Full Text Available Abstract Introduction Certain Staphylococcus aureus strains produce Panton-Valentine leukocidin, a toxin that lyses white blood cells causing extensive tissue necrosis and chronic, recurrent or severe infection. This report documents a confirmed case of methicillin-sensitive Staphylococcus aureus strain harboring Panton-Valentine leukocidin genes from Trinidad and Tobago. To the best of our knowledge, this is the first time that such a case has been identified and reported from this country. Case presentation A 13-year-old Trinidadian boy of African descent presented with upper respiratory symptoms and gastroenteritis-like syptoms. About two weeks later he was re-admitted to our hospital complaining of pain and weakness affecting his left leg, where he had received an intramuscular injection of an anti-emetic drug. He deteriorated and developed septic arthritis, necrotizing fasciitis and septic shock with acute respiratory distress syndrome, leading to death within 48 hours of admission despite intensive care treatment. The infection was caused by S. aureus. Bacterial isolates from specimens recovered from our patient before and after his death were analyzed using microarray DNA analysis and spa typing, and the results revealed that the S. aureus isolates belonged to clonal complex 8, were methicillin-susceptible and positive for Panton-Valentine leukocidin. An autopsy revealed multi-organ failure and histological tissue stains of several organs were also performed and showed involvement of his lungs, liver, kidneys and thymus, which showed Hassal's corpuscles. Conclusion Rapid identification of Panton-Valentine leukocidin in methicillin-sensitive S. aureus isolates causing severe infections is necessary so as not to miss their potentially devastating consequences. Early feedback from the clinical laboratories is crucial.
Panton-Valentine leukocidin (PVL)-producing Staphylococcus aureus results in leukocyte destruction and tissue necrosis (Pediatric Dermatology 2007;24:401). It can be associated with a spectrum of clinical manifestations that range from localized staphylococcal skin infections to sometimes severe necrotizing pneumonia (Clin Infect Dis 1999;29:1128). We report a case of four siblings, three brothers whose atopic dermatitis was complicated by cutaneous lesions and furunculosis, while their 21-month-old sister had a fatal PVL positive staphylococcal pneumonia.
Deurenberg, Ruud H; Vink, Cornelis; Driessen, Christel; Bes, Michèle; London, Nancy; Etienne, Jerome; Stobberingh, Ellen E
To allow rapid identification of Panton-Valentine leukocidin (PVL)-producing Staphylococcus aureus strains, a real-time PCR assay for detection of PVL was developed. This assay is convenient, since it can be applied directly on bacterial suspensions and does not require previous DNA purification.
Laverdure, F; Neulier, C; Sudant, J; Legriel, S; Bruneel, F
Panton-Valentine leukocidin-producing Staphylococcus aureus necrotizing pneumonia is an unusual cause of community-acquired pneumonia associated with a high fatality rate. The specificities of its presentation must be known by the critical care doctor, in order to quickly make the diagnosis and start the right antibiotics and discuss adjunctive therapy with intravenous immunoglobin. Moreover, the management of close contacts (household and healthcare workers) of patient with such a pneumonia is not well-known. The present case report underlines the clinical presentation of this pneumonia, the specificities of its treatment, and specifies the management of close contacts. Copyright © 2014 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier SAS. All rights reserved.
Ching Wen Tseng
Full Text Available Staphylococcus aureus is a leading cause of skin and soft-tissue infections worldwide. Mice are the most commonly used animals for modeling human staphylococcal infections. However a supra-physiologic S. aureus inoculum is required to establish gross murine skin pathology. Moreover, many staphylococcal factors, including Panton-Valentine leukocidin (PVL elaborated by community-associated methicillin-resistant S. aureus (CA-MRSA, exhibit selective human tropism and cannot be adequately studied in mice. To overcome these deficiencies, we investigated S. aureus infection in non-obese diabetic (NOD/severe combined immune deficiency (SCID/IL2rγnull (NSG mice engrafted with human CD34+ umbilical cord blood cells. These "humanized" NSG mice require one to two log lower inoculum to induce consistent skin lesions compared with control mice, and exhibit larger cutaneous lesions upon infection with PVL+ versus isogenic PVL- S. aureus. Neutrophils appear important for PVL pathology as adoptive transfer of human neutrophils alone to NSG mice was sufficient to induce dermonecrosis following challenge with PVL+ S. aureus but not PVL- S. aureus. PMX53, a human C5aR inhibitor, blocked PVL-induced cellular cytotoxicity in vitro and reduced the size difference of lesions induced by the PVL+ and PVL- S. aureus, but PMX53 also reduced recruitment of neutrophils and exacerbated the infection. Overall, our findings establish humanized mice as an important translational tool for the study of S. aureus infection and provide strong evidence that PVL is a human virulence factor.
Binh An Diep
Full Text Available Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA strains typically carry genes encoding Panton-Valentine leukocidin (PVL. We used wild-type parental and isogenic PVL-deletion (Delta pvl strains of USA300 (LAC and SF8300 and USA400 (MW2 to test whether PVL alters global gene regulatory networks and contributes to pathogenesis of bacteremia, a hallmark feature of invasive staphylococcal disease. Microarray and proteomic analyses revealed that PVL does not alter gene or protein expression, thereby demonstrating that any contribution of PVL to CA-MRSA pathogenesis is not mediated through interference of global gene regulatory networks. Inasmuch as a direct role for PVL in CA-MRSA pathogenesis remains to be determined, we developed a rabbit bacteremia model of CA-MRSA infection to evaluate the effects of PVL. Following experimental infection of rabbits, an animal species whose granulocytes are more sensitive to the effects of PVL compared with the mouse, we found a contribution of PVL to pathogenesis over the time course of bacteremia. At 24 and 48 hours post infection, PVL appears to play a modest, but measurable role in pathogenesis during the early stages of bacteremic seeding of the kidney, the target organ from which bacteria were not cleared. However, the early survival advantage of this USA300 strain conferred by PVL was lost by 72 hours post infection. These data are consistent with the clinical presentation of rapid-onset, fulminant infection that has been associated with PVL-positive CA-MRSA strains. Taken together, our data indicate a modest and transient positive effect of PVL in the acute phase of bacteremia, thereby providing evidence that PVL contributes to CA-MRSA pathogenesis.
Low, T B
We report a case of a 15-year-old boy who developed multiple organ failure secondary to a sport injury leading to infection with a Panton Valentine Leukocidin (PVL) secreting Community-Acquired Methicillin Sensitive Staphylococcus Aureus (CA MSSA). Aggressive antibiotic therapy eventually led to recovery.
Leistner, Rasmus; Kola, Axel; Gastmeier, Petra; Krüger, Renate; Hoppe, Pia-Alice; Schneider-Burrus, Sylke; Zuschneid, Irina; Wischnewski, Nicoletta; Bender, Jennifer; Layer, Franziska; Niebank, Michaela; Scheibenbogen, Carmen; Hanitsch, Leif G
We report on an outbreak of skin and soft tissue infections (SSTI) among kindergarten families. We analyzed the transmission route and aimed to control the outbreak. The transmission route was investigated by nasal screening for Panton-Valentine leukocidin (PVL)-producing Staphylococcus aureus (PVL-SA), subsequent microbiological investigation including whole genome sequencing and a questionnaire-based analysis of epidemiological information. The control measures included distribution of outbreak information to all individuals at risk and implementation of a Staphylococcus aureus decontamination protocol. Individuals from 7 of 19 families were either colonized or showed signs of SSTI such as massive abscesses or eye lid infections. We found 10 PVL-SA isolates in 9 individuals. In the WGS-analysis all isolates were found identical with a maximum of 17 allele difference. The clones were methicillin-susceptible but cotrimoxazole resistant. In comparison to PVL-SAs from an international strain collection, the outbreak clone showed close genetical relatedness to PVL-SAs from a non-European country. The questionnaire results showed frequent travels of one family to this area. The results also demonstrated likely transmission via direct contact between families. After initiation of Staphylococcus aureus decontamination no further case was detected. Our outbreak investigation showed the introduction of a PVL-SA strain into a kindergarten likely as a result of international travel and further transmission by direct contact. The implementation of a Staphylococcus aureus decontamination protocol was able to control the outbreak.
Full Text Available We report on an outbreak of skin and soft tissue infections (SSTI among kindergarten families. We analyzed the transmission route and aimed to control the outbreak.The transmission route was investigated by nasal screening for Panton-Valentine leukocidin (PVL-producing Staphylococcus aureus (PVL-SA, subsequent microbiological investigation including whole genome sequencing and a questionnaire-based analysis of epidemiological information. The control measures included distribution of outbreak information to all individuals at risk and implementation of a Staphylococcus aureus decontamination protocol.Individuals from 7 of 19 families were either colonized or showed signs of SSTI such as massive abscesses or eye lid infections. We found 10 PVL-SA isolates in 9 individuals. In the WGS-analysis all isolates were found identical with a maximum of 17 allele difference. The clones were methicillin-susceptible but cotrimoxazole resistant. In comparison to PVL-SAs from an international strain collection, the outbreak clone showed close genetical relatedness to PVL-SAs from a non-European country. The questionnaire results showed frequent travels of one family to this area. The results also demonstrated likely transmission via direct contact between families. After initiation of Staphylococcus aureus decontamination no further case was detected.Our outbreak investigation showed the introduction of a PVL-SA strain into a kindergarten likely as a result of international travel and further transmission by direct contact. The implementation of a Staphylococcus aureus decontamination protocol was able to control the outbreak.
Rimoldi, Sara Giordana; Pagani, Cristina; Longhi, Erika; Di Cristo, Valentina; Di Gregorio, Annamaria; Mancon, Alessandro; Zerbi, Pietro; Gervasoni, Cristina; Gismondo, Maria Rita; Riva, Agostino
One of the most important Staphylococcus aureus virulence factors is Panton-Valentine leukocidin (PVL). We describe an outbreak of recurrent cutaneous PVL infections in different members of three family clusters. Molecular investigations were performed to confirm the presence of the mecA and PVL genes and to assign the SCCmec type, sequence type (ST) and clonal relatedness. A strain of PVL-producing methicillin-resistant S. aureus (MRSA) was responsible for infection in two related families (A and B), and a third family (C) was infected with PVL-producing methicillin-sensitive S. aureus (MSSA). Molecular investigations revealed the same clone of community-acquired (CA)-MRSA, PVL positive ST8, and SCCmec IV in families A and B and CA-MSSA PVL positive ST15 in family C. S. aureus PVL may give rise to recurrent uncontrolled infections that are difficult to eradicate, and close family contacts are at high risk for transmission. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Full Text Available Despite epidemiological data linking necrotizing skin infections with the production of Panton-Valentine leukocidin (PVL, the contribution of this toxin to the virulence of S. aureus has been highly discussed as a result of inconclusive results of in vivo studies. However, the majority of these results originate from experiments using mice, an animal species which neutrophils--the major target cells for PVL--are highly insensitive to the action of this leukocidin. In contrast, the rabbit neutrophils have been shown to be as sensitive to PVL action as human cells, making the rabbit a better experimental animal to explore the PVL role. In this study we examined whether PVL contributes to S. aureus pathogenicity by means of a rabbit skin infection model. The rabbits were injected intradermally with 10(8 cfu of either a PVL positive community-associated methicillin-resistant S. aureus isolate, its isogenic PVL knockout or a PVL complemented knockout strain, and the development of skin lesions was observed. While all strains induced skin infection, the wild type strain produced larger lesions and a higher degree of skin necrosis compared to the PVL knockout strain in the first week after the infection. The PVL expression in the rabbits was indirectly confirmed by a raise in the serum titer of anti-LukS-PV antibodies observed only in the rabbits infected with PVL positive strains. These results indicate that the rabbit model is more suitable for studying the role of PVL in staphylococcal diseases than other animal models. Further, they support the epidemiological link between PVL producing S. aureus strains and necrotizing skin infections.
Mohd-Zain, Z; Mohd-Nawi, S F A; Adnan, A; Kumar, S
HIV-infected patients pose a high risk of contracting skin and soft tissue infections caused by Staphylococcus aureus. Those who are colonized with methicillin-resistant S. aureus (MRSA) that carry Panton-Valentine leukocidin (PVL) are predisposed to severe infections that could lead to necrotic skin infections. However the association of S. aureus specifically methicillin sensitive S. aureus carrying PVL gene in HIV patients has not been widely reported. Here, we study the prevalence and the molecular epidemiology of PVL-producing S. aureus in HIV-infected patients. Swabs from four body sites of 129 HIV-infected patients were cultured for S. aureus and identified by standard microbiological procedures. The isolates were subjected to antimicrobial susceptibility testing by disk diffusion against penicillin, erythromycin, clindamycin, and cotrimoxazole. PCR was used to detect the PVL gene and genetic relationship between the isolates was determined by using pulse field gel electrophoresis. A total of 51 isolates of S. aureus were obtained from 40 (31%) of the patients. The majority (43.1%) of the isolates were obtained from the anterior nares. Thirteen (25.5%) of all the isolates were resistant to more than one category of antibiotics, with one isolate identified as MRSA. Thirty-eight (74.5%) isolates (including the MRSA isolate) carried PVL gene where the majority (44.7%) of these isolates were from the anterior nares. A dendogram revealed that the isolates were genetically diverse with 37 distinct pulsotypes clustered in 11 groups. S. aureus obtained from multiple sites of the HIV patients were genetically diverse without any clonality observed.
Full Text Available Patients infected with the human immunodeficiency virus (HIV are frequently exposed to antimicrobial agents. This might have an impact on the resistance profile, genetic background and virulence factors of colonizing Staphylococcus aureus. Sub-Saharan Africa is considered to be endemic for Panton-Valentine leukocidin (PVL positive S. aureus which can be associated with skin and soft tissue infections. We compared S. aureus from nasal and pharyngeal swabs from HIV patients (n=141 and healthy controls (n=206 in Gabon in 2013, and analyzed determinants of colonization with PVL positive isolates in a cross-sectional study. S. aureus isolates were screened for the presence of selected virulence factors (incl. PVL and were subjected to antimicrobial susceptibility testing and genotyping. In HIV patients, S. aureus was more frequently detected (36.9 vs. 31.6% and the isolates were more frequently PVL positive than in healthy controls (42.1 vs. 23.2%. The presence of PVL was associated with cotrimoxazole resistance (OR=25.1, p<0.001 and the use of cotrimoxazole was a risk factor for colonization with PVL positive isolates (OR=2.5, p=0.06. PVL positive isolates were associated with the multilocus sequence types ST15 (OR=5.6, p<0.001 and ST152 (OR=62.1, p<0.001.Participants colonized with PVL positive isolates reported more frequently skin and soft tissue infection (SSTI in the past compared to carriers of PVL negative isolates (OR=2.7, p=0.01. In conclusion, the novelty of our study is that cotrimoxazole might increase the risk of SSTI in regions where cotrimoxazole resistance is high and associated with PVL. This finding needs to be confirmed in prospective studies.
Full Text Available BACKGROUND: Extensive spread of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA in the United States, and the concomitant increase in severe invasive staphylococcal infections, including osteomyelitis, in healthy children, has led to renewed interest in Panton-Valentine leukocidin (PVL. However, the pathogenetic role of PVL in staphylococcal infections remains controversial, possibly because it depends on the site of infection. METHODOLOGY/PRINCIPAL FINDINGS: We compared the course of experimental rabbit osteomyelitis due to the PVL-positive CA-MRSA strain USA 300 (LAC and its PVL-negative isogenic derivative (LACDeltapvl, using a low and a high inoculum (8x10(5 and 4x10(8 CFU. With the low inoculum, bone infection was less frequent on day 7 (D7 and day 28 (D28 with LACDeltapvl than with LAC (respectively 12/19 and 18/19 animals, p = 0.042. With the high inoculum of both strains, all the animals were infected on D7 and the infection persisted on D28 in almost every case. However, tibial bacterial counts and the serum CRP concentration fell significantly between D7 and D28 with LACDeltapvl but not with LAC. Respectively 67% and 60% of LAC-infected rabbits had bone deformation and muscle/joint involvement on D7, compared to 0% and 7% of LACDeltapvl-infected rabbits (p = 0.001 and p = 0.005 respectively. Between D0 and D28, the anti-PVL antibody titer increased significantly only with the high inoculum of LAC. CONCLUSIONS/SIGNIFICANCE: PVL appears to play a role in the persistence and rapid local extension of rabbit osteomyelitis, in keeping with the greater severity of human bone infections due to PVL-positive S. aureus. The possible therapeutic implications of these findings are discussed.
Hefzy, Enas Mamdouh; Hassan, Gamal Mohamedin; Abd El Reheem, Fadwa
Transmission of methicillin-resistant Staphylococcus aureus (MRSA) among patients is linked mainly to health care personnel. The Panton-Valentine leukocidin (PVL) is a cytotoxin that causes leukocyte lysis. Virulence of pvl-positive-MRSA has been attributed to its ability to express PVL toxin. Swabs for detection of nasal carriage of pvl-positive MRSA among health care personnel at Fayoum University Hospital, Fayoum, Egypt, were collected from 223 health care personnel including 70 doctors (31.4%), 95 nurses (42.6%), 21 laboratory technicians (9.4%), and 37 housekeeping staff (16.6%). Detection of MRSA was done using conventional screening methods and confirmed by multiplex polymerase chain reaction (PCR) for mecA, or its homologue mecC, and pvl genes amplification. Re-swabbing after decolonization therapy was done to evaluate the efficacy of decolonization therapy. Fifty-one of 223 participants (22.9%) were colonized with S. aureus. This included 13.5% (30/223) colonized with MRSA and 2.2% (5/223) colonized with PVL-positive MRSA. Moreover, all MRSA isolates were negative for mecC genes. Decolonization therapy was successful in 80% of MRSA carriers including all pvl-positive MRSA carriers. This is the first report on nasal carriage of pvl-positive MRSA among Egyptian health care personnel. High carriage rate of MRSA among health care personnel has been attributed mainly to poor hand hygiene compliance and non-judicious use of antibiotics. Improving compliance, reducing antibiotic overuse, screening for carriers, and decolonization are recommended strategies for reducing the spread of MRSA. Multiplex PCR could be used for confirmation of results obtained by conventional phenotypic methods.
Boakes, E.; Kearns, A. M.; Ganner, M.; Perry, C.; Hill, R. L.; Ellington, M. J.
Genetically diverse community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) can harbor a bacteriophage encoding Panton-Valentine leukocidin (PVL) lysogenized into its chromosome (prophage). Six PVL phages (ΦPVL, Φ108PVL, ΦSLT, ΦSa2MW, ΦSa2USA, and ΦSa2958) are known, and single-nucleotide polymorphisms (SNPs) in the PVL genes have been reported. We sought to determine the distribution of lysogenized PVL phages among MRSA strains with PVL (PVL-MRSA strains), the PVL gene sequences, and the chromosomal phage insertion sites in 114 isolates comprising nine clones of PVL-MRSA that were selected for maximal underlying genetic diversity. The six PVL phages were identified by PCR; ΦSa2USA was present in the highest number of different lineages (multilocus sequence type clonal complex 1 [CC1], CC5, CC8, and sequence type 93 [ST93]) (n = 37 isolates). Analysis of 92 isolates confirmed that PVL phages inserted into the same chromosomal insertion locus in CC22, -30, and -80 but in a different locus in isolates of CC1, -5, -8, -59, and -88 and ST93 (and CC22 in two isolates). Within the two different loci, specific attachment motifs were found in all cases, although some limited inter- and intralineage sequence variation occurred. Overall, lineage-specific relationships between the PVL phage, the genes that encode the toxin, and the position at which the phage inserts into the host chromosome were identified. These analyses provide important insights into the microepidemiology of PVL-MRSA, will prove a valuable adjunct in outbreak investigation, and may help predict the emergence of new strains. PMID:21106787
Association of Panton Valentine Leukocidin (PVL) genes with methicillin resistant Staphylococcus aureus (MRSA) in Western Nepal: a matter of concern for community infections (a hospital based prospective study)
Bhatta, Dharm R.; Cavaco, Lina; Nath, Gopal
Methicillin resistant Staphylococcus aureus (MRSA) is a major human pathogen associated with nosocomial and community infections. Panton Valentine leukocidin (PVL) is considered one of the important virulence factors of S. aureus responsible for destruction of white blood cells, necrosis...... and apoptosis and as a marker of community acquired MRSA. This study was aimed to determine the prevalence of PVL genes among MRSA isolates and to check the reliability of PVL as marker of community acquired MRSA isolates from Western Nepal. A total of 400 strains of S. aureus were collected from clinical...... specimens and various units (Operation Theater, Intensive Care Units) of the hospital and 139 of these had been confirmed as MRSA by previous study. Multiplex PCR was used to detect mecA and PVL genes. Clinical data as well as antimicrobial susceptibility data was analyzed and compared among PVL positive...
Correa-Jiménez, Oscar; Pinzón-Redondo, Hernando; Reyes, Niradiz
Panton-Valentine leucocidin (PVL) is a pore-forming toxin that has been epidemiologically associated with CA-MRSA infections. However, its role in the pathogenicity of Staphylococcus aureus is still unclear. We evaluated the prevalence of PVL-coding genes in methicillin-resistant (MRSA) and methicillin-sensitive (MSSA) isolates that cause infections in pediatric patients in the city of Cartagena, Colombia. We obtained S. aureus isolates from patients at the Napoleon Franco Pareja Children's Hospital in Cartagena. Then, we evaluated the presence of the nuc, mecA, and PVL genes in these isolates by multiplex PCR and determined the antibiotic susceptibility profiles using CLSI standards. We further correlated methicillin susceptibility and the presence of PVL genes with clinical variables. Overall PVL prevalence in S. aureus isolates was 73.91%, with a frequency of 80.92% among MRSA isolates and 67.59% among MSSA. We found a correlation between erythromycin resistance and lack of PVL and found that PVL+ cases were more common in older patients. We found a high PVL prevalence in both MRSA and MSSA isolates, in concordance with previous regional reports. Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.
Santosaningsih, Dewi; Santoso, Sanarto; Budayanti, Nyoman S; Kuntaman, Kuntaman; Lestari, Endang S; Farida, Helmia; Hapsari, Rebriarina; Hadi, Purnomo; Winarto, Winarto; Milheiriço, Catarina; Maquelin, Kees; Willemse-Erix, Diana; van Belkum, Alex; Severin, Juliëtte A; Verbrugh, Henri A
Data of Staphylococcus aureus carriage in Indonesian hospitals are scarce. Therefore, the epidemiology of S. aureus among surgery patients in three academic hospitals in Indonesia was studied. In total, 366 of 1,502 (24.4%) patients carried S. aureus. The methicillin-resistant S. aureus (MRSA) carriage rate was 4.3%, whereas 1.5% of the patients carried Panton-Valentine leukocidin (PVL)-positive methicillin-sensitive S. aureus (MSSA). Semarang and Malang city (odds ratio [OR] 9.4 and OR 9.0), being male (OR 2.4), hospitalization for more than 5 days (OR 11.708), and antibiotic therapy during hospitalization (OR 2.6) were independent determinants for MRSA carriage, whereas prior hospitalization (OR 2.5) was the only one risk factor for PVL-positive MSSA carriage. Typing of MRSA strains by Raman spectroscopy showed three large clusters assigned type 21, 24, and 38, all corresponding to ST239-MRSA-SCCmec type III. In conclusion, MRSA and PVL-positive MSSA are present among patients in surgical wards in Indonesian academic hospitals.
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.
Mohammad Reza Pourmand
Full Text Available Background: Methicillin-Resistant Staphylococcus aureus (MRSA is a major cause of Nosocomial and community infections that are becoming increasingly difficult to combat, because of emerging resistance to all classes of antibiotics. Moreover Panton-Valentine leukocidin (PVL is an important virulence factor in S. aureus and causes white blood cell destruction, necrosis and accelerated apoptosis. The aim of this study was to determine the frequency of PVL-positive MRSA in cutaneous infections, for epidemiological purposes and also to determine antibiotic resistance of the isolates.Methods: Collectively, 56 isolates of S. aureus were obtained from Isfahan University of Medical sciences affiliated hospitals and confirmed with biochemical tests (coagulase, mannitol fermentation, and DNase. Then polymerase chain reaction (PCR was used to detect pvl gene. Coagulase gene was used as internal control. The antibiotic susceptibility of all isolates to methicillin was determined using disk diffusion method.Results: Out of 56 isolates 14.3% were PVL positive that 37.5% were from abscess and 62.5% were from wound. Among all of these isolates 67.8% were MRSA and also 75% of PVL-positive isolates were MRSA.Conclusion: The prevalence of PVL positive MRSA in cutaneous isolates is high. Future works are necessary for a more complete understanding of distribution of these virulent isolates in nasal carriers to decrease the risk of infections.
Yang, Alice Kar Lai, E-mail: email@example.com [Program of Biochemistry, School of Life Sciences, The Chinese University of Hong Kong (Hong Kong); Lu, Haifei, E-mail: firstname.lastname@example.org [Center for Advanced Research in Photonics, Department of Electronic Engineering, The Chinese University of Hong Kong (Hong Kong); Wu, Shu Yuen, E-mail: email@example.com [Center for Advanced Research in Photonics, Department of Electronic Engineering, The Chinese University of Hong Kong (Hong Kong); Kwok, Ho Chin, E-mail: firstname.lastname@example.org [Center for Advanced Research in Photonics, Department of Electronic Engineering, The Chinese University of Hong Kong (Hong Kong); Ho, Ho Pui, E-mail: email@example.com [Center for Advanced Research in Photonics, Department of Electronic Engineering, The Chinese University of Hong Kong (Hong Kong); Yu, Samuel, E-mail: firstname.lastname@example.org [The MacDiarmid Institute for Advanced Materials and Nanotechnology, Christchurch (New Zealand); Izon Science, PO Box 39-168, Harewood, Christchurch 8545 (New Zealand); Cheung, Anthony Ka Lun, E-mail: email@example.com [Program of Biochemistry, School of Life Sciences, The Chinese University of Hong Kong (Hong Kong); Kong, Siu Kai, E-mail: firstname.lastname@example.org [Program of Biochemistry, School of Life Sciences, The Chinese University of Hong Kong (Hong Kong)
Graphical abstract: -- Highlights: •A novel diagnostic assay is developed to detect the MRSA's Panton-Valentine Leukocidin toxin. •Detection is based on target DNA amplification at one single temperature at 65 °C by LAMP. •Amplicons are then hybridized with 2 Au-nanoparticles with specific DNA probes for sensing. •The supra-assemblies are subsequently sensed by resistive pulse sensing. •Detection limit: ∼200 copies of DNA; time for detection: completed within 2 h. -- Abstract: This report describes a novel diagnostic assay for rapid detection of the Panton-Valentine Leukocidin (PVL) toxin of methicillin-resistant Staphylococcus aureus (MRSA) utilizing resistive pulse sensing (RPS), loop-mediated isothermal DNA amplification (LAMP) in combination with gold nanoparticles (AuNPs). The PVL DNA from MRSA was specifically amplified by LAMP using four primers at one temperature (65 °C). The DNA products with biotin were then conjugated to a first AuNP1 (55 ± 2 nm) through biotin–avidin binding. A second AuNP2 (30 ± 1.5 nm) coated with a specific DNA probe hybridized with the LAMP DNA products at the loop region to enhance assay sensitivity and specificity, to generate supra-AuNP1-DNA-AuNP2 assemblies. Scanning electron microscopy confirmed the presence of these supra-assemblies. Using RPS, detection and quantitation of the agglomerated AuNPs were performed by a tunable fluidic nanopore sensor. The results demonstrate that the LAMP-based RPS sensor is sensitive and rapid for detecting the PVL DNA. This technique could achieve a limit of detection (LOD) up to about 500 copies of genomic DNA from the bacteria MRSA MW2 and the detection can be completed within two hours with a straightforward signal-to-readout setup. It is anticipated that this LAMP-based AuNP RPS may become an effective tool for MRSA detection and a potential platform in clinical laboratory to report the presence or absence of other types of infectious agents.
Schefold Joerg C
Full Text Available Abstract We report a case of fulminant multiple organ failure including the Acute Respiratory Distress Syndrome (ARDS, haemodynamic, and renal failure due to community-acquired methicillin-sensitive Panton Valentine Leukocidin (PVL positive spa-type 284 (ST121 Staphylococcus aureus septic shock. The patient's first clinical symptom was necrotizing pneumonia. Despite organism-sensitive triple antibiotic therapy with linezolid, imipenem and clindamycin from the first day of treatment, progressive abscess formation in multiple skeletal muscles was observed. As a result, repeated surgical interventions became necessary. Due to progressive soft tissue infection, the anti-microbial therapy was changed to a combination of clindamycin and daptomycin. Continued surgical and antimicrobial therapy finally led to a stabilisation of the patients' condition. The clinical course of our patient underlines the existence of a "PVL-syndrome" which is independent of in vitro Staphylococcus aureus susceptibility. The PVL-syndrome should not only be considered in patients with soft tissue or bone infection, but also in patients with pneumonia. Such a condition, which may easily be mistaken for uncomplicated pneumonia, should be treated early, aggressively and over a long period of time in order to avoid relapsing infection.
Hayez, Davy; Da Silva, Sonia; Labrousse, Delphine; Biek, Donald; Badiou, Cedric; Dumitrescu, Oana; Guerard, Pascal; Charles, Pierre-Emmanuel; Piroth, Lionel; Lina, Gerard; Vandenesch, Francois; Chavanet, Pascal
Ceftaroline, the active metabolite of the prodrug ceftaroline fosamil, is a cephalosporin with broad-spectrum in vitro activity against Gram-positive organisms, including methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Streptococcus pneumoniae (MDRSP), and common Gram-negative pathogens. This study investigated the in vivo activity of ceftaroline fosamil compared with clindamycin, linezolid, and vancomycin in a severe pneumonia model due to MRSA-producing Panton-Valentine leukocidin (PVL). A USA300 PVL-positive clone was used to induce pneumonia in rabbits. Infected rabbits were randomly assigned to no treatment or simulated human-equivalent dosing with ceftaroline fosamil, clindamycin, linezolid, or vancomycin. Residual bacterial concentrations in the lungs and spleen were assessed after 48 h of treatment. PVL expression was measured using a specific enzyme-linked immunosorbent assay (ELISA). Ceftaroline, clindamycin, and linezolid considerably reduced mortality rates compared with the control, whereas vancomycin did not. Pulmonary and splenic bacterial titers and PVL concentrations were greatly reduced by ceftaroline, clindamycin, and linezolid. Ceftaroline, clindamycin, and linezolid were associated with reduced pulmonary tissue damage based on significantly lower macroscopic scores. Ceftaroline fosamil, clindamycin, and, to a lesser extent, linezolid were efficient in reducing bacterial titers in both the lungs and spleen and decreasing macroscopic scores and PVL production compared with the control. PMID:24395236
Crémieux, Anne-Claude; Saleh-Mghir, Azzam; Danel, Claire; Couzon, Florence; Dumitrescu, Oana; Lilin, Thomas; Perronne, Christian; Etienne, Jérôme; Lina, Gerard; Vandenesch, François
Severe sepsis, combining acute osteomyelitis and lung involvement, has been described increasingly in healthy children with the spread of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). Outcomes (mortality, hematogenous spread, lung and bone involvements) of rabbit osteomyelitis caused by CA-MRSA LAC(WT) USA300 and its Panton-Valentine leukocidin (PVL)- and α-hemolysin (Hla)-negative isogenic derivatives (LACΔpvl and LACΔhla, respectively) were compared. Three days after inoculation (D3), all LAC(WT)- and LACΔpvl-, and 72% of LACΔhla-infected rabbits had no hematogenous spread and similar lung and bone bacterial densities. LACΔpvl and LACΔhla caused less severe histological lung lesions than LAC(WT) (P ≤ .01). Between D3 and D9, 10 (53%) LAC(WT)-, 11 (55%) LACΔpvl-, but no LACΔhla-infected rabbits (P < .005) died of severe sepsis with disseminated infection. Unlike deceased animals, most LAC(WT), LACΔpvl, and LACΔhla D14 survivors had no hematogenous spread (P < .001). LAC(WT) (88%) caused more bone abscesses than LACΔpvl (0, P = .001) or LACΔhla (30%, P = .01). In this model, both PVL and Hla seemed to be required for early lung involvement via hematogenous spread. Hla, but not PVL, significantly impacted severe sepsis-related mortality. PVL was the predominant factor determining late-stage bone abscesses.
Full Text Available Background Staphylococcus aureus is one of the most important organisms involved in nosocomial infection acquired by patients. In recent years, the appearance of methicillin-resistant S. aureus (MRSA has turned the treatment of these infections into a serious challenge. Surface proteins, such as fibronectin binding proteins (FnBP, and the ability to produce Panton-Valentine leukocidin (PVL are important factors in pathogenesis of this organism. Objectives The purpose of this study was to determine the prevalence of disease-associated genes in the clinical isolates of S. aureus encoding FNB and PVL, collected from the educational hospitals of Qazvin, Iran. Patients and Methods This was a descriptive, cross-sectional study in which a total of 103 isolates of methicillin-resistant S. aureus were collected from hospitalized patients in teaching hospitals of Qazvin, during 2013 - 2014. Initially, the identification of isolates was performed according to the standard laboratory methods, followed by confirming the presence of the femA gene, a gene specific to S. aureus. Later, the prevalence of virulence genes (fnb and pvl was investigated by the PCR method, using specific primers. PCR products were sequenced to confirm the presence of the target genes. Results The results of this study showed that among 103 isolates of S. aureus resistant to methicillin, 88 isolates were positive for the presence of the pvl and fnb genes, with the fnb gene present in 86 (83.5% isolates and the pvl gene only in 2 (1.9% isolates. Conclusions The results of the present study indicate the presence of the pvl and fnb genes in the strains of S. aureus isolated from clinical specimens collected from the patients admitted to teaching hospitals in Qazvin. Considering the clinical significance of these organisms, and their potential in threatening public health systems, the identification, treatment, and infection control management of patients infected with these organisms is
Poojary, Niveditha Sundar; Ramlal, Shylaja; Urs, Radhika Madan; Sripathy, Murali Harishchandra; Batra, Harsh Vardhan
Panton-Valentine Leukocidin (PVL) produced by community acquired methicillin Staphylococcus aureus (CA-MRSA) involved in skin and soft-tissue infections and necrotizing pneumonia comprised of two fractions, namely PVL S and PVL F. In the present study, three monoclonal antibodies designated as MAb1, MAb9 and MAb10 were generated against recombinant PVL-S (35kDa) protein of S. aureus. All the three MAbs specifically reacted to confirm PVL-S positive strains of S. aureus recovered from clinical samples in Western blot analysis. Similarly all the three MAbs did not show any binding to other tested 14 different pathogenic bacteria belonging to other genera and species in Western blot analysis. Furthermore, a simple dot-ELISA method was standardized for the identification of PVL-S toxin containing S. aureus strains. Initially in dot-ELISA, Protein A (Spa) of S. aureus posed background noise problems due to the non-specific binding of antibodies resulting in false positive reactions. With the addition of 10mM diethylpyrocarbonate (DEPC) along with 5% milk in PBS in the blocking step prevented this non-specific binding of Spa to mouse anti-PVL monoclonal antibodies in dot-ELISA. Once standardized, this simple dot-ELISA was evaluated with nine PVL positive strains recovered from food, environmental and clinical samples and the results were compared with PCR assay for the presence of PVL toxin genes and also with Western blot analysis. A 100% correlation was found between dot-ELISA, PCR assay and Western blot analysis. Collectively our results suggest the newly developed simple dot-ELISA system can be of immense help in providing, rapid detection of the PVL toxin containing S. aureus strains at a relatively low cost and will be a valuable tool for the reliable identification of CA-MRSA. Copyright © 2014 Elsevier GmbH. All rights reserved.
Full Text Available The impact of Panton-Valentine leukocidin (PVL on the severity of complicated skin and skin structure infections (cSSSI caused by Staphylococcus aureus is controversial. We evaluated potential associations between clinical outcome and PVL presence in both methicillin-resistant S. aureus (MRSA and methicillin-susceptible S. aureus (MSSA isolates from patients enrolled in two large, multinational phase three clinical trials assessing ceftaroline fosamil for the treatment of cSSSI (the CANVAS 1 and 2 programs. Isolates from all microbiologically evaluable patients with monomicrobial MRSA or MSSA infections (n = 473 were genotyped by PCR for pvl and underwent pulsed-field gel electrophoresis (PFGE. Genes encoding pvl were present in 266/473 (56.2% isolates. Infections caused by pvl-positive S. aureus were associated with younger patient age, North American acquisition, and presence of major abscesses (P<0.001 for each. Cure rates of patients infected with pvl-positive and pvl-negative S. aureus were similar overall (93.6% versus 92.8%; P = 0.72, and within MRSA-infected (94.5% vs. 93.1%; P = 0.67 and MSSA-infected patients (92.2% vs. 92.7%; P = 1.00. This finding persisted after adjustment for multiple patient characteristics. Outcomes were also similar when USA300 PVL+ and non-USA300 PVL+ infections were compared. The results of this contemporary, international study suggest that pvl presence was not the primary determinant of outcome in patients with cSSSI due to either MRSA or MSSA.
Sanchini, A; Del Grosso, M; Villa, L; Ammendolia, M G; Superti, F; Monaco, M; Pantosti, A
Panton-Valentine leukocidin (PVL) is the hallmark of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) but can also be found in methicillin-susceptible S. aureus (MSSA) sharing pathogenic and epidemiological characteristics of CA-MRSA. PVL is encoded by two co-transcribed genes that are carried by different staphylococcal bacteriophages. We applied an extended PCR-based typing scheme for the identification of two morphological groups (elongated-head group and icosahedral-head group I phages) and specific PVL phage types in S. aureus isolates recovered in Italy. We examined 48 PVL-positive isolates (25 MSSA and 23 MRSA) collected from different hospital laboratories from April 2005 to May 2011. spa typing, multilocus sequence typing and staphylococcal cassette chromosome mec typing were applied to categorize the isolates. Phage typeability was 48.0% in MSSA and 91.3% in MRSA, highlighting the limitation of the PCR typing scheme when applied to PVL-positive MSSA. Five different PVL phages and two variants of a known phage were detected, the most prevalent being ΦSa2usa, recovered in 15 out of 48 (31.2%) isolates, and carried by both MSSA and MRSA belonging to CC8 and CC5. The recently described ΦTCH60 was recovered in four isolates. A PVL phage (ΦSa119) from an ST772 MRSA, that was not detected using the previous typing scheme, was sequenced, and new primers were designed for the identification of the icosahedral-head group II PVL phages present in ST772 and ST59 MRSA. A comprehensive PVL-phage typing can contribute to the understanding of the epidemiology and evolution of PVL-positive MSSA and MRSA. © 2014 The Authors Clinical Microbiology and Infection © 2014 European Society of Clinical Microbiology and Infectious Diseases.
Association of Panton Valentine Leukocidin (PVL) genes with methicillin resistant Staphylococcus aureus (MRSA) in Western Nepal: a matter of concern for community infections (a hospital based prospective study).
Bhatta, Dharm R; Cavaco, Lina M; Nath, Gopal; Kumar, Kush; Gaur, Abhishek; Gokhale, Shishir; Bhatta, Dwij R
Methicillin resistant Staphylococcus aureus (MRSA) is a major human pathogen associated with nosocomial and community infections. Panton Valentine leukocidin (PVL) is considered one of the important virulence factors of S. aureus responsible for destruction of white blood cells, necrosis and apoptosis and as a marker of community acquired MRSA. This study was aimed to determine the prevalence of PVL genes among MRSA isolates and to check the reliability of PVL as marker of community acquired MRSA isolates from Western Nepal. A total of 400 strains of S. aureus were collected from clinical specimens and various units (Operation Theater, Intensive Care Units) of the hospital and 139 of these had been confirmed as MRSA by previous study. Multiplex PCR was used to detect mecA and PVL genes. Clinical data as well as antimicrobial susceptibility data was analyzed and compared among PVL positive and negative MRSA isolates. Out of 139 MRSA isolates, 79 (56.8 %) were PVL positive. The majority of the community acquired MRSA (90.4 %) were PVL positive (Positive predictive value: 94.9 % and negative predictive value: 86.6 %), while PVL was detected only in 4 (7.1 %) hospital associated MRSA strains. None of the MRSA isolates from hospital environment was found positive for the PVL genes. The majority of the PVL positive strains (75.5 %) were isolated from pus samples. Antibiotic resistance among PVL negative MRSA isolates was found higher as compared to PVL positive MRSA. Our study showed high prevalence of PVL among community acquired MRSA isolates. Absence of PVL among MRSA isolates from hospital environment indicates its poor association with hospital acquired MRSA and therefore, PVL may be used a marker for community acquired MRSA. This is first study from Nepal, to test PVL among MRSA isolates from hospital environment.
Velasco, Valeria; Sherwood, Julie S.; Rojas-García, Pedro P.; Logue, Catherine M.
The aim of this study was to compare a real-time PCR assay, with a conventional culture/PCR method, to detect S. aureus, mecA and Panton-Valentine Leukocidin (PVL) genes in animals and retail meat, using a two-step selective enrichment protocol. A total of 234 samples were examined (77 animal nasal swabs, 112 retail raw meat, and 45 deli meat). The multiplex real-time PCR targeted the genes: nuc (identification of S. aureus), mecA (associated with methicillin resistance) and PVL (virulence factor), and the primary and secondary enrichment samples were assessed. The conventional culture/PCR method included the two-step selective enrichment, selective plating, biochemical testing, and multiplex PCR for confirmation. The conventional culture/PCR method recovered 95/234 positive S. aureus samples. Application of real-time PCR on samples following primary and secondary enrichment detected S. aureus in 111/234 and 120/234 samples respectively. For detection of S. aureus, the kappa statistic was 0.68–0.88 (from substantial to almost perfect agreement) and 0.29–0.77 (from fair to substantial agreement) for primary and secondary enrichments, using real-time PCR. For detection of mecA gene, the kappa statistic was 0–0.49 (from no agreement beyond that expected by chance to moderate agreement) for primary and secondary enrichment samples. Two pork samples were mecA gene positive by all methods. The real-time PCR assay detected the mecA gene in samples that were negative for S. aureus, but positive for Staphylococcus spp. The PVL gene was not detected in any sample by the conventional culture/PCR method or the real-time PCR assay. Among S. aureus isolated by conventional culture/PCR method, the sequence type ST398, and multi-drug resistant strains were found in animals and raw meat samples. The real-time PCR assay may be recommended as a rapid method for detection of S. aureus and the mecA gene, with further confirmation of methicillin-resistant S. aureus (MRSA) using
Ünal, Nilgün; Askar, Şinasi; Macun, Hasan Ceyhun; Sakarya, Fatma; Altun, Belgin; Yıldırım, Murat
The aims of this study were to determine the existence of pvl gene, some toxin genes, and mecA gene in Staphylococcus aureus strains isolated from sheep milk and to examine antimicrobial resistance profiles in staphylococci from sheep and goats' milk. The milk samples were collected from 13 different small ruminant farms in Kirikkale province from February to August 2009. A total of 1,604 half-udder milk samples from 857 ewes and 66 half-udder milk samples from 33 goats were collected. Staphylococcus spp. were isolated and identified from the samples. Toxin genes and mecA gene among S. aureus strains were determined by PCR. Antimicrobial susceptibility of staphylococci was examined by the disk diffusion method on Mueller-Hinton agar, and interpreted according to the Clinical Laboratory Standards Institute (CLSI) guidelines. The prevalence of subclinical intramammary infection in both ewes and goats was 5.2%. The most prevalent subclinical mastitis agents were coagulase-negative staphylococci and S. aureus with prevalences 2.8% (n:46) and 1.3% (n = 21), respectively. The prevalence of resistances in isolated Staphylococcus spp. to penicilin G, tetracycline, erythromycin, gentamicin, and enrofloxacin were found as 26.9% (18), 7.5% (5), 6.0% (4), 3.0% (2), and 1.5% (1), respectively. Only 3 of the 21 S. aureus ewe isolates (13.4%) were shown to harbor enterotoxin genes being either seh, sej or sec. However, fourteen (66.6%) of the 21 S. aureus isolates had pvl gene while none of the isolates harbored mecA gene. In conclusion, Staphylococci were shown to be the most prevalent bacteria isolated from subclinical mastitis of ewes and goats and these isolates were susceptible to most of the antibiotics. In addition, S. aureus strains isolated from ewes were harboring few staphylococcal enterotoxin genes. However, Panton-Valentine leukocidin produced by S. aureus could be an important virulence factor and contribute to subclinical mastitis pathogenicity.
Landrum, Michael L; Lalani, Tahaniyat; Niknian, Minoo; Maguire, Jason D; Hospenthal, Duane R; Fattom, Ali; Taylor, Kimberly; Fraser, Jamie; Wilkins, Kenneth; Ellis, Michael W; Kessler, Paul D; Fahim, Rafaat E F; Tribble, David R
We conducted a randomized, double-blind, placebo-controlled dose-escalation study in healthy adults to evaluate the safety and immunogenicity of recombinant Staphylococcus aureus candidate vaccine antigens, recombinant α-toxoid (rAT) and a sub-unit of Panton-Valentine leukocidin (rLukS-PV). 176 subjects were enrolled and randomized within 1 of 11 treatment cohorts: monovalent rAT or rLukS-PV dosages of 10, 25, 50, and 100 μg; bivalent rAT:rLukS dosages of 10:10, 25:25, and 50:50 μg; and alum or saline placebo. All subjects were assessed at Days 0, 7, 14, 28, and 84. Subjects in the 50:50 μg bivalent cohort received a second injection on Day 84 and were assessed on Days 98 and 112. Incidence and severity of reactogenicity and adverse events (AEs) were compared. Geometric mean serum concentrations (GMC) and neutralizing activity of anti-rAT and anti-rLukS-PV IgG were assessed. Reactogenicity incidence was significantly higher in vaccine than placebo recipients (77% versus 55%, respectively; p = 0.006). However, 77% of reactogenicity events were mild and 19% were moderate in severity. The AE incidence and severity were similar between the cohorts. All monovalent and bivalent rAT dosages resulted in a significant increase in the anti-rAT IgG and anti- rLukS-PV GMCs between day 0 and 28 compared with placebo, and persisted through Day 84. Exploratory subgroup analyses suggested a higher GMC and neutralizing antibody titers for the 50 μg monovalent or bivalent rAT and rLukS-PV dose as compared to the other doses. No booster effect was observed after administration of the second dose. We conclude that the rAT and rLukS-PV vaccine formulations were well-tolerated and had a favorable immunogenicity profile, producing antibody with neutralizing activity through day 84. There was no benefit observed with a booster dose of the vaccine.
Prevalence and Genetic Characteristics of Staphylococcus aureus and Staphylococcus argenteus Isolates Harboring Panton-Valentine Leukocidin, Enterotoxins, and TSST-1 Genes from Food Handlers in Myanmar.
Aung, Meiji Soe; San, Thida; Aye, Mya Mya; Mya, San; Maw, Win Win; Zan, Khin Nyein; Htut, Wut Hmone Win; Kawaguchiya, Mitsuyo; Urushibara, Noriko; Kobayashi, Nobumichi
Asymptomatic carriers of toxigenic Staphylococcus aureus are potential source of diseases, including food poisoning. Toxigenic potential and genetic traits of colonizing S. aureus were investigated for 563 healthy food handlers in Myanmar. Carriage of S. aureus was found in 110 individuals (19.5%), and a total of 144 S. aureus isolates were recovered from nasal cavities (110 isolates) and hands (34 isolates). Panton-Valentine leucocidin genes (pvl) were detected in 18 isolates (12.5%), among which 11 isolates were classified into coa-VIa, agr type III, and ST1930 (CC96) that had been also detected in pvl-positive clinical isolates in Myanmar. A pvl-positive, ST2250 nasal isolate was identified as S. argenteus, a novel coagulase-positive staphylococcus species. Toxic shock syndrome toxin-1 (TSST-1) gene was detected in five pvl-negative isolates. All of the 144 isolates harbored at least one of the 21 enterotoxin(-like) gene(s). The most prevalent enterotoxin(-like) gene was selw (98%), followed by selx (97%), sei (28%), sely (28%), sem (26%), sel (24%), and sea and sec (22% each). Considerable genetic diversity with five groups was detected for selw. The present study revealed the relatively high rate of pvl, as well as the wide distribution of enterotoxin(-like) genes among colonizing S. aureus in Myanmar.
Full Text Available The objectives of the present study were to investigate the rate of S. aureus nasal carriage and molecular characteristics in hospital and community settings in Bobo Dioulasso, Burkina Faso. Nasal samples (n=219 were collected from 116 healthy volunteers and 103 hospitalized patients in July and August 2014. Samples were first screened using CHROMagar Staph aureus chromogenic agar plates, and S. aureus strains were identified by mass spectrometry. Antibiotic susceptibility was tested using the disk diffusion method on Müller-Hinton agar. All S. aureus isolates were genotyped using DNA microarray. Overall, the rate of S. aureus nasal carriage was 32.9% (72/219, 29% in healthy volunteers and 37% in hospital patients. Among the S. aureus isolates, only four methicillin-resistant S. aureus (MRSA strains were identified and all in hospital patients (3.9%. The 72 S. aureus isolates from nasal samples belonged to 16 different clonal complexes, particularly to CC 152-MSSA (22 clones and CC1-MSSA (nine clones. Two clones were significantly associated with community settings: CC1-MSSA and CC45-MSSA. The MRSA strains belonged to the ST88-MRSA-IV or the CC8-MRSA-V complex. A very high prevalence of toxinogenic strains 52,2% (36/69, containing Panton-Valentine leucocidin- and EDIN-encoding genes, was identified among the S. aureus isolates in community and hospital settings. This study provides the first characterization of S. aureus clones and their genetic characteristics in Burkina Faso. Altogether, it highlights the low prevalence of antimicrobial resistance, high diversity of methicillin-sensitive S. aureus clones and high frequency of toxinogenic S. aureus strains.
Rabøl, Peter Hedelund; Dessau, Ram Benny; Warnecke, Mads
We describe a case of fatal pneumonia in a previously healthy 14-year-old boy. The patient was severely affected at the time of admission with high fever, tachypnea, tachycardia and peripheral cyanosis. The condition worsened despite treatment with antibiotics as well as respiratory and pressure ...... support. Acidosis and critical leucopenia supervened and the patient died just short of 24 hours after admission. Subsequent bacterial cultivation showed Panton-Valentine Leucocidin-producing Staphylococcus aureus....
Spaan, András N.|info:eu-repo/dai/nl/357396995; Schiepers, Ariën; De Haas, Carla J C; Van Hooijdonk, Davy D J J; Badiou, Cédric; Contamin, Hugues; Vandenesch, François; Lina, Gérard; Gerard, Norma P.; Gerard, Craig; Van Kessel, Kok P M; Henry, Thomas; Van Strijp, Jos A G|info:eu-repo/dai/nl/074307053
Staphylococcus aureus is well adapted to the human host. Evasion of the host phagocyte response is critical for successful infection. The staphylococcal bicomponent pore-forming toxins Panton-Valentine leukocidin LukSF-PV (PVL) and γ-hemolysin CB (HlgCB) target human phagocytes through interaction
Dunlop, Rebecca L E
Neonatal necrotising fasciitis is very rare in comparison to the adult presentation of the disease and a Plastic Surgeon may only encounter one such case during his or her career. Often this is initially misdiagnosed and managed as simple cellulitis. It generally affects previously healthy babies, the site is often the lower back area and a history of minor skin trauma may be elicited. The causative organism is usually Streptococcus or polymicrobial, as is the case in the adult population. We present the case of a previously healthy 11-day-old infant with idiopathic, rapidly progressive necrotising fasciitis of the back, cause by Methicillin sensitive Staphylococcus aureus (MSSA) infection. The strain was isolated and found to encode the Panton-Valentine Leukocidin genes, which have been associated with particularly severe necrotising infections in other sites, with high mortality. These strains are the subject of specific treatment and eradication guidance in the UK but awareness of this and the importance of obtaining detailed culture typing is likely to be low amongst Plastic Surgeons.
Shore, Anna C
The staphylococcal cfr gene mediates resistance to phenicols, lincosamides, oxazolidinones, pleuromutilins, and streptogramin A, a phenotype that has been termed PhLOPS(A). The cfr gene has mainly been associated with coagulase-negative staphylococcal isolates from animals, and only a few cfr-positive methicillin-resistant Staphylococcus aureus (MRSA) isolates have been described so far. This study reports the first description of a cfr-positive MRSA isolate (M05\\/0060) belonging to the pandemic Panton-Valentine leukocidin (PVL)-positive sequence type 8 MRSA IVa\\/USA300 (ST8-MRSA-IVa\\/USA300) clone. The cfr gene was detected in M05\\/0060 using a DNA microarray which was used to screen PVL-positive MRSA isolates for the presence of virulence genes, typing markers, and antimicrobial resistance genes. Antimicrobial susceptibility testing revealed that M05\\/0060 exhibited the cfr-associated resistance phenotype. Molecular analysis identified the presence of cfr and a second phenicol resistance gene, fexA, on a novel 45-kb conjugative plasmid, which was designated pSCFS7. Within pSCFS7, a DNA segment consisting of cfr, a truncated copy of insertion sequence IS21-558, and a region with homology to the DNA invertase gene bin3 of transposon Tn552 from Bacillus mycoides was integrated into the transposase gene tnpB of the fexA-carrying transposon Tn558. The emergence of a multidrug-resistant cfr-positive variant of ST8-MRSA-IVa\\/USA300 is alarming and requires ongoing surveillance. Moreover, the identification of a novel conjugative plasmid carrying the cfr gene indicates the ability of cfr to spread to other MRSA strains.
Kraef, Christian; Alabi, Abraham S.; Peters, Georg; Becker, Karsten; Kremsner, Peter G.; Rossatanga, Elie G.; Mellmann, Alexander; Grobusch, Martin P.; Zanger, Philipp; Schaumburg, Frieder
Patients infected with the human immuno deficiency virus (HIV) are frequently exposed to antimicrobial agents. This might have an impact on the resistance profile, genetic background and virulence factors of colonizing Staphylococcus aureus. Sub-Saharan Africa is considered to be endemic for
Full Text Available Mast cells are located at host interfaces, such as the skin, and contribute to the first-line defense against pathogens by releasing soluble mediators, including those that induce itching and scratching behavior. Here, we show that delta-hemolysin (Hld and phenol soluble modulins (PSMs PSMα1 and PSMα3, but not alpha-hemolysin (Hla or Panton-Valentine leukocidin (PVL, induce dose-dependent tryptase and lactate dehydrogenase (LDH release by the HMC-1 human mast cell line. Using supernatants from isogenic strains, we verified that tryptase and LDH release was Hld- and PSMα-dependent. PSMα1 and Hld production was detected in 65% and 17% of human Staphylococcus aureus-infected skin abscess specimens, respectively, but they were produced in vitro by all clinical isolates. The results suggest that Hld and PSM-α1 produced in vivo during S. aureus skin infections induce the release of mast cell mediators responsible for itching and scratching behavior, which may enhance skin to skin transmission of S. aureus via the hands. As Hld and PSMs are upregulated by accessory gene regulator (agr, their association may contribute to the elective transmission of S. aureus strains with a functional agr system.
Hodille, Elisabeth; Cuerq, Charlotte; Badiou, Cédric; Bienvenu, Françoise; Steghens, Jean-Paul; Cartier, Régine; Bes, Michèle; Tristan, Anne; Plesa, Adriana; Le, Vien T M; Diep, Binh A; Lina, Gérard; Dumitrescu, Oana
Mast cells are located at host interfaces, such as the skin, and contribute to the first-line defense against pathogens by releasing soluble mediators, including those that induce itching and scratching behavior. Here, we show that delta-hemolysin (Hld) and phenol soluble modulins (PSMs) PSMα1 and PSMα3, but not alpha-hemolysin (Hla) or Panton-Valentine leukocidin (PVL), induce dose-dependent tryptase, and lactate dehydrogenase (LDH) release by the HMC-1 human mast cell line. Using supernatants from isogenic strains, we verified that tryptase and LDH release was Hld- and PSMα-dependent. PSMα1 and Hld production was detected in 65 and 17% of human Staphylococcus aureus -infected skin abscess specimens, respectively, but they were produced in vitro by all clinical isolates. The results suggest that Hld and PSM-α1 produced in vivo during S. aureus skin infections induce the release of mast cell mediators responsible for itching and scratching behavior, which may enhance skin to skin transmission of S. aureus via the hands. As Hld and PSMs are upregulated by accessory gene regulator (agr), their association may contribute to the elective transmission of S. aureus strains with a functional agr system.
Full Text Available Background. Panton-Valentine leukocidin (PVL-producing Staphylococcus aureus is emerging as a serious problem worldwide. There has been an increase in the incidence of necrotizing lung infections in otherwise healthy young people with a very high mortality associated with these strains. Sporadic severe infectious complications after incision of Bartholin's abcesses have been described but involvement of S. aureus is rare. Case report. We present a 23-year-old apparently healthy female patient without any typical predisposing findings who developed severe sepsis with necrotizing pneumonia and multiple abscesses following incision of a Bartholin's abscess. Methicillin-sensitive S. aureus harbouring Panton-Valentine leucocidin genes were cultured from the abscess fluid, multiple blood cultures and a postoperative wound swab. Aggressive antibiotic therapy with flucloxacillin, rifampicin and clindamycin, drainage and intensive supportive care lead finally to recovery. Conclusions. S. aureus, in particular PVL-positive strains, should be considered when a young, immunocompetent person develops a fulminant necrotizing pneumonia. Minor infections—such as Bartholin's abscess—can precede this life-threating syndrome. Bactericidal antistaphylococcal antibiotics are recommended for treatment, and surgical procedures may become necessary.
Emergence of Hospital- and Community-Associated Panton-Valentine Leukocidin-Positive Methicillin-Resistant Staphylococcus aureus Genotype ST772-MRSA-V in Ireland and Detailed Investigation of an ST772-MRSA-V Cluster in a Neonatal Intensive Care Unit
Shore, Anna C.; Corcoran, Suzanne; Tecklenborg, Sarah; Coleman, David C.; O'Connell, Brian
Sequence type 22 (ST22) methicillin-resistant Staphylococcus aureus (MRSA) harboring staphylococcal cassette chromosome mec (SCCmec) IV (ST22-MRSA-IV) has predominated in Irish hospitals since the late 1990s. Six distinct clones of community-associated MRSA (CA-MRSA) have also been identified in Ireland. A new strain of CA-MRSA, ST772-MRSA-V, has recently emerged and become widespread in India and has spread into hospitals. In the present study, highly similar MRSA isolates were recovered from seven colonized neonates in a neonatal intensive care unit (NICU) in a maternity hospital in Ireland during 2010 and 2011, two colonized NICU staff, one of their colonized children, and a NICU environmental site. The isolates exhibited multiantibiotic resistance, spa type t657, and were assigned to ST772-MRSA-V by DNA microarray profiling. All isolates encoded resistance to macrolides [msr(A) and mpb(BM)] and aminoglycosides (aacA-aphD and aphA3) and harbored the Panton-Valentine leukocidin toxin genes (lukF-PV and lukS-PV), enterotoxin genes (sea, sec, sel, and egc), and one of the immune evasion complex genes (scn). One of the NICU staff colonized by ST772-MRSA-V was identified as the probable index case, based on recent travel to India. Seven additional hospital and CA-ST772-MRSA-V isolates recovered from skin and soft tissue infections in Ireland between 2009 and 2011 exhibiting highly similar phenotypic and genotypic characteristics to the NICU isolates were also identified. The clinical details of four of these patients revealed connections with India through ethnic background or travel. Our study indicates that hospital-acquired and CA-ST772-MRSA-V is currently emerging in Ireland and may have been imported from India on several occasions. PMID:22189119
Emergence of hospital- and community-associated panton-valentine leukocidin-positive methicillin-resistant Staphylococcus aureus genotype ST772-MRSA-V in Ireland and detailed investigation of an ST772-MRSA-V cluster in a neonatal intensive care unit.
Brennan, Gráinne I
Sequence type 22 (ST22) methicillin-resistant Staphylococcus aureus (MRSA) harboring staphylococcal cassette chromosome mec (SCCmec) IV (ST22-MRSA-IV) has predominated in Irish hospitals since the late 1990s. Six distinct clones of community-associated MRSA (CA-MRSA) have also been identified in Ireland. A new strain of CA-MRSA, ST772-MRSA-V, has recently emerged and become widespread in India and has spread into hospitals. In the present study, highly similar MRSA isolates were recovered from seven colonized neonates in a neonatal intensive care unit (NICU) in a maternity hospital in Ireland during 2010 and 2011, two colonized NICU staff, one of their colonized children, and a NICU environmental site. The isolates exhibited multiantibiotic resistance, spa type t657, and were assigned to ST772-MRSA-V by DNA microarray profiling. All isolates encoded resistance to macrolides [msr(A) and mpb(BM)] and aminoglycosides (aacA-aphD and aphA3) and harbored the Panton-Valentine leukocidin toxin genes (lukF-PV and lukS-PV), enterotoxin genes (sea, sec, sel, and egc), and one of the immune evasion complex genes (scn). One of the NICU staff colonized by ST772-MRSA-V was identified as the probable index case, based on recent travel to India. Seven additional hospital and CA-ST772-MRSA-V isolates recovered from skin and soft tissue infections in Ireland between 2009 and 2011 exhibiting highly similar phenotypic and genotypic characteristics to the NICU isolates were also identified. The clinical details of four of these patients revealed connections with India through ethnic background or travel. Our study indicates that hospital-acquired and CA-ST772-MRSA-V is currently emerging in Ireland and may have been imported from India on several occasions.
Spaan, András N; Schiepers, Ariën; de Haas, Carla J C; van Hooijdonk, Davy D J J; Badiou, Cédric; Contamin, Hugues; Vandenesch, François; Lina, Gérard; Gerard, Norma P; Gerard, Craig; van Kessel, Kok P M; Henry, Thomas; van Strijp, Jos A G
Staphylococcus aureus is well adapted to the human host. Evasion of the host phagocyte response is critical for successful infection. The staphylococcal bicomponent pore-forming toxins Panton-Valentine leukocidin LukSF-PV (PVL) and γ-hemolysin CB (HlgCB) target human phagocytes through interaction with the complement receptors C5aR1 and C5aR2. Currently, the apparent redundancy of both toxins cannot be adequately addressed in experimental models of infection because mice are resistant to PVL and HlgCB. The molecular basis for species specificity of the two toxins in animal models is not completely understood. We show that PVL and HlgCB feature distinct activity toward neutrophils of different mammalian species, where activity of PVL is found to be restricted to fewer species than that of HlgCB. Overexpression of various mammalian C5a receptors in HEK cells confirms that cytotoxicity toward neutrophils is driven by species-specific interactions of the toxins with C5aR1. By taking advantage of the species-specific engagement of the toxins with their receptors, we demonstrate that PVL and HlgCB differentially interact with human C5aR1 and C5aR2. In addition, binding studies illustrate that different parts of the receptor are involved in the initial binding of the toxin and the subsequent formation of lytic pores. These findings allow a better understanding of the molecular mechanism of pore formation. Finally, we show that the toxicity of PVL, but not of HlgCB, is neutralized by various C5aR1 antagonists. This study offers directions for the development of improved preclinical models for infection, as well as for the design of drugs antagonizing leukocidin toxicity. Copyright © 2015 by The American Association of Immunologists, Inc.
Severity of Nonbullous Staphylococcus aureus Impetigo in Children Is Associated with Strains Harboring Genetic Markers for Exfoliative Toxin B, Panton-Valentine Leukocidin, and the Multidrug Resistance Plasmid pSK41
Koning, Sander; van Belkum, Alex; Snijders, Susan; van Leeuwen, Willem; Verbrugh, Henri; Nouwen, Jan; Op ′t Veld, Mariet; van Suijlekom-Smit, Lisette W. A.; van der Wouden, Johannes C.; Verduin, Cees
Nonbullous impetigo is a common skin infection in children and is frequently caused by Staphylococcus aureus. Staphylococcal toxins and especially exfoliative toxin A are known mediators of bullous impetigo in children. It is not known whether this is also true for nonbullous impetigo. We set out to analyze clonality among clinical isolates of S. aureus from children with nonbullous impetigo living in a restricted geographical area in The Netherlands. We investigated whether staphylococcal nasal carriage and the nature of the staphylococcal strains were associated with the severity and course of impetigo. Bacterial isolates were obtained from the noses and wounds of children suffering from impetigo. Strains were genetically characterized by pulsed-field gel electrophoresis-mediated typing and binary typing, which was also used to assess toxin gene content. In addition, a detailed clinical questionnaire was filled in by each of the participating patients. Staphylococcal nasal carriage seems to predispose the patients to the development of impetigo, and 34% of infections diagnosed in the Rotterdam area are caused by one clonal type of S. aureus. The S. aureus strains harbor the exfoliative toxin B (ETB) gene as a specific virulence factor. In particular, the numbers (P = 0.002) and sizes (P impetigo. The identification of these microbial genetic markers, which are predictive of the severity and the course of the disease, will facilitate guided individualized antimicrobial therapy in the future. PMID:12843036
Severity of nonbullous Staphylococcus aureus impetigo in children is associated with strains harboring genetic markers for exfoliative toxin B, Panton-Valentine leukocidin, and the multidrug resistance plasmid pSK41
S. Koning (Sander); A.F. van Belkum (Alex); S.V. Snijders (Susan); J.L. Nouwen (Jan); M. op 't Veld; J.C. van der Wouden (Hans); C.M. Verduin (Cees); H.A. Verbrugh (Henri); W.B. van Leeuwen (Willem); L.W.A. van Suijlekom-Smit (Lisette)
textabstractNonbullous impetigo is a common skin infection in children and is frequently caused by Staphylococcus aureus. Staphylococcal toxins and especially exfoliative toxin A are known mediators of bullous impetigo in children. It is not known whether this is also true for
Sloan, Tim; Kearns, Angela M.; James, Richard
Limited comprehensive molecular typing data exist currently for Panton-Valentine leucocidin (PVL)-positive, methicillin-sensitive Staphylococcus aureus (PVL-MSSA) clinical isolates. Characterization of PVL-MSSA isolates by multilocus sequence typing (MLST) and spa typing in this study showed a genetic similarity to PVL-positive, methicillin-resistant S. aureus (PVL-MRSA) strains, although three novel spa types and a novel MLST (ST1518) were detected. Furthermore, the detection of PVL phages and haplotypes in PVL-MSSA identical to those previously found in PVL-MRSA isolates highlights the role these strains may play as precursors of emerging lineages of clinical significance. PMID:22718937
Emergence and Dissemination of a Community-Associated Methicillin-Resistant Panton-Valentine Leucocidin-Positive Staphylococcus aureus Clone Sharing the Sequence Type 5 Lineage with the Most Prevalent Nosocomial Clone in the Same Region of Argentina▿
Sola, Claudia; Saka, Hector A.; Vindel, Ana; Bocco, José Luis
Epidemiological surveillance for community-associated methicillin-resistant Staphylococcus aureus revealed prevalences of 33% and 13% in pediatric and adult patients, respectively, in Cordoba, Argentina, in 2005. This study describes for the first time the emergence and dissemination of the sequence type 5 (ST5) lineage as the most prevalent clone (89%) (pulsed-field gel electrophoresis type I-ST5-staphylococcal cassette chromosome type IVa-spa type 311) harboring the Panton-Valentine leukocidin and enterotoxin A genes. PMID:18322068
Full Text Available Staphylococcus aureus is the most common cause of the difficult-to-treat osteomyelitis (OM. To better diagnose and manage S. aureus OM, especially for severe and long duration cases, indicators for risk prediction and severity evaluation are needed. Here, 139 clinical S. aureus isolates from orthopedic infections were divided into OM group (60 isolates from 60 OM patients and non-OM group (79 isolates from 79 non-OM patients. Molecular types, antimicrobial susceptibility, and virulence factor profiles were evaluated and compared between the two groups to identify potential indicators associated with the prevalence of S. aureus OM. Clinical manifestations and laboratory data were analyzed to identify indicators affecting OM duration and severity. We found that some sequence types were specific to OM infection. The pvl, bbp, and ebps genes were associated with S. aureus OM prevalence. The pvl, bbp, and sei genes were associated with relatively longer OM duration. Panton-Valentine leucocidin (PVL-positive S. aureus OM presented more serious inflammatory responses. Our results emphasize the significance of PVL in affecting the prevalence, duration, and severity of S. aureus OM. Diagnosing and monitoring PVL-related S. aureus OM may help direct better prognosis and treatment of these patients.
