIC of clinical isolates by the agar dilution method, and by time-kill assay using a reference strain. MIC values against 30 isolates were 0,18 mg/mL (16/30 or 0,36 mg/mL (14/30, and also the reference strain. In the reference strains, at concentrations up to 4x MIC, only bacteriostatic effect was observed, but at 8x MIC a fast bactericidal effect was observed.A Mimosa tenuiflora é uma planta nativa da região Nordeste do Brasil onde é conhecida como jurema-preta sendo amplamente utilizada na medicina popular. No presente trabalho a atividade anti-Staphylococcus aureus do extrato etanólico da M. tenuiflora foi avaliada pela determinação da concentração inibitória mínima (CIM, pelo método da diluição em agar, em 30 isolados clínicos e pela cinética de inativação com a linhagem referência. Os valores da CIM foram 0,18 mg/mL em 16 isolados e 0,36 mg/mL nos demais, bem como na linhagem referência. A cinética de inativação mostrou apenas efeito bacteriostático nas concentrações do extrato até aquela correspondente a 4x CIM e um rápido efeito bactericida na concentração correspondente a 8x CIM.

  16. 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.

  17. Epidemiological features, resistance genes, and clones among community-onset methicillin-resistant Staphylococcus aureus (CO-MRSA) isolates detected in northern Spain.

    Science.gov (United States)

    González-Domínguez, María; Seral, Cristina; Sáenz, Yolanda; Salvo, Soledad; Gude, María José; Porres-Osante, Nerea; Torres, Carmen; Castillo, Francisco Javier

    2012-12-01

    Twenty-nine community-onset methicillin-resistant Staphylococcus aureus (CO-MRSA) isolates were prospectively selected according to epidemiological criteria among 374 MRSA isolates collected in our laboratory during 2009-2010 in order to determine which community-associated MRSA (CA-MRSA) and healthcare-associated MRSA (HA-MRSA) clones are circulating in the community in northern Spain. PVL genes were detected in 5 strains (17.2%) that belonged to SCCmec type IV or V and to the agr group I (ST8 and ST2050), agr group II (ST121), and agr group III (ST30 and ST852). These strains were isolated from patients with different clinical manifestations such as urinary tract infection, abscess, or pneumonia, and most of them belonged to emergency department patients with no history of visits to General Practitioners (GPs) in the year before the isolation. We considered that the prevalence of CA-MRSA in community-onset isolates was low (17.2%). A high proportion of the CO-MRSA strains (58.6%) were ST125-MRSA-IVc (CC5), responsible for most of the infections caused by HA-MRSA strains in Spain. This endemic clone is also circulating in the community of northern Spain as we could demonstrate in this study. Antimicrobial resistance was found in spa type t067 isolates linked to the presence of ant(4')-Ia and msr(A). Most of the CO-MRSA isolates in this study corresponded to spa types more associated to the hospital environment, suggesting the interchange of genetic lineages of MRSA among community and hospital niches.

  18. Virulence factors and antimicrobial resistance of Staphylococcus aureus isolated from bovine mastitis in Rio de Janeiro Fatores de virulência e resistência antimicrobiana em Staphylococcus aureus isolados de mastite bovina no Rio de Janeiro

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    Shana M.O. Coelho

    2009-05-01

    Full Text Available The study was conducted to characterize pheno-genotypically the virulence factors and resistance pattern of Staphylococcus aureus isolates from milk samples of cows with subclinical mastitis. All hemolytic isolates presented beta-hemolysin, and 38% of the non-hemolytic isolates were able to express hemolysins in the presence of a beta-hemolytic strain. The amplification of the coa-gene displayed four different size polymorphisms with about 400 bp, 600 bp, 700 bp and 900 bp. The spaA gene that encodes the IgG-binding region of protein A revealed sizes of 700 bp and 900 bp. The amplification of region X from spaA yielded a single amplicon for each isolate with the prevalent amplicon size being of 180 bp. Amplification of sae gene yielded an amplicon size of 920 bp in 71% of the isolates. Antibiotic resistance pattern revealed that 42% S. aureus were susceptible to all antimicrobials tested. Seven different antibiotic patterns were observed. Our results indicated that 47% and 25% of S. aureus strains exhibited resistance to penicillin and oxacillin respectively. All oxacillin-resistant isolates were mecA-positive.O presente estudo foi conduzido com o objetivo de caracterizar feno-genotipicamente os fatores de virulência e perfil de resistência aos antibióticos de Staphylococcus aureus isolados de amostras de leite de vacas com mastite clínica e subclínica. Em todos os isolados hemolíticos foi detectada a presença de beta hemolisina e 38% dos não-hemolíticos produziram hemolisinas na presença de cepa beta-hemolítica. A amplificação do gene coa apresentou quatro tipos polimórficos distintos com aproximadamente 400 bp, 600 bp, 700 bp e 900 bp. O gene spaA que codifica a região de ligação da proteína A à IgG apresentou bandas de 700 bp e 900 bp. A amplificação do gene que codifica a região X revelou um único amplicon para cada isolado sendo o tamanho prevalente o de 250pb. A amplificação do gene sae resultou em amplicons com

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

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    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.

  20. Screening and identification of bacterial strain against Staphyloccocus aureus%金黄色葡萄球菌拮抗菌株的筛选及鉴定

    Institute of Scientific and Technical Information of China (English)

    李成海; 贠建民; 艾对元; 张紊玮; 颜东方

    2013-01-01

    An antagonistic bacterial strain against foodborne pathogen Staphyloccocus aureus was isolated and screened from the drought soil of Gansu central habitat.The minimum inhibitory concentration dilute gradient of the fermentation broth and antibacterial spectrum were determined. The species of the antagonistic bacteria was identified through morphological,physiological and biochemical characteristics and 16S rDNA method.The results showed that the antagonistic bacterial strain against Staphyloccocus aureus also had antagonism against Escherichia coli, Lactobacillus plantarum and Stapyloccocush epidermidis. Its minimum inhibitory concentration dilute gradient against Staphyloccocus aureus was 10-6 and the antagonistic bacteria was Alcaligenes sp.%从甘肃中部干旱生境土壤中分离筛选到一株对食源性致病菌金黄色葡萄球菌具有抑制作用的拮抗菌,对其发酵液抑菌最低浓度稀释梯度及抑菌谱进行了测定,并通过形态学、生理生化及16S rDNA分子生物学方法鉴定了其种属.结果表明,该金黄色葡萄球菌拮抗菌株还对大肠杆菌、植物酸杆菌和表皮葡萄球菌具有抑制作用,其发酵液对金黄色葡萄球菌抑菌最低浓度稀释梯度为10-6,经鉴定,该拮抗菌为产碱杆菌属菌株Alcaligenes sp..

  1. Antimicrobial Susceptibility of Bloodstream Isolates of Staphylococcus aureus: Global Results from the Tigecycline Evaluation and Surveillance Trial, 2004-2008

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    Daniel Amsterdam

    2010-01-01

    Full Text Available Problem statement: The Tigecycline Evaluation and Surveillance Trial (TEST commenced in 2004 to monitor the activity of tigecycline, a new glycylcycline and numerous comparators against major hospital-and community-associated pathogens. In this report we examine the efficacy of tigecycline and comparators against isolates of Staphylococcus aureus collected from blood. Approach: Almost 4000 blood-derived isolates of Staphylococcus aureus were collected from participating centers globally between 2004-2008. Results: All isolates were susceptible to tigecycline (MIC90 0.25 mg L-1 and linezolid (MIC90 4 mg L-1; 99.9% of isolates were susceptible to vancomycin (MIC90 1 mg L-1. Tigecycline and linezolid activity were unaffected by resistance to methicillin, ICU vs non-ICU isolate collection or the age of patients from which the isolates were collected. Although 95.3% of MSSA were levofloxacin susceptible, only 14.4% of MRSA isolates were susceptible to levofloxacin in this study. Conclusion: Tigecycline is shown here to be active against S. aureus isolates collected from blood and is unaffected by methicillin resistance. However, tigecycline is not as yet approved for the treatment of bacteremic infections.

  2. Diversity of Virulence Factors Associated with West Australian Methicillin-Sensitive Staphylococcus aureus Isolates of Human Origin

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    Charlene Babra Waryah

    2016-01-01

    Full Text Available An extensive array of virulence factors associated with S. aureus has contributed significantly to its success as a major nosocomial pathogen in hospitals and community causing variety of infections in affected patients. Virulence factors include immune evading capsular polysaccharides, poly-N-acetyl glucosamine, and teichoic acid in addition to damaging toxins including hemolytic toxins, enterotoxins, cytotoxins, exfoliative toxin, and microbial surface components recognizing adhesive matrix molecules (MSCRAMM. In this investigation, 31 West Australian S. aureus isolates of human origin and 6 controls were analyzed for relative distribution of virulence-associated genes using PCR and/or an immunoassay kit and MSCRAMM by PCR-based typing. Genes encoding MSCRAMM, namely, Spa, ClfA, ClfB, SdrE, SdrD, IsdA, and IsdB, were detected in >90% of isolates. Gene encoding α-toxin was detected in >90% of isolates whereas genes encoding β-toxin and SEG were detectable in 50–60% of isolates. Genes encoding toxin proteins, namely, SEA, SEB, SEC, SED, SEE, SEH, SEI, SEJ, TSST, PVL, ETA, and ETB, were detectable in >50% of isolates. Use of RAPD-PCR for determining the virulence factor-based genetic relatedness among the isolates revealed five cluster groups confirming genetic diversity among the MSSA isolates, with the greatest majority of the clinical S. aureus (84% isolates clustering in group IIIa.

  3. Correlation between the VITEK2 system and cefoxitin disk diffusion for the daily detection of oxacillin resistance in a large number of clinical Staphylococcus aureus isolates.

    Science.gov (United States)

    Bemer, P; Juvin, M E; Le Gargasson, G; Drugeon, H; Reynaud, A; Corvec, S

    2010-06-01

    The aim of the present study was to compare the performance of the new VITEK2 AST-P551 card with the cefoxitin disk diffusion method for the daily detection of methicillin resistance with a high number of Staphylococcus aureus clinical isolates. Detection of the PBP2a protein or mecA gene was performed for each discordant case. Seventy (3.3%) isolates out of 2,107 clinical strains showed discordant results, two very major errors, four major errors and 64 minor errors. Fifty-nine (84%) discordant results were resolved, with a final overall agreement of 99.5%. Eleven (0.5%) strains remained discordant (minor error [mE]). Four of 370 MRSA strains were misclassified as susceptible in daily practice by the cefoxitin disk diffusion method. All of these strains were resistant to aminoglycosides and/or fluoroquinolones. The VITEK2 system is highly reliable for methicillin resistance detection at the routine level. Oxacillin-susceptible classified clinical strains with associated resistance patterns required attention.

  4. Linezolid minimum inhibitory concentration (MIC) creep in methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates at a single Japanese center.

    Science.gov (United States)

    Miyazaki, Motoyasu; Nagata, Nobuhiko; Miyazaki, Hiroyuki; Matsuo, Koichi; Takata, Tohru; Tanihara, Shinichi; Kamimura, Hidetoshi

    2014-01-01

    The aim of this study was to evaluate whether linezolid minimum inhibitory concentration (MIC) creep occurred in Staphylococcus aureus clinical isolates, including methicillin-resistant S. aureus (MRSA), over a recent 5-year period at a single Japanese center. A total of 453 MRSA and 195 methicillin-susceptible S. aureus (MSSA) isolates recovered from inpatients from April 1, 2008 to March 31, 2013 were analyzed. The MIC of linezolid was determined by automated Vitek-2 system. The modal MIC, MIC range, MIC50 and MIC90 (MICs required to inhibit the growth of 50% and 90% of organisms, respectively), geometric mean MIC and percentages of susceptible and resistant isolates were evaluated for each fiscal year. None of the S. aureus isolates were resistant to linezolid. Isolates with an MIC of >1 µg/mL were more common in the MSSA samples than in the MRSA samples (91.3% versus 38.2%, pMRSA isolates (p=0.006, r(2)=0.945 according to a linear regression analysis) over the 5-year period; however, no increase was observed in the MSSA isolates. The frequency of MRSA isolates with an MIC of 1 µg/mL decreased (from 76.3% in 2008 to 35.4% in 2012) and the isolates with MICs of >1 µg/mL increased over time (from 23.7% in 2008 to 64.6% in 2012). This report demonstrates the occurrence of linezolid MIC creep, as determined using the geometric mean MIC, in MRSA clinical isolates at a single Japanese center.

