Epidemiology and Genotypic Characteristics of Methicillin-Resistant Staphylococcus aureus Strains of Porcine Origin
Autor: | Paula J. Fedorka-Cray, Ping Wang, Bayleyegn Z. Molla, Megan Byrne, Wondwossen A. Gebreyes, Jennifer L. Mathews, Srinand Sreevatsan, Melanie Abley, Charlene R. Jackson |
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Rok vydání: | 2012 |
Předmět: |
Methicillin-Resistant Staphylococcus aureus
Microbiology (medical) Veterinary medicine Meat Genotype Swine Microbial Sensitivity Tests Biology Perineum medicine.disease_cause Staphylococcal infections Clinical Veterinary Microbiology Microbiology Bacterial Proteins Prevalence medicine Pulsed-field gel electrophoresis Animals Cluster Analysis Micrococcal Nuclease Penicillin-Binding Proteins Typing Ohio Molecular Epidemiology Molecular epidemiology SCCmec Broth microdilution food and beverages biochemical phenomena metabolism and nutrition Staphylococcal Infections bacterial infections and mycoses medicine.disease Methicillin-resistant Staphylococcus aureus Anti-Bacterial Agents Electrophoresis Gel Pulsed-Field Nasal Mucosa Carrier State Multilocus sequence typing Multiplex Polymerase Chain Reaction Multilocus Sequence Typing |
Zdroj: | Journal of Clinical Microbiology. 50:3687-3693 |
ISSN: | 1098-660X 0095-1137 |
Popis: | The main goal of this study was to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA), particularly livestock-associated MRSA (LA-MRSA) in pigs and pork. The genotypic relatedness of isolates on the farm, at slaughter, and at the retail level was assessed. Paired nasal and perianal swab samples were collected from 10 cohorts of market-age pigs (24 pigs per cohort) and carcasses at slaughterhouse, and pork samples were collected at retail. Staphylococci were isolated using selective enrichment method. Isolates were tested for antimicrobial resistance by broth microdilution. Duplex PCR was used to confirm MRSA using species-specific ( nuc ) and methicillin resistance ( mecA ) genes. The clonal relatedness of isolates was determined using pulsed-field gel electrophoresis (PFGE), Staphylococcus protein A ( spa ) typing, multilocus sequence typing (MLST), and staphylococcal cassette chromosome mec element (SCC mec ) typing. MRSA was detected in 5 of the 10 cohorts (50%), with the prevalence ranging from 0% to 12.5% per cohort. Of all the pigs sampled on the farm before they went to market, 3% (7/240) were MRSA positive. A higher prevalence of MRSA was detected at holding pens at the slaughterhouse (11% [27/240]). MRSA was also detected in 2% (4/235) of the carcasses and 4% (5/135) of the retail pork. While the isolates appear predominantly to be highly clonal, PFGE had a relatively higher discriminatory power (discriminatory index [DI] = 0.624). Four genotypic clusters were identified by PFGE; of the four clusters, clonal type B was predominant across the farm-to-retail continuum. MLST findings revealed that sequence type 5 (ST5) was