Full Text Available Panton-Valentine leukocidin (PVL, a bicomponent staphylococcal leukotoxin, is involved in the poor prognosis of necrotizing pneumonia. The present study aimed to elucidate the binding mechanism of PVL and in particular its cell-binding domain. The class S component of PVL, LukS-PV, is known to ensure cell targeting and exhibits the highest affinity for the neutrophil membrane (Kd∼10(-10 M compared to the class F component of PVL, LukF-PV (Kd∼10(-9 M. Alanine scanning mutagenesis was used to identify the residues involved in LukS-PV binding to the neutrophil surface. Nineteen single alanine mutations were performed in the rim domain previously described as implicated in cell membrane interactions. Positions were chosen in order to replace polar or exposed charged residues and according to conservation between leukotoxin class S components. Characterization studies enabled to identify a cluster of residues essential for LukS-PV binding, localized on two loops of the rim domain. The mutations R73A, Y184A, T244A, H245A and Y250A led to dramatically reduced binding affinities for both human leukocytes and undifferentiated U937 cells expressing the C5a receptor. The three-dimensional structure of five of the mutants was determined using X-ray crystallography. Structure analysis identified residues Y184 and Y250 as crucial in providing structural flexibility in the receptor-binding domain of LukS-PV.
Al-haddad, Omaima H; Zorgani, Abdulaziz; Ghenghesh, Khalifa Sifaw
Methicillin-resistant Staphylococcus aureus (MRSA) colonized children are at an increased risk of developing infections than methicillin-sensitive S. aureus colonized children. Nasal specimens from inpatient children, mothers of inpatient children, healthcare workers, and outpatient children at Tripoli Children Hospital (TCH) were examined for MRSA by chromogenic MRSA ID medium. Susceptibility of MRSA isolates to antibiotics was determined by the disc diffusion method. The nasal carriage rate of MRSA among inpatient children (8.3%, 24 of 289), their mothers (11%, 22 of 200), and healthcare workers (12.4%, 22 of 178) was significantly higher than among outpatient children (2.2%, 2 of 91) (P < 0.05, P < 0.02, and P < 0.006, respectively). Of the examined MRSA isolates (N = 35) 10 (28.6%) were positive for Panton-Valentine leucocidin genes by polymerase chain reaction. Multidrug resistance was found in 24.3% (17 of 70) of MRSA isolates. Nasal carriage of multidrug-resistant Panton-Valentine leucocidin-positive MRSA is not uncommon among inpatient children and their mothers in Tripoli.
Garnier, Fabien; Tristan, Anne; François, Bruno; Etienne, Jerome; Delage-Corre, Manuella; Martin, Christian; Liassine, Nadia; Wannet, Wim; Denis, François; Ploy, Marie-Cécile
Necrotizing pneumonia caused by Staphylococcus aureus strains carrying the Panton-Valentin leukocidin gene is a newly described disease entity. We report a new fatal case of necrotizing pneumonia. An S. aureus strain with an agr1 allele and of a new sequence type 377 was recovered, representing a
Full Text Available One key aspect of S. aureus virulence lies in its ability to target the host cell membrane with a large number of membrane-damaging toxins and peptides. In this review, we describe the hemolysins, the bi-component leukocidins, which include the Panton Valentine Leukocidin, LukAB/GH, LukED and the cytolytic peptides (Phenol Soluble Modulins. While at first glance, all these factors might appear redundant, it is now clear that some of these factors play specific roles in certain S. aureus life stages and diseases or target specific cell types or species. Here, we present an update of the literature on toxins receptors and their cell type and species specificities. Furthermore, we review epidemiological studies and animal models illustrating a role of these membrane-damaging factors in various diseases. Finally, we emphasize the interplay of these factors with the host immune system and highlight all their non-lytic functions.
Bartels, Mette Damkjaer; Boye, Kit; Rhod Larsen, Anders
In Copenhagen, methicillin-resistant Staphylococcus aureus (MRSA) accounted for ... by pulsed-field gel electrophoresis, Staphylococcus protein A (spa) typing, multilocus sequence typing, staphylococcal chromosome cassette (SCC) mec typing, and detection of Panton-Valentine leukocidin (PVL) genes. Seventy-one percent of cases were community-onset MRSA (CO-MRSA); of these, 36% had...
Bartels, M D; Kristoffersen, K; Boye, K
The number of patients with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has increased rapidly in Copenhagen, Denmark since 2003. Patients with the typical Panton-Valentine leukocidin-positive CA-MRSA clone ST30-IVc were contacted with the aim of treating MRSA carriers...
Two distinct clones of methicillin-resistant Staphylococcus aureus (MRSA) with the same USA300 pulsed-field gel electrophoresis profile: a potential pitfall for identification of USA300 community-associated MRSA
Larsen, Anders Rhod; Goering, Richard; Stegger, Marc
Analysis of methicillin-resistant Staphylococcus aureus (MRSA) characterized as USA300 by pulsed-field gel electrophoresis identified two distinct clones. One was similar to community-associated USA300 MRSA (ST8-IVa, t008, and Panton-Valentine leukocidin positive). The second (ST8-IVa, t024...
Vandenesch, François; Lina, G.; Henry, Thomas
One key aspect of the virulence of Staphylococcus aureus lies in its ability to target the host cell membrane with a large number of membrane-damaging toxins and peptides. In this review, we describe the hemolysins, the bi-component leukocidins (which include the Panton Valentine leukocidin, LukAB/GH, and LukED), and the cytolytic peptides (phenol soluble modulins). While at first glance, all of these factors might appear redundant, it is now clear that some of these factors play specific roles in certain S. aureus life stages and diseases or target specific cell types or species. In this review, we present an update of the literature on toxin receptors and their cell type and species specificities. Furthermore, we review epidemiological studies and animal models illustrating the role of these membrane-damaging factors in various diseases. Finally, we emphasize the interplay of these factors with the host immune system and highlight all their non-lytic functions. PMID:22919604
Dupieux, C; Blondé, R; Bouchiat, C; Meugnier, H; Bes, M; Laurent, S; Vandenesch, F; Laurent, F; Tristan, A
We describe two cases of human infections caused by Staphylococcus aureus clonal complex (CC) 75, also called Staphylococcus argenteus, harbouring the Panton-Valentine leucocidin (PVL). These two sporadic cases were community-acquired, and identified in France in 2014. Both had an epidemiological link with Mayotte, an overseas department of France located in the Indian Ocean off the south-eastern African coast. This report illustrates that, contrary to previous descriptions, S. argenteus can acquire important virulence factors and be responsible for severe infections.
Coombs, Geoffrey W.; Monecke, Stefan; Ehricht, Ralf; Slickers, Peter; Pearson, Julie C.; Tan, Hui-leen; Christiansen, Keryn J.; O'Brien, Frances G.
Clonal complex 59 (CC59) community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains were characterized using pulsed-field gel electrophoresis, spa typing, multilocus sequence typing, diagnostic DNA microarrays, and PCRs targeting staphylococcal cassette chromosome mec (SCCmec) elements and Panton-Valentine leukocidin (PVL). Six distinct groups within CC59 were characterized. At least seven different variants of SCCmec elements were identified (IVa [2B], IVb [2B], IVd [...
Bettin, Alfonso; Causil, Ceyla; Reyes, Niradiz
Staphylococcus aureus (SA) remains a major cause of nosocomial and community-acquired infections worldwide. Nasal carriage of this bacterium among hospital personnel constitutes an important source for nosocomial infections. A cross-sectional study enrolling the whole medical student population (n=387) of the School of Medicine at the Universidad de Cartagena, Colombia, was conducted to evaluate the carriage rates of both methicillin sensitive- and methicillin resistant-SA, the frequency of Panton-Valentine leukocidin genes in the isolates, and risk factors associated with carriage in this selected population. After signing an informed consent, participants completed a survey related to possible risk factors for colonization, and nasal swabs were collected from anterior nares. Staphylococcus aureus strains isolated from carriers were subjected to DNA extraction and PCR assays to determine the presence of MecA and Panton-Valentine leukocidin genes. Typing of the staphylococcal chromosomal cassette was performed for methicillin resistant strains. Molecular analysis was performed for only one strain per carrier. Prevalence of carriage for methicillin sensitive- and methicillin resistant-SA was 25% and 1.6% respectively. Most of the methicillin resistant isolates carried the staphylococcal chromosomal cassette type IV and the genes for Panton-Valentine leukocidin. To determine carrier types among medical students, each participant was subjected to four additional swabs, each taken two weeks apart. 9.8% persistent carriers, 53.1% intermittent carriers, and 37.1% non-carriers of SA were found. There was no association between risk factors analyzed and carriage of the bacterium. The study was conducted from April to September 2009 and found a persistent carriage of methicillin resistant-SA strains bearing the genes for Panton-Valentine leukocidin among medical students, evidencing the potential contribution of this portion of healthcare personnel either to the spread or
Rouha, Harald; Badarau, Adriana; Visram, Zehra C; Battles, Michael B; Prinz, Bianka; Magyarics, Zoltán; Nagy, Gábor; Mirkina, Irina; Stulik, Lukas; Zerbs, Manuel; Jägerhofer, Michaela; Maierhofer, Barbara; Teubenbacher, Astrid; Dolezilkova, Ivana; Gross, Karin; Banerjee, Srijib; Zauner, Gerhild; Malafa, Stefan; Zmajkovic, Jakub; Maier, Sabine; Mabry, Robert; Krauland, Eric; Wittrup, K Dane; Gerngross, Tillman U; Nagy, Eszter
Staphylococcus aureus is a major human pathogen associated with high mortality. The emergence of antibiotic resistance and the inability of antibiotics to counteract bacterial cytotoxins involved in the pathogenesis of S. aureus call for novel therapeutic approaches, such as passive immunization with monoclonal antibodies (mAbs). The complexity of staphylococcal pathogenesis and past failures with single mAb products represent considerable barriers for antibody-based therapeutics. Over the past few years, efforts have focused on neutralizing α-hemolysin. Recent findings suggest that the concerted actions of several cytotoxins, including the bi-component leukocidins play important roles in staphylococcal pathogenesis. Therefore, we aimed to isolate mAbs that bind to multiple cytolysins by employing high diversity human IgG1 libraries presented on the surface of yeast cells. Here we describe cross-reactive antibodies with picomolar affinity for α-hemolysin and 4 different bi-component leukocidins that share only ∼26% overall amino acid sequence identity. The molecular basis of cross-reactivity is the recognition of a conformational epitope shared by α-hemolysin and F-components of gamma-hemolysin (HlgAB and HlgCB), LukED and LukSF (Panton-Valentine Leukocidin). The amino acids predicted to form the epitope are conserved and known to be important for cytotoxic activity. We found that a single cross-reactive antibody prevented lysis of human phagocytes, epithelial and red blood cells induced by α-hemolysin and leukocidins in vitro, and therefore had superior effectiveness compared to α-hemolysin specific antibodies to protect from the combined cytolytic effect of secreted S. aureus toxins. Such mAb afforded high levels of protection in murine models of pneumonia and sepsis.
Full Text Available Panton-Valentine Leucocidin (PVL, one of the β-barrel pore-forming staphylococcal leucotoxins, is known to be associated to furuncles and some severe community pneumonia. However, it is still uncertain how many other virulence factors are also associated to furuncles and what the risk factors of furuncles are in immuno-compromised status of patients, especially the HIV (+ patients. In this paper, we use antigen immunoprecipitation and multiplex PCR approach to determine the presence of 19 toxins, 8 adhesion factors and the PFGE profiles associated to furuncles in three independent patient study groups of S. aureus (SA isolates collected from the Cayenne General Hospital (French Guiana. The patient groups were made of: 16 isolates from HIV (- patients, 9 from HIV (+ patients suffering from furuncles, and 30 control isolates from patients with diverse secondary infected dermatitis. Our data reveals that the majority (96% of SA strains isolated from HIV patient-derived furuncles significantly produced PVL (p<10(-7, whereas only 10% of SA strains produced this toxin in secondary infected dermatosis. A high prevalence of LukE-LukD-producing isolates (56 to 78% was recorded in patient groups. Genes encoding clumping factor B, collagen- and laminin-binding proteins (clfB, cna, lbp, respectively were markedly frequent (30 to 55%, without being associated to a specific group. Pulse field gel electrophoresis evidenced 24 overall pulsotypes, whereas the 25 PVL-producing isolates were distributed into 15 non clonal fingerprints. These pulsotypes were not specific PVL-producing isolates. PVL appears to be the major virulence factor associated to furuncles in Europe and in South America regardless of the immune status of the HIV patients.
Ruhlmann, Christina H; Kolmos, Hans Jørn J; Kristiansen, Jette E
Recent Dutch studies indicate that methicillin-resistant Staphylococcus aureus (MRSA) sequence type 398 is widely distributed in pigs and may give rise to infection in humans. In this study we present the first two Danish cases of MRSA infection, which in all probability were acquired from...... occupational contact with pigs. One infection presented as a severe surgical wound infection, following knee surgery, the other as a superficial ear lobe infection. Both MRSA strains were multiresistant, sequence type 398, Spa-type t034, and Panton-Valentine leukocidin-encoding gene negative. Udgivelsesdato...
Ahmed S Khairalla; Reham Wasfi; Hossam M Ashour
.... Antibiotic susceptibility, biofilm formation, Staphylococcal protein A (spa) typing, SCCmec typing, and PCR-based assays were used to detect mecA, mecC, vanA, Panton-Valentine Leukocidin toxin (PVL...
Dennis L. Stevens; Yongsheng Ma; Daniel B. Salmi; Eric McIndoo; Randi J. Wallace; Amy E. Bryant
.... The present study investigated the effects that cell-wall active antibiotics and protein-synthesis inhibitors have on transcription and translation of genes for Panton-Valentine leukocidin, alpha...
, 37(74.0%)resistant to only penicillin, 5 to one additional drug with penicillin, and 3 to two-additional drugs. The high prevalence of S.aureus PVL-positive strains posed dire clinical conquences, because co-existence of MRSA strains with ...
Perret, Magali; Badiou, Cédric; Lina, Gérard; Burbaud, Sophie; Benito, Yvonne; Bes, Michèle; Cottin, Vincent; Couzon, Florence; Juruj, Carole; Dauwalder, Olivier; Goutagny, Nadège; Diep, Binh An; Vandenesch, François; Henry, Thomas
Staphylococcus aureus is a major pathogen responsible for both nosocomial and community-acquired infections. Central to its virulence is its ability to secrete haemolysins, pore-forming toxins and cytolytic peptides. The large number of membrane-damaging toxins and peptides produced during S. aureus infections has hindered a precise understanding of their specific roles in diseases. Here, we used comprehensive libraries of recombinant toxins and synthetic cytolytic peptides, of S. aureus mutants and clinical strains to investigate the role of these virulence factors in targeting human macrophages and triggering IL-1β release. We found that the Panton Valentine leukocidin (PVL) is the major trigger of IL-1β release and inflammasome activation in primary human macrophages. The cytolytic peptides, δ-haemolysin and PSMα3; the pore-forming toxins, γ-haemolysin and LukDE; and β-haemolysin synergize with PVL to amplify IL-1β release, indicating that these factors cooperate with PVL to trigger inflammation. PVL(+) S. aureus causes necrotizing pneumonia in children and young adults. The severity of this disease is due to the massive recruitment of neutrophils that cause lung damage. Importantly, we demonstrate that PVL triggers IL-1β release in human alveolar macrophages. Furthermore, IL-1β released by PVL-intoxicated macrophages stimulates the secretion of the neutrophil attracting chemokines, IL-8 and monocyte chemotactic protein-1, by lung epithelial cells. Finally, we show that PVL-induced IL-8/monocyte chemotactic protein-1 release is abolished by the inclusion of IL-1 receptor antagonist (IL-1Ra) in a mixed culture of lung epithelial cells and macrophages. Together, our results identify PVL as the predominant S. aureus secreted factor for triggering inflammasome activation in human macrophages and demonstrate how PVL-intoxicated macrophages orchestrate inflammation in the lung. Finally, our work suggests that anakinra, a synthetic IL-1Ra, may be an effective
Full Text Available Abstract Introduction Staphylococcus aureus has emerged as a major nosocomial pathogen in the last decades and also represents the second most common pathogen isolated from patients in outpatient settings. Although methicillin-resistant S.aureus infections were traditionally limited to hospitals, community-associated cases of methicillin-resistant S.aureus infections have been reported. In our case, we observed an unexpected event during treatment. Case presentation A 60-year-old Caucasian man developed fever and multiple muscle and brain abscesses caused by Panton-Valentine leukocidin-negative community-associated methicillin-resistant S. aureus. Conclusion Although our patient was given antimicrobials active against the isolated methicillin-resistant S. aureus strain, it was only after the introduction of daptomycin that his skin, soft tissue and muscle lesions and also brain manifestations improved.
Full Text Available Staphylococcus aureus and coagulase-negative Staphylococcus (CoNS are frequently found in nosocomial environments as the main pathogen in several infections. In 1961, reports of nosocomial S. aureus resistant to methicillin, the drug of choice against penicillin-resistant strains, required new alternatives and vancomycin started being used to treat infections caused by methicillin-resistant S. aureus (MRSA. Community-acquired methicillin-resistant S. aureus (CA-MRSA was first reported in 1990 affecting patients without risk factors for infection with MRSA of hospital origin. MRSA of community origin harbor the genes responsible for the synthesis of Panton-Valentine leukocidin (PVL, a toxin associated with skin and soft tissue infections and that carries the staphylococcal cassette chromosome mec (SCCmec type IV. CA-MRSA emergence has caused great impact on the worldwide medical community since the presence of this pathogen in patients without risk factors represents a high risk to public health.
Zimmermann-Meisse, Gaëlle; Prévost, Gilles; Jover, Emmanuel
Various membrane receptors associated with the innate immune response have recently been identified as mediators of the cellular action of Staphylococcus aureus leucotoxins. Two of these, the Panton-Valentine leucotoxin LukS-PV/LukF-PV and the γ-hemolysin HlgC/HlgB, bind the C5a complement-derived peptide receptor. These leucotoxins utilize the receptor to induce intracellular Ca 2+ release from internal stores, other than those activated by C5a. The two leucotoxins are internalized with the phosphorylated receptor, but it is unknown whether they divert retrograde transport of the receptor or follow another pathway. Immunolabeling and confocal microscopic techniques were used to analyze the presence of leucotoxins in endosomes, lysosomes, endoplasmic reticulum, and Golgi. The two leucotoxins apparently followed retrograde transport similar to that of the C5a peptide-activated receptor. However, HlgC/HlgB reached the Golgi network very early, whereas LukS-PV/LukF-PV followed slower kinetics. The HlgC/HlgB leucotoxin remained in neutrophils 6 h after a 10-min incubation of the cells in the presence of the toxin with no signs of apoptosis, whereas apoptosis was observed 3 h after neutrophils were incubated with LukS-PV/LukF-PV. Such retrograde transport of leucotoxins provides a novel understanding of the cellular effects initiated by sublytic concentrations of these toxins.
Full Text Available Staphylococcus aureus (S. aureus is a human commensal and an opportunistic pathogen that may affect the gastrointestinal tract, the heart, bones, skin or the respiratory tract. S. aureus is frequently involved in hospital- or community-acquired lung infections. The pathogenic potential is associated with its ability to secrete highly effective virulence factors. Among these, the pore-forming toxins Panton-Valentine leukocidin (PVL and hemolysin A (Hla are the important virulence factors determining the prognosis of pneumonia cases. This review focuses on the structure and the functions of S. aureus hemolysin A and its sub-lethal effects on airway epithelial cells. The hypothesis is developed that Hla may not just be a tissue-destructive agent providing the bacteria with host-derived nutrients, but may also play complex roles in the very early stages of interactions of bacteria with healthy airways, possibly paving the way for establishing acute infections.
Suhaili, Zarizal; Lean, Soo-Sum; Mohamad, Noor Muzamil; Rachman, Abdul R Abdul; Desa, Mohd Nasir Mohd; Yeo, Chew Chieng
Most of the efforts in elucidating the molecular relatedness and epidemiology of Staphylococcus aureus in Malaysia have been largely focused on methicillin-resistant S. aureus (MRSA). Therefore, here we report the draft genome sequence of the methicillin-susceptible Staphylococcus aureus (MSSA) with sequence type 1 (ST1), spa type t127 with Panton-Valentine Leukocidin (pvl) pathogenic determinant isolated from pus sample designated as KT/314250 strain. The size of the draft genome is 2.86 Mbp with 32.7% of G + C content consisting 2673 coding sequences. The draft genome sequence has been deposited in DDBJ/EMBL/GenBank under the accession number AOCP00000000.
Rivera, José O; Ho, Hoi; Domínguez, Delfina C; Tyroch, Alan H; Antony, Suresh; Norte, Arturo; Pérez-Ruvalcaba, José Ascensión
El Paso, Texas and Ciudad Juarez, Mexico comprise the largest U.S./Mexico border population. Bacterial samples were collected from two hospitals in El Paso and two in Ciudad Juarez and transported to a reference microbiology laboratory in El Paso for microbial identification and antimicrobial susceptibility testing according to NCCLS standards. The presence of the MecA gene, and the prevalence of both the SSCmec IV element and the Panton-Valentine leukocidin were investigated by PCR in all MRSA isolates. A total of 201 isolates in El Paso and 128 in Ciudad Juarez of Staphylococcus aureus were identified, of those, MRSA were significantly more prevalent in El Paso than in Ciudad Juarez [89 (44.3%) versus 10 (7.8%) respectively (pCiudad Juarez.
Holzknecht, B.J.; Hardardottir, H.; Haraldsson, Gustav Helgi
, and screening for the Panton-Valentine leukocidin (PVL) gene. Two hundred twenty-six infected (60%) or colonized (40%) individuals were detected (annual incidence 2.5 to 16/100,000). From 2000 to 2003, two health care-associated outbreaks dominated (spa types t037 and t2802), which were successfully controlled...... with extensive infection control measures. After 2004, an increasing number of community-associated (CA) cases without relation to the health care system occurred. A great variety of clones (40 PFGE types and 49 spa types) were found, reflecting an influx of MRSA from abroad. The USA300 and Southwest Pacific......The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) is continuously changing. Iceland has a low incidence of MRSA. A "search and destroy" policy (screening patients with defined risk factors and attempting eradication in carriers) has been implemented since 1991. Clinical...
Bartels, Mette Damkjaer; Boye, Kit; Rhod Larsen, Anders
by pulsed-field gel electrophoresis, Staphylococcus protein A (spa) typing, multilocus sequence typing, staphylococcal chromosome cassette (SCC) mec typing, and detection of Panton-Valentine leukocidin (PVL) genes. Seventy-one percent of cases were community-onset MRSA (CO-MRSA); of these, 36% had...
Bartels, Mette Damkjær; Boye, Kit; Larsen, Anders Rhod
by pulsed-field gel electrophoresis, Staphylococcus protein A (spa) typing, multilocus sequence typing, staphylococcal chromosome cassette (SCC) mec typing, and detection of Panton-Valentine leukocidin (PVL) genes. Seventy-one percent of cases were community-onset MRSA (CO-MRSA); of these, 36% had...
Feltrin, Fabiola; Alba, Patricia; Kraushaar, Britta
Pandemic methicillin-resistant Staphylococcus aureus (MRSA) clonal complex 97 (CC97) lineages originated from livestock-to-human host jumps. In recent years, CC97 has become one of the major MRSA lineages detected in Italian farmed animals. The aim of this study was to characterize and analyze...... by macrorestriction pulsed-field gel electrophoresis (PFGE) analysis, multilocus sequence typing (MLST), spa typing, staphylococcal cassette chromosome mec (SCCmec) typing, and antimicrobial resistance pattern analysis. Virulence and resistance genes were investigated by PCR and microarray analysis. Most...... Panton-Valentine leukocidin (PVL) negative, and a few (n = 7) tested positive for sak or scn. All MRSA isolates were multidrug resistant (MDR), and the main features were erm(B)- or erm(C)-mediated (n = 18) macrolide-lincosamide-streptogramin B resistance, vga(A)-mediated (n = 37) pleuromutilin...
Claudio Querido Fortes
Full Text Available We report here the first case of endocarditis due to CA-MRSA not associated with healthcare contact in Brazil in Brazil. A previously healthy patient presented with history of endocarditis following a traumatic wound infection. Patient had multiple positive blood cultures within 72 h of admission and met modified Duke's criterion for infective endocarditis. The isolate was typed as Staphylococcal cassette chromosome (SCC mec type IV and was positive for presence of Panton-Valentine leukocidin (PVL. Increased incidence of CA-MRSA endocarditis is a challenge for the internist to choose the best empirical therapy. Several authors have suggested an empirical therapy with both a beta-lactam and an anti-MRSA agent for serious S. aureus infections. Our patient was treated with Vancomycin and made complete recovery in 3 months.
Edslev, Sofie Marie; Westh, Henrik Torkil; Andersen, Paal Skytt
of the CC80 S. aureus lineage was conducted from whole-genome sequences of 217 isolates (23 MSSA and 194 MRSA) from 22 countries. All isolates were further genetically characterized in regard to resistance determinants and PVL carriage, and epidemiological data was obtained for selected isolates. RESULTS......OBJECTIVES: Community-acquired MRSA (CA-MRSA) isolates belonging to clonal complex 80 (CC80) are recognized as the European CA-MRSA. The prevailing European CA-MRSA clone carries a type IVc staphylococcal cassette chromosome mec (SCCmec) and expresses Panton-Valentine leukocidin (PVL). Recently......, a significant increase of PVL-negative CC80 MRSA has been observed in Denmark. The aim of this study was to examine the genetics and the epidemiology of these, and to compare them to the European CA-MRSA clone in order to understand the emergence of PVL-negative CC80 MRSA. METHODS: Phylogenetic analysis...
Vrieling, M.; Koymans, K.J.; Heesterbeek, D.A.C.; Aerts, P.C.; Rutten, V.P.M.G.|info:eu-repo/dai/nl/092848028; de Haas, C.J.C.; van Kessel, K.P.M.; Koets, A.P.|info:eu-repo/dai/nl/194306992; Nijland, R; van Strijp, J.A.G.
Although Staphylococcus aureus is best known for infecting humans, bovine-specific strains are a major cause of mastitis in dairy cattle. The bicomponent leukocidin LukMF′, exclusively harbored by S. aureus of ruminant origin, is a virulence factor associated with bovine infections. In this study,
Kassis, Christelle; Hachem, Ray; Raad, Issam I; Perego, Cheryl A; Dvorak, Tanya; Hulten, Kristina G; Frenzel, Elizabeth; Thomas, Georgia; Chemaly, Roy F
The incidence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) soft tissue infections is rising. However, CA-MRSA outbreaks among health care workers (HCWs) are rarely reported. We describe 3 clusters of CA-MRSA soft tissue infections among HCWs and the subsequent transmission to a patient. The first cluster of boils occurred in 4 employees who worked in the ambulatory treatment clinic (area A) and 1 patient (PA1) who frequently visited area A. Three employees (EA1, EA2, and EA3) and PA1 had positive cultures. Twelve employees in 2 geographically separate diagnostic imaging areas (areas B and C) reported recent or current boils of whom EB1, EB2, EB3, and EC1 had positive cultures. Molecular subtyping using pulse-field gel electrophoresis (PFGE) was performed on all 8 isolates and confirmed by the Centers for Disease Control and Prevention laboratory. Relatedness of the MRSA strain was confirmed by PFGE in 7 of 8 isolates. Only EB3 was not related to the prototype CA-MRSA strain. All 7 related MRSA strains contained the typical genetic organization of staphylococcal cassette chromosome (SCC)-mec type IVa plus genes encoding Panton-Valentine Leukocidin. EB3's strain contained SCC-mec type II and was Panton-Valentine Leukocidin negative. A total of 171 questionnaires was sent. Nine of the 85 HCWs who responded reported a recent or current history of boils. Infection control conducted an education program for employees in areas A, B, and C. Early identification and control of CA-MRSA infections among HCWs is important to limit horizontal transmission to patients. Future efforts should include educational programs and guidelines for reporting and treating HCWs with MRSA infections. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.
Gouaux, E.; Hobaugh, M.; Song, L.
alpha-Hemolysin from Staphylococcus aureus assembles from a water-soluble, monomeric species to a membrane-bound heptamer on the surface of target cells, creating water-filled channels that lead to cell death and lysis. Staphylococcus aureus also produces the gamma-hemolysin and leukocidin toxins, which function as two component toxins in the disruption and lysis of erythrocytes and leukocytes. Analysis of the aligned sequences of alpha-hemolysin, gamma-hemolysin, and leukocidin in the contex...
Jans, Christoph; Merz, Axel; Johler, Sophia; Younan, Mario; Tanner, Sabine A; Kaindi, Dasel Wambua Mulwa; Wangoh, John; Bonfoh, Bassirou; Meile, Leo; Tasara, Taurai
Staphylococcus aureus frequently isolated from milk products in sub-Saharan Africa (SSA) is a major pathogen responsible for food intoxication, human and animal diseases. SSA hospital-derived strains are well studied but data on the population structure of foodborne S. aureus required to identify possible staphylococcal food poisoning sources is lacking. Therefore, the aim was to assess the population genetic structure, virulence and antibiotic resistance genes associated with milk-derived S. aureus isolates from Côte d'Ivoire, Kenya and Somalia through spa-typing, MLST, and DNA microarray analysis. Seventy milk S. aureus isolates from the three countries were assigned to 27 spa (7 new) and 23 (12 new) MLST sequence types. Milk-associated S. aureus of the three countries is genetically diverse comprising human and livestock-associated clonal complexes (CCs) predominated by the CC5 (n = 10) and CC30 (n = 9) isolates. Panton-Valentine leukocidin, toxic shock syndrome toxin and enterotoxin encoding genes were predominantly observed among human-associated CCs. Penicillin, fosfomycin and tetracycline, but not methicillin resistance genes were frequently detected. Our findings indicate that milk-associated S. aureus in SSA originates from human and animal sources alike highlighting the need for an overarching One Health approach to reduce S. aureus disease burdens through improving production processes, animal care and hygienic measures. Copyright © 2017 Elsevier Ltd. All rights reserved.
Thapaliya, Dipendra; Dalman, Mark; Kadariya, Jhalka; Little, Katie; Mansell, Victoria; Taha, Mohammed Y; Grenier, Dylan; Smith, Tara C
Staphylococcus aureus can colonize a range of species. Although numerous studies have isolated pathogenic bacteria from wild birds, very little is known regarding S. aureus and their potential to spread methicillin-resistant (MRSA) strains. The objective of this study was to determine the presence and molecular characteristics of S. aureus in geese fecal samples collected from ten state parks across Northeast Ohio (NEO). A total of 182 fecal samples from Canada geese (Branta canadensis) were collected in April 2015. Isolates were characterized using multi-locus sequence (MLST) and spa typing, as well as PCR to detect the presence of Panton-Valentine leukocidin (PVL), mecA, and scn genes. Antibiotic susceptibility testing was done via Vitek-2 system. The overall contamination by S. aureus in fecal samples was 7.1% (13/182); 7/182 (3.8%) were MRSA and 6/182 (3.3%) were methicillin-susceptible S. aureus (MSSA). One isolate was positive for PVL. A total of eight different spa types were observed. MLST included ST5, ST8, ST291, ST298, and ST2111. One (7.7%) MSSA isolate was multi-drug resistant. The S. aureus contamination in NEO state parks ranged from 0% (park 1, 4, 8, 9) to 35% (7/20) (park 5). Parks 2, 3, 6, and 7 had 5% (1/20) positive. The results of this study indicate that the feces of geese collected at various state parks in NEO may harbor S. aureus.
Full Text Available It has been shown previously that high rates of methicillin- and mupirocin-resistant Staphylococcus aureus exist in the Caribbean islands of Trinidad and Tobago, as well as a high prevalence of Panton-Valentine leukocidin-positive S. aureus. Beyond these studies, limited typing data have been published. In order to obtain insight into the population structure not only of MRSA but also of methicillin-susceptible S. aureus, 294 clinical isolates collected in 2012/2013 were typed by microarray hybridisation. A total of 15.31% of the tested isolates were MRSA and 50.00% were PVL-positive. The most common MSSA strains were PVL-positive CC8-MSSA (20.41% of all isolates tested, PVL-positive CC152-MSSA (9.52% and PVL-positive CC30-MSSA (8.84% while the most common MRSA were ST239-MRSA-III&SCCmer (9.18% and ST8-MRSA-IV, "USA300" (5.78%. 2.38% of characterised isolates belonged to distinct strains likely to be related to "Staphylococcus argenteus" lineages. The population structure of S. aureus isolates suggests an importation of strains from Africa, endemicity of PVL-positive MSSA (mainly CC8 and of ST239-MRSA-III, and a recent emergence of the PVL-positive CC8-MRSA-IV strain "USA300".
Monecke, Stefan; Stieber, Bettina; Roberts, Rashida; Akpaka, Patrick Eberechi; Slickers, Peter; Ehricht, Ralf
It has been shown previously that high rates of methicillin- and mupirocin-resistant Staphylococcus aureus exist in the Caribbean islands of Trinidad and Tobago, as well as a high prevalence of Panton-Valentine leukocidin-positive S. aureus. Beyond these studies, limited typing data have been published. In order to obtain insight into the population structure not only of MRSA but also of methicillin-susceptible S. aureus, 294 clinical isolates collected in 2012/2013 were typed by microarray hybridisation. A total of 15.31% of the tested isolates were MRSA and 50.00% were PVL-positive. The most common MSSA strains were PVL-positive CC8-MSSA (20.41% of all isolates tested), PVL-positive CC152-MSSA (9.52%) and PVL-positive CC30-MSSA (8.84%) while the most common MRSA were ST239-MRSA-III&SCCmer (9.18%) and ST8-MRSA-IV, "USA300" (5.78%). 2.38% of characterised isolates belonged to distinct strains likely to be related to "Staphylococcus argenteus" lineages. The population structure of S. aureus isolates suggests an importation of strains from Africa, endemicity of PVL-positive MSSA (mainly CC8) and of ST239-MRSA-III, and a recent emergence of the PVL-positive CC8-MRSA-IV strain "USA300".
Full Text Available Staphylococcus aureus is a part of the microbiota flora in many animal species. The clonal spread of S. aureus among animals and personnel in a Zoological Park was investigated. Samples were collected from colonized and infected sites among 32 mammals, 11 birds and eight humans. The genes mecA, mecC, lukF/lukS-PV (encoding Panton-Valentine leukocidin, PVL and tst (toxic shock syndrome toxin-1 were investigated by PCR. Clones were defined by Multilocus Sequence Typing (MLST, spa type and Pulsed-Field Gel Electrophoresis (PFGE. Seven S. aureus isolates were recovered from four animals and one from an employee. All were mecA, mecC and tst–negative, whereas, one carried the PVL genes and was isolated from an infected Squirrel monkey. Clonal analysis revealed the occurrence of seven STs, eight PFGE and five spa types including ones of human origin. Even though a variety of genotypes were identified among S. aureus strains colonizing zoo park residents, our results indicate that colonization with human lineages has indeed occurred.
McCarthy, Alex J; Witney, Adam A; Lindsay, Jodi A
Staphylococcus aureus is a major cause of human and animal infections. Bacteriophage are a class of mobile genetic element (MGE) that carry virulence genes and disseminate them horizontally, including Panton-Valentine leukocidin (PVL), the immune evasion cluster (IEC) associated with human specificity, and enterotoxin A the major toxin associated with food poisoning. S. aureus isolates group into major clonal complex (CC) lineages that largely evolve independently due to possession of different restriction-modification (RM) systems. We aimed to better understand the horizontal and vertical transmission dynamics of virulence and resistance genes by bacteriophage by using (i) bioinformatic approaches to analyze bacteriophage genomes from the first 79 sequenced S. aureus isolates and (ii) S. aureus microarrays to analyze the distribution of bacteriophage and virulence genes in S. aureus isolates from a broader range of lineages. The distribution of eight bacteriophage families was highly variable but lineage associated. Nevertheless, there was evidence of frequent acquisition and loss and not just vertical transmission. Most bacteriophage genes were dispensable, and extensive mosaicism was seen. Surprisingly, virulence genes were tightly associated with specific phage families. This data suggests S. aureus bacteriophage evolve rapidly, and the horizontal gene transfer (HGT) of virulence genes encoded by bacteriophage is restricted by bacteriophage family and the lineage of the host bacterium, delaying the evolution of fully resistant and virulent strains.
Full Text Available Objective:Methicillin-resistant Staphylococcus aureus (MRSA widely distributed in hospitals around the world. There is strong relationship between disease development and S. aureus nasal carriage. The aim of this study was to evaluate the prevalence and epidemiology of nasal colonization with S. aureus and MRSA in the community of Duhok city, Iraq. Methods: 489 students aged 16 to18 years were included. Nasal swab samples were collected followed by antimicrobial susceptibility test. MRSA isolates were selected and investigated for the mecA gene. Also the prevalence of PantonValentine Leukocidin (PVL gene was also studied. Results: A total of 90 (18.4% out of 489 (18.4% of the students were found to be colonized by S. aureus . Only 10 (2.04% of the students were found to be MRSA carrier. All MRSA isolates were sensitive to Vancomycin. PLV gene was detected in one MRSA strain. Conclusion: This is the first study investigating S. aureus colonization in students in the Duhok city. Nasal carriage of S. aureus and MRSA is comparable with reports from elsewhere. Fortunately, all trains included in our study were sensitive to vancomycin. Further research is needed to examine the SCCmec elements and the evolution of MRSA over the time. J Microbiol Infect Dis 2014;4(2: 59-63
Rosenthal, Marnie E; Mediavilla, Jose; Chen, Liang; Sonnenfeld, Julian; Pierce, Logan; Shannon, Alexander; Boucher, Helen; Pearlmutter, Mark; Kreiswirth, Barry; Kuo, Yen-Hong; Previl, Harold; Rojtman, Albert
Knowledge of nasal carriage is important in predicting staphylococcal infection, and no information exists regarding the endemicity of Staphylococcus aureus in Haiti. We performed a cross-sectional analysis of S. aureus nasal screening in an acute care, a subacute rehabilitation, and a community setting, with a brief medical and epidemiological history. PCR-positive S. aureus screening nasal cultures underwent molecular analysis for spa type, SCCmec type, and virulence genes (Panton-Valentine leukocidin (PVL), toxic shock syndrome toxin (TSST), and arginine catabolic mobile element (ACME)), and were evaluated for antibiotic susceptibility using commercial tests. Overall carriage rates of 8.4% methicillin-susceptible S. aureus (MSSA) and 2.8% methicillin-resistant S. aureus (MRSA) were identified, with a high rate of tetracycline resistance. TSST and PVL genes were identified in MSSA. MRSA isolates contained no virulence markers. Unique MSSA phenotypes (i.e., linezolid-resistant, vancomycin-sensitive/daptomycin non-susceptible) were identified, as were two PVL-positive ST152 MSSA colonization isolates, previously geographically limited to Africa. We found a low S. aureus carriage rate with complete vancomycin susceptibility and high tetracycline resistance, which has important public health implications with regard to treatment. Additionally, the finding of PVL-positive MSSA isolates, including the expansion of a previously described limited 'divergent' clone, ST152, warrants further evaluation. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.
Durupt, F; Mayor, L; Bes, M; Reverdy, M-E; Vandenesch, F; Thomas, L; Etienne, J
The precise role of Staphylococcus aureus toxins and nasal carriage in common skin infections remains unclear. To seek correlations between toxin expression, S. aureus nasal carriage and clinical manifestations in patients with community-acquired furuncles and impetigo. From November 2004 to August 2005, we studied clinical data and bacteriological samples prospectively collected from 121 patients presenting with furuncles or impetigo. Sixty-four patients (31 with furuncles and 33 with impetigo) had S. aureus-positive skin culture. Panton-Valentine leukocidin (PVL) genes were present in 13 of 31 (42%) isolates from furuncles and were associated with epidemic furunculosis. Exfoliative toxin genes were present in 10 of 10 (100%) and 12 of 21 (57%) bullous and nonbullous impetigo isolates, respectively. Nasal carriage of S. aureus was found in 58% of patients overall. It was strongly associated with chronic furunculosis but not with simple furuncles (88% vs. 29%, P impetigo are associated with exfoliative toxins. Staphylococcus aureus nasal carriage is associated with the chronicity of furuncles.
Agabou, Amir; Ouchenane, Zouleikha; Ngba Essebe, Christelle; Khemissi, Salim; Chehboub, Mohamed Tedj Eddine; Chehboub, Ilyes Bey; Sotto, Albert; Dunyach-Remy, Catherine; Lavigne, Jean-Philippe
The spread of toxinogenic Staphylococcus aureus is a public health problem in Africa. The objectives of the study were to investigate the rate of S. aureus nasal carriage and molecular characteristics of these strains in livestock and humans in three Algerian provinces. Nasal samples were collected from camels, horses, cattle, sheep and monkeys, as well as humans in contact with them. S. aureus isolates were genotyped using DNA microarray. The rate of S. aureus nasal carriage varied between species: camels (53%), humans and monkeys (50%), sheep (44.2%), horses (15.2%) and cattle (15%). Nine methicillin-resistant S. aureus (MRSA) isolates (7.6%) were identified, isolated from camels and sheep. The S. aureus isolates belonged to 15 different clonal complexes. Among them, PVL+ (Panton-Valentine Leukocidin) isolates belonging to ST80-MRSA-IV and ST152-MSSA were identified in camels (n = 3, 13%) and sheep (n = 4, 21.1%). A high prevalence of toxinogenic animal strains was noted containing TSST-1- (22.2%), EDINB- (29.6%) and EtD- (11.1%) encoding genes. This study showed the dispersal of the highly human pathogenic clones ST152-MSSA and ST-80-MRSA in animals. It suggests the ability of some clones to cross the species barrier and jump between humans and several animal species.
Gonzalez, Alice Gonçalves Martins; Marques, Leila Márcia Peres; Gomes, Marcel da Silva Amorim; Beltrão, Jhonathan Campos do Couto; Pinheiro, Marcos Gabriel; Esper, Luciana Maria Ramires; Paula, Geraldo Renato de; Teixeira, Lenise Arneiro; Aguiar-Alves, Fábio
This study aimed to investigate classical enterotoxin (sea to see) and mecA genes, by polymerase chain reaction and anitimicrobial susceptibility, by disk diffusion test of Staphylococcus aureus isolated from minas frescal cheese (MFC). All methicillin-resistant S. aureus (MRSA) isolates were investigated for the presence of Panton-Valentine leukocidin (PVL) genes and clonal diversity. Thirty-one S. aureus were isolated from four MFC samples. Seven (22.6%) S. aureus carried mecA gene and two of them carried enterotoxin genes seb/sec and sea/seb. Five (16.1%) S. aureus isolates showed induced resistance to clindamycin and nine (29%) were resistant to multiple -antibiotics (MDR), among these, six were MRSA. No MRSA isolates presented the PVL genes. Four MRSA were grouped into three clones and three isolates were not typable by pulsed field gel electrophoresis. MRSA isolates showed, by multilocus sequence typing, sequence types ST1, ST5, ST72 and ST4304 (new ST) and S. aureus protein A (spa type) t127, t568 and t2703. These data suggest that MFC may constitute a risk to the consumer because of its potential for staphylococcal food poisoning; however it might, also, become one of MRSA and MDR strains disseminator, including clones usually found in the hospital environment. © FEMS 2017. All rights reserved. For permissions, please e-mail: email@example.com.
Fogarty, Lisa R.; Haack, Sheridan K.; Johnson, Heather E.; Brennan, Angela K.; Isaacs, Natasha M.; Spencer, Chelsea
Methicillin-resistant Staphylococcus aureus (MRSA) are a threat to human health worldwide, and although detected at marine beaches, they have been largely unstudied at freshwater beaches. Genes indicating S. aureus (SA; femA) and methicillin resistance (mecA) were detected at 11 and 12 of 13 US Great Lakes beaches and in 18% or 27% of 287 recreational water samples, respectively. Eight beaches had mecA + femA (potential MRSA) detections. During an intensive study, higher bather numbers, staphylococci concentrations, and femA detections were found in samples collected after noon than before noon. Local population density, beach cloud cover, and beach wave height were significantly correlated with SA or MRSA detection frequency. The Panton-Valentine leukocidin gene, associated with community-acquired MRSA, was detected in 12 out of 27 potential MRSA samples. The femA gene was detected less frequently at beaches that met US enterococci criteria or EU enterococci ‘excellent’ recreational water quality, but was not related to Escherichia coli-defined criteria. Escherichia coli is often the only indicator used to determine water quality at US beaches, given the economic and healthcare burden that can be associated with infections caused by SA and MRSA, monitoring of recreational waters for non-fecal bacteria such as staphylococci and/or SA may be warranted.
Tsironi Evangelia E
Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus is a serious cause of morbidity and mortality in hospital environment, but also, lately, in the community. This case report is, to our knowledge, the first detailed description of a community-associated methicillin-resistant S. aureus ST80 orbital cellulitis in a previously healthy neonate. Possible predisposing factors of microbial acquisition and treatment selection are also discussed. Case presentation A 28-day-old Caucasian boy was referred to our hospital with the diagnosis of right orbital cellulitis. His symptoms included right eye proptosis, periocular edema and redness. Empirical therapy of intravenous daptomycin, rifampin and ceftriaxone was initiated. The culture of pus yielded a methicillin-resistant S. aureus isolate and the molecular analysis revealed that it was a Panton-Valentine leukocidine-positive ST80 strain. The combination antimicrobial therapy was continued for 42days and the infection was successfully controlled. Conclusions Clinicians should be aware that young infants, even without any predisposing condition, are susceptible to orbital cellulitis caused by community-associated methicillin-resistant S. aureus. Prompt initiation of the appropriate empirical therapy, according to the local epidemiology, should successfully address the infection, preventing ocular and systemic complications.
Full Text Available Autosomal dominant hyper IgE syndrome (AD-HIES is a primary immunodeficiency caused by a loss-of-function mutation in the Signal Transducer and Activator of Transcription 3 (STAT3. This immune disorder is clinically characterized by increased susceptibility to cutaneous and sinopulmonary infections, in particular with Candida and Staphylococcus aureus. It has recently been recognized that the skin microbiome of patients with AD-HIES is altered with an overrepresentation of certain Gram-negative bacteria and Gram-positive staphylococci. However, these alterations have not been characterized at the species- and strain-level. Since S. aureus infections are influenced by strain-specific expression of virulence factors, information on colonizing strain characteristics may provide insights into host-pathogen interactions and help guide management strategies for treatment and prophylaxis. The aim of this study was to determine whether the immunodeficiency of AD-HIES selects for unique strains of colonizing S. aureus. Using multi-locus sequence typing (MLST, protein A (spa typing, and PCR-based detection of toxin genes, we performed a detailed analysis of the S. aureus isolates (n = 13 found on the skin of twenty-one patients with AD-HIES. We found a low diversity of sequence types, and an abundance of strains that expressed methicillin resistance, Panton-Valentine leukocidin (PVL, and staphylococcal enterotoxins K and Q (SEK, SEQ. Our results indicate that patients with AD-HIES may often carry antibiotic-resistant strains that harbor key virulence factors.
Washington, Michael A; Agee, Willie A; Kajiura, Lauren; Staege, Catherine M; Uyehara, Catherine Ft; Barnhill, Jason C
Staphylococcus aureus (S. aureus) is a major cause of morbidity in the military health care setting. Culture-based methods are the most common means of identifying infections caused by this agent. However, culture-based methods lack sensitivity and specificity. The Abbott PLEX-ID instrument uses a combination of the polymerase chain reaction and mass spectrometry for the identification of bacterial isolates. We investigated whether the Abbott PLEX-ID system could identify S. aureus in clinical material and facilitate the epidemiological analysis of individual isolates. The PLEX-ID system positively identified 100% of isolates previously found to be methicillin resistant S. aureus by culture. In addition, analysis using the PLEX-ID software revealed that the majority of S. aureus isolates at Tripler Army Medical Center derive from clonal complex 8 and nearly 100% of these strains express the R-variant of the Panton-Valentine leukocidin virulence factor. These results demonstrate the utility of the PLEX-ID system in identifying clinical isolates and reveal an unexpected level of homogeneity among clinical S. aureus isolates recovered at Tripler Army Medical Center. These results also demonstrate the utility of the PLEX-ID system in identifying the resistance patterns, predicting the virulence properties, and tracking the migration of bacterial pathogens in the clinical setting. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.
Wang, Hong-Kai; Huang, Chun-Yen; Huang, Yhu-Chering
Since first reported in 2002, the rate of methicillin-resistant Staphylococcus aureus (MRSA) among childhood community-associated (CA) S. aureus infection in Taiwan increased significantly up to 2005. There have been no reports on this issue since then. We prospectively collected clinical S. aureus isolates from the patients MRSA were further characterized by pulsed-field gel electrophoresis, staphylococcal cassette chromosome (SCCmec) typing, and multilocus sequence typing. A total of 409 S. aureus isolates were included, and 260 (63.6%) were MRSA. The proportion of MRSA among all S. aureus isolates in 2012 increased significantly (p MRSA isolates, 86.2% were identified from pus or wound. Nine pulsotypes were identified with two major types (type D, 119 (65.7%); type C, 27 (14.9%). Most of the isolates carried either SCCmec IV (66 isolates, 36%) or V T (112 isolates, 62%). 128 isolates (71%) carried Panton-Valentine leukocidin (PVL) genes. Clonal complex (CC) 59 accounted for 146 isolates (80.7%) of two major pulsotypes, CC45 for 19 isolates, ST30 for 6 isolates and ST8 (USA 300) for 4 isolates. In addition to penicillin (100%), most isolates were resistant to erythromycin (81%) and clindamycin (79.3%). Around two-thirds of childhood community-associated S. aureus infections in northern Taiwan were MRSA. Though CC59 is still the prevalent community clone, several new clones emerged in northern Taiwan.
Monecke, Stefan; Müller, Elke; Dorneanu, Olivia Simona; Vremeră, Teodora; Ehricht, Ralf
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.
Full Text Available We performed a cohort study to analyze the virulome of Staphylococcus aureus from the Democratic Republic of the Congo using whole genome sequencing and to assess its impact on the course of S. aureus infections. Community-associated S. aureus from nasal colonization (n = 100 and infection (n = 86 were prospectively collected. Phenotypic susceptibility testing and WGS was done for each isolate. WGS data were used to screen for 79 different virulence factors and for genotyping purposes (spa typing, multilocus sequence typing. The majority of the 79 virulence factors were equally distributed among isolates from colonization and infection. Panton-Valentine leukocidin (PVL and the non-truncated hemolysin β were associated with skin and soft tissue infection (SSTI and recurrence of disease but did not influence the course of infection (i.e., mortality, surgical intervention. For the first time, we show that not only PVL but also hemolysin β could contribute to the development of SSTI in PVL-endemic areas such as Africa.
Thapaliya, Dipendra; O'Brien, Ashley M; Wardyn, Shylo E; Smith, Tara C
The present study was performed to characterize the epidemiology of necrotizing soft tissue infection caused by Streptococcus pyogenes (n=14) and Staphylococcus aureus (n=14) isolates collected at the University of Iowa Hospitals and Clinics. An additional 9 S. pyogenes isolates were collected from patients being treated for mild respiratory infections and served as a comparison sample in the analysis. Patient data corresponding to the isolates (n=37) were also collected in order to identify risk factors or comorbid conditions possibly correlated with necrotizing fasciitis (NF). The prevalence of methicillin-resistant S. aureus among the study isolates was 35.7% (5/14), and the prevalence of the Panton-Valentine leukocidin (PVL) gene was 57% (8/14). The S. pyogenes NF (wound) isolates (n=14) belonged to 10 different emm types, none of which appeared to be associated with more severe disease when compared to the milder infection (throat) samples (n=9). Comorbid conditions such as diabetes and cardiovascular disease were significantly associated with NF. The results indicate that there may be a high prevalence of the PVL virulence factor in NF infections and that spa type t008 may be responsible for the increasing incidence of S. aureus NF infections in Iowa. Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.
Goudarzi, Mehdi; Fazeli, Maryam; Goudarzi, Hossein; Azad, Mehdi; Seyedjavadi, Sima Sadat
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. This study determined the prevalence of methicillin-resistant S. aureus and different spa types in S. aureus clinical isolates. 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. 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. 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.
Wang, Xiaoguang; Ouyang, Lin; Luo, Lingfei; Liu, Jiqian; Song, Chiping; Li, Cuizhen; Yan, Hongjing; Wang, Ping
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.
Full Text Available To date methicillin-resistant Staphylococcus aureus (MRSA is one of the most common pathogens causing nosocomial infections(1. In Europe the proportion of MRSA is increasing sharply and the distribution varies from country to country. In recent years there has, in various parts of the world, the emergence of infection with strains of S. aureus methicillin-resistant community-acquired (CA-MRSA than those circulating in hospitals(2. These strains contain a gene that confers resistance to methicillin (mec A SSC mec IV which is usually associated with the gene for Leukocidin Panton Valentine (PVL toxin responsible for necrosis of skin and soft tissue (3. In 2006-2008, at the Laboratory of Bacteriology PolyclinicTor Vergata,were isolated a total of 738 strains of S. aureus from biological samples of different nature (oral, vaginal secretions, wound swab, secreted headset, etc ... of patients related to our surgeries.The identification and study of drug sensitivity of strains were performed with the automatic VITEK2 (bioMérieux. Of the 738 strains of S. aureus identified 212 (28.7% were resistant to methicillin (MRSA, with an increasing trend over the years: 46 isolates, respectively, in 2006, 76 in 2007 and 90 in 2008. The highest frequency of MRSA (varying between 85% and 95% was detected in wound swabs from the dispensary and diabetes (diabetic foot.
William J Peppard
Full Text Available William J Peppard1, Anne Daniels1, Lynne Fehrenbacher2, Jamie Winner31Froedtert Hospital Milwaukee, Wisconsin, USA; 2Aurora St Luke’s Medical Center Milwaukee, Wisconsin, USA; 3Clement J Zablocki VA Medical Center, Milwaukee, Wisconsin, USAAbstract: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA infections have increased dramatically over the last two decades. The types of infections can range from complicated skin and skin structure infections (cSSSI to pneumonia and endocarditis. Oral antimicrobial therapy, such as trimethoprim-sulfamethoxazole, clindamycin, long-acting tetracyclines, or linezolid may provide enhanced benefit to those with uncomplicated cutaneous lesions when used in conjunction with incision and drainage in an outpatient setting. However, resistance, susceptibilities, patient-specific circumstances, and adverse effects can impact a healthcare professional’s choice of antibiotics. In patients with complicated infections requiring hospitalization or parenteral treatment, vancomycin remains the drug of choice, even though increased resistance and decreased efficacy have crept into clinical practice. Linezolid, quinupristin/dalfopristin, daptomycin, and tigecycline are alternative intravenous agents for the treatment of CA-MRSA. Investigational agents such as dalbavancin, telavancin, oritivancin, iclaprim, ceftobiprole, ceftaroline, and others may expand our therapeutic armamentarium for the treatment of infections caused by CA-MRSA in the future.Keywords: community-associated methicillin-resistant Staphylococcus aureus, CA-MRSA, complicated skin and skin structure infections, cSSSI, Panton-Valentine leukocidin, PVL, in vitro activity
Kraushaar, Britta; Fetsch, Alexandra
Staphylococcus aureus is an important food-borne pathogen due to the ability of enterotoxigenic strains to produce staphylococcal enterotoxins (SEs) in food. Methicillin-resistant S. aureus (MRSA) is also an important pathogen for humans, causing severe and hard to treat diseases in hospitals and in the community due to its multiresistance against antimicrobials. In particular, strains harbouring genes encoding for the Panton-Valentine leukocidin (PVL) toxin are of concern from a public health perspective as they are usually capable of causing severe skin and soft tissue infections (sSSTIs) and occasionally necrotizing pneumonia which is associated with high mortality. This is the first report on the detection of MRSA with genes encoding for PVL in wild boar meat. Among the 28 MRSA isolated from wild boar meat in the course of a national monitoring programme in Germany, seven harboured PVL-encoding genes. Six of the isolates were identical according to the results of spa-, MLST-, microarray- and PFGE-typing. They could be assigned to the epidemic MRSA clone USA300. Epidemiological investigations revealed that people handling the food were the most likely common source of contamination with these MRSA. These findings call again for suitable hygienic measures at all processing steps of the food production chain. The results of the study underline that monitoring along the food chain is essential to closely characterise the total burden of MRSA for public health. Copyright © 2014. Published by Elsevier B.V.
Full Text Available Understanding the pathology resulting from Staphylococcus aureus and Pseudomonas aeruginosa polymicrobial wound infections is of great importance due to their ubiquitous nature, increasing prevalence, growing resistance to antimicrobial agents, and ability to delay healing. Methicillin-resistant S. aureus USA300 is the leading cause of community-associated bacterial infections resulting in increased morbidity and mortality. We utilized a well-established porcine partial thickness wound healing model to study the synergistic effects of USA300 and P. aeruginosa on wound healing. Wound re-epithelialization was significantly delayed by mixed-species biofilms through suppression of keratinocyte growth factor 1. Pseudomonas showed an inhibitory effect on USA300 growth in vitro while both species co-existed in cutaneous wounds in vivo. Polymicrobial wound infection in the presence of P. aeruginosa resulted in induced expression of USA300 virulence factors Panton-Valentine leukocidin and α-hemolysin. These results provide evidence for the interaction of bacterial species within mixed-species biofilms in vivo and for the first time, the contribution of virulence factors to the severity of polymicrobial wound infections.
Scherr, Tyler D.; Hanke, Mark L.; Huang, Ouwen; James, David B. A.; Horswill, Alexander R.; Bayles, Kenneth W.; Fey, Paul D.; Torres, Victor J.
ABSTRACT The macrophage response to planktonic Staphylococcus aureus involves the induction of proinflammatory microbicidal activity. However, S. aureus biofilms can interfere with these responses in part by polarizing macrophages toward an anti-inflammatory profibrotic phenotype. Here we demonstrate that conditioned medium from mature S. aureus biofilms inhibited macrophage phagocytosis and induced cytotoxicity, suggesting the involvement of a secreted factor(s). Iterative testing found the active factor(s) to be proteinaceous and partially agr-dependent. Quantitative mass spectrometry identified alpha-toxin (Hla) and leukocidin AB (LukAB) as critical molecules secreted by S. aureus biofilms that inhibit murine macrophage phagocytosis and promote cytotoxicity. A role for Hla and LukAB was confirmed by using hla and lukAB mutants, and synergy between the two toxins was demonstrated with a lukAB hla double mutant and verified by complementation. Independent confirmation of the effects of Hla and LukAB on macrophage dysfunction was demonstrated by using an isogenic strain in which Hla was constitutively expressed, an Hla antibody to block toxin activity, and purified LukAB peptide. The importance of Hla and LukAB during S. aureus biofilm formation in vivo was assessed by using a murine orthopedic implant biofilm infection model in which the lukAB hla double mutant displayed significantly lower bacterial burdens and more macrophage infiltrates than each single mutant. Collectively, these findings reveal a critical synergistic role for Hla and LukAB in promoting macrophage dysfunction and facilitating S. aureus biofilm development in vivo. PMID:26307164
Becker, Karsten; Schaumburg, Frieder; Fegeler, Christian; Friedrich, Alexander W; Köck, Robin
This prospective cohort study evaluates colonization dynamics and molecular characteristics of methicillin-susceptible and - resistant Staphylococcus aureus (MSSA/MRSA) in a German general population. Nasal swabs of 1878 non-hospitalized adults were screened for S. aureus. Participants were screened thrice in intervals of 6-8 months. Isolates were characterized by spa and agr typing, mecA and mecC possession, respectively, and PCRs targeting virulence factors. 40.9% of all participants carried S. aureus at least once while 0.7% of the participants carried MRSA (mainly spa t011). MSSA isolates (n=1359) were associated with 331 different spa types; t084 (7.7%), t091 (6.1%) and t012 (71, 5.2%) were predominant. Of 206 participants carrying S. aureus at all three sampling time points, 14.1% carried the same spa type continuously; 5.3% carried different spa types with similar repeat patterns, but 80.6% carried S. aureus with unrelated spa types. MSSA isolates frequently harboured genes encoding enterotoxins (sec: 16.6%, seg: 63.1%, sei: 64.5%) and toxic shock syndrome toxin (tst: 17.5%), but rarely Panton-Valentine leukocidin (lukS-PV/lukF-PV: 0.2%). MSSA colonizing human nares in the community are clonally highly diverse. Among those constantly carrying S. aureus, clonal lineages changed over time. The proportion of persistent S. aureus carriers was lower than reported elsewhere. Copyright © 2016 Elsevier GmbH. All rights reserved.
Leibler, Jessica H; Jordan, Jeanne A; Brownstein, Kirsten; Lander, Lina; Price, Lance B; Perry, Melissa J
Occupational contact with livestock is an established risk factor for exposure to livestock-associated methicillin-resistant Staphylococcus aureus (MRSA), particularly among industrial swine workers. While S. aureus is known to infect cattle, livestock-associated S. aureus carriage among workers in the beef production chain has received limited attention. Beefpacking workers, who slaughter, butcher and process cattle, have intensified exposure to potentially infectious animal materials and may be at risk of livestock-associated S. aureus exposure. We conducted a cross-sectional study of beefpacking workers (n = 137) at an industrial slaughterhouse in the Midwestern United States to evaluate prevalence and characteristics of S. aureus nasal colonization, specifically the absence of the scn gene to identify putative association with livestock, antibiotic susceptibility, presence of Panton-Valentin leukocidin (PVL) genes lukS-PV and lukF-PV, and spa type. Overall prevalence of S. aureus nasal carriage was 27.0%. No workers carried livestock-associated MRSA. Methicillin-sensitive S. aureus isolates (MSSA) recovered from five workers (3.6%) lacked the scn gene and were considered putative livestock-associated S. aureus (pLA-SA). Among pLA-SA isolates, spa types t338, t748, t1476 and t2379 were identified. To our knowledge, these spa types have not previously been identified as associated with livestock. Prevalence of human-adapted MRSA carriage in workers was 3.6%. MRSA isolates were identified as spa types t002, t008 and t024, and four of five MRSA isolates were PVL-positive. To date, this is the first study to indicate that industrial beefpacking workers in the United States may be exposed to livestock-associated S. aureus, notably MSSA, and to spa types not previously identified in livestock and livestock workers. Occupational exposure to livestock-associated S. aureus in the beef production chain requires further epidemiologic investigation.
Sobhanipoor, Mohammad Hossein; Ahmadrajabi, Roya; Karmostaji, Afsaneh; Saffari, Fereshteh
Colonization of methicillin resistant Staphylococccus aureus (MRSA) can occur more commonly in healthy people who live in close together or are in close physical contact with each other. Having knowledge about the molecular characteristics of these strains provides considerable discernment into the epidemiology of this important microorganism. A total of 806 nasal swabs were collected from healthy workers of an automaker company in the southeast of Iran and were analyzed to detect MRSA isolates. Multilocus sequence typing (MLST), spa typing, and detection of staphylococcal cassette chromosome mec (SCCmec) were performed. The presence of genes encoding Panton-Valentine Leukocidin (PVL) and Arginine Catabolic Mobile Element (ACME) were also investigated. Carriage rate of S. aureus was 20%. Among 10 identified MRSA, no acme was found while high prevalence of pvl (60%) was of great concern. Seven different spa types including five new ones were identified. The most frequent sequence type was the novel one; ST 3373 (n = 3), followed by each of ST22, ST88, ST859 (n = 2) and ST1955 (n = 1). MRSA isolates were clustered into two main clonal complexes; CC22 (n = 6) and CC88 (n = 4). Low genetic diversity with the dominance of CC22, SCCmecIV was found. Distribution of previously found hospital-associated MRSA was demonstrated among our isolates. © 2017 APMIS. Published by John Wiley & Sons Ltd.