  5. Perfil fenotípico e genotípico de Staphylococcus aureus isolados de estudantes de enfermagem, 2008 Perfil fenotípico y genotípico del Staphylococcus aureus aislados de estudiantes de enfermería, 2008 Phenotypic and genotypic profile of Staphylococcus aureus isolated in nursing students, 2008

    Directory of Open Access Journals (Sweden)

    Suelen Teixeira Faria

    2011-01-01

    las muestras fueron sensibles a la vancomicina. Las muestras resistentes a la oxacilina transportaban el gen MecA.OBJECTIVE: To investigate the prevalence of nasal entrainment, phenotypic and genotypic profile of Staphylococcus aureus, asisolated from nursing students. METHODS: A cross-sectional population of 101 students enrolled in the first three grades of the undergraduate nursing course in 2008. Staphylococcus aureus was isolated from biological material obtained from the swab through the nasal vestibules. Susceptibility to oxacillin and vancomycin was determined by minimum inhibitory concentration test. The mecA gene was identified by testing the polymerase chain reaction. RESULTS: There was a 90.1% positive finding of Staphylococcus aureus. The frequency of oxacillin resistance was 9.8%; all samples were sensitive to vancomycin. The eight strains resistant to oxacillin carried the mecA gene. CONCLUSION: The prevalence of Staphylococcus aureus was high. Oxacillin resistance was significant, but all strains were sensitive to vancomycin. Isolates resistant to oxacillin carried the mecA gene.

  6. Antimicrobial drug susceptibility of Neisseria meningitidis strains isolated from carriers

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    Dayamí García

    2000-06-01

    Full Text Available When it is necessary to determine the susceptibility of Neisseria meningitidis (Nm strains to antimicrobial drugs, it is important to consider that it should be analyzed in a double context. One of them related to the use of drugs in a specific medical treatment; and the other; to chemoprophylatic drugs, both with the same purpose: the accurate selection of the “in vivo” antimicrobial agent. This requires the study of the sensitivity and resistance of strains isolated in both carriers and patients. With the aim of further studying the behavior of the strains that currently circulate in Cuba, an antimicrobial drug susceptibility study was conducted in 90 strains isolated from carriers during the first half of 1998. The agar dilution method was used to determine the minimum inhibitory concentrations (MICs to: penicillin, ampicillin, rifampin, sulfadiazine, chloramphenicol, ciprofloxacin, ceftriaxone, cefotaxime. The study of the three latter drugs was done for the first time in our country. The search for β- lactamase-producer strains was also performed. There was a predominance of penicillin sensitive strains (82,2% with an intermediate sensitivity to ampicillin (57,8%, while 70% of the strains were sensitive to sulfadiazine. Regarding the rest of the antimicrobial drugs, 100% of the strains were sensitive. The paper shows the MICs for each drug as well as the phenotypic characteristics of the strains with the penicillin and sulfadiazine sensitivity and resistance patterns. No β-lactamase-producer strains were found.

  7. Bacterial Contamination and Antibiotic Resistance of Staphylococcus Aureus Isolated from Automated Teller Machine

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    Moshtaghi, H. (PhD

    2015-05-01

    Full Text Available Background and Objective: Automated Teller Machine (ATMs is likely to be contaminated with various microorganisms specially pathogen germs. This may be due to their exposure to dust and their vast dermal contact with multiple users. This study investigated the bacterial contamination on the keyboard of ATMs and drug resistance of the bacteria isolated from them. Material and Methods: the keyboards of 50 ATMs in Shahrekord city, Iran, were examined from October 2012 to February 2013. The sterile swab sticks moistened with Triptose soy broth were used for sampling. The bacteriological tests used were culture, biochemical test and agar disk diffusion method for antibiogram. Results: All the samples were found to be contaminated with Coagulase negative staphylococci (57.54%, Bacillus species (21.92%, Staphylococcus aureus (19.18% and coliform bacteria (1.36%. The resistance of Staphylococcus aureus was 92.8% to penicillin, 85.7% to amoxicilin، 71.4% to ampicillin, 57.1% to nytrofuran, 50% to tetracycline, 42.8% to erythromycin, 42.8% to gentamycin, 14.2 % to ciprofloxacin, 7.1% to trimethoprim and sulfamtuksazul. All species were susceptible to, ofloxacine, chloramphenicol, clindamycin, tobramycin, vancomycin and cefotaxime. Conclusion: given the presence of pathogens on ATMs and their role in transferring the contamination, we recommend considering personal hygiene and periodically disinfecting the keyboards to reduce contamination

  8. Non-spa-typeable clinical Staphylococcus aureus strains are naturally occurring protein A mutants

    DEFF Research Database (Denmark)

    Baum, Cathrin; Haslinger-Löffler, Bettina; Westh, Henrik;

    2009-01-01

    Staphylococcus aureus is a major human pathogen responsible for increasing the prevalence of community- and hospital-acquired infections. Protein A (SpA) is a key virulence factor of S. aureus and is highly conserved. Sequencing of the variable-number tandem-repeat region of SpA (spa typing...

  9. Antimicrobial Activity of an Alcaligenes faecalis Strain Isolated from Oil Contaminated Soil

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    Yaghoobi Avini, M. (MSc

    2015-01-01

    Full Text Available Background and Objective: The bacteria living in the specific ecological conditions are among the most promising antimicrobial producers. This study aimed at isolating antimicrobial producing bacteria from soils contaminated with crude oil. Material and Methods: the samples were obtained from crude oil contaminated soils around Dezful located in Khuzestan province, Iran, and antimicrobial producing bacteria were isolated using disc diffusion and cross streak culture. Then, the best bacterium was selected and its antimicrobial potency was studied against indicator microorganisms. The isolate was also characterized based on biochemical properties and phylogenetic analysis. Results: based on the results, the highest antimicrobial activity of isolated bacterium was related to Candida albicans, Aspergillus niger, Bacillus subtilis, E. coli and Klebsiella pneumonia. An intermediate effect was determined against Serratia marcesens and Staphylococcus aureus, whereas no effect was observed against three strains of Enterococcus. Using biochemical characteristics and phenotypic traits, the isolate was identified as Alcaligenes faecalis. Conclusion: given that the isolate has broad spectrum activity against a various range of microorganisms and in comparison with some antimicrobial compounds produced by other Alcaligenes species, it seems the novelty of this antimicrobial compound.

  10. Isolation and characterization of cyclo-(tryptophanyl-prolyl) and chloramphenicol from Streptomyces sp. SUK 25 with antimethicillin-resistant Staphylococcus aureus activity

    Science.gov (United States)

    Alshaibani, Muhanna M; Jalil, Juriyati; Sidik, Nik M; Edrada-Ebel, Ruangelie; Zin, Noraziah M

    2016-01-01

    Background Zingiber spectabile, commonly known as Beehive Ginger, is used as an ethnobotanical plant in many countries as an appetizer or to treat stomachache, toothache, muscle sprain, and as a cure for swelling, sores and cuts. This is the first report of isolation of Streptomyces strain from the root of this plant. Strain Universiti Kebangsaan 25 (SUK 25) has a very high activity to produce secondary metabolites against methicillin-resistant Staphylococcus aureus (MRSA), which is associated with high morbidity and mortality rates due to acquired multidrug resistance genes and causes medication failure in some clinical cases worldwide. Phylogenetic analysis based on the 16S ribosomal RNA gene sequence exhibited that the most closely related strain was Streptomyces omiyaensis NBRC 13449T (99.0% similarity). Aim This study was conducted to carry out the extraction, identification, and biological evaluation of active metabolites isolated from SUK 25 against three MRSA strains, namely, MRSA ATCC 43300, MRSA ATCC 33591, and MRSA ATCC 49476. Materials and methods The production of secondary metabolites by this strain was optimized through Thronton’s media. Isolation, purification, and identification of the bioactive compounds were carried out using reversed-phase high-performance liquid chromatography, high-resolution mass spectrometry, Fourier transform infrared, and one-dimensional and two-dimensional nuclear magnetic resonance. Results During screening procedure, SUK 25 exhibited good antimicrobial potential against several strains of MRSA. The best biological activity was shown from fraction number VII and its subfractions F2 and F3 with minimum inhibitory concentration values at 16 µg/mL and 8 µg/mL, respectively. These two subfractions were identified as diketopiperazine cyclo-(tryptophanyl-prolyl) and chloramphenicol. Conclusion On the basis of obtained results, SUK 25 isolated from Z. spectabile can be regarded as a new valuable source to produce secondary

  11. Enhanced discrimination of highly clonal ST22-methicillin-resistant Staphylococcus aureus IV isolates achieved by combining spa, dru, and pulsed-field gel electrophoresis typing data.

    LENUS (Irish Health Repository)

    Shore, Anna C

    2010-05-01

    ST22-methicillin-resistant Staphylococcus aureus type IV (ST22-MRSA-IV) is endemic in Irish hospitals and is designated antibiogram-resistogram type-pulsed-field group (AR-PFG) 06-01. Isolates of this highly clonal strain exhibit limited numbers of pulsed-field gel electrophoresis (PFGE) patterns and spa types. This study investigated whether combining PFGE and spa typing with DNA sequencing of the staphylococcal cassette chromosome mec element (SCCmec)-associated direct repeat unit (dru typing) would improve isolate discrimination. A total of 173 MRSA isolates recovered in one Irish hospital during periods in 2007 and 2008 were investigated using antibiogram-resistogram (AR), PFGE, spa, dru, and SCCmec typing. Isolates representative of each of the 17 pulsed-field group 01 (PFG-01) spa types identified underwent multilocus sequence typing, and all isolates were ST22. Ninety-seven percent of isolates (168 of 173) exhibited AR-PFG 06-01 or closely related AR patterns, and 163 of these isolates harbored SCCmec type IVh. The combination of PFGE, spa, and dru typing methods significantly improved discrimination of the 168 PFG-01 isolates, yielding 65 type combinations with a Simpson\\'s index of diversity (SID) of 96.53, compared to (i) pairwise combinations of spa and dru typing, spa and PFGE typing, and dru and PFGE typing, which yielded 37, 44, and 43 type combinations with SIDs of 90.84, 91.00, and 93.57, respectively, or (ii) individual spa, dru, and PFGE typing methods, which yielded 17, 17, and 21 types with SIDs of 66.9, 77.83, and 81.34, respectively. Analysis of epidemiological information for a subset of PFG-01 isolates validated the relationships inferred using combined PFGE, spa, and dru typing data. This approach significantly enhances discrimination of ST22-MRSA-IV isolates and could be applied to epidemiological investigations of other highly clonal MRSA strains.

  12. Characterization of PVL/ACME-positive methicillin-resistant Staphylococcus aureus (genotypes ST8-MRSA-IV and ST5-MRSA-II) isolated from a university hospital in Japan.

    Science.gov (United States)

    Kawaguchiya, Mitsuyo; Urushibara, Noriko; Yamamoto, Dai; Yamashita, Toshiharu; Shinagawa, Masaaki; Watanabe, Naoki; Kobayashi, Nobumichi

    2013-02-01

    The ST8 methicillin-resistant Staphylococcus aureus (MRSA) with Staphylococcal cassette chromosome mec (SCCmec) type IVa, known as USA300, is a prevalent community-acquired MRSA (CA-MRSA) clone in the United States and has been spreading worldwide. The USA300 characteristically harbors Panton-Valentine Leukocidin (PVL) genes and the arginine catabolic mobile element (ACME, type I). Prevalence and molecular characteristics of PVL(+) and/or ACME(+) S. aureus were investigated in a university hospital located in northern Japan, for 1,366 S. aureus isolates, including 601 MRSA strains derived from clinical specimens collected from 2008 to 2010. The PVL gene was identified in three MRSA strains with SCCmec IV, which belonged to ST8, spa type t008, coagulase type III, and agr type I. Two PVL-positive MRSA strains had also type I ACME, and were isolated from skin abscess of outpatients who have not travelled abroad recently. One of these PVL(+)/ACME(+) strains carried tet(K), msrA, and aph(3')-IIIa, showing resistance to kanamycin, tetracycline, erythromycin, and ciprofloxacin, suggesting acquisition of more resistance than ST8 CA-MRSA reported in Japan previously. In contrast, another PVL(+)/ACME(+) strain and a PVL(+)/ACME(-) strain were susceptible to more antimicrobials and had less virulence factors than PVL(-)/ACME(+) MRSA strains. Besides the two PVL(+) MRSA strains, ACME (type-ΔII) was identified into seven MRSA strains with SCCmec II belonging to ST5, one of the three spa types (t002, t067, and t071), coagulase type II, and agr type II. These PVL(-)/ACME(+) MRSA strains showed multiple drug resistance and harbored various toxin genes as observed for ST5 PVL(-)/ACME(-) MRSA-II. The present study suggested the spread of ST8-MRSA-IV in northern Japan, and a potential significance of ACME-positive ST5-MRSA-II as an emerging MRSA clone in a hospital.

  13. Community-associated methicillin-resistant Staphylococcus aureus clonal complex 80 type IV (CC80-MRSA-IV isolated from the Middle East: a heterogeneous expanding clonal lineage.

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    Houda H Harastani

    Full Text Available The emergence of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA has caused a change in MRSA epidemiology worldwide. In the Middle East, the persistent spread of CA-MRSA isolates that were associated with multilocus sequence type (MLST clonal complex 80 and with staphylococcal cassette chromosome mec (SCCmec type IV (CC80-MRSA-IV, calls for novel approaches for infection control that would limit its spread.In this study, the epidemiology of CC80-MRSA-IV was investigated in Jordan and Lebanon retrospectively covering the period from 2000 to 2011. Ninety-four S. aureus isolates, 63 (67% collected from Lebanon and 31 (33% collected from Jordan were included in this study. More than half of the isolates (56% were associated with skin and soft tissue infections (SSTIs, and 73 (78% were Panton-Valentine Leukocidin (PVL positive. Majority of the isolates (84% carried the gene for exofoliative toxin d (etd, 19% had the Toxic Shock Syndrome Toxin-1 gene (tst, and seven isolates from Jordan had a rare combination being positive for both tst and PVL genes. spa typing showed the prevalence of type t044 (85% and pulsed-field gel electrophoresis (PFGE recognized 21 different patterns. Antimicrobial susceptibility testing showed the prevalence (36% of a unique resistant profile, which included resistance to streptomycin, kanamycin, and fusidic acid (SKF profile.The genetic diversity among the CC80 isolates observed in this study poses an additional challenge to infection control of CA-MRSA epidemics. CA-MRSA related to ST80 in the Middle East was distinguished in this study from the ones described in other countries. Genetic diversity observed, which may be due to mutations and differences in the antibiotic regimens between countries may have led to the development of heterogeneous strains. Hence, it is difficult to maintain "the European CA-MRSA clone" as a uniform clone and it is better to designate as CC80-MRSA-IV isolates.

  14. Antibiotic susceptibility of Staphylococcus aureus isolates in oral mucosa and pockets of patients with gingivitis-periodontitis.

    Science.gov (United States)

    Cuesta, Alicia I; Jewtuchowicz, Virginia M; Brusca, María I; Mujica, María T; Rosa, Alcira C

    2011-01-01

    Both oral cavity and subgingival pocket are ecological niches conducive to hosting microorganisms that may act as opportunistic pathogens, such as Staphylococcus aureus and especially methicillin-resistant Staphylococcus aureus (MRSA). Early detection of MRSA is a matter of concern to Public Health. The aim of our study was to determine phenotypic and genotypic detection of methicillin resistance of S. aureus in oral mucosa and subgingival pocket in 102 patients with gingivitis-periodontitis. The prevalence of S. aureus was 10.8% (n = 11) in subgingival pocket and 19.6% (n = 20) in oral mucosa. We obtained 31 isolates of S. aureus of which 13 were mecA positive and 18 were mecA negative. Detection of mecA gene by PCR was used as the reference method to compare the results of phenotypic methods to determine methicillin resistance. Early, accurate detection of S. aureus through phenotyping and genotyping methods is crucial for assessing the colonization and preventing the spread of MRSA.

  15. 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.

  16. Characteristics of Staphylococcus aureus isolated from acute, sub-acute and sub-clinical staphylococcosis in rabbits

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    Rajeshkumar J. Tirpude

    2012-12-01

    Full Text Available Staphylococcus aureus bacteria isolated from different clinical presentations of staphylococcosis in rabbits were examined for the production of various virulence factors using biochemical and immunological tests. In the total of 106 S. aureus isolates; toxic shock syndrome toxin-1, staphylococcal enterotoxin-C, DNase, α-haemolysin, β-haemolysin, δ-haemolysin, protein A and clumping factor were observed with a frequency of 33.2, 16.98, 83.96, 69.81, 36.79, 100, 78.30 and 54.72 percent, respectively. No SE-A, SE-B and SE-D producing isolates were recovered in this study. All the S. aureus isolates from acute staphylococcosis produced TSST-1, SE-C and protein A. While δ–haemolysin and clumping factor were not detected in any acute isolates, these factors were observed at a relatively higher frequency in isolates from sub-acute and sub-clinical staphylococcosis. Coagulase type III was observed more predominantly with a frequency of 45.28%, while coagulase types V and VII were not observed in any isolate. Most of the virulence factors belonged to coagulase type III followed by type VI. TSST-1 and SE-C along with coagulase types III and VI could be correlated with the acute and sub-acute staphylococcal infections in rabbits in this study.

  17. Comparative proteomics of Staphylococcus aureus and the response of methicillin-resistant and methicillin-sensitive strains to Triton X-100

    DEFF Research Database (Denmark)

    Cordwell, Stuart J; Larsen, Martin Røssel; Cole, Rebecca T;

    2002-01-01

    Proteomics is a powerful tool for analysing differences in gene expression between bacterial strains with alternate phenotypes. Staphylococcus aureus strains are grouped on the basis of their sensitivity to methicillin. Two-dimensional gel electrophoresis was combined with MS to compare the protein...... profiles of S. aureus strains COL (methicillin-resistant) and 8325 (methicillin-sensitive). Reference mapping via this approach identified 377 proteins that corresponded to 266 distinct ORFs. Amongst these identified proteins were 14 potential virulence factors. The production of 41 'hypothetical' proteins...... was confirmed, and eight of these appeared to be unique to S. aureus. Strain COL displayed 12 protein spots, which included alkaline-shock protein 23 (Asp23) and cold-shock proteins CspABC, which either were not present in strain 8325 or were present at a significantly lower intensity in this strain...

  18. Antibacterial and Antioxidant Activities of Acid and Bile Resistant Strains of Lactobacillus fermentum Isolated from Miang

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    Srikanjana Klayraung

    2009-12-01

    Full Text Available Miang is a kind of traditional fermented tea leaves, widely consumed in northern Thailand as a snack. It contains several kinds of Lactobacilli spp. The aim of this study was to isolate strains of Lactobacillus fermentum from miang and to investigate their antibacterial and antioxidant activities. The agar spot and well assays were used for determination of antibacterial power. The antibacterial mechanism was investigated by cell morphologic change under scanning electron microscope (SEM. Antioxidant activity was studied by means of free radical scavenging and ferric reducing power assays. The acid and bile screening tests indicated that L. fermentum FTL2311 and L. fermentum FTL10BR presented antibacterial activity against several pathogenic bacteria: Listeria monocytogenes DMST 17303, Salmonella Typhi DMST 5784, Shigella sonnei DMST 561 (ATCC 11060and Staphylococcus aureus subsp. aureus DMST 6512 (ATCC 6538Ptm. The results from SEM suggested that the antibacterial action was due to the destruction of cell membrane which consequently caused the pathogenic cell shrinking or cracking. The antioxidant study suggested that both L. fermentum FTL2311 and L. fermentum FTL10BR strains could liberate certain substances that possessed antioxidant activity expressed as trolox equivalent antioxidant capacity (TEAC and equivalent concentration (EC values for free radical scavenging and reducing mechanisms, respectively. The supernatant of L. fermentum FTL2311 broth revealed TEAC and EC values of 22.54±0.12 and 20.63±0.17 µM.mg-1 respectively, whereas that of L. fermentum FTL10BR yielded TEAC and EC values of 24.09±0.12 and 21.26±0.17 µM.mg-1 respectively. These two strains isolated from miang present high potential as promising health-promoting probiotics.

  19. 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...... from 105 different Danish dairy herds was investigated. A total of 85 strains (81%) proved susceptible to all of the 11 antibiotics tested, and the remaining 20 strains could be divided into 5 different antibiogram patterns. The predominant resistance pattern, penicillin resistance, was observed in 15...... (75%) of the 20 antibiotic resistant strains. Biotyping assigned the strains to 14 different types, with the most common type accounting for 25.7% of the strains. Ninety eight (93.3%) strains could be typed by phages, assigning them to 19 different phage types. The predominant phage type accounted...

  20. Immunoglobulin Fc receptors in clinical strains of Staphylococcus aureus do not confer resistance to Phagocytosis in an in vitro assay Los receptores Fc para inmunoglobulinas en cepas clínicas de Staphylococcus aureus no confieren resistencia a la fagocitosis in vitro

    Directory of Open Access Journals (Sweden)

    Benito VEGA

    1999-05-01

    Full Text Available Staphylococcus aureus binds Immunoglobulin G (IgG on its external surface due to the presence of specific receptors for the Fc domain of this immunoglobulin. This mechanism represents a kind of camouflage against phagocytic cells. In order to confirm that possibility an in vitro evaluation of the phagocytic activity of leukocytes polymorpho-nuclear (PMN against strains of Staphylococcus aureus was done, comparing 18 strains isolated from clinical samples and 16 from healthy individuals. The presence of Fc receptors was evaluated by haemagglutination (HA with erythrocytes group A after incubation of the strains with IgG anti blood group A. Phagocytosis of S. aureus was carried out by mixing live bacteria with a suspension of human PMN and incubating at 37 °C for 1 h; survivors were counted as colony forming units by plating. The strains from clinical specimens showed higher HA than those from healthy individuals (p = 0.01; but the former were killed more efficiently than the latter (80-90% and 40%, respectively. It is may be possible that S. aureus showed different behavior in vivo, where could express other virulence factors to prevent the action of phagocytes.Staphylococcus aureus liga inmunoglobulinas G (IgG a su superficie externa debido a la presencia de receptores para el dominio Fc de esas inmunoglobulinas. Este mecanismo representa una clase de camuflage contra células fagocíticas. Para confirmar tal posibilidad se realizó una evaluación in vitro de la actividad fagocítica de leucocitos polimorfonucleares (PMN contra cepas de Staphylococcus aureus, comparando 18 cepas aisladas de casos clínicos y 16 de individuos sanos. La presencia de receptores fue evaluada por hemaglutinación (HA con eritrocitos grupo A luego que las cepas fueron incubadas con IgG anti grupo sanguíneo A. La fagocitosis de S. aureus fue realizada mezclando células vivas con una suspensión de PMN e incubada a 37 °C por una hora; las bacterias sobrevivientes

  1. Indigenous strains of Lactobacillus isolated from the Istrian cheese as potential starter cultures

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    Nataša Hulak

    2016-11-01

    Full Text Available Istrian ewe’s milk cheese is an autochthonous product that is manufactured for generations on small family farms in the Croatian peninsula Istria. Traditional Istrian cheese is made from unpasteurized ewe’s milk, without the addition of starter cultures. Consequently, the specific flavour and texture of the Istrian cheese is owed to metabolic processes of indigenous microflora of which Lactobacillus species play pivotal role. Characterisation and selection of indigenous lactobacilli may result in the potential use of selected strains as starter, bioprotective or even probiotic cultures. This study focuses on potential use of Lactobacillus plantarum and Lactobacillus casei isolated from traditional Istrian cheese as starter cultures, by using methods that determine their proteolytic, lipolytic, antimicrobial and haemolytic potential, as well as their ability of acidification, autoaggregation and survival in simulated gastrointestinal conditions. Our results indicated that from 12 representative strains most revealed a low or moderate proteolytic activity as well as absence of lipolytic and haemolytic activities. From 12 strains, 5 of them showed a medium to strong acidification ability and lowered the pH of milk below 5.00 after 24 hours of incubation. Furthermore, almost all isolates exhibited antimicrobial activity against Serratia marcescens, and lowest number of isolates showed antimicrobial activity against Staphylococcus aureus and Listeria innocua. The studied Lactobacillus strains revealed high survival rate in a simulated oral cavity and duodenum conditions, while the survival ability in a simulated gastric conditions was much lower. Ability to aggregate was low for all tested strains, after 3 hours and after 5 hours of incubation.

  2. Phenotypic and genotypic antimicrobial resistance traits of foodborne Staphylococcus aureus isolates from Shanghai

    Science.gov (United States)

    Staphylococcus aureus is a recognized pathogen in humans, which causes nosocomial infections and food poisoning. The transmission of antibiotic resistant S. aureus (ARSA), especially methicillin-resistant S. aureus (MRSA), between food products and humans has become a serious problem. Hence, it is n...