Santosaningsih, Dewi; Santoso, Sanarto; Setijowati, Nanik; Rasyid, Harun A; Budayanti, Nyoman S; Suata, Ketut; Widhyatmoko, Dicky B; Purwono, Priyo B; Kuntaman, Kuntaman; Damayanti, Damayanti; Prakoeswa, Cita R S; Laurens, Mitchell; van Nierop, Josephine W I; Nanninga, Geraldine L; Oudenes, Neline; de Regt, Michelle; Snijders, Susan V; Verbrugh, Henri A; Severin, Juliëtte A
To define the role of Staphylococcus aureus in community settings among patients with skin and soft tissue infections (SSTI) in Indonesia. Staphylococcus aureus were cultured from anterior nares, throat and wounds of 567 ambulatory patients presenting with SSTI. The mecA gene and genes encoding Panton-Valentine leukocidin (PVL; lukF-PV and lukS-PV) and exfoliative toxin (ET; eta and etb) were determined by PCR. Clonal relatedness among methicillin-resistant S. aureus (MRSA) and PVL-positive S. aureus was analysed using multilocus variable-number tandem-repeat analysis (MLVA) typing, and multilocus sequence typing (MLST) for a subset of isolates. Staphylococcal cassette chromosome mec (SCCmec) was determined for all MRSA isolates. Moreover, determinants for S. aureus SSTI, and PVL/ET-positive vs PVL/ET-negative S. aureus were assessed. Staphylococcus aureus were isolated from SSTI wounds of 257 (45.3%) patients, eight (3.1%) of these were MRSA. Genes encoding PVL and ETs were detected in 21.8% and 17.5% of methicillin-susceptible S. aureus (MSSA), respectively. PVL-positive MRSA was not detected. Nasopharyngeal S. aureus carriage was an independent determinant for S. aureus SSTI (odds ratio [OR] 1.8). Primary skin infection (OR 5.4) and previous antibiotic therapy (OR 3.5) were associated with PVL-positive MSSA. Primary skin infection (OR 2.2) was the only factor associated with ET-positive MSSA. MLVA typing revealed two more prevalent MSSA clusters. One ST1-MRSA-SCCmec type IV isolate and a cluster of ST239-MRSA-SCCmec type III were found. Community-acquired SSTI in Indonesia was frequently caused by PVL-positive MSSA, and the hospital-associated ST239-MRSA may have spread from the hospital into the community. © 2017 John Wiley & Sons Ltd.
Kuehnert, Matthew J; Kruszon-Moran, Deanna; Hill, Holly A; McQuillan, Geraldine; McAllister, Sigrid K; Fosheim, Gregory; McDougal, Linda K; Chaitram, Jasmine; Jensen, Bette; Fridkin, Scott K; Killgore, George; Tenover, Fred C
Staphylococcus aureus is a common cause of disease, particularly in colonized persons. Although methicillin-resistant S. aureus (MRSA) infection has become increasingly reported, population-based S. aureus and MRSA colonization estimates are lacking. Nasal samples for S. aureus culture and sociodemographic data were obtained from 9622 persons > or = 1 year old as part of the National Health and Nutrition Examination Survey, 2001-2002. After screening for oxacillin susceptibility, MRSA and selected methicillin-susceptible S. aureus isolates were tested for antimicrobial susceptibility, pulsed-field gel electrophoresis clonal type, toxin genes (e.g., for Panton-Valentine leukocidin [PVL]), and staphylococcal cassette chromosome mec (SCCmec) type I-IV genes. For 2001-2002, national S. aureus and MRSA colonization prevalence estimates were 32.4% (95% confidence interval [CI], 30.7%-34.1%) and 0.8% (95% CI, 0.4%-1.4%), respectively, and population estimates were 89.4 million persons (95% CI, 84.8-94.1 million persons) and 2.3 million persons (95% CI, 1.2-3.8 million persons), respectively. S. aureus colonization prevalence was highest in participants 6-11 years old. MRSA colonization was associated with age > or = 60 years and being female but not with recent health-care exposure. In unweighted analyses, the SCCmec type IV gene was more frequent in isolates from participants of younger age and of non-Hispanic black race/ethnicity; the PVL gene was present in 9 (2.4%) of 372 of isolates tested. Many persons in the United States are colonized with S. aureus; prevalence rates differ demographically. MRSA colonization prevalence, although low nationally in 2001-2002, may vary with demographic and organism characteristics.
In recent years, methicillin-resistant Staphylococcus aureus (MRSA) have become a truly global challenge. In addition to the long-known healthcare-associated clones, novel strains have also emerged outside of the hospital settings, in the community as well as in livestock. The emergence and spread of virulent clones expressing Panton-Valentine leukocidin (PVL) is an additional cause for concern. In order to provide an overview of pandemic, epidemic and sporadic strains, more than 3,000 clinical and veterinary isolates of MRSA mainly from Germany, the United Kingdom, Ireland, France, Malta, Abu Dhabi, Hong Kong, Australia, Trinidad & Tobago as well as some reference strains from the United States have been genotyped by DNA microarray analysis. This technique allowed the assignment of the MRSA isolates to 34 distinct lineages which can be clearly defined based on non-mobile genes. The results were in accordance with data from multilocus sequence typing. More than 100 different strains were distinguished based on affiliation to these lineages, SCCmec type and the presence or absence of PVL. These strains are described here mainly with regard to clinically relevant antimicrobial resistance- and virulence-associated markers, but also in relation to epidemiology and geographic distribution. The findings of the study show a high level of biodiversity among MRSA, especially among strains harbouring SCCmec IV and V elements. The data also indicate a high rate of genetic recombination in MRSA involving SCC elements, bacteriophages or other mobile genetic elements and large-scale chromosomal replacements.
Monecke, Stefan; Coombs, Geoffrey; Shore, Anna C.; Coleman, David C.; Akpaka, Patrick; Borg, Michael; Chow, Henry; Ip, Margaret; Jatzwauk, Lutz; Jonas, Daniel; Kadlec, Kristina; Kearns, Angela; Laurent, Frederic; O'Brien, Frances G.; Pearson, Julie; Ruppelt, Antje; Schwarz, Stefan; Scicluna, Elizabeth; Slickers, Peter; Tan, Hui-Leen; Weber, Stefan; Ehricht, Ralf
In recent years, methicillin-resistant Staphylococcus aureus (MRSA) have become a truly global challenge. In addition to the long-known healthcare-associated clones, novel strains have also emerged outside of the hospital settings, in the community as well as in livestock. The emergence and spread of virulent clones expressing Panton-Valentine leukocidin (PVL) is an additional cause for concern. In order to provide an overview of pandemic, epidemic and sporadic strains, more than 3,000 clinical and veterinary isolates of MRSA mainly from Germany, the United Kingdom, Ireland, France, Malta, Abu Dhabi, Hong Kong, Australia, Trinidad & Tobago as well as some reference strains from the United States have been genotyped by DNA microarray analysis. This technique allowed the assignment of the MRSA isolates to 34 distinct lineages which can be clearly defined based on non-mobile genes. The results were in accordance with data from multilocus sequence typing. More than 100 different strains were distinguished based on affiliation to these lineages, SCCmec type and the presence or absence of PVL. These strains are described here mainly with regard to clinically relevant antimicrobial resistance- and virulence-associated markers, but also in relation to epidemiology and geographic distribution. The findings of the study show a high level of biodiversity among MRSA, especially among strains harbouring SCCmec IV and V elements. The data also indicate a high rate of genetic recombination in MRSA involving SCC elements, bacteriophages or other mobile genetic elements and large-scale chromosomal replacements. PMID:21494333
Grönlund Andersson, Ulrika; Wallensten, Anders; Hæggman, Sara; Greko, Christina; Hedin, Göran; Hökeberg, Ingegerd; Lindström, Fredrik; Olsson-Liljequist, Barbro; Smedjegård, Jan; Söderblom, Tomas; Windahl, Ulrika; Struwe, Johan
Methicillin-resistant Staphylococcus aureus (MRSA) was found in a dog for the first time in Sweden in 2006. Between October 2006 and May 2007, MRSA was diagnosed in 7 more dogs that had been treated in 3 different small animal hospitals, located 150-200 km apart, in different counties of Sweden. Screening of the animal hospital staff and environment in these small animal hospitals showed 20 of 152 staff to be positive for MRSA, with rates between 2% and 18% in the different hospitals, while all 128 environmental samples were negative. All MRSA isolates from dogs and staff belonged to spa type t032, were Panton-Valentine leukocidin (PVL)-negative, and had indistinguishable pulsed-field gel electrophoresis patterns, except for 2 isolates with closely related patterns. To our knowledge, this is the first report of multiple outbreaks of MRSA in dogs caused by the same strain within a short time frame, and appearing in a country with low prevalence of MRSA in both humans and dogs. This highlights the importance of infection control programs in animal hospitals and in animal health care. Awareness of MRSA as an occupational risk for veterinary personnel is essential.
Borbón-Esquer, Eunice Mireya; Villaseñor-Sierra, Alberto; Martínez-López, Erika; Jáuregui-Lomeli, Juan José; Villaseñor-Martínez, Rosa; Ruiz-Briseño, Mariana Del Rocío
The aim of this study was to determine the prevalence, SCCmec types, presence of the Panton-Valentine leukocidin (PVL) gene, and susceptibility to antibiotics of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from hospitalized children. From August 2009 to September 2011, 291 S. aureus strains were isolated from normally sterile body sites, of which 190 (65%) were MRSA. One hundred and two of the MRSA strains were genetically evaluated. SCCmec genotypes were identified by M-PCR and the PVL gene (pvl) by end-point PCR. Resistance to erythromycin, rifampicin, clindamycin, and trimethoprim-sulfamethoxazole (SXT) was assessed by Kirby-Bauer disk diffusion method in accordance with the Clinical and Laboratory Standards Institute guidelines of 2012. Of the 102 strains evaluated, 97 (95%) were SCCmec type II, 5 (5%) were SCCmec type IVa, and all (100%) were pvl-negative. Resistance to erythromycin, clindamycin, rifampicin, and SXT was 97%, 95%, 0%, and 0%, respectively. The prevalence of hospital-acquired MRSA was high. SCCmec type II was predominant and the pvl gene appeared not to play any role in the virulence of the MRSA strains from hospitalized children.
Lindqvist, Maria; Isaksson, Barbro; Samuelsson, Annika; Nilsson, Lennart E; Hallgren, Anita
In contrast to methicillin-resistant Staphylococcus aureus (MRSA), studies on clonal distribution of methicillin-susceptible S. aureus (MSSA) are scarce. Since 2004, an increasing incidence of concomitant resistance to erythromycin, clindamycin and tobramycin (ECT) among MSSA has been detected in Ostergotland County, Sweden. The objectives of this study were to investigate the genetic relatedness among these isolates with 2 genotyping methods, pulsed-field gel electrophoresis (PFGE), and sequence-based typing of the polymorphic region X of the staphylococcal protein A gene (spa typing), and to determine the incidence of the Panton-Valentine leukocidin (PVL) gene. When genotyping 54 ECT-resistant MSSA isolates from 49 patients (1 isolate per patient per y), 91% were shown to be part of a clonal outbreak with both methods used (spa type t002). The clonal outbreak was concentrated in 8 hospital departments and 2 primary care centres, all located in the city of Linkoping. All isolates were negative for the PVL gene. In conclusion, this study demonstrates an ongoing clonal outbreak of PVL-negative ECT-resistant MSSA. This stresses the need to continuously maintain basic hygiene rules, since nosocomial transmission of pathogens is not limited to known resistant bacteria such as MRSA.
Jenney, Adam; Holt, Deborah; Ritika, Roselyn; Southwell, Paul; Pravin, Shalini; Buadromo, Eka; Carapetis, Jonathan; Tong, Steven; Steer, Andrew
There are few data describing the microbiology and genetic typing of Staphylococcus aureus that cause infections in developing countries. In this study we observed S. aureus infections in Pacific Island nation of Fiji in both the community and hospital setting with an emphasis on clonal complex (CC) genotyping and antimicrobial susceptibility. S. aureus was commonly found in impetigo lesions of school children and was recovered from 57% of impetigo lesions frequently in conjunction with group A streptococcal infection. Methicillin-resistant S. aureus (MRSA) comprised 7% (20/299) of isolates and were all non-multi-resistant and all genotyped as CC1. In contrast, there was a diverse selection of 17 CCs among the 105 genotyped methicillin-susceptible S.aureus (MSSA) strains. Isolates of the rare, phylogenetically divergent and non-pigmented CC75 lineage (also called S. argenteus) were found in Fiji.From hospitalized patients the available 36 MRSA isolates from a 9-month period were represented by five CCs. The most common CCs were CC1 and CC239. CC1 is likely to be a community-acquired strain, reflecting what was found in the school children, whereas the CC239 is the very successful multi-drug resistant MRSA nosocomial lineage. Of 17 MSSA isolates, 59% carried genes for Panton-Valentine leukocidin. The S. aureus bacteraemia incidence rate of 50 per 100,000 population is among the highest reported in the literature and likely reflects the high overall burden of staphylococcal infections in this population. S. aureus is an important cause of disease in Fiji and there is considerable genotypic diversity in community skin infections in Fijian schoolchildren. Community acquired- (CA)- MRSA is present at a relatively low prevalence (6.7%) and was solely to CC1 (CA-MRSA). The globally successful CC239 is also a significant pathogen in Fiji.
Thapaliya, Dipendra; Forshey, Brett M; Kadariya, Jhalka; Quick, Megan K; Farina, Sarah; O' Brien, Ashley; Nair, Rajeshwari; Nworie, Amos; Hanson, Blake; Kates, Ashley; Wardyn, Shylo; Smith, Tara C
Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of infectious disease morbidity and mortality. Previous studies have confirmed the presence of S. aureus, including MRSA, on raw meat products. We investigated the prevalence and molecular epidemiology of S. aureus and MRSA in commercially-distributed antibiotic-free and conventional raw meat products (n = 3290) purchased in 8 Iowa retail stores weekly for a period of one year. Isolates were characterized using spa typing, and PCR was used to detect the presence of the Panton-Valentine leukocidin (PVL) and mecA genes. Quantitation of S. aureus on meat products was carried out one week per month. The prevalence of S. aureus on meat samples was 27.8% (913/3290). Compared to antibiotic-free meat samples, higher prevalence of both MRSA and methicillin-susceptible S. aureus (MSSA) were found in conventional meat samples. Among the S. aureus isolates, 18 were PVL-positive (1.9%) and 41 (4.5%) carried mecA. Phenotypic oxacillin resistance was observed for 17.1% (41/239) of the isolates tested, while 23% (55/239) were multi-drug resistant. A total of 132 spa types were detected from 913 contaminated meat samples. Overall, t002 was the most common spa type identified (137; 15.0%). The number of colony-forming units (CFU) per 10 g meat ranged from 2 to 517 (median: 8 CFU per 10 g of meat; mean: 28) with the highest bacterial load observed on turkey samples. These data reinforce the need to consider meat products as potential vehicles of S. aureus transmission from farm into human households, and the potential need for public health intervention programs pre and post-slaughter in meat processing facilities. Copyright © 2017 Elsevier Ltd. All rights reserved.
Herrera, Fanny C; García-López, María-Luisa; Santos, Jesús A
The aim of this study was the characterization of a collection of 8 methicillin-resistant Staphylococcus aureus (MRSA) isolates, obtained from samples of fresh cheese (Doble Crema) produced from raw cow milk in small dairies in Colombia. All the isolates harbored the mecA and Panton-Valentine leukocidin (PVL) genes, presented with SCCmec type IV, and belonged to multilocus sequence type 8 and spa type 024. Seven isolates presented 3 closely related pulsed-field gel electrophoresis profiles. Three of them carried the staphylococcal enterotoxin B gene. The isolates were resistant to cefoxitin, oxacillin, penicillin, and ampicillin and susceptible to all non-β-lactams antibiotics tested, with minimum inhibitory concentration values for oxacillin of 4 to 8mg/L. The isolates belonged to the community-acquired MRSA group, suggesting a human source of contamination. The risk of human infection by MRSA via contaminated foods is considered low, but contaminated food commodities can contribute to the worldwide dissemination of clones of community-acquired MRSA. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Full Text Available Background: In November 2012, an outbreak of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA skin and soft tissue infections affecting students at a boarding school in Hong Kong (China was detected. Methods: A case was defined as any student or staff notified with MRSA infection from 25 October 2012 to 5 July 2013 with the clinical isolate being of staphylococcal cassette chromosome mec type IV or V and positive for Panton-Valentine leukocidin gene. We conducted field investigations, advised on control measures and enhanced surveillance for skin and soft tissue infections at the school. Decolonization therapies were offered to all cases and contacts, and carrier screening was conducted. Results: There were five cases; two (40% were hospitalized and three (60% required surgical treatments. Initial screening comprised 240 students and 81 staff members. Overall, four cases (80% plus eight other students (3.3% were carriers, with eight of 12 (66.7% from the same dormitory. All staff members screened negative. After intensified control measures, the number of students screened positive for CA-MRSA decreased from nine to one with no more cases identified in the school. Conclusion: Identification of carriers, decolonization therapy, monitoring of cases and contacts and strengthening of environmental and personal hygiene were control measures that helped contain this CA-MRSA outbreak in a boarding school in Hong Kong (China.
Ahmed, Mohamed O; Baptiste, Keith E; Daw, Mohamed A; Elramalli, Asma K; Abouzeed, Yousef M; Petersen, Andreas
The purpose of the study was to investigate the molecular characteristics of meticillin-resistant Staphylococcus aureus (MRSA) isolated from clinical sources in Tripoli, Libya. A total of 95 MRSA strains collected at the Tripoli medical Centre were investigated by spa typing and identification of the Panton-Valentine Leukocidin (pvl) genes. A total of 26 spa types were characterized and distributed among nine clonal complexes; CC5 (n=32), CC80 (n=18), CC8 (n=17) and CC22 (n=12) were the most prevalent clonal complexes. In total, 34% of the isolates were positive for PVL. This study demonstrated the presence of CA-MRSA and pvl positive strains in hospital settings and underlines the importance of using molecular typing to investigate the epidemiology of MRSA. Preventative measures and surveillance systems are needed to control and minimize the spread of MRSA in the Libyan health care system. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.
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.
Nurjadi, D; Friedrich-Jänicke, B; Schäfer, J; Van Genderen, P J J; Goorhuis, A; Perignon, A; Neumayr, A; Mueller, A; Kantele, A; Schunk, M; Gascon, J; Stich, A; Hatz, C; Caumes, E; Grobusch, M P; Fleck, R; Mockenhaupt, F P; Zanger, P
Staphylococcus aureus is emerging globally. Treatment of infections is complicated by increasing antibiotic resistance. We collected clinical data and swabs of returnees with skin and soft tissue infections (SSTI) at 13 travel-clinics in Europe (www.staphtrav.eu). Sixty-two percent (196/318) SSTI patients had S. aureus-positive lesions, of which almost two-thirds (122/196) were Panton-Valentine leukocidin (PVL) positive. PVL was associated with disease severity, including hospitalization for SSTI (OR 5.2, 95% CI 1.5-18.2). In returnees with SSTI, longer travel and more intense population contact were risk factors for nasal colonization with PVL-positive S. aureus. Imported S. aureus frequently proved resistant to trimethoprim-sulfamethoxazole (21%), erythromycin (21%), tetracycline (20%), ciprofloxacin (13%), methicillin (12%) and clindamycin (8%). Place of exposure was significantly (p Europe and were predominantly (71%) acquired in Latin America. Multi-resistance to non-β-lactams were present in 24% of imports and associated with travel to South Asia (ORcrude 5.3, 95% CI 2.4-11.8), even after adjusting for confounding by genotype (ORadjusted 3.8, 95% 1.5-9.5). Choosing randomly from compounds recommended for the empiric treatment of severe S. aureus SSTI, 15% of cases would have received ineffective antimicrobial therapy. These findings call for the development of regionally stratified guidance on the antibiotic management of severe imported S. aureus disease and put the infected and colonized traveller at the centre of interventions against the global spread of multi-resistant S. aureus. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
Salazar-Ospina, Lorena; Jiménez, Judy Natalia
Staphylococcus aureus is responsible for a large number of infections in pediatric population; however, information about the behavior of such infections in this population is limited. The aim of the study was to describe the clinical, epidemiological, and molecular characteristics of infections caused by methicillin-susceptible and resistant S. aureus (MSSA-MRSA) in a pediatric population. A cross-sectional descriptive study in patients from birth to 14 years of age from three high-complexity institutions was conducted (2008-2010). All patients infected with methicillin-resistant S. aureus and a representative sample of patients infected with methicillin-susceptible S. aureus were included. Clinical and epidemiological information was obtained from medical records and molecular characterization included spa typing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). In addition, staphylococcal cassette chromosome mec (SCCmec) and virulence factor genes were detected. A total of 182 patients, 65 with methicillin-susceptible S. aureus infections and 117 with methicillin-resistant S. aureus infections, were included in the study; 41.4% of the patients being under 1 year. The most frequent infections were of the skin and soft tissues. Backgrounds such as having stayed in day care centers and previous use of antibiotics were more common in patients with methicillin-resistant S. aureus infections (p≤0.05). Sixteen clonal complexes were identified and methicillin-susceptible S. aureus strains were more diverse. The most common cassette was staphylococcal cassette chromosomemec IVc (70.8%), which was linked to Panton-Valentine leukocidin (pvl). In contrast with other locations, a prevalence of infections in children under 1 year of age in the city could be observed; this emphasizes the importance of epidemiological knowledge at the local level. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights
Rojas, Irene; Barquero-Calvo, Elías; van Balen, Joany C; Rojas, Norman; Muñoz-Vargas, Lohendy; Hoet, Armando E
Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen associated with severe infections in companion animals present in the community, and it is diagnosed in animals admitted to veterinary hospitals. However, reports that describe the circulation of MRSA in animal populations and veterinary settings in Latin America are scarce. Therefore, the objective of this study was to determine the prevalence and investigate the molecular epidemiology of MRSA in the environment of the largest veterinary teaching hospital in Costa Rica. Preselected contact surfaces were sampled twice within a 6-week period. Antimicrobial resistance, SCCmec type, Panton-Valentine leukocidin screening, USA type, and clonality were assessed in all recovered isolates. Overall, MRSA was isolated from 26.5% (27/102) of the surfaces sampled, with doors, desks, and examination tables most frequently contaminated. Molecular analysis demonstrated a variety of surfaces from different sections of the hospital contaminated by three highly related clones/pulsotypes. All, but one of the isolates were characterized as multidrug-resistant SCCmec type IV-USA700, a strain sporadically described in other countries and often classified as community acquired. The detection and frequency of this unique strain in this veterinary setting suggest Costa Rica has a distinctive MRSA ecology when compared with other countries/regions. The high level of environmental contamination highlights the necessity to establish and enforce standard cleaning and disinfection protocols to minimize further spread of this pathogen and reduce the risk of nosocomial and/or occupational transmission of MRSA.
Li, Vincent; Chui, Linda; Louie, Lisa; Simor, Andrew; Golding, George R.; Louie, Marie
Pulsed-field gel electrophoresis (PFGE) is a valuable molecular typing assay used for methicillin-resistant Staphylococcus aureus (MRSA) surveillance and genotyping. However, there are several limitations associated with PFGE. In Alberta, Canada, the significant increase in the number of MRSA isolates submitted to the Provincial Laboratory for Public Health (ProvLab) for PFGE typing led to the need for an alternative genotyping method. In this study, we describe the transition from PFGE to Staphylococcus protein A (spa), Staphylococcal cassette chromosome (SCCmec), and Panton-Valentine leukocidin (PVL) typing. A total of 1915 clinical MRSA isolates collected from 2005 to 2009 were used to develop and validate an algorithm for assigning PFGE epidemic types using spa, SCCmec, and PVL typing and the resulting data was used to populate a new Alberta MRSA typing database. An additional 12620 clinical MRSA isolates collected from 2010 to 2012 as part of ongoing routine molecular testing at ProvLab were characterized using the new typing algorithm and the Alberta MRSA typing database. Switching to spa, SCCmec, and PVL from PFGE typing substantially reduced hands-on and turn-around times while maintaining historical PFGE epidemic type designations. This led to an approximate $77,000 reduction in costs from 2010 to 2012. PFGE typing is still required for a small subset of MRSA isolates that have spa types that are rare, novel, or associated with more than one PFGE epidemic type. PMID:24244440
Rojas, Irene; Barquero-Calvo, Elías; van Balen, Joany C.; Rojas, Norman; Muñoz-Vargas, Lohendy
Abstract Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen associated with severe infections in companion animals present in the community, and it is diagnosed in animals admitted to veterinary hospitals. However, reports that describe the circulation of MRSA in animal populations and veterinary settings in Latin America are scarce. Therefore, the objective of this study was to determine the prevalence and investigate the molecular epidemiology of MRSA in the environment of the largest veterinary teaching hospital in Costa Rica. Preselected contact surfaces were sampled twice within a 6-week period. Antimicrobial resistance, SCCmec type, Panton-Valentine leukocidin screening, USA type, and clonality were assessed in all recovered isolates. Overall, MRSA was isolated from 26.5% (27/102) of the surfaces sampled, with doors, desks, and examination tables most frequently contaminated. Molecular analysis demonstrated a variety of surfaces from different sections of the hospital contaminated by three highly related clones/pulsotypes. All, but one of the isolates were characterized as multidrug-resistant SCCmec type IV-USA700, a strain sporadically described in other countries and often classified as community acquired. The detection and frequency of this unique strain in this veterinary setting suggest Costa Rica has a distinctive MRSA ecology when compared with other countries/regions. The high level of environmental contamination highlights the necessity to establish and enforce standard cleaning and disinfection protocols to minimize further spread of this pathogen and reduce the risk of nosocomial and/or occupational transmission of MRSA. PMID:28816638
Full Text Available Abstract Background Methicillin resistant Staphylococcus aureus (MRSA has been considered for many years a typical nosocomial pathogen. Recently MRSA has emerged as a frequent cause of infections in the community. More commonly, community-acquired (CA-MRSA is a cause of infections of the skin and soft-tissues, but life-threatening infections such as necrotizing pneumonia and sepsis can occasionally occur. Case presentation This report describes an uncommon presentation of invasive CA-MRSA infection in an adolescent without known risk factors. The presentation was typical for bacterial meningitis, but the clinical findings also revealed necrotizing pneumonia. Following the development of deep venous thrombosis, the presence of an inherited trombophilic defect (factor V Leiden was detected. The patient was successfully treated with an antibiotic combination including linezolid and with anticoagulant therapy. CA-MRSA was isolated from both cerebrospinal fluid and blood. The isolates were resistant to oxacillin and other beta-lactam antibiotics and susceptible to the other antibiotics tested including erythromycin. Molecular typing revealed that the strains contained the Panton-Valentine leukocidin genes and type IV SCCmec, and were ST8, spa type t008, and agr type 1. This genetic background is identical to that of the USA300 clone. Conclusion This report highlights that meningitis can be a new serious presentation of CA-MRSA infection. CA-MRSA strains with the genetic background of the USA300 clone are circulating in Italy and are able to cause severe infections.
Valentini, Piero; Parisi, Gabriella; Monaco, Monica; Crea, Francesca; Spanu, Teresa; Ranno, Orazio; Tronci, Mirella; Pantosti, Annalisa
Methicillin resistant Staphylococcus aureus (MRSA) has been considered for many years a typical nosocomial pathogen. Recently MRSA has emerged as a frequent cause of infections in the community. More commonly, community-acquired (CA)-MRSA is a cause of infections of the skin and soft-tissues, but life-threatening infections such as necrotizing pneumonia and sepsis can occasionally occur. This report describes an uncommon presentation of invasive CA-MRSA infection in an adolescent without known risk factors. The presentation was typical for bacterial meningitis, but the clinical findings also revealed necrotizing pneumonia. Following the development of deep venous thrombosis, the presence of an inherited thrombophilic defect (factor V Leiden) was detected. The patient was successfully treated with an antibiotic combination including linezolid and with anticoagulant therapy. CA-MRSA was isolated from both cerebrospinal fluid and blood. The isolates were resistant to oxacillin and other beta-lactam antibiotics and susceptible to the other antibiotics tested including erythromycin. Molecular typing revealed that the strains contained the Panton-Valentine leukocidin genes and type IV SCCmec, and were ST8, spa type t008, and agr type 1. This genetic background is identical to that of the USA300 clone. This report highlights that meningitis can be a new serious presentation of CA-MRSA infection. CA-MRSA strains with the genetic background of the USA300 clone are circulating in Italy and are able to cause severe infections.
Foster, Catherine E; Yarotsky, Elizabeth; Mason, Edward O; Kaplan, Sheldon L; Hulten, Kristina G
Periorbital and orbital cellulitis cause significant pediatric morbidity. Here, we define the clinical features of and characterize isolates from children with periorbital or orbital cellulitis caused by Staphylococcus aureus at Texas Children's Hospital in Houston. Patients were identified from a prospective S aureus study database from January 2002 to July 2015. Demographic and clinical data were collected retrospectively. Isolates were genotyped by pulsed-field gel electrophoresis, and Panton-Valentine leukocidin (lukSF-PV [pvl]) genes were detected by quantitative polymerase chain reaction. Data were analyzed with the Fisher exact or Wilcoxon rank-sum test. Eighty-five patients with periorbital (n = 58) or orbital (n = 27) cellulitis were identified. We found 57 (67%) methicillin-resistant S aureus (MRSA) isolates, 72 (85%) pvl-positive (pvl+) isolates, and 66 (78%) USA300 isolates. No differences in clinical characteristics were found when we compared MRSA to methicillin-susceptible (MSSA) infections or USA300 to non-USA300 infections. Patients with orbital cellulitis were hospitalized a median of 12 days (range, 2-28 days) and received antibiotics for 21 days (range, 10-32 days). Twelve (44%) patients with orbital cellulitis received steroids. Steroid treatment did not affect the length of hospitalization or duration of antibiotic treatment. Six (7%) patients with orbital cellulitis were bacteremic. Patients with periorbital cellulitis were hospitalized for a median of 3 days (range, 0-17 days) and received antibiotics for 11 days (range, 7-32 days). According to computed tomography (CT), 19 (70%) patients with orbital cellulitis and 11 (41%) with periorbital cellulitis had sinusitis. The majority of periorbital and orbital S aureus infections at Texas Children's Hospital were caused by MRSA, and no change was observed over time. Empirical antibiotic treatment should include coverage for MRSA. PVL might be an important virulence factor in these presentations
Dan Dan Sun
Full Text Available In order to obtain adequate information for the treatment of methicillin resistant Staphylococcus aureus (MRSA infections, it is crucial to identify trends in epidemiological and antimicrobial resistance patterns of local S. aureus strains. Community and hospital acquired S. aureus isolates (n = 202 were characterized using staphylococcal cassette chromosome mec (SCCmec typing, pulse field gel electrophoresis (PFGE analysis, spa typing and minimal inhibitory concentration (MIC determination. The prevalence of the Panton-Valentine leukocidine (pvl and several antibiotic resistance genes among the isolates were also detected by PCR. All of the S. aureus isolates were susceptible to vancomycin, daptomycin and linezolid. Three hospital isolates were resistant to teicoplanin while 14 showed intermediate resistance to teicoplanin. The resistance patterns of community-acquired MRSA (CA-MRSA isolates to other antimicrobials were similar to those of hospital-acquired MRSA (HA-MRSA isolates except for clindamycin and gentamicin. There was excellent correlation between phenotypes and genotypes in the determination of S. aureus resistance to erythromycin, gentamicin, and tetracycline. The SCCmec type II and SCCmec type IV were the predominant types detected in hospital and community isolates, respectively. The most frequently encountered spa types were t002 and t030 both in HA-and CA-MRSA isolates. Pulsotype A was the most predominant pulsotype identified among the isolates tested, followed by pulsotype B. Seventy-two hospital isolates (19 HA-MRSA and 53 HA-MSSA and 10 CA-MRSA were positive for the pvl gene. This study shows that the combination of susceptibility testing and various molecular methods has provided useful information on the antibiotic resistance and molecular diversity of S. aureus in a specific region of China. The high proportion of pvl positive MSSA and MRSA isolates observed in this study indicates that adequate measures are needed to
Cremonesi, P; Zottola, T; Locatelli, C; Pollera, C; Castiglioni, B; Scaccabarozzi, L; Moroni, P
Staphylococcus aureus is an important human and animal pathogen, and is regarded as an important cause of intramammary infection (IMI) in ruminants. Staphylococcus aureus genetic variability and virulence factors have been well studied in veterinary medicine, especially in cows as support for control and management of IMI. The aim of the present study was to genotype 71 Staph. aureus isolates from the bulk tank and foremilk of water buffaloes (n=40) and from udder tissue (n=7) and foremilk (n=24) from small ruminants. The method used was previously applied to bovine Staph. aureus and is based on the amplification of the 16S-23S rRNA intergenic spacer region. The technique applied was able to identify different Staph. aureus genotypes isolated from dairy species other than the bovine species, and cluster the genotypes according to species and herds. Virulence gene distribution was consistent with genotype differentiation. The isolates were also characterized through determination of the presence of 19 virulence-associated genes by specific PCR. Enterotoxins A, C, D, G, I, J, and L were associated with Staph. aureus isolates from buffaloes, whereas enterotoxins C and L were linked to small ruminants. Genes coding for methicillin resistance, Panton-Valentine leukocidin, exfoliative toxins A and B, and enterotoxins B, E, and H were undetected. These findings indicate that RNA template-specific PCR is a valid technique for typing Staph. aureus from buffaloes and small ruminants and is a useful tool for understanding udder infection epidemiology. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Diep, Binh An; Le, Vien T M; Visram, Zehra C; Rouha, Harald; Stulik, Lukas; Dip, Etyene Castro; Nagy, Gábor; Nagy, Eszter
Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), especially the USA300 pulsotype, is a frequent cause of skin and soft tissue infections and severe pneumonia. Despite appropriate antibiotic treatment, complications are common and pneumonia is associated with high mortality. S. aureus strains express multiple cytotoxins, including alpha-hemolysin (Hla) and up to five bicomponent leukocidins that specifically target phagocytic cells for lysis. CA-MRSA USA300 strains carry the genes for all six cytotoxins. Species specificity of the leukocidins greatly contributes to the ambiguity regarding their role in S. aureus pathogenesis. We performed a comparative analysis of the leukocidin susceptibility of human, rabbit, and mouse polymorphonuclear leukocytes (PMNs) to assess the translational value of mouse and rabbit S. aureus models. We found that mouse PMNs were largely resistant to LukSF-PV, HlgAB, and HlgCB and susceptible only to LukED, whereas rabbit and human PMNs were highly sensitive to all these cytotoxins. In the rabbit pneumonia model with a USA300 CA-MRSA strain, passive immunization with a previously identified human monoclonal antibody (MAb), Hla-F#5, which cross-neutralizes Hla, LukSF-PV, HlgAB, HlgCB, and LukED, provided full protection, whereas an Hla-specific MAb was only partially protective. In the mouse USA300 CA-MRSA pneumonia model, both types of antibodies demonstrated full protection, suggesting that Hla, but not leukocidin(s), is the principal virulence determinant in mice. As the rabbit recapitulates the high susceptibility to leukocidins characteristic of humans, this species represents a valuable model for assessing novel, cytotoxin-targeting anti-S. aureus therapeutic approaches. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Yeap, Alicia D; Woods, Kate; Dance, David A B; Pichon, Bruno; Rattanavong, Sayaphet; Davong, Viengmon; Phetsouvanh, Rattanaphone; Newton, Paul N; Shetty, Nandini; Kearns, Angela M
This is the first report of the molecular epidemiology of Staphylococcus aureus from skin and soft tissue infections (SSTI) in Laos. We selected a random sample of 96 S. aureus SSTI isolates received by the Microbiology Laboratory, Mahosot Hospital, Vientiane, between July 2012 and June 2014, including representation from seven referral hospitals. Isolates underwent susceptibility testing by Clinical and Laboratory Standards Institute methods, spa typing and DNA microarray analysis, with whole genome sequencing for rare lineages. Median patient age was 19.5 years (interquartile range 2-48.5 years); 52% (50) were female. Forty-three spa types, representing 17 lineages, were identified. Fifty-eight percent (56) of all isolates encoded Panton-Valentine leukocidin (PVL), representing six lineages: half of these patients had abscesses and three had positive blood cultures. The dominant lineage was CC121 (39; 41%); all but one isolate encoded PVL and 49% (19) were from children under five. Staphyococcus argenteus was identified in six (6%) patients; mostly adults > 50 years and with diabetes. Six isolates (6%) belonged to rare lineage ST2885; two possibly indicate cross-infection in a neonatal unit. One isolate from a previously undescribed lineage, ST1541, was identified. Antibiotic resistance was uncommon except for penicillin (93; 97%) and tetracycline (48; 50%). Seven (7%) isolates were methicillin-resistant S. aureus (MRSA), belonging to ST239-MRSA-III, CC59-MRSA-V(T) Taiwan Clone, ST2250-MRSA-IV, ST2885-MRSA-V and CC398-MRSA-V. Globally widespread CC5 and CC30 were absent. There are parallels in S. aureus molecular epidemiology between Laos and neighboring countries and these data highlight the prominence of PVL and suggest infiltration of MRSA clones of epidemic potential from surrounding countries.
Stine Oscar C
Full Text Available Abstract Background HIV patients are at increased risk of development of infections and infection-associated poor health outcomes. We aimed to 1 assess the prevalence of USA300 community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA among HIV-infected patients with S. aureus bloodstream infections and. 2 determine risk factors for infective endocarditis and in-hospital mortality among patients in this population. Methods All adult HIV-infected patients with documented S. aureus bacteremia admitted to the University of Maryland Medical Center between January 1, 2003 and December 31, 2005 were included. CA-MRSA was defined as a USA300 MRSA isolate with the MBQBLO spa-type motif and positive for both the arginine catabolic mobile element and Panton-Valentin Leukocidin. Risk factors for S. aureus-associated infective endocarditis and mortality were determined using logistic regression to calculate odds ratios (OR and 95% confidence intervals (CI. Potential risk factors included demographic variables, comorbid illnesses, and intravenous drug use. Results Among 131 episodes of S. aureus bacteremia, 85 (66% were MRSA of which 47 (54% were CA-MRSA. Sixty-three patients (48% developed endocarditis and 10 patients (8% died in the hospital on the index admission Patients with CA-MRSA were significantly more likely to develop endocarditis (OR = 2.73, 95% CI = 1.30, 5.71. No other variables including comorbid conditions, current receipt of antiretroviral therapy, pre-culture severity of illness, or CD4 count were significantly associated with endocarditis and none were associated with in-hospital mortality. Conclusions CA-MRSA was significantly associated with an increased incidence of endocarditis in this cohort of HIV patients with MRSA bacteremia. In populations such as these, in which the prevalence of intravenous drug use and probability of endocarditis are both high, efforts must be made for early detection, which may improve
Full Text Available Adult community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA and methicillin-susceptible S. aureus (CA-MSSA skin and soft tissue infection (SSTI in China is not well described. A prospective cohort of adults with SSTI was established between January 2009 and August 2010 at 4 hospitals in Beijing. Susceptibility testing and molecular typing, including multilocus sequence typing, spa, agr typing, and toxin detection were assessed for all S. aureus isolates. Overall, 501 SSTI patients were enrolled. Cutaneous abscess (40.7% was the most common infection, followed by impetigo (6.8% and cellulitis (4.8%. S. aureus accounted for 32.7% (164/501 of SSTIs. Five isolates (5/164, 3.0% were CA-MRSA. The most dominant ST in CA-MSSA was ST398 (17.6%. The prevalence of Panton-Valentine Leukocidin (pvl gene was 41.5% (66/159 in MSSA. Female, younger patients and infections requiring incision or drainage were more commonly associated with pvl-positive S. aureus (P<0.03; sec gene was more often identified in CC5 (P<0.03; seh gene was more prevalent in CC1 (P = 0.001. Importantly, ST59 isolates showed more resistance to erythromycin, clindamycin and tetracycline, and needed more surgical intervention. In conclusion, CA-MRSA infections were rare among adult SSTI patients in Beijing. Six major MSSA clones were identified and associated with unique antimicrobial susceptibility, toxin profiles, and agr types. A high prevalence of livestock ST398 clone (17.1% of all S. aureus infections was found with no apparent association to animal contact.
Seier-Petersen, Maria Amalie; Nielsen, Lene Nørby; Ingmer, Hanne; Aarestrup, Frank Møller; Agersø, Yvonne
Methicillin-resistant Staphylococcus aureus (MRSA), in particular clonal complex (CC) 398, is increasingly found in livestock. Recently, MRSA CC30 was identified in Danish pigs. We determined the susceptibility of porcine S. aureus isolates of CC398 and CC30 to disinfectants used in pig farming (benzalkonium chloride, hydrogen peroxide, formaldehyde, sodium hypochlorite, and caustic soda). Furthermore, efflux pump activity, antimicrobial resistance profiles, hemolysis properties, and the presence of toxic shock syndrome toxin-1 (TSST-1) and Panton-Valentine Leukocidin (PVL)-encoding virulence factors were investigated. Susceptibilities to biocides and antimicrobial agents of 79 porcine S. aureus isolates were determined by the microdilution method. Isolates comprised 21 methicillin-sensitive S. aureus (MSSA) and 40 MRSA isolates belonging to CC398 and 13 MSSA and 5 MRSA isolates belonging to CC30. The presence of quaternary ammonium compound (QAC) resistance efflux pumps was analyzed using an ethidium bromide accumulation assay. The presence of qac resistance genes in active efflux pump positive isolates was determined by whole-genome sequencing data. All isolates were screened for lukPV and tst genes with PCR, and hemolytic activities were determined using an agar plate assay. S. aureus isolates did not show reduced susceptibility to the biocides tested. However, the QAC resistance gene, qacG, was detected in three MRSA CC30 isolates and the qacC in one MRSA CC30 isolate. CC30 isolates were generally more susceptible to non-beta-lactam antibiotics than CC398. Isolates generally had low hemolytic activity and none encoded PVL or TSST-1. The presence of qac genes in European porcine S. aureus isolates and in livestock-associated MRSA CC30 is for the first time described in this study. This finding is concerning as it ultimately may compromise disinfection with QACs and thereby contribute to the selection and spread of MRSA CC30.
. The minimum inhibitory concentration of different antimicrobial agents against 118 S. aureus consecutive and prospective isolates was studied by the CLSI agar dilution method. In ORSA isolates without accompanying resistance, the mec- A gene, the Panton-Valentine leukocidin gene (PVL, and the γ-hemolysin gene were determined by PCR, and the SCC cassette mec gene by multiplex PCR. Out of the 118 isolates, 44 were HA-ORSA, 16 were CA-ORSA, and 58 corresponded to OSSA. The HA-ORSA isolates presented simultaneous resistance to erythromycin, clindamycin, gentamicin, ciprofloxacin, levofloxacin, and moxifloxacin whereas all of them were susceptible to tigecycline (TIG, vancomycin, teicoplanin and linezolid (LZD. The CA-ORSA isolates were only resistant to OXA and presented susceptibility to all the antimicrobial agents assayed. In all of them, the mec-A gene, the PVL gene, the γ-hemolysin gene and the SCC cassette mec type IV gene were detected. With the OSSA and CA-ORSA isolates, all the non- β- lactam antimicrobial agents assayed exhibited excellent in vitro activity. However, in the HA-ORSA isolates, only the old antimicrobial agents such as glycopeptides, doxyciclin, rifampin, and trimethoprim-sulfamethoxazole and the new antimicrobial agents LZD and TIG, presented good in vitro activity. The ORSA phenotype without accompanying resistance was highly predictive of CA-ORSA as confirmed by a positive SCC cassette mec type IV.
Immergluck, Lilly Cheng; Jain, Shabnam; Ray, Susan M.; Mayberry, Robert; Satola, Sarah; Parker, Trisha Chan; Yuan, Keming; Mohammed, Anaam; Jerris, Robert C.
Introduction The purpose of this study was to examine community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) carriage and infections and determine risk factors associated specifically with MRSA USA300. Methods We conducted a case control study in a pediatric emergency department. Nasal and axillary swabs were collected, and participants were interviewed for risk factors. The primary outcome was the proportion of S. aureus carriers among those presenting with and without a skin and soft tissue infection (SSTI). We further categorized S. aureus carriers into MRSA USA300 carriers or non-MRSA USA300 carriers. Results We found the MRSA USA300 carriage rate was higher in children less than two years of age, those with an SSTI, children with recent antibiotic use, and those with a family history of SSTI. MRSA USA300 carriers were also more likely to have lower income compared to non-MRSA USA300 carriers and no S. aureus carriers. Rates of Panton-Valentine leukocidin (PVL) genes were higher in MRSA carriage isolates with an SSTI, compared to MRSA carriage isolates of patients without an SSTI. There was an association between MRSA USA300 carriage and presence of PVL in those diagnosed with an abscess. Conclusion Children younger than two years were at highest risk for MRSA USA300 carriage. Lower income, recent antibiotic use, and previous or family history of SSTI were risk factors for MRSA USA300 carriage. There is a high association between MRSA USA300 nasal/axillary carriage and presence of PVL in those with abscesses. PMID:28210352
Ge, Beilei; Mukherjee, Sampa; Hsu, Chih-Hao; Davis, Johnnie A; Tran, Thu Thuy T; Yang, Qianru; Abbott, Jason W; Ayers, Sherry L; Young, Shenia R; Crarey, Emily T; Womack, Niketta A; Zhao, Shaohua; McDermott, Patrick F
Methicillin-resistant Staphylococcus aureus (MRSA) has been detected in retail meats, although large-scale studies are scarce. We conducted a one-year survey in 2010-2011 within the framework of the National Antimicrobial Resistance Monitoring System. Among 3520 retail meats collected from eight U.S. states, 982 (27.9%) contained S. aureus and 66 (1.9%) were positive for MRSA. Approximately 10.4% (107/1032) of S. aureus isolates, including 37.2% (29/78) of MRSA, were multidrug-resistant (MDRSA). Turkey had the highest MRSA prevalence (3.5%), followed by pork (1.9%), beef (1.7%), and chicken (0.3%). Whole-genome sequencing was performed for all 66 non-redundant MRSA. Among five multilocus sequence types identified, ST8 (72.7%) and ST5 (22.7%) were most common and livestock-associated MRSA ST398 was assigned to one pork isolate. Eleven spa types were represented, predominately t008 (43.9%) and t2031 (22.7%). All four types of meats harbored t008, whereas t2031 was recovered from turkey only. The majority of MRSA (84.8%) possessed SCCmec IV and 62.1% harbored Panton-Valentine leukocidin. Pulsed-field gel electrophoresis showed that all ST8 MRSA belonged to the predominant human epidemic clone USA300, and others included USA100 and USA200. We conclude that a diverse MRSA population was present in U.S. retail meats, albeit at low prevalence. Published by Elsevier Ltd.
Development of a new pentaplex real-time PCR assay for the identification of poly-microbial specimens containing Staphylococcus aureus and other staphylococci, with simultaneous detection of staphylococcal virulence and methicillin resistance markers.
Okolie, Charles E; Wooldridge, Karl G; Turner, David P; Cockayne, Alan; James, Richard
Staphylococcus aureus strains harbouring genes encoding virulence and antibiotic resistance are of public health importance. In clinical samples, pathogenic S. aureus is often mixed with putatively less pathogenic coagulase-negative staphylococci (CoNS), both of which can harbour mecA, the gene encoding staphylococcal methicillin-resistance. There have been previous attempts at distinguishing MRSA from MRCoNS, most of which were based on the detection of one of the pathognomonic markers of S. aureus, such as coa, nuc or spa. That approach might suffice for discrete colonies and mono-microbial samples; it is inadequate for identification of clinical specimens containing mixtures of S. aureus and CoNS. In the present study, a real-time pentaplex PCR assay has been developed which simultaneously detects markers for bacteria (16S rRNA), coagulase-negative staphylococcus (cns), S. aureus (spa), Panton-Valentine leukocidin (pvl) and methicillin resistance (mecA). Staphylococcal and non-staphylococcal bacterial strains (n = 283) were used to validate the new assay. The applicability of this test to clinical samples was evaluated using spiked blood cultures (n = 43) containing S. aureus and CoNS in mono-microbial and poly-microbial models, which showed that the 5 markers were all detected as expected. Cycling completes within 1 h, delivering 100% specificity, NPV and PPV with a detection limit of 1.0 × 10(1) to 3.0 × 10(1) colony forming units (CFU)/ml, suggesting direct applicability in routine diagnostic microbiology. This is the most multiplexed real-time PCR-based PVL-MRSA assay and the first detection of a unique marker for CoNS without recourse to the conventional elimination approach. There was no evidence that this new assay produced invalid/indeterminate test results. Copyright © 2015 Elsevier Ltd. All rights reserved.
Stinear, Timothy P.; Holt, Kathryn E.; Chua, Kyra; Stepnell, Justin; Tuck, Kellie L.; Coombs, Geoffrey; Harrison, Paul Francis; Seemann, Torsten; Howden, Benjamin P.
Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged as a major public health problem around the world. In Australia, ST93-IV[2B] is the dominant CA-MRSA clone and displays significantly greater virulence than other S. aureus. Here, we have examined the evolution of ST93 via genomic analysis of 12 MSSA and 44 MRSA ST93 isolates, collected from around Australia over a 17-year period. Comparative analysis revealed a core genome of 2.6 Mb, sharing greater than 99.7% nucleotide identity. The accessory genome was 0.45 Mb and comprised additional mobile DNA elements, harboring resistance to erythromycin, trimethoprim, and tetracycline. Phylogenetic inference revealed a molecular clock and suggested that a single clone of methicillin susceptible, Panton-Valentine leukocidin (PVL) positive, ST93 S. aureus likely spread from North Western Australia in the early 1970s, acquiring methicillin resistance at least twice in the mid 1990s. We also explored associations between genotype and important MRSA phenotypes including oxacillin MIC and production of exotoxins (α-hemolysin [Hla], δ-hemolysin [Hld], PSMα3, and PVL). High-level expression of Hla is a signature feature of ST93 and reduced expression in eight isolates was readily explained by mutations in the agr locus. However, subtle but significant decreases in Hld were also noted over time that coincided with decreasing oxacillin resistance and were independent of agr mutations. The evolution of ST93 S. aureus is thus associated with a reduction in both exotoxin expression and oxacillin MIC, suggesting MRSA ST93 isolates are under pressure for adaptive change. PMID:24482534
Cavalcante, F.S. [Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Abad, E.D. [Instituto de Puericultura e Pediatria Martagão Gesteira, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Lyra, Y.C. [Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Saintive, S.B.; Ribeiro, M. [Instituto de Puericultura e Pediatria Martagão Gesteira, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Ferreira, D.C. [Centre for Ecological and Evolutionary Studies (Microbial Ecology), Faculty of Mathematics and Natural Science, University of Groningen, Groningen (Netherlands); Programa de Pós Graduação em Odontologia, Universidade Estácio de Sá, Rio de Janeiro, RJ (Brazil); Santos, K.R.N. dos [Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil)
Staphylococcus aureus is highly prevalent among patients with atopic dermatitis (AD), and this pathogen may trigger and aggravate AD lesions. The aim of this study was to determine the prevalence of S. aureus in the nares of pediatric subjects and verify the phenotypic and molecular characteristics of the isolates in pediatric patients with AD. Isolates were tested for antimicrobial susceptibility, SCCmectyping, and Panton-Valentine Leukocidin (PVL) genes. Lineages were determined by pulsed-field gel electrophoresis and multilocus sequence typing (MLST). AD severity was assessed with the Scoring Atopic Dermatitis (SCORAD) index. Among 106 patients, 90 (85%) presented S. aureus isolates in their nares, and 8 also presented the pathogen in their skin infections. Two patients had two positive lesions, making a total of 10 S. aureusisolates from skin infections. Methicillin-resistant S. aureus(MRSA) was detected in 24 (26.6%) patients, and PVL genes were identified in 21 (23.3%), including 6 (75%) of the 8 patients with skin lesions but mainly in patients with severe and moderate SCORAD values (P=0.0095). All 24 MRSA isolates were susceptible to trimethoprim/sulfamethoxazole, while 8 isolates had a minimum inhibitory concentration (MIC) to mupirocin >1024 μg/mL. High lineage diversity was found among the isolates including USA1100/ST30, USA400/ST1, USA800/ST5, ST83, ST188, ST718, ST1635, and ST2791. There was a high prevalence of MRSA and PVL genes among the isolates recovered in this study. PVL genes were found mostly among patients with severe and moderate SCORAD values. These findings can help clinicians improve the therapies and strategies for the management of pediatric patients with AD.
Phenotypic and genotypic detection of virulence factors of Staphylococcus aureus isolated from clinical and subclinical mastitis in cattle and water buffaloes from different farms of Sadat City in Egypt.
Elsayed, Mohamed Sabry; Mahmoud El-Bagoury, Abd Elrahman; Dawoud, Mai Abdallah
To characterize Staphylococcus aureus from clinical and subclinical mastitis and identify virulence factors. Two hundred and two milk samples were collected, 143 from mastitic cattle and buffaloes 94 and 49, respectively, and 59 from apparently healthy cattle and buffaloes 35 and 24, respectively. California mastitis test was applied and positive prevalence were 91.48% and 75.51% for cattle and buffalo with clinical mastitis and 37.14% and 45.83% for cattle and buffalo with subclinical mastitis. S. aureus was isolated from clinically mastitic cattle and buffaloes were 39.29% and 50%, respectively. While, from subclinical mastitic cattle and buffaloes were 80% and 72.73%, respectively. Hemolytic activity was assessed for S. aureus isolated from clinically and subclinical mastitic cases with prevalences of 100% and 56.25%, respectively. Thermo nuclease production from clinically and subclinical mastitic cases was 25% and 56.25%, respectively. Simplex polymerase chain reaction (PCR) conducted on S. aureus using 16S rRNA, clumping factor A, Panton valentine leukocidin, coagulase (Coa), alpha-hemolysin and beta-hemolysin those proved existence in 100%, 46.9%, 65.6%, 100%, 34.4%, and 43.75% of the isolates, respectively. While, multiplex PCR is utilized for detection of enterotoxins and proved that 12.5% was positive for enterotoxine Type D. It is concluded that simplex and multiplex PCR assays can be used as rapid and sensitive diagnostic tools to detect the presence of S. aureus and characterize its virulence factors that help in detection of severity of infection, distribution and stating preventive and control strategies.
Full Text Available Epidemic community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA is associated with more severe and acute forms of osteomyelitis than healthcare-associated (HA- MRSA. Although S. aureus is now recognized as a facultative intracellular pathogen, the contribution of osteoblast invasion by CA-MRSA to the pathogenesis of osteomyelitis is unknown. Using an ex vivo model of intracellular infection of human osteoblasts, we demonstrated that CA-MRSA strains of diverse lineages share an enhanced ability to kill infected osteoblasts compared to HA-MRSA. Cytotoxicity comparisons of CA-MRSA isogenic deletion mutants revealed that phenol-soluble modulins (PSMs, a class of membrane-damaging exoproteins that are expressed at higher levels in CA-MRSA than in HA-MRSA, are involved in this osteoblast killing, whereas other major CA-MRSA virulence determinants, the Panton-Valentine leukocidin and alpha-toxin, are not involved. Similarly, functional agr and sarA regulators, which control the expression of PSMs and alpha-toxin, were required for the expression of the intracellular cytotoxic phenotype by CA-MRSA, whereas the saeRS regulator, which controls the expression of alpha-toxin but not PSMs, had no impact on cytotoxicity. Finally, PSM transcript levels determined by quantitative reverse-transcriptase PCR were significantly higher in CA-MRSA than in HA-MRSA strains and associated with cell damage in MRSA-infected osteoblasts. These findings provide new insights into the pathogenesis of severe CA-MRSA osteomyelitis and unravel a novel virulence strategy of CA-MRSA, based on the invasion and subsequent killing of osteoblasts by PSMs acting as intracellular toxins.
Otter, J A; French, G L
New distinct strains of community-associated meticillin-resistant Staphylococcus aureus (CA-MRSA) have emerged as a cause of infection in previously healthy individuals in community settings. It is important to identify CA-MRSA for clinical management, epidemiological analysis, infection prevention and control, and regulatory reporting, but definitions and nomenclature of these strains are confused. To review attempts to define CA-MRSA and propose a new definition. Non-systematic review. Epidemiological definitions were useful for differentiating CA-MRSA and healthcare-associated (HA)-MRSA strain types in the past. However, although HA-MRSA strain types are rarely transmitted in the community, CA-MRSA strains have started to be transmitted in healthcare facilities, so epidemiological definitions are breaking down. CA-MRSA are community strains of S. aureus that have acquired the meticillin resistance gene, mecA. They are distinct from HA-MRSA and should be defined genetically. This may be done by combining genotypic typing by multi-locus sequence or spa with analysis of the staphylococcal cassette chromosome mec. Carriage of Panton-Valentine leukocidin or antimicrobial susceptibility profiles can be useful indicators of CA-MRSA but should not be used for their definition. For full assessment of their epidemiology, MRSA infections should be characterized as: (1) caused by HA- or CA-MRSA strain types; (2) acquired in community or healthcare settings; and (3) onset in the community or healthcare facility. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.
Development and evaluation of hexaplex PCR for rapid detection of methicillin, cadmium/zinc and antiseptic-resistant staphylococci, with simultaneous identification of PVL-positive and -negative Staphylococcus aureus and coagulase negative staphylococci.
Panda, Sasmita; Kar, Sarita; Choudhury, Ranginee; Sharma, Savitri; Singh, Durg V
We developed a multiplex PCR to detect the presence of methicillin- (mecA), cadmium/zinc-(czrC) and antiseptic-resistant (qacA/B) staphylococci and to identify Panton-Valentine leukocidin (PVL)-positive and -negative Staphylococcus aureus and coagulase-negative staphylococci (CoNS) from infected and healthy eyes. The assay was validated on 177 staphylococci comprising of 55 each of S. aureus and CoNS isolated from infected eyes and five S. aureus and 62 CoNS isolated from healthy eyes and nine direct ocular samples. Nine direct ocular samples for in situ testing consisted of corneal scrapings (4), conjunctiva swabs (2) and others (3). Multiplex PCR result was correlated with genotype data obtained with single PCR and dot-blot assay. The control strains that were positive in multiplex PCR for 16S rRNA, nuc, mecA, pvl, czrC and qacA/B genes were also positive in the dot-blot assay. The specificity of amplified genes obtained with reference strains was further confirmed by DNA sequencing. The single step-hexaplex PCR method can be used for rapid detection of mecA, nuc, pvl, czrC and qacA/B genes in staphylococci with simultaneous identification of PVL-positive and -negative S. aureus and CoNS from a variety of ocular samples. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.
van Strijp Jos AG
Full Text Available Abstract Background Recently, a new livestock-associated methicillin-resistant Staphylococcus aureus (MRSA Sequence Type 398 (ST398 isolate has emerged worldwide. Although there have been reports of invasive disease in humans, MRSA ST398 colonization is much more common in livestock and demonstrates especially high prevalence rates in pigs and calves. The aim of this study was to compare the genome sequence of an ST398 MRSA isolate with other S. aureus genomes in order to identify genetic traits that may explain the success of this particular lineage. Therefore, we determined the whole genome sequence of S0385, an MRSA ST398 isolate from a human case of endocarditis. Results The entire genome sequence of S0385 demonstrated considerable accessory genome content differences relative to other S. aureus genomes. Several mobile genetic elements that confer antibiotic resistance were identified, including a novel composite of an type V (5C2&5 Staphylococcal Chromosome Cassette mec (SCCmec with distinct joining (J regions. The presence of multiple integrative conjugative elements combined with the absence of a type I restriction and modification system on one of the two νSa islands, could enhance horizontal gene transfer in this strain. The ST398 MRSA isolate carries a unique pathogenicity island which encodes homologues of two excreted virulence factors; staphylococcal complement inhibitor (SCIN and von Willebrand factor-binding protein (vWbp. However, several virulence factors such as enterotoxins and phage encoded toxins, including Panton-Valentine leukocidin (PVL, were not identified in this isolate. Conclusions Until now MRSA ST398 isolates did not cause frequent invasive disease in humans, which may be due to the absence of several common virulence factors. However, the proposed enhanced ability of these isolates to acquire mobile elements may lead to the rapid acquisition of determinants which contribute to virulence in human infections.
Samutela, Mulemba Tillika; Kalonda, Annie; Mwansa, James; Lukwesa-Musyani, Chileshe; Mwaba, John; Mumbula, Enoch Mulowa; Mwenya, Darlington; Simulundu, Edgar; Kwenda, Geoffrey
Methicillin-resistant Staphylococcus aureus (MRSA) is globally recognized as an important public health problem. Whereas comprehensive molecular typing data of MRSA strains is available, particularly in Europe, North America and Australia, similar information is very limited in sub-Saharan Africa including Zambia. In this study, thirty two clinical isolates of Staphylococcus aureus , collected at a large referral hospital in Lusaka, Zambia between June 2009 and December 2012 were analysed by Staphylococcal cassette chromosome mec (SCCmec), Staphylococcus protein A gene typing (spa) and detection of the Panton-Valentine Leukocidin genes (pvl) . Three SCC mec types were identified namely SCC mec type IV (65.6%), SCCmec type III (21.9%), SCC mec type I (3.1%). Nine point four percent (9.4%) of the isolates were untypable. Five spa types, which included a novel type, were detected and the most prevalent spa type was t064 (40.6%). Other spa types included spa types t2104 (31.3%), t355 (3.1%) and t1257 (21.9%). The pvl genes were detected in 3 out of 32 isolates. These molecular typing data indicated that the MRSA strains collected in Lusaka were diverse. Although the source of these MRSA was not established, these results stress the need for assessing infection prevention and control procedures at this health-care facility in order to curtail possible nosocomial infections. Furthermore, country-wide surveillance of MRSA in both the community and health-care facilities is recommended for infection prevention and control. To our knowledge, this represents the first study to characterise MRSA using molecular tools in Zambia.
Basanisi, M G; La Bella, G; Nobili, G; Franconieri, I; La Salandra, G
Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen emerging in hospitals as well as community and livestock. MRSA is a significant and costly public health concern because it may enter the human food chain and contaminate milk and dairy products causing foodborne illness. This study aimed to determine the occurrence and the characteristics of MRSA isolated from 3760 samples of milk and dairy products in a previous survey conducted in southern Italy during 2008-2014. Overall out of 484 S. aureus strains isolated, 40 (8.3%) were MRSA and were characterized by spa-typing, Multi-Locus Sequence Typing, SCCmec typing, Staphylococcal enterotoxins (SEs) genes, Panton-Valentine Leukocidin (PVL) genes and ability to form biofilm. The most frequently recovered STs were ST152 (t355-67.5%), followed by ST398 (t899, t108-25%), ST1 (t127-5%) and ST5 (t688-2.5%). All isolates harboured the SCCmec type V (92.5%) or IVa (25%). In one isolate (2.5%), ST398/t899, the SCCmec resulted not detected. Three isolates (7.5%) carried one or more enterotoxin encoding genes (one strain had seg, sei, sem, sen and seo genes; two strains had seh gene). The 50% of isolated strains harboured PVL-encoding genes. Molecular analysis for icaA and icaD genes showed: 72.5% icaA and icaD positive, 25% only icaD gene and one icaA and icaD negative. The detection of MRSA in food of animal origin is a potential health hazard, thus it is necessary monitoring of food-producing animals and improving hygiene standards in food practices in order to reduce the microbiological risk to minimum. Copyright Â© 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
Full Text Available The incidence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA infection is rising in the developed world but appears to be rare in developing countries. One explanation for this difference is that resource poor countries lack the diagnostic microbiology facilities necessary to detect the presence of CA-MRSA carriage and infection.We developed diagnostic microbiology capabilities at the Angkor Hospital for Children, Siem Reap, western Cambodia in January 2006 and in the same month identified a child with severe community-acquired impetigo caused by CA-MRSA. A study was undertaken to identify and describe additional cases presenting between January 2006 and December 2007. Bacterial isolates underwent molecular characterization using multilocus sequence typing, staphylococcal cassette chromosome mec (SCCmec typing, and PCR for the presence of the genes encoding Panton-Valentine Leukocidin (PVL. Seventeen children were identified with CA-MRSA infection, of which 11 had skin and soft tissue infection and 6 had invasive disease. The majority of cases were unrelated in time or place. Molecular characterization identified two independent MRSA clones; fifteen isolates were sequence type (ST 834, SCCmec type IV, PVL gene-negative, and two isolates were ST 121, SCCmec type V, PVL gene-positive.This represents the first ever report of MRSA in Cambodia, spread of which would pose a significant threat to public health. The finding that cases were mostly unrelated in time or place suggests that these were sporadic infections in persons who were CA-MRSA carriers or contacts of carriers, rather than arising in the context of an outbreak.
Abdulgader, Shima M.; Shittu, Adebayo O.; Nicol, Mark P.; Kaba, Mamadou
Methicillin-resistant Staphylococcus aureus (MRSA) infections are a serious global problem, with considerable impact on patients and substantial health care costs. This systematic review provides an overview on the clonal diversity of MRSA, as well as the prevalence of Panton-Valentine leukocidin (PVL)-positive MRSA in Africa. A search on the molecular characterization of MRSA in Africa was conducted by two authors using predefined terms. We screened for articles published in English and French through to October 2014 from five electronic databases. A total of 57 eligible studies were identified. Thirty-four reports from 15 countries provided adequate genotyping data. CC5 is the predominant clonal complex in the healthcare setting in Africa. The hospital-associated MRSA ST239/ST241-III [3A] was identified in nine African countries. This clone was also described with SCCmec type IV [2B] in Algeria and Nigeria, and type V [5C] in Niger. In Africa, the European ST80-IV [2B] clone was limited to Algeria, Egypt and Tunisia. The clonal types ST22-IV [2B], ST36-II [2A], and ST612-IV [2B] were only reported in South Africa. No clear distinctions were observed between MRSA responsible for hospital and community infections. The community clones ST8-IV [2B] and ST88-IV [2B] were reported both in the hospital and community settings in Angola, Cameroon, Gabon, Ghana, Madagascar, Nigeria, and São Tomé and Príncipe. The proportion of PVL-positive MRSA carriage and/or infections ranged from 0.3 to 100% in humans. A number of pandemic clones were identified in Africa. Moreover, some MRSA clones are limited to specific countries or regions. We strongly advocate for more surveillance studies on MRSA in Africa. PMID:25983721
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.