  3. Detection of the intercellular adhesion gene cluster (ica in clinical Staphylococcus aureus isolates

    Directory of Open Access Journals (Sweden)

    Namvar, Amirmorteza Ebrahimzadeh

    2013-04-01

    Full Text Available [english] is a major hospital and community pathogen having the aptitude to cause a wide variety of infections in men. The ability of microorganisms to produce biofilm facilitates them to withstand the host immune response and is recognized as one factor contributing to chronic or persistent infections. It was demonstrated that the -encoded genes lead to the biosynthesis of polysaccharide intercellular adhesion (PIA molecules, and may be involved in the accumulation phase of biofilm formation. Different studies have shown the decisive role of the gene as virulence factors in staphylococcal infections. This study was carried out to demonstrate the relationship between gene and production of slime layer in strains. Sixty strains were isolated from patients. The isolates were identified morphologically and biochemically following standard laboratory methods. After identification, the staphylococcal isolates were maintained in trypticase soy broth (TSB, to which 15% glycerol was added, and stored at –20°C. Slime formation and biofilm assay was monitored. A PCR assay was developed to identify the presence of (intercellular adhesion gene gene in all isolates. Thirty-nine slime producing colonies with CRA plates (65% formed black colors, the remaining 21 isolates were pink (35%. In the quantitative biofilm assay 35 (58% produced biofilm while 25 (42% isolates did not exhibit this property. All isolates were positive for detection of gene by PCR method. The interaction of and in the investigated isolates may be important in slime layer formation and biofilm phenomena.We propose PCR detection of the gene locus as a rapid and effective method to be used for discrimination between potentially virulent and nonvirulent isolates, with implications for therapeutic and preventive measures pertainin to the management of colonized indwelling catheters.

  4. The dynamics of Staphylococcus aureus intramammary infection in nine Danish dairy herds

    DEFF Research Database (Denmark)

    Larsen, H. D.; Sloth, K. H.; Elsberg, C.

    2000-01-01

    ribo- and phage patterns identical to S. aureus isolates from human carriers. The findings of the present study underline the importance of strict milking hygiene and improvement of current mastitis therapy. The results support the hypothesis that some S. aureus mastitis strains are more contagious......The aim of the present study was to examine the diversity of Staphylococcus aureus isolates from bovine intramammary infections (IMI) in nine dairy herds, and compare these with isolates from other sites on the cows by phage- and ribotyping. Whether colonisation of milkers with S. aureus could...... be a source of infection for bovine IMI was investigated. In addition, 100 epidemiologically unrelated S. aureus isolates from asymptomatic human carriers were also phage- and ribotyped to compare the human and bovine reservoir of S. aureus in Denmark. A total of 625 S. aureus isolates from bovine IMI, bovine...

  5. [Homologous Analysis Using Repetitive-sequence-based PCR Typing of Exfoliative Toxin-producing Staphylococcus aureus Isolated from Our Hospital].

    Science.gov (United States)

    Miyamoto, Hitoshi; Murakami, Shinobu; Nishimiya, Tatsuya; Suemori, Koichiro; Tauchi, Hisamichi

    2015-05-01

    We examined staphylococcal coagulase types and homologous analysis using the DiversiLab repetitive-sequence-based PCR system in exfoliative toxin (ET)-producing Staphylococcus aureus. Twenty-two isolates (17 methicillin-sensitive Staphylococcus aureus (MSSA) and 5 methicillin-resistant Staphylococcus aureus (MRSA) isolates) obtained in our hospital from January 2012 and December 2013 were used. Three groups were classified according to the coagulase types and serotypes of ET. The first group (4 MSSA) showed coagulase type I and ET-A, and the second group (3 MSSA and 2 MRSA) showed coagulase type I and ET-B. The third group (10 MSSA and 3 MRSA) showed coagulase type V and ET-B. An analysis by DiversiLab demonstrated that homology was high in both the first and second groups. The homogenousness was high among the third group isolates except for the ocular isolates. In our hospital, three important groups were present according to a coagulase type and an ET type, and the homology of ocular isolates could be different from other materials isolates.

  6. Antimicrobial potential of Pakistani medicinal plants against multi-drug resistance Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Rahat Ejaz

    2014-09-01

    Full Text Available Objective: To determine resistance patterns of Staphylococcus aureus (S. aureus isolated from different areas of Pakistan and to identify antimicrobial agents against multi-drug resistant S. aureus strains. Methods: A total of 67 samples (sewerage, nasal and milk were collected from different farm areas of Pakistan to identify local strains of S. aureus. Sixteen out of 67 samples were positive for S. aureus. Only 6 out of 16 S. aureus strains showed resistance to antibiotics. Then the antibacterial effect of 29 medicinal plants was evaluated on these S. aureus isolates and a standard S. aureus strain ATCC 25923. The solvents used for the extraction of plants were acetone, dimethyl sulfoxide and methanol. The in vitro antibacterial activity was performed using agar disc diffusion method. Moreover, minimum inhibitory concentration of effective medicinal plant extracts was identified through micro-dilution method to find out their 50% inhibitory concentration. Results: Plant extracts of 5 medicinal plants (Psidium guajava, Nigella sativa, Piper nigrum, Valeriana jatamansi, and Cucurbita pepo exhibited antibacterial activity against locally isolated multidrug resistant strains of S. aureus. The minimum inhibitory concentration of these extracts was ranged from 0.328 to 5.000 mg/mL. Conclusions: Plant extracts of Psidium guajava, Piper nigrum seed, Valeriana jatamansi, Cucurbita pepo and Nigella sativa showed significant in vitro antibacterial activity and thus, such findings may serve as valuable contribution in the treatment of infection and may contribute to the development of potential antimicrobial agents against multi drug resistant strains of S. aureus

  7. Antimicrobial potential of Pakistani medicinal plants against multi-drug resistance Staphylococcus aureus

    Institute of Scientific and Technical Information of China (English)

    Rahat Ejaz; Usman A Ashfaq; Sobia Idrees

    2014-01-01

    Objective: To determine resistance patterns of Staphylococcus aureus (S. aureus) isolated from different areas of Pakistan and to identify antimicrobial agents against multi-drug resistant S.aureus strains. Methods: A total of 67 samples (sewerage, nasal and milk) were collected from different farm areas of Pakistan to identify local strains of S. aureus. Sixteen out of 67 samples were positive for S.aureus. Only 6 out of 16 S. aureus strains showed resistance to antibiotics. Then the antibacterial effect of 29 medicinal plants was evaluated on these S. aureus isolates and a standard S. aureus strain ATCC 25923. The solvents used for the extraction of plants were acetone, dimethyl sulfoxide and methanol. The in vitro antibacterial activity was performed using agar disc diffusion method. Moreover, minimum inhibitory concentration of effective medicinal plant extracts was identified through micro-dilution method to find out their 50% inhibitory concentration.Results:Plant extracts of 5 medicinal plants (Psidium guajava, Nigella sativa, Piper nigrum, Valeriana jatamansi, and Cucurbita pepo) exhibited antibacterial activity against locally isolated multidrug resistant strains of S. aureus. The minimum inhibitory concentration of these extracts was ranged from 0.328 to 5.000 mg/mL. Conclusions: Plant extracts of Psidium guajava, Piper nigrum seed, Valeriana jatamansi, Cucurbita pepo and Nigella sativa showed significant in vitro antibacterial activity and thus, such findings may serve as valuable contribution in the treatment of infection and may contribute to the development of potential antimicrobial agents against multi drug resistant strains of S. aureus.

  8. BIOFILM FORMATION ON THE SURFACE OF MATERIALS AND MEDICAL PRODUCTS BY NOSOCOMIAL STRAINS ISOLATED FROM THE BIOLOGICAL SUBSTRATES OF PATIENTS

    Directory of Open Access Journals (Sweden)

    E. A. Nemets

    2013-01-01

    Full Text Available Aim. To study the ability of hospital-associated strains isolated from the biological substrates of patients oper- ated on under extracorporeal circulation, to form biofilms on the surface of medical materials and products. Materials and methods. The formation of biofilms of strains of Staphylococcus aureus, Serratia liquefaciens, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter spp. isolated from the biological substrates of patients operated on under extracorporeal circulation, on different surfaces (politetraftorotilen, medical poly- ethylene, Polyoxybutirate-to-valerate, silicone, polyvinyl chloride, was studied by a modified method for the surface of the medical materials and products. Results. The influence of the material nature, as well as hydrophi- lization of the surface, on the ability of hospital-associated strains, isolated from the biological substrates of pa- tients operated on under extracorporeal circulation, to form biofilms is studied. It is shown that that certain strains exhibit an increased tendency to biofilm formation on more hydrophobic surfaces, e. g., Acinetobacter spp. At the same time the activity of Staphylococcus aureus on silicon surface (hydrophobic surface is minimal. Other strains almost equally form biofilms on hydrophilic and hydrophobic surfaces e.g. Serratia liquefaciens. It was also shown that the surface hydrophilization of PEG to 50% for all the studied strains leads to dramatic reduc- tion of biofilm formation. Conclusion. The tendency to form biofilms of a particular hospital-associated strain is individual and depends on the nature of the medical material and physical-chemical characteristics of its surface. Hydrophilization of the surface of the medical material is accompanied by a lowered risk of biofilm formation. 

  9. Frequency of the toxic shock syndrome toxin-1 gene in methicillin-susceptible and -resistant Staphylococcus aureus isolates from teaching hospitals in Shiraz, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Motamedifar

    2015-02-01

    Full Text Available INTRODUCTION: Staphylococcus aureus produces a range of virulence factors such as toxic shock syndrome toxin-1. METHODS: In this cross-sectional study of 345 clinical S. aureus isolates, the presence of the tst gene was assessed by polymerase chain reaction (PCR. RESULTS: The study revealed 53/345 (15.4% isolates were positive for the tst gene. The tst gene was present in 18.1% of methicillin-susceptible S. aureus (MSSA isolates and 11.6% of methicillin-resistant S. aureus (MRSA isolates (p = 0.136. CONCLUSIONS: These results reveal the remarkable risk of S. aureus infections in hospitals, regardless of methicillin-resistance status.

  10. The Activity of Cotinus coggygria Scop. Leaves on Staphylococcus aureus Strains in Planktonic and Biofilm Growth Forms

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    Katarína Rendeková

    2015-12-01

    Full Text Available The purpose of this study was to detect the effectiveness of Cotinus coggygria Scop. leaves methanol extract against planktonic and biofilm growth forms of Staphylococcus aureus. The antimicrobial activity was determined by the broth microdilution test. Minimal inhibitory concentrations and minimal bactericidal concentrations were detected against two collection and ten clinical S. aureus strains. Anti-biofilm activity of the tested extract was detected using 24 h bacterial biofilm on the surface of microtiter plate wells. The biofilm inhibitory activity was evaluated visually after 24 h interaction of extract with biofilm, and the eradicating activity by a regrowth method. The tested extract showed bactericidal activity against all S. aureus strains (methicillin susceptible or methicillin resistant in concentrations ranging from 0.313 to 0.625 mg·mL−1. Biofilm inhibitory concentrations were 10-times higher and biofilm eradicating concentrations 100-times higher (8 and 32 mg·mL−1, respectively. The phytochemical analysis of C. coggygria leaves 60% methanol extract performed by LC-DAD-MS/MS revealed quercetin rhamnoside, methyl gallate, and methyl trigallate as main constituents. Results of our study indicate that C. coggygria, rich in tannins and flavonoids, seems to be a prospective topical antibacterial agent with anti-biofilm activity.

  11. Study on Superantigenic Toxin Genotyping of Staphylococcus aureus Isolates from Cow Milk%牛乳金黄色葡萄球菌分离株超抗原肠毒素基因分型研究

    Institute of Scientific and Technical Information of China (English)

    孙颖; 汤婷婷; 鲍庆晗; 郭海勇; 崔京春

    2014-01-01

    To survey the enterotoxin genotypes of Staphylococcus aureus SP-3 strain isolated from the raw milk of subclinical mastitis cow,we developed specific PCR primers for five classical enterotoxin types SEA through SEE and toxin shock syndrome toxin 1 (TSST-1)type genes,as positive control with the femA and femB gene of S.aureus .The type strain (ATCC126000)and 834 strain were used as reference strains.Genomic DNA of the enterotoxigenic S.aureus were used as the template,five classical enterotox-ins and TSST-1 genes produced by S.aureus were detected by PCR amplification.The result indicated that the SP-3 isolate and the reference strains harbored femA and femB,and the SP-3 isolate from milk harbored sea,sec,sed and tst-1 superantigenic toxin genes.The study would lay a foundation for further studies on the superantigenic toxin genotyping in animal source S.aureus isolates and for preventing and controlling the infection of S.aureus in mastitis cows.%为研究牛乳金黄色葡萄球菌 SP-3分离株携带超抗原肠毒素的基因型,设计合成了金黄色葡萄球菌超抗原肠毒素基因 SEA-SEE 及 TSST-1特异性引物,并以其固有基因 femA 和 femB 为阳性对照,以分离菌株 DNA 为模板,经 PCR 扩增菌株携带的毒素基因。结果表明,SP-3分离株和阳性对照菌株均含有femA 和 femB 基因,且牛乳分离株携带 sea、sec、sed 和 tst-14种超抗原肠毒素基因,为开展动物源超抗原毒素基因系统分型及有效防控金黄色葡萄球菌奶牛乳腺炎奠定基础。

  12. Dissemination of the gene encoding exfoliative toxin of Staphylococcus intermedius among strains isolated from dogs during routine microbiological diagnostics.

    Science.gov (United States)

    Lautz, S; Kanbar, T; Alber, J; Lämmler, C; Weiss, R; Prenger-Berninghoff, E; Zschöck, M

    2006-11-01

    Phenotypic properties and species-specific PCR tests based on the nuc gene of Staphylococcus intermedius and S. aureus, and a conserved region of 16S rDNA were used to identify 45 S. intermedius and four S. aureus isolated from samples of dogs during routine diagnostics. Four S. pseudintermedius strains used for control purposes reacted positively with the S. intermedius nuc PCR showing the close relationship between both species. Investigating the 45 S. intermedius and four S. pseudintermedius strains for the prevalence of the exfoliative toxin SIET encoding gene yielded the presence of the gene for 21 of the S. intermedius and two of the S. pseudintermedius strains. Partial sequencing of the toxin gene of a single S. intermedius strain and comparing this sequence with that obtained from GenBank revealed an almost complete identity. The presence of the exfoliative toxin gene could mainly be found among S. intermedius isolated from skin and wound infections and from otitis externa possibly indicating a role of this toxin for the clinical symptoms.

  13. Genome Sequence of Borrelia garinii Strain SZ, Isolated in China

    OpenAIRE

    Wu, Qiong; Liu, Zhijie; Li, Youquan; Guan, Guiquan; Niu, Qingli; Chen, Ze; Luo, Jianxun; Yin, Hong

    2014-01-01

    We announce the genome sequence of Borrelia garinii strain SZ, isolated from Dermacentor ticks collected in northeastern China. B. garinii strain SZ carries numerous plasmids, both 10 circular and 9 linear plasmids. The 902,487-bp linear chromosome (28.2% GC content) contains 820 open reading frames, 33 tRNAs, and 4 complete rRNAs. The plasmid cp32-10 contains one clustered regularly interspaced short palindromic repeat (CRISPR) with four repeats.

  14. Isolation of five Rubrobacter strains from biodeteriorated monuments

    Science.gov (United States)

    Laiz, L.; Miller, A. Z.; Jurado, V.; Akatova, E.; Sanchez-Moral, S.; Gonzalez, J. M.; Dionísio, A.; Macedo, M. F.; Saiz-Jimenez, C.

    2009-01-01

    In the last few years, the microbial colonisation of mural paintings in ancient monuments has been attracting the attention of microbiologists and conservators. The genus Rubrobacter is commonly found in biodeteriorated monuments, where it has been reported to cause rosy discolouration. However, to date, only three species of this genus have been isolated, all from thermophilic environments. In this paper, we studied three monuments: the Servilia and Postumio tombs in the Roman Necropolis of Carmona (Spain), and Vilar de Frades church (Portugal), in search of Rubrobacter strains. In all cases, biodeterioration and the formation of efflorescences were observed, and five Rubrobacter strains were isolated. These isolates showed different physiology and migration in denaturing gradient gel electrophoresis, suggesting they might represent new species within this genus. The isolates reproduced some biodeterioration processes in the laboratory and revealed their biomediation in crystal formation.

  15. Tannic acid degradation by Klebsiella strains isolated from goat feces

    Directory of Open Access Journals (Sweden)

    Arezoo Tahmourespour

    2016-03-01

    Full Text Available Background and Objectives: Tannins are toxic polyphenols that either bind and precipitate or condense proteins. The high tannin content of some plants is the preliminary limitation of using them as a ruminant feed. So, the aim of this study was the isolation and characterization of tannic acid degrading bacterial strains from goat feces before and after feeding on Pis- tachio-Soft Hulls as tannin rich diet (TRD.Materials and Methods: Bacterial strains capable of utilizing tannic acid as sole carbon and energy source were isolated and characterized from goat feces before and after feeding on TRD. Tannase activity, maximum tolerable concentration and biodegradation potential were assessed.Results: Four tannase positive isolates were identified as Klebsiella pneumoniae. Isolated strains showed the maximum tolerable concentration of 64g/L of tannin. The tannic acid degradation percentage at a concentration of 15.0 g/L reached a maximum of 68% after 24 h incubation, and more than 98% after 72 h incubation. The pH of the medium also decreased along with tannic acid utilization.Conclusions: It is obvious that TRD induced adaptive responses. Thus, while the bacteria were able to degrade and detoxify the tannic acids, they had to adapt in the presence of high concentrations of tannic acid. So, these isolates have an amazing potential for application in bioremediation, waste water treatment, also reduction of tannins antinutritional effects in animal feeds.Keywords: Biodegradation; Goat feces; Klebsiella strains; Tannic acid

  16. Multiple-locus variable-number tandem repeat fingerprinting as a method for rapid and cost-effective typing of animal-associated Staphylococcus aureus strains from lineages other than sequence type 398.

    Science.gov (United States)

    Kosecka-Strojek, Maja; Ilczyszyn, Weronika M; Buda, Aneta; Polakowska, Klaudia; Murzyn, Krzysztof; Panz, Tomasz; Bialecka, Anna; Kasprowicz, Andrzej; Jakubczak, Antoni; Krol, Jaroslaw; Wieliczko, Alina; Wladyka, Benedykt; Miedzobrodzki, Jacek

    2016-12-01

    In veterinary medicine, Staphylococcus aureus is associated with a range of mild to severe infections. The high density of livestock in intensive farming systems increases the risk of disease spread and hampers its control and measures of prevention, making S. aureus one of the most important animal pathogens. Multiple-locus variable-number tandem repeat fingerprinting (MLVF) has been successfully applied to the characterization of livestock-associated meticillin-resistant Staphylococcus aureus (MRSA) ST398 but not to the characterization of a wide range of other animal isolates. The objective of the current study was to examine the effectiveness of MLVF for studying S. aureus strains isolated from households, farms and exotic animals in three regions of Poland. MLVF, random amplification of polymorphic DNA (RAPD), spa typing and diagnostic microarrays were compared to determine the most suitable combination of methods for veterinary purposes. MLVF generated results consistent with host and geographic origins, reflecting population structures with a high concordance to spa typing results. MLVF has been proven to be a rapid, highly discriminatory and cost-effective method suitable for molecular typing in veterinary settings.

  17. Staphylococcus aureus mevalonate kinase: isolation and characterization of an enzyme of the isoprenoid biosynthetic pathway.

    Science.gov (United States)

    Voynova, Natalya E; Rios, Sandra E; Miziorko, Henry M

    2004-01-01

    It has been proposed that isoprenoid biosynthesis in several gram-positive cocci depends on the mevalonate pathway for conversion of acetyl coenzyme A to isopentenyl diphosphate. Mevalonate kinase catalyzes a key reaction in this pathway. In this study the enzyme from Staphylococcus aureus was expressed in Escherichia coli, isolated in a highly purified form, and characterized. The overall amino acid sequence of this enzyme was very heterologous compared with the sequences of eukaryotic mevalonate kinases. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and analytical gel filtration chromatography suggested that the native enzyme is a monomer with a molecular mass of approximately 33 kDa. The specific activity was 12 U/mg, and the pH optimum was 7.0 to 8.5. The apparent K(m) values for R,S-mevalonate and ATP were 41 and 339 micro M, respectively. There was substantial substrate inhibition at millimolar levels of mevalonate. The sensitivity to feedback inhibition by farnesyl diphosphate and its sulfur-containing analog, farnesyl thiodiphosphate, was characterized. These compounds were competitive inhibitors with respect to ATP; the K(i) values were 46 and 45 micro M for farnesyl diphosphate and its thio analog, respectively. Parallel measurements with heterologous eukaryotic mevalonate kinases indicated that S. aureus mevalonate kinase is much less sensitive to feedback inhibition (K(i) difference, 3 orders of magnitude) than the human enzyme. In contrast, both enzymes tightly bound trinitrophenyl-ATP, a fluorescent substrate analog, suggesting that there are similarities in structural features that are important for catalytic function.

  18. Staphylococcus aureus isolates encode variant staphylococcal enterotoxin B proteins that are diverse in superantigenicity and lethality.

    Directory of Open Access Journals (Sweden)

    Petra L Kohler

    Full Text Available Staphylococcus aureus produces superantigens (SAgs that bind and cross-link T cells and APCs, leading to activation and proliferation of immune cells. SAgs bind to variable regions of the β-chains of T cell receptors (Vβ-TCRs, and each SAg binds a unique subset of Vβ-TCRs. This binding leads to massive cytokine production and can result in toxic shock syndrome (TSS. The most abundantly produced staphylococcal SAgs and the most common causes of staphylococcal TSS are TSS toxin-1 (TSST-1, and staphylococcal enterotoxins B and C (SEB and SEC, respectively. There are several characterized variants of humans SECs, designated SEC1-4, but only one variant of SEB has been described. Sequencing the seb genes from over 20 S. aureus isolates show there are at least five different alleles of seb, encoding forms of SEB with predicted amino acid substitutions outside of the predicted immune-cell binding regions of the SAgs. Examination of purified, variant SEBs indicates that these amino acid substitutions cause differences in proliferation of rabbit splenocytes in vitro. Additionally, the SEBs varied in lethality in a rabbit model of TSS. The SEBs were diverse in their abilities to cause proliferation of human peripheral blood mononuclear cells, and differed in their activation of subsets of T cells. A soluble, high-affinity Vβ-TCR, designed to neutralize the previously characterized variant of SEB (SEB1, was able to neutralize the variant SEBs, indicating that this high-affinity peptide may be useful in treating a variety of SEB-mediated illnesses.

  19. Phylogenetic analysis of Escherichia coli strains isolated from human samples

    Directory of Open Access Journals (Sweden)

    Abdollah Derakhshandeh

    2013-12-01

    Full Text Available Escherichia coli (E. coli is a normal inhabitant of the gastrointestinal tract of vertebrates, including humans. Phylogenetic analysis has shown that E. coli is composed of four main phylogenetic groups (A, B1, B2 and D. Group A and B1 are generally associated with commensals, whereas group B2 is associated with extra-intestinal pathotypes. Most enteropathogenic isolates, however, are assigned to group D. In the present study, a total of 102 E. coli strains, isolated from human samples, were used. Phylogenetic grouping was done based on the Clermont triplex PCR method using primers targeted at three genetic markers, chuA, yjaA and TspE4.C2. Group A contained the majority of the collected isolates (69 isolates, 67.64%, followed by group B2 (18 isolates, 17.64% and D (15 isolates, 14.7% and no strains were found to belong to group B1. The distribution of phylogenetic groups in our study suggests that although the majority of strains were commensals, the prevalence of enteropathogenic and extra-intestinal pathotypes was noteworthy. Therefore, the role of E. coli in human infections including diarrhea, urinary tract infections and meningitis should be considered.

  20. Isolation and identification of biosurfactant-producing strains from the genus Pseudomonas aeruginosa and antibacterial effects of biosurfactant production in vitro

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    Salman Ahmady-Asbchin

    2013-01-01

    Full Text Available Introduction: Biosurfactants are amphiphilic biological compounds produced extracellularly or as part of the cell membranes by a variety of microorganisms. Because of their use in various industries, they are of a particular importance. The aim of this study was to identify a strain of bacteria of the genus Pseudomonas aeruginosa biosurfactant producers. Materials and methods: In this study, different samples of oil, water and soil contaminated with oil were prepared. Hemolytic activity, emulsification activity and measurement of surface tension were used and selected strains were identified by biochemical tests. The nature and effect of antibacterial biosurfactant was evaluated for strain selection.Results: In this study, eighty eight bacterial strains were isolated. Twenty four strains were isolated from the isolated strains with hemolytic activity. Among which, 14 strains have emulsification activity more than 70% and at last four strains reached surface tension to be less than 40 mN/m. Selected strain based on biochemical tests was recognized as a Pseudomonas aeruginosa. The nature of biosurfactant was determined by TLC, and proved to be of glycolipid kind. Therefore, the produced biosurfactant of the selected strain had antibacterial activity against six bacterial infectious. Sensitive bacteria to the effects of biosurfactant extract of Pseudomonas aeruginosa83, was Staphylococcus aureus and the most resistant bacteria to these extract, was the Proteus mirabilis. The results of MIC, MBC showed that MIC of the extract in concentration of 63 and 125 mg/ml on Escherichia coli, Staphylococcus epidermidis and Staphylococcus aureus respectively. Also, the MBC were extract in concentration of 63 and 125mg/ml on Staphylococcus epidermidis and Staphylococcus aureus respectively.Discussion and conclusion: Pseudomonas aeruginosa had high potential in reducing the surface tension and biosurfactant extracted had high antibacterial effects. Therefore, it

  1. Molecular characterisation of Xanthomonas strains isolated from aroids in Mauritius.

    Science.gov (United States)

    Khoodoo, M H R; Sahin, F; Donmez, M F; Fakim, Y Jaufeerally

    2005-06-01

    Mauritius is one of the largest world producers of Anthurium cut flowers but outbreaks of bacterial blight have never been reported on the island. This work was about the characterisation and identification of bacterial strains isolated from Anthurium andreanum, Dieffenbachia maculata and Aglaonema simplex in Mauritius. Fifteen strains, that showed the morphological properties of Xanthomonas on conventional media, were tested on two semi-selective media (Esculin-trehalose and cellobiose-starch). ELISA tests using a panel of monoclonal antibodies were carried out and three out of 15 strains reacted with a Xanthomonas-specific monoclonal antibody (MAb XII). Analysis using four sets of ribosomal primers revealed that the same three Mauritius strains shared conserved PCR products with reference xanthomonads including virulent strains of Xanthomonas axonopodis pv. dieffenbachiae (Xad). BIOLOG tests and the Sherlock Microbial Identification system (MIDI) identified these three new strains at the species level as X. axonopodis. The complementary tests that were carried out clearly confirmed that the three strains are xanthomonads and, moreover, a DNA probe which showed specificity to Xad strains suggested that the three Mauritius strains are non-virulent forms of the pathogen causing Anthurium blight.