Full Text Available BACKGROUND: Health care workers (HCWs are at the interface between hospitals and communities. The survey for methicillin-resistant Staphylococcus aureus (MRSA carriage among HCWs has mostly been conducted to investigate outbreaks or endemics. Community-associated MRSA are prevalent among children in Taiwan. We conducted this study to better understand the carriage rate of MRSA among pediatricians in non-outbreak situations in Taiwan,. METHODS: A total of 220 pediatricians from Taiwan who attended the annual meeting of Taiwan Pediatric Association in April, 2010 were recruited to participate in this study and were sampled from the nares for the detection of MRSA by polymerase chain reaction (PCR and further by culture. The following molecular analyses were performed, including pulsed-field gel electrophoresis (PFGE, multilocus sequence typing (MLST, typing of staphylococcal cassette chromosome mec (SCCmec and the presence of Panton-Valentine leukocidin (PVL genes. RESULTS: MRSA was detected from 15 attendees (6.8% by PCR. MRSA-colonized attendees had a significantly lower rate (0.041 of working in the medical center, while borderline significantly higher rate of working in the Regional Hospital (p=0.056, than those without MRSA colonization. From those 15 samples, 12 MRSA isolates were identified by culture and molecularly characterized. Three PFGE patterns, two sequence types (ST 59, ST 508, and two SCCmec types (IV and VT were identified, respectively. Five isolates, including three carrying SCCmec types VT, were PVL-positive. All 12 isolates were susceptible to vancomycin, teicoplanin, linezolid, fusidic acid, trimethoprim/sulfamethoxazole, and doxycyclin, and resistant to penicillin. CONCLUSION/SIGNIFICANCE: Around seven percent of pediatricians in Taiwan harbored CA-MRSA in their nares.
Full Text Available Introduction Infections caused by methicillin-resistant Staphylococcus aureus (MRSA present the growing problem in the whole world. Carriage of MRSA is most frequent in the nose, and medical students come in contact both with patients and different persons in the community. Therefore, they may be significant for the transmission of MRSA from hospitals to out- of-hospital communities and vice versa. Objective. The aim of this study was to establish the carriage rate among students of the second, third and fourth year of study at the School of Medicine in Belgrade and to analyze their genotypic and phenotypic characteristics. Methods. In total 533 nasal samples were taken. The samples were incubated in Trypcase-soy broth supplemented with 6.5% NaCl, and thereafter the swabs were inoculated on mannitol salt agar supplemented with 2 µg/mL of oxacillin. The presence of nuc, mecA and Panton-Valentine leukocidin genes was examined by PCR. The characteristics of the MRSA strains were determined using: antibiotic susceptibility testing by Vitek2 System, SCCmec, agr typing and MLST. Results. MRSA was isolated from two of 533 investigated samples (0.37%. MRSA were isolated from the students of the second and third year of study. Profiles of strains were: ST80 (SCCmec type IV, agr type 3 and ST152 (SCCmec type V, agr type 1. MRSA strains were multiresistant. Conclusion. The nasal carriage rate of MRSA in population of medical students of the first year of study in Belgrade is low. Genotypic and phenotypic characteristics of MRSA strains indicate their community origin. MLST typing revealed that isolates belong to ST80 and ST152. [Projekat Ministarstva nauke Republike Srbije, br. ON175039
Blomqvist, Susanne; Leonhardt, Åsa; Arirachakaran, Pratanporn; Carlen, Anette; Dahlén, Gunnar
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 infections and complaints
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
Del Giudice, P; Bes, M; Hubiche, T; Roudière, L; Blanc, V; Lina, G; Vandenesch, F; Etienne, J
Several Panton-Valentin leukocidin-positive clones of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) are spreading worldwide. The European clone ST80-IV is the main CA-MRSA clone in Europe. There is no reported study of the specific clinical manifestations and outcome of skin infections caused by the clone ST80-IV, using strict definitions of skin diseases. Single-centre observational prospective cohort of S. aureus skin infections caused by the clone ST80-IV. From November 1999 to October 2009, we diagnosed skin infections due to the clone ST80-IV in 20 patients (median age 28 years, median 27; range 1-66). All the isolates had all the following characteristics: lukPV, etd and edin gene-positive, agr 3 allele, spa-type t044 and ST80. All the isolates were resistant to beta-lactam agents, kanamycin, tetracycline and fusidic acid. During the study period, the 20 patients had the following manifestations: 19 primary abscesses (18 single abscess and one patient with two), eight furuncles, four folliculitis, one case of cellulitis, one wound infection and one felon. Surgical treatment and drainage was required for all the primary abscesses. The infections occurred mainly in the perineal area (50%). No secondary infections occurred in family members. Despite strict hygiene measures, systemic antibiotics and nasal mupirocine, four patients (20%) had recurrent skin infections over a period of a few months to 6 years. The CA-MRSA clone ST80-IV is responsible for suppurative skin infections such as furuncles and abscesses, which can recur over a period of several years. © 2010 The Authors. Journal of the European Academy of Dermatology and Venereology © 2010 European Academy of Dermatology and Venereology.
Full Text Available Abstract Background: To evaluate the prevalence and microbiological characterization of community-acquired (CA methicillin-resistant Staphylococcus aureus (MRSA nasal carriage in a kindergarten. Methods: Point prevalence study. Nasal swabs were collected from healthy children younger than 7 years of age who were attending a kindergarten in Taipei, Taiwan. A parent questionnaire regarding MRSA risk factors was administered simultaneously. All CA-MRSA colonization isolates were archived for subsequent antimicrobial susceptibility and molecular typing. Results: Of the 68 children who participated in the study, 17 (25% had S. aureus isolated from nasal swabs. Nine (13.2% of the 68 children had CA-MRSA carriage, and none of them had any identified risk factors. Antimicrobial susceptibility testing revealed all of the 9 CA-MRSA colonization isolates had uniformly high resistance (100% to both clindamycin and erythromycin, the macrolide-lincosamide-streptogramin-constitutive phenotype and the ermB gene. Pulsed-field gel electrophoresis revealed 8 (88.9% of 9 CA-MRSA colonization isolates were genetically related and multilocus sequence typing revealed all isolates had sequence type 59. All of the colonization isolates carried the staphylococcal cassette chromosome mec type IV, but none were positive for the Panton-Valentine leukocidin genes. Conclusion: The results of this study suggest that a single predominant CA-MRSA colonization strain featuring high clindamycin resistance circulated in this kindergarten. Additionally, due to the established transmissibility of colonization isolates, the high prevalence of nasal carriage of CA-MRSA among healthy attendees in kindergartens may indicate the accelerated spread of CA-MRSA in the community.
Full Text Available Abstract Background Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA, is an important cause of pyogenic skin and soft tissue infections (SSTIs. The aim of present study is to investigate the molecular characteristic of Staphylococcus aureus isolates isolated from the pus samples from the patients with purulent skin and soft tissue infections in Wenzhou, China. Methods Between December 2002 and June 2008, a total of 111 nonduplicate S. aureus isolates were collected from the pus samples of the patients with SSTIs in a teaching hospital in Wenzhou, China. All the tested isolates were confirmed as S. aureus using a Staph SPA agglutination kit, Gram's stain and a Vitek-60 microbiology analyzer. The homology among the tested isolates was determined by pulsed-field gel electrophoresis (PFGE. Multilocus sequence typing (MLST was used to determine the sequence types (STs of the selected isolates. The genotypes of SCCmec were determined by a multiplex PCR in the MRSA isolates. Panton-Valentine leukocidin (PVL genes and mecA were also determined by another multiplex PCR. Results Among the 111 S. aureus isolates, 48 and 63 isolates were community-acquired and hospital-acquired respectively. Sixty isolates were confirmed as MRSA harboring mecA detected by PCR. A total of 32 PFGE clonal types were obtained by PFGE, with 10 predominant patterns (types A to J. Twenty-five different STs including ST398 and three novel STs were found among 51 selected isolates. The main STs were ST239, ST1018, ST59, ST7 and ST88. Of 60 MRSA isolates, SCCmec II, III, IV and SCCmec V were found in three, 50, three and two isolates, respectively. The positive rates of PVL genes in overall isolates, HA-isolates, CA-isolates, MRSA isolates and MSSA isolates were 23.4% (26/111, 20.6% (13/63, 27.1% (13/48, 21.7% (13/60 and 25.5% (13/51, respectively. Eight (33.3%, 8/24 of 24 CA-MRSA isolates and 5 (13.9%, 5/36 of 36 HA-MRSA isolates were positive for PVL genes
Deurenberg, Ruud H.; Vink, Cornelis; Oudhuis, Guy J.; Mooij, Jascha E.; Driessen, Christel; Coppens, Guy; Craeghs, Jos; De Brauwer, Els; Lemmen, Sebastian; Wagenvoort, Hans; Friedrich, Alexander W.; Scheres, Jacques; Stobberingh, Ellen E.
The Euregio Meuse-Rhine (EMR) is formed by the border regions of Belgium, Germany, and The Netherlands. Cross-border health care requires infection control measures, in particular since the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) differs among the three countries. To investigate the dissemination of MRSA in the EMR, 152 MRSA isolates were characterized by pulsed-field gel electrophoresis (PFGE), SCCmec typing, and multilocus sequence typing. PFGE revealed major clonal groups A, G, L, and Q, suggesting dissemination of MRSA in the EMR. Group A harbored mainly SCCmec type III and sequence types (STs) 239 and 241. The majority of the strains from group G harbored SCCmec type I and ST8 and ST247, whereas most strains from group L carried either SCCmec type IV or type I. Within group L, ST8 and ST228 were found, belonging to clonal complexes 8 and 5, respectively. Most strains from group Q included SCCmec type II and were sequence typed as ST225. Both ST225-MRSA-II and ST241-MRSA-III were novel findings in Germany. In addition, the SCCmec type of two isolates has not been described previously. One strain was classified as SCCmec type III but harbored the pls gene and the dcs region. Another strain was characterized as SCCmec type IV but lacked the dcs region. In addition, one isolate harbored both SCCmec type V and Panton-Valentine leukocidin. Finally, the SCCmec type of the strains was found to be correlated with the antibiotic susceptibility pattern. PMID:16189107
Berla-Kerzhner, E; Biber, A; Parizade, M; Taran, D; Rahav, G; Regev-Yochay, G; Glikman, D
Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are increasingly documented worldwide. We recently identified two major CA-MRSA clones in Israel: USA300 and t991. Here, we assessed clinical outcomes by CA-MRSA clones and the physicians' treatment approach to CA-MRSA infections. All community-onset, clinical MRSA isolates detected during 2011-2013 by Maccabi Healthcare Services were collected and characterized phenotypically and genotypically; data were collected retrospectively from electronic medical records. Of 309 patients with MRSA infections, 64 were identified as CA-MRSA (21 %). Of the CA-MRSA infections, 72 % had skin and soft tissue infections (SSTIs), 38 % were Panton-Valentine leukocidin (PVL)+, the major clone being USA300 (n = 13, 54 %). Of PVL- isolates (n = 40, 62 %), t991 was the major clone. Age was the only predictor for PVL+ CA-MRSA infection (p MRSA had higher incidence of SSTI recurrences (1.061 vs. 0.647 events per patient/per year, p MRSA. USA300 was more common among adults, while t991 was more common among children (p = 0.002). The physician's referral to culture results and susceptibility were the only predictors of appropriate antibiotic therapy (p MRSA isolates caused significantly more recurrences of SSTIs and increased the need for drainage compared with PVL- isolates. Physicians' awareness of CA-MRSA as a cause of SSTIs in the community was suboptimal. Culturing of pus-producing SSTIs is crucial for providing adequate antimicrobials and elucidating MRSA epidemiology.
Prevalence, antibiotic-resistance properties and enterotoxin gene profile of Bacillus cereus strains isolated from milk-based baby foods. Abstract PDF · Vol 16, No 8 (2017) - Articles Methicillin-resistant Staphylococcus aureus isolates from Iranian restaurant food samples: Panton-Valentine Leukocidin, SCCmec phenotypes ...
Kearney, L; O'Connor, C; Fitzpatrick, F; O'Sullivan, J B
A 25-year-old male right-hand dominant warehouse operator presented with two hand infections within 12 weeks both requiring surgical drainage and antimicrobial therapy. Subsequent testing confirmed Panton-Valentine leukocidin-positive Staphylococcus aureus (PVL-SA). This case highlights the need for prompt multidisciplinary management of hand infections to consider, diagnose and manage atypical infections.
Song, Minghui; Bai, Yalong; Xu, Jie; Carter, Michelle Qiu; Shi, Chunlei; Shi, Xianming
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. Copyright © 2014 Elsevier B.V. All rights
Differences between "classical" risk factors for infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and risk factors for nosocomial bloodstream infections caused by multiple clones of the staphylococcal cassette chromosome mec type IV MRSA strain.
Vidal, Paula M; Trindade, Priscila A; Garcia, Tamara O; Pacheco, Renata L; Costa, Silvia F; Reinert, Cristina; Hiramatsu, Keiichi; Mamizuka, Elsa M; Garcia, Cilmara P; Levin, Anna S
the 29 SCCmec type IV MRSA isolates recovered from case patients, none contained the Panton-Valentine leukocidin, gamma-hemolysin, enterotoxin B or C, or toxic shock syndrome toxin-1. All of the isolates contained genes for the LukE-LukD leukocidin and alpha-hemolysin. Genes for enterotoxin A were present in 1 isolate, and genes for beta-hemolysin were present in 3 isolates. "Classical" risk factors do not apply to patients infected with the SCCmec type IV strain of MRSA, which is an important cause of nosocomial bacteremia. This strain infects a patient population that is less ill and has had less frequent invasive procedures than a patient population infected with the multidrug-resistant strain of SCCmec type III MRSA. We found that virulence factors were rare and that Panton-Valentine leukocidin was absent. There were multiple clones of the SCCmec type IV strain in our hospital. Children under 1 year of age were at a higher risk. There was a predominant clone (sequence type 5) in this patient population.
Zurita, Jeannete; Barba, Pedro; Ortega-Paredes, David; Mora, Marcelo; Rivadeneira, Sebastián
The spread of pandemic Staphylococcus aureus clones, mainly methicillin-resistant S. aureus (MRSA), must be kept under surveillance to assemble an accurate, local epidemiological analysis. In Ecuador, the prevalence of the USA300 Latin American variant clone (USA300-LV) is well known; however, there is little information about other circulating clones. The aim of this work was to identify the sequence types (ST) using a Multiple-Locus Variable number tandem repeat Analysis 14-locus genotyping approach. We analyzed 132 S. aureus strains that were recovered from 2005 to 2013 and isolated in several clinical settings in Quito, Ecuador. MRSA isolates composed 46.97% (62/132) of the study population. Within MRSA, 37 isolates were related to the USA300-LV clone (ST8-MRSA-IV, Panton-Valentine Leukocidin [PVL] +) and 10 were related to the Brazilian clone (ST239-MRSA-III, PVL-). Additionally, two isolates (ST5-MRSA-II, PVL-) were related to the New York/Japan clone. One isolate was related to the Pediatric clone (ST5-MRSA-IV, PVL-), one isolate (ST45-MRSA-II, PVL-) was related to the USA600 clone, and one (ST22-MRSA-IV, PVL-) was related to the epidemic UK-EMRSA-15 clone. Moreover, the most prevalent MSSA sequence types were ST8 (11 isolates), ST45 (8 isolates), ST30 (8 isolates), ST5 (7 isolates) and ST22 (6 isolates). Additionally, we found one isolate that was related to the livestock associated S. aureus clone ST398. We conclude that in addition to the high prevalence of clone LV-ST8-MRSA-IV, other epidemic clones are circulating in Quito, such as the Brazilian, Pediatric and New York/Japan clones. The USA600 and UK-EMRSA-15 clones, which were not previously described in Ecuador, were also found. Moreover, we found evidence of the presence of the livestock associated clone ST398 in a hospital environment. Copyright © 2016 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.
Dermota, U; Mueller-Premru, M; Švent-Kučina, N; Petrovič, Ž; Ribič, H; Rupnik, M; Janežič, S; Zdovc, I; Grmek-Košnik, I
The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in Slovenia is poorly documented. The aim of this study was to investigate susceptibility patterns, virulence gene profile and clonality among MRSA isolates with positive screened resistance phenotype for CA-MRSA collected from patients in Slovenia, from January 2010 to December 2010. We included only MRSA isolates that were resistant to cefoxitin and oxacillin, and susceptible to at least two of the following four antibiotics: ciprofloxacin, erythromycin, clindamycin or gentamicin (presumptive CA-MRSA). Altogether 151 isolates fulfilled our screening phenotypic definition, 126 MRSA isolates were classified as CA-MRSA and 25 as HA-MRSA. Thirty-six per cent of them were resistant to ciprofloxacin, 24% to clindamycin, 33% to erythromycin and 13% to gentamicin. The mecA gene was detected in 150 isolates, while the mecC gene only in 1 isolate. The MRSA isolates were classified to 19 different clones. The most prevalent sequence types were ST5 (26.4%), ST45 (25.2%), ST22 (10.6%), ST398 (9.9%), ST8 (5.9%), ST7 (4.6%), ST1 (3.9%), ST152/377 (3.3%), ST228 (2.6%) and ST2883 (1.3%). The ST6, ST9, ST30, ST72, ST88, ST111, ST130, ST225 and ST772 were identified sporadically. The Panton-Valentine leukocidin (PVL) gene was detected in 13 (8.6%) isolates that belonged to ST5, ST7, ST8, ST22, ST72, ST88, ST 152/377 and ST772. Our results show high variability of CA-MRSA circulating in Slovenia and also the presence of LA-MRSA clones. Copyright © 2015 Elsevier GmbH. All rights reserved.
Gosbell, Iain B; Barbagiannakos, Thelma; Neville, Stephen A; Mercer, Joanne L; Vickery, Alison M; O'Brien, Frances G; Coombs, Geoffrey W; Malkowski, Mary J; Pearson, Julie C
To describe clinical features and molecular epidemiology of non-multiresistant methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia. Patients with non-multiresistant MRSA isolated from blood at South Western Area Pathology Service from 1 January 1999 to 31 December 2001 were enrolled. Pulsed field gel electrophoresis, phage typing, and (selected instances) multilocus sequence and staphylococcal cassette chromosome typing was performed. PCR was used to detect Panton-Valentine leukocidin (PVL), toxic shock syndrome toxin-1 (TSST-1), and enterotoxin genes. Sixteen patients were detected: eight with UK EMRSA-15 (ST22-MRSA-IV), three with Oceania (South-West Pacific/Western Samoan phage pattern) (ST30-MRSA-IV), two with WA MRSA-5 (ST8-MRSA-IV), and one each with WA MRSA-1 (ST1-MRSA-IV), Queensland strain (ST93-MRSA-IV), and WA MRSA-15 (ST59-MRSA-IV). Prior hospital admissions occurred with six of the eight patients with UK EMRSA-15, none of the three with Oceania, and three of the five with other strains. Thirteen of 16 patients had underlying disease. Three of the three patients with Oceania strain bacteraemia were Polynesians; 11 of 13 of the others were Caucasians. PVL genes were detected in four of 16 isolates (all Oceania and Queensland strains). entC was detected in two EMRSA-15 strains; entA in one Oceania, two WA MRSA-5 and the WA MRSA-1 strain, with entA and entB in the WA MRSA-15 strain. tst was not detected. Multiple epidemic strains cause non-multiresistant MRSA bacteraemia. Most patients had risk factors. Oceania and Queensland strains possess the PVL gene.
Wang, Jann-Tay; Liao, Chun-Hsing; Fang, Chi-Tai; Chie, Wei-Chu; Lai, Mei-Shu; Lauderdale, Tsai-Ling; Chang, Shan-Chwen
The incidence of and risk factors for acquiring community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) among patients staying in intensive care units (ICUs) remain unclear. We enrolled patients staying in two ICUs at the Far Eastern Memorial Hospital during the period of 1 September 2008 to 30 September 2009 to clarify this issue. Surveillance cultures for MRSA were taken from nostril, sputum or throat, axillae, and the inguinal area in all enrolled patients upon admission to the ICU, every 3 days thereafter, and on the day of discharge from the ICU. For each MRSA isolate, we performed multilocus sequence typing, identified the type of staphylococcal cassette chromosome mec, detected the presence of the Panton-Valentine leukocidin gene, and conducted drug susceptibility tests. Among the 1,906 patients who were screened, 203 patients were carriers of MRSA before their admission to the ICU; 81 patients acquired MRSA during their stay in the ICU, including 31 who acquired CA-MRSA. The incidence rates of newly acquired MRSA and CA-MRSA during the ICU stay were 7.9 and 3.0 per 1,000 patient-days, respectively. Prior usage of antipseudomonal penicillins and antifungals and the presence of a nasogastric tube were found to be independent risk factors for acquiring CA-MRSA during the ICU stay when data for CA-MRSA carriers and patients without carriage of MRSA were compared (P=0.0035, 0.0330, and 0.0262, respectively). Prior usage of carbapenems was found to be a protective factor against acquiring CA-MRSA when data for patients with CA-MRSA and those with health care-associated MRSA acquired during ICU stay were compared (P=0.0240).
Iwao, Yasuhisa; Ishii, Rumiko; Tomita, Yusuke; Shibuya, Yasuhiro; Takano, Tomomi; Hung, Wei-chun; Higuchi, Wataru; Isobe, Hirokazu; Nishiyama, Akihito; Yano, Mio; Matsumoto, Tetsuya; Ogata, Kikuyo; Okubo, Takeshi; Khokhlova, Olga; Ho, Pak-leung; Yamamoto, Tatsuo
Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a major concern worldwide. In the United States, ST8 CA-MRSA with SCCmecIVa (USA300) has been predominant, affecting the entire United States. In this study, we investigated Japanese ST8 CA-MRSA with new SCCmecIV1 (designated ST8 CA-MRSA/J), which has emerged in Japan since 2003. Regarding community spread and infections, ST8 CA-MRSA/J spread in 16.2-34.4% as a major genotype in the community in Japan, and was associated with skin and soft tissue infections (SSTIs), colitis, and invasive infections (sepsis, epidural abscesses, and necrotizing pneumonia), including influenza prodrome cases and athlete infections, similar to USA300. It spread to even public transport and Hong Kong through a Japanese family. Regarding genetic diversity, ST8 CA-MRSA/J included ST and spa variants and was classified into at least three pulsed-field gel electrophoresis types, ST8 Jα to γ. Of those, ST8 Jβ was associated with severe invasive infections. As for genomics, ST8 CA-MRSA/J showed high similarities to USA300, but with marked diversity in accessory genes; e.g., ST8 CA-MRSA/J possessed enhanced cytolytic peptide genes of CA-MRSA, but lacked the Panton-Valentine leukocidin phage and arginine catabolic mobile element, unlike USA300. The unique features of ST8 CA-MRSA/J included a novel mosaic SaPI (designated SaPIj50) carrying the toxic shock syndrome toxin-1 gene with high expression; the evolution included salvage (through recombination) of hospital-acquired MRSA virulence. The data suggest that ST8 CA-MRSA/J has become a successful native clone in Japan, in association with not only SSTIs but also severe invasive infections (posing a threat), requiring attention.
Full Text Available The epidemiology of Staphylococcus aureus in the community in Ghana was never investigated prior to this study. The aims of the study were: i to assess prevalence of nasal S. aureus carriage in Ghanaian people living in an urban and a rural area, and ii to identify phenotypic and genotypic traits of strains isolated from the two communities. Nasal swabs were collected from healthy individuals living in an urban community situated in the suburb of the capital city, Accra (n = 353 and in a rural community situated in the Dangme-West district (n = 234. The overall prevalence of nasal carriage was 21% with a significantly higher prevalence in the urban (28% than in the rural community (11% (p<0.0001. The levels of antimicrobial resistance were generally low (<5% except for penicillin (91% and tetracycline (25%. The only two (0.3% MRSA carriers were individuals living in the urban area and had been exposed to hospitals within the last 12 months prior to sampling. Resistance to tetracycline (p = 0.0009 and presence of Panton-Valentine leukocidin (PVL gene (p = 0.02 were significantly higher among isolates from the rural community compared to isolates from the urban community. Eleven MLST clonal complexes (CC were detected based on spa typing of the 124 S. aureus isolates from the two communities: CC8 (n = 36, CC152 (n = 21, CC45 (n = 21, CC15 (n = 18, CC121 (n = 6, CC97 (n = 6, CC30 (n = 5, CC5 (n = 5, CC508 (n = 4, CC9 (n = 1, and CC707 (n = 1. CC8 and CC45 were less frequent in the rural area than in the urban area (p = 0.02. These results reveal remarkable differences regarding carriage prevalence, tetracycline resistance, PVL content and clonal distribution of S. aureus in the two study populations. Future research may be required to establish whether such differences in nasal S. aureus carriage are linked to socio-economic differences between urban and rural communities in this
Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA has emerged as a prevalent pathogen of necrotizing fasciitis (NF in Taiwan. A four-year NF cases and clinical and genetic differences between hospital acquired (HA- and community-acquired (CA-MRSA infection and isolates were investigated. Methods A retrospective study of 247 NF cases in 2004-2008 and antimicrobial susceptibilities, staphylococcal chromosomal cassette mec (SCCmec types, pulsed field gel electrophoresis (PFGE patterns, virulence factors, and multilocus sequence typing (MLST of 16 NF-associated MRSA in 2008 were also evaluated. Results In 247 cases, 42 microbial species were identified. S. aureus was the major prevalent pathogen and MRSA accounted for 19.8% of NF cases. Most patients had many coexisting medical conditions, including diabetes mellitus, followed by hypertension, chronic azotemia and chronic hepatic disease in order of decreasing prevalence. Patients with MRSA infection tended to have more severe clinical outcomes in terms of amputation rate (p S. aureus or non-S. aureus infection. NF patients infected by HA-MRSA had a significantly higher amputation rate, comorbidity, C-reactive protein level, and involvement of lower extremity than those infected by CA-MRSA. In addition to over 90% of MRSA resistant to erythromycin and clindamycin, HA-MRSA was more resistant than CA-MRSA to trimethoprim-sulfamethoxazole (45.8% vs. 4%. ST59/pulsotype C/SCCmec IV and ST239/pulsotype A/SCCmec III isolates were the most prevalent CA- and HA-MRSA, respectively in 16 isolates obtained in 2008. In contrast to the gene for γ-hemolysin found in all MRSA, the gene for Panton-Valentine leukocidin was only identified in ST59 MRSA isolates. Other three virulence factors TSST-1, ETA, and ETB were occasionally identified in MRSA isolates tested. Conclusion NF patients with MRSA infection, especially HA-MRSA infection, had more severe clinical outcomes than those infected by
Okolie, Charles Emeka; Wooldridge, Karl G; Turner, David P J; Cockayne, Alan; James, Richard
Staphylococcal toxicity and antibiotic resistance (STAAR) have been menacing public health. Although vancomycin-resistant Staphylococcus aureus (VRSA) is currently not as widespread as methicillin-resistant S. aureus (MRSA), genome evolution of MRSA into VRSA, including strains engineered within the same patient under anti-staphylococcal therapy, may build up to future public health concern. To further complicate diagnosis, infection control and anti-microbial chemotherapy, non-sterile sites such as the nares and the skin could contain both S. aureus and coagulase-negative staphylococci (CoNS), either of which could harbour mecA the gene driving staphylococcal methicillin-resistance and required for MRSA-VRSA evolution. A new heptaplex PCR assay has been developed which simultaneously detects seven markers for: i) eubacteria (16S rRNA), ii) Staphylococcus genus (tuf), iii) Staphylococcus aureus (spa), iv) CoNS (cns), v) Panton-Valentine leukocidin (pvl), vi) methicillin resistance (mecA), and vii) vancomycin resistance (vanA). Following successful validation using 255 reference bacterial strains, applicability to analyse clinical samples was evaluated by direct amplification in spiked blood cultures (n = 89) which returned 100 % specificity, negative and positive predictive values. The new assay has LoD of 1.0x10(3) CFU/mL for the 16S rRNA marker and 1.0x10(4) CFU/mL for six other markers and completes cycling in less than one hour. The speed, sensitivity (100 %), NPV (100 %) and PPV (100 %) suggest the new heptaplex PCR assay could be easily integrated into a routine diagnostic microbiology workflow. Detection of the cns marker allows for unique identification of CoNS in mono-microbial and in poly-microbial samples containing mixtures of CoNS and S. aureus without recourse to the conventional elimination approach which is ambiguous. In addition to the SA-CoNS differential diagnostic essence of the new assay, inclusion of vanA primers will allow
Chen, Yi-Wen; Wang, Hong; Hupert, Mateusz; Soper, Steven A
Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of hospital-acquired (HA-MRSA) infection worldwide. As a result, the rapid and specific detection of MRSA is crucial not only for early prevention of disease spread, but also for the effective treatment of these infections. We report here an integrated modular-based microfluidic system for MRSA identification, which can carry out the multi-step assay used for MRSA identification in a single disposable fluidic cartridge. The multi-step assay included PCR amplification of the mecA gene harboring methicillin resistance loci that can provide information on drug susceptibility, ligase detection reaction (LDR) to generate fluorescent ligation products appended with a zip-code complement that directs the ligation product to a particular address on a universal array containing zip-code probes and a universal DNA array, which consisted of a planar waveguide for evanescent excitation. The fluidic cartridge design was based on a modular format, in which certain steps of the molecular processing pipeline were poised on a module made from a thermoplastic. The cartridge was comprised of a module interconnected to a fluidic motherboard configured in a 3-dimensional network; the motherboard was made from polycarbonate, PC, and was used for PCR and LDR, while the module was made from poly(methylmethacrylate), PMMA, and contained an air-embedded waveguide serving as the support for the universal array. Fluid handling, thermal management and optical readout hardware were situated off-chip and configured into a small footprint instrument. In this work, the cartridge was used to carry out a multiplexed PCR/LDR coupled with the universal array allowed for simultaneous detection of five genes that encode for 16S ribosomal RNA (SG16S), protein A (spa), the femA protein of S. epidermidis (femA), the virulence factor of Panton-Valentine leukocidin (PVL) and the gene that confers methicillin resistance (mecA). Results
Wettstein Rosenkranz, K; Rothenanger, E; Brodard, I; Collaud, A; Overesch, G; Bigler, B; Marschall, J; Perreten, V
We screened a total of 340 veterinarians (including general practitioners, small animal practitioners, large animal practitioners, veterinarians working in different veterinary services or industry), and 29 veterinary assistants for nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus pseudintermedius (MRSP) at the 2012 Swiss veterinary annual meeting. MRSA isolates (n = 14) were detected in 3.8 % (95 % CI 2.1 - 6.3 %) of the participants whereas MRSP was not detected. Large animal practitioners were carriers of livestock-associated MRSA (LA-MRSA) ST398-t011-V (n = 2), ST398-t011-IV (n = 4), and ST398-t034-V (n = 1). On the other hand, participants working with small animals harbored human healthcare-associated MRSA (HCA-MRSA) which belonged to epidemic lineages ST225-t003-II (n = 2), ST225-t014-II (n = 1), ST5-t002-II (n = 2), ST5-t283-IV (n = 1), and ST88-t186-IV (n = 1). HCA-MRSA harbored virulence factors such as enterotoxins, β-hemolysin converting phage and leukocidins. None of the MRSA isolates carried Panton-Valentine leukocidin (PVL). In addition to the methicillin resistance gene mecA, LA-MRSA ST398 isolates generally contained additional antibiotic resistance genes conferring resistance to tetracycline [tet(M) and tet(K)], trimethoprim [dfrK, dfrG], and the aminoglycosides gentamicin and kanamycin [aac(6')-Ie - aph(2')-Ia]. On the other hand, HCA-MRSA ST5 and ST225 mainly contained genes conferring resistance to the macrolide, lincosamide and streptogramin B antibiotics [erm(A)], to spectinomycin [ant(9)-Ia], amikacin and tobramycin [ant(4')-Ia], and to fluoroquinolones [amino acid substitutions in GrlA (S84L) and GyrA (S80F and S81P)]. MRSA carriage may represent an occupational risk and veterinarians should be aware of possible MRSA colonization and potential for developing infection or for transmitting these strains. Professional exposure to animals should be reported upon hospitalization and before medical
Kyra Y L Chua
Full Text Available Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA USA300 has spread rapidly across North America, and CA-MRSA is also increasing in Australia. However, the dominant Australian CA-MRSA strain, ST93-IV [2B] appears distantly related to USA300 despite strikingly similar clinical and epidemiological profiles. Here, we compared the virulence of a recent Australian ST93 isolate (JKD6159 to other MRSA, including USA300, and found that JKD6159 was the most virulent in a mouse skin infection model. We fully sequenced the genome of JKD6159 and confirmed that JKD6159 is a distinct clone with 7616 single nucleotide polymorphisms (SNPs distinguishing this strain from all other S. aureus genomes. Despite its high virulence there were surprisingly few virulence determinants. However, genes encoding α-hemolysin, Panton-Valentine leukocidin (PVL and α-type phenol soluble modulins were present. Genome comparisons revealed 32 additional CDS in JKD6159 but none appeared to encode new virulence factors, suggesting that this clone's enhanced pathogenicity could lie within subtler genome changes, such as SNPs within regulatory genes. To investigate the role of accessory genome elements in CA-MRSA epidemiology, we next sequenced three additional Australian non-ST93 CA-MRSA strains and compared them with JKD6159, 19 completed S. aureus genomes and 59 additional S. aureus genomes for which unassembled genome sequence data was publicly available (82 genomes in total. These comparisons showed that despite its distinctive genotype, JKD6159 and other CA-MRSA clones (including USA300 share a conserved repertoire of three notable accessory elements (SSCmecIV, PVL prophage, and pMW2. This study demonstrates that the genetically distinct ST93 CA-MRSA from Australia is highly virulent. Our comparisons of geographically and genetically diverse CA-MRSA genomes suggest that apparent convergent evolution in CA-MRSA may be better explained by the rapid
Molecular Evolutionary Pathways toward Two Successful Community-Associated but Multidrug-Resistant ST59 Methicillin-Resistant Staphylococcus aureus Lineages in Taiwan: Dynamic Modes of Mobile Genetic Element Salvages.
Full Text Available Clonal complex 59 (CC59 Staphylococcus aureus in Taiwan includes both methicillin-susceptible S. aureus (MSSA and methicillin-resistant S. aureus (MRSA. As the most prominent community-associated MRSA (CA-MRSA in Taiwan, CC59 has two major clones characterized as PVL-negative SCCmec IV (carrying the staphylococcal cassette chromosome mec IV but Panton-Valentine leukocidin-negative and PVL-positive SCCmec V (5C2&5. We investigated the drug resistance, phylogeny and the distribution and sequence variation of SCCmec, staphylococcal bacteriophage φSA3, genomic island νSaβ and MES (an enterococcal mobile genetic element conferring multidrug resistance in 195 CC59 S. aureus. Sequencing and PCR mapping revealed that all of the CC59/SCCmec V (5C2&5 MRSA strains had acquired MESPM1 or its segregants, and obtained a φSA3-related fragment in νSaβ. In contrast, MES6272-2 and MES4578, which showed gentamicin resistance that was not encoded by MESPM1, were dominant in SCCmec IVg MRSA. Translocation of a whole φSA3 into νSaβ instead of only a φSA3-related fragment was common in SCCmec IVg MRSA. However, the non-subtype-g SCCmec IV MRSA (SCCmec IVa is the major still carried MES and νSaβ structures similar to those in SCCmec V (5C2&5 MRSA. A minimum spanning tree constructed by multiple-locus variable-number tandem repeat analysis revealed that SCCmec IVg MRSA and SCCmec V (5C2&5 MRSA grouped respectively in two major clades. The CC59 MSSA was equally distributed among the two clades, while the non-subtype-g SCCmec IV MRSA mostly clustered with SCCmec V (5C2&5 MRSA. Our findings strongly suggest that CC59 MSSA acquired divergent mobile genetic elements and evolved to SCCmec IVg MRSA and SCCmec V (5C2&5 MRSA/non-subtype-g SCCmec IV MRSA independently. The evolutionary history of CC59 S. aureus explains how mobile genetic elements increase the antimicrobial resistance and virulence and contribute to the success of CA-MRSA in Taiwan.
Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA has of late emerged as a cause of community-acquired infections among immunocompetent adults without risk factors. Skin and soft tissue infections represent the majority of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA clinical presentations, whilst invasive and life-threatening illness like necrotizing pneumonia, necrotizing fasciitis, pyomyositis, osteomyelitis and sepsis syndrome are less common. Although more widely described in the pediatric age group, the occurrence of CA-MRSA osteomyelitis in adults is an uncommonly reported entity. Case presentation We describe an invasive CA-MRSA infection in a 28 year-old previously healthy male, manifesting with bacteraemia, osteomyelitis of femur, pyomyositis and septic arthritis of the knee. Initially a preliminary diagnosis of osteosarcoma was suggested by imaging studies and patient underwent a bone biopsy. MRSA was subsequently isolated from blood cultures taken on day of admission, bone, tissue and pus cultures. Incision and drainage of abscess was performed and patient was treated with vancomycin, with fusidic acid added later. It took 6 months for the inflammatory markers to normalize, warranting 6-months of anti-MRSA therapy. Patient was a fervent deer hunter and we speculate that he acquired this infection from extensive direct contact with deer. Molecular characterization of this isolate showed that it belonged to multilocus sequence type (MLST ST30 and exhibited the staphylococcal chromosome cassette mec (SCCmec type IV, staphylococcus protein A (spa type t019, accessory gene regulator (agr type III and dru type dt10m. This strain harbored Panton-Valentine leukocidin (pvl genes together with 3 other virulent genes; sei (enterotoxin, hlg (hemolysin and fnbA (fibronectin binding protein. Conclusion This case study alerts physicians that beyond the most commonly encountered skin and soft tissue
Mayra Alejandra Machuca
Full Text Available BACKGROUND: Staphylococcus aureus is among the most common global nosocomial pathogens. The emergence and spread of methicillin-resistant Staphylococcus aureus (MRSA is a public health problem worldwide that causes nosocomial and community infections. The goals of this study were to establish the clonal complexes (CC of the isolates of MRSA obtained from pediatric patients in a university hospital in Colombia and to investigate its molecular characteristics based on the virulence genes and the genes of staphylococcal toxins and adhesins. METHODS: A total of 53 MRSA isolates from pediatric patients with local or systemic infections were collected. The MRSA isolates were typed based on the SCCmec, MLST, spa and agr genes. The molecular characterization included the detection of Panton-Valentine Leukocidin, superantigenic and exfoliative toxins, and adhesin genes. The correlation between the molecular types identified and the profile of virulence factors was determined for all isolates. RESULTS: Four CC were identified, including CC8, CC5, CC80 and CC78. The ST8-MRSA-IVc-agrI was the predominant clone among the isolates, followed by the ST5-MRSA-I-agrII and ST5-MRSA-IVc-agrII clones. Twelve spa types were identified, of which t10796 and t10799 were new repeat sequences. The isolates were carriers of toxin genes, and hlg (100%, sek (92% and pvl (88% were the most frequent. Ten toxin gene profiles were observed, and the most frequent were seq-sek-hlg (22.6%, sek-hlg (22.6%, seb-seq-sek-hlg (18.9% and seb-sek-hlg (15.1%. The adhesion genes were present in most of the MRSA isolates, including the following: clf-A (89%, clf-B (87%, fnb-A (83% and ica (83%. The majority of the strains carried SCCmec-IVc and were identified as causing nosocomial infection. No significant association between a molecular type and the virulence factors was found. CONCLUSION: Four major MRSA clone complexes were identified among the isolates. ST8-MRSA-IVc-agrI pvl+ (USA300-LV
Machuca, Mayra Alejandra; Sosa, Luis Miguel; González, Clara Isabel
Staphylococcus aureus is among the most common global nosocomial pathogens. The emergence and spread of methicillin-resistant Staphylococcus aureus (MRSA) is a public health problem worldwide that causes nosocomial and community infections. The goals of this study were to establish the clonal complexes (CC) of the isolates of MRSA obtained from pediatric patients in a university hospital in Colombia and to investigate its molecular characteristics based on the virulence genes and the genes of staphylococcal toxins and adhesins. A total of 53 MRSA isolates from pediatric patients with local or systemic infections were collected. The MRSA isolates were typed based on the SCCmec, MLST, spa and agr genes. The molecular characterization included the detection of Panton-Valentine Leukocidin, superantigenic and exfoliative toxins, and adhesin genes. The correlation between the molecular types identified and the profile of virulence factors was determined for all isolates. Four CC were identified, including CC8, CC5, CC80 and CC78. The ST8-MRSA-IVc-agrI was the predominant clone among the isolates, followed by the ST5-MRSA-I-agrII and ST5-MRSA-IVc-agrII clones. Twelve spa types were identified, of which t10796 and t10799 were new repeat sequences. The isolates were carriers of toxin genes, and hlg (100%), sek (92%) and pvl (88%) were the most frequent. Ten toxin gene profiles were observed, and the most frequent were seq-sek-hlg (22.6%), sek-hlg (22.6%), seb-seq-sek-hlg (18.9%) and seb-sek-hlg (15.1%). The adhesion genes were present in most of the MRSA isolates, including the following: clf-A (89%), clf-B (87%), fnb-A (83%) and ica (83%). The majority of the strains carried SCCmec-IVc and were identified as causing nosocomial infection. No significant association between a molecular type and the virulence factors was found. Four major MRSA clone complexes were identified among the isolates. ST8-MRSA-IVc-agrI pvl+ (USA300-LV) was the most frequent, confirming the presence
Normanno, Giovanni; Dambrosio, Angela; Lorusso, Vanessa; Samoilis, Georgios; Di Taranto, Pietro; Parisi, Antonio
Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen present in the hospital environment (HA-MRSA), in the community (CA-MRSA) and in livestock, including pigs (LA-MRSA). MRSA may enter the human food chain during slaughtering and may infect humans coming into direct contact with pigs or pork products. This study aimed to determine the prevalence and characteristics of MRSA isolated from pigs and workers at industrial abattoirs in southern Italy. A total of 215 pig nasal swabs were screened for the presence of MRSA using PCR. An MRSA isolate was detected from each mecA/nuc PCR-positive sample and characterized by spa-typing, Multi-Locus Sequence Typing, SCC-mec and Panton-Valentine Leukocidin (PVL), and also tested for the production of staphylococcal enterotoxins (SEs). Eighty-one MRSA isolates (37.6%) were obtained from the 215 pig nasal swabs; 37 of these isolates were further characterized, and showed 18 different spa-types and 8 different STs. The most frequently recovered STs were ST398 (CC398-t034, t011, t899, t1939 - 43.2%) followed by ST8 (CC8-t008, t064, t2953, t5270 - 24.3%) and ST1 (CC1-t127, t174, t2207 - 10.8%). Nine MRSA isolates were obtained from the 113 human swabs; the isolates showed 5 different spa-types and 5 different STs, including the novel ST2794 (t159). The most representative STs recovered were ST1 (CC1-t127) and ST398 (CC398-t034) (33.3%). None of the MRSA isolates showed the ability to produce SEs and PVL and all resulted resistant to two or more classes of antimicrobials. This study shows the great genetic diversity of MRSA strains in slaughtered pigs and in abattoir employees in Italy, and clearly demonstrates the need for improved hygiene standards to reduce the risk of occupational and food-borne infection linked to the handling/consumption of raw pork containing MRSA. Copyright © 2015 Elsevier Ltd. All rights reserved.
Full Text Available Staphylococcus aureus is a globally important human pathogen, especially among children and immunocompromised patients. The emergence and spread of community-associated methicillin-resistant S. aureus (CA-MRSA has become a serious public health problem worldwide. The aim of this study was to investigate the prevalence, molecular characteristics and virulence profiles of CA-MRSA infections from pediatric patients in a university hospital in Shanghai, China. A total of eighty CA-MRSA isolates were collected from July 2012 to December 2013 in Shanghai Children's Medical Center and analyzed by multilocus sequence typing, staphylococcus chromosomal cassette mec(SCCmec typing, and spa typing. The detection of Panton-Valentine Leukocidin(pvl, superantigenic and exfoliative toxins, and adhesin genes was also performed. Overall, 16 distinct sequence types (STs were identified among the 80 isolates. Among them, ST59 was found to be the most prevalent, followed by ST398 (11.3%, 9/80 and ST88 (8.8%,7/80. SCCmec types IV and V were observed, at 60% and 40% respectively. Thirty spa types were identified, spa t437 (23.8% was the most predominant type. All 80 isolates exhibited carriage of at least 4 virulence genes. Thirty-four (42.5%, 34/80 isolates harbored ≥10 tested virulence genes. Adhesion genes were present in most of the MRSA isolates, including the following: icaA (100%, clfA (100%, sdrC (95%, and sdrE (63.8%. The prevalence of pvl gene was 20%, and multidrug resistance was observed in 36% of all strains. In addition, ST59-MRSA-IV with t437 accounted for 21.3% of occurrences, making it the most prevalent clone. Isolates that were carriers of toxin genes, and hla(100% and hlg(87.5% were the most frequent. In conclusion, simultaneous carriage of multiple virulence genes and genetically considerable diversity were very common among CA-MRSA from pediatric patients in Shanghai. ST59-MRSA-IV with t437 was still the most predominant type. The combination
Full Text Available A bacterial insertion sequence (IS is a mobile DNA sequence carrying only the transposase gene (tnp that acts as a mutator to disrupt genes, alter gene expressions, and cause genomic rearrangements. "Canonical" ISs have historically been characterized by their terminal inverted repeats (IRs, which may form a stem-loop structure, and duplications of a short (non-IR target sequence at both ends, called target site duplications (TSDs. The IS distributions and virulence potentials of Staphylococcus aureus genomes in familial infection cases are unclear. Here, we determined the complete circular genome sequences of familial strains from a Panton-Valentine leukocidin (PVL-positive ST50/agr4 S. aureus (GN infection of a 4-year old boy with skin abscesses. The genomes of the patient strain (GN1 and parent strain (GN3 were rich for "canonical" IS1272 with terminal IRs, both having 13 commonly-existing copies (ce-IS1272. Moreover, GN1 had a newly-inserted IS1272 (ni-IS1272 on the PVL-converting prophage, while GN3 had two copies of ni-IS1272 within the DNA helicase gene and near rot. The GN3 genome also had a small deletion. The targets of ni-IS1272 transposition were IR structures, in contrast with previous "canonical" ISs. There were no TSDs. Based on a database search, the targets for ce-IS1272 were IRs or "non-IRs". IS1272 included a larger structure with tandem duplications of the left (IRL side sequence; tnp included minor cases of a long fusion form and truncated form. One ce-IS1272 was associated with the segments responsible for immune evasion and drug resistance. Regarding virulence, GN1 expressed cytolytic peptides (phenol-soluble modulin α and δ-hemolysin and PVL more strongly than some other familial strains. These results suggest that IS1272 transposes through an IR-replacing mechanism, with an irreversible process unlike that of "canonical" transpositions, resulting in genomic variations, and that, among the familial strains, the patient
Feltrin, Fabiola; Alba, Patricia; Kraushaar, Britta; Ianzano, Angela; Argudín, María Angeles; Di Matteo, Paola; Porrero, María Concepción; Aarestrup, Frank M; Butaye, Patrick; Franco, Alessia; Battisti, Antonio
Pandemic methicillin-resistant Staphylococcus aureus (MRSA) clonal complex 97 (CC97) lineages originated from livestock-to-human host jumps. In recent years, CC97 has become one of the major MRSA lineages detected in Italian farmed animals. The aim of this study was to characterize and analyze differences in MRSA and methicillin-susceptible S. aureus (MSSA) mainly of swine and bovine origins. Forty-seven CC97 isolates, 35 MRSA isolates, and 6 MSSA isolates from different Italian pig and cattle holdings; 5 pig MRSA isolates from Germany; and 1 human MSSA isolate from Spain were characterized by macrorestriction pulsed-field gel electrophoresis (PFGE) analysis, multilocus sequence typing (MLST), spa typing, staphylococcal cassette chromosome mec (SCCmec) typing, and antimicrobial resistance pattern analysis. Virulence and resistance genes were investigated by PCR and microarray analysis. Most of the isolates were of SCCmec type V (SCCmec V), except for two German MRSA isolates (SCCmec III). Five main clusters were identified by PFGE, with the German isolates (clusters I and II) showing 60.5% similarity with the Italian isolates, most of which (68.1%) grouped into cluster V. All CC97 isolates were Panton-Valentine leukocidin (PVL) negative, and a few (n = 7) tested positive for sak or scn. All MRSA isolates were multidrug resistant (MDR), and the main features were erm(B)- or erm(C)-mediated (n = 18) macrolide-lincosamide-streptogramin B resistance, vga(A)-mediated (n = 37) pleuromutilin resistance, fluoroquinolone resistance (n = 33), tet(K) in 32/37 tet(M)-positive isolates, and blaZ in almost all MRSA isolates. Few host-associated differences were detected among CC97 MRSA isolates: their extensive MDR nature in both pigs and dairy cattle may be a consequence of a spillback from pigs of a MRSA lineage that originated in cattle as MSSA and needs further investigation. Measures should be implemented at the farm level to prevent spillover to humans in intensive farming
Egyir, Beverly; Guardabassi, Luca; Sørum, Marit
The objective of this study was to determine the antimicrobial susceptibility patterns and clonal diversity of clinical Staphylococcus aureus isolates from Ghana. A total of 308 S. aureus isolates from six healthcare institutions located across Northern, Central and Southern Ghana were......-positive S. aureus in Africa, low prevalence of antimicrobial resistance and high diversity of MRSA lineages in Ghana compared to developed countries and other African countries. The detection of known pandemic MRSA clones in the absence of routine MRSA identification in most Ghanaian clinical microbiology...... characterized by antibiotyping, spa typing and PCR detection of Panton Valentine leukocin (PVL) genes. Methicillin-resistant S. aureus (MRSA) were confirmed by PCR detection of mecA gene and further characterized by SCCmec and multi-locus sequence typing (MLST). The prevalence of antimicrobial resistance...
Full Text Available Sequence type (ST 59 is an epidemic lineage of community-associated (CA methicillin-resistant Staphylococcus aureus (MRSA isolates. Taiwanese CA-MRSA isolates belong to ST59 and can be grouped into 2 distinct clones, a virulent Taiwan clone and a commensal Asian-Pacific clone. The Taiwan clone carries the Panton-Valentine leukocidin (PVL genes and the staphylococcal chromosomal cassette mec (SCCmec VT, and is frequently isolated from patients with severe disease. The Asian-Pacific clone is PVL-negative, carries SCCmec IV, and a frequent colonizer of healthy children. Isolates of both clones were characterized by their ability to adhere to respiratory A549 cells, cytotoxicity to human neutrophils, and nasal colonization of a murine and murine sepsis models. Genome variation was determined by polymerase chain reaction of selected virulence factors and by multi-strain whole genome microarray. Additionally, the expression of selected factors was compared between the 2 clones. The Taiwan clone showed a much higher cytotoxicity to the human neutrophils and caused more severe septic infections with a high mortality rate in the murine model. The clones were indistinguishable in their adhesion to A549 cells and persistence of murine nasal colonization. The microarray data revealed that the Taiwan clone had lost the ø3-prophage that integrates into the β-hemolysin gene and includes staphylokinase- and enterotoxin P-encoding genes, but had retained the genes for human immune evasion, scn and chps. Production of the virulence factors did not differ significantly in the 2 clonal groups, although more α-toxin was expressed in Taiwan clone isolates from pneumonia patients. In conclusion, the Taiwan CA-MRSA clone was distinguished by enhanced virulence in both humans and an animal infection model. The evolutionary acquisition of PVL, the higher expression of α-toxin, and possibly the loss of a large portion of the β-hemolysin-converting prophage likely
Full Text Available Abstract Background Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA is a global healthcare problem. The purpose of this study was to characterize CA-MRSA clones and their distribution in Kuwait hospitals. Methods In total, 135 CA-MRSA isolates, carrying the SCCmec IV or V genetic elements, isolated in eight hospitals were characterized using antibiogram, pulsed-field gel electrophoresis, multilocus sequence typing, and carriage of genes for Panton-Valentine Leukocidin (PVL, capsular polysaccharides types (cap 5 and 8, accessory genes regulators (agr, Staphylococcal enterotoxins (SE and toxic shock syndrome toxin 1 (tst. Results They were susceptible to vancomycin, teicoplanin and linezolid but resistant to kanamycin (62%, fusidic acid (42.2%, tetracycline (39.3%, erythromycin and clindamycin (21.5%, gentamicin (5.9%, streptomycin (6.7%, trimethoprim (5.9%, mupirocin (6.6% and cadmium acetate (82.2%. They consisted of 10 pulsotypes with the majority belonging to PFGE type I (51.1%, type II (22.2%, type IV (13.3% and type III (3.7%. They belonged to 10 sequence types (ST comprising ST80 (51.1%, ST30 (22.2%, ST5 (14.1%, ST1 (4.45, ST6 (3.7%, ST88 (1.5%, ST834 (1.5%, ST8 (0.7%, ST46 (0.7% and ST950 (0.7%. Genes for PVL, cap 8, cap 5 and agr III, agr I and agr II were detected in 61.5%, 77.3%, 20.7% and 62.2%, 17% and 8.1% of the isolates respectively. Nine (6.7% isolates contained tst while 103 isolates were positive for SE genes with sei (63.0%, seg (41.5% and sed (29.6% as the common SE genes. Conclusions ST80-SCCmecIV was the most common CA-MRSA clone in Kuwait hospitals presenting new challenges for infection control.
Sato, Tomomi; Usui, Masaru; Konishi, Noriko; Kai, Akemi; Matsui, Hidehito; Hanaki, Hideaki; Tamura, Yutaka
Methicillin-resistant Staphylococcus aureus (MRSA) is a pervasive healthcare-acquired (HA) pathogen with recent emergence as a community-acquired (CA) pathogen. To elucidate whether meat mediates MRSA transmission between animals and humans in Japan, this study examined MRSA isolates from retail meat (n = 8), cows with mastitis (n = 7), and humans (HA-MRSA = 46 and CA-MRSA = 54) by molecular typing, virulence gene analyses, and antimicrobial susceptibility testing. MRSA isolates from retail meat were classified into sequence type (ST) 8/spa type t1767 (n = 4), ST8/t4133 (n = 1), ST59/t3385 (n = 1), ST88/t375 (n = 1), and ST509/t375 (n = 1). All seven MRSA isolates from cows with mastitis were ST8/t1767. 46 HA-MRSA were clonal complex (CC) 5, divided into t002 (n = 30), t045 (n = 12), and t7455 (n = 4). 54 CA-MRSA were classified into 6 different CCs: CC1 (n = 14), CC5 (n = 7), CC8 (n = 29), CC45 (n = 1), CC89 (n = 1), CC509 (n = 1), and into 16 different spa types including newly identified t17177, t17193, and t17194. The majority were CC8/t1767 (n = 16). CC of one CA-MRSA isolate (spa type t1767) was not classified. Among 41 CC8 MRSA (five from meat, seven from cows with mastitis, and 29 CA-MRSA), 14 ST8/SCCmec IVl isolates (three from meat, one from a cow with mastitis, and 10 CA-MRSA) had identical pulsed-field gel electrophoresis patterns and similar spa type (t1767, t4133, and t17177), and were typed as CA-MRSA/J (ST8/SCCmec IVl, positive for sec + sel + tst but negative for Panton-Valentine leukocidin and the arginine catabolic mobile element). These results suggest that there is a transmission cycle of CA-MRSA/J among meat, cows, and humans in Japan, although it is unclear whether the origin is cow.
Lemaître, Chloé; Angoulvant, François; Gabor, Flaviu; Makhoul, Juliette; Bonacorsi, Stéphane; Naudin, Jérôme; Alison, Marianne; Faye, Albert; Bingen, Edouard; Lorrot, Mathie
Forty-one children hospitalized for necrotizing pneumonia were retrospectively analyzed. Necrotizing pneumonia represented 0.8% of community-acquired pneumonia and 6% of hospitalized community-acquired pneumonia. The chest radiograph revealed necrosis on admission in onethird of cases. Twenty-one cases (51%) were documented, including 13 Staphylococcus aureus, all Panton-Valentine leukocidin positive, 7 Streptococcus pneumoniae and 1 Fusobacterium nucleatum.
Full Text Available Abstract Background Community-Associated Methicillin Resistant Staphylococcus aureus (CA-MRSA has traditionally been related to skin and soft tissue infections in healthy young patients. However, it has now emerged as responsible for severe infections worldwide, for which vancomycin is one of the mainstays of treatment. Infective endocarditis (IE due to CA-MRSA with heterogeneous vancomycin-intermediate susceptibility-(h-VISA has been recently reported, associated to an epidemic USA 300 CA-MRSA clone. Case Presentation We describe the occurrence of h-VISA phenotype in a case of IE caused by a strain belonging to an epidemic CA-MRSA clone, distinct from USA300, for the first time in Argentina. The isolate h-VISA (SaB2 was recovered from a patient with persistent bacteraemia after a 7-day therapy with vancomycin, which evolved to fatal case of IE complicated with brain abscesses. The initial isolate-(SaB1 was fully vancomycin susceptible (VSSA. Although MRSA SaB2 was vancomycin susceptible (≤2 μg/ml by MIC (agar and broth dilution, E-test and VITEK 2, a slight increase of MIC values between SaB1 and SaB2 isolates was detected by the four MIC methods, particularly for teicoplanin. Moreover, Sab2 was classified as h-VISA by three different screening methods [MHA5T-screening agar, Macromethod-E-test-(MET and by GRD E-test] and confirmed by population analysis profile-(PAP. In addition, a significant increase in cell-wall thickness was revealed for SaB2 by electron microscopy. Molecular typing showed that both strains, SaB1 and SaB2, belonged to ST5 lineage, carried SCCmecIV, lacked Panton-Valentine leukocidin-(PVL genes and had indistinguishable PFGE patterns (subtype I2, thereby confirming their isogenic nature. In addition, they were clonally related to the epidemic CA-MRSA clone (pulsotype I detected in our country. Conclusions This report demonstrates the ability of this epidemic CA-MRSA clone, disseminated in some regions of Argentina, to
Oliveira, Pollianna S; Souza, Simone G; Campos, Guilherme B; da Silva, Danilo C C; Sousa, Daniel S; Araújo, Suerda P F; Ferreira, Laiziane P; Santos, Verena M; Amorim, Aline T; Santos, Angelita M O G; Timenetsky, Jorge; Cruz, Mariluze P; Yatsuda, Regiane; Marques, Lucas M
Currently, hospital infection is a serious public health problem, and several factors may influence the occurrence of these infections, including the presence of insects, which are carriers of multidrug-resistant bacterial species. The aim of this study was to isolate staphylococci carried by insects in two public hospitals of Vitoria da Conquista, Bahia and to identify the resistance profile, pathogenicity and efficacy of disinfection of the premises. A total of 91 insects were collected in 21 strategic points of these hospitals, and 32 isolated strains of Staphylococcus aureus were isolated. Based on antibiogram and Minimum Inhibitory Concentration results, 95% of these strains were susceptible to oxacillin. These strains were also evaluated for the presence of resistance genes encoding resistance to oxacillin/methicillin by polymerase chain reaction, but the sample was negative for this gene. Pathogenicity tests were performed in vitro biofilm formation induced by glucose, where it was found that eight (27.58%) strains were classified as biofilm producers and 21 (72.4%) as stronger producers. In addition, we performed PCR for their virulence genes: Sea (enterotoxin A), SEB (B), Sec (C), PVL (Panton-Valentine Leukocidin), ClfA (clumping factor A) and Spa (protein A). Of these, Sea, Spa PVL were positive in 7 (21.8%), 2 (6.3%) and 1 (3.1%) samples, respectively. The analysis of cytokine induction in the inflammatory response of J774 macrophages by isolates from the two hospitals did not show statistical difference at the levels of IL-6, TNF-α, IL-1 and IL-10 production. In addition, we verified the antimicrobial activity of disinfecting agents on these strains, quaternary ammonium, 0.5% sodium hypochlorite, 1% sodium hypochlorite, 2% sodium hypochlorite, 2% glutaraldehyde, Lysoform(®), 70% alcohol solution of chlorhexidine digluconate, 2% peracetic acid, and 100% vinegar. Resistance was seen in only for the following two disinfectants: 70% alcohol in 31 (96
Pollianna S. Oliveira
Full Text Available Currently, hospital infection is a serious public health problem, and several factors may influence the occurrence of these infections, including the presence of insects, which are carriers of multidrug-resistant bacterial species. The aim of this study was to isolate staphylococci carried by insects in two public hospitals of Vitoria da Conquista, Bahia and to identify the resistance profile, pathogenicity and efficacy of disinfection of the premises. A total of 91 insects were collected in 21 strategic points of these hospitals, and 32 isolated strains ofStaphylococcus aureus were isolated. Based on antibiogram and Minimum Inhibitory Concentration results, 95% of these strains were susceptible to oxacillin. These strains were also evaluated for the presence of resistance genes encoding resistance to oxacillin/methicillin by polymerase chain reaction, but the sample was negative for this gene. Pathogenicity tests were performed in vitro biofilm formation induced by glucose, where it was found that eight (27.58% strains were classified as biofilm producers and 21 (72.4% as stronger producers. In addition, we performed PCR for their virulence genes: Sea (enterotoxin A, SEB (B, Sec (C, PVL (Panton-Valentine Leukocidin, ClfA (clumping factor A and Spa (protein A. Of these, Sea, Spa PVL were positive in 7 (21.8%, 2 (6.3% and 1 (3.1% samples, respectively. The analysis of cytokine induction in the inflammatory response of J774 macrophages by isolates from the two hospitals did not show statistical difference at the levels of IL-6, TNF-α, IL-1 and IL-10 production. In addition, we verified the antimicrobial activity of disinfecting agents on these strains, quaternary ammonium, 0.5% sodium hypochlorite, 1% sodium hypochlorite, 2% sodium hypochlorite, 2% glutaraldehyde, Lysoform®, 70% alcohol solution of chlorhexidine digluconate, 2% peracetic acid, and 100% vinegar. Resistance was seen in only for the following two disinfectants: 70% alcohol in 31
Full Text Available According to the EARS-Net surveillance data, Portugal has the highest prevalence of nosocomial methicillin-resistant Staphylococcus aureus (MRSA in Europe, but the information on MRSA in the community is very scarce and the links between the hospital and community are not known. In this study we aimed to understand the events associated to the recent sharp increase in MRSA frequency in Portugal and to evaluate how this has shaped MRSA epidemiology in the community. With this purpose, 180 nosocomial MRSA isolates recovered from infection in two time periods and 14 MRSA isolates recovered from 89 samples of skin and soft tissue infections (SSTI were analyzed by pulsed-field gel electrophoresis (PFGE, staphylococcal chromosome cassette mec (SCCmec typing, spa typing and multilocus sequence typing (MLST. All isolates were also screened for the presence of Panton Valentine leukocidin (PVL and arginine catabolic mobile element (ACME by PCR. The results showed that ST22-IVh, accounting for 72% of the nosocomial isolates, was the major clone circulating in the hospital in 2010, having replaced two previous dominant clones in 1993, the Iberian (ST247-I and Portuguese (ST239-III variant clones. Moreover in 2010, three clones belonging to CC5 (ST105-II, ST125-IVc and ST5-IVc accounted for 20% of the isolates and may represent the beginning of new waves of MRSA in this hospital. Interestingly, more than half of the MRSA isolates (8/14 causing SSTI in people attending healthcare centers in Portugal belonged to the most predominant clones found in the hospital, namely ST22-IVh (n = 4, ST5-IVc (n = 2 and ST105-II (n = 1. Other clones found included ST5-V (n = 6 and ST8-VI (n = 1. None of the MRSA isolates carried PVL and only five isolates (ST5-V-t179 carried ACME type II. The emergence and spread of EMRSA-15 may be associated to the observed increase in MRSA frequency in the hospital and the consequent spillover of MRSA into the community.
Pollianna S. Oliveira
Full Text Available Currently, hospital infection is a serious public health problem, and several factors may influence the occurrence of these infections, including the presence of insects, which are carriers of multidrug-resistant bacterial species. The aim of this study was to isolate staphylococci carried by insects in two public hospitals of Vitoria da Conquista, Bahia and to identify the resistance profile, pathogenicity and efficacy of disinfection of the premises. A total of 91 insects were collected in 21 strategic points of these hospitals, and 32 isolated strains of Staphylococcus aureus were isolated. Based on antibiogram and Minimum Inhibitory Concentration results, 95% of these strains were susceptible to oxacillin. These strains were also evaluated for the presence of resistance genes encoding resistance to oxacillin/methicillin by polymerase chain reaction, but the sample was negative for this gene. Pathogenicity tests were performed in vitro biofilm formation induced by glucose, where it was found that eight (27.58% strains were classified as biofilm producers and 21 (72.4% as stronger producers. In addition, we performed PCR for their virulence genes: Sea (enterotoxin A, SEB (B, Sec (C, PVL (Panton-Valentine Leukocidin, ClfA (clumping factor A and Spa (protein A. Of these, Sea, Spa PVL were positive in 7 (21.8%, 2 (6.3% and 1 (3.1% samples, respectively. The analysis of cytokine induction in the inflammatory response of J774 macrophages by isolates from the two hospitals did not show statistical difference at the levels of IL-6, TNF-α, IL-1 and IL-10 production. In addition, we verified the antimicrobial activity of disinfecting agents on these strains, quaternary ammonium, 0.5% sodium hypochlorite, 1% sodium hypochlorite, 2% sodium hypochlorite, 2% glutaraldehyde, Lysoform®, 70% alcohol solution of chlorhexidine digluconate, 2% peracetic acid, and 100% vinegar. Resistance was seen in only for the following two disinfectants: 70% alcohol in 31
Mayra Alejandra Machuca
Full Text Available Introducción. Staphylococcus aureus resistente a la meticilina (SARM es un agente frecuente de infección en la población pediátrica. Aunque inicialmente las cepas de SARM estaban restringidas a los hospitales, se han reportado a nivel mundial brotes de infección por SARM en individuos sin factores de riesgo y, actualmente, SARM es una causa frecuente de infecciones hospitalarias y comunitarias. Objetivo. Describir la relación entre las características moleculares de aislamientos de SARM (casete cromosómico estafilocócico mec SCCmec y leucocidina Panton-Valentine y el origen de la infección y su presentación clínica en pacientes pediátricos del Hospital Universitario de Santander en Bucaramanga, Colombia. Materiales y métodos. Se incluyeron 43 aislamientos de SARM obtenidos de niños hospitalizados. La clasificación del SCCmec (I-V y la subclasificación del SCCmec-IV se realizaron en todos los aislamientos. Además, los genes de la leucocidina Panton-Valentine se detectaron mediante amplificación por PCR. Las características moleculares fueron asociadas con las características clínicas de cada paciente. Resultados. Entre los 43 SARM tipificados, el SCCmec-IVc fue el más frecuente con 77 %, seguido por el SCCmec-I con 16 % y el SCCmec-IVa con 2 %. Tres aislamientos no pudieron ser tipificados. Los genes de la leucocidina Panton Valentine se detectaron en 88 % de los SARM en aislamientos portadores del SCCmec-IVc/IVa y el SCCmec-I. Los SARM SCCmec-IV positivos para la leucocidina Panton-Valentine se asociaron con infecciones adquiridas en la comunidad (47 % y en el hospital (53 % con compromiso de piel y tejidos blandos, y en los casos más graves, con compromiso osteoarticular. Conclusiones. Estos resultados sugieren la presencia de cepas SARM-CO (SCCmec-IV positiva para PVL causantes de infecciones adquiridas en la comunidad y en el medio hospitalario en pacientes pediátricos en Colombia.