  2. Antimicrobial resistance of bacterial strains isolated from avian cellulitis

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    MM Santos

    2014-03-01

    Full Text Available Avian cellulitis is an inflammatory process in the subcutaneous tissue, mainly located in the abdomen and thighs. This problem is commonly observed in poultry at slaughter and it is considered one of the major causes of condemnation of carcasses in Brazil. The aim of this study was to perform the microbial isolation of lesions of avian cellulitis from a processing plant located in the State of Goiás in order to analyze antimicrobial resistance by antibiogram test and to detect resistance genes by polymerase chain reaction. A total of 25 samples of avian cellulitis lesions were analyzed, from which 30 bacterial strains were isolated. There were eleven (44% strains of Escherichia coli, nine (36% strains of Staphylococcus epidermidis, seven (28% strains of Proteus mirabilis and three (12% strains of Manheimiahaemolytica. The antibiogram test showed that all strains were resistant to at least one antimicrobial. The gene of antimicrobial resistance tetB was detected in E. coli, S. epidermidis and P. mirabilis strains, and was the most frequently observed gene. The gene of antimicrobial resistance Sul1 was detected in all bacterial species, while tetA was found in E. coli and S. epidermidis strains, SHV in E. coli strains, S. epidermidis and P. mirabilis,and cat1 in one P. mirabilis strain. The results suggest a potential public health hazard due to the ability of these microorganisms to transmit antimicrobial resistancegenes to other microorganisms present in the intestinal tract of humans and animals, which may affect clinical-medical usage of these drugs.

  3. Inhibition of food-related bacteria by antibacterial substances produced by Pseudomonas sp. strains isolated from pasteurized milk

    Directory of Open Access Journals (Sweden)

    Ana Beatriz Ferreira Rangel

    2013-12-01

    Full Text Available In this work, the production of antimicrobial substances by strains of Pseudomonas sp. isolated from pasteurized milk and their potential action against food-related bacteria were investigated. Samples of pasteurized milk were purchased from arbitrarily chosen commercial establishments in the city of Rio de Janeiro, Brazil. Of the four samples analyzed, three presented several typical colonies of Pseudomonas. About 100 colonies were chosen and subjected to biochemical tests for confirmation of their identity. Eighteen strains of the Pseudomonas genus were identified and submitted to tests for the production of antimicrobial substances. Twelve strains (66.7% were identified as Pseudomonas fluorescens, four (22.2% as P. aeruginosa, one (5.5% as P. mendocina and one (5.5% as P. pseudoalcaligenes. Only two P. fluorescens strains were unable to produce any antimicrobial substance against any of the indicator strains tested. Most of the strains presented a broad spectrum of action, inhibiting reference and food-related strains such as Proteus vulgaris, Proteus mirabilis, Hafnia alvei, Yersinia enterocolitica, Escherichia coli and Salmonella typhi. Five antimicrobial substance-producing strains, which presented the broadest spectrum of action, were also tested against Staphylococcus aureus reference strains and 26 Staphylococcus sp. strains isolated from foods, some of which were resistant to antibiotics. The producer strains 8.1 and 8.3, both P. aeruginosa, were able to inhibit all the staphylococcal strains tested. The antimicrobial substances produced by strains 8.1 and 8.3 did not seem to be typical bacteriocins, since they were resistant to the three proteolytic enzymes tested. Experiments involving the characterization of these substances are being carried out in order to evaluate their biotechnological application.

  4. PARAMETER KINETIKA INAKTIVASI TERMAL DAN ISOLASI Staphylococcus aureus PADA MINUMAN DARI GEL CINCAU HIJAU DAN ROSELA [Thermal Inactivation Kinetics Parameter and Isolation of Staphylococcus aureus on Drink from Green Grass Jelly and Roselle

    Directory of Open Access Journals (Sweden)

    Eko Hari Purnomo

    2015-07-01

    Full Text Available Information about heat resistance (D and z values of target bacteria is needed for the thermal process design on drink from Green Grass Jelly (Premna oblongifolia Merr. and Roselle (Hibiscus sabdariffa L., so it can guarantee quality and safety of the product. The objectives of this research were to isolate Staphylococcus aureus from commercial green grass jelly and to determine the D and z values of Staphylococcus aureus (from commercial product and standard clinical isolate ATCC 25923 on heating menstruum of green grass jelly and roselle. Isolation of S. aureus was done by inoculation in selective medium, D and z values of Staphylococcus aureus were assessed by heating at constant temperatures of 57, 53, 49, and 45°C during the time interval 2.5, 5, 10, and 15 minutes. The results showed that one isolate (Isolate A gave positive response of Staphylococcus aureus in isolation tests and had similar percentage with the reference culture of 41.8% using the API Staph Kit. Heat resistance of Staphylococcus aureus (represented as D value isolated from green grass jelly at constant heating temperature of D45, D49, D53 and D57 were 32.3, 17.9, 4.6, and 1.5 minutes. On the other hand, D value of isolates ATCC 25923 (standard clinical isolate at constant heating temperature of D45, D49, D53 and D57 were 18.5, 6.8, 2.9, and 1.4 minutes. The z value of isolates A and ATCC 25923 were 8.8°C and 10.8°C. Smaller z value of isolate A showed that pasteurization process can be accelerated and optimized with increasing the temperature slightly but has the same lethality effect.

  5. 50株食源性金黄色葡萄球菌肠毒素特性及耐药分析%Enterotoxin property and drug resistance analysis of 50 strains of food - borne Staphylococcus aureus

    Institute of Scientific and Technical Information of China (English)

    蔡雪凤; 曹宝森; 刘艳琴; 侯翠艳; 张帆; 鲁胜静

    2011-01-01

    目的:了解日常工作中分离出的食源性金黄色葡萄球菌产肠毒素特性及耐药性,为制定HACCP防止由金黄色葡萄球菌引起的食源性疾病及临床用药提供依据.方法:对分离得到的50株阳性菌株依据GB 4789.10-2010进行肠毒素A~E检验及分型;利用药敏分析仪对菌株进行药敏试验.结果:50株金黄色葡萄球菌中有20株肠毒素阳性,产肠毒素阳性率为40%,其中17株产了两种以上的毒素,有8株菌株产SEA;对氨苄西林(68%)、红霉素(56%)、克拉霉素(58%)、克林霉素(64%)、青霉素(88%)、四环素(38%)耐药率较高,并发现2株万古霉素耐药株;还发现葡萄球菌肠毒素阳性菌株对阿莫西林、苯唑西林+2%Nacl、链霉素、万古霉素耐药率较肠毒素阴性菌株高.结论:包装食品中有一定程度的金黄色葡萄球菌污染,尤其动物源性食品如冷冻食品、生肉制品等食品中较严重;食源性金黄色葡萄球菌产毒素能力较强,对肠毒素进一步分型更有实际意义;金黄色葡萄球菌对多种药物的耐药性提示安全应用治疗药物的重要性.%Objective:To understand the enterotoxin property and drug resistance of food - borne Staphylococcus aureus( S. aureus) isolated from food at daily work, and provide data for institution of HACCP, prevention of food - borne diseases caused by S. aureus and clinical drug therapy. Methods: With reference to GB 4789.10 -2010, A ~ E staphylococcal enterotoxin - preducing assay and antimicrobial susceptibility testing of 50 strains of isolated Positive strains were performed. Results: 20 strains of enterotoxin was detected in 50 S. aureus, and enterotoxin production was observed in 40%. 17 strains have more than two kinds of drug, and 8 strains have SEA; S. aureus isolates were highly resistant to ampicillin (68%), erythromycin (56%), clarithromycin (58%), clindamycin (64%), penicillin (88%), tetracycline (38%),and two strains of resistant

  6. Prevalence of the Panton-Valentine Leukocidin Gene in Clinical Isolates of Staphylococcus aureus Isolated From Hospitals the Ilam Province of Iran

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    Rostamzad

    2016-01-01

    Full Text Available Background Panton-Valentine leukocidin (luk-pv is a cytotoxin that causes leukocyte destruction and tissue necrosis. Objectives The aim of this study was to determine the prevalence of the pv1, femA, and mecA genes in staphylococcus aureus isolates from clinical specimens in hospitals in Ilam, Iran. Materials and Methods One hundred and sixty Staphylococcus aureus isolates were collected from hospitals in Ilam, Iran, and phenotypic and genotypic examinations for methicillin-resistant S. aureus (MRSA isolates were carried out. The antibiotic profiles of these isolates, and the minimal inhibitory concentration (MIC of MRSA isolates was determined using the agar dilution method with vancomycin, cefoxitin, and oxacillin. All isolates were examined using polymerase chain reaction (PCR primers for the femA, mecA, and Panton Valentine leukocidin (luk-pv genes. Results The results showed 91 isolates (56.88% were coagulase-positive, and 69 isolates (43.12% were coagulase-negative Staphylococcus aureus (CNSA. Out of 91 (56.88% coagulase-positive staphylococci, 32 isolates (35.16% were resistant to cefoxitin, and 30 isolates (32.96% were resistant to oxacillin, using disc diffusion method. PCR revealed the presence of the femA gene (510 bp band in all coagulase-positive isolates (100%, and the mecA gene (513 bp band was detected in 32 isolates (35.16%; out of 32 MRSA isolates, 13 isolates (40.62% were positive for presence of the luk-pv gene (433 bp band. Conclusions The cefoxitin disk diffusion method showed the best results when compared to oxacillin disk, similar to results from detecting the mecA gene in PCR as a golden test. Studies on MRSA that carry the luk-pv gene should continue to provide significant insight into the prevalence and epidemiology of these important resistant pathogens. Also, the rate of pvl gene-producing isolates showed to be relatively high, and it should be detected in all staphylococcal infections.

  7. Bioprotective potential of bacteriocinogenic Enterococcus gallinarum strains isolated from some Nigerian fermented foods, and of their bacteriocins.

    Science.gov (United States)

    Oladipo, Iyabo C; Sanni, Abiodun I; Writachit, Chakraborty; Chakravorty, Somnath; Jana, Sayantan; Rudra, Deep S; Gacchui, Ratan; Swarnakar, Snehasikta

    2014-01-01

    Enterococcus gallinarum strains isolated from some Nigerian fermented foods were found to produce bacteriocins. The bacteriocins had a broad spectrum of activity against both Gram-positive and negative bacteria. The effects of the bacteriocins and bacteriocinogenic organ- isms on Staphylococcus aureus infections in rats were evaluated. Sprague-Dawley rats were infected with S. aureus MTCC 737 and treated with E. gallinarum T71 and different concentrations of the bacteriocins from E. gallinarum W211 and T71. Staphylococcus aureus infection caused significant upregulation of aspartate aminotransferase and alanine aminotransferase levels in sera of the infected rats. Moreover, gelatin zymography revealed that infected gastric tissues showed elevated matrix metalloproteinase-9 activity. Bacteriocin treatments reduced the MMP-9 activity and inhibited the expressions of both Tumour Necrosis Factor Alpha (TNF-α) and Interleukin-1 Beta (IL-1β) dose dependently, pointing to a potential role of the bacteriocins in attenuating inflammatory responses to Staphylococcus aureus infec- tion. Gastric and GIT damage caused by staphylococcal infection were reduced in the Enterococcus gallinarum T71 and bacteriocin-treated groups also dose dependently. We conclude that these bacteriocins may have useful biomedical applications.

  8. Bioactivity characterization of Lactobacillus strains isolated from dairy products.

    Science.gov (United States)

    Haghshenas, Babak; Nami, Yousef; Haghshenas, Minoo; Abdullah, Norhafizah; Rosli, Rozita; Radiah, Dayang; Khosroushahi, Ahmad Yari

    2015-10-01

    This study aimed to find candidate strains of Lactobacillus isolated from sheep dairy products (yogurt and ewe colostrum) with probiotic and anticancer activity. A total of 100 samples were randomly collected from yogurt and colostrum and 125 lactic acid bacteria were isolated. Of these, 17 Lactobacillus strains belonging to five species (L. delbrueckii, L. plantarum, L. rhamnosus, L. paracasei, and L. casei) were identified. L. plantarum 17C and 13C, which isolated from colostrums, demonstrated remarkable results such as resistant to low pH and high concentrations of bile salts, susceptible to some antibiotics and good antimicrobial activity that candidate them as potential probiotics. Seven strains (1C, 5C, 12C, 13C, 17C, 7M, and 40M), the most resistant to simulated digestion, were further investigated to evaluate their capability to adhere to human intestinal Caco-2 cells. L. plantarum 17C was the most adherent strain. The bioactivity assessment of L. plantarum 17C showed anticancer effects via the induction of apoptosis on HT-29 human cancer cells and negligible side effects on one human epithelial normal cell line (FHs 74). The metabolites produced by this strain can be used as alternative pharmaceutical compounds with promising therapeutic indices because they are not cytotoxic to normal mammalian cells.

  9. Growth inhibition of Staphylococcus aureus and escherichia coli strains by neutralizing IgY antibodies from ostrich egg yolk

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    Fernando Luiz Tobias

    2012-06-01

    Full Text Available Ostrich raising around the world have some key factors and farming profit depend largely on information and ability of farmers to rear these animals. Non fertilized eggs from ostriches are discharged in the reproduction season. Staphylococcus aureus and Escherichia coli are microorganisms involved in animal and human diseases. In order to optimize the use of sub products of ostrich raising, non fertilized eggs of four selected birds were utilized for development of polyclonal IgY antibodies. The birds were immunized (200ug/animal with purified recombinant staphylococcal enterotoxin C (recSEC and synthetic recRAP, both derived from S. aureus, and recBFPA and recEspB involved in E. coli pathogenicity, diluted in FCA injected in the braquial muscle. Two subsequent immunization steps with 21 days intervals were repeated in 0,85% saline in FIA. Blood and eggs samples were collected before and after immunization steps. Egg yolk immunoglobulins were purified by precipitation with 19% sodium sulfate and 20% ammonium sulphate methodologies. Purified IgY 50µL aliquots were incubated in 850µL BHI broth containing 50µL inoculums of five strains of S. aureus and five strains of E.coli during four hours at 37ºC. Growth inhibition was evaluated followed by photometry reading (DO550nm. Egg yolk IgY preparation from hiperimmunized birds contained antibodies that inhibited significantly (p<0,05 growth of strains tested. Potential use of ostrich IgY polyclonal antibodies as a diagnostic and therapeutic tool is proposed for diseased animals.

  10. Ketamine inhibits tumor necrosis factor secretion by RAW264.7 murine macrophages stimulated with antibiotic-exposed strains of community-associated, methicillin-resistant Staphylococcus aureus

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    Aguirre Carlos

    2011-01-01

    Full Text Available Abstract Background Infections caused by community-associated strains of methicillin-resistant Staphylococcus aureus (CA-MRSA are associated with a marked and prolonged host inflammatory response. In a sepsis simulation model, we tested whether the anesthetic ketamine inhibits the macrophage TNF response to antibiotic-exposed CA-MRSA bacteria via its antagonism of N-methyl-D-aspartate (NMDA receptors. RAW264.7 cells were stimulated for 18 hrs with 105 to 107 CFU/mL inocula of either of two prototypical CA-MRSA isolates, USA300 strain LAC and USA400 strain MW2, in the presence of either vancomycin or daptomycin. One hour before bacterial stimulation, ketamine was added with or without MK-801 (dizocilpine, a chemically unrelated non-competitive NMDA receptor antagonist, APV (D-2-amino-5-phosphono-valerate, a competitive NMDA receptor antagonist, NMDA, or combinations of these agents. Supernatants were collected and assayed for TNF concentration by ELISA. Results RAW264.7 cells exposed to either LAC or MW2 in the presence of daptomycin secreted less TNF than in the presence of vancomycin. The addition of ketamine inhibited macrophage TNF secretion after stimulation with either of the CA-MRSA isolates (LAC, MW2 in the presence of either antibiotic. The NMDA inhibitors, MK-801 and APV, also suppressed macrophage TNF secretion after stimulation with either of the antibiotic-exposed CA-MRSA isolates, and the effect was not additive or synergistic with ketamine. The addition of NMDA substrate augmented TNF secretion in response to the CA-MRSA bacteria, and the addition of APV suppressed the effect of NMDA in a dose-dependent fashion. Conclusions Ketamine inhibits TNF secretion by MRSA-stimulated RAW264.7 macrophages and the mechanism likely involves NMDA receptor antagonism. These findings may have therapeutic significance in MRSA sepsis.

  11. Antibacterial activity of crude extracts of Thai medicinal plants against clinical isolates of methicillin-resistant Staphylococcus aureus

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    Kitpipit, L.

    2005-08-01

    Full Text Available Aqueous and ethanolic extracts of Acacia catechu, Garcinia mangostana, Impatiens balsamina, Peltophorum pterocarpum, Psidium guajava, Punica granatum, Quercus infectoria, Tamarindus indica, Uncaria gambir, Walsura robusta were primarily tested for their antibacterial activities against 35 clinical isolates of methicillin-resistant S. aureus and S. aureus ATCC 25923 using disc diffusion method (2.5 mg/disc. Almost all extracts, except Tamarindus indica exhibited antibacterial activity. Both aqueous and ethanolic extracts of Acacia catechu, Psidium guajava, Punica granatum, Quercus infectoria, and Uncaria gambir, and ethanolic extracts of Garcinia mangostana, Impatiens balsamina, Peltophorum pterocarpum, and Walsura robusta demonstrated inhibition zones, ranging from 6 to 22 mm. Determination of minimal inhibitory concentration (MIC and minimal bactericidal concentration (MBC values were performed using agar dilution method. The MIC/MBC values of aqueous extracts of Quercus infectoria against clinical isolates of MRSA and S. aureus were 0.2 to 0.4/0.4 to 1.6 and 0.2/1.6 mg/ ml, respectively. Ethanolic extracts of Garcinia mangostana, Punica granatum and Quercus infectoria were demonstrated to be the most effective. The MIC values against MRSA isolates and S. aureus ranged from 0.05 to 0.4 and 0.1, 0.2 to 0.4 and 0.1, 0.2 to 0.4 and 0.2 mg/ml, respectively. The MBC values against MRSA ranged from 0.1 to 0.4, 0.4 to 1.6, and 1.6 to 3.1 mg/ml and against S. aureus at 0.4, 3.2, and 1.6 mg/ml, respectively.

  12. In Vitro characterization of Lactococcus lactis strains Isolated from Iranian Traditional Dairy Products as a Potential Probiotic

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    Fatemeh Nejati

    2015-12-01

    Full Text Available Few studies have been reported regarding probiotic properties of Lactococcus lactis strains although they are extensively used as starter cultures in the production of dairy products. In this study 8 wild isolates of Lactococcus lactis were evaluated in vitro with regard to resistance to simulated gastric and intestinal juices, adherence ability to Caco-2 cells and HT29-MTX-E12 cell lines, anti-microbial activity, hydrophobicity and antibiotic susceptibility. The results revealed that all isolates had better survival after exposure to simulated gastrointestinal tract stresses in comparison to control probiotic Lactobacillus rhamnosus GG. Regarding adherence efficiency, almost all isolates exhibited similar adherence with control. Three isolates showed antibacterial activity against Gram-positive pathogens (Staphylococcus aureus and Listeria monocytogenes through spot-agar method. Almost all isolates (seven out of eight showed similar hydrophobicity to control probiotic. Regarding to antibiotic resistance, all isolates were susceptible to gentamicin, ampicillin, ciprofloxacin, erythromycin, tetracycline, penicillin, kanamycin and nitrofurantoin. Although, further investigations are necessary, it was concluded that strains derived from raw milk and home-made dairy products could be a remarkable reservoir for identification of new potential probiotic strains.

  13. Genetic Characterization of Four Strains Borrelia Burgdorferi Isolated in China

    Institute of Scientific and Technical Information of China (English)

    曾霞; 王树声; 张涛; 毕胜利; 周永东

    2004-01-01

    To study the genetic characterization of four strains of Borrelia burgdorferi isolated in China. PCR technique was used to amplify the 5S-23S rRNA intergenic spacer DNA from the whole cellular DNA of isolated GXLD-4, 9, 18 and Chang 14, and then the amplified products were cloned into plasmid pGEM-T Easy and sequenced. It was found that the 5S-23S rRNA intergenic spacer DNA of the four isolates was 242 bp, revealing the nucleotide sequence identity of more than 99%. The four isolates had higher sequence identify with Borrelia valaisiana than with other genetic groups. These four isolates most likely belong to Borrelia valaisiana genomic group.

  14. ANTIBACTERIAL ACTIVITY OF THREE PLANT EXTRACTS USED IN NIGERIA FOLKLORIC MEDICINE AGAINST HOSPITAL ISOLATES OF METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS (MRSA AND METHICILLIN-SENSITIVE STAPHYLOCOCCUS AUREUS (MSSA

    Directory of Open Access Journals (Sweden)

    Daniyan SY

    2011-03-01

    Full Text Available Staphylococcus aureus is a species of bacterium commonly found on the skin and/or in the noses of healthy people. Although it is usually harmless at these sites, it may occasionally get into the body (eg through breaks in the skin such as abrasions, cuts, wounds, surgical incisions or indwelling catheters and cause infections. These infections may be mild (eg pimples or boils or serious (eg infection of the bloodstream, bones or joints. It is one of the important bacteria as a potential pathogen specifically for nosocomial infections. Interest in plants with antimicrobial properties has revived as a result of current problems associated with the use of antibiotics.Hexane, ethylacetate, methanol and water extracts from 3 different plant species, Jatropha curcas, Piliostigma thonningii and Hyptis suaveolens used in Nigeria as popular medicine for the treatment of several ailments of microbial and non-microbial origin were evaluated for potential antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA and methicillin-sensitive Staphylococcus aureus (MSSA using agar dilution method. Results revealed that there were no significant differences in the % susceptibility to MRSA and MSSA between the standard drugs and the different plant extracts using different extracting solvents (P>0.05. All the extracts of the 3 plants were effective on MRSA except water extract of Jatropha curcas and Piliostigma thonningii. Hexane extract from P. thonningii was inhibitory to 100% of both MRSA and MSSA isolates followed by ethyl acetate extract of J. curcas 61% of MSSA, ethyl acetate extract of P. thonningii on 38% of MRSA, methanol extract of J. curcas on 33% of both MSSA and MRSA and the least activity was with water extract of H. suaveolens on 17% of both MSSA and MRSA; no activity was observed with water extract of J. curcas. Hexane extract of P.thonningii was the only extract found in this study to inhibit the growth of both MRSA and MSSA

  15. Variation in Extracellular Protease Production among Clinical Isolates of Staphylococcus aureus Due to Different Levels of Expression of the Protease Repressor sarA

    OpenAIRE

    Karlsson, Anna; Arvidson, Staffan

    2002-01-01

    Staphylococcus aureus produces four major extracellular proteases: staphylococcal serine protease (V8 protease; SspA), cysteine protease (SspB), metalloprotease (aureolysin; Aur), and staphopain (Scp). Several in vitro studies have suggested that these enzymes are important virulence factors. Here we analyzed the protease production of 92 S. aureus strains from infected human soft tissue. Twenty-one strains produced variable zones of proteolysis on casein agar plates, while the remaining 71 s...

  16. Isolation and Host Range of Bacteriophage with Lytic Activity against Methicillin-Resistant Staphylococcus aureus and Potential Use as a Fomite Decontaminant.