Veena Kumari H
Full Text Available Septic cavernous sinus thrombosis (CST is an uncommon clinical syndrome. Although Staphylococcus aureus (S aureus is the most common bacterial pathogen causing CST, it is infrequent as a cause of meningitis. We report the first case of CST and meningitis from Bengaluru, Karnataka, caused by community-acquired epidemic methicillin resistant Staphylococcus aureus-15 (EMRSA-15, in a previously healthy individual without known risk factors; the patient recovered following treatment with vancomycin. The isolate was genotyped as belonging to staphylococcal cassette chromosome mec type IV and sequence type 22 and carried the panton-valentine leucocidin gene. It is the first Indian EMRSA-15 disease isolate from a case of meningitis. EMRSA-15 has been a major problem in hospitals in UK and it is a cause for great concern in Indian hospitals too.
Sit, Pik San; Teh, Cindy Shuan Ju; Idris, Nuryana; Sam, I-Ching; Syed Omar, Sharifah Faridah; Sulaiman, Helmi; Thong, Kwai Lin; Kamarulzaman, Adeeba; Ponnampalavanar, Sasheela
Methicillin-resistant Staphylococcus aureus (MRSA) is an established pathogen that causes hospital- and community-acquired infections worldwide. The prevalence rate of MRSA infections were reported to be the highest in Asia. As there is limited epidemiological study being done in Malaysia, this study aimed to determine the prevalence of MRSA infection and the molecular characteristics of MRSA bacteraemia. Two hundred and nine MRSA strains from year 2011 to 2012 were collected from a tertiary teaching hospital in Malaysia. The strains were characterized by antimicrobial susceptibility testing, staphylococcal cassette chromosome mec (SCCmec) typing, detection of Panton-Valentine leukocidin (PVL) gene, multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Patient's demographic and clinical data were collected and correlated with molecular data by statistical analysis. Male gender and patient >50 years of age (p MRSA acquisition. Fifty-nine percent of MRSA strains were HA-MRSA that carried SCCmec type II, III, IV and V while 31% were CA-MRSA strains with SCCmec III, IV and V. The prevalence of PVL gene among 2011 MRSA strains was 5.3% and no PVL gene was detected in 2012 MRSA strains. All of the strains were sensitive to vancomycin. However, vancomycin MIC creep phenomenon was demonstrated by the increased number of MRSA strains with MIC ≥1.5 μg/mL (p = 0.008) between 2011 and 2012. Skin disease (p = 0.034) and SCCmec type III (p = 0.0001) were found to be significantly associated with high vancomycin MIC. Forty-four percent of MRSA strains from blood, were further subtyped by MLST and PFGE. Most of the bacteraemia cases were primary bacteraemia and the common comorbidities were diabetes, hypertension and chronic kidney disease. The predominant pulsotype was pulsotype C exhibited by SCCmec III-ST239. This is a first study in Malaysia that reported the occurrence of MRSA clones such as SCCmec V-ST5, untypeable-ST508, SCCmec IV-ST1
Mohamed, N A; Ramli, S; Amin, N N Z; Sulaiman, W S W; Isahak, I; Jamaluddin, T Z M T; Salleh, N M
Nasal colonisation of S. aureus in healthy children was 18% to 30%. One to three percent of them were colonised by Methicillin-resistant Staphlycoccus aureus (MRSA). Although MRSA infection has become increasingly reported, population-based S. aureus and MRSA colonisation estimates are lacking. The main objective of this study was to determine the prevalence of S. aureus carriage among children. Nasal samples for S. aureus culture were obtained from 250 children from three kindergartens in the Klang Valley, after consent was obtained from the children and their parents. Swabs were transported in Stuart medium, and inoculated on mannitol-salt agar within four hours of collection. Identification and disk diffusion test were done according to guidelines. Polymerase chain reaction was done on MRSA isolates for the presence of mecA and lukS/FPV genes. Overall prevalence of S. aureus and MRSA carriage were 19.2% (48/250) and 1.6% (4/250) respectively. mecA gene was present in all isolates, 50% isolates carried Panton-Valentine leucocidin (PVL) gene. Sccmec type I was found in 2 isolates and the remaining isolates has Sccmec type V. The prevalence of S. aureus and MRSA carriage were similar to other studies. However, risk of contracting severe infection might be higher due to presence of PVL gene in half of the MRSA isolates.
Amissah, Nana Ama; Chlebowicz, Monika A; Ablordey, Anthony; Tetteh, Caitlin S; Prah, Isaac; van der Werf, Tjip S; Friedrich, Alex W; van Dijl, Jan Maarten; Stienstra, Ymkje; Rossen, John W
Buruli ulcer (BU) is a necrotizing infection of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. BU wounds may also be colonized with other microorganisms including Staphylococcus aureus. This study aimed to characterize the virulence factors of S. aureus isolated from BU patients. Previously sequenced genomes of 21 S. aureus isolates from BU patients were screened for the presence of virulence genes. The results show that all S. aureus isolates harbored on their core genomes genes for known virulence factors like α-hemolysin, and the α- and β-phenol soluble modulins. Besides the core genome virulence genes, mobile genetic elements (MGEs), i.e. prophages, genomic islands, pathogenicity islands and a Staphylococcal cassette chromosome (SCC) were found to carry different combinations of virulence factors, among them genes that are known to encode factors that promote immune evasion, superantigens and Panton-Valentine Leucocidin. The present observations imply that the S. aureus isolates from BU patients harbor a diverse repertoire of virulence genes that may enhance bacterial survival and persistence in the wound environment and potentially contribute to delayed wound healing. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.
Mercieri, Marco; Di Rosa, Roberta; Pantosti, Annalisa; De Blasi, Roberto Alberto; Pinto, Giovanni; Arcioni, Roberto
We present a case of community-acquired methicillin-resistant Staphylococcus aureus necrotizing pneumonia, Panton-Valentine leukocidin positive, in a woman at 14 weeks of pregnancy. To our knowledge, this is the first case reporting this critical lung infection occurring during an early phase of pregnancy. This case study alerts physicians to the increasing worldwide spread of these uncommon yet virulent and potentially lethal infections. In our patient, antibiotic therapy with linezolid plus rifampin started at 14 weeks of pregnancy had a successful outcome without inducing toxicity or teratogenesis in the fetus.
Tomatis, Carla; Baroni, María R; Mendosa, María A; Nagel, Alicia; Mollerach, Analia; Alvarez, Claudia; Zurbriggen, Maria Laura; Cristobal, Sabrina; Segovia, Glenda; Méndez, Emilce de Los A
Staphylococcus aureus is a pathogen associated a different kind of infection. Molecular markers are useful tools to study microbial epidemiology. Twenty two methicillin-resistant S. aureus (MRSA) and 23 methicillin-susceptible S. aureus (MSSA) were studied by mecA gene, SCCmec cassette, Panton Valentine leucocidin (PVL) and spa polymorphism. The clinical data patients were analyzed. MSSA was prevalent in samples different from skin and soft tissue (SST) and in hospitalized patients, whereas MRSA in SST. SCCmec type IV was predominant, followed by type I. Low presence of PVL was found. In MRSA 11 different types of spa were detected, t019 was the most frequent and associated with outpatient, 17 types were found in MSSA and t189 was prevalent. spa t002 was present in MSSA and MRSA. We found 11 types of spa not reported in our country. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.
Full Text Available Staphylococcus aureus es un importante patógeno involucrado en una serie de infecciones e intoxicaciones, presenta múltiples factores de virulencia y su impacto se incrementa por su notable resistencia a los antimicrobianos. Objetivo: Determinar la frecuencia de Staphylococcus aureus meticilino resistente adquiridos en la comunidad, en hospitales de Lima- Perú. Material y métodos: Se realizó un estudio descriptivo multicéntrico. La resistencia a meticilina se determinó por el método Oxacillin Agar Screen. El origen de la cepa fue determinado mediante los criterios de los CDC; la Leucocidina de Panton Valentine fue identificada por métodos moleculares. Resultados: Se aislaron 276 cepas de Staphylococcus aureus, 160 fueron resistentes a meticilina (58%, 9 de ellas fueron identificadas como adquiridas en la comunidad (5,6%. La PVL fue identificada en 25 cepas (9,1%, 14 fueron MSSA y 11 MRSA, de éstas últimas solo 4 fueron MRSAcom, 7 fueron MRSAhosp (p<0,001. Conclusiones: El estudio revela niveles elevados de resistencia a meticilina, pero niveles bajos de MRSAcom. En nuestro medio la presencia de PVL no constituiría un marcador para la identificación de los MRSAcom. (Rev Med Hered 2010;21:4-10.
Infecciones adquiridas en la comunidad por Staphylococcus aureus resistente a meticilina en un hospital de agudos Community-acquired methicillin-resistant Staphylococcus aureus infections in a hospital for acute diseases
Full Text Available Staphylococcus aureus resistente a meticilina (SAMR es uno de los principales agentes asociados a infecciones intrahospitalarias; sin embargo, en los últimos años ha surgido como un patógeno emergente de la comunidad, causando infecciones graves, principalmente en jóvenes. Se describen 33 casos de infecciones por SAMR de origen comunitario, diagnosticadas entre mayo de 2005 y junio de 2006 en el HIGA "Eva Perón". Se estudiaron retrospectivamente los aislamientos; se confirmó la resistencia a meticilina mediante la detección del gen mecA, se investigó la presencia de genes que codifican dos factores de virulencia (leucocidina de Panton-Valentine -LPV- y g-hemolisina y el tipo de casete mec mediante PCR. Todos los pacientes se encontraban sanos previamente. Cuatro pacientes menores de 12 años presentaron bacteriemia, uno con neumonía grave y los 3 restantes con infección osteoarticular; todos los pacientes mayores de 12 años presentaron infecciones de piel y partes blandas sin compromiso sistémico. Se constató la presencia de casete mec tipo IV en todos los aislamientos; la resistencia a meticilina no se acompañó de resistencia a otros antimicrobianos; los aislamientos fueron portadores de genes que codifican para LPV y para g-hemolisina. Es importante considerar la presencia de estas cepas de origen comunitario a fin de elaborar estrategias para su correcto tratamiento.Methicillin- resistant Staphylococcus aureus (MRSA is one of the most prevalent pathogens associated with nosocomial infections. However, most recently, MRSA has arisen as an emerging community pathogen, causing serious infections, mainly among young patients. We herein describe 33 cases of infections caused by community-acquired MRSA (CMRSA, diagnosed between May 2005 and June 2006, at "Eva Perón" Hospital. The isolations were retrospectively studied. Methicillin resistance was confirmed by means of the detection of the mecA gene, and the genes for two virulence
Luis Miguel Sosa Ávila
Full Text Available Introducción: La emergencia de infecciones, en niños, por Staphylococcus aureus meticilino resistente adquirido en comunidad (SAMR-AC constituye un problema de salud pública en varios países del mundo, sin embargo, en nuestro país hay pocos reportes sobre las características clínicas, factores de riesgo y características moleculares. Materiales y métodos Estudio descriptivo que comparó el comportamiento clínico y epidemiológico de las infecciones por S. aureus meticilino resistente y S. aureus meticilino sensible. Se detectaron los genes mecA, lukS-PV y lukF-PV por amplificación y se determinó la resistencia a antimicrobianos. Resultados: De las 39 infecciones por S. aureus entre enero de 2008 y junio de 2009, el 60% fueron por S. aureus meticilino resistente, con mayor proporción de lactantes y uso previo de antibióticos en el grupo meticilino resistente. Predominó la localización osteoarticular (54% seguida de piel y tejidos blandos (41%. En los meticilino resistentes, el gen mecA y lukS-PV y lukF-PV se detectaron en el 93% y 86% respectivamente. En el grupo meticilino resistentes y leucocidina de Panton Valentine positiva, fueron más frecuentes los abscesos subcutáneos, una mayor respuesta inflamatoria y susceptibilidad a la mayoría de los antibióticos. Conclusión: Reportamos la presencia de infecciones por SAMR - AC (LPV +, con susceptibilidad a la mayoría de los antibióticos en nuestro medio, con abscesos como foco clínico predominante y una mayor respuesta inflamatoria. Salud UIS 2010; 42: 248-255Introduction: The emergence of the infection by community-acquired methicillin-resistant S. aureus, in children, is a public health problem in many countries of the world, however, in Colombia, local dates about the clinical features, risk factors and molecular characteristic are scarce. Materials and methods: This descriptive study compared the clinical and epidemiological behavior of infections by methicillin
Blumental, S; Deplano, A; Jourdain, S; De Mendonça, R; Hallin, M; Nonhoff, C; Rottiers, S; Vergison, A; Denis, O
It is common wisdom that persistent carriage of Staphylococcus aureus is more frequent in young children than in adults. The objectives of this study were to assess the S. aureus temporal carriage pattern among a healthy community of pre-school children, with concomitant description of genotype diversity, toxin-encoding genes and antibiotic resistance. Among 333 children 3-6 years of age, S. aureus nasopharyngeal carriage was assessed over one school year by culture of three sequential nasopharyngeal aspirates. Identification, methicillin resistance and toxin production profile were determined by PCR. Genotyping was performed by spa sequencing and multilocus sequence typing (MLST). Out of 830 samples collected, 286 (34%) yielded S. aureus from 185 carriers (55%). Based on consecutive genotype analysis, only 40/268 (15%) children could be classified as persistent carriers, and the remaining 118 (44%) showed intermittent carriage. spa typing revealed 82 types clustered into 13 spa clonal complexes (CCs). Fourteen strains isolated from 11 (3%) children were methicillin-resistant S. aureus (MRSA), half of these strains belonged to the commonly hospital-associated spa t008-ST8-SCCmec IV. Methicillin-susceptible S. aureus (MSSA) were genotypically more diverse. Toxic shock syndrome toxin and egc1/2 complexes were highly prevalent (24%). Contrastingly, Panton-Valentine leucocidin (PVL) was carried only by three MSSA strains (0.6% of children). Exfoliative toxins were detected in 10 (3.5%) MSSA strains, of which 5 were related to the impetigo clone CC121. Although S. aureus nasopharyngeal carriage was high among healthy pre-school children, persistent carriage seems to be less frequent than previously reported. The prevalence of MRSA carriage was 3%, but was not associated with PVL.
Feng, Ye; Chen, Hsiu-Ling; Chen, Chih-Jung; Chen, Chyi-Liang; Chiu, Cheng-Hsun
Sequence type (ST) 59 is an epidemic lineage of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in Asia. Two ST59 clones are prevalent in Taiwan: the Taiwan clone (TW) causes severe infections, whereas the Asian-Pacific clone (AP) is usually commensal. In this study, we sequenced the genome and transcriptome of the representative strains of these two clones and found their differences to focus on three mobile genetic elements: TW carries SCCmec Type V T , Panton-Valentine leucocidin (PVL)-encoding prophage ΦSa2, whereas AP carries SCCmec Type IV and staphylokinase (SAK)-encoding prophage ΦSa3. The anti-virulent role of SAK was confirmed using murine skin and bloodstream infection models. ΦSa3 usually integrates into the hlb gene, but in AP was found to be integrated at the genomic island νSaβ. The mutation of the attB site "TGTATCCAAACTGG" to "TGTATCCGAATTGG" led to a failure in the integration of ΦSa3 in hlb, prompting atypical integration at other sites. The sak gene possessed remarkably different patterns of distribution among the different STs of S. aureus. We conclude that the atypical integration of ΦSa3 may help S. aureus adapt to the human host habitat and that the subsequent loss of ΦSa3 contributes toward the development of a virulent CA-MRSA lineage for wider horizontal transmission. Copyright © 2017 Elsevier B.V. All rights reserved.
Okolie, Charles E
The genus Staphylococcus includes pathogenic and non-pathogenic facultative anaerobes. Due to the plethora of virulence factors encoded in its genome, the species Staphylococcus aureus is known to be the most pathogenic. S. aureus strains harboring genes encoding virulence and antibiotic resistance are of public health importance. In clinical samples, however, pathogenic S. aureus is often mixed with putatively less pathogenic coagulase-negative staphylococci (CoNS), both of which can harbor mecA, the genetic driver for staphylococcal methicillin-resistance. In this chapter, the detailed practical procedure for operating a real-time pentaplex PCR assay in blood cultures is described. The pentaplex real-time PCR assay simultaneously detects markers for the presence of bacteria (16S rRNA), coagulase-negative staphylococcus (cns), S. aureus (spa), Panton-Valentine leukocidin (pvl), and methicillin resistance (mecA).
Haque, Abdul; Haque, Asma; Saeed, Muhammad; Azhar, Aysha; Rasool, Samreen; Shan, Sidra; Ehsan, Beenish; Nisar, Zohaib
Emergence of methicillin resistant Staphylococcus aureus (MRSA) is a major medical problem of current era. These bacteria are resistant to most drugs and rapid diagnosis can provide a clear guideline to clinicians. They possess specific virulence factors and relevant information can be very useful. We designed this study to develop multiplex PCRs to provide rapid information. We studied 60 Staphylococcus aureus isolates and detected methicillin resistance by cefoxitin sensitivity and targeting of mecA gene. After initial studies with uniplex PCRs we optimized two multiplex PCRs with highly reproducible results. The first multiplex PCR was developed to confirm genus, species and methicillin resistance simultaneously, and the second multiplex PCR was for screening of virulence factors. We found 38.33% isolates as methicillin resistant. α -toxin, the major cytotoxic factor, was detected in 40% whereas β-hemolysin was found in 25% cases. Panton Valentine leucocidin was detected in 8.33% and toxic shock syndrome toxin in5% cases. The results of uniplex and multiplex PCRs were highly compatible. These two multiplex PCRs when run simultaneously can provide vital information about methicillin resistance and virulence status of the isolate within a few hours as compared to several days needed by routine procedures.
Antimicrobial susceptibility of Staphylococcus aureus isolated from children with impetigo in China from 2003 to 2007 shows community-associated methicillin-resistant Staphylococcus aureus to be uncommon and heterogeneous.
Liu, Y; Kong, F; Zhang, X; Brown, M; Ma, L; Yang, Y
The number of patients with impetigo caused by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has been increasing. To investigate the antimicrobial susceptibility of S. aureus causing impetigo in children in China from 2003 to 2007 and further characterize isolates of CA-MRSA. We examined 984 S. aureus isolates for antimicrobial susceptibility to 11 antimicrobials using the agar dilution method. CA-MRSA isolates were analysed for Panton-Valentine leucocidin (PVL) genes, and staphylococcal cassette chromosome mec (SCCmec) typing was performed. The largest proportion (94.5%) of strains were resistant to penicillin, followed by erythromycin (86.2%) and clindamycin (69.6%). In total 772 of 984 (78.5%) S. aureus strains were multiresistant. The incidence of CA-MRSA was 1.1%, with a high rate of resistance to clindamycin (90.9%) and tetracycline (72.7%), but all were susceptible to ciprofloxacin. The susceptibility profiles of MRSA to other antimicrobial agents were similar to those of methicillin-sensitive S. aureus (MSSA). None of the S. aureus strains were resistant to vancomycin and fusidic acid; moreover, only one strain was resistant to mupirocin. Typing of the SCCmec showed that 54.5% were type IV, 18.2% were type V and 9.1% were type VI. All the PVL-positive CA-MRSA carried SCCmec type IV. CA-MRSA is still relatively uncommon and heterogeneous in children in China. Penicillin and erythromycin are no longer appropriate agents. Effective antibiotic agents for patients with impetigo are mupirocin and fusidic acid.
Hisata, Ken; Ito, Teruyo; Matsunaga, Nobuaki; Komatsu, Mitsutaka; Jin, Jingxun; Li, Shanshuang; Watanabe, Shinya; Shimizu, Toshiaki; Hiramatsu, Keiichi
The proportion of MRSA strains that cause skin and soft infections has recently increased. In 3 months we have characterized 17 MRSA strains isolated from children with impetigo at a Japanese hospital. Seventeen MRSA strains belonged to 7 clones defined by clonal complex (CC) in MLST genotype and type of SCCmec, which were rarely identified among healthcare-associated MRSA: CC 91-SCCmecIIb (4 strains); CC91-SCCmecIIn (2 strains); CC91-SCCmecIVa (2 strains); CC91-SCCmecV (4 strains); CC88-SCCmecIVg (3 strains); CC1-SCCmecIVc (1 strain); and CC5-SCCmecIVn (1 strain). Although one strain belonged to CC5, which has been commonly identified in healthcare-associated MRSA, it did not carry type II SCCmec, but carried type IV SCCmec. Fourteen of the 17 strains carried exfoliative toxin a or b gene, and none carried Panton-Valentine leukocidine gene. Furthermore, we determined the entire nucleotide sequences of two type V SCCmec elements carried by strains JCSC5952, a CC91 strain, and TSGH17, a Taiwanese CC59 strain. The structure of SCCmecJCSC5952 was more than 99% homologous in nucleotide identity with those of Taiwanese PVL-positive ST59 MRSA strains TSGH17 and PM1, which were designated as type V (5C2&5). Identification of multiple MRSA clones distinct from those disseminating at the hospital suggests that MRSA strains might be emerging in the community from MSSA strains by acquiring SCCmec elements on various occasions. Carriage of the similar type V(5C2&5) SCCmec element by strains of distinct genetic backgrounds, CC91 and CC59, suggested horizontal transfer of the SCCmec element.
Grosz, Magdalena; Kolter, Julia; Paprotka, Kerstin; Winkler, Ann-Cathrin; Schäfer, Daniel; Chatterjee, Som Subra; Geiger, Tobias; Wolz, Christiane; Ohlsen, Knut; Otto, Michael; Rudel, Thomas; Sinha, Bhanu; Fraunholz, Martin
Staphylococcus aureus is a Gram-positive human pathogen that is readily internalized by professional phagocytes such as macrophages and neutrophils but also by non-professional phagocytes such as epithelial or endothelial cells. Intracellular bacteria have been proposed to play a role in evasion of the innate immune system and may also lead to dissemination within migrating phagocytes. Further, S. aureus efficiently lyses host cells with a battery of cytolytic toxins. Recently, phenol-soluble modulins (PSM) have been identified to comprise a genus-specific family of cytolytic peptides. Of these the PSMα peptides have been implicated in killing polymorphonuclear leucocytes after phagocytosis. We questioned if the peptides were active in destroying endosomal membranes to avoid lysosomal killing of the pathogen and monitored integrity of infected host cell endosomes by measuring the acidity of the intracellular bacterial microenvironment via flow cytometry and by a reporter recruitment technique. Isogenic mutants of the methicillin-resistant S. aureus (MRSA) strains USA300 LAC, USA400 MW2 as well as the strongly cytolytic methicillin-sensitive strain 6850 were compared with their respective wild type strains. In all three genetic backgrounds, PSMα mutants were unable to escape from phagosomes in non-professional (293, HeLa, EAhy.926) and professional phagocytes (THP-1), whereas mutants in PSMβ and δ-toxin as well as β-toxin, phosphatidyl inositol-dependent phospholipase C and Panton Valentine leucotoxin escaped with efficiencies of the parental strains. S. aureus replicated intracellularly only in presence of a functional PSMα operon thereby illustrating that bacteria grow in the host cell cytoplasm upon phagosomal escape. © 2013 John Wiley & Sons Ltd.
Türkyilmaz, S; Tekbiyik, S; Oryasin, E; Bozdogan, B
The aim of this study was to identify methicillin-resistant Staphylococcus aureus (MRSA) strains gathered from 2002 to 2006 from milk samples in Aydin region in Turkey. Among 93 S. aureus strains isolated from bovine milk with mastitis, 16 were resistant to methicillin. Methicillin-resistant S. aureus strains were studied further for their staphylococcal cassette chromosome mec (SCCmec) types, pulsotypes, spa and MLST types, antimicrobial susceptibilities, mechanisms of resistance and presence of Panton-Valentine leucocidin (PVL) toxin gene. The MRSA strains were multi-drug resistant. The susceptibility rates to antimicrobials tested were 0%, 0%, 0%, 0%, 6.25%, 16.25% and 56.25% for erythromycin, clindamycin, chloramphenicol, gentamicin, tetracyclin, ciprofloxacin and vancomycin, respectively. All tetracycline and gentamicin resistant strains carried tet(M) and aac(6)-aph(2) gene, respectively. Among macrolide-resistant isolates, nine had erm(A), and seven had both erm(A) and erm(B) genes. The molecular characterization by pulsed-field gel electrophoresis showed presence of three pulsotypes with their variants. The pulsotype B strains were type IV with SCCmec typing, and representative of pulsotype B was t190 by spa typing and ST8 by MLST typing. The strains with pulsotype A and C were SCCmec III, and representative of these pulsotypes was t030 by spa typing. The MLST type of pulsotype A was ST239 and pulsotype C was one allele variant of ST239. None of the isolates harboured the PVL gene. Presence of hospital-related MRSA strains may indicate transmission of these strains between human and animals. In case of clonal spread beside the infected animals' treatment of MRSA carrier, farm workers should also be considered. Hygienic measures and rational antibiotic use may avoid resistance selection, clonal dissemination of resistant strains and decrease losses because of mastitis in dairy herds.
Full Text Available This study characterized EMRSA-15 isolates obtained from patients in Kuwait hospitals for their genotypic relatedness, antibiotic resistance and carriage of virulence genes using pulsed-field gel electrophoresis (PFGE, coagulase serotyping, SCCmec subtyping, spa typing, multilocus sequence typing and DNA microarray. The isolates were resistant to trimethoprim (75.6%, ciprofloxacin (29.7%, erythromycin and clindamycin (24.3%, tetracycline (19.0%, and gentamicin and kanamycin (21.6%. All 37 isolates belonged to sequence type (ST 22, coagulase type XI, three PFGE types and eight subtypes, ten spa types including t223 (51.3%, t852 (13.5%, t032 (8.1%, t790 (8.1%, t3107 (5.4% and one each of t309, t2251, t3935, t5708 and t5983. Twenty-six isolates (70.2% carried SCCmec IVa, eight isolates carried SCCmec IV and three isolates carried SCCmec IVh. All isolates carried agr1, cap5 and egc gene cluster (seg, sei, selm, seln, selo, and selu. tst (toxic shock syndrome toxin was detected in 23 isolates. Eight isolates (21.6% were positive for Panton-Valentine leukocidin (PVL. Genotypic analysis revealed that 62.1% of the isolates comprising ST22-IVa-t223 (51.3% and ST22-IVa-t309/t2251/t3935/t5708 (10.8% were CC22-[tst1+] UK EMRSA-15/Middle Eastern variant, 21.6% were CC22-PVL+ EMRSA-15 variant and 16.2% were CC22-UK EMRSA-15/Barnim clone. These results show that the tst1 positive-ST22-IVa-t223 (Middle Eastern variant and the CC22-PVL+ EMRSA-15 variant were the dominant EMRSA-15 variants in Kuwait hospitals.
Yamamoto, Tatsuo; Nishiyama, Akihito; Takano, Tomomi; Yabe, Shizuka; Higuchi, Wataru; Razvina, Olga; Shi, Da
Methicillin-resistant Staphylococcus aureus (MRSA) is able to persist not only in hospitals (with a high level of antimicrobial agent use) but also in the community (with a low level of antimicrobial agent use). The former is called hospital-acquired MRSA (HA-MRSA) and the latter community-acquired MRSA (CA-MRSA). It is believed MRSA clones are generated from S. aureus through insertion of the staphylococcal cassette chromosome mec (SCCmec), and outbreaks occur as they spread. Several worldwide and regional clones have been identified, and their epidemiological, clinical, and genetic characteristics have been described. CA-MRSA is likely able to survive in the community because of suitable SCCmec types (type IV or V), a clone-specific colonization/infection nature, toxin profiles (including Pantone-Valentine leucocidin, PVL), and narrow drug resistance patterns. CA-MRSA infections are generally seen in healthy children or young athletes, with unexpected cases of diseases, and also in elderly inpatients, occasionally surprising clinicians used to HA-MRSA infections. CA-MRSA spreads within families and close-contact groups or even through public transport, demonstrating transmission cores. Re-infection (including multifocal infection) frequently occurs, if the cores are not sought out and properly eradicated. Recently, attention has been given to CA-MRSA (USA300), which originated in the US, and is growing as HA-MRSA and also as a worldwide clone. CA-MRSA infection in influenza season has increasingly been noted as well. MRSA is also found in farm and companion animals, and has occasionally transferred to humans. As such, the epidemiological, clinical, and genetic behavior of CA-MRSA, a growing threat, is focused on in this study.
Non-hospital environment contamination with Staphylococcus aureus and methicillin-resistant Staphylococcus aureus: proportion meta-analysis and features of antibiotic resistance and molecular genetics.
Lin, Jialing; Lin, Dongxin; Xu, Ping; Zhang, Ting; Ou, Qianting; Bai, Chan; Yao, Zhenjiang
Staphylococcus aureus (S. aureus), including methicillin-resistant Staphylococcus aureus (MRSA), survives in dry conditions and can persist for long periods on surfaces touched by humans. Studies that estimate the proportions and characteristics of S. aureus and MRSA contamination in non-hospital environments are lacking. Therefore, we conducted a proportion meta-analysis and reviewed the features of antibiotic resistance and molecular genetics. Articles published between January 2005 and December 2015 that studied proportions of S. aureus and MRSA contamination in non-hospital environments were retrieved from the Medline database, Ovid database and Science Direct database. All statistics were analyzed by STATA 14.1. Twenty-nine articles were included. The overall proportions of S. aureus and MRSA contamination were 41.1% (95%CI 29-54%) and 8.6% (95%CI 5-13%), respectively. The proportion of MRSA contamination increased over time. From the articles, the proportion of Panton-Valentine Leukociden (PVL) genes among MRSA isolates was 54.5%, and the proportion of the qac gene was 100.0%. Distribution of the multilocus sequence type (MLST) and pulsed-field gel electrophoresis (PFGE) of MRSA indicated that MRSA strains were from both hospitals and communities. The overall proportions of S. aureus and MRSA contamination in non-hospital environments were high. The outcomes of antibiotic resistance and high proportions of PVL genes indicated that the antibiotic resistance of S. aureus and MRSA were notable. According to the different distributions of MLST and SCCmec of MRSA, we can infer that cross-circulation is within hospitals, communities, and livestock. The results also show that the risk from the MRSA strains was cross-transmitted among the population. High proportions of the qac gene of MRSA might indicate that current disinfection of MRSA has not been achieved, and it might be better to further identify the efficiency of the sterilization processes in a non
Velázquez-Meza, Maria Elena; Mendoza-Olazarán, Soraya; Echániz-Aviles, Gabriela; Camacho-Ortiz, Adrián; Martínez-Reséndez, Michel Fernando; Valero-Moreno, Vanessa; Garza-González, Elvira
Methicillin-resistant Staphylococcus aureus (MRSA) colonizes the skin of hospitalized patients and is associated with high morbidity and mortality. To prevent colonization and infection by S. aureus, better disinfection practices are required. Therefore, we evaluated the effect of chlorhexidine whole-body washing on hospital-acquired S. aureus infections among intensive care unit (ICU) patients in a tertiary hospital in Mexico. The study was conducted over 18 months to evaluate the effect of 2 % chlorhexidine gluconate (CXG) whole-body washing of ICU adult patients on chlorhexidine and antibiotic resistance, biofilm production and clonal distribution of S. aureus in a tertiary care hospital. Minimum inhibitory concentrations for CXG, antibiotic susceptibility and biofilm production by S. aureus isolates were determined. Pulsed-field gel electrophoresis, multilocus sequence typing (MLST) and PCR for Panton-Valentine leucocidin (PVL) were used for molecular typing of MRSA isolates.Results/Key findings. We included 158 isolates. A reduction in antibiotic resistance in the study period was observed for clindamycin, levofloxacin, norfloxacin, oxacillin and trimethoprim/sulfamethoxazole. None of the isolates showed reduced susceptibility to CXG. Most of the isolates were non-biofilm producers (147/158). The most commonly identified clone was a descendant of the ST5-MRSA-II (New York/Japan) clone. This clone decreased during the intervention period and reappeared markedly in the post-intervention period. During the post-intervention period, two isolates were related with the clone ST8-MRSA-IV (also known as USA300). Our findings suggest that the CXG bathing favored the reduction of healthcare-associated MRSA isolates and a temporary reduction of the predominant ST5-MRSA-II (New York/Japan) clone.
Franco, Alessia; Hasman, Henrik; Iurescia, Manuela; Lorenzetti, Raniero; Stegger, Marc; Pantosti, Annalisa; Feltrin, Fabiola; Ianzano, Angela; Porrero, Maria Concepción; Liapi, Maria; Battisti, Antonio
The aim of this study was to provide molecular characterization of methicillin-resistant Staphylococcus aureus (MRSA) spa type t127, sequence type (ST) 1 isolates, detected in a European baseline survey in holdings of breeding pigs, to determine phenotypic and genotypic drug resistance and to compare the results with those obtained from a collection of t127, ST1 MRSA and methicillin-susceptible S. aureus (MSSA) clinical isolates. Twenty-four t127, ST1 MRSA from dust sampled in different breeding holdings in Italy, Spain and Cyprus were studied, along with 2 t127, ST1 MRSA from fattening pigs and 11 human t127, ST1 MRSA and MSSA. Genotyping was performed using multilocus sequence typing (MLST), spa typing and PFGE. SCCmec elements were characterized by multiplex-PCR and resistance and pathogenicity genes by PCR and microarray. PFGE patterns separated a porcine cluster (PC) from a human cluster (HC), with 75% similarity. The PC carried SCCmec cassette type V, while all isolates of the HC carried SCCmec cassette type IVa. Kanamycin resistance mediated by aadD, fluoroquinolone and erm(A)-mediated macrolide resistance and the absence of the sakA gene were features of the PC only. All isolates of both clusters were positive for LukE-LukD and LuF-LukS-HlgA leukotoxin genes and one human MSSA harboured Panton-Valentine leucocidin genes. Despite differences in the host-specific genetic features, the possibility of PC transmission to humans cannot be excluded. MRSA spa type t127, ST1 from pigs possesses several virulence and resistance genes towards major classes of antimicrobials and may represent a serious therapeutic challenge in case of invasive infections in humans.
Full Text Available Staphylococcus aureus is an important food-borne opportunistic pathogen that frequently causes severe blood and tissue infections or even fatal illnesses. Although S. aureus has been extensively studied in livestock and poultry foods in China, limited information has been reported in aquatic products. Accordingly, in this study, we aimed to characterize S. aureus in aquatic products purchased from retail markets in China. In total, 320 aquatic food samples were collected from 32 provincial capitals in China. The results showed that 119 samples (37.2%, 119/320 were positive for S. aureus by both qualitative and quantitative analyses. The contamination levels of 78.2% of samples ranged from 0.3 to 10 MPN/g, and six samples exceeded 110 MPN/g. A total of 119 S. aureus isolates from positive samples were selected to evaluate virulence factors, antibiotic resistance, and molecular characteristics. All S. aureus isolates were evaluated for the presence of 11 virulence genes by multiplex polymerase chain reaction, and α-hemolysin (hlα, 84.9%, fibronectin-binding protein A (fnbA, 79.0%, S. aureus enterotoxin E (see, 53.8%, and Panton-Valentine leucocidin (pvl, 50.4% were identified as the major genes. These genes formed 56 different profiles, with the major profile identified as pvl-hlα-fnbA (28.6%. The antimicrobial susceptibility of all isolates was analyzed through the disk diffusion method, and the results showed high resistance to β-lactams, macrolides and tetracyclines, but susceptibility to linezolid and vancomycin. In addition, 26 sequence types (STs were obtained via multilocus sequence typing, including seven novel STs, among which ST1 (20.2%, ST15 (18.5%, and ST188 (13.4% were the most common STs. All the isolates were mecC negative, but nine isolates carrying mecA were evaluated by staphylococcal cassette chromosome mec (SCCmec typing, all of which were SCCmecIII or SCCmecIV types. Isolates of SCCmecIII showed a high prevalence and were
Rump, B.; Kessler, C.; Fanoy, Ewout; Wassenberg, Marjan; Krom, André; Verweij, M.F.; Steenbergen, van Jim
A Dutch medical student has the potentially more virulent Panton-Valentine leukocidin (PVL) form of MRSA colonization yet shows no signs or symptoms of infection. More than a year ago, a routine MRSA screening of health care personnel providing care for MRSA-positive patients detected the
Ana María Perilla
Ambos desarrollaron falla renal aguda, por lo que fueron manejados con linezolide, con adecuada respuesta clínica. Con la caracterización molecular de los aislamientos se confirmó la presencia del gen mecA que porta el casete SCCmec tipo IV y la producción de la toxina leucocidina Panton-Valentine.
Hammad, Ahmed M; Watanabe, Wataru; Fujii, Tomoko; Shimamoto, Tadashi
the S. aureus isolates carried the Panton-Valentine leucocidin (PVL) encoding genes, lukF-PV and lukS-PV. To the best of our knowledge, this is the first report to show MRSA and MR-CoNS isolated from retail ready-to-eat food in Japan. Our results showed that sashimi is a likely vehicle for transmission of multidrug-resistant and toxigenic staphylococci. Copyright © 2012 Elsevier B.V. All rights reserved.
Mostafa FN Abushahba
Full Text Available Staphylococcus aureus infections present a serious challenge to healthcare practitioners due to the emergence of resistance to numerous conventional antibiotics. Due to their unique mode of action, peptide nucleic acids are novel alternatives to traditional antibiotics to tackle the issue of bacterial multidrug resistance. In this study, we designed a peptide nucleic acid covalently conjugated to the HIV-TAT cell penetrating peptide (GRKKKRRQRRRYK in order to target the RNA polymerase α subunit gene (rpoA required for bacterial genes transcription. We explored the antimicrobial activity of the anti-rpoA construct (peptide nucleic acid-TAT against methicillin-resistant S. aureus, vancomycin-intermediate S. aureus, vancomycin-resistant S. aureus, linezolid-resistant S. aureus, and methicillin-resistant S. epidermidis in pure culture, infected mammalian cell culture, and in an in vivo Caenorhabditis elegans infection model. The anti-rpoA construct led to a concentration-dependent inhibition of bacterial growth (at micromolar concentrations in vitro and in both infected cell culture and in vivo in C. elegans. Moreover, rpoA gene silencing resulted in suppression of its message as well as reduced expression of two important methicillin-resistant S. aureus USA300 toxins (α-hemolysin and Panton-Valentine leukocidin. This study confirms that rpoA gene is a potential target for development of novel antisense therapeutics to treat infections caused by methicillin-resistant S. aureus.
Prevalence and molecular characteristics of Staphylococcus aureus, including methicillin resistant strains, isolated from bulk can milk and raw milk products in pastoral communities of South-West Uganda.
Asiimwe, Benon B; Baldan, Rossella; Trovato, Alberto; Cirillo, Daniela M
Staphylococcus aureus strains are now regarded as zoonotic agents. In pastoral settings where human-animal interaction is intimate, multi-drug resistant microorganisms have become an emerging zoonotic issue of public health concern. The study of S. aureus prevalence, antimicrobial resistance and clonal lineages in humans, animals and food in African settings has great relevance, taking into consideration the high diversity of ethnicities, cultures and food habits that determine the lifestyle of the people. Little is known about milk carriage of methicillin resistant S. aureus strains (MRSA) and their virulence factors in Uganda. Here, we present the prevalence of MRSA in bulk can milk and raw milk products in pastoral communities of south-west Uganda. We also present PFGE profiles, spa-types, as well as frequency of enterotoxins genes. S. aureus was identified by the coagulase test, susceptibility testing by the Kirby-Bauer disc diffusion and E-test methods and MRSA by detection of the mecA gene and SCCmec types. The presence of Panton - Valentine Leucocidin (PVL) genes and staphylococcal enterotoxins was determined by PCR, while genotyping was by PFGE and spa typing. S. aureus were isolated from 30/148 (20.3%) milk and 11/91(12%) sour milk samples. mecA gene carriage, hence MRSA, was detected in 23/41 (56.1%) of the isolates, with 21 of the 23 (91.3%) being SCCmec type V; while up to 30/41 (73.2%) of the isolates were resistant to tetracycline. Only five isolates carried the PVL virulence gene, while PFGE typing revealed ten clusters (ranging from two seven isolates each) that comprised 83% of the sample, and only eight isolates with unique pulsotypes. The largest PFGE profile (E) consisted of seven isolates while t7753, t1398, and t2112 were the most common spa-types. Thirty seven of the 41 strains (90.2%) showed at least one of the eight enterotoxin genes tested, with sem 29 (70.7%), sei 25 (61%) and seg 21 (51.2%) being the most frequently observed genes. This
Abstract. Panton-Valentine leucocidin (PVL), a synergohymentropic toxins encoded on S.aureus genes are associated with soft tissue infection and community-acquired staphylococcal infection. The purpose of the study was to determine the prevalence and antibiotic susceptibility of PVL- postive S.aureus isolates from ...
Aline Peçanha Muzy Dias
Full Text Available S. aureus está presente em cerca de 30% dos humanos de maneira assintomática e os sítios de maior prevalência são as fossas nasais, axilas e períneo.Este microrganismo pode causar diversos processos patológicos desde os mais simples como furúnculo e acne até mais os mais complexos como pneumonias, meningite, síndrome de choque tóxico, endocardites, infecções no trato urinário, infecções associadas com dispositivos intravasculares e corpos estranhos e sepse. Diversos estudos têm sido realizados a fim de aprimorar o entendimento dos mecanismos de transmissão e controle da disseminação deste patógeno, descrevendo as cepas encontradas em diferentes ambientes. Dentre os diversos fatores de virulência responsáveis pelas infecções, destacam-se a α-hemolisina, β-toxina, PSM-α, proteína A e a leucocidina Panton-Valentine, demonstrando um importante papel na patogênese por S. aureus. O uso racional de antimicrobianos para MRSA deve ser feito sabendo-se a terapia correta para o tratamento desta infecção de grande importância na comunidade científica. Uma rápida avaliação da etiologia da infecção é também relevante para a aplicação do tratamento adequado, pois nos casos de MRSA é fundamental no tratamento empírico, não começar somente com antibióticos betalactâmicos. Cada vez mais, os governos de todo o mundo estão começando a prestar atenção a um problema tão grave que ameaça as conquistas da medicina moderna. A era pós-antibiótico, em que infecções comuns e lesões menores podem matar, longe de ser uma fantasia, pode se tornar uma possibilidade muito real para o século 21.
Harris, Simon R; Cartwright, Edward J P; Török, M Estée; Holden, Matthew T G; Brown, Nicholas M; Ogilvy-Stuart, Amanda L; Ellington, Matthew J; Quail, Michael A; Bentley, Stephen D; Parkhill, Julian; Peacock, Sharon J
The emergence of meticillin-resistant Staphylococcus aureus (MRSA) that can persist in the community and replace existing hospital-adapted lineages of MRSA means that it is necessary to understand transmission dynamics in terms of hospitals and the community as one entity. We assessed the use of whole-genome sequencing to enhance detection of MRSA transmission between these settings. We studied a putative MRSA outbreak on a special care baby unit (SCBU) at a National Health Service Foundation Trust in Cambridge, UK. We used whole-genome sequencing to validate and expand findings from an infection-control team who assessed the outbreak through conventional analysis of epidemiological data and antibiogram profiles. We sequenced isolates from all colonised patients in the SCBU, and sequenced MRSA isolates from patients in the hospital or community with the same antibiotic susceptibility profile as the outbreak strain. The hospital infection-control team identified 12 infants colonised with MRSA in a 6 month period in 2011, who were suspected of being linked, but a persistent outbreak could not be confirmed with conventional methods. With whole-genome sequencing, we identified 26 related cases of MRSA carriage, and showed transmission occurred within the SCBU, between mothers on a postnatal ward, and in the community. The outbreak MRSA type was a new sequence type (ST) 2371, which is closely related to ST22, but contains genes encoding Panton-Valentine leucocidin. Whole-genome sequencing data were used to propose and confirm that MRSA carriage by a staff member had allowed the outbreak to persist during periods without known infection on the SCBU and after a deep clean. Whole-genome sequencing holds great promise for rapid, accurate, and comprehensive identification of bacterial transmission pathways in hospital and community settings, with concomitant reductions in infections, morbidity, and costs. UK Clinical Research Collaboration Translational Infection Research
Fatima Rodríguez Acosta
Full Text Available Staphylococcus aureus es un microorganismo con habilidad de infectar diferentes tejidos celulares, por portar genes que le confieren resistencia a antibióticos, factores de virulencia y su plasticidad genética, que podrían contribuir a una progresión rápida y complicada de la enfermedad. El Paraguay no cuenta con datos epidemiológicos que indiquen los factores de virulencia que presentan las cepas de S. aureus, por lo que el objetivo del trabajo fue determinar un perfil de virulencia detectando los genes codificantes de: hemolisinas α y β, enterotoxinas A, B, C, D, H y toxinas exfoliativas A y B. Este estudio observacional descriptivo de corte transverso, con muestreo no probabilístico de casos consecutivos, incluyó 50 aislados de S. aureus obtenidos a partir de muestras clínicas de secreciones de piel, partes blandas o líquidos corporales de pacientes menores de 17 años que concurrieron al Hospital General Pediátrico Niños de Acosta Ñú durante el año 2.010. Las reacciones de PCR incluyeron la detección de los genes: sea+seb+sec+ADNr16S, hlA+hlB, eta+etb, sed y seh. El 82% de los aislados provenía de niños que presentaron cuadros clínicos compatibles con infecciones de piel y partes blandas y el 18% de cuadros clínicos graves como sepsis, osteomielitis y neumonías. Los aislados contaban con datos de portación de Leucocidina de Panton-Valentine, el cual fue el factor de virulencia más frecuentemente detectado (58%, seguido de las hemolisinas alfa (16% y beta (8%. Las enterotoxinas y las toxinas exfoliativas fueron menos frecuentes (0-2%, y no se detectaron genes codificantes de las enterotoxinas C y D.
Staphylococcus aureus is a leading cause of bacterial infections in humans worldwide. A key host defense strategy against S. aureus is phagocyte-mediated killing. In return, a major mechanism deployed by S. aureus to target host phagocytes is the production of cytolytic toxins. Staphylococcal
Chiappini, Elena; Camposampiero, Caterina; Lazzeri, Simone; Indolfi, Giuseppe; De Martino, Maurizio; Galli, Luisa
Background: Paediatric acute hematogenous osteomyelitis (AHOM) is a serious disease requiring early diagnosis and treatment. To review the clinical presentation, management and organisms responsible for AHOM, and to explore risk factors for complicated AHOM, a large cohort referring to a single center over a 6-year period was evaluated. Methods: Data from children with AHOM, hospitalized between 2010 and 2015, and aged > 1 month, were retrospectively collected and analyzed. Results: 121 children (median age 4.8 years; 55.4% males) were included. Fever at onset was present in 55/121 children (45.5%); the lower limb was most frequently affected (n = 68/121; 56.2%). Microbiological diagnosis (by culture and/or polymerase chain reaction (PCR)) was reached in 33.3% cases. Blood and pus/biopsy culture sensitivities were 32.4% and 46.4%, respectively. PCR sensitivity was 3.6% (2/55) on blood, and 66.6% (16/24) on pus/biopsy sample. Staphylococcus aureus was the most commonly identified pathogen (n = 20); no methicillin-resistant Staphylococcus aureus (MRSA) was isolated, 10.0% (n = 2) strains were Panton-Valentine-Leukocidin (PVL) producer; 48.8% (59/121) cases were complicated. At univariate analysis, factors associated with complicated AHOM were: recent fever episode, fever at onset, upper limb involvement, white blood count (WBC) ≥ 12,000/µL, C reactive protein (CRP) ≥ 10 mg/L, S. aureus infection. At multivariate analyses S. aureus infection remained the only risk factor for complicated AHOM (aOR = 3.388 (95%CI: 1.061-10.824); p-value = 0.039). Conclusions: In this study microbiological diagnosis was obtained in over one third of cases. Empiric treatment targeting methicillin-sensitive Staphylococcus aureus seems to be justified by available microbiological data.
Aragüés, M; González-Arriba, A
Pyodermitis constitutes a very important chapter in dermatological practice. Its pathogenesis, in special the one caused by S. aureus, has improved due to the knowledge of the role developed by the host defensins, quorum-sensing signaling and the Panton-Valentine leucocidin gene among others. As well, exfoliative toxins and enterotoxins responsible for the staphylococal scalded skin syndrome (SSSS) and toxic shock syndrome, respectively, have been cloned. Also, it has been seen that bullous impetigo, SSSS and pemphigus foliaceus share a common target: desmoglein-1. The Panton-Valentine leucocidin gene has been related to the appearance of abscesses, necrotic cutaneous lesions and furuncles in young persons caused by meticillin resistant S. aureus, with its epidemiological implications. Finally, some atypical forms of erysipelas suppose a diagnostic challenge for the dermatologist.
Sofanne J Ravensbergen
Full Text Available Migration is one of the risk factors for the spread of multidrug-resistant organisms (MDRO. The increasing influx of migrants challenges local health care systems. To provide evidence for both hospital hygiene measure and empirical antibiotic therapy, we analysed all cultures performed in asylum seekers between January 1st 2014 and December 31st 2015 for methicillin resistant Staphylococcus aureus (MRSA and for multidrug-resistant Enterobacteriaceae (MDRE. We compared these with cultures from the Dutch patient population with risk factors for carriage of MDRO. A total of 7181 patients were screened for MRSA. 7357 S. aureus were isolated in clinical cultures. Of 898 screened asylum seekers, almost 10% were MRSA positive. Of 118 asylum seekers with S. aureus in clinical cultures almost 19% were MRSA positive. The general patient population had a 1.3% rate of MRSA in S. aureus isolates. A higher rate of Panton-Valentine leukocidin (PVL positive strains (RR: 2.4; 95% CI: 1.6-3.4 was found in asylum seekers compared to the general patient population. In 33475 patients one or more Enterobacteriaceae were obtained. More than 21% of the asylum seekers were carrier of MDRE, most of them producing extended spectrum beta-lactamases (20.3%. 5.1% of the general patient population was MDRE carrier. It can be concluded that asylum seekers present with higher rate of MDRO compared to the general patient population. These results justify continued screening of asylum seekers to anticipate multidrug-resistant organisms during hospital care of patients.
Ravensbergen, Sofanne J; Berends, Matthijs; Stienstra, Ymkje; Ott, Alewijn
Migration is one of the risk factors for the spread of multidrug-resistant organisms (MDRO). The increasing influx of migrants challenges local health care systems. To provide evidence for both hospital hygiene measure and empirical antibiotic therapy, we analysed all cultures performed in asylum seekers between January 1st 2014 and December 31st 2015 for methicillin resistant Staphylococcus aureus (MRSA) and for multidrug-resistant Enterobacteriaceae (MDRE). We compared these with cultures from the Dutch patient population with risk factors for carriage of MDRO. A total of 7181 patients were screened for MRSA. 7357 S. aureus were isolated in clinical cultures. Of 898 screened asylum seekers, almost 10% were MRSA positive. Of 118 asylum seekers with S. aureus in clinical cultures almost 19% were MRSA positive. The general patient population had a 1.3% rate of MRSA in S. aureus isolates. A higher rate of Panton-Valentine leukocidin (PVL) positive strains (RR: 2.4; 95% CI: 1.6-3.4) was found in asylum seekers compared to the general patient population. In 33475 patients one or more Enterobacteriaceae were obtained. More than 21% of the asylum seekers were carrier of MDRE, most of them producing extended spectrum beta-lactamases (20.3%). 5.1% of the general patient population was MDRE carrier. It can be concluded that asylum seekers present with higher rate of MDRO compared to the general patient population. These results justify continued screening of asylum seekers to anticipate multidrug-resistant organisms during hospital care of patients.
Hardgrib, Nina; Wang, Michala; Jurik, Anne Grethe
The incidence and severity of methicillin resistant Staphylococcus aureus (MRSA) infections are increasing and cause high mortality and morbidity. We describe the first pediatric case in Scandinavia with Panton-Valentine leucocidin (PVL) positive MRSA septicemia who developed bilateral pneumonia...... and antimicrobial combination therapy. The outcome was a healthy patient without sequelae, a favorable course unlike those previously described in the literature. This case underlines the necessity of a close interdisciplinary cooperation in children with severe MRSA infection encompassing pneumonia, septic...
Wedley, Amy L; Dawson, Susan; Maddox, Thomas W; Coyne, Karen P; Pinchbeck, Gina L; Clegg, Peter; Jamrozy, Dorota; Fielder, Mark D; Donovan, David; Nuttall, Tim; Williams, Nicola J
This study investigated the prevalence of nasal carriage of staphylococci in dogs and determined the characteristics of the isolates. A total of 724 dogs from 87 veterinary practices across the mainland UK were screened for carriage of Staphylococcus spp. All isolates were examined for meticillin resistance (MR) and the presence of the mecA gene investigated in those isolates showing resistance. All coagulase-positive staphylococci and MR coagulase-negative staphylococci (MRCoNS) were subjected to antimicrobial susceptibility testing. Spa typing and DNA microarray analysis of resistance and virulence genes was carried out on all MR S. aureus (MRSA) and a subset of meticillin susceptible S. aureus (MSSA). Staphylococci were isolated from 399 (55.1%) of the dogs; only seven (1%) carried MRSA, all of which were identified as the dominant UK healthcare-associated strain (EMRSA-15, ST22). MSSA was identified in 47 (6.5%) dogs, the sequence types of which have been suggested as precursors to successful MRSA clones. Forty (5.5%) dogs carried MRCoNS, while no dogs carried MR S. pseudintermedius, although this is increasingly reported in mainland Europe. Resistance to antimicrobials among the isolates varied between species, with multidrug resistance (MDR) in 87.5% of MRCoNS and 21.8% of coagulase positive staphylococci. Microarray analysis of MRSA and a subset of MSSA isolates identified numerous virulence genes associated with pathogenesis, which are commonly identified in isolates of human origin. However, no isolates carried Panton-Valentine leukocidin (PVL) genes. This study suggests that MRSA carriage is low in the vet visiting dog population, but there is a diverse range of virulence and resistance determinants in canine S. aureus and MRCoNS isolates. Copyright © 2014 Elsevier B.V. All rights reserved.
Lin, J L; Peng, Y; Ou, Q T; Lin, D X; Li, Y; Ye, X H; Zhou, J L; Yao, Z J
Methicillin-resistant Staphylococcus aureus (MRSA) has caused a series of public health problems since it was first found in 1961. However, there are few research studies on the MRSA environmental contamination in railway stations and coach stations. Therefore, the aim of this study was to determine MRSA environmental contamination in public transport stations. Between December 2013 and January 2014, 380 surface samples from three railway stations (180) and four coach stations (200) in Guangzhou were collected to isolate and determine the prevalence and characteristics of Staphylococci strains. 39·21% of all samples were Staphylococci isolates, 1·58% of Staphylococci isolates were MRSA isolates, and 6·05% were methicillin-susceptible S. aureus. The proportion of multidrug resistant among 149 Staphylococci isolates was 75·84%. None of MRSA isolates was identified with the Panton-Valentine Leukocidin (PVL) genes, and one of them was identified with the qac gene. Four MRSA isolates were Staphylococcal Cassette Chromosome mec IVa, and the other two were nontypeable. Staphylococcus aureus isolates were classified into several sequence types (STs), and STs showed possible cross-transmissions of isolates from various sources. Methicillin-resistant Staphylococci contamination prevalence was high, and the environment of stations may be the vectors transmitting the Staphylococci to passengers. This is the first study to comprehensively report the prevalence, antibiotic resistance, and molecular characteristics of contamination of Staphylococci isolates in railway stations and coach stations of China. It will have great public health implications on infection control in community settings because of the serious hazard of Staphylococci, especially methicillin-resistant Staphylococci. Our findings have provided evidence for relevant departments to reduce the contamination of Staphylococci in environment of public transport stations. © 2016 The Society for Applied
Full Text Available Staphylococcus aureus is a major human pathogen that elaborates several exotoxins. Among these are the bicomponent leukotoxins (BCLs, which include γ-hemolysin, Panton-Valentine leukocidin (PVL, and LukDE. The toxin components are classified as either F or S proteins, which are secreted individually and assemble on cell surfaces to form hetero-oligomeric pores resulting in lysis of PMNs and/or erythrocytes. F and S proteins of γ-hemolysin, PVL and LukDE have ∼ 70% sequence homology within the same class and several heterologous combinations of F and S members from these three bicomponent toxin groups are functional. Recently, an additional BCL pair, LukGH (also called LukAB that has only 30% homology to γ-hemolysin, PVL and LukDE, has been characterized from S. aureus. Our results showed that LukGH was more cytotoxic to human PMNs than PVL. However, LukGH-induced calcium ion influx in PMNs was markedly attenuated and slower than that induced by PVL and other staphylococcal BCLs. In contrast to other heterologous BCL combinations, LukG in combination with heterologous S components, and LukH in combination with heterologous F components did not induce calcium ion entry or cell lysis in human PMNs or rabbit erythrocytes. Like PVL, LukGH induced IL-8 production by PMNs. While individual components LukG and LukH had no cytolytic or calcium influx activity, they each induced high levels of IL-8 transcription and secretion. IL-8 production induced by LukG or LukH was dependent on NF-κB. Therefore, our results indicate LukGH differs functionally from other staphylococcal BCLs.
Full Text Available In a clinical infection, multiplying and non-multiplying bacteria co-exist. Antibiotics kill multiplying bacteria, but they are very inefficient at killing non-multipliers which leads to slow or partial death of the total target population of microbes in an infected tissue. This prolongs the duration of therapy, increases the emergence of resistance and so contributes to the short life span of antibiotics after they reach the market. Targeting non-multiplying bacteria from the onset of an antibiotic development program is a new concept. This paper describes the proof of principle for this concept, which has resulted in the development of the first antibiotic using this approach. The antibiotic, called HT61, is a small quinolone-derived compound with a molecular mass of about 400 Daltons, and is active against non-multiplying bacteria, including methicillin sensitive and resistant, as well as Panton-Valentine leukocidin-carrying Staphylococcus aureus. It also kills mupirocin resistant MRSA. The mechanism of action of the drug is depolarisation of the cell membrane and destruction of the cell wall. The speed of kill is within two hours. In comparison to the conventional antibiotics, HT61 kills non-multiplying cells more effectively, 6 logs versus less than one log for major marketed antibiotics. HT61 kills methicillin sensitive and resistant S. aureus in the murine skin bacterial colonization and infection models. No resistant phenotype was produced during 50 serial cultures over a one year period. The antibiotic caused no adverse affects after application to the skin of minipigs. Targeting non-multiplying bacteria using this method should be able to yield many new classes of antibiotic. These antibiotics may be able to reduce the rate of emergence of resistance, shorten the duration of therapy, and reduce relapse rates.
Brennan, Gráinne I
Sequence type 22 (ST22) methicillin-resistant Staphylococcus aureus (MRSA) harboring staphylococcal cassette chromosome mec (SCCmec) IV (ST22-MRSA-IV) has predominated in Irish hospitals since the late 1990s. Six distinct clones of community-associated MRSA (CA-MRSA) have also been identified in Ireland. A new strain of CA-MRSA, ST772-MRSA-V, has recently emerged and become widespread in India and has spread into hospitals. In the present study, highly similar MRSA isolates were recovered from seven colonized neonates in a neonatal intensive care unit (NICU) in a maternity hospital in Ireland during 2010 and 2011, two colonized NICU staff, one of their colonized children, and a NICU environmental site. The isolates exhibited multiantibiotic resistance, spa type t657, and were assigned to ST772-MRSA-V by DNA microarray profiling. All isolates encoded resistance to macrolides [msr(A) and mpb(BM)] and aminoglycosides (aacA-aphD and aphA3) and harbored the Panton-Valentine leukocidin toxin genes (lukF-PV and lukS-PV), enterotoxin genes (sea, sec, sel, and egc), and one of the immune evasion complex genes (scn). One of the NICU staff colonized by ST772-MRSA-V was identified as the probable index case, based on recent travel to India. Seven additional hospital and CA-ST772-MRSA-V isolates recovered from skin and soft tissue infections in Ireland between 2009 and 2011 exhibiting highly similar phenotypic and genotypic characteristics to the NICU isolates were also identified. The clinical details of four of these patients revealed connections with India through ethnic background or travel. Our study indicates that hospital-acquired and CA-ST772-MRSA-V is currently emerging in Ireland and may have been imported from India on several occasions.
Sciauvaud, J; Rigal, E; Pascal, J; Nourrisson, C; Poirier, P; Poirier, V; Vidal, M; Mrozek, N; Laurichesse, H; Beytout, J; Labbe, A; Lesens, O
Internationally adopted children may suffer from different pathologies, including infectious diseases contracted in the country of origin. We evaluated the frequency of infectious diseases that may disseminate from adoptees to adoptive families on their arrival in France. All children who attended the clinic for international adoption in Clermont-Ferrand from January 2009 through to December 2011 were eligible for inclusion in the study. Standardized medical records dedicated to international adoption were retrospectively reviewed for demographic data, clinical diagnosis, and biological and radiological results. Data were completed by phone interviews with adoptive families after informed consent. One hundred and forty-two medical records were retrospectively reviewed and 86% of families agreed to be interviewed. One hundred and seventy-one potentially transmissible infections were diagnosed in 142 children, 12% (n = 20) of which were transmitted to adoptive families. Most of these infections were benign and transmission was restricted to the close family. Tinea was diagnosed in 44 adoptees and transmitted in 15 cases. Panton Valentine leukocidin producing methicillin-sensitive S. aureus (MSSA) was transmitted to an adoptive father who required hospitalization for bursitis. Transmission also occurred for CMV (n = 1), hepatitis A (n = 1), giardiasis (n = 1), scabies (n = 1), Moluscum (n = 2) and pediculosis (n = 2). Two cases of chronic hepatitis B and latent tuberculosis were diagnosed without subsequent transmission. In conclusion, infectious diseases are common in internationally adopted children and should be detected shortly after arrival to avoid transmission. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.
Full Text Available Abstract Background The staphylococci are implicated in a variety of human infections; however, many clinical microbiology laboratories in Nigeria do not identify staphylococci (in particular coagulase negative staphylococci - CNS to the species level. Moreover, data from multi-centre assessment on antibiotic resistance and epidemiology of the staphylococci are not available in Nigeria. This study investigated 91 non-duplicate staphylococcal isolates obtained from the microbiology laboratories of eight hospitals in Nigeria during the period January to April 2010. Methods Identification and antibiotic susceptibility testing was performed using the VITEK 2 system, detection of resistance genes by PCR, and molecular characterization was determined by SCCmec typing, spa and multilocus sequence typing (MLST. Results All the isolates were susceptible to mupirocin, tigecycline, vancomycin and linezolid, but 72.5% of CNS and 82.3% of Staphylococcus aureus were resistant to cotrimoxazole, while multiresistance was observed in 37 of the 40 CNS isolates. Untypeable SCCmec types (ccrC/Class A mec and ccr-negative/Class C2 mec gene complex in two methicillin-resistant S. aureus (MRSA were identified. Additionally, ccr-negative/Class A mec and ccr type 4/Class C2 mec gene complex was detected in one isolate each of S. sciuri and S. haemolyticus, respectively. The S. aureus isolates were classified into 21 spa types including two new types (t8987, t9008 among the methicillin-susceptible S. aureus (MSSA isolates. Two (CC8-SCCmecnon-typeable and CC88-SCCmec IV and four (CC8-SCCmec III/IV/V; CC30-SCCmec II/III; CC88-SCCmec IV; and ST152-SCCmecnon-typeable MRSA clones were identified in Maiduguri (North-East Nigeria and South-West Nigeria, respectively. The proportion of Panton-Valentine leukocidin (PVL-positive MSSA was high (44.4% and 56.3% of these strains were associated with sequence type (ST 152. Conclusions The identification of multiresistant mecA positive
Fyfe, Corey; O’Brien, William; Hackel, Meredith; Minyard, Mary Beth; Waites, Ken B.; Dubois, Jacques; Murphy, Timothy M.; Slee, Andrew M.; Weiss, William J.; Sutcliffe, Joyce A.
ABSTRACT TP-271 is a novel, fully synthetic fluorocycline antibiotic in clinical development for the treatment of respiratory infections caused by susceptible and multidrug-resistant pathogens. TP-271 was active in MIC assays against key community respiratory Gram-positive and Gram-negative pathogens, including Streptococcus pneumoniae (MIC90 = 0.03 µg/ml), methicillin-sensitive Staphylococcus aureus (MSSA; MIC90 = 0.25 µg/ml), methicillin-resistant S. aureus (MRSA; MIC90 = 0.12 µg/ml), Streptococcus pyogenes (MIC90 = 0.03 µg/ml), Haemophilus influenzae (MIC90 = 0.12 µg/ml), and Moraxella catarrhalis (MIC90 ≤0.016 µg/ml). TP-271 showed activity (MIC90 = 0.12 µg/ml) against community-acquired MRSA expressing Panton-Valentine leukocidin (PVL). MIC90 values against Mycoplasma pneumoniae, Legionella pneumophila, and Chlamydia pneumoniae were 0.004, 1, and 4 µg/ml, respectively. TP-271 was efficacious in neutropenic and immunocompetent animal pneumonia models, generally showing, compared to the burden at the start of dosing, ~2 to 5 log10 CFU reductions against MRSA, S. pneumoniae, and H. influenzae infections when given intravenously (i.v.) and ~1 to 4 log10 CFU reductions when given orally (p.o.). TP-271 was potent against key community-acquired bacterial pneumonia (CABP) pathogens and was minimally affected, or unaffected, by tetracycline-specific resistance mechanisms and fluoroquinolone or macrolide drug resistance phenotypes. IMPORTANCE Rising resistance rates for macrolides, fluoroquinolones, and β-lactams in the most common pathogens associated with community-acquired bacterial pneumonia (CABP) are of concern, especially for cases of moderate to severe infections in vulnerable populations such as the very young and the elderly. New antibiotics that are active against multidrug-resistant Streptococcus pneumoniae and Staphylococcus aureus are needed for use in the empirical treatment of the most severe forms of this disease. TP-271 is a promising
Mairpady Shambat, Srikanth; Chen, Puran; Nguyen Hoang, Anh Thu; Bergsten, Helena; Vandenesch, Francois; Siemens, Nikolai; Lina, Gerard; Monk, Ian R; Foster, Timothy J; Arakere, Gayathri; Svensson, Mattias; Norrby-Teglund, Anna
Staphylococcus aureus necrotizing pneumonia is recognized as a toxin-mediated disease, yet the tissue-destructive events remain elusive, partly as a result of lack of mechanistic studies in human lung tissue. In this study, a three-dimensional (3D) tissue model composed of human lung epithelial cells and fibroblasts was used to delineate the role of specific staphylococcal exotoxins in tissue pathology associated with severe pneumonia. To this end, the models were exposed to the mixture of exotoxins produced by S. aureus strains isolated from patients with varying severity of lung infection, namely necrotizing pneumonia or lung empyema, or to purified toxins. The necrotizing pneumonia strains secreted high levels of α-toxin and Panton-Valentine leukocidin (PVL), and triggered high cytotoxicity, inflammation, necrosis and loss of E-cadherin from the lung epithelium. In contrast, the lung empyema strain produced moderate levels of PVL, but negligible amounts of α-toxin, and triggered limited tissue damage. α-toxin had a direct damaging effect on the epithelium, as verified using toxin-deficient mutants and pure α-toxin. Moreover, PVL contributed to pathology through the lysis of neutrophils. A combination of α-toxin and PVL resulted in the most severe epithelial injury. In addition, toxin-induced release of pro-inflammatory mediators from lung tissue models resulted in enhanced neutrophil migration. Using a collection of 31 strains from patients with staphylococcal pneumonia revealed that strains producing high levels of α-toxin and PVL were cytotoxic and associated with fatal outcome. Also, the strains that produced the highest toxin levels induced significantly greater epithelial disruption. Of importance, toxin-mediated lung epithelium destruction could be inhibited by polyspecific intravenous immunoglobulin containing antibodies against α-toxin and PVL. This study introduces a novel model system for study of staphylococcal pneumonia in a human setting. The
Srikanth Mairpady Shambat
Full Text Available Staphylococcus aureus necrotizing pneumonia is recognized as a toxin-mediated disease, yet the tissue-destructive events remain elusive, partly as a result of lack of mechanistic studies in human lung tissue. In this study, a three-dimensional (3D tissue model composed of human lung epithelial cells and fibroblasts was used to delineate the role of specific staphylococcal exotoxins in tissue pathology associated with severe pneumonia. To this end, the models were exposed to the mixture of exotoxins produced by S. aureus strains isolated from patients with varying severity of lung infection, namely necrotizing pneumonia or lung empyema, or to purified toxins. The necrotizing pneumonia strains secreted high levels of α-toxin and Panton-Valentine leukocidin (PVL, and triggered high cytotoxicity, inflammation, necrosis and loss of E-cadherin from the lung epithelium. In contrast, the lung empyema strain produced moderate levels of PVL, but negligible amounts of α-toxin, and triggered limited tissue damage. α-toxin had a direct damaging effect on the epithelium, as verified using toxin-deficient mutants and pure α-toxin. Moreover, PVL contributed to pathology through the lysis of neutrophils. A combination of α-toxin and PVL resulted in the most severe epithelial injury. In addition, toxin-induced release of pro-inflammatory mediators from lung tissue models resulted in enhanced neutrophil migration. Using a collection of 31 strains from patients with staphylococcal pneumonia revealed that strains producing high levels of α-toxin and PVL were cytotoxic and associated with fatal outcome. Also, the strains that produced the highest toxin levels induced significantly greater epithelial disruption. Of importance, toxin-mediated lung epithelium destruction could be inhibited by polyspecific intravenous immunoglobulin containing antibodies against α-toxin and PVL. This study introduces a novel model system for study of staphylococcal pneumonia in a
Full Text Available In bone and joint infections (BJIs, bacterial toxins are major virulence factors: Panton-Valentine leukocidin (PVL expression leads to severe local damage, including bone distortion and abscesses, while α-hemolysin (Hla production is associated with severe sepsis-related mortality. Recently, other toxins, namely phenol-soluble modulins (PSMs expressed by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA strain USA300 (LAC WT were shown to have ex vivo intracellular cytotoxic activity after S. aureus invasion of osteoblasts, but their in vivo contribution in a relatively PVL-sensitive osteomyelitis model remains poorly elucidated.We compared the outcomes of experimental rabbit osteomyelitises induced with pvl+hla+psms+ LAC WT and its isogenic Δpsm derivatives (LAC Δpsmα and LAC Δpsmαβhld using an inoculum of 3 × 108 CFUs. Mortality, hematogenous spread (blood culture, spleen and kidney, lung and bone involvements were assessed in two groups (non-survivors of severe sepsis and survivors sacrificed on day (D 14.Severe sepsis-related mortality tended to be lower for Δpsm derivatives (Kaplan-Meier curves, P = .06. Non-survivors' bone LAC-Δpsmα (6.9 log10 CFUs/g of bone, P = .04 or -Δpsmαβhld (6.86 log10 CFUs/g of bone, P = .014 densities were significantly higher than LAC WT (6.43 log10 CFUs/g of bone. Conversely, lung Δpsmαβhld CFUs were significantly lower than LAC WT (P = .04. LAC Δpsmα, Δpsmαβhld and WT induced similar bone damage in D14 survivors, with comparable bacterial densities (respectively: 5.89, 5.91, and 6.15 log10 CFUs/g of bone. Meanwhile, pulmonary histological scores of inflammation were significantly higher for LAC Δpsmα- and Δpsmαβhld-infected rabbits compared to LAC WT (P = .04 and .01, respectively but with comparable lung bacterial densities.Our experimental results showed that deactivating PSM peptides significantly limited bacterial dissemination from bone during the early
Full Text Available The spread of toxinogenic Staphylococcus aureus is a public health problem in Africa. The objectives of the study were to investigate the rate of S. aureus nasal carriage and molecular characteristics of these strains in livestock and humans in three Algerian provinces. Nasal samples were collected from camels, horses, cattle, sheep and monkeys, as well as humans in contact with them. S. aureus isolates were genotyped using DNA microarray. The rate of S. aureus nasal carriage varied between species: camels (53%, humans and monkeys (50%, sheep (44.2%, horses (15.2% and cattle (15%. Nine methicillin-resistant S. aureus (MRSA isolates (7.6% were identified, isolated from camels and sheep. The S. aureus isolates belonged to 15 different clonal complexes. Among them, PVL+ (Panton–Valentine Leukocidin isolates belonging to ST80-MRSA-IV and ST152-MSSA were identified in camels (n = 3, 13% and sheep (n = 4, 21.1%. A high prevalence of toxinogenic animal strains was noted containing TSST-1- (22.2%, EDINB- (29.6% and EtD- (11.1% encoding genes. This study showed the dispersal of the highly human pathogenic clones ST152-MSSA and ST-80-MRSA in animals. It suggests the ability of some clones to cross the species barrier and jump between humans and several animal species.
El-Aouar Filho, Rachid A.; Nicolas, Aurélie; De Paula Castro, Thiago L.; Deplanche, Martine; De Carvalho Azevedo, Vasco A.; Goossens, Pierre L.; Taieb, Frédéric; Lina, Gerard; Le Loir, Yves; Berkova, Nadia
Some bacterial pathogens modulate signaling pathways of eukaryotic cells in order to subvert the host response for their own benefit, leading to successful colonization and invasion. Pathogenic bacteria produce multiple compounds that generate favorable conditions to their survival and growth during infection in eukaryotic hosts. Many bacterial toxins can alter the cell cycle progression of host cells, impairing essential cellular functions and impeding host cell division. This review summarizes current knowledge regarding cyclomodulins, a heterogeneous family of bacterial effectors that induce eukaryotic cell cycle alterations. We discuss the mechanisms of actions of cyclomodulins according to their biochemical properties, providing examples of various cyclomodulins such as cycle inhibiting factor, γ-glutamyltranspeptidase, cytolethal distending toxins, shiga toxin, subtilase toxin, anthrax toxin, cholera toxin, adenylate cyclase toxins, vacuolating cytotoxin, cytotoxic necrotizing factor, Panton-Valentine leukocidin, phenol soluble modulins, and mycolactone. Special attention is paid to the benefit provided by cyclomodulins to bacteria during colonization of the host. PMID:28589102
Rachid A. El-Aouar Filho
Full Text Available Some bacterial pathogens modulate signaling pathways of eukaryotic cells in order to subvert the host response for their own benefit, leading to successful colonization and invasion. Pathogenic bacteria produce multiple compounds that generate favorable conditions to their survival and growth during infection in eukaryotic hosts. Many bacterial toxins can alter the cell cycle progression of host cells, impairing essential cellular functions and impeding host cell division. This review summarizes current knowledge regarding cyclomodulins, a heterogeneous family of bacterial effectors that induce eukaryotic cell cycle alterations. We discuss the mechanisms of actions of cyclomodulins according to their biochemical properties, providing examples of various cyclomodulins such as cycle inhibiting factor, γ-glutamyltranspeptidase, cytolethal distending toxins, shiga toxin, subtilase toxin, anthrax toxin, cholera toxin, adenylate cyclase toxins, vacuolating cytotoxin, cytotoxic necrotizing factor, Panton-Valentine leukocidin, phenol soluble modulins, and mycolactone. Special attention is paid to the benefit provided by cyclomodulins to bacteria during colonization of the host.
Chu, Chishih; Wei, Yajiun; Chuang, Shih-Te; Yu, Changyou; Changchien, Chih-Hsuan; Su, Yaochi
A total of 117 mastitis-associated Staphylococcus aureus isolates from cow, goat, and human patients were analyzed for differences in antibiotic susceptibility, virulence genes, and genotypes using accessory gene regulator (agr) typing, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Multidrug-resistant (MDR) S. aureus were commonly found in all sources, though they were predominantly found in human and goat isolates. Almost 70% of the isolates were resistant to ampicillin and penicillin. Host-associated virulence genes were identified as follows: tst, a gene encoding toxic shock syndrome toxin, was found in goat isolates; lukED and lukM, genes encoding leukocidin, found in cow isolates; lukPV, a gene encoding leukocidin, found in human isolates; and eta, a gene encoding for exfoliative toxin, found in both human and cow isolates. All four types of hemolysin, α, β, γ, and δ, were identified in human isolates, three types (α, γ, and δ), were identified in cow isolates, and two types (α and δ) were identified in goat isolates. Agr-typing determined agr1 to be the main subtype in human and cow isolates. PFGE and MLST analysis revealed the presence of diverse genotypes among the three sources. In conclusion, mastitis-associated, genetically diverse strains of MDR S. aureus differed in virulence genes among human, cow, and goat isolates.
Staphylococcus aureus (Staph Infection) In every pregnancy, a woman starts out with a 3-5% chance of having a baby with ... from your health care provider. What is a staph infection? Staphylococcus aureus (staph) is a type of ...
Staphylococcus aureus is a dangerous pathogen that causes a variety of severe diseases. The virulence of S. aureus is defined by a large repertoire of virulence factors, among which secreted toxins play a preeminent role. Many S. aureus toxins damage biological membranes, leading to cell death. In particular, S. aureus produces potent hemolysins and leukotoxins. Among the latter, some were recently identified to lyse neutrophils after ingestion, representing an especially powerful weapon against bacterial elimination by innate host defense. Furthermore, S. aureus secretes many factors that inhibit the complement cascade or prevent recognition by host defenses. Several further toxins add to this multi-faceted program of S. aureus to evade elimination in the host. This review will give an overview over S. aureus toxins focusing on recent advances in our understanding of how leukotoxins work in receptor-mediated or receptor-independent fashions. Published by Elsevier Ltd.
Artursson, Karin; Söderlund, Robert; Liu, Lihong; Monecke, Stefan; Schelin, Jenny
Reducing the prevalence of mastitis caused by Staphylococcus aureus (S. aureus) is essential to improve animal health and reduce economic losses for farmers. The clinical outcome of acute mastitis and risk of progression to persistent mastitis can, at least to some extent, be related to genetic variants of the strain causing the infection. In the present study we have used microarrays to investigate the presence of virulence genes in S. aureus isolates from dairy cows with acute clinical mastitis (n=70) and correlated the findings to other genotypic and phenotypic characteristics. Among the most commonly found virulence factors were genes encoding several hemolysin types, leukocidins D and lukM/lukF-P83, clumping factors A and B, fibrinogen binding protein and fibronectin-binding protein A. Some virulence factors e.g. fibronectin-binding protein B and Staphylococcus aureus surface protein G were less common. Genes coding for several staphylococcal enterotoxins and toxic shock syndrome toxin-1 (TSST-1) were commonly found, especially in one major pulsotype. No beta-lactamase genes were found in any common pulsotype, while present in some rare pulsotypes, indicated to be of human origin. Production of TSST-1, enterotoxins, hemolysins and beta-lactamase could all be positively correlated to presence of the corresponding genes. This study reveals a number of genotypic differences and similarities among common and rare pulsotypes of S. aureus from cases of mastitis in Sweden. The results could help the design of diagnostic tools to guide on-farm interventions according to the expected impact on udder health from a specific S. aureus genotype. Copyright © 2016 Elsevier B.V. All rights reserved.
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.
Spanu, Vincenzo; Spanu, Carlo; Virdis, Salvatore; Cossu, Francesca; Scarano, Christian; De Santis, Enrico Pietro Luigi
Contamination of dairy products with Staphylococcus aureus can be of animal or human origin. The host pathogen relationship is an important factor determining genetic polymorphism of the strains and their potential virulence. The aim of the present study was to carry out an extensive characterization of virulence factors and to study the genetic variability of S. aureus strains isolated from raw ewe's milk cheese. A total of 100 S. aureus strains isolated from cheese samples produced in 10 artisan cheese factories were analyzed for the presence of enterotoxins (sea-see) and enterotoxins-like genes (seh, sek, sel, sem, seo, sep), leukocidins, exfoliatins, haemolysins, toxic shock syndrome toxin 1 (TSST-1) and the accessory gene regulator alleles (agr). Strains were also typed using pulsed-field gel electrophoresis (PFGE). AMOVA analysis carried out on PFGE and PCR data showed that the major component explaining genetic distance between strains was the dairy of origin. Of the total isolates 81% had a pathogenicity profile ascribable to "animal" biovar while 16% could be related to "human" biovar. The biovar allowed to estimate the most likely origin of the contamination. Minimum inhibitory concentrations (MICs) of nine antimicrobial agents and the presence of the corresponding genes coding for antibiotic resistance was also investigated. 18 strains carrying blaZ gene showed resistance to ampicillin and penicillin and 6 strains carrying tetM gene were resistant to tetracycline. The presence of mecA gene and methicillin resistance, typical of strains of human origin, was never detected. The results obtained in the present study confirm that S. aureus contamination in artisan cheese production is mainly of animal origin. Copyright © 2011. Published by Elsevier B.V.
Snel, Gustavo G M; Monecke, Stefan; Ehricht, Ralf; Piccinini, Renata
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.
Deurenberg, Ruud H; Stobberingh, Ellen E
A broad variety of infections, ranging from minor infections of the skin to post-operative wound infections can be caused by Staphylococcus aureus. The adaptive power of S. aureus to antibiotics leaded, in the early 1960s, to the emergence of methicillin-resistant S. aureus (MRSA). The cause of
Price, Lance B.; Stegger, Marc; Hasman, Henrik
Since its discovery in the early 2000s, methicillin-resistant Staphylococcus aureus (MRSA) clonal complex 398 (CC398) has become a rapidly emerging cause of human infections, most often associated with livestock exposure. We applied whole-genome sequence typing to characterize a diverse collectio...
P M den Reijer
Full Text Available The ability of Staphylococcus aureus to successfully colonize (abiotic surfaces may be explained by biofilm formation and the actions of virulence factors. The aim of the present study was to establish the presence of 52 proteins, including virulence factors such as alpha-toxin, during biofilm formation of five different (methicillin resistant S. aureus strains on Leiden human epidermal models (LEMs and polystyrene surfaces (PS using a competitive Luminex-based assay.All five S. aureus strains formed biofilms on PS, whereas only three out of five strains formed biofilms on LEMs. Out of the 52 tested proteins, six functionally diverse proteins (ClfB, glucosaminidase, IsdA, IsaA, SACOL0688 and nuclease were detected in biofilms of all strains on both PS and LEMs. At the same time, four toxins (alpha-toxin, gamma-hemolysin B and leukocidins D and E, two immune modulators (formyl peptide receptor-like inhibitory protein and Staphylococcal superantigen-like protein 1, and two other proteins (lipase and LytM were detectable in biofilms by all five S. aureus strains on LEMs, but not on PS. In contrast, fibronectin-binding protein B (FnbpB was detectable in biofilms by all S. aureus biofilms on PS, but not on LEMs. These data were largely confirmed by the results from proteomic and transcriptomic analyses and in case of alpha-toxin additionally by GFP-reporter technology.Functionally diverse virulence factors of (methicillin-resistant S. aureus are present during biofilm formation on LEMs and PS. These results could aid in identifying novel targets for future treatment strategies against biofilm-associated infections.
den Reijer, P M; Haisma, E M; Lemmens-den Toom, N A; Willemse, J; Koning, R I; Koning, R A; Demmers, J A A; Dekkers, D H W; Rijkers, E; El Ghalbzouri, A; Nibbering, P H; van Wamel, W
The ability of Staphylococcus aureus to successfully colonize (a)biotic surfaces may be explained by biofilm formation and the actions of virulence factors. The aim of the present study was to establish the presence of 52 proteins, including virulence factors such as alpha-toxin, during biofilm formation of five different (methicillin resistant) S. aureus strains on Leiden human epidermal models (LEMs) and polystyrene surfaces (PS) using a competitive Luminex-based assay. All five S. aureus strains formed biofilms on PS, whereas only three out of five strains formed biofilms on LEMs. Out of the 52 tested proteins, six functionally diverse proteins (ClfB, glucosaminidase, IsdA, IsaA, SACOL0688 and nuclease) were detected in biofilms of all strains on both PS and LEMs. At the same time, four toxins (alpha-toxin, gamma-hemolysin B and leukocidins D and E), two immune modulators (formyl peptide receptor-like inhibitory protein and Staphylococcal superantigen-like protein 1), and two other proteins (lipase and LytM) were detectable in biofilms by all five S. aureus strains on LEMs, but not on PS. In contrast, fibronectin-binding protein B (FnbpB) was detectable in biofilms by all S. aureus biofilms on PS, but not on LEMs. These data were largely confirmed by the results from proteomic and transcriptomic analyses and in case of alpha-toxin additionally by GFP-reporter technology. Functionally diverse virulence factors of (methicillin-resistant) S. aureus are present during biofilm formation on LEMs and PS. These results could aid in identifying novel targets for future treatment strategies against biofilm-associated infections.
Zou, Wen; Cerniglia, Carl E; Chen, Huizhong
Azoreductase(s) catalyze a NAD(P)H-dependent reaction in bacteria to metabolize azo dyes to colorless aromatic amines. Azoreductases from bacteria represent a novel family of enzymes with little similarity to other reductases. This unit will describe the current methods for measuring azoreductase from Staphylococcus aureus, which has been suggested to serve as a model strain to study the azo dye degradation by human skin microflora.
Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA is a major human health problem and recently, domestic animals, in particular pigs and poultry are discussed as carriers and possible reservoirs of MRSA. 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
El-Adawy, Hosny; Ahmed, Marwa; Hotzel, Helmut; Monecke, Stefan; Schulz, Jochen; Hartung, Joerg; Ehricht, Ralf; Neubauer, Heinrich; Hafez, Hafez M
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
Maželienė, Žaneta; Kaukėnienė, Renata; Antuševas, Aleksandras; Pavilonis, Alvydas
Objective. To determine the prevalence of Staphylococcus aureus strains among hospitalized patients at the beginning of their hospitalization and during their treatment and the resistance of strains to antibiotics, and to evaluate epidemiologic characteristics of these strains. Patients and methods. Sixty-one patients treated at the Department of Cardiac, Thoracic and Vascular Surgery were examined. Identification of Staphylococcus aureus strains was performed using plasmacoagulase and DNase ...
High diversity of genetic lineages and virulence genes in nasal Staphylococcus aureus isolates from donkeys destined to food consumption in Tunisia with predominance of the ruminant associated CC133 lineage
Full Text Available Abstract Background The objective of this study was to determine the genetic lineages and the incidence of antibiotic resistance and virulence determinants of nasal Staphylococcus aureus isolates of healthy donkeys destined to food consumption in Tunisia. Results Nasal swabs of 100 donkeys obtained in a large slaughterhouse in 2010 were inoculated in specific media for S. aureus and methicillin-resistant S. aureus (MRSA recovery. S. aureus was obtained in 50% of the samples, being all of isolates methicillin-susceptible (MSSA. Genetic lineages, toxin gene profile, and antibiotic resistance mechanisms were determined in recovered isolates. Twenty-five different spa-types were detected among the 50 MSSA with 9 novel spa-types. S. aureus isolates were ascribed to agr type I (37 isolates, III (7, II (4, and IV (2. Sixteen different sequence-types (STs were revealed by MLST, with seven new ones. STs belonging to clonal clomplex CC133 were majority. The gene tst was detected in 6 isolates and the gene etb in one isolate. Different combinations of enterotoxin, leukocidin and haemolysin genes were identified among S. aureus isolates. The egc-cluster-like and an incomplete egc-cluster-like were detected. Isolates resistant to penicillin, erythromycin, fusidic acid, streptomycin, ciprofloxacin, clindamycin, tetracycline, or chloramphenicol were found and the genes blaZ, erm(A, erm(C, tet(M, fusC were identified. Conclusions The nares of donkeys frequently harbor MSSA. They could be reservoirs of the ruminant-associated CC133 lineage and of toxin genes encoding TSST-1 and other virulence traits with potential implications in public health. CC133 seems to have a broader host distribution than expected.
Full Text Available Abstract Background The incidence of pediatric infections due to community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA, including children with no identifiable risk factors, has increased worldwide in the last decade. This suggests that healthy children may constitute a reservoir of MRSA in the community. In this study, nested within a larger one on nasopharyngeal ecology, we aimed to: (i evaluate the prevalence of MRSA colonizing young children in Portugal; and (ii compare results with those obtained in a study conducted a decade ago, when this prevalence was Methods In the years 2006, 2007, and 2009, nasopharyngeal samples were obtained from 2,100 children aged up to 6 years attending day-care centers. S. aureus were isolated by routine procedures and strains were tested for susceptibility against a panel of 12 antimicrobial agents. MRSA isolates were further characterized by SmaI-PFGE profiling, MLST, spa typing, SCCmec typing, and presence of virulence factors. Results Seventeen percent of the children carried S. aureus. Among the 365 isolates, non-susceptibility rates were 88% to penicillin, 14% to erythromycin, 6% to clindamycin, 2% to tetracycline, and spa type t148; the other was ST939-IVa (ST939 is a single locus variant (SLV of ST72, spa type t324. The third strain was related to USA300 (ST8-IV being characterized by ST931 (SLV of ST8-VI, spa type t008. The three MRSA strains were PVL-negative, but all carried LukE-LukD leukocidin, hemolysins gamma, gamma variant and beta, and staphylococcal enterotoxin sel. Conclusions Our results, based on analysis of S. aureus isolated from nasopharyngeal samples, suggest that in Portugal the prevalence of CA-MRSA carriage in healthy young children remains extremely low favoring the exclusion of this group as a reservoir of such isolates.
Shamsutdinov, A F; Tiurin, Iu A
Main scientific-research studies regarding protein bacterial toxins of the most widespread bacteria that belong to Staphylococcus spp. genus and in particular the most pathogenic species for humans--Staphylococcus aureus, are analyzed. Structural and biological properties of protein toxins that have received the name of staphylococcus pyrogenic toxins (PTSAg) are presented. Data regarding genetic regulation of secretion and synthesis of these toxins and 3 main regulatory genetic systems (agr--accessory gene regulator, xpr--extracellular protein regulator, sar--staphylococcal accessory regulator) that coordinate synthesis of the most important protein toxins and enzymes for virulence of S. aureus, are presented.
Introduction: Staphylococcus aureus (S. aureus) is one of the most common causes of both community and hospital acquired bacterial infection. There is strong correlation between S aureus nasal carriage and disease progress. Nasal carriage is high among health care workers. Inappropriate usage of antibiotic may
Nasal carriage of Staphylococcus aureus has been demonstrated to be a major risk factor for invasive S. aureus infections in various population including children. The extent of S. aureus carriage in Sierra Leonean children is largely unknown. To determine the prevalence and pattern of antibiotic susceptibility of nasal S.
Staphylococcus aureus is a major pathogen in nosocomial infections. Up to 30% of UCI related infections are caused by S. aureus. In this thesis we explore both clinical and molecular aspects of patient-to-patient transmission of S. aureus. We performed a European ICU study exploring infection
Methicillin-resistant Staphylococcus aureus (S. aureus) (MRSA), resistant to all antibiotics including Vancomycin, has been reported in Japan, USA, Canada and Brazil. Hence, the main objective of this study was to evaluate the possible presence of Vancomycin resistant or intermediate S.aureus in Karachi. A total of 850 ...
Full Text Available Abstract During routinely screening (50.000 milk samples on an annual basis 14 MRSA ST398 strains were identified in the period of January 2008 to September 2008 in 14 different dairy herds located in the provinces Overijssel and Gelderland, The Netherlands. Molecular analysis was performed by Cfr9I PFGE, ST398-specific diagnostic PCR, spa typing, SCCmec typing and Panton-Valentine Leukocidin (PVL gene PCR. The molecular analyses of 14 MRSA (one MRSA strain per herd strains revealed that all strains belong to ST398 with 3 closely related spa types (t011, t108 and t889, all commonly found in pigs and carry 2 different SCCmec types, IVa and V. All MRSA strains were resistant to two or more classes of antibiotics and also PVL negative. The majority of farms (n = 9, 64% harboured combined livestock with both cows and pigs present. Our study contributes to the growing evidence that MRSA ST398 is transmitted among various animal species and can be considered as an etiological agent of mastitis in dairy cows.
Full Text Available The infection of bacterial organisms generally causes cell death to facilitate microbial invasion and immune escape, both of which are involved in the pathogenesis of infectious diseases. In addition to the intercellular infectious processes, pathogen-produced/secreted enterotoxins (mostly exotoxins are the major weapons that kill host cells and cause diseases by inducing different types of cell death, particularly apoptosis and necrosis. Blocking these enterotoxins with synthetic drugs and vaccines is important for treating patients with infectious diseases. Studies of enterotoxin-induced apoptotic and necrotic mechanisms have helped us to create efficient strategies to use against these well-characterized cytopathic toxins. In this article, we review the induction of the different types of cell death from various bacterial enterotoxins, such as staphylococcal enterotoxin B, staphylococcal alpha-toxin, Panton-Valentine leukocidin, alpha-hemolysin of Escherichia coli, Shiga toxins, cytotoxic necrotizing factor 1, heat-labile enterotoxins, and the cholera toxin, Vibrio cholerae. In addition, necrosis caused by pore-forming toxins, apoptotic signaling through cross-talk pathways involving mitochondrial damage, endoplasmic reticulum stress, and lysosomal injury is discussed.
Frees, Dorte; Ingmer, Hanne
Staphylococcus aures are prominent members of the normal flora of humans and animals, but are also a major cause of mild and severe infections. To persist and disseminate in the human host, and to survive in environmental settings, such as hospitals, S. aureus have developed a plethora of cellular...
G. Giacinti; Amatiste, S.; A. Tammaro; D. Sagrafoli; G. Giangolini; R. Rosati
A total of 366 raw milk samples from 30 sheep farms were examined quantitatively for Staphylococcus aureus. Enterotoxin production by strains of Staphylococcus aureus isolated was investigated. S. aureus was detected in 19 farms (63,3%). The ability to synthetise enterotoxins was found in ten strains (52,6%). Production of staphylococcal enterotoxins C (SEC) was recorded in 6 (60%) and production of SEC together with staphylococcal enterotoxin A (SEA) in 4 (40%) staphylococcal isolates. Raw m...
Full Text Available The Gram-positive bacterium Staphylococcus aureus is one of the most frequent pathogens that causes severe morbidity and mortality throughout the world. S. aureus can infect skin and soft tissues or become invasive leading to diseases such as pneumonia, endocarditis, sepsis or toxic shock syndrome. In contrast, S. aureus is also a common commensal microbe and is often part of the human nasal microbiome without causing any apparent disease. In this review, we explore the immunomodulation and disease tolerance mechanisms that promote commensalism to S. aureus.
Paling, Fleur P|info:eu-repo/dai/nl/413968669; Wolkewitz, Martin; Bode, Lonneke G M; Klein Klouwenberg, Peter M C|info:eu-repo/dai/nl/33706864X; Ong, David S Y; Depuydt, Pieter; de Bus, Liesbet; Sifakis, Frangiscos; Bonten, Marc J M|info:eu-repo/dai/nl/123144337; Kluijtmans, Jan|info:eu-repo/dai/nl/323262139
OBJECTIVE: To quantify the incidence of intensive care unit (ICU) acquired pneumonia caused by Staphylococcus aureus (S. aureus) and its association with S. aureus colonization at ICU admission. METHODS: This was a post-hoc analysis of two cohort studies in critically ill patients. The primary
Taha, Aza Bahadeen
Staphylococcus aureus is the main cause of diabetic foot infection with the patient's endogenous flora as the principal source. Nasal carriage of S. aureus has been identified as an important risk factor for the acquisition of diabetic foot infections. The study assessment the associations of S. aureus with methicillin resistant S. aureus were isolation from diabetic foot infection and nasal carriage of the same patients and their antibiotic susceptibility profile. Diagnosis of S. aureus and methicillin resistant S. aureus were carried out by using standard procedures. Antibiotic sensitivity profiles were determent by breakpoint dilution method. Out of 222 S. aureus isolation, 139 (62.61%) were isolated from the diabetic foot and 83 (37.39%) from the nasal carriage. Seventy one (30.87%) of the patients were S. aureus infection diabetic foot with nasal carriage. Among diabetic foot infection and nasal carriage patients, 40.85% of S. aureus were considered as methicillin resistant S. aureus. Rifampicin (96.40%) and Levofloxacin (91.44%) were active against S. aureus. Patients at strong risk for methicillin resistant S. aureus nasal carriage and subsequent diabetic foot infection with high resistance to antibiotics. Copyright © 2012 Elsevier Ltd. All rights reserved.
Hedin, Göran; Fang, Hong
Thirty-nine methicillin-resistant Staphylococcus aureus (MRSA) isolates with diverse genetic backgrounds and two reference strains were correctly identified as S. aureus on CHROMagar MRSA and S. aureus ID media. Growth inhibition on CHROMagar MRSA was noted. A combination of cefoxitin disk and S. aureus ID was found suitable for rapid MRSA screening.
In our region, although methicillin resistance increased in S. aureus strains, because of the unavailability and the high cost of alternative antibiotics, gentamycin is still suggested as an alternative for treatment of S. aureus infections. These results however indicate that vancomycin seemed to be the only antimicrobial agent ...
Carriers of Staphylococcus aureus have an important role in its dissemination. The colonization rates of S. aureus in anterior nose nares from 210 healthy volunteers (70 from the non-hospital adult personnel in the community, 68 from clinical students and 72 from healthcare workers “HCWs” in 6 hospitals) in the eastern ...
Nosocomial infections caused by methicillin-resistant strains of Staphylococcus aureus often pose therapeutic dilemma to the clinicians because of the multi resistant nature of these strains of Staphylococcus aureus. Outbreaks of both nosocomial and community acquired infections are also frequent and difficult to control.
INTRODUCTION. Bacterial conjunctivitis is common usually self-limiting. The most common causative organisms are staphylococcus epidermis and staphylococcus aureus (S. aureus). Bacterial conjunctivitis is rarely sight threatening. However, accurate diagnosis and prompt treatment at the primary level is important as it ...
BACKGROUND: Staphylococcus aureus is one of the major causes of community and hospital acquired infections. The emergence of methicillin resistant strains of Staphylococcus aureus in the hospitals and the community is a serious health problem. The aim of this study was to determine the nasal carriage and ...
Staphylococcus aureus is an Important agent of food poisoning. In many countries, it is the main bacterial organism responsible for diseases caused by exotoxin production and direct invasion with systemic dissemination. In poultry, S. aureus is associated with many clinical syndromes including tenosynovitis, omphalitis, ...
Introduction: methicillin-resistant Staphylococcus aureus (MRSA) has been recognized as important nosocomial pathogens worldwide. S aureus may induce clinically manifested diseases, or the host may remain completely asymptomatic. Methods: a cross-sectional hospital-based study was conducted from October 2012 ...
N.J. Verkaik (Nelianne); O. Dauwalder (Olivier); K. Antri (Kenza); I. Boubekri (Ilhem); C.P. de Vogel (Corné); C. Badiou (Cédric); M. Bes (Michèle); F. Vandenesch (François); M. Tazir (Mohammed); H. Hooijkaas (Herbert); H.A. Verbrugh (Henri); A.F. van Belkum (Alex); J. Etienne (Jerome); G. Lina (Gérard); N. Ramdani-Bouguessa (Nadjia); W.J.B. van Wamel (Willem)
textabstractAB - BACKGROUND: Toxins are important Staphylococcus aureus virulence factors, but little is known about their immunogenicity during infection. Here, additional insight is generated. METHODS: Serum samples from 206 S. aureus-infected patients and 201 hospital-admitted control subjects
BACKGROUND: Staphylococcus aureus is one of the major causes of community and hospital acquired infections. The emergence of methicillin resistant strains of. Staphylococcus aureus in the hospitals and the community is a serious health problem. The aim of this study was to determine the nasal carriage and ...
Sokoto Journal of Veterinary Sciences, Volume 11 (Number 1). June, 2013. 51 ... Staphylococcus aureus is an Important agent of food poisoning. In many ..... enterotoxicity of Staphylococcus aureus isolated from the hands and nasal cavities of flight catering employees. Journal of Food. Protection, 11, 1487–1491. Hill JE ...
... Methicillin Resistant S. aureus (MRSA) in the studied population. Clinical isolates of S. aureus strains were collected from Medical Microbiology Unit of University College Hospital, Ibadan between May and October, 2012. The isolates were confirmed through growth on Mannitol Salt Agar (MSA) and tube coagulase test.
Many medical procedures breach or suppress patients’ natural defences, leaving them vulnerable to infections which would not occur in healthy humans: “healthcare-associated infections”. Healthcare-associated infections caused by the bacterium Staphylococcus aureus (S. aureus) are probably the most
Haslund, P; Bangsgaard, N; Jarløv, J O
BACKGROUND: The role of bacterial infections in hand eczema (HE) remains to be assessed. OBJECTIVES: To determine the prevalence of Staphylococcus aureus in patients with HE compared with controls, and to relate presence of S. aureus, subtypes and toxin production to severity of HE. METHODS......: Bacterial swabs were taken at three different visits from the hand and nose in 50 patients with HE and 50 controls. Staphylococcus aureus was subtyped by spa typing and assigned to clonal complexes (CCs), and isolates were tested for exotoxin-producing S. aureus strains. The Hand Eczema Severity Index...... was used for severity assessment. RESULTS: Staphylococcus aureus was found on the hands in 24 patients with HE and four controls (P
Barbara M. Bröker
Full Text Available Staphylococcus aureus (S. aureus is a dangerous pathogen and a leading cause of both nosocomial and community acquired bacterial infection worldwide. However, on the other hand, we are all exposed to this bacterium, often within the first hours of life, and usually manage to establish equilibrium and coexist with it. What does the adaptive immune system contribute toward lifelong control of S. aureus? Will it become possible to raise or enhance protective immune memory by vaccination? While in the past the S. aureus-specific antibody response has dominated this discussion, the research community is now coming to appreciate the role that the cellular arm of adaptive immunity, the T cells, plays. There are numerous T cell subsets, each with differing functions, which together have the ability to orchestrate the immune response to S. aureus and hence to tip the balance between protection and pathology. This review summarizes the state of the art in this dynamic field of research.
Full Text Available A total of 366 raw milk samples from 30 sheep farms were examined quantitatively for Staphylococcus aureus. Enterotoxin production by strains of Staphylococcus aureus isolated was investigated. S. aureus was detected in 19 farms (63,3%. The ability to synthetise enterotoxins was found in ten strains (52,6%. Production of staphylococcal enterotoxins C (SEC was recorded in 6 (60% and production of SEC together with staphylococcal enterotoxin A (SEA in 4 (40% staphylococcal isolates. Raw milk products are vulnerable to contamination by S. aureus. Strategies to reduce the occurrence of S. aureus in bulk milk are of particular importance on farms where milk is used for raw milk products.
ten Broeke-Smits, Nicole J P; Pronk, Tessa E; Jongerius, Ilse; Bruning, Oskar; Wittink, Floyd R; Breit, Timo M; van Strijp, Jos A G; Fluit, Ad C; Boel, C H Edwin
In bacteria, gene regulation is one of the fundamental characteristics of survival, colonization and pathogenesis. Operons play a key role in regulating expression of diverse genes involved in metabolism and virulence. However, operon structures in pathogenic bacteria have been determined only by in silico approaches that are dependent on factors such as intergenic distances and terminator/promoter sequences. Knowledge of operon structures is crucial to fully understand the pathophysiology of infections. Presently, transcriptome data obtained from growth curves in a defined medium were used to predict operons in Staphylococcus aureus. This unbiased approach and the use of five highly reproducible biological replicates resulted in 93.5% significantly regulated genes. These data, combined with Pearson's correlation coefficients of the transcriptional profiles, enabled us to accurately compile 93% of the genome in operon structures. A total of 1640 genes of different functional classes were identified in operons. Interestingly, we found several operons containing virulence genes and showed synergistic effects for two complement convertase inhibitors transcribed in one operon. This is the first experimental approach to fully identify operon structures in S. aureus. It forms the basis for further in vitro regulation studies that will profoundly advance the understanding of bacterial pathophysiology in vivo.
Carlos Andrés Rodríguez
Full Text Available Objetivo. Revisar la evolución y mecanismos moleculares de la resistencia de Staphylococcus aureus a vancomicina. Fuente de los datos. Se consultó la base de datos MEDLINE y se seleccionaron artículos tipo reportes de caso, estudios bioquímicos, de microscopía electrónica y biología molecular pertinentes. Síntesis. Después de casi 40 años de eficacia ininterrumpida de la vancomicina, en 1997 se reportaron los primeros casos de fracaso terapéutico debido a cepas de Staphylococcus aureus con resistencia intermedia, denominadas VISA (concentración inhibitoria mínima, CIM, 8 a 16 ?g/ml, así como a cepas con resistencia heterogénea hVISA (CIM global = 4 ?g/ml, pero con subpoblaciones VISA, en las cuales la resistencia está mediada por engrosamiento de la pared celular y disminución de su entrecruzamiento, lo que afecta la llegada del antibiótico al blanco principal, los monómeros del peptidoglicano en la membrana plasmática. En 2002 se aisló la primera de las 3 cepas reportadas hasta la fecha con resistencia total al antibiótico, denominadas VRSA (CIM>32 ?g/ml, en las que se encontró el transposón Tn1546 proveniente de Enterococcus spp, responsable del reemplazo de la terminación D-Ala-D-Ala por D-Ala-Dlactato en los precursores de la pared celular con pérdida de la afinidad por el glicopéptido. Conclusiones. La resistencia a vancomicina es una realidad en S. aureus, mediada en el caso de VISA por alteraciones en la pared celular que atrapan el antibiótico antes de llegar al sitio de acción, y en el caso de VRSA, por transferencia desde Enterococcus spp. de genes que llevan a la modificación del blanco molecular.
Full Text Available Staphylococcus aureus is an important pathogen of humans and livestock. It causes a diverse array of diseases, ranging from relatively harmless localized skin infections to life-threatening systemic conditions. Among multiple virulence factors, staphylococci secrete several exotoxins directly associated with particular disease symptoms. These include toxic shock syndrome toxin 1 (TSST-1, enterotoxins, and exfoliative toxins (ETs. The latter are particularly interesting as the sole agents responsible for staphylococcal scalded skin syndrome (SSSS, a disease predominantly affecting infants and characterized by the loss of superficial skin layers, dehydration, and secondary infections. The molecular basis of the clinical symptoms of SSSS is well understood. ETs are serine proteases with high substrate specificity, which selectively recognize and hydrolyze desmosomal proteins in the skin. The fascinating road leading to the discovery of ETs as the agents responsible for SSSS and the characterization of the molecular mechanism of their action, including recent advances in the field, are reviewed in this article.
Luini, M; Cremonesi, P; Magro, G; Bianchini, V; Minozzi, G; Castiglioni, B; Piccinini, R
Staphylococcus aureus is one of the most common mastitis-causing pathogens worldwide. In the last decade, livestock-associated methicillin-resistant S. aureus (LA-MRSA) infections have been described in several species, included the bovines. Hence, this paper investigates the diffusion of MRSA within Italian dairy herds; the strains were further characterized using a DNA microarray, which detects 330 different sequences, including the methicillin-resistance genes mecA and mecC and SCCmec typing. The analysis of overall patterns allows the assignment to Clonal Complexes (CC). Overall 163 S. aureus isolates, collected from quarter milk samples in 61 herds, were tested. MRSA strains were further processed using spa typing. Fifteen strains (9.2%), isolated in 9 herds (14.75%), carried mecA, but none harboured mecC. MRSA detection was significantly associated (Paureus intra-mammary infections (IMI) ≤5%. Ten MRSA strains were assigned to CC398, the remaining ones to CC97 (n=2), CC1 (n=2) or CC8 (n=1). In 3 herds, MRSA and MSSA co-existed: CC97-MRSA with CC398-MSSA, CC1-MRSA with CC8-MSSA and CC398-MRSA with CC126-MSSA. The results of spa typing showed an overall similar profile of the strains belonging to the same CC: t127-CC1, t1730-CC97, t899 in 8 out of 10 CC398. In the remaining 2 isolates a new spa type, t14644, was identified. The single CC8 was a t3092. The SCCmec cassettes were classified as type IV, type V or type IV/V composite. All or most strains harboured the genes encoding the β-lactamase operon and the tetracycline resistance. Streptogramin resistance gene was related to CC398. Enterotoxin and leukocidin genes were carried only by CC1, CC8 and CC97-MRSA. The persistence of MRSA clones characterized by broader host range, in epidemiologically unrelated areas and in dairy herds with low prevalence of S. aureus IMI, might enhance the risk for adaptation to human species. Copyright © 2015 Elsevier B.V. All rights reserved.
... resistant Staphylococcus aureus; Hospital-acquired MRSA (HA-MRSA); Staph - MRSA; Staphylococcal - MRSA ... Most staph germs are spread by skin-to-skin contact (touching). A doctor, nurse, other health care provider, or ...
Brouwer, Matthijs C.; Keizerweerd, Gabriella D.; de Gans, Jan; Spanjaard, Lodewijk; van de Beek, Diederik
We present 9 patients with community acquired Staphylococcus aureus meningitis. Foci of infection outside the central nervous system were present in 8 (89%) patients, mostly endocarditis and pneumonia. Cardiorespiratory complications occurred frequently and 6 patients died (67%). Identification and
, Libya using current testing methods. Methods: One hundred and seventy S. aureus isolates previously identified as MRSA were obtained from three hospitals in Tripoli. All isolates were reidentified by culturing on mannitol salt agar, API 20 ...
Hanada, Yuichi; Sekimizu, Kazuhisa; Kaito, Chikara
Silkworm hemolymph inhibits hemolysin production by Staphylococcus aureus. We purified a factor in the silkworm hemolymph responsible for this inhibitory activity. The final fraction with the greatest specific activity contained 220- and 74-kDa proteins. Determination of the N-terminal amino acid sequence revealed that the 220- and 74-kDa proteins were apolipophorin I and apolipophorin II, respectively, indicating that the factor was apolipophorin (ApoLp). The purified ApoLp fraction showed decreased expression of S. aureus hla encoding α-hemolysin, hlb encoding β-hemolysin, saeRS, and RNAIII, which activate the expression of these hemolysin genes. Injection of an anti-ApoLp antibody into the hemolymph increased the sensitivity of silkworms to the lethal effect of S. aureus. Hog gastric mucin, a mammalian homologue of ApoLp, decreased the expression of S. aureus hla and hlb. These findings suggest that ApoLp in the silkworm hemolymph inhibits S. aureus virulence and contributes to defense against S. aureus infection and that its activity is conserved in mammalian mucin. PMID:21937431
Strommenger, Birgit; Bartels, Mette Damkjær; Kurt, Kevin
To elucidate the evolutionary history of Staphylococcus aureus clonal complex (CC) 8, which encompasses several globally distributed epidemic lineages, including hospital-associated methicillin-resistant S. aureus (MRSA) and the highly prevalent community-associated MRSA clone USA300....
Avila, J G; de Liverant, J G; Martínez, A; Martínez, G; Muñoz, J L; Arciniegas, A; Romo de Vivar, A
We evaluate the mode of action of verbascoside obtained from Buddleja cordata against Staphylococcus aureus by killing kinetics and incorporation of precursors methods. Verbascoside induced lethal effect on S. aureus, by affecting protein synthesis and inhibiting leucine incorporation.
Rasmussen, Rasmus V; Høst, Ulla; Arpi, Magnus
Aims Staphylococcus aureus infective endocarditis (IE) is a critical medical condition associated with a high morbidity and mortality. In the present study, we prospectively evaluated the importance of screening with echocardiography in an unselected S. aureus bacteraemia (SAB) population. Methods...
Balasubramanian, Divya; Harper, Lamia; Shopsin, Bo; Torres, Victor J.
Abstract Staphylococcus aureus is an eminent human pathogen that can colonize the human host and cause severe life-threatening illnesses. This bacterium can reside in and infect a wide range of host tissues, ranging from superficial surfaces like the skin to deeper tissues such as in the gastrointestinal tract, heart and bones. Due to its multifaceted lifestyle, S. aureus uses complex regulatory networks to sense diverse signals that enable it to adapt to different environments and modulate virulence. In this minireview, we explore well-characterized environmental and host cues that S. aureus responds to and describe how this pathogen modulates virulence in response to these signals. Lastly, we highlight therapeutic approaches undertaken by several groups to inhibit both signaling and the cognate regulators that sense and transmit these signals downstream. PMID:28104617
Sandra Davi Traverso
Full Text Available Em uma criação composta por 1800 coelhos, 33% das matrizes apresentaram mastite e lesões cutâneas crostosas e purulentas. Estes animais apresentavam-se entre 10 a- 12 meses de idade e em segunda parição. Quinze coelhos afetados foram sacrificados e necropsiados. Na necropsia, além das lesões cutâneas haviam microabscessos em diversos órgãos. Das amostras coletadas isolou-se Staphylococcus aureus subesp. aureus. S. aureus subesp. aureus também foi isolado de "swab" nasal coletado do tratador encarregado de fazer o diagnóstico de gestação nas coelhas. Histologicamente, havia formação de múltiplos abscessos, presença de bactérias gram positivas em vasos sangüíneos e linfáticos, além de êmbolos bacterianos nos tecidos. Nas mamas, observou-se tecido glandular normal associado a abscessos multifocais delimitados.At a commercial rabbitry which was composed of 1800 New Zealand White rabbits, 30% of the does had presented mastitis and purulent cutaneal lesions. The age of the animals ranged from 10 to 12 months and were at the second parturition. At necropsy, microabscesses were observed in several organs. Bacteriological samples collected from affected animals resulted Staphylococcus aureus subesp. aureus.. Additionally, the same agent has been isolated from a nasal swab collected from the person responsible for the pregnancy diagnosis. Histologically, there were multiple abscesses, gram positive bacteria within blood and lymphatic vessels, and bacterial emboli scattered in the tissues. In the mammas, normal glandular tissue associated with multifocal abscesses were observed.
A total of 70 ear and nasal swab samples collected from 35 persons, 16-hospital population and 19 non-hospital population was examined for presence of Staphylococcus aureus. Eighty percent of the population studied were found to be carriers of S. aureus. Of the 28 positive cases, 35.7% were carriers of S. aureus. in ...
Strains of Staphylococcus aureus were isolated from the anterior nares of healthy pupils and their antibiotic susceptibility patterns were determined. 116 isolates of Staphylococcus aureus (100%) were biochemically characterized as coagulase positive S. aureus. Susceptibility profile of the isolates revealed that 15(14.85%) ...
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Staphylococcus aureus serological reagents. 866... Staphylococcus aureus serological reagents. (a) Identification. Staphylococcus aureus serological reagents are... diagnosis of disease caused by this bacterium belonging to the genus Staphylococcus and provides...
... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Staphylococcus Aureus Bacterin-Toxoid... REQUIREMENTS Inactivated Bacterial Products § 113.115 Staphylococcus Aureus Bacterin-Toxoid. Staphylococcus... Staphylococcus aureus which has been inactivated and is nontoxic. Each serial of biological product containing...
Oct 30, 2008 ... Nasal carriage of staphylococcus aureus (S. aureus) exerts immunomodulatory effects in patients with atopic dermatitis and it may contribute to airway inflammation and allergic response in patients with allergic rhinitis. We investigated the frequency of nasal S. aureus carriage in patients with perennial ...
Community acquired Staphylococcus aureus was isolated from various infectious sites in two private laboratories in Kano-city, Nigeria. A total of 247 (11%) Staphylococcu aureus isolates were recovered from all infectious sites except cerebro-spinal fluid. The least Staphylococcus aureus isolates were found in urine ...
Three Hundred and Sixty fresh cow milk samples were collected from settled Fulani herds in Kaduna State and examined for S. aureus and their antibiotic resistance. Fifty five samples (15.3%) were positive for S. aureus. The occurrence of S. aureus was statistically significant (P<0.005) based on locations. Statistical ...
Full Text Available Staphylococcus aureus is one of the most important contagious mastitis pathogens in dairy cattle. Due to its zoonotic potential, control of S. aureus is not only of great economic importance in the dairy industry but also a significant public health concern. The aim of this study was to decipher the potential of bovine udder associated S. aureus as reservoir for S. aureus contamination in dairy production and processing. From 18 farms, delivering their milk to an alpine dairy plant for the production of smeared semi-hard and hard cheese. 1176 quarter milk (QM samples of all cows in lactation (n = 294 and representative samples form bulk tank milk (BTM of all farms were surveyed for coagulase positive (CPS and coagulase negative Staphylococci (CNS. Furthermore, samples from different steps of the cheese manufacturing process were tested for CPS and CNS. As revealed by chemometric-assisted FTIR spectroscopy and molecular subtyping (spa typing and multi locus sequence typing, dairy cattle represent indeed an important, yet underreported, entrance point of S. aureus into the dairy chain. Our data clearly show that certain S. aureus subtypes are present in primary production as well as in the cheese processing at the dairy plant. However, although a considerable diversity of S. aureus subtypes was observed in QM and BTM at the farms, only certain S. aureus subtypes were able to enter and persist in the cheese manufacturing at the dairy plant and could be isolated from cheese until day fourteen of ripening. Farm strains belonging to the FTIR cluster B1 and B3, which show genetic characteristics (t2953, ST8, enterotoxin profile: sea/sed/sej of the recently described S. aureus genotype B, most successfully contaminated the cheese production at the dairy plant. Thus our study fosters the hypothesis that genotype B S. aureus represent a specific challenge in control of S. aureus in the dairy chain that requires effective clearance strategies and hygienic
Kümmel, Judith; Stessl, Beatrix; Gonano, Monika; Walcher, Georg; Bereuter, Othmar; Fricker, Martina; Grunert, Tom; Wagner, Martin; Ehling-Schulz, Monika
Staphylococcus aureus is one of the most important contagious mastitis pathogens in dairy cattle. Due to its zoonotic potential, control of S. aureus is not only of great economic importance in the dairy industry but also a significant public health concern. The aim of this study was to decipher the potential of bovine udder associated S. aureus as reservoir for S. aureus contamination in dairy production and processing. From 18 farms, delivering their milk to an alpine dairy plant for the production of smeared semi-hard and hard cheese. one thousand hundred seventy six one thousand hundred seventy six quarter milk (QM) samples of all cows in lactation (n = 294) and representative samples form bulk tank milk (BTM) of all farms were surveyed for coagulase positive (CPS) and coagulase negative Staphylococci (CNS). Furthermore, samples from different steps of the cheese manufacturing process were tested for CPS and CNS. As revealed by chemometric-assisted FTIR spectroscopy and molecular subtyping (spa typing and multi locus sequence typing), dairy cattle represent indeed an important, yet underreported, entrance point of S. aureus into the dairy chain. Our data clearly show that certain S. aureus subtypes are present in primary production as well as in the cheese processing at the dairy plant. However, although a considerable diversity of S. aureus subtypes was observed in QM and BTM at the farms, only certain S. aureus subtypes were able to enter and persist in the cheese manufacturing at the dairy plant and could be isolated from cheese until day 14 of ripening. Farm strains belonging to the FTIR cluster B1 and B3, which show genetic characteristics (t2953, ST8, enterotoxin profile: sea/sed/sej) of the recently described S. aureus genotype B, most successfully contaminated the cheese production at the dairy plant. Thus, our study fosters the hypothesis that genotype B S. aureus represent a specific challenge in control of S. aureus in the dairy chain that requires
While there was no bacterial growth after 48hrs incubation recorded for group one, only 5(13.9%) samples yielded growth of Staphylococcus aureus for group two with 31(86.1%) yielding no bacterial growth. All group three samples yielded profuse growth of which 11(36.7%) yielded Pseudomonas aeruginosa and ...
Datos importantes sobre las infecciones por SARM en Estados Unidos, en las escuelas y los entornos mÃ©dicos. (Title: Methicillin-resistant Staphylococcus aureus (MRSA)Created: 10/2007). Created: 10/22/2007 by National Center for Preparedness, Detection, and Control of Infectious Diseases. Date Released: 11/9/2007.
Clones were defined by Multilocus Sequence Typing (MLST), spa type and Pulsed-Field Gel Electrophoresis (PFGE). Seven S. aureus isolates were recovered from four animals and one from an employee. All were mecA, mecC and tst–negative, whereas, one carried the PVL genes and was isolated from an infected ...
Dreisbach, Annette; Hempel, Kristina; Buist, Girbe; Hecker, Michael; Becher, Doerte; van Dijl, Jan Maarten
Staphylococcus aureus is a widespread opportunistic pathogen that can cause a wide variety of life-threatening diseases. Especially for the colonization of human tissues and the development of invasiveness, surface-exposed proteins are of major importance. In the present studies, we optimized a
Two hundred (200) strains of S. aureus and P. aeruginosa were isolated from clinical samples collected from patients in Murtala Muhammad Specialist Hospital and Infectious Diseases Hospital, Kano. The confirmed isolates were tested for resistance to quinolones by the agar disk diffusion susceptibility test and the agar ...
Andersen, Leif Percival; Nielsen, Xiaohui
INTRODUCTION: Even though methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of nosocomial infections, it may often be difficult to evaluate the exact route of transmission. METHODS: In this study, we describe four cases of nosocomial transmission of MRSA in a hospital with a low...
Glasner, C; Pluister, G; Westh, H
Methicillin-resistant Staphylococcus aureus (MRSA) belonging to the multilocus sequence type clonal complex 59 (MLST CC59) is the predominant community-associated MRSA clone in Asia. This clone, which is primarily linked with the spa type t437, has so far only been reported in low numbers among...
Background: Staphylococcus aureus, a mainly acquired hospital infection is responsible for many suppurative lesions and has demonstrated the ability of developing resistance to many antimicrobial agents leading to life threatening infections and long hospital stay. Objective: To determined the prevalence and antibiotic ...
Feb 1, 2010 ... The main aim of this project is to produce polyclonal antibodies directed against the Staphylococcus aureus protein A and their use to appreciate bacteriological analysis of milk quality. In this context, an immunization produce was set up to test and detect in a batch of animals the convenient responder to.
Vonk, A. G.; Vandenbroucke-Grauls, C. M. J. E.
Methicillin-resistant Staphylococcus aureus (MRSA) infections have been confined to healthcare centres for decades. However, MRSA infections are increasingly seen in young healthy individuals with no exposure to healthcare centres. These community-acquired MRSA (CA-MRSA) strains differ from
H.F.L. Wertheim (Heiman)
textabstractAn overview and the latest insights regarding S. aureus nasal carriage, associated risks of developing infections and possible preventive measures, will be given in Chapter 2. Since mupirocin efficacy studies in preventing nosocomial infections have only been performed in surgical and
High frequency of S. aureus was observed in toilet seat with perecentage distribution of 78%, followed by floor with percentage distribution of 70% and locker with percentage distribution of 65% and the lowest frequency occurence was observed in switch with percentage distribution of 30%. Frequency occurrence of S.
Koukos, Georgios; Sakellari, Dimitra; Arsenakis, Minas; Tsalikis, Lazaros; Slini, Theodora; Konstantinidis, Antonios
To assess the prevalence of Staphylococcus aureus and methicillin resistant Staphylococcus aureus (MRSA) in plaque and tongue samples from systemically healthy subjects with periodontal health, gingivitis or chronic periodontitis. After screening 720 potentially eligible subjects, 154 systemically healthy participants were ultimately enrolled in the current study. Subgingival samples were taken from the first molars and the tongue and analyzed for the presence of S. aureus and MRSA by polymerase chain reaction (PCR), using primers and conditions previously described in the literature. In addition, samples were taken from deep periodontal pockets of chronic periodontitis patients. Statistical analysis was performed by applying non-parametric tests (Kruskal-Wallis for clinical parameters, and z-test with Bonferroni corrections for distributions of assessed parameters). All comparisons were set at the 0.05 significance level. S. aureus was detected in 18% of all participants and in 10% of the samples tested. No significant differences were found in its distribution among the three investigated groups (z-test for proportions with Bonferroni corrections, p>0.05). The mecA gene was not present in any of the S. aureus found. S. aureus can be found in the oral environment regardless of the periodontal conditions and therefore should be considered as a member of the transient flora not participating in periodontal pathology. Subgingival sites and tongue surfaces seem to be an unusual habitat of MRSA. Copyright © 2015 Elsevier Ltd. All rights reserved.
Thangamani, Shankar; Mohammad, Haroon; Abushahba, Mostafa F. N.; Hamed, Maha I.; Sobreira, Tiago J. P.; Hedrick, Victoria E.; Paul, Lake N.; Seleem, Mohamed N.
The rapid rise of bacterial resistance to traditional antibiotics combined with the decline in discovery of novel antibacterial agents has created a global public health crisis. Repurposing existing drugs presents an alternative strategy to potentially expedite the discovery of new antimicrobial drugs. The present study demonstrates that simvastatin, an antihyperlipidemic drug exhibited broad-spectrum antibacterial activity against important Gram-positive (including methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative pathogens (once the barrier imposed by the outer membrane was permeabilized). Proteomics and macromolecular synthesis analyses revealed that simvastatin inhibits multiple biosynthetic pathways and cellular processes in bacteria, including selective interference of bacterial protein synthesis. This property appears to assist in simvastatin’s ability to suppress production of key MRSA toxins (α-hemolysin and Panton-Valentine leucocidin) that impair healing of infected skin wounds. A murine MRSA skin infection experiment confirmed that simvastatin significantly reduces the bacterial burden and inflammatory cytokines in the infected wounds. Additionally, simvastatin exhibits excellent anti-biofilm activity against established staphylococcal biofilms and demonstrates the ability to be combined with topical antimicrobials currently used to treat MRSA skin infections. Collectively the present study lays the foundation for further investigation of repurposing simvastatin as a topical antibacterial agent to treat skin infections. PMID:26553420
Lee, Kayeon; Lee, Jin-Hyung; Ryu, Shi Yong; Cho, Moo Hwan; Lee, Jintae
Stilbenoids have a broad range of beneficial health effects. On the other hand, the emergence of antibiotic-resistant Staphylococcus aureus presents a worldwide problem that requires new antibiotics or nonantibiotic strategies. S. aureus produces α-hemolysin (a pore-forming cytotoxin) that has been implicated in the pathogenesis of sepsis and pneumonia. Furthermore, the biofilms formed by S. aureus constitute a mechanism of antimicrobial resistance. In this study, we investigated the hemolytic and antibiofilm activities of 10 stilbene-related compounds against S. aureus. trans-Stilbene and resveratrol at 10 μg/mL were found to markedly inhibit human blood hemolysis by S. aureus, and trans-stilbene also inhibited S. aureus biofilm formation without affecting its bacterial growth. Furthermore, trans-stilbene and resveratrol attenuated S. aureus virulence in vivo in the nematode Caenorhabditis elegans, which is normally killed by S. aureus. Transcriptional analysis showed that trans-stilbene repressed the α-hemolysin hla gene and the intercellular adhesion locus (icaA and icaD) in S. aureus, and this finding was in line with observed reductions in virulence and biofilm formation. In addition, vitisin B, a stilbenoid tetramer, at 1 μg/mL was observed to significantly inhibit human blood hemolysis by S. aureus.
Matthew M Ramsey
Full Text Available Staphylococcus aureus–human interactions result in a continuum of outcomes from commensalism to pathogenesis. S. aureus is a clinically important pathogen that asymptomatically colonizes ~25% of humans as a member of the nostril and skin microbiota, where it resides with other bacteria including commensal Corynebacterium species. Commensal Corynebacterium spp. are also positively correlated with S. aureus in chronic polymicrobial diabetic foot infections, distinct from acute monomicrobial S. aureus infections. Recent work by our lab and others indicates that microbe-microbe interactions between S. aureus and human skin/nasal commensals, including Corynebacterium species, affect S. aureus behavior and fitness. Thus, we hypothesized that S. aureus interactions with Corynebacterium spp. diminish S. aureus virulence. We tested this by assaying for changes in S. aureus gene expression during in vitro mono- versus coculture with Corynebacterium striatum, a common skin and nasal commensal. We observed a broad shift in S. aureus gene transcription during in vitro growth with C. striatum, including increased transcription of genes known to exhibit increased expression during human nasal colonization and decreased transcription of virulence genes. S. aureus uses several regulatory pathways to transition between commensal and pathogenic states. One of these, the quorum signal accessory gene regulator (agr system, was strongly inhibited in response to Corynebacterium spp. Phenotypically, S. aureus exposed to C. striatum exhibited increased adhesion to epithelial cells, reflecting a commensal state, and decreased hemolysin activity, reflecting an attenuation of virulence. Consistent with this, S. aureus displayed diminished fitness in experimental in vivo coinfection with C. striatum when compared to monoinfection. These data support a model in which S. aureus shifts from virulence towards a commensal state when exposed to commensal Corynebacterium species.
Ramsey, Matthew M.; Freire, Marcelo O.; Gabrilska, Rebecca A.; Rumbaugh, Kendra P.; Lemon, Katherine P.
Staphylococcus aureus–human interactions result in a continuum of outcomes from commensalism to pathogenesis. S. aureus is a clinically important pathogen that asymptomatically colonizes ~25% of humans as a member of the nostril and skin microbiota, where it resides with other bacteria including commensal Corynebacterium species. Commensal Corynebacterium spp. are also positively correlated with S. aureus in chronic polymicrobial diabetic foot infections, distinct from acute monomicrobial S. aureus infections. Recent work by our lab and others indicates that microbe–microbe interactions between S. aureus and human skin/nasal commensals, including Corynebacterium species, affect S. aureus behavior and fitness. Thus, we hypothesized that S. aureus interactions with Corynebacterium spp. diminish S. aureus virulence. We tested this by assaying for changes in S. aureus gene expression during in vitro mono- versus coculture with Corynebacterium striatum, a common skin and nasal commensal. We observed a broad shift in S. aureus gene transcription during in vitro growth with C. striatum, including increased transcription of genes known to exhibit increased expression during human nasal colonization and decreased transcription of virulence genes. S. aureus uses several regulatory pathways to transition between commensal and pathogenic states. One of these, the quorum signal accessory gene regulator (agr) system, was strongly inhibited in response to Corynebacterium spp. Phenotypically, S. aureus exposed to C. striatum exhibited increased adhesion to epithelial cells, reflecting a commensal state, and decreased hemolysin activity, reflecting an attenuation of virulence. Consistent with this, S. aureus displayed diminished fitness in experimental in vivo coinfection with C. striatum when compared to monoinfection. These data support a model in which S. aureus shifts from virulence toward a commensal state when exposed to commensal Corynebacterium species. PMID:27582729
Stefani, Stefania; Chung, Doo Ryeon; Lindsay, Jodi A
decisions with regard to harmonisation of typing methods. A stratified, three-level organisation of testing laboratories was proposed: local; regional; and national. The functions of, and testing methodology used by, each laboratory were defined. The group consensus was to recommend spa and staphylococcal......This article reviews recent findings on the global epidemiology of healthcare-acquired/associated (HA), community-acquired/associated (CA) and livestock-associated (LA) meticillin-resistant Staphylococcus aureus (MRSA) and aims to reach a consensus regarding the harmonisation of typing methods...... health. Continuous efforts to understand the changing epidemiology of S. aureus infection in humans and animals are therefore necessary, not only for appropriate antimicrobial treatment and effective infection control but also to monitor the evolution of the species. The group made several consensus...