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    Kyle C Jensen

    Full Text Available Staphylococcus aureus (SA is a commensal bacterium and opportunistic pathogen commonly associated with humans and is capable of causing serious disease and death including sepsis, pneumonia, and meningitis. Methicillin-resistant SA (MRSA isolates are typically resistant to many available antibiotics with the common exception of vancomycin. The presence of vancomycin resistance in some SA isolates combined with the current heavy use of vancomycin to treat MRSA infections indicates that MRSA may achieve broad resistance to vancomycin in the near future. New MRSA treatments are clearly needed. Bacteriophages (phages are viruses that infect bacteria, commonly resulting in death of the host bacterial cell. Phage therapy entails the use of phage to treat or prevent bacterial infections. In this study, 12 phages were isolated that can replicate in human SA and/or MRSA isolates as a potential way to control these infections. 5 phage were discovered through mitomycin C induction of prophage and 7 others as extracellular viruses. Primary SA strains were also isolated from environmental sources to be used as tools for phage discovery and isolation as well as to examine the target cell host range of the phage isolates by spot testing. Primary isolates were tested for susceptibility to oxacillin in order to determine which were MRSA. Experiments were performed to assess the host range and killing potential of newly discovered phage, and significant reductions in bacterial load were detected. We explored the utility of some phage to decontaminate fomites (glass and cloth and found a significant reduction in colony forming units of MRSA following phage treatment, including tests of a phage cocktail against a cocktail of MRSA isolates. Our findings suggest that phage treatment can be used as an effective tool to decontaminate human MRSA from both hard surfaces and fabrics.

  17. Detection of mecA- and mecC-Positive Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates by the New Xpert MRSA Gen 3 PCR Assay

    OpenAIRE

    Becker, Karsten; Denis, Olivier; Roisin, Sandrine; Mellmann, Alexander; Evgeny A Idelevich; Knaack, Dennis; van Alen, Sarah; Kriegeskorte, André; Köck, Robin; Schaumburg, Frieder; Peters, Georg; Ballhausen, Britta

    2015-01-01

    An advanced methicillin-resistant Staphylococcus aureus (MRSA) detection PCR approach targeting SCCmec-orfX along with mecA and mecC was evaluated for S. aureus and coagulase-negative staphylococci. The possession of mecA and/or mecC was correctly confirmed in all cases. All methicillin-susceptible S. aureus strains (n = 98; including staphylococcal cassette chromosome mec element [SCCmec] remnants) and 98.1% of the MRSA strains (n = 160, including 10 mecC-positive MRSA) were accurately categ...

  18. Clonally related methicillin-resistant Staphylococcus aureus isolated from short-finned pilot whales (Globicephala macrorhynchus), human volunteers, and a bayfront cetacean rehabilitation facility.

    Science.gov (United States)

    Hower, Suzanne; Phillips, Matthew C; Brodsky, Micah; Dameron, Adrienne; Tamargo, Manuel A; Salazar, Norma C; Jackson, Charlene R; Barrett, John B; Davidson, Maureen; Davis, Johnnie; Mukherjee, Sampa; Ewing, Ruth Y; Gidley, Maribeth L; Sinigalliano, Christopher D; Johns, Lisa; Johnson, Frank E; Adebanjo, Olufunmilola; Plano, Lisa R W

    2013-05-01

    In May of 2011, a live mass stranding of 26 short-finned pilot whales (Globicephala macrorhynchus) occurred in the lower Florida Keys. Five surviving whales were transferred from the original stranding site to a nearby marine mammal rehabilitation facility where they were constantly attended to by a team of volunteers. Bacteria cultured during the routine clinical care of the whales and necropsy of a deceased whale included methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA). In order to investigate potential sources or reservoirs of MSSA and MRSA, samples were obtained from human volunteers, whales, seawater, and sand from multiple sites at the facility, nearby recreational beaches, and a canal. Samples were collected on 3 days. The second collection day was 2 weeks after the first, and the third collection day was 2 months after the last animal was removed from the facility. MRSA and MSSA were isolated on each day from the facility when animals and volunteers were present. MSSA was found at an adjacent beach on all three collection days. Isolates were characterized by utilizing a combination of quantitative real-time PCR to determine the presence of mecA and genes associated with virulence, staphylococcal protein A typing, staphylococcal cassette chromosome mec typing, multilocus sequence typing, and pulsed field gel electrophoresis (PFGE). Using these methods, clonally related MRSA were isolated from multiple environmental locations as well as from humans and animals. Non-identical but genetically similar MSSA and MRSA were also identified from distinct sources within this sample pool. PFGE indicated that the majority of MRSA isolates were clonally related to the prototype human strain USA300. These studies support the notion that S. aureus may be shed into an environment by humans or pilot whales and subsequently colonize or infect exposed new hosts.

  19. The Evaluation of the Distribution and Antimcrobial Susceptibility Profile of the Strains Isolated at Anesthesiology Intensive Care Unit

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    Gulfem Ece

    2013-10-01

    Full Text Available Aim: Hospital infections are important uptodate health problems because of high mortality and increased cost. The increment in antimicrobial resistance is progressing though new antimicrobial agents are arising. This leads to an increase in hospital infections and difficulty in treatment. In our study we aimed to evaluate the antimicrobial susceptibility of the strains isolated at Anesthesiology Intensive Care Unit. Material and Method: The antimicrobial susceptibility of the strains isolated at Anesthesiology Intensive Care Unit between April 1st 2012- October 25th 2012 were included. The identification and the antimicrobial susceptibility were studied by automatized Vitek version 2.0 (Biomerieux, France. Results: A total of 155 strains isolated from wound, blood, tracheal secretion, sputum and urine samples were included. They are consisted of 40 A. baumannii, 24 E.coli, 25 P. aeruginosa, 20 K.pneumoniae, 12 Methicilin Resistant Coagulase Negative Staphylococci (MRCoNS, nine Methiciline Susceptible S.aureus (MSSA, eight C.albicans, four Methicilin Resistant S.aureus (MRSA, one C.famata, one C.tropicalis, three E.faecalis, two E.faecium, three S.marsecens, two P. mirabilis and one H.influenzae. Clinical samples were 81 tracheal secretions, 25 wound specimen, 23 blood culture, 18 urine, seven sputum, and one BAL. All the Gram positive strains were susceptible to glycopeptides. Enterobacteriaceae members were susceptible to imipenem and meropenem. Discussion: Antimicrobial resistance is an important issue worldwide. Multidiciplinary approach is needed as in ICUs where the complicated patients are followed. Monitoring antibiotic resistance profile contributes to treatment and decreasing resistance rates. The resistance profile will guide the antibiotic use policy. Increment in number of isolates in future will help to obtain the antimicrobial resistance profile.

  20. Susceptibility of Staphylococcus aureus isolates to vancomycin at a university hospital in southern Brazil Suscetibilidade de amostras de Staphylococcus aureus à vancomicina isoladas em um hospital universitário no sul do Brasil

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    Larissa Lutz

    2006-09-01

    Full Text Available The in vitro susceptibilty of Staphylococcus aureus to vancomycin was evaluated from impatients at a Brazilian University Hospital by the Etest and a screening method. No vancomycin intermediate (VISA or vancomycin resistant (VRSA S. aureus isolate was identified. Three patients presented as heteroresistant VISA (h-VISA isolates but none of them received vancomycin previously.A suscetibilidade in vitro de Staphylococcus aureus à vancomicina foi avaliada em pacientes internados em um Hospital Universitário Brasileiro pelo Etest e por um método de triagem. Nenhuma amostra de S. aureus resistente (VRSA ou com resistência intermediária (VISA à vancomicina foi isolada. Três pacientes tiveram amostras heteroresistentes VISA (h-VISA, mas nenhum destes recebeu vancomicina previamente.

  1. Antimicrobial resistance in Enterococcus strains isolated from healthy domestic dogs.

    Science.gov (United States)

    Bertelloni, Fabrizio; Salvadori, Claudia; Lotti, Giulia; Cerri, Domenico; Ebani, Valentina Virginia

    2016-12-15

    Enterococci are opportunistic bacteria that cause severe infections in animals and humans, capable to acquire, express, and transfer antimicrobial resistance. Susceptibility to 21 antimicrobial agents was tested by the disk diffusion method in 222 Enterococcus spp. strains isolated from the fecal samples of 287 healthy domestic dogs. Vancomycin and ampicillin minimum inhibitory concentrations (MICs) and high-level aminoglycoside resistance (HLAR) tests were also performed. Isolates showed resistance mainly to streptomycin (88.7%), neomycin (80.6%), and tetracycline (69.4%). Forty-two (18.9%) isolates showed an HLAR to streptomycin and 15 (6.7%) to gentamicin. Vancomycin and ampicillin MIC values showed 1 and 18 resistant strains, respectively. One hundred and thirty-six (61.2%) strains were classified as multidrug resistant and six (2.7%) strains as possibly extensively drug-resistant bacteria. Enterococcus faecium and Enterococcus faecalis were the most prevalent antimicrobial resistant species. Companion animals, which often live in close contact with their owners and share the same environment, represent a serious source of enterococci resistant to several antibiotics; for this reason, they may be a hazard for public health by providing a conduit for the entrance of resistance genes into the community.

  2. Old Drugs To Treat Resistant Bugs: Methicillin-Resistant Staphylococcus aureus Isolates with mecC Are Susceptible to a Combination of Penicillin and Clavulanic Acid.

    Science.gov (United States)

    Ba, Xiaoliang; Harrison, Ewan M; Lovering, Andrew L; Gleadall, Nicholas; Zadoks, Ruth; Parkhill, Julian; Peacock, Sharon J; Holden, Matthew T G; Paterson, Gavin K; Holmes, Mark A

    2015-12-01

    β-Lactam resistance in methicillin-resistant Staphylococcus aureus (MRSA) is mediated by the expression of an alternative penicillin-binding protein 2a (PBP2a) (encoded by mecA) with a low affinity for β-lactam antibiotics. Recently, a novel variant of mecA, known as mecC, was identified in MRSA isolates from both humans and animals. In this study, we demonstrate that mecC-encoded PBP2c does not mediate resistance to penicillin. Rather, broad-spectrum β-lactam resistance in MRSA strains carrying mecC (mecC-MRSA strains) is mediated by a combination of both PBP2c and the distinct β-lactamase encoded by the blaZ gene of strain LGA251 (blaZLGA251), which is part of mecC-encoding staphylococcal cassette chromosome mec (SCCmec) type XI. We further demonstrate that mecC-MRSA strains are susceptible to the combination of penicillin and the β-lactam inhibitor clavulanic acid in vitro and that the same combination is effective in vivo for the treatment of experimental mecC-MRSA infection in wax moth larvae. Thus, we demonstrate how the distinct biological differences between mecA- and mecC-encoded PBP2a and PBP2c have the potential to be exploited as a novel approach for the treatment of mecC-MRSA infections.

  3. Identification of Secreted Exoproteome Fingerprints of Highly-Virulent and Non-Virulent Staphylococcus aureus Strains

    NARCIS (Netherlands)

    Bonar, Emilia; Wojcik, Iwona; Jankowska, Urszula; Kedracka-Krok, Sylwia; Bukowski, Michal; Polakowska, Klaudia; Lis, Marcin W; Kosecka-Strojek, Maja; Sabat, Artur J; Dubin, Grzegorz; Friedrich, Alexander W; Miedzobrodzki, Jacek; Dubin, Adam; Wladyka, Benedykt

    2016-01-01

    Staphylococcus aureus is a commensal inhabitant of skin and mucous membranes in nose vestibule but also an important opportunistic pathogen of humans and livestock. The extracellular proteome as a whole constitutes its major virulence determinant; however, the involvement of particular proteins is s

  4. Antibacterial activity of three newly-synthesized chalcones & synergism with antibiotics against clinical isolates of methicillin-resistant Staphylococcus aureus

    OpenAIRE

    2014-01-01

    Background & objectives: Multidrug-resistance of methicillin-resistant Staphylococcus aureus (MRSA) is a serious therapeutical problem. Chalcones belong to a group of naturally occurring flavonoids, usually found in various plant species, and have potent antibacterial, antiviral and antifungal activities. The goal of this study was to evaluate the antibacterial effect of three newly-synthesized chalcones against clinical isolates of MRSA, and their synergism with β-lactam and non- β-lactam an...

  5. An international multicenter study of antimicrobial consumption and resistance in Staphylococcus aureus isolates from 15 hospitals in 14 countries

    DEFF Research Database (Denmark)

    Westh, Henrik Torkil; Zinn, Christina Scheel; Rosdahl, Vibeke Thamdrup

    2004-01-01

    Antibiotic consumption during 1996 was measured in 15 large hospitals from 14 countries and 3000 consecutive Staphylococcus aureus samples were collected, allowing calculation of local resistance rates and typing of isolates. Antibiotic consumption data were converted to defined daily doses (DDD...... to consumption of aminoglycosides, quinolones, and glycopeptides. In this study of hospitals with MRSA prevalence of between 0% and 63%, significant correlations were found between resistance and consumption of antimicrobials. These findings support the importance of antimicrobial consumption on resistance...

  6. Effects of ceftobiprole and oxacillin on mecA expression in methicillin-resistant Staphylococcus aureus clinical isolates.

    Science.gov (United States)

    Shang, Wenchi; Davies, Todd A; Flamm, Robert K; Bush, Karen

    2010-02-01

    Induction of mecA by ceftobiprole and oxacillin in 18 methicilli