Dowding, J. E.
Three clinical isolates of Staphylococcus aureus resistant to gentamicin and other aminoglycosides have been examined for antibiotic modifying enzymes. The strains contain a number of these enzymes, most of them similar to those commonly found in aminoglycoside-resistant gram-negative strains. All three strains (and a transductant derived from one of them) contain two enzymes mediating gentamicin resistance, an aminoglycoside 6′-N-acetyltransferase and a novel enzyme, gentamicin phosphotransferase. PMID:836013
Benda, P; Vyletĕlová, M
In the years 1993-1994 the occurrence of Staphylococcus aureus was investigated in bulk milk samples in the area where a Baby Food Factory at Zábreh in Moravia is located, and in Bruntál, Zlín and Policka districts. Evaluation of the results was based on ECC Directive 92/46, while the dynamics of S. aureus presence was followed for the whole period of observation as well as in the particular seasons. A total of 4,485 samples was processed. Out of these, 50.7% contained less than 100 CFU/ml of S. aureus, 41.4% contained 100-500 CFU/ml, 6.73% 500-2,000 CFU/ml and 1.14% contained more than 2,000 CFU/ml (Fig. 1). The samples were divided into three categories: private new-established farms, cooperative and State-owned enterprises in the area of the Zábĕh Factory and others (Zlín, Bruntál and Policka districts). There were highly significant differences in the content of staphylococci (P = 0.01%) between the three categories of samples. Ninety-eight percent of samples from private farms, 96% samples from the Zábreh Factory area and 85% of the other samples comply with the regulation EEC 92/64 (Tab. I) for raw cow's milk for the manufacture of products "made with raw milk" whose manufacturing process does not involve any heat treatment (Fig. 2). The occurrence of S. aureus in the Zábreh Factory area shows an expressive seasonal dynamics (P = 0.005%) with maximum values in winter months (December-March) and minimum values in summer months (July-October)-Fig. 3. The same relationship can be seen on more extensive data files for the particular producers (Fig. 4).(ABSTRACT TRUNCATED AT 250 WORDS)
Lin, Yan; Liu, Yan; Luo, Yan-Ping; Liu, Chang-Ting
To analyze the change in drug resistance of Staphylococcus aureus (SAU) in the PLA general hospital from January 2008 to December 2012, and to provide solid evidence to support the rational use of antibiotics for clinical applications. The SAU strains isolated from clinical samples in the hospital were collected and subjected to the Kirby-Bauer disk diffusion test. The results were assessed based on the 2002 American National Committee for Clinical Laboratory Standards (NCCLS) guidelines. SAU strains were mainly isolated from sputum, urine, blood and wound excreta and distributed in penology, neurology wards, orthopedics and surgery ICU wards. Except for glycopeptide drugs, methicillin-resistant Staphylococcus aureus (MRSA) had a higher drug resistance rate than those of the other drugs and had significantly more resistance than methicillin-sensitive Staphylococcus aureus (MSSA) (P resistance, we discovered a gradual increase in drug resistance to fourteen test drugs during the last five years. Drug resistance rate of SAU stayed at a higher level over the last five years; moreover, the detection ratio of MRSA keeps rising year by year. It is crucial for physicians to use antibiotics rationally and monitor the change in drug resistance in a dynamic way.
Parker, Dane; Prince, Alice
Staphylococcus aureus is a common human pathogen highly evolved as both a component of the commensal flora and as a major cause of invasive infection. Severe respiratory infection due to staphylococci has been increasing due to the prevalence of more virulent USA300 CA-MRSA strains in the general population. The ability of S. aureus to adapt to the milieu of the respiratory tract has facilitated its emergence as a respiratory pathogen. Its metabolic versatility, the ability to scavenge iron, coordinate gene expression, and the horizontal acquisition of useful genetic elements have all contributed to its success as a component of the respiratory flora, in hospitalized patients, as a complication of influenza and in normal hosts. The expression of surface adhesins facilitates its persistence in the airways. In addition, the highly sophisticated interactions of the multiple S. aureus virulence factors, particularly the α-hemolysin and protein A, with diverse immune effectors in the lung such as ADAM10, TNFR1, EGFR, immunoglobulin, and complement all contribute to the pathogenesis of staphylococcal pneumonia. PMID:22037948
Flayhart, Diane; Lema, Clara; Borek, Anita; Carroll, Karen C
Screening for Staphylococcus aureus has become routine in certain patient populations. This study is the first clinical evaluation of the BBL CHROMagar Staph aureus agar (CSA) medium (BD Diagnostics, Sparks, Md.) for detection of S. aureus in nasal surveillance cultures and in respiratory samples from cystic fibrosis (CF) patients. S. aureus colonies appear mauve on CSA. Other organisms are inhibited or produce a distinctly different colony color. S. aureus was identified from all media by slide coagulase, exogenous DNase, and mannitol fermentation assays. Susceptibility testing was performed using the agar dilution method. A total of 679 samples were evaluated. All samples were inoculated onto CSA. Nasal surveillance cultures were inoculated onto sheep blood agar (SBA) (BD Diagnostics), and samples from CF patients were inoculated onto mannitol salt agar (MSA) (BD Diagnostics). Of the 679 samples cultured, 200 organisms produced a mauve color on CSA (suspicious for S. aureus) and 180 were positive for S. aureus on SBA or MSA. Of 200 CSA-positive samples 191 were identified as S. aureus. Nine mauve colonies were slide coagulase negative and were subsequently identified as Staphylococcus lugdunensis (one), Staphylococcus epidermidis (three), Staphylococcus haemolyticus (one), and Corynebacterium species (four). CSA improved the ability to detect S. aureus by recovering 12 S. aureus isolates missed by conventional media. Of the 192 S. aureus isolates recovered, 122 were methicillin susceptible and 70 were methicillin resistant. Overall, the sensitivity and specificity of CSA in this study were 99.5 and 98%, respectively. There was no difference in the performance of the slide coagulase test or in susceptibility testing performed on S. aureus recovered from CSA compared to SBA or MSA. Our data support the use of CSA in place of standard culture media for detection of S. aureus in heavily contaminated respiratory samples.
Kim, Min-Ho; Yamayoshi, Itsukyo; Mathew, Steven; Liln, Hubert; Nayfach, Joseph; Simon, Scott I.
The incidence of wound infections that do not adequately respond to standard-of-care antimicrobial treatment has been increasing. To address this challenge, a novel antimicrobial magnetic thermotherapy platform has been developed in which a high-amplitude, high-frequency, alternating magnetic field (AMF) is used to rapidly heat magnetic nanoparticles that are bound to Staphylococcus aureus (S. aureus). The antimicrobial efficacy of this platform was evaluated in the treatment of both an in vitro culture model of S. aureus biofilm and a mouse model of cutaneous S. aureus infection. We demonstrated that an antibody-targeted magnetic nanoparticle bound to S. aureus was effective at thermally inactivating S. aureus and achieving accelerated wound healing without causing tissue injury. PMID:23149904
Idrissa Diawara; Khadija Bekhti; Driss Elhabchi; Rachid Saile; Naima Elmdaghri; Mohammed Timinouni; Mohamed Elazhari
Background and objectives Staphylococcus aureus (S. aureus) nasal carriage may be responsible for some serious infections in hemodialyzed patients. The main target of this study was to estimate the prevalence of S. aureus nasal carriage in hemodialysis outpatients and medical staff in hemodialysis centers specifically in Fez region. The second target is to identify the risks of colonization, resistance pattern of isolates and their virulence toxin genes. Patients and Methods Nasal swab specim...
Astrup, Lærke Boye; Agerholm, Jørgen Steen; Nielsen, Ole Lerberg
A PORCINE MODEL OF HAEMATOGENOUS BRAIN INFECTION WITH STAPHYLOCOCCUS AUREUS Astrup Lærke1, Agerholm Jørgen1, Nielsen Ole1, Jensen Henrik1, Leifsson Páll1, Iburg Tine2. 1: Faculty of Health and Medical Sciences, University of Copenhagen, Denmark firstname.lastname@example.org 2: National Veterinary Institute......, Uppsala, Sweden Introduction Staphylococcus aureus (S.aureus) is a common cause of sepsis and brain abscesses in man and a frequent cause of porcine pyaemia. Here we present a porcine model of haematogenous S. aureus-induced brain infection. Materials and Methods Four pigs had two intravenous catheters...
Singh, Rachna; Ray, Pallab; Das, Anindita; Sharma, Meera
This study was carried out to elucidate the role of reduced antibiotic penetration in the resistance of Staphylococcus aureus and Staphylococcus epidermidis biofilms to different antibiotics. The biofilms...
A. Luijendijk (Ad); A.F. van Belkum (Alex); J.A.J.W. Kluytmans (Jan); H.A. Verbrugh (Henri)
textabstractFive different laboratory tests for the identification of Staphylococcus aureus were compared. Analyses of 271 presumptive S. aureus strains, supplemented with 59 well-defined methicillin-resistant S. aureus (MRSA) isolates, were performed. Only the
Croes, Sander; Deurenberg, Ruud H; Boumans, Marie-Louise L; Beisser, Patrick S; Neef, Cees; Stobberingh, Ellen E
BACKGROUND: Since bacteria embedded in biofilms are far more difficult to eradicate than planktonic infections, it would be useful to know whether certain Staphylococcus aureus lineages are especially involved in strong biofilm formation. For this reason, in vitro biofilm formation of 228 clinical
Full Text Available Introduction: Methicillin resistant Staphylococcus aureus (MRSA has emerged as a nosocomial pathogen of major worldwide importance and is an increasingly frequent cause of community-acquired infections. In this study, different risk factors and MRSA resistance pattern were investigated. Methods: In a 24 months period, all of the patients who were confined to bed in the surgery ward were included in the study. Then they were assessed to find out as if they had MRSA infection when hospitalized and once when they were discharged. Almost 48 h after admission, when patients were discharged, social and medical histories were acquired. Acquired samples were examined. Results: During the present study of 475 patients, 108 patients (22.8% had S. aureus. About frequency of antibiotic resistance among collected S. aureus colonies, erythromycin resistance, was the most frequent antibiotic resistance, also resistance to vancomycin was 0.4% that was the least. Only hospitalization duration had statistically significant correlation with antibiotic resistance, also resistance to erythromycin had statistically significant relation with history of surgery and alcohol consumption. Of all 34 MRSA species, 22 (64.7% samples were resistant to erythromycin, 17 (50.0% resistant to cefoxitin, 5 (14.7% resistant to mupirocin, 1 (2.9% resistant to vancomycin and 1 (2.9% resistant to linezolid. Conclusion: The results of the current study show that among hospitalized patients, there is resistance against methicillin. Since based on results of the study there is resistance against oxacillin and erythromycin in most cases, administering appropriate antibiotics have an important role in minimizing the resistance burden among bacterial species.
Full Text Available Curcumin, a natural polyphenolic flavonoid extracted from the rhizome of Curcuma longa L., was shown to possess superior potency to resensitize methicillin-resistant Staphylococcus aureus (MRSA to antibiotics. Previous studies have shown the synergistic activity of curcumin with β-lactam and quinolone antibiotics. Further, to understand the anti-MRSA mechanism of curcumin, we investigated the potentiated effect of curcumin by its interaction in diverse conditions. The mechanism of anti-MRSA action of curcumin was analyzed by the viability assay in the presence of detergents, ATPase inhibitors and peptidoglycan (PGN from S. aureus, and the PBP2a protein level was analyzed by western blotting. The morphological changes in the curcumin-treated MRSA strains were investigated by transmission electron microscopy (TEM. We analyzed increased susceptibility to MRSA isolates in the presence of curcumin. The optical densities at 600 nm (OD600 of the suspensions treated with the combinations of curcumin with triton X-100 and Tris were reduced to 63% and 59%, respectively, compared to curcumin without treatment. N,N'-dicyclohexylcarbodiimide (DCCD and sodium azide (NaN3 were reduced to 94% and 55%, respectively. When peptidoglycan (PGN from S. aureus was combined with curcumin, PGN (0–125 μg/mL gradually blocked the antibacterial activity of curcumin (125 μg/mL; however, at a concentration of 125 µg/mL PGN, it did not completely block curcumin. Curcumin has a significant effect on the protein level of PBP2a. The TEM images of MRSA showed damage of the cell wall, disruption of the cytoplasmic contents, broken cell membrane and cell lysis after the treatment of curcumin. These data indicate a remarkable antibacterial effect of curcumin, with membrane permeability enhancers and ATPase inhibitors, and curcumin did not directly bind to PGN on the cell wall. Further, the antimicrobial action of curcumin involved in the PBP2a-mediated resistance mechanism was
Vemula, Harika; Ayon, Navid J; Gutheil, William G
Intracellular cytoplasmic peptidoglycan (PG) intermediate levels were determined in Staphylococcus aureus during log-phase growth in enriched media. Levels of UDP-linked intermediates were quantitatively determined using ion pairing LC-MS/MS in negative mode, and amine intermediates were quantitatively determined stereospecifically as their Marfey's reagent derivatives in positive mode. Levels of UDP-linked intermediates in S. aureus varied from 1.4 μM for UDP-GlcNAc-Enolpyruvyate to 1200 μM for UDP-MurNAc. Levels of amine intermediates (L-Ala, D-Ala, D-Ala-D-Ala, L-Glu, D-Glu, and L-Lys) varied over a range of from 860 μM for D-Ala-D-Ala to 30-260 mM for the others. Total PG was determined from the D-Glu content of isolated PG, and used to estimate the rate of PG synthesis (in terms of cytoplasmic metabolite flux) as 690 μM/min. The total UDP-linked intermediates pool (2490 μM) is therefore sufficient to sustain growth for 3.6 min. Comparison of UDP-linked metabolite levels with published pathway enzyme characteristics demonstrates that enzymes on the UDP-branch range from >80% saturation for MurA, Z, and C, to <5% saturation for MurB. Metabolite levels were compared with literature values for Escherichia coli, with the major difference in UDP-intermediates being the level of UDP-MurNAc, which was high in S. aureus (1200 μM) and low in E. coli (45 μM). Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.
Nishimasu, Hiroshi; Cong, Le; Yan, Winston X.; Ran, F. Ann; Zetsche, Bernd; Li, Yinqing; Kurabayashi, Arisa; Ishitani, Ryuichiro; Zhang, Feng; Nureki, Osamu
The RNA-guided DNA endonuclease Cas9 cleaves double-stranded DNA targets with a protospacer adjacent motif (PAM) and complementarity to the guide RNA. Recently, we harnessed Staphylococcus aureus Cas9 (SaCas9), which is significantly smaller than Streptococcus pyogenes Cas9 (SpCas9), to facilitate efficient in vivo genome editing. Here, we report the crystal structures of SaCas9 in complex with a single guide RNA (sgRNA) and its double-stranded DNA targets, containing the 5′-TTGAAT-3′ PAM and...
Dalbøge, Christina Schjellerup; Pressler, Tacjana; Høiby, Niels
Staphylococcus aureus is an important pathogen in CF. Centre prevalence of intermittent colonization and chronic S. aureus infections and the effectiveness of an anti-S. aureus eradication strategy was assessed.......Staphylococcus aureus is an important pathogen in CF. Centre prevalence of intermittent colonization and chronic S. aureus infections and the effectiveness of an anti-S. aureus eradication strategy was assessed....
Weinstein Robert A
Full Text Available Abstract Background When Staphylococcus aureus is isolated in urine, it is thought to usually represent hematogenous spread. Because such spread might have special clinical significance, we evaluated predictors and outcomes of S. aureus bacteriuria among patients with S. aureus bacteremia. Methods A case-control study was performed at John H. Stroger Jr. Hospital of Cook County among adult inpatients during January 2002-December 2006. Cases and controls had positive and negative urine cultures, respectively, for S. aureus, within 72 hours of positive blood culture for S. aureus. Controls were sampled randomly in a 1:4 ratio. Univariate and multivariable logistic regression analyses were done. Results Overall, 59% of patients were African-American, 12% died, 56% of infections had community-onset infections, and 58% were infected with methicillin-susceptible S. aureus (MSSA. Among 61 cases and 247 controls, predictors of S. aureus bacteriuria on multivariate analysis were urological surgery (OR = 3.4, p = 0.06 and genitourinary infection (OR = 9.2, p = 0.002. Among patients who died, there were significantly more patients with bacteriuria than among patients who survived (39% vs. 17%; p = 0.002. In multiple Cox regression analysis, death risks in bacteremic patients were bacteriuria (hazard ratio 2.9, CI 1.4-5.9, p = 0.004, bladder catheter use (2.0, 1.0-4.0, p = 0.06, and Charlson score (1.1, 1.1-1.3, p = 0.02. Neither length of stay nor methicillin-resistant Staphylococcus aureus (MRSA infection was a predictor of S. aureus bacteriuria or death. Conclusions Among patients with S. aureus bacteremia, those with S. aureus bacteriuria had 3-fold higher mortality than those without bacteriuria, even after adjustment for comorbidities. Bacteriuria may identify patients with more severe bacteremia, who are at risk of worse outcomes.
Choi, Chong Seng; Yin, Chow Suet; Bakar, Afra Abu; Sakewi, Zamberi; Naing, Nyi Nyi; Jamal, Farida; Othman, Norlijah
Data on the carriage rate and antibiotic sensitivity pattern of Staphylococcus aureus strains prevalent in the community are not available for many developing countries including Malaysia. To estimate the extent of community S. aureus transmission, in particular methicillin-resistant S. aureus (MRSA), the prevalence of S. aureus nasal colonization in a population of healthy adults was determined. Factors associated with S. aureus nasal carriage and antibiotic sensitivity patterns of the isolates were also analyzed. A cross-sectional study involving 346 adults was conducted. Nasal swabs were examined for the presence of S. aureus. Epidemiological information concerning risk factors for nasal carriage was also obtained. Antibiotic susceptibility testing was performed using the disk diffusion method according to the National Committee for Clinical Laboratory Standards guidelines. MRSA strains isolated were further subjected to pulse-field gel electrophoresis analysis. The prevalence of S. aureus nasal carriage was 23.4%. The findings also revealed that ex-smokers (95% confidence interval [CI] 1.08-6.32, p=0.033) and oral contraceptive users (95% CI 1.12-21.67, p=0.035) were more likely to harbor S. aureus. One person was colonized with MRSA, which was different from the hospital strain. MRSA nasal colonization was found to be low outside of the health care environment. Smokers and oral contraceptive users have high nasal carrier rates.
Isolates of Staphylococcus aureus from children aged 5 years and below with sporadic diarrhoea were tested for their ability to produce beta-lactamase enzyme. Of the 95 isolates tested 79 (83.2%) were beta-lactamase-producing strains. The study confirms that majority of clinical isolates of S. aureus from diarrhoeic ...
Goldmann, Oliver; Medina, Eva
Staphylococcus aureus poses a significant public-health problem. Infection caused by S. aureus can manifest as acute or long-lasting persistent diseases that are often refractory to antibiotic and are associated with significant morbidity and mortality. To develop more effective strategies for preventing or treating these infections, it is crucial to understand why the immune response is incapable to eradicate the bacterium. When S. aureus first infect the host, there is a robust activation of the host innate immune responses. Generally, S. aureus can survive this initial interaction due to the expression of a wide array of virulence factors that interfere with the host innate immune defenses. After this initial interaction the acquired immune response is the arm of the host defenses that will try to clear the pathogen. However, S. aureus is capable of maintaining infection in the host even in the presence of a robust antigen-specific immune response. Thus, understanding the mechanisms underlying the ability of S. aureus to escape immune surveillance by the acquired immune response will help uncover potentially important targets for the development of immune-based adjunctive therapies and more efficient vaccines. There are several lines of evidence that lead us to believe that S. aureus can directly or indirectly disable the acquired immune response. This review will discuss the different immune evasion strategies used by S. aureus to modulate the different components of the acquired immune defenses. Copyright © 2017 Elsevier GmbH. All rights reserved.
van Leeuwen, Willem B.; Snoeijers, Sandor; van der Werken-Libregts, Christel; Tuip, Anita; van der Zee, Anneke; Egberink, Diane; de Proost, Monique; Bik, Elisabeth; Lunter, Bjorn; Kluytmans, Jan; Gits, Etty; van Duyn, Inge; Heck, Max; van der Zwaluw, Kim; Wannet, Wim; Noordhoek, Gerda T.; Mulder, Sije; Renders, Nicole; Boers, Miranda; Zaat, Sebastiaan; van der Riet, Daniëlle; Kooistra, Mirjam; Talens, Adriaan; Dijkshoorn, Lenie; van der Reyden, Tanny; Veenendaal, Dick; Bakker, Nancy; Cookson, Barry; Lynch, Alisson; Witte, Wolfgang; Cuny, Christa; Blanc, Dominique; Vernez, Isabelle; Hryniewicz, Waleria; Fiett, Janusz; Struelens, Marc; Deplano, Ariane; Landegent, Jim; Verbrugh, Henri A.; van Belkum, Alex
The reproducibility of the binary typing (BT) protocol developed for epidemiological typing of Staphylococcus aureus was analyzed in a biphasic multicenter study. In a Dutch multicenter pilot study, 10 genetically unique isolates of methicillin-resistant S. aureus (MRSA) were characterized by the BT
Chang, Tianjun; Wang, Libo; Zhao, Kexu; Ge, Yu; He, Meng; Li, Gang
Staphylococcus aureus is the top common pathogen causing infections and food poisoning. Identification of S. aureus is crucial for the disease diagnosis and regulation of food hygiene. Herein, we report an aptamer-AuNPs based method for duplex identification of S. aureus. Using AuNPs as an indicator, SA23, an aptamer against S. aureus, can well identify its target from Escherichia coli, Listeria monocytogenes and Pseudomonas aeruginosa. Furthermore, we find citrate-coated AuNPs can strongly bind to S. aureus, but not bind to Salmonella enterica and Proteus mirabilis, which leads to different color changes in salt solution. This colorimetric response is capable of distinguishing S. aureus from S. enteritidis and P. mirabilis. Thus, using the aptasensor and AuNPs together, S. aureus can be accurately identified from the common pathogens. This duplex identification system is a promising platform for simple visual identification of S. aureus. Additionally, in the aptasensing process, bacteria are incubated with aptamers and then be removed before the aptamers adding to AuNPs, which may avoid the interactions between bacteria and AuNPs. This strategy can be potentially applied in principle to detect other cells by AuNPs-based aptasensors.
N.J. Verkaik (Nelianne); H.A.M. Boelens (Hélène); C.P. de Vogel (Corné); M. Tavakol (Mehri); L.G.M. Bode (Lonneke); H.A. Verbrugh (Henri); A.F. van Belkum (Alex); W.J.B. van Wamel (Willem)
textabstractExpanding knowledge on the humoral immune response in Staphylococcus aureus-infected patients is a mandatory step in the development of vaccines and immunotherapies. Here, we present novel insights into the antibody responses following S. aureus bacteremia. Fifteen bacteremic patients
pathogens that can cause mastitis, Staphylococcus aureus is probably the most lethal agent because it causes chronic and deep infection in the mammary glands that is extremely difficult to be cured. The present study was to detect some of the virulence factors in the S. aureus isolated from 360 mastitis milk samples in ...
Becker, Karsten; Schaumburg, Frieder; Fegeler, Christian; Friedrich, Alexander W.; Kock, Robin
Objectives: This prospective cohort study evaluates colonization dynamics and molecular characteristics of methicillin-susceptible and - resistant Staphylococcus aureus (MSSA/MRSA) in a German general population. Methods: Nasal swabs of 1878 non-hospitalized adults were screened for S. aureus.
Staphylococcus aureus remains an important cause of mortality, in the community and health care set-ups. S. aureus strains with genes encoding lethal toxins and culture negative sepsis augment the diagnostic challenge in resource limited settings. With a growing rate of resistance to the causative bacteria and atypical ...
Staphylococcus aureus remains one of the most common causes of bacteraemia in children. In order to evade and overcome the immune responses of its host and any antimicrobial therapies aimed at destroying it, this organism, through various mechanisms, continues to evolve. Staphylococcus aureus bacteraemia is a ...
Jelsbak, Lotte; Thomsen, Line Elnif; Ingmer, Hanne
Staphyloccous aureus is a major human pathogen capable of causing a wide spectrum of infections ranging from superficial wound infections to life-threatening endocarditis and toxic shock syndrome. Essential for S. aureus virulence is a large number of cell-surface-associated proteins and secreted...
Background: Nasal Staphylococcus aureus is a major source of community and hospital associated staphylococcal infections. This study determined the prevalence of nasal S. aureus isolates and investigated their antimicrobial resistance profile in healthy volunteers. Methods: Nasal specimens of healthy volunteers in ...
Staphylococcus aureus causes foodborne diseases if consumed in contaminated milk products. Rapid detection and characterization of foodborne pathogen S. aureus is crucial for epidemiological investigations and food safety surveillance. It is still a challenge to detect and identify bacterial pathogens quickly and ...
Staphylococcus aureus is a causative agent of acute and infectious diarrhoea. In Africa, there is no sufficient information on the virulence and the degree of factors produced by its diarrhoea-isolated strains. Clinical features and virulence factors produced by S. aureus isolated from diarrhoeal-patients admitted at the ...
Yan, Xiaomei; Yu, Xiaojie; Tao, Xiaoxia; Zhang, Jianfeng; Zhang, Binghua; Dong, Rui; Xue, Chengyu; Grundmann, Hajo; Zhang, Jianzhong
To describe the prevalence and population structure of Staphylococcus aureus bacteria that colonize pigs at slaughterhouses in northeastern China, nose swabs were collected from pigs in two slaughterhouses in Harbin, Heilongjiang Province, China in 2009.S. aureus isolates were characterized by
Purpose: To determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in apparently healthy ... Keywords: Methicillin-resistant Staphylococcus aureus, Nasal swabs, Multidrug resistance, Rational chemotherapy .... Figure 2: Antibiotic resistance profile of the MRSA isolates. Key: AM-amoxicillin ...
Staphylococcus aureus isolates were collected from anterior nares of fifty healthy adults in Zaria and their antibiotic susceptibility patterns determined. Seventy-two percent (72%) of the isolates were methicillin-resistant S. aureus, while 20% were methicillin-susceptible. The isolates were generally resistant to multiple ...
Staphylococcus aureus is a major bacterial pathogen that causes different community and hospital-acquired infections. Over time, strains of S. aureus have become resistant to different antibiotics including penicillinase-resistant penicillins. Having data on the local antimicrobial susceptibility pattern of this pathogen is ...
Jun 21, 2010 ... present study was to detect some of the virulence factors in the S. aureus isolated from 360 mastitis milk samples in ... Key words: Bovine mastitis, Staphylococcus aureus, virulence factors, polymerase chain reaction (PCR), Iran. INTRODUCTION ..... staphylococcal hemolysins. Zentralbl Bakteriol Orig A.
Amissah, Nana Ama; Chlebowicz, Monika A.; Ablordey, Anthony; Tetteh, Caitlin S.; Prah, Isaac; van der Werf, Tjip S.; Friedrich, Alex W.; van Dijl, Jan Maarten; Stienstra, Ymkje; Rossen, John W.
Buruli ulcer (BU) is a necrotizing infection of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. BU wounds may also be colonized with other microorganisms including Staphylococcus aureus. This study aimed to characterize the virulence factors of S. aureus isolated from BU patients.
and its associated risk factors in Addis Ababa City,. Ethiopia ... and wide spread livestock diseases (Mohammed Ahmed et al., 2004). Mastitis .... Legesse Garedew et al.,. Table 2: Risk factors associated with the occurrence of Staphylococcus aureus in mastitic cows. Risk factor. Total animals S. aureus positives. X2 p-value.
Dari hasil penelitian , maka dapat disimpulkan bahwa ekstrak Aloe Vera dapat menghambat pertumbuhan bakteri Stafhylococcus aureus, dan kadar hambat minimal ekstrak Aloe Vera adalah pada konsentrasi 25%. Tujuan Penelitan Ini adalah untuk mengetahui efektifitas ekstrak Aloe vera dalam menghambat pertumbuhan bakteri Stafhylococcus aureus dan daya hambat menimal, (DHM) terhadap pertumbuhan bakteri tersebut. Metode yang digunakan adalah pertumbuhan ekstrak Aloe vera, penegnceran ekstrak , pemur...
Ghanim, Nibal; Alchyib, Omrou; Morrish, Donald; Tompkins, David; Julliard, Kell; Visconti, Ernest; Hoskins, Iffath A
To estimate prevalence of rectovaginal colonization by Staphylococcus aureus among pregnant women with group B streptococcus (GBS) screening results and its association with maternal and infant outcomes. Cultures that detected both group B streptococcus (GBS) and S. aureus were obtained at > or = 35 weeks of gestation. Computerized database search and chart review determined invasive neonatal infection and maternal outcomes at the time of delivery through 6 months postpartum. A total of 6,626 GBS screening cultures met study criteria, and 769 (11.6%) GBS isolates and 67 (1.0%) S. aureus were identified. No maternal S. aureus-related outcomes were found. The rate of maternal methicillin-resistant S. aureus colonization was 0.1% (7 in 6,626). GBS-positive patients were twice as likely to be colonized with methicillin-susceptible S. aureus than GBS-negative patients. GBS-positive culture rates differed significantly by primary language: Spanish 10.0%, English 13.7%, Russian 26.9%, Cantonese 13.2%, Mandarin 11.5%, Arabic 15.9%, and other 17.8%. In our population, S. aureus colonization percentage (1.0%) was lower than the 7.5-8.2% reported by other medical centers, as was overall GBS carriage rate. S. aureus did not predispose to maternal or infant morbidity or mortality up to 6 months postpartum.
A study of carriage of Staphylococcus aureus on armpits and factors affecting it was carried out on 50 students from Community Secondary School, Oroworokwu, Port Harcourt and 50 University of Port Harcourt students. Samples were inoculated onto mannitol salt agar plates and coagulate positive S. aureus isolates were ...
Abdelhamid, Hani Nasser; Wu, Hui-Fen
Selective biosensing of Staphylococcus aureus (S. aureus) using chitosan modified quantum dots (CTS@CdS QDs) in the presence of hydrogen peroxide is reported. The method is based on the intrinsic positive catalase activity of S. aureus. CTS@CdS quantum dots provide high dispersion in aqueous media with high fluorescence emission. Staphylococcus aureus causes a selective quenching of the fluorescence emission of CTS@CdS QDs in the presence of H2O2 compared to other pathogens such as Escherichia coli and Pseudomonas aeruginosa. The intrinsic enzymatic character of S. aureus (catalase positive) offers selective and fast biosensing. The present method is highly selective for positive catalase species and requires no expensive reagents such as antibodies, aptamers or microbeads. It could be extended for other species that are positive catalase.
Josse, Jérôme; Velard, Frédéric; Gangloff, Sophie C.
Bone cells, namely osteoblasts and osteoclasts work in concert and are responsible for bone extracellular matrix formation and resorption. This homeostasis is, in part, altered during infections by Staphylococcus aureus through the induction of various responses from the osteoblasts. This includes the over-production of chemokines, cytokines and growth factors, thus suggesting a role for these cells in both innate and adaptive immunity. S. aureus decreases the activity and viability of osteoblasts, by induction of apoptosis-dependent and independent mechanisms. The tight relationship between osteoclasts and osteoblasts is also modulated by S. aureus infection. The present review provides a survey of the relevant literature discussing the important aspects of S. aureus and osteoblast interaction as well as the ability for antimicrobial peptides to kill intra-osteoblastic S. aureus, hence emphasizing the necessity for new anti-infectious therapeutics. PMID:26636047
Christiansen, Mette Theilgaard
. aureus and methicillin-resistant Staphylococcus aureus (MRSA) have been associated with hospitals, but during the past decades MRSA has emerged in the community and now a new branch of MRSA has been found in association with livestock (LA-MRSA). A specific lineage (multilocus sequence type 398 (ST398......Staphylococcus aureus is an opportunistic pathogen that colonizes the nares and skin surfaces of several animal species, including man. S. aureus can cause a wide variety of infections ranging from superficial soft tissue and skin infections to severe and deadly systemic infections. Traditionally S...... for LA-MRSA ST398 survival on porcine skin and nasal epithelium ex vivo were identified. These genes could represent targets for de-colonization, which could help prevent further spread and adaption of LA-MRSA ST398. Manuscript III describes the construction of the S. aureus VirulenceFinder database...
Qian, Qinfang; Eichelberger, Karen; Kirby, James E.
The BinaxNOW Staphylococcus aureus testing showed sensitivity, specificity, and positive and negative predicative values of 97.6%, 100%, 100%, and 98.4%, respectively, for identification of S. aureus from Bactec blood culture broth. Importantly, the test performed equally well on aerobic and anaerobic culture broth.
Full Text Available Of 259 college students in northern Taiwan surveyed, nasal carriage rate of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA was 22.4% and 1.54%, respectively and no significant difference was found between athlete students and non-athlete students. Three of four MRSA isolates belonged to sequence type 59, the endemic community clone.
Loncaric, Igor; Kübber-Heiss, Anna; Posautz, Annika; Stalder, Gabrielle L; Hoffmann, Daniel; Rosengarten, Renate; Walzer, Chris
A recently identified mecA homologue, mecC, in methicillin-resistant Staphylococcus aureus (MRSA) has been isolated from humans and different animal hosts. The aim of this study was to determine antimicrobial resistance and provide molecular characterization of MRSA and methicillin-resistant non-Staphylococcus aureus staphylococci (MRnSA) isolated from wildlife that carried the gene mecC. Five S. aureus and one coagulase-negative Staphylococcus isolate displaying phenotypic oxacillin resistance, but not recognized with conventional PCR for mecA, were further characterized by a polyphasic approach. The presence of mecC in all isolates was determined using specific PCR. PCR targeting Panton-Valentine leucocidin (PVL) genes of MRSA was performed. MRSA isolates were genotyped by spa typing and multilocus sequence typing. All isolates were genotyped by staphylococcal cassette chromosome mec (SCCmec) typing. 16S rDNA sequence analysis for MRnSA identification was performed. Antimicrobial susceptibility testing was performed for all isolates. All five MRSA isolates contained the mecC gene, were PVL negative, carried SCCmec type XI and belonged to ST130 (where ST stands for sequence type), with spa types t843, t10513 or t3256, or to ST2620, with spa type t4335. The MRnSA isolate, most closely related to Staphylococcus stepanovicii, carried mecA and blaZ genes related to SCCmec XI. MRSA isolates exhibited resistance to the β-lactams only. The MRSA isolates described in this study represent the first detection of mecC-positive MRSA in a European otter (Lutra lutra) and a European brown hare (Lepus europaeus). The MRnSA isolate represents the first isolation of MRnSA from a Eurasian lynx (Lynx lynx).
Arduino, Jean Marie; Kaye, Keith S; Reed, Shelby D; Peter, Senaka A; Sexton, Daniel J; Chen, Luke F; Hardy, N Chantelle; Tong, Steven Yc; Smugar, Steven S; Fowler, Vance G; Anderson, Deverick J
Staphylococcus aureus is the most common and most important pathogen following knee and hip arthroplasty procedures. Understanding the epidemiology of invasive S. aureus infections is important to quantify this serious complication. This nested retrospective cohort analysis included adult patients who had undergone insertion of knee or hip prostheses with clean or clean-contaminated wound class at 11 hospitals between 2003-2006. Invasive S. aureus infections, non-superficial incisional surgical site infections (SSIs) and blood stream infections (BSIs), were prospectively identified following each procedure. Prevalence rates, per 100 procedures, were estimated. 13,719 prosthetic knee (62%) and hip (38%) insertion procedures were performed. Of 92 invasive S. aureus infections identified, SSIs were more common (80%) than SSI and BSI (10%) or BSI alone (10%). The rate of invasive S. aureus infection/100 procedures was 0.57 [95% CI: 0.43-0.73] for knee insertion and 0.83 [95% CI: 0.61-1.08] for hip insertion. More than half (53%) were methicillin-resistant. Median time-to-onset of infection was 34 and 26 days for knee and hip insertion, respectively. Infection was associated with higher National Healthcare Safety Network risk index (p ≤ 0.0001). Post-operative invasive S. aureus infections were rare, but difficult-to-treat methicillin-resistant infections were relatively common. Optimizing preventative efforts may greatly reduce the healthcare burden associated with S. aureus infections.
Fermin E. Guerra
Full Text Available Neutrophils are the most abundant leukocytes in human blood and the first line of defense after bacteria have breached the epithelial barriers. After migration to a site of infection, neutrophils engage and expose invading microorganisms to antimicrobial peptides and proteins, as well as reactive oxygen species, as part of their bactericidal arsenal. Ideally, neutrophils ingest bacteria to prevent damage to surrounding cells and tissues, kill invading microorganisms with antimicrobial mechanisms, undergo programmed cell death to minimize inflammation, and are cleared away by macrophages. Staphylococcus aureus (S. aureus is a prevalent Gram-positive bacterium that is a common commensal and causes a wide range of diseases from skin infections to endocarditis. Since its discovery, S. aureus has been a formidable neutrophil foe that has challenged the efficacy of this professional assassin. Indeed, proper clearance of S. aureus by neutrophils is essential to positive infection outcome, and S. aureus has developed mechanisms to evade neutrophil killing. Herein, we will review mechanisms used by S. aureus to modulate and evade neutrophil bactericidal mechanisms including priming, activation, chemotaxis, production of reactive oxygen species, and resolution of infection. We will also highlight how S. aureus uses sensory/regulatory systems to tailor production of virulence factors specifically to the triggering signal, e.g., neutrophils and defensins. To conclude, we will provide an overview of therapeutic approaches that may potentially enhance neutrophil antimicrobial functions.
Miguel Ángel Ortiz-Gila
Full Text Available Existe un gran ecosistema microbiano en la cavidad oral donde Staphylococcus aureus ( S. aureus se puede encontrar, causando patologías orales tales como quelitis angular, las paperas y la mucositis estafilocócica. Estas enfermedades producidas por S. aureus en la cavidad oral son consecuencia de los factores de virulencia, toxinas y multiresistencia a los antibióticos, lo que contribuye a la infección. La colonización en la cavidad oral por S. aureus en pacientes sanos es de 24% a 36%. Sin embargo, la incidencia aumenta a 48% en pacientes con prótesis debido a la formación de biofilms en la superficie de las dentaduras postizas. Actualmente, no existe ningún tratamiento para infecciones orales sin el uso de antibióticos. Investigaciones recientes indican que las nanopartículas de plata (AgNPs son un material o estrategia para eliminar S. aureus debido a su efecto antibacteriano. Sin embargo, el mecanismo del efecto inhibidor de los iones de Ag sobre S. aureus es sólo parcialmente conocida y muy poco se ha informado. Por lo tanto, el propósito de la presente revisión sistemática es determinar las estrategias y retos de la utilización de biomateriales antimicrobianos con AgNPs frente a las infecciones orales de S. aureus.
Barbero Allende, José M; Romanyk Cabrera, Juan; Montero Ruiz, Eduardo; Vallés Purroy, Alfonso; Melgar Molero, Virginia; Agudo López, Rosa; Gete García, Luis; López Álvarez, Joaquín
Prosthetic joint infection (PJI) is a complication with serious repercussions and its main cause is Staphylococcus aureus. The purpose of this study is to determine whether decolonization of S.aureus carriers helps to reduce the incidence of PJI by S.aureus. An S.aureus screening test was performed on nasal carriers in patients undergoing knee or hip arthroplasty between January and December 2011. Patients with a positive test were treated with intranasal mupirocin and chlorhexidine soap 5 days. The incidence of PJI was compared with patients undergoing the same surgery between January and December 2010. A total of 393 joint replacements were performed in 391 patients from the control group, with 416 joint replacements being performed in the intervention group. Colonization study was performed in 382 patients (91.8%), of which 102 were positive (26.7%) and treated. There was 2 PJI due S.aureus compared with 9 in the control group (0.5% vs 2.3%, odds ratio [OR]: 0.2, 95% confidence interval [CI]: 0.4 to 2.3, P=.04). In our study, the detection of colonization and eradication of S.aureus carriers achieved a significant decrease in PJI due to S.aureus compared to a historical group. Copyright © 2013 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.
Laupland, K.B.; Lyytikäinen, O.; Søgaard, Mette
Clin Microbiol Infect ABSTRACT: Although the epidemiology of Staphylococcus aureus bloodstream infection (BSI) has been changing, international comparisons are lacking. We sought to determine the incidence of S. aureus BSI and assess trends over time and by region. Population-based surveillance...... episodes of S. aureus BSI were identified. The overall annual incidence rate for S. aureus BSI was 26.1 per 100 000 population, and those for methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) were 24.2 and 1.9 per 100 000, respectively. Although the overall incidence...... of community-onset MSSA BSI (15.0 per 100 000) was relatively similar across regions, the incidence rates of hospital-onset MSSA (9.2 per 100 000), community-onset MRSA (1.0 per 100 000) and hospital-onset MRSA (0.8 per 100 000) BSI varied substantially. Whereas the overall incidence of S. aureus BSI did...
Guerra, Fermin E.; Borgogna, Timothy R.; Patel, Delisha M.; Sward, Eli W.; Voyich, Jovanka M.
Neutrophils are the most abundant leukocytes in human blood and the first line of defense after bacteria have breached the epithelial barriers. After migration to a site of infection, neutrophils engage and expose invading microorganisms to antimicrobial peptides and proteins, as well as reactive oxygen species, as part of their bactericidal arsenal. Ideally, neutrophils ingest bacteria to prevent damage to surrounding cells and tissues, kill invading microorganisms with antimicrobial mechanisms, undergo programmed cell death to minimize inflammation, and are cleared away by macrophages. Staphylococcus aureus (S. aureus) is a prevalent Gram-positive bacterium that is a common commensal and causes a wide range of diseases from skin infections to endocarditis. Since its discovery, S. aureus has been a formidable neutrophil foe that has challenged the efficacy of this professional assassin. Indeed, proper clearance of S. aureus by neutrophils is essential to positive infection outcome, and S. aureus has developed mechanisms to evade neutrophil killing. Herein, we will review mechanisms used by S. aureus to modulate and evade neutrophil bactericidal mechanisms including priming, activation, chemotaxis, production of reactive oxygen species, and resolution of infection. We will also highlight how S. aureus uses sensory/regulatory systems to tailor production of virulence factors specifically to the triggering signal, e.g., neutrophils and defensins. To conclude, we will provide an overview of therapeutic approaches that may potentially enhance neutrophil antimicrobial functions. PMID:28713774
NAVAL MEDICAL RESEARCH UNIT SAN ANTONIO Disruption of Methicillin-resistant Staphylococcus aureus Biofilms with Enzymatic...Methicillin-resistant Staphylococcus aureus MSSA Methicillin-sensitive Staphylococcus aureus OD Optical density PBS Phosphate-buffered saline SEM... Staphylococcus aureus biofilm model that mimics wound-like conditions and employ this model to evaluate the anti-biofilm activity of four enzymatic compounds
Asgeirsson, Hilmir; Kristjansson, Mar; Kristinsson, Karl G; Gudlaugsson, Olafur
To evaluate the clinical significance of Staphylococcus aureus bacteriuria (SABU) in adults with S. aureus bacteraemia (SAB). All individuals ≥18 years old diagnosed with SAB in Iceland between December 1st 2003 and November 30th 2008 were retrospectively identified. Data was collected from medical records. Concomitant SABU was defined as growth of S. aureus in a urine sample taken within 24 h of the index blood culture. SABU was seen in 27 of 166 (16.3%) SAB patients having urine cultured before administration of antibiotics, but after excluding those with SAB of urinary tract origin SABU was seen in 16 of 152 (10.5%). In this latter cohort SABU was independently associated with having endocarditis (RR 6.68; 95% CI 1.53-17.3) and admission to intensive-care unit (RR 2.84; 95% CI 1.25-4.44), while for having complicated SAB the RR was 1.56 (95% CI 0.96-1.80). No correlation was seen with mortality or relapse rates. SABU appears to be secondary to SAB in some cases while it is the primary infection causing SAB in others. In patients with SAB of non-urinary tract origin SABU should probably be regarded as distant haematogenous seeding and a marker of deep tissue dissemination, thus affecting general management and treatment duration. Copyright © 2011 The British Infection Association. Published by Elsevier Ltd. All rights reserved.
Vallejo, Jesus G; Cain, Alexandra N; Mason, Edward O; Kaplan, Sheldon L; Hultén, Kristina G
Central nervous system (CNS) infections caused by Staphylococcus aureus are uncommon in pediatric patients. We review the epidemiology, clinical features and treatment in 68 patients with a S. aureus CNS infection evaluated at Texas Children's Hospital. Cases of CNS infection in children with positive cerebrospinal fluid cultures or spinal epidural abscess (SEA) for S. aureus at Texas Children's Hospital from 2001 to 2013 were reviewed. Seventy cases of S. aureus CNS infection occurred in 68 patients. Forty-nine cases (70%) were secondary to a CNS device, 5 (7.1%) were postoperative meningitis, 9 (12.8%) were hematogenous meningitis and 7 (10%) were SEAs. Forty-seven (67.2%) were caused by methicillin-sensitive S. aureus (MSSA) and 23 (32.8%) by methicillin-resistant S. aureus (MRSA). Community-acquired infections were more often caused by MRSA that was clone USA300/pvl. Most patients were treated with nafcillin (MSSA) or vancomycin (MRSA) with or without rifampin. Among patients with MRSA infection, 50% had a serum vancomycin trough obtained with the median level being 10.6 μg/mL (range: 5.4-15.7 μg/mL). Only 1 death was associated with S. aureus infection. The epidemiology of invasive of S. aureus infections continues to evolve with MSSA accounting for most of the infections in this series. The majority of cases were associated with neurosurgical procedures; however, hematogenous S. aureus meningitis and SEA occurred as community-acquired infections in patients without predisposing factors. Patients with MRSA CNS infections had a favorable response to vancomycin, but the beneficial effect of combination therapy or targeting vancomycin trough concentrations of 15-20 μg/mL remains unclear.
Connolly, B; Johnstone, F; Gerlinger, T; Puttler, E
Methicillin-resistant Staphylococcus aureus is an increasingly prevalent nosocomial pathogen that presents therapeutic challenges. We report an incidence of methicillin-resistant S aureus in a felon. The biochemical and clinical characteristics of methicillin-resistant S aureus are reviewed. The alarming increase of this organism in various types of infections demands the attention of all surgeons and emphasizes the importance of early surgical drainage and culture of pus in all cases of infection. (J Hand Surg 2000; 25A:173-175. Copyright 2000 by the American Society for Surgery of the Hand.).
Boss, R; Cosandey, A; Luini, M; Artursson, K; Bardiau, M; Breitenwieser, F; Hehenberger, E; Lam, Th; Mansfeld, M; Michel, A; Mösslacher, G; Naskova, J; Nelson, S; Podpečan, O; Raemy, A; Ryan, E; Salat, O; Zangerl, P; Steiner, A; Graber, H U
Staphylococcus aureus is globally one of the most important pathogens causing contagious mastitis in cattle. Previous studies using ribosomal spacer (RS)-PCR, however, demonstrated in Swiss cows that Staph. aureus isolated from bovine intramammary infections are genetically heterogeneous, with Staph. aureus genotype B (GTB) and GTC being the most prominent genotypes. Furthermore, Staph. aureus GTB was found to be contagious, whereas Staph. aureus GTC and all the remaining genotypes were involved in individual cow disease. In addition to RS-PCR, other methods for subtyping Staph. aureus are known, including spa typing and multilocus sequence typing (MLST). They are based on sequencing the spa and various housekeeping genes, respectively. The aim of the present study was to compare the 3 analytic methods using 456 strains of Staph. aureus isolated from milk of bovine intramammary infections and bulk tanks obtained from 12 European countries. Furthermore, the phylogeny of animal Staph. aureus was inferred and the zoonotic transfer of Staph. aureus between cattle and humans was studied. The analyzed strains could be grouped into 6 genotypic clusters, with CLB, CLC, and CLR being the most prominent ones. Comparing the 3 subtyping methods, RS-PCR showed the highest resolution, followed by spa typing and MLST. We found associations among the methods but in many cases they were unsatisfactory except for CLB and CLC. Cluster CLB was positive for clonal complex (CC)8 in 99% of the cases and typically positive for t2953; it is the cattle-adapted form of CC8. Cluster CLC was always positive for tbl 2645 and typically positive for CC705. For CLR and the remaining subtypes, links among the 3 methods were generally poor. Bovine Staph. aureus is highly clonal and a few clones predominate. Animal Staph. aureus always evolve from human strains, such that every human strain may be the ancestor of a novel animal-adapted strain. The zoonotic transfer of IMI- and milk-associated strains
Liu, Cindy M; Price, Lance B; Hungate, Bruce A
The human microbiome can play a key role in host susceptibility to pathogens, including in the nasal cavity, a site favored by Staphylococcus aureus. However, what determines our resident nasal microbiota-the host or the environment-and can interactions among nasal bacteria determine S. aureus...... colonization? Our study of 46 monozygotic and 43 dizygotic twin pairs revealed that nasal microbiota is an environmentally derived trait, but the host's sex and genetics significantly influence nasal bacterial density. Although specific taxa, including lactic acid bacteria, can determine S. aureus colonization...
Full Text Available Diseases caused by Staphylococcus aureus are widespread through the world in spite of developing technology. S. aureus is an important pathogen causing food intoxications besides hospital infections by its antibiotic resistant strains. Nowadays, there has been worldwide increasing concern on usage of natural products to control microorganisms. One of these natural products is essential oils. They are produced from plants especially from spices and composed of many components and volatiles. This review summarizes informative literature on essential oils and their mode of antimicrobial action. In addition, current knowledge on in vitro researches on antibacterial activity of essential oils and food applications to control S. aureus has been discussed.
Williamson, D A; Coombs, G W; Nimmo, G R
The clinical and molecular epidemiology of Staphylococcus aureus disease has changed considerably over the past two decades, particularly with the emergence and spread of community-associated methicillin-resistant S. aureus (CA-MRSA) clones. Indeed, some of the first global descriptions of CA-MRSA were from remote indigenous communities in Western Australia, and from Pacific Peoples in New Zealand. The epidemiology of S. aureus infections in the South West Pacific has several unique features, largely because of the relative geographical isolation and unique indigenous communities residing in this region. In particular, a number of distinct CA-MRSA clones circulate in Australia and New Zealand, such as sequence type (ST) 93 methicillin-resistant S. aureus (MRSA) (Queensland clone) and clonal complex 75 S. aureus (Staphylococcus argenteus) in Australia, and ST30 MRSA (Southwest Pacific clone) in New Zealand. In addition, there is a disproportionate burden of S. aureus disease in indigenous paediatric populations, particularly in remote Aboriginal communities in Australia, and in Pacific Peoples and Maori in New Zealand. In this review, we provide a contemporary overview of the clinical and molecular epidemiology of S. aureus disease in the South West Pacific region, with a particular focus on features distinct to this region. © 2014 The Authors Clinical Microbiology and Infection © 2014 European Society of Clinical Microbiology and Infectious Diseases.
Donskey Curtis J
Full Text Available Abstract Background Intestinal colonization by Staphylococcus aureus among hospitalized patients has been associated with increased risk of staphylococcal infection and could potentially contribute to transmission. We hypothesized that S. aureus intestinal colonization is associated with increased frequency of S. aureus on patients' skin and nearby environmental surfaces. Methods Selected inpatients were cultured weekly for S. aureus from stool, nares, skin (groin and axilla, and environmental surfaces (bed rail and bedside table. Investigator's hands were cultured after contacting the patients' skin and the environmental surfaces. Results Of 71 subjects, 32 (45.1% had negative nares and stool cultures, 23 (32.4% had positive nares and stool cultures, 13 (18.3% were nares carriers only, and 3 (4.2% were stool carriers only. Of the 39 patients with S. aureus carriage, 30 (76.9% had methicillin-resistant isolates. In comparison to nares colonization only, nares and intestinal colonization was associated with increased frequency of positive skin cultures (41% versus 77%; p = 0.001 and trends toward increased environmental contamination (45% versus 62%; p = 0.188 and acquisition on investigator's hands (36% versus 60%; p = 0.057. Patients with negative nares and stool cultures had low frequency of S. aureus on skin and the environment (4.8% and 11.3%, respectively. Conclusion We found that hospitalized patients with S. aureus nares and/or stool carriage frequently had S. aureus on their skin and on nearby environmental surfaces. S. aureus intestinal colonization was associated with increased frequency of positive skin cultures, which could potentially facilitate staphylococcal infections and nosocomial transmission.
Ben Zakour, Nouri L; Sturdevant, Daniel E.; Even, Sergine; Guinane, Caitriona M.; Barbey, Corinne; Alves, Priscila D.; Cochet, Marie-Françoise; Gautier, Michel; Otto, Michael; Fitzgerald, J. Ross; Le Loir, Yves
Staphylococcus aureus causes disease in humans and a wide array of animals. Of note, S. aureus mastitis of ruminants, including cows, sheep, and goats, results in major economic losses worldwide. Extensive variation in genome content exists among S. aureus pathogenic clones. However, the genomic variation among S. aureus strains infecting different animal species has not been well examined. To investigate variation in the genome content of human and ruminant S. aureus, we carried out whole-ge...
Full Text Available Due to the emergence of Staphylococcus aureus with reduced vancomycin susceptibility, newer antibiotics, including daptomycin, have been used to treat methicillin-resistant S aureus infections. Daptomycin is a cyclic lipopeptide that is approved to treat S aureus bacteremia and right-sided endocarditis, and reports of S aureus with reduced susceptibility to daptomycin are infrequent. To our knowledge, the present report describes the first Canadian case of daptomycin-nonsusceptible, vancomycin-intermediate S aureus infection.
, however, the prevalence of phage group III and α-haemolytic strains of S. aureus calls for concern since these groups have frequently been implicated in food borne diseases. Effective hazard analysis critical control point (HACCP) evaluation ...
Specimens were collected for culture and sensitivity before commencement of antibiotic therapy. The major isolated organism was Staphylococcus aureus. Others were Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris Proteus rettgerri, Alkaligenes faecalis, Acinetobacter calcoaceticus ...
Tight regulation of genes upon changing environments is important in establishing and maintaining infections by pathogens. In Staphylococcus aureus, gene expression and particularly controlled expression of various groups of genes dependent on growth and environmental conditions is essential for
W.B. van Leeuwen (Willem); C. Jay (Corinne); S.V. Snijders (Susan); N. Durin (Nathalia); B. Lacroix (Bruno); H.A. Verbrugh (Henri); M.C. Enright (Mark); A. Troesch (Alain); A.F. van Belkum (Alex)
textabstractA newly developed oligonucleotide array suited for multilocus sequence typing (MLST) of Staphylococcus aureus strains was analyzed with two strain collections in a two-center study. MLST allele identification for the first strain collection fully agreed with
Sensibilité aux antibiotiques des souches de staphylococcus aureus communautaires dans la région de Nouakchott (Mauritanie). Mohamed Lemine Ould Salem, Sidi Mohamed Ghaber, Sidi El Wafi Ould Baba, Mohamed Mahmoud Ould Maouloud ...
W.B. van Leeuwen (Willem); D.C. Melles (Damian); A. Alaidan (Alwaleed); M. Al-Ahdal (Mohammed); H.A.M. Boelens (Hélène); S.V. Snijders (Susan); H.F.L. Wertheim (Heiman); E. van Duijkeren (Engeline); J.K. Peeters (Justine); P.J. van der Spek (Peter); R.F.J. Gorkink (Raymond); G. Simons (Guus); H.A. Verbrugh (Henri); A.F. van Belkum (Alex)
textabstractComparative genomics were used to assess genetic differences between Staphylococcus aureus strains derived from infected animals versus colonized or infected humans. A total of 77 veterinary isolates were genetically characterized by high-throughput amplified fragment length polymorphism
Slabbekoorn, M.; Horlings, H. M.; van der Meer, J. T. M.; Windhausen, A.; Van der Sloot, J. A. P.; Lagrand, W. K.
Despite improved diagnostic tools and expanded treatment options, left-sided native valve endocarditis caused by Staphylococcus aureus infection remains a serious and destructive disease. The high morbidity and mortality, however, can be reduced by early recognition, correct diagnosis, and
S. van den Berg (Sanne)
markdownabstract__Abstract__ Staphylococcus aureus is an opportunistic pathogen that causes a variety of infections, ranging from mild skin infections like furuncles and impetigo, to severe, lifethreatening infections including endocarditis, osteomyelitis and pneumonia. Invasive infections are
Sep 5, 2015 ... Materials and Methods: Nasal samples were taken from anterior nares ..... 3599 preoperative nasal cultures for a year and found 16.6% .... methicillin‑resistant and methicillin‑susceptible Staphylococcus aureus in nursing.
Liu, Cindy M.; Price, Lance B.; Hungate, Bruce A.; Abraham, Alison G.; Larsen, Lisbeth A.; Christensen, Kaare; Stegger, Marc; Skov, Robert; Andersen, Paal Skytt
The human microbiome can play a key role in host susceptibility to pathogens, including in the nasal cavity, a site favored by Staphylococcus aureus. However, what determines our resident nasal microbiota—the host or the environment—and can interactions among nasal bacteria determine S. aureus colonization? Our study of 46 monozygotic and 43 dizygotic twin pairs revealed that nasal microbiota is an environmentally derived trait, but the host’s sex and genetics significantly influence nasal bacterial density. Although specific taxa, including lactic acid bacteria, can determine S. aureus colonization, their negative interactions depend on thresholds of absolute abundance. These findings demonstrate that nasal microbiota is not fixed by host genetics and opens the possibility that nasal microbiota may be manipulated to prevent or eliminate S. aureus colonization. PMID:26601194
Tsuchikama, Kyoji; Shimamoto, Yasuhiro; Anami, Yasuaki
The accessory gene regulator (agr) of Staphylococcus aureus coordinates various pathogenic events and is recognized as a promising therapeutic target for virulence control. S. aureus utilizes autoinducing peptides (AIPs), cyclic-peptide signaling molecules, to mediate the agr system. Despite the high potency of synthetic AIP analogues in agr inhibition, the potential of AIP molecules as a delivery vehicle for antibacterial agents remains unexplored. Herein, we report that truncated AIP scaffolds can be fused with fluorophore and cytotoxic photosensitizer molecules without compromising their high agr inhibitory activity, binding affinity to the receptor AgrC, or cell specificity. Strikingly, a photosensitizer-AIP conjugate exhibited 16-fold greater efficacy in a S. aureus cell-killing assay than a nontargeting analogue. These findings highlight the potential of truncated AIP conjugates as useful chemical tools for in-depth biological studies and as effective anti-S. aureus agents.
Haaber, J.; Cohn, M. T.; Petersen, A.
culture. When grown in such liquid cultures, the human pathogen Staphylococcus aureus is characterized by its aggregation of single cells into clusters of variable size. Here, we show that aggregation during growth in the laboratory standard medium tryptic soy broth (TSB) is common among clinical...... and laboratory S. aureus isolates and that aggregation may introduce significant bias when applying standard enumeration methods on S. aureus growing in laboratory batch cultures. We provide a simple and efficient sonication procedure, which can be applied prior to optical density measurements to give...... an accurate estimate of cellular numbers in liquid cultures of S. aureus regardless of the aggregation level of the given strain. We further show that the sonication procedure is applicable for accurate determination of cell numbers using agar plate counting of aggregating strains....
Soong, Grace; Paulino, Franklin; Wachtel, Sarah; Parker, Dane; Wickersham, Matthew; Zhang, Dongni; Brown, Armand; Lauren, Christine; Dowd, Margaret; West, Emily; Horst, Basil; Planet, Paul; Prince, Alice
Skin is the most common site of Staphylococcus aureus infection. While most of these infections are self-limited, recurrent infections are common. Keratinocytes and recruited immune cells participate in skin defense against infection. We postulated that S. aureus is able to adapt to the milieu within human keratinocytes to avoid keratinocyte-mediated clearance. From a collection of S. aureus isolated from chronically infected patients with atopic dermatitis, we noted 22% had an agr mutant-like phenotype. Using several models of human skin infection, we demonstrate that toxin-deficient, agr mutants of methicillin-resistant S. aureus (MRSA) USA300 are able to persist within keratinocytes by stimulating autophagy and evading caspase-1 and inflammasome activation. MRSA infection induced keratinocyte autophagy, as evidenced by galectin-8 and LC3 accumulation. Autophagy promoted the degradation of inflammasome components and facilitated staphylococcal survival. The recovery of more than 58% agr or RNAIII mutants (P Soong et al.
Jan 26, 2011 ... Erythromycin, Chloramphenicol, Cotrimoxazole, Tetracycline, Penicillin, Ciprofloxacin, Ofloxacin, Levofloxacin, Ceftriaxone, Amoxycillin and vancomycin were 92.4% .... Kirmany N, Tuazon CV, Alling D. Carriage of Staphylococcus aureus among patients receiving allergy injections. Ann allergy. 1980;.
Stull, Jason W.; Kenney, Daniel G.; Slavić, Durda; Weese, J Scott
A 6-hour-old alpaca was presented for evaluation of respiratory difficulty. As part of routine surveillance, methicillin-resistant Staphylococcus aureus (MRSA) was identified from a nasal swab taken upon admission to the hospital. No signs of MRSA infection were noted. The MRSA strain recovered was a human epidemic clone that has been associated with horses. Methicillin-resistant S. aureus colonization can occur in camelids, and the potential animal and public health risks require consideration.
Ahmed S Attia
Full Text Available The Staphylococcus aureus HrtAB system is a hemin-regulated ABC transporter composed of an ATPase (HrtA and a permease (HrtB that protect S. aureus against hemin toxicity. S. aureus strains lacking hrtA exhibit liver-specific hyper-virulence and upon hemin exposure over-express and secrete immunomodulatory factors that interfere with neutrophil recruitment to the site of infection. It has been proposed that heme accumulation in strains lacking hrtAB is the signal which triggers S. aureus to elaborate this anti-neutrophil response. However, we report here that S. aureus strains expressing catalytically inactive HrtA do not elaborate the same secreted protein profile. This result indicates that the physical absence of HrtA is responsible for the increased expression of immunomodulatory factors, whereas deficiencies in the ATPase activity of HrtA do not contribute to this process. Furthermore, HrtB expression in strains lacking hrtA decreases membrane integrity consistent with dysregulated permease function. Based on these findings, we propose a model whereby hemin-mediated over-expression of HrtB in the absence of HrtA damages the staphylococcal membrane through pore formation. In turn, S. aureus senses this membrane damage, triggering the increased expression of immunomodulatory factors. In support of this model, wildtype S. aureus treated with anti-staphylococcal channel-forming peptides produce a secreted protein profile that mimics the effect of treating DeltahrtA with hemin. These results suggest that S. aureus senses membrane damage and elaborates a gene expression program that protects the organism from the innate immune response of the host.
Diawara, Idrissa; Bekhti, Khadija; Elhabchi, Driss; Saile, Rachid; Elmdaghri, Naima; Timinouni, Mohammed; Elazhari, Mohamed
Staphylococcus aureus (S. aureus) nasal carriage may be responsible for some serious infections in hemodialyzed patients. The main target of this study was to estimate the prevalence of S. aureus nasal carriage in hemodialysis outpatients and medical staff in hemodialysis centers specifically in Fez region. The second target is to identify the risks of colonization, resistance pattern of isolates and their virulence toxin genes. Nasal swab specimens were obtained from 143 hemodialyzed outpatients and 32 medical staff from January to June 2012. Each participant completed a short questionnaire. Nasal carriage of S. aureus was demographically related (age, gender, hemodialysis duration), comorbidity (diabetes, malignancy) and exposure to health care (dialysis staff, hospitalization). PCR (Polymerase Chain Reaction) were used on all the isolates in the research of twelve staphylococcal enterotoxins genes. Also the PCR was used to investigate on the three factors epidermal cell differentiation inhibitors; three exfoliatin toxins; two leukotoxins; the toxic shock syndrome toxin-1 and the hemolysin beta genes. Nasal screening revealed 38.16%, 50% and 18.75% S. aureus carries in chronic, acute hemodialysis patients and medical staff, respectively. Only young participants were likely to be S. aureus carries (p = 0.002). But there were no gender differences between the isolate carriers and non-carriers or some comorbidity factors such as viral hepatitis B and C, HIV (Human Immunodeficiency Virus) infections, diabetes, chronic smoking, recent hospitalization or antibiotic therapy. Out of all isolates, only one (1.61%) was methicillin-resistant and Twenty-one (33.87%) had at least two virulence toxin genes. Knowledge and monitoring of antibiotic resistance profile and virulence of S. aureus carriage are essential in the treatment of infections generated by this pathogen, as well as in the control of clonal dissemination and prevent the spread of S. aureus resistance.
Khan, Inshad Ali; Mirza, Zahid Mehmood; Kumar, Ashwani; Verma, Vijeshwar; Qazi, Ghulam Nabi
Piperine, a trans-trans isomer of 1-piperoyl-piperidine, in combination with ciprofloxacin markedly reduced the MICs and mutation prevention concentration of ciprofloxacin for Staphylococcus aureus, including methicillin-resistant S. aureus. The enhanced accumulation and decreased efflux of ethidium bromide in the wild-type and mutant (CIPr-1) strains in the presence of piperine suggest its involvement in the inhibition of bacterial efflux pumps. PMID:16436753
Branch, US Army Dental and Trauma Research Detachment, Institute of Surgical Research, Fort Sam Houston, TX 78234, United States a b s t r a c ta r t...hlgC), are up regulated Journal of Microbiological Methods 90 (2012) 115–118 ⁎ Corresponding author at: 3650 Chambers Pass, Bldg 3610, US Army Dental ...aureus biofilm formation in real time, we used overnight green fluores cent protein (GFP) tagged clinical isolate S. aureus UAMS 1 (University of
Subhankari Prasad Chakraborty; Santanu Kar Mahapatra; Somenath Roy
Objective: To observe the biochemical characters and antibiotic susceptibility of isolated Staphylococcus aureus (S. auerus) strains against some conventional and traditional antibiotics. Methods: Thirty post operative pathogenic isolated S. aureus strains were used in this study. Bacterial culture was done in Mueller-Hinton broth at 37 °C. Characters of these strains were determined by traditional biochemical tests such as hydrolysis test of gelatin, urea, galactose, starch and protein, a...
Full Text Available BACKGROUND: Antibiotic-resistant Staphylococcus aureus infections have increased dramatically in the community, yet S. aureus nasal colonization has remained stable. The objectives of this study were to determine if S. aureus colonization is a useful proxy measure to study disease transmission and infection in community settings, and to identify potential community reservoirs. METHODOLOGY/PRINCIPAL FINDINGS: Randomly selected households in Northern Manhattan, completed a structured social network questionnaire and provided nasal swabs that were typed by pulsed field gel electrophoresis to identify S. aureus colonizing strains. The main outcome measures were: 1 colonization with S. aureus; and 2 recent serious skin infection. Risk factor analyses were conducted at both the individual and the household levels; logistic regression models identified independent risks for household colonization and infection. RESULTS: 321 surveyed households contained 914 members. The S. aureus prevalence was 25% and MRSA was 0.4%. More than 40% of households were colonized. Recent antibiotic use was the only significant correlate for household colonization (p = .002. Seventy-eight (24% households reported serious skin infection. In contrast with colonization, five of the six risk factors that increased the risk of skin infection in the household at the univariate level remained independently significant in multivariable analysis: international travel, sports participation, surgery, antibiotic use and towel sharing. S. aureus colonization was not significantly associated with serious skin infection in any analysis. Among multiperson households with more than one person colonized, 50% carried the same strain. CONCLUSIONS/SIGNIFICANCE: The lack of association between S. aureus nasal colonization and serious skin infection underscores the need to explore alternative venues or body sites that may be crucial to transmission. Moreover, the magnitude of colonization and
Prax, Marcel; Mechler, Lukas; Weidenmaier, Christopher; Bertram, Ralph
Treatment of Staphylococcus aureus in stationary growth phase with high doses of the antibiotic daptomycin (DAP) eradicates the vast majority of the culture and leaves persister cells behind. Despite resting in a drug-tolerant and dormant state, persister cells exhibit metabolic activity which might be exploited for their elimination. We here report that the addition of glucose to S. aureus persisters treated with DAP increased killing by up to five-fold within one hour. This glucose-DAP effe...
Stauff, Devin L; Pishchany, Gleb; Whitwell, Corbin W; Torres, Victor J; Skaar, Eric P; Friedman, David J.
Staphylococcus aureus pathogenesis is significantly influenced by the iron status of the host. However, the regulatory impact of host iron sources on S. aureus gene expression remains unknown. In this study, we combine multivariable difference gel electrophoresis and mass spectrometry with multivariate statistical analyses to systematically cluster cellular protein response across distinct iron-exposure conditions. Quadruplicate samples were simultaneously analyzed for alterations in protein ...
Verhoeven, P O; Gautret, P; Haddar, C H; Benkouiten, S; Gagnaire, J; Belhouchat, K; Grattard, F; Charrel, R; Pozzetto, B; Drali, T; Lucht, F; Brouqui, P; Memish, Z A; Berthelot, P; Botelho-Nevers, E
During the 2012 Hajj season, the risk of acquisition of Staphylococcus aureus nasal carriage in a cohort of French pilgrims was 22.8%, and was statistically associated with the acquisition of viral respiratory pathogens (p 0.03). The carriage of S. aureus belonging to the emerging clonal complex 398 significantly increased following the pilgrimage (p < 0.05). Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
Bogdali, Anna M; Anna, Bogdali M; Grazyna, Antoszczyk; Wojciech, Dyga; Aleksander, Obtulowicz; Anna, Bialecka; Andrzej, Kasprowicz; Zofia, Magnowska; Krystyna, Obtulowicz
The increase of nickel air pollution is supposed to frequent side effects of nickel action related to virulence potential of Staphylococcus aureus in patients with nickel allergy in atopic dermatitis. The goal was to investigate the relationship between nickel allergy and infection by S. aureus in atopic dermatitis. Nickel allergy was confirmed in atopic patients and excluded in healthy volunteers using patch testing. Infection by S. aureus was tested in atopic patients and healthy volunteers by use of API Staph system. The specific IgE for staphylococcal enterotoxin A and B were measured. Secretion of IFN-g, IL-2, IL-13 by PBMC under nickel sulfate and the enterotoxins A and B stimulations were studied with ELISpot. We found the increased number of infections by S. aureus in atopic patients with nickel allergy in comparison to atopic patients and healthy volunteers without nickel allergy. The elevated secretion of IL-2 under nickel sulfate stimulation in vitro was exclusively found in atopic patients with nickel allergy infected by S. aureus. Our data suggest that nickel allergy and infection by S. aureus are linked in atopic dermatitis. Copyright © 2015 Elsevier GmbH. All rights reserved.
Bischoff, Werner E; Wallis, Michelle L; Tucker, Brian K; Reboussin, Beth A; Pfaller, Michael A; Hayden, Frederick G; Sherertz, Robert J
Staphylococcus aureus is among the most important pathogens in today's hospital setting. The effects of sneezing on the airborne dispersal of S. aureus and other bacteria were assessed in 11 healthy nasal S. aureus carriers with experimentally induced rhinovirus colds. Airborne dispersal was studied by volumetric air sampling in 2 chamber sessions with and without histamine-induced sneezing. After 2 days of preexposure measurements, volunteers were inoculated with a rhinovirus and monitored for 14 days. Daily quantitative nasal- and skin-culture samples for bacteria and nasal-culture samples for rhinovirus were obtained, cold symptoms were assessed, and volunteer activities were recorded during sessions. All participants developed a cold. Sneezing caused a 4.7-fold increase in the airborne dispersal of S. aureus, a 1.4-fold increase in coagulase-negative staphylococci (CoNS), and a 3.9-fold increase in other bacteria (P Rhinovirus exposure did not change the frequency of sneezing or airborne dispersal. Having respiratory allergies increased the spread of S. aureus by 3.8-fold during sneezing sessions (P effect of dispersing S. aureus.
Full Text Available Introduction: Colonization of the nasal mucosa by Staphylococcus aureus set a carrier state. Which is recognized as a potential source of infection and a high risk factor for subsequent invasive infections. The prevalence of nasal carriage of this germ in disabled children in Paraguay is not known, thus contributing to the knowledge of their frequency and evaluate the profile of sensitivity to common antimicrobials was conducted this study, from May to July 2015. Objective: to determine the prevalence of Staphylococcus aureus nasal carriage and profile of antimicrobial resistance in disabled children. Materials and Methods: A descriptive cross-sectional study in which 80 nasal swabs of children, who attended the service laboratory of SENADIS (Secretaria Nacional por los Derechos Humanos de las Personas con Discapacidad. The identification and sensitivity of germ was accomplished by conventional testing. Results: 80 pediatric patients, 46 boys and 34 girls. 18 isolates of Staphylococcus aureus were obtained, corresponding to a prevalence of 22,5%. Susceptibility testing indicated that 14 strains were MSSA (Methicillin – Sensitive Staphylococcus aureus and 4 RMSA ( Methicillin- resistant Staphylococcus aureus. Conclusion: The prevalence of Staphylococcus aureus in a population with its own characteristics provides valuable data for the epidemiology, reflecting the need for continued vigilance and take steps to reduce associated infections. The detection of RMAR evidences their progress; it is important to evaluate the empirical treatment to primary care.
Costa, Sofia S.; Junqueira, Elisabete; Palma, Cláudia; Viveiros, Miguel; Melo-Cristino, José; Amaral, Leonard; Couto, Isabel
Resistance mediated by efflux has been recognized in Staphylococcus aureus in the last few decades, although its clinical relevance has only been recognized recently. The existence of only a few studies on the individual and overall contribution of efflux to resistance phenotypes associated with the need of well-established methods to assess efflux activity in clinical isolates contributes greatly to the lack of solid knowledge of this mechanism in S. aureus. This study aims to provide information on approaches useful to the assessment and characterization of efflux activity, as well as contributing to our understanding of the role of efflux to phenotypes of antibiotic resistance and biocide tolerance in S. aureus clinical isolates. The results described show that efflux is an important contributor to fluoroquinolone resistance in S. aureus and suggest it as a major mechanism in the early stages of resistance development. We also show that efflux plays an important role on the reduced susceptibility to biocides in S. aureus, strengthening the importance of this long neglected resistance mechanism to the persistence and proliferation of antibiotic/biocide-resistant S. aureus in the hospital environment. PMID:27029294
Ansari, Shamshul; Nepal, Hari Prasad; Gautam, Rajendra; Rayamajhi, Nabin; Shrestha, Sony; Upadhyay, Goma; Acharya, Anju; Chapagain, Moti Lal
Staphylococcus aureus is the most commonly isolated organism from the different clinical samples in hospital. The emergence and dissemination of methicillin resistant Staphylococcus aureus (MRSA) and growing resistance to non-beta-lactam antibiotics is making treatment of infections due to this organism increasingly difficult. This study was conducted to determine the frequency of Staphylococcus aureus isolated from different clinical samples, rates of MRSA and full antibiotic susceptibility profiles. Clinical samples were cultured and Staphylococcus aureus was identified using standard microbiological methods recommended by the American Society for Microbiology (ASM). Methicillin resistance was confirmed using cefoxitin and oxacillin disks. Inducible clindamycin resistance was identified using D-zone test. From the processed samples, 306 isolates of Staphylococcus aureus were recovered. All the isolates were susceptible to vancomycin and teicoplanin. Methicillin resistance was observed in 43.1% of isolates while inducible clindamycin resistance in 12.4% of the isolates. The results of our study reveals that rates of resistance to commonly prescribed antibiotics in Staphylococcus aureus clinical isolates is high. In particular, rate of methicillin resistance is alarming, prompting concern on the rational use of antibiotics and vigilant laboratory-based surveillance of resistance rates in Nepal.
Etinosa O. Igbinosa
Full Text Available The emergence of antibiotic-resistant bacteria in food animals is a potential public health concern. Staphylococci are a significant opportunistic pathogen both in humans and dairy cattle. In the present study, the genotypic characterization of methicillin-resistant staphylococcal strains recovered from dairy cattle in a rural community (Okada, Edo State, Nigeria was investigated. A total of 283 samples from cattle (137 milk samples and 146 nasal swabs were assessed between February and April 2015. Antimicrobial susceptibility was performed by Kirby-Bauer disc diffusion method. Polymerase chain reaction (PCR assay was employed for the detection of 16S rRNA, mecA and Panton-Valentine Leucocidinis (PVL genes. The staphylococcal strains were identified through partial 16S ribosomal ribonucleic acids (rRNA nucleotide sequencing, and Basic Local Alignment Search Tool (BLAST analysis of the gene sequence showed that the staphylococcal strains have 96%–100% similarity to Staphylococcus aureus (30, S. epidermidis (17, S. haemolyticus (15, S. saprophyticus (13, S. chromogenes (8, S. simulans (7, S. pseudintermedius (6 and S. xylosus (4. Resistance of 100% was observed in all Staphylococcus spp. against MET, PEN, CLN, CHL and SXT. Multi-drug resistant (MDR bacteria from nasal cavities and raw milk reveals 13 isolates were MDR against METR, PENR, AMXR, CLNR, CHLR, SXTR CLXR, KANR, ERYR, and VANR. Of all isolates, 100% harboured the mecA gene, while 30% of the isolates possess the PVL gene. All S. aureus harboured the PVL gene while other Staphylococcus spp. were negative for the PVL gene. The presence of methicillin-resistant Staphylococcus spp. isolates in dairy cattle is a potential public health risk and thus findings in this study can be used as a baseline for further surveillance.
Rong, Dongli; Wu, Qingping; Xu, Mingfang; Zhang, Jumei; Yu, Shubo
Staphylococcus aureus is an important food-borne opportunistic pathogen that frequently causes severe blood and tissue infections or even fatal illnesses. Although S. aureus has been extensively studied in livestock and poultry foods in China, limited information has been reported in aquatic products. Accordingly, in this study, we aimed to characterize S. aureus in aquatic products purchased from retail markets in China. In total, 320 aquatic food samples were collected from 32 provincial capitals in China. The results showed that 119 samples (37.2%, 119/320) were positive for S. aureus by both qualitative and quantitative analyses. The contamination levels of 78.2% of samples ranged from 0.3 to 10 MPN/g, and six samples exceeded 110 MPN/g. A total of 119 S. aureus isolates from positive samples were selected to evaluate virulence factors, antibiotic resistance, and molecular characteristics. All S. aureus isolates were evaluated for the presence of 11 virulence genes by multiplex polymerase chain reaction, and α-hemolysin ( hlα , 84.9%), fibronectin-binding protein A ( fnbA , 79.0%), S. aureus enterotoxin E ( see , 53.8%), and Panton-Valentine leucocidin ( pvl , 50.4%) were identified as the major genes. These genes formed 56 different profiles, with the major profile identified as pvl - hlα - fnbA (28.6%). The antimicrobial susceptibility of all isolates was analyzed through the disk diffusion method, and the results showed high resistance to β-lactams, macrolides and tetracyclines, but susceptibility to linezolid and vancomycin. In addition, 26 sequence types (STs) were obtained via multilocus sequence typing, including seven novel STs, among which ST1 (20.2%), ST15 (18.5%), and ST188 (13.4%) were the most common STs. All the isolates were mecC negative, but nine isolates carrying mecA were evaluated by staphylococcal cassette chromosome mec (SCC mec ) typing, all of which were SCC mec III or SCC mec IV types. Isolates of SCCmec III showed a high prevalence
Zouhir, Abdelmajid; Taieb, Malek; Lamine, Mohamed Ashraf; Cherif, Ammar; Jridi, Taoufik; Mahjoubi, Basma; Mbarek, Sarra; Fliss, Ismail; Nefzi, Adel; Sebei, Khaled; Ben Hamida, Jeannette
Staphylococcus aureus and methicillin-resistant S. aureus are major pathogens. The antimicrobial peptides and essential oils (EOs) display narrow- or broad-spectrum activity against bacteria including these strains. A centralized resource, such as a database, designed specifically for anti-S. aureus/anti-methicillin-resistant S. aureus antimicrobial peptides and EOs is therefore needed to facilitate the comprehensive investigation of their structure/activity associations and combinations. The database ANTISTAPHYBASE is created to facilitate access to important information on antimicrobial peptides and essential peptides against methicillin-resistant S. aureus and S. aureus. At the moment, the database contains 596 sequences of antimicrobial peptides produced by diverse organisms and 287 essential oil records. It permits a quick and easy search of peptides based on their activity as well as their general, physicochemical properties and literature data. These data are very useful to perform further bioinformatic or chemometric analysis and would certainly be useful for the development of new drugs for medical use. The ANTISTAPHYBASE database is freely available at: https://www.antistaphybase.com/ .
Jensen, Slade O.; Vaska, Vikram L.; Espedido, Björn A.; Paterson, David L.; Gosbell, Iain B.
Summary: Staphylococcus aureus bacteremia (SAB) is an important infection with an incidence rate ranging from 20 to 50 cases/100,000 population per year. Between 10% and 30% of these patients will die from SAB. Comparatively, this accounts for a greater number of deaths than for AIDS, tuberculosis, and viral hepatitis combined. Multiple factors influence outcomes for SAB patients. The most consistent predictor of mortality is age, with older patients being twice as likely to die. Except for the presence of comorbidities, the impacts of other host factors, including gender, ethnicity, socioeconomic status, and immune status, are unclear. Pathogen-host interactions, especially the presence of shock and the source of SAB, are strong predictors of outcomes. Although antibiotic resistance may be associated with increased mortality, questions remain as to whether this reflects pathogen-specific factors or poorer responses to antibiotic therapy, namely, vancomycin. Optimal management relies on starting appropriate antibiotics in a timely fashion, resulting in improved outcomes for certain patient subgroups. The roles of surgery and infectious disease consultations require further study. Although the rate of mortality from SAB is declining, it remains high. Future international collaborative studies are required to tease out the relative contributions of various factors to mortality, which would enable the optimization of SAB management and patient outcomes. PMID:22491776
Iskandar, Aline; Nguyen, Ngan; Kolmos, Hans Jørn
Staphylococcus aureus (Sa) is an important cause of hospital-acquired infections, and nasal carriage of Sa is common among health care workers. This study was designed to measure the airborne dispersal of Sa and other bacteria from such carriers and to investigate whether the use of cap, gown, gloves, and mask could reduce this dispersal. A total of 13 nasal Sa carriers were identified among 63 persons screened for Sa nasal carriage. The volunteers were studied for airborne dispersal of Sa in four different situations: quiet breathing, movements of the arms, whispering and loud talking. These activities were performed with and without gown, gloves, mask and cap upon street clothes. The study showed that the highest number of Sa and bacteria in total was dispersed into the air when the volunteers were moving and wearing only their street clothes. The dispersal of Sa into the air was reduced into a minimum by wearing cap, gown and gloves, and no further significant decrease was achieved by wearing a mask. This applied for all volunteers except for one, who had to wear a mask in order to reduce his dispersal of Sa to a minimum. The total dispersal of bacteria was significantly reduced by wearing cap, gown and gloves; however, to reduce this dispersal to a minimum, volunteers also had to wear a mask. Our study supports the rational basis that gown, cap, gloves and mask should be used not only in the operating theatre, but also while e.g. inserting central venous catheters.
Full Text Available Background: Staphylococcus aureus (S. aureus is one of the major pathogens causing chronic infections. The ability of S. aureus to acquire resistance to a diverse range of antimicrobial compounds results in limited treatment options, particularly in methicillin-resistant S. aureus (MRSA. A mechanism by which S. aureus develops reduced susceptibility to antimicrobials is through the formation of small colony variants (SCVs. Infections by SCVs of S. aureus are an upcoming problem due to difficulties in laboratory diagnosis and resistance to antimicrobial therapy. Methods: A prospective study was performed on 120 patients diagnosed with both type 2 diabetes mellitus and infected diabetic foot ulcers. The study was carried out from July 2012 to December 2013 in Hospital General de Mexico. The samples were cultured in blood agar, mannitol salt agar, and MacConkey agar media, and incubated at 37°C in aerobic conditions. Results: We describe the first known cases of diabetic foot infections caused by MRSA-SCVs in patients diagnosed with type 2 diabetes mellitus and infected diabetic foot ulcers. In all of our cases, the patients had not received any form of gentamicin therapy. Conclusions: The antibiotic therapy commonly used in diabetic patients with infected diabetic foot ulcers fails in the case of MRSA-SCVs because the intracellular location protects S. aureus-SCVs from the host's defenses and also helps them resist antibiotics. The cases studied in this article add to the spectrum of persistent and relapsing infections attributed to MRSA-SCVs and emphasizes that these variants may also play a relevant role in diabetic foot infections.
Cervantes-García, Estrella; García-Gonzalez, Rafael; Reyes-Torres, Angélica; Resendiz-Albor, Aldo Arturo; Salazar-Schettino, Paz María
Background : Staphylococcus aureus (S. aureus) is one of the major pathogens causing chronic infections. The ability of S. aureus to acquire resistance to a diverse range of antimicrobial compounds results in limited treatment options, particularly in methicillin-resistant S. aureus (MRSA). A mechanism by which S. aureus develops reduced susceptibility to antimicrobials is through the formation of small colony variants (SCVs). Infections by SCVs of S. aureus are an upcoming problem due to difficulties in laboratory diagnosis and resistance to antimicrobial therapy. Methods : A prospective study was performed on 120 patients diagnosed with both type 2 diabetes mellitus and infected diabetic foot ulcers. The study was carried out from July 2012 to December 2013 in Hospital General de Mexico. The samples were cultured in blood agar, mannitol salt agar, and MacConkey agar media, and incubated at 37°C in aerobic conditions. Results : We describe the first known cases of diabetic foot infections caused by MRSA-SCVs in patients diagnosed with type 2 diabetes mellitus and infected diabetic foot ulcers. In all of our cases, the patients had not received any form of gentamicin therapy. Conclusions : The antibiotic therapy commonly used in diabetic patients with infected diabetic foot ulcers fails in the case of MRSA-SCVs because the intracellular location protects S. aureus-SCVs from the host's defenses and also helps them resist antibiotics. The cases studied in this article add to the spectrum of persistent and relapsing infections attributed to MRSA-SCVs and emphasizes that these variants may also play a relevant role in diabetic foot infections.
Full Text Available The objective of our investigation was to determine how certain factors (the environment, treatment, prevention, animal affect udder infection with Staphylococcus aureurs (S. aureus bacteria. A questionnaire investigated the effect of different factors on the frequency of infection with S. aureus bacteria. We established that prevention, treatment on the basis of results of bacteriological examinations and antibiograms, and the elimination of the negative influence of the environment, form a basis for reducing the frequency of udder infections. We verified the questionannire results with the variant analysis method and established that the effect of the environment significantly digresses from the other factors (prevention treatment and diagnosis, animal. Our results show that the breeder, with good prevention and good treatment of mastitis, often disregards the effects of the barn and the environment in which the cows are maintained. Poor barn conditions have a negative effect on cow resistance and at the same time enable the existence and multiplication of pathogenic species of bacteria. In addition to the maintenance conditions, one must not forget prevention and therapy of mammary gland inflammation, either. On the grounds of our previous investigations (Pengov et al., 2000, we recommend for the therapy of mammary gland inflammation the use of a combination of amoxicillin and clavulonic acid, and as prevention of mammary gland inflammation the use of an udder ointment.
Pulcini, Céline; Matta, Matta; Mondain, Véronique; Gaudart, Alice; Girard-Pipau, Fernand; Mainardi, Jean-Luc; Dellamonica, Pierre
To identify factors associated with complicated Staphylococcus aureus bacteremia (SAB) in adults. Prospective observational multicenter study during 2 years in Nice University Hospital and during 6 months in the Hôpital Européen Georges Pompidou, Paris, including all adult inpatients with SAB assessed by an Infectious Diseases (ID) specialist. We included 104 SAB (79 in Nice and 25 in Paris), of which 45 were complicated, including 18 endocarditis and 23 bone and joint infections. A concomitant urine sample was performed in 65% of the cases, showing S. aureus bacteriuria 23/68 (34%) times. Blood cultures were drawn 48-96h after an appropriate antibiotic therapy had been started in 70 of the 104 cases (67%) and were positive in 28 cases (40%). The 3 following factors were found to be associated with complicated SAB in univariate analysis: community acquisition (56% vs 26%, P=0.002), concomitant bacteriuria (47% vs 19%, P=0.016) and persistent bacteremia (55% vs 26%, P=0.016). This last factor was associated with endocarditis, but not with other complications such as bone and joint infections.
Langone, J.J.; Das, C.; Bennett, D.; Terman, D.S. (Baylor Univ., Houston, TX (USA). Coll. of Medicine)
Radioimmunoassays have been developed that can detect nanogram amounts of protein A (SpA), a product generated by Staphylococcus aureus that binds selectively to the Fc region of IgG from most mammalian species. Competition assays for fluid phase SpA utilize antibodies produced in chickens, /sup 125/I-labeled SpA as the tracer molecule, and either F(ab')/sub 2/ fragments of rabbit IgG anti-chicken IgG or 40% ammonium sulfate as the precipitating agent to separate antigen-antibody complexes from free antigen. The double antibody assay could be carried out in serum from species that form only soluble complexes with SpA (e.g., rabbit), that react poorly with SpA (e.g., rat) or under appropriate conditions in serum from species (e.g., dog) that show high reactivity with SpA and form precipitating complexes. Chicken antibodies prepared by affinity chromatography on SpA-Sepharose and labeled with /sup 125/I were used in a direct binding assay for SpA present either on the cell wall of Cowan strain I or Wood 46 bacteria, in insoluble complexes prepared from SpA and whole serum or purified IgG, or in C1q binding complexes that were formed by passage of serum from normal or tumor bearing humans or dogs over SpA-collodion charcoal. Since both types of assays could detect SpA even in the presence of serum or IgG, they offer advantages over other techniques in which the SpA-Fc interaction may interfere.
Gongora, Carmen Espinosa; Chrobak, Dorota; Moodley, Arshnee
The current knowledge of the occurrence and diversity of Staphylococcus aureus in animals is largely biased in favour MRSA and domestic animals. In order to generate novel information on the ecology and population structure of this bacterial species in the animal kingdom, we investigated the occu...... MSSA belonging to fourteen spa types, including three novel spa types. MLST revealed the occurrence of seven STs. The study of the ecology of commensal S. aureus in captive wild animals revealed that ST133 has a broader host range than previously thought.......The current knowledge of the occurrence and diversity of Staphylococcus aureus in animals is largely biased in favour MRSA and domestic animals. In order to generate novel information on the ecology and population structure of this bacterial species in the animal kingdom, we investigated...... the occurrence and genotypic diversity of S. aureus in a range of animal species kept at the Copenhagen Zoo. We sampled 146 animals belonging to 25 mammalian species and 21 reptiles belonging to six species. A total of 59 S. aureus isolates were found in 10 of the 25 mammalian species tested. All isolates were...
Ashimav Deb Sharma
Full Text Available Aim: To evaluate the role of nasal carriage of Staphylococcus aureus in patients suffering from chronic urticaria. Method: All total 82 patients were included for this study. Study group comprised 57 patients with chronic urticaria and the control group comprised 25 healthy volunteers. Nasal swab specimens were taken from all the 82 patients for bacterial culture and antimicrobial sensitivity. Patients with chronic urticaria who had positive growth for S. aureus were treated with sensitive antimicrobial agent. Nasal swab specimens were taken again from all the patients who received antimicrobial therapy to ensure complete eradication of S. aureus. All patients were followed up for a period of 6 weeks after the treatment. Urticarial activity was measured with the help of urticarial activity score. Results: S. aureus was detected in swab specimens from the nasal cavity in 32 patients in the study group and 7 patients in the control group. In the study group, after the antimicrobial treatment, 9 patients (28.12% had complete recovery from urticaria during the follow-up period; 4 patients (12.5% showed partial recovery from urticaria while the remaining patients (59.37% continued to suffer from urticaria. Conclusion: This study showed that nasal carriage of S. aureus can act as an etiological factor in chronic urticaria.
Full Text Available Epidemiological research in developed and developing countries, had found meat products as the principal cause for foodbourne diseases. In addition, Salmonella and Staphyococcus aureus are well known pathogens for their mayor impact in public health. The objective for the present study consisted on determinate the sanitary quality from chorizo and longaniza samples from several butcheries in Guadalajara, Jalisco, Mexico. Samples of chorizo (50 and longaniza (50 were obtained from different points in Guadalajara metropolis. Presence of Salmonella and recounts for S. aureus were tested in 25 g samples. Procedure was followed according Mexican NOM 145-SSA1-1995 methods. In chorizo, 18 samples were positive to Salmonella. The count of S. aureus showed a mean of 24,600 UFC/g. On the other hand, 24 samples of longaniza were positive to Salmonella spp. In this case, the mean of S. aureus was 7,800 UFC/g. The serotypes of Salmonella spp were: Derby (30%, Adelaile (17%, Azteca (15%, Infantis (15%, Muenster(10% y Anatum (13 %. The high positivity of Salmonella spp. and S. aureus is a potential hazard to consumers.
SUMMARY The ability to produce water-soluble proteins with the capacity to oligomerize and form pores within cellular lipid bilayers is a trait conserved among nearly all forms of life, including humans, single-celled eukaryotes, and numerous bacterial species. In bacteria, some of the most notable pore-forming molecules are protein toxins that interact with mammalian cell membranes to promote lysis, deliver effectors, and modulate cellular homeostasis. Of the bacterial species capable of producing pore-forming toxic molecules, the Gram-positive pathogen Staphylococcus aureus is one of the most notorious. S. aureus can produce seven different pore-forming protein toxins, all of which are believed to play a unique role in promoting the ability of the organism to cause disease in humans and other mammals. The most diverse of these pore-forming toxins, in terms of both functional activity and global representation within S. aureus clinical isolates, are the bicomponent leucocidins. From the first description of their activity on host immune cells over 100 years ago to the detailed investigations of their biochemical function today, the leucocidins remain at the forefront of S. aureus pathogenesis research initiatives. Study of their mode of action is of immediate interest in the realm of therapeutic agent design as well as for studies of bacterial pathogenesis. This review provides an updated perspective on our understanding of the S. aureus leucocidins and their function, specificity, and potential as therapeutic targets. PMID:24847020
Reizner, W.; Hunter, J.G.; O’Malley, N.T.; Southgate, R.D.; Schwarz, E.M.; Kates, S.L.
Staphylococcus aureus (S. aureus) osteomyelitis is a significant complication for orthopaedic patients undergoing surgery, particularly with fracture fixation and arthroplasty. Given the difficulty in studying S. aureus infections in human subjects, animal models serve an integral role in exploring the pathogenesis of osteomyelitis, and aid in determining the efficacy of prophylactic and therapeutic treatments. Animal models should mimic the clinical scenarios seen in patients as closely as possible to permit the experimental results to be translated to the corresponding clinical care. To help understand existing animal models of S. aureus, we conducted a systematic search of PubMed & Ovid MEDLINE to identify in vivo animal experiments that have investigated the management of S. aureus osteomyelitis in the context of fractures and metallic implants. In this review, experimental studies are categorized by animal species and are further classified by the setting of the infection. Study methods are summarized and the relevant advantages and disadvantages of each species and model are discussed. While no ideal animal model exists, the understanding of a model’s strengths and limitations should assist clinicians and researchers to appropriately select an animal model to translate the conclusions to the clinical setting. PMID:24668594
Full Text Available Background: Methicillin resistant Staphylococcus aureus (MRSA is one of the most important pathogen in hospitals. Healthcare personnel are the main source of nosocomial infections and identification and control of MRSA carriers can reduce incidence of infections. The aim of this study was to determine the prevalence of MRSA and their antibiotic susceptibility profile among healthcare workers in Gorgan.Materials and Method: 333 healthcare workers were participated in this cross-sectional study in 2009. Samples were taken with sterile cotton swabs from both anterior nares and hands. Swabs were plated immediately on to the mannitol salt agar. Suspected colonies were confirmed as S. aureus by Gram staining, catalase, coagulase and DNase tests. Minimum inhibition concentration by micro dilution broth method was used to determine methicillin resistant strains. Antimicrobial susceptibility to other antibiotics was performed according to NCCLS guidelines by disc diffusion method.Result: Frequency of S.aureus and MRSA carriers among healthcare workers was 24% and 3% respectively. The highest rate of S. aureus and MRSA carriers were observed in operating room staff. Resistance to penicillin was seen in 97.5% of isolates and all strains were sensitive to vancomycin.Conclusions: Frequency of S. aureus and MRSA in healthcare workers was median and rather low respectively. Continual monitoring and control of carriers can reduce distribution of this organism and their infections
Mohammad Mehdi Soltan Dallal
Full Text Available Background During fishing and transport, preservation and quality of fish products are importantas well as storage to prevent the growth of pathogenic and toxin producing bacteria.Staphylococcus aureus is one of the most common causes of sea food-borne diseases worldwidedue to contamination of food by preformed enterotoxins. The aim of this study was to compare theprevalence and contamination of S. aureus in marine and farmed shrimps in Tehran fishery center.Methods: A total of 300 samples, including 150 marine, 150 farmed shrimps were selected duringSeptember 2013 to December 2014. Isolation and identification of S. aureus from isolated sampleswere carried out according to conventional methods, and antibiotic susceptibility test wasperformed by modified Kirby-Bauer disc diffusion method.Results: The results of this study showed that 30% of marine and 20% off armed shrimps werecontaminated with S. aureus. The highest resistance was observed with penicillin and ampicillin,whereas 100% were sensitive to vancomycin, clindamycin, ciprofloxacin, and rifampin.Conclusions: Due to relatively high contamination of shrimp by S. aureus more attention shouldbe given during processing and manufacturing.
Katkowska, Marta; Garbacz, Katarzyna; Stromkowski, Józef
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 Staphylococcus 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. © 2016 APMIS. Published by John Wiley & Sons Ltd.
Full Text Available Curcumin, the major constituent of Curcuma longa L. (Zingiberaceae family or turmeric, commonly used for cooking in Asian cuisine, is known to possess a broad range of pharmacological properties at relatively nontoxic doses. Curcumin is found to be effective against Staphylococcus aureus (S. aureus. As demonstrated by in vitro experiment, curcumin exerts even more potent effects when used in combination with various other antibacterial agents. Hence, curcumin which is a natural product derived from plant is believed to have profound medicinal benefits and could be potentially developed into a naturally derived antibiotic in the future. However, there are several noteworthy challenges in the development of curcumin as a medicine. S. aureus infections, particularly those caused by the multidrug-resistant strains, have emerged as a global health issue and urgent action is needed. This review focuses on the antibacterial activities of curcumin against both methicillin-sensitive S. aureus (MSSA and methicillin-resistant S. aureus (MRSA. We also attempt to highlight the potential challenges in the effort of developing curcumin into a therapeutic antibacterial agent.
Mohammad Mehdi Soltan Dallal
Full Text Available Background During fishing and transport, preservation and quality of fish products are importantas well as storage to prevent the growth of pathogenic and toxin producing bacteria.Staphylococcus aureus is one of the most common causes of sea food-borne diseases worldwidedue to contamination of food by preformed enterotoxins. The aim of this study was to compare theprevalence and contamination of S. aureus in marine and farmed shrimps in Tehran fishery center.Methods: A total of 300 samples, including 150 marine, 150 farmed shrimps were selected duringSeptember 2013 to December 2013. Isolation and identification of S. aureus from isolated sampleswere carried out according to conventional methods, and antibiotic susceptibility test wasperformed by modified Kirby-Bauer disc diffusion methodResults: The results of this study showed that 30% of marine and 20% off armed shrimps werecontaminated with S. aureus. The highest resistance was observed with penicillin and ampicillin,whereas 100% were sensitive to vancomycin, clindamycin, ciprofloxacin, and rifampin.Conclusions: Due to relatively high contamination of shrimp by S. aureus more attention shouldbe given during processing and manufacturing.
Staphylococcus aureus is a frequent and major contagious mastitis bacterial pathogen. The antibiotic treatment cure rates vary considerably from 4% to 92%. Staphylococcus aureus readily becomes resistant to antibiotics, resulting in persistent noncurable intramammary infection that usually results i...
M.C. Vos (Margreet); A. Ott (Alewijn); A. Voss (Andreas); J.A.J.W. Kluytmans (Jan); C.M.J.E. Vandenbroucke-Grauls (Christina); M.H.M. Meester (Marlene); P.H.J. van Keulen (Peter); H.A. Verbrugh (Henri); H.F.L. Wertheim (Heiman)
textabstractBACKGROUND: Staphylococcus aureus nasal carriage is a major risk factor for nosocomial S. aureus infection. Studies show that intranasal mupirocin can prevent nosocomial surgical site infections. No data are available on the efficacy of mupirocin in nonsurgical
Zadoks, Ruth Nicolet
Mastitis is the most common and costly production disease affecting dairy cows. Staphylococcus aureus and Streptococcus uberis are two major mastitis-causing pathogens. Staphylococcus aureus is traditionally classified as contagious pathogen, while Streptococcus uberis is classified as environmental
Tenhagen, Bernd-Alois; Scheibe, Nicole; Zucker, Bert-Andree; Köster, Gudrun; Heuwieser, Wolfgang
The proportion of different strains of Staphylococcus aureus was tested in four groups of lactating dairy cows in six herds with a high overall prevalence of Staph. aureus using random amplified polymorphic DNA PCR. Group 1 included primiparous cows in early lactation (250 days in milk). Groups 3 and 4 were multiparous cows in the respective stages of lactation. Eight cows from each group on each farm were tested. Overall quarter prevalence of Staph. aureus ranged from 23.4 to 32.0% in the herds. Of the 130 isolates included in the analysis 86.9% were high prevalence strains (more than three isolates per herd), while 13.1% were strains that were only identified in one or two samples. Low prevalence strains were found in all six herds. The proportion of low prevalence strains was higher in multiparous than in primiparous cows (odds ratio, OR 4.4, 1.2-16.6). It is concluded that low prevalence Staph. aureus strains are common even in herds with a high prevalence of Staph. aureus and that their frequency is lower in primiparous cows than in older cows.
Full Text Available Daptomycin is a lipopeptide antibiotic with a unique mechanism of action on Gram-positive bacteria. It is approved for treatment of skin and soft-tissue infections with Gram-positive bacteria, bacteraemia and right-sided infective endocarditis caused by Staphylococcus aureus. Diminishing susceptibility of S. aureus to daptomycin during treatment of complicated infections and clinical failure have been described. Combinations of daptomycin with other antibiotics including gentamicin, rifampin, beta-lactams, trimethoprim/sulfamethoxazole (TMP-SMX, or clarithromycin present a new approach for therapy. In vitro and animal studies have shown that such combinations may, in some cases, be superior to daptomycin monotherapy. In this paper we focus on the antibiotic combinations for complicated S. aureus infections.
Lister, Jessica L; Horswill, Alexander R
Staphylococcus aureus is a major cause of nosocomial and community-acquired infections and represents a significant burden on the healthcare system. S. aureus attachment to medical implants and host tissue, and the establishment of a mature biofilm, play an important role in the persistence of chronic infections. The formation of a biofilm, and encasement of cells in a polymer-based matrix, decreases the susceptibility to antimicrobials and immune defenses, making these infections difficult to eradicate. During infection, dispersal of cells from the biofilm can result in spread to secondary sites and worsening of the infection. In this review, we discuss the current understanding of the pathways behind biofilm dispersal in S. aureus, with a focus on enzymatic and newly described broad-spectrum dispersal mechanisms. Additionally, we explore potential applications of dispersal in the treatment of biofilm-mediated infections.
Mäder, Ulrike; Nicolas, Pierre; Depke, Maren
antisense RNAs not co-transcribed with other genes were found. Promoter analysis and comparison with Bacillus subtilis links the small number of antisense RNAs to a less profound impact of alternative sigma factors in S. aureus. Furthermore, we revealed that Rho-dependent transcription termination....... aureus HG001, a derivative of strain NCTC 8325, across experimental conditions ranging from optimal growth in vitro to intracellular growth in host cells. These data establish an extensive repertoire of transcription units and non-coding RNAs, a classification of 1412 promoters according...... to their dependence on the RNA polymerase sigma factors SigA or SigB, and allow identification of new potential targets for several known transcription factors. In particular, this study revealed a relatively low abundance of antisense RNAs in S. aureus, where they overlap only 6% of the coding genes, and only 19...
Barnes, Isabel J.; Bondi, Amedeo; Moat, Albert G.
Lysine biosynthesis in Staphylococcus aureus has been studied by use of a series of lysine auxotrophs. The strains were isolated after chemical mutagenesis. The majority of these mutant strains were classified according to the enzymatic step found to be deficient. Specific enzyme assays as well as nutritional tests were used to group the organisms. The enzymes included were dihydrodipicolinate synthetase, dihydrodipicolinate reductase, diaminopimelate epimerase, and diaminopimelate decarboxylase. The accumulation of diaminopimelate in certain mutants and the demonstration of dihydrodipicolinate synthetase and reductase provide the first detailed evidence that S. aureus utilizes the diaminopimelate pathway for lysine biosynthesis. A cell-free system was used to study the regulation of these enzymes with the exception of diaminopimelate epimerase. Lysine repressed all of the enzymes tested. The repression appeared to be coordinate in nature. The data presented provide suggestive evidence that the lysine biosynthetic region in S. aureus constitutes an operon. PMID:5802602
Full Text Available Estuda-se a contaminação por S. aureus do leite a ser pasteurizado, demonstrando que está altamente contaminado. São discutidas as conseqüências que a contaminação pode ter e conclui-se serem necessárias medidas urgentes para alterar a estrutura epidemiológica da "linha de leite".The present paper is a study on Staphylococcal contamination of milk before pasteurizing. Gross contamination is shown, and possible consequences are discussed. That measures intended to alter the epidemiologic structure of the so called milk line are necessary and urgent, is the final conclusion of the paper.
Padmapriya P Banada
Full Text Available Rapid detection of bloodstream infections (BSIs can be lifesaving. We investigated the sample processing and assay parameters necessary for highly-sensitive detection of bloodstream bacteria, using Staphylococcus aureus as a model pathogen and an automated fluidic sample processing-polymerase chain reaction (PCR platform as a model diagnostic system.We compared a short 128 bp amplicon hemi-nested PCR and a relatively shorter 79 bp amplicon nested PCR targeting the S. aureus nuc and sodA genes, respectively. The sodA nested assay showed an enhanced limit of detection (LOD of 5 genomic copies per reaction or 10 colony forming units (CFU per ml blood over 50 copies per reaction or 50 CFU/ml for the nuc assay. To establish optimal extraction protocols, we investigated the relative abundance of the bacteria in different components of the blood (white blood cells (WBCs, plasma or whole blood, using the above assays. The blood samples were obtained from the patients who were culture positive for S. aureus. Whole blood resulted in maximum PCR positives with sodA assay (90% positive as opposed to cell-associated bacteria (in WBCs (71% samples positive or free bacterial DNA in plasma (62.5% samples positive. Both the assays were further tested for direct detection of S. aureus in patient whole blood samples that were contemporaneous culture positive. S. aureus was detected in 40/45 of culture-positive patients (sensitivity 89%, 95% CI 0.75-0.96 and 0/59 negative controls with the sodA assay (specificity 100%, 95% CI 0.92-1.We have demonstrated a highly sensitive two-hour assay for detection of sepsis causing bacteria like S. aureus directly in 1 ml of whole blood, without the need for blood culture.
Kao, C T; Frazier, W C
Cultures of lactic acid bacteria, mostly from foods, were tested for their effect on the growth of Staphylococcus aureus in Trypticase Soy Broth (BBL). Some of the effectors, e.g., Streptococcus faecalis, S. faecium, Lactobacillus lactis, L. brevis, and Leuconostoc mesenteroides, stimulated growth of S. aureus during early hours of growth, especially at higher temperatures of incubation, but most cultures were inhibitory, and some (S. faecium and L. mesenteroides) were even killing by the time of attainment of the maximal phase of growth of the Staphylococcus. Low-temperature meat lactobacilli and Leuconostoc dextranicum inhibited S. aureus at 10, 15, 20, and 25 C throughout its growth. Streptococcus faecalis var. liquefaciens inhibited at these temperatures and at 30 and 37 C, as well. When the ratio of effectors to staphylococci in the inoculum was 100:1, the three enterococci, the meat Lactobacillus, and L. dextranicum prevented the attainment of 5 x 10(6) staphylococci per milliliter at 15 C, and all but the meat Lactobacillus did so at 22 C. A ratio of 1:1 accomplished similar results at 15 C, except that S. aureus was only delayed for 12 hr by S. faecalis. A ratio of 1:100 usually was ineffective. In general, the more effector bacteria there were in the inoculum, the greater was the overall inhibition (or stimulation) of S. aureus. Inhibition was most effective at 10 or 15 C, less so at 20 or 25 C, and least at 30 or 37 C, whereas stimulation during early growth was greater at the higher temperatures. Results with different strains of the effectors and with two strains of S. aureus were similar, for the most part.
Chen, C-J; Huang, Y-C
Not only is Asia the most populous region in the world, but inappropriate therapy, including self-medication with over-the-counter antimicrobial agents, is a common response to infectious diseases. The high antibiotic selective pressure among the overcrowded inhabitants creates an environment that is suitable for the rapid development and efficient spread of numerous multidrug-resistant pathogens. Indeed, Asia is among the regions with the highest prevalence rates of healthcare-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) and community-associated methicillin-resistant S. aureus (CA-MRSA) in the world. Most hospitals in Asia are endemic for multidrug-resistant methicillin-resistant S. aureus (MRSA), with an estimated proportion from 28% (in Hong Kong and Indonesia) to >70% (in Korea) among all clinical S. aureus isolates in the early 2010s. Isolates with reduced susceptibility or a high level of resistance to glycopeptides have also been increasingly identified in the past few years. In contrast, the proportion of MRSA among community-associated S. aureus infections in Asian countries varies markedly, from 35%. Two pandemic HA-MRSA clones, namely multilocus sequence type (ST) 239 and ST5, are disseminated internationally in Asia, whereas the molecular epidemiology of CA-MRSA in Asia is characterized by clonal heterogeneity, similar to that in Europe. In this review, the epidemiology of S. aureus in both healthcare facilities and communities in Asia is addressed, with an emphasis on the prevalence, clonal structure and antibiotic resistant profiles of the MRSA strains. The novel MRSA strains from livestock animals have been considered to constitute a public health threat in western countries. The emerging livestock-associated MRSA strains in Asia are also included in this review. © 2014 The Authors Clinical Microbiology and Infection © 2014 European Society of Clinical Microbiology and Infectious Diseases.
Ni Putu Ristiati
Full Text Available Forbazol E dapat disintesis dari 1-(p-tosil pirol-2-karbonil klorida dan fenasil amonium klorida dengan rendeman cukup tinggi melalui empat tahap reaksi yaitu : pertama, reaksi penggabungan; kedua, siklodehidrasi; ketiga,hidrolisis; dan keempat, klorinasi. Staphylococcus aureus merupakan bakteri gram positif. Untuk itu perlu diteliti : (a forbazol E dapat menghambat pertumbuhan S. aureus ; (b konsentrasi forbazol E 75 mg/L akan menimbulkan hambatan pertumbuhan S. aureus lebih tinggi dari konsentrasi 37,5 mg/L. Penelitian eksperimental ini menggunakan rancangan the randomized- posttest-only control group design dan melibatkan 9 sampel pada kelompok kontrol, 9 sampel pada kelompok perlakuan I dan 9 sampel pada perlakuan II. Data yang diperoleh dianalisis dengan menggunakan uji anova pada taraf signifikansi 5%. Hasil penelitian membuktikan forbazol E dapat menghambat pertumbuhan, pemberian forbazol E pada pada kelompok perlakuan II dengan konsentrasi 75 mg/L menimbulkan hambatan pertumbuhan S. aureus lebih tinggi dibandingkan dengan kelompok perlakuan I dengan konsentrasi 37,5 mg/L (p<0,05, uji lanjutan dengan uji beda nyata terkecil (BNT pada taraf signifikansi 5% diperoleh bahwa hambatan pertumbuhan S. aureus pada kelompok perlakuan II (75 mg/L berbeda bermakna dengan kelompok perlakuan I (37,5 mg/L (p<0,05. Bertolak dari pembahasan di atas dapat disimpulkan bahwa bioaktivitas forbazol E dapat menghambat pertumbuhan S. aureus.
Poonam Sood Loomba
Full Text Available S. aureus is the major bacterial cause of skin, soft tissue and bone infections, and one of the commonest causes of healthcare-associated bacteremia. Hospital-associated methicillin-resistant S. aureus (MRSA carriage is associated with an increased risk of infection, morbidity and mortality. Screening of high-risk patients at the time of hospital admission and decolonization has proved to be an important factor in an effort to reduce nosocomial transmission. The electronic database Pub Med was searched for all the articles on "Establishment of MRSA and the emergence of vancomycin-resistant S. aureus (VRSA." The search included case reports, case series and reviews. All the articles were cross-referenced to search for any more available articles. A total of 88 references were obtained. The studies showed a steady increase in the number of vancomycin-intermediate and vancomycin-resistant S. aureus. Extensive use of vancomycin creates a selective pressure that favors the outgrowth of rare, vancomycin-resistant clones leading to heterogenous vancomycin intermediate S. aureus hVISA clones, and eventually, with continued exposure, to a uniform population of vancomycin-intermediate S. aureus (VISA clones. However, the criteria for identifying hVISA strains have not been standardized, complicating any determination of their clinical significance and role in treatment failures. The spread of MRSA from the hospital to the community, coupled with the emergence of VISA and VRSA, has become major concern among healthcare providers. Infection-control measures, reliable laboratory screening for resistance, appropriate antibiotic prescribing practices and avoidance of blanket treatment can prevent long-term emergence of resistance.
Astrup, Lærke Boye; Iburg, Tine Moesgaard; Nielsen, Ole Lerberg
Introduction: Sepsis is a major problem in humans and both the incidence and mortality is increasing. Multiple microabcesses can be found in the brain of septic patients. Staphylococcus aureus is one of the most common causes of sepsis and brain abscesses. S. aureus is also a frequent cause...... pigs were kept as controls. The pigs were euthanized in groups of four at either 6, 12, 24 or 48 h post infection. The brain was collected from all the animals and examined histologically. Results: All the inoculated pigs developed sepsis and 7 out of 12 animals had microabscesses in the prosencephalon...
Full Text Available Chest pain is a common presenting symptom with a broad differential. Life-threatening cardiac and pulmonary etiologies of chest pain should be evaluated first. However, it is critical to perform a thorough assessment for other sources of chest pain in order to limit morbidity and mortality from less common causes. We present a rare case of a previously healthy 45 year old man who presented with focal, substernal, reproducible chest pain and Staphylococcus aureus bacteremia who was later found to have primary Staphylococcus aureus sternal osteomyelitis.
Katayama, Yuki; Baba, Tadashi; Sekine, Miwa; Fukuda, Minoru; Hiramatsu, Keiichi
Colonization by Staphylococcus aureus is a characteristic feature of several inflammatory skin diseases and is often followed by epidermal damage and invasive infection. In this study, we investigated the mechanism of skin colonization by a virulent community-acquired methicillin-resistant S. aureus (CA-MRSA) strain, MW2, using a murine ear colonization model. MW2 does not produce a hemolytic toxin, beta-hemolysin (Hlb), due to integration of a prophage, ϕSa3mw, inside the toxin gene (hlb). H...
Watkinson, M; Dyas, A
Two different neonatal umbilical cord treatment regimens were studied prospectively. Although a greater proportion of cords had separated by the seventh day in those babies not treated with topical antiseptics (47% vs. 26%), there was a significant excess (53% vs. 30%) of umbilical colonization by Staphylococcus aureus compared to those neonates whose cords were treated with alcohol wipes and hexachlorophane powder. The main purpose of treating cords is to prevent significant S. aureus colonization, and therefore current proposals to stop antiseptic treatment of umbilical cords should be disregarded.
Castro, S. L.; Ott, C. M.
The decreased gravity of the spaceflight environment creates quiescent, low fluid shear conditions. This environment can impart considerable effects on the physiology of microorganisms as well as their interactions with potential hosts. Using the rotating wall vessel (RWV), as a spaceflight analogue, the consequence of low fluid shear culture on microbial pathogenesis has provided a better understanding of the risks to the astronaut crew from infectious microorganisms. While the outcome of low fluid shear culture has been investigated for several bacterial pathogens, little has been done to understand how this environmental factor affects Staphylococcus aureus. S. aureus is an opportunistic human pathogen which presents a high level of infection risk to the crew, as it has been isolated from both the space shuttle and International Space Station. Given that approximately forty percent of the population are carriers of the bacteria, eradication of this organism from in flight environments is impractical. These reasons have lead to us to assess the response of S. aureus to a reduced fluid shear environment. Culture in the RWV demonstrated that S. aureus grown under the low-shear condition had lower cell concentrations after 10 hours when compared to the control culture. Furthermore, the low-shear cultured bacteria displayed a reduction in carotenoid production, pigments responsible for their yellow/gold coloration. When exposed to various environmental stressors, post low-shear culture, a decrease in the ability to survive oxidative assault was observed compared to control cultures. The low fluid shear environment also resulted in a decrease in hemolysin secretion, a staphylococcal toxin responsible for red blood cell lysis. When challenged by the immune components present in human whole blood, low-shear cultured S. aureus demonstrated significantly reduced survival rates as compared to the control culture. Assays to determine the duration of these alterations
Seidl, K.; Goerke, C; Wolz, C; Mack, D; Berger-Bächi, B; Bischoff, M
Biofilm formation in Staphylococcus aureus under in vitro growth conditions is generally promoted by high concentrations of sugar and/or salts. The addition of glucose to routinely used complex growth media triggered biofilm formation in S. aureus strain SA113. Deletion of ccpA, coding for the catabolite control protein A (CcpA), which regulates gene expression in response to the carbon source, abolished the capacity of SA113 to form a biofilm under static and flow conditions, while still all...
Collins, James; Buckling, Angus; Massey, Ruth C.
We examined the ability of 206 clinical isolates of Staphylococcus aureus to lyse T cells and found differences between Agr groups. We found that the beta and delta hemolysins are involved and that methicillin-resistant S. aureus strains are less toxic than methicillin-susceptible S. aureus strains.
Rasmussen, Rasmus V; Snygg-Martin, Ulrika; Olaison, Lars
The aim of this study was to investigate in-hospital mortality and 12-month mortality in patients with coagulase-negative Staphylococcus (CoNS) compared to Staphylococcus aureus (S. aureus) infective endocarditis (IE). We used a prospective cohort study of 66 consecutive CoNS and 170 S. aureus IE...
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...
Manenschijn, L.; Jetten, A.M.; Wamel, W.J.B. van; Tavakol, M.; Koper, J.W.; Akker, E.L.T. van den; Belkum, A. van; Rossum, E.F.C. van
Staphylococcus aureus (S. aureus) colonizes the anterior nares in part of the population and the persistent carrier state is associated with increased infection risk. Knowledge concerning the determinants of S. aureus nasal carriage is limited. Previously, we found that glucocorticoid receptor
Orth, H.; Salaam-Dreyer, Z.; Makgotlho, E.; Sinha, B.; Wasserman, E.
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
Plasmid profile of multi antibiotic resistant staphylococcus aureus isolated from diabetic wounds from patients at Nsukka, South-eastern, Nigeria. ... not susceptible to current antibiotics. This could suggest an imminent change in resistant pattern as observed, particularly in an area already reported as high antibiotic use.
Aim: This study was to determine the virulence encoding genes, and the antibiotic resistance patterns of the Staphylococcus aureus isolates, which were isolated from the nasal samples of chest clinic patients. Materials and Methods: The nasal samples of the in‑patients (431) and out‑patients (1857) in Kayseri Training and ...
Dec 30, 2014 ... Aim: This study was to determine the virulence encoding genes, and the antibiotic resistance patterns of the. Staphylococcus aureus isolates, which were isolated from the nasal samples of chest clinic patients. Materials and Methods: The nasal samples of the in‑patients (431) and out‑patients (1857) in ...
Food handlers have been recognized to play a major role in the transmission of food borne diseases; contributing significantly to the global incidence and burden of the diseases. This study therefore, assesses the nasal carriage of staphylococcus aureus among food handlers and restaurant workers in Ekpoma, Edo State, ...
36 samples of beans pudding from selected sources were analysed for Staphylococcus aureus and Bacillus cereus using standard protocols aimed at assessing its bacteriological quality. Samples obtained from restaurant showed slightly lower value for total plate count (1.3 x 104 - 1.6 x 106 cfu/gm) compared to samples ...
David B Friedman
Full Text Available Staphylococcus aureus pathogenesis is significantly influenced by the iron status of the host. However, the regulatory impact of host iron sources on S. aureus gene expression remains unknown. In this study, we combine multivariable difference gel electrophoresis and mass spectrometry with multivariate statistical analyses to systematically cluster cellular protein response across distinct iron-exposure conditions. Quadruplicate samples were simultaneously analyzed for alterations in protein abundance and/or post-translational modification state in response to environmental (iron chelation, hemin treatment or genetic (Deltafur alterations in bacterial iron exposure. We identified 120 proteins representing several coordinated biochemical pathways that are affected by changes in iron-exposure status. Highlighted in these experiments is the identification of the heme-regulated transport system (HrtAB, a novel transport system which plays a critical role in staphylococcal heme metabolism. Further, we show that regulated overproduction of acidic end-products brought on by iron starvation decreases local pH resulting in the release of iron from the host iron-sequestering protein transferrin. These findings reveal novel strategies used by S. aureus to acquire scarce nutrients in the hostile host environment and begin to define the iron and heme-dependent regulons of S. aureus.
Kromrey, M L; Göhler, A; Friedrich, N
To establish a routine workflow for in vivo magnetic resonance imaging (MRI) of mice infected with bacterial biosafety level 2 pathogens and to generate a mouse model for systemic infection with Staphylococcus aureus suitable for monitoring by MRI. A self-contained acrylic glass animal bed...
N. van Leeuwen; M. Heck; A.F. van Belkum (Alex); H.A. Verbrugh (Henri); W.B. van Leeuwen (Willem); J. van der Velden (Jos)
textabstractMost of the DNA-based methods for genetic typing of Staphylococcus aureus strains generate complex banding patterns. Therefore, we have developed a binary typing procedure involving strain-differentiating DNA probes which were generated on the basis of
Full Text Available A 29-year-old woman presented to the Fondazione IRCCS “Cà Granda” Ospedale Maggiore, a tertiary care university hospital in Milan (Italy, with skin lesions, fever, myalgia, joint pain and swelling, and a one-week history of low back pain. The diagnosis was Staphylococcus aureus (S. aureus bacteraemia spreading to skin, bones, and joints and a lumbosacral epidural abscess L5-S2. Neither initial focus nor predisposing conditions were apparent. The antibiotic therapy was prolonged for six-weeks with the resolution of fever, skin lesions, articular inflammation, and the epidural abscess. Community-acquired S. aureus infections can affect patients without traditional healthcare-associated risk factors, and community acquisition is a risk-factor for the development of complications. Raised awareness of S. aureus bacteraemia, also in patients without healthcare-associated risk factors, is important in the diagnosis, management, and control of this infection, because failure to recognise patients with serious infection and lack of understanding of empirical antimicrobial selection are associated with a high mortality rate in otherwise healthy people.
Mernelius, S; Carlsson, E; Henricson, J; Löfgren, S; Lindgren, P-E; Ehricht, R; Monecke, S; Matussek, A; Anderson, C D
Knowledge on Staphylococcus aureus colonization rates and epidemiology in hand eczema is limited. The aim of this study was to clarify some of these issues. Samples were collected by the "glove juice" method from the hands of 59 patients with chronic hand eczema and 24 healthy individuals. Swab samples were taken from anterior nares and throat from 43 of the 59 patients and all healthy individuals. S. aureus were spa typed and analysed by DNA-microarray-based genotyping. The extent of the eczema was evaluated by the hand eczema extent score (HEES). The colonization rate was higher on the hands of hand eczema patients (69 %) compared to healthy individuals (21 %, p eczema (HEES ≥ 13) had a significantly higher S. aureus density on their hands compared to those with milder eczema (HEES = 1 to 12, p = 0.004). There was no difference between patients and healthy individuals regarding colonization rates in anterior nares or throat. spa typing and DNA-microarray-based genotyping indicated certain types more prone to colonize eczematous skin. Simultaneous colonization, in one individual, with S. aureus of different types, was identified in 60-85 % of the study subjects. The colonization rate and density indicate a need for effective treatment of eczema and may have an impact on infection control in healthcare.
Interestingly, microbial resistance was higher for Ampicillin than Methicillin, while Tetracycline, among other antibiotics, was the most effective to both ear and nose isolates. Thus, the treatment for Staphylococcus aureus with Methicillin and other related antibiotics should be limited or controlled by susceptibility test results.
The survival or inhibition of foodborne pathogens in different fermented products are well documented. This prompted the study to evaluate survival of Esherichia coli O157:H7, Staphylococcus aureus, Shigella flexneri and Salmonella spp. in two Ethiopian traditional fermented low-alcohol beverages, Shamita and Borde.
Saad B. Almasaudi
Full Text Available Honey exhibits antimicrobial activities against a wide range of bacteria in different milieu. This study aims to compare the effects of five types of honey (both imported and local Saudi honey against Staphylococcus aureus. The five types of honey (Manuka Honey UMF +20, Manuka Honey UMF +16, Active +10 Manuka Honey, Sidr honey and Nigella sativa honey were evaluated for their bactericidal/bacteriostatic activities against both methicillin resistant and sensitive S. aureus. The inhibitory effect of honey on bacterial growth was evident at concentrations of 20% and 10% (v/v. Manuka Honey showed the best results. Manuka Honey UMF +20 had a bactericidal effect on both methicillin resistant and sensitive S. aureus. However, Sidr and N. sativa honey exerted only a bacteriostatic effect. The efficacy of different types of honey against S. aureus was dependent on the type of honey and the concentration at which it was administered. Manuka Honey had the best bactericidal activity. Future experiments should be conducted to evaluate the effects of honey on bacterial resistance.
Kobayashi, Tetsuro; Glatz, Martin; Horiuchi, Keisuke; Kawasaki, Hiroshi; Akiyama, Haruhiko; Kaplan, Daniel H; Kong, Heidi H; Amagai, Masayuki; Nagao, Keisuke
Staphylococcus aureus skin colonization is universal in atopic dermatitis and common in cancer patients treated with epidermal growth factor receptor inhibitors. However, the causal relationship of dysbiosis and eczema has yet to be clarified. Herein, we demonstrate that Adam17(fl/fl)Sox9-(Cre) mice, generated to model ADAM17-deficiency in human, developed eczematous dermatitis with naturally occurring dysbiosis, similar to that observed in atopic dermatitis. Corynebacterium mastitidis, S. aureus, and Corynebacterium bovis sequentially emerged during the onset of eczematous dermatitis, and antibiotics specific for these bacterial species almost completely reversed dysbiosis and eliminated skin inflammation. Whereas S. aureus prominently drove eczema formation, C. bovis induced robust T helper 2 cell responses. Langerhans cells were required for eliciting immune responses against S. aureus inoculation. These results characterize differential contributions of dysbiotic flora during eczema formation, and highlight the microbiota-host immunity axis as a possible target for future therapeutics in eczematous dermatitis. Copyright © 2015 Elsevier Inc. All rights reserved.
... 3.11 and 1.93 mg/l NH3 at 1, 8, 12, 16 and 20 ppt of salinities, respectively. The results of this study indicate that using brackish water for blue tilapia culture may not be a single factor to reduce the toxicity of high ammonia. Keywords: Oreochromis aureus, blue tilapia, ammonia, salinity. African Journal of Biotechnology, ...
Michelle E. Mulcahy
Full Text Available Nasal carriage of Staphylococcus aureus is a significant risk factor for secondary staphylococcal pneumonia in influenza A virus (IAV-infected hosts. However, little research has been undertaken to define the environmental and physiological changes that cause S. aureus to shift from commensal to pathogenic organism in this setting. The ability of virus-driven danger signals to cause S. aureus to transition from commensalism to pulmonary infection was explored in a recent study by Reddinger et al. R. M. Reddinger, N. R. Luke-Marshall, A. P. Hakansson, and A. A. Campagnari, mBio 7(6:e01235-16, 2016, http://dx.doi.org/10.1128/mBio.01235-16. The authors report that physiological host changes, including febrile temperature and a combination of host stress response signals, caused S. aureus biofilms to disperse from the nasal environment and cause active pulmonary infection. This commentary discusses the new finding in light of the current understanding of the mechanisms behind staphylococcal coinfection with IAV. In addition, it considers the mechanisms behind staphylococcal dispersal in this model. Overall, the study indicates that interkingdom signaling may occur following IAV infection and this likely contributes to sensitizing the IAV-infected host to secondary staphylococcal pneumonia.
This colonization was less important in lesional psoriatic skin (3%) than in non lesional psoriatic skin (12.1%) p= 0.20. Nasal screening identified (7/33) 21, 21% S. aureus carriers in psoriasis group and in control group. Our results are in consensus withliterature findings. They have confirmed the importance of antimicrobial ...
This paper investigates the incidence of the bacterial organism Staphylococcus, aureus in locally produced fresh milk (nono). The fresh milk was obtained from the Damaturu main market, Yobe state of Nigeria. Petri dishes were washed and allowed to dry. They were then sterilized in hot air oven at 130°C for two hours and ...
Hallin, Marie; Friedrich, Alexander W; Struelens, Marc J; Caugant, Dominique A.
The spa typing method is based on sequencing of the polymorphic X region of the protein A gene (spa), present in all strains of Staphylococcus aureus. The X region is constituted of a variable number of 24-bp repeats flanked by well-conserved regions. This single-locus sequence-based typing method
Surveys conducted in Senegal have shown a strong association of staphylococci with subclinical mastitis in dairy cows. This study aimed to characterise Staphylococcus aureus strains identified in the dairy farms in Dakar. Of a total of 244 Staphylococcus spp isolates col ected from 135 lactating cows with subclinical ...
H.F.L. Wertheim (Heiman); M.C. Vos (Margreet)
textabstractIn a retrospective study, Dr Muller and colleagues have assessed the efficacy of mupirocin nasal ointment alongside hygienic measures in methicillin-resistant Staphylococcus aureus (MRSA)-positive patients admitted to the intensive care unit (ICU). Their findings, which suggest that
Lerche, C. J.; Christophersen, L. J.; Trøstrup, H.
The empiric treatment of infective endocarditis (IE) varies widely and, in some places, a regimen of penicillin in combination with an aminoglycoside is administered. The increasing incidence of Staphylococcus aureus IE, poor tissue penetration by aminoglycosides and low frequency of penicillin...
Pérez, M Guadalupe; Castro, Graciela; Mansilla, Celeste; Kaldzielski, Carina; Salas, Gisela; Rosanova, María Teresa; Berberian, Griselda
Orbital cellulitis typically occurs in older children, but it can occasionally affect infants and neonates. Staphylococcus aureus is the main pathogen isolated. Outcome depends on an adequate initial approach. We report three neonates with orbital cellulitis caused by community-associated MRSA.
Mucins act as protection for the gastrointestinal tract against various invading organisms. They are also crucial in developing drugs against these organisms as well as other therapeutic purposes. This study was carried out to investigate the binding of Staphylococcus aureus onto bovine intestinal mucin in vitro. The isolate ...
Swinkels, J. M.; Cox, P.; Schukken, Y. H.; Lam, T. J G M|info:eu-repo/dai/nl/14686820X
Clinical Staphylococcus aureus mastitis is difficult to cure. Extended antimicrobial treatment is often advocated as a practical approach to improve cure rates; however, scientific evidence of this hypothesis is lacking. A multi-centered, nonblinded, randomized, positive-controlled clinical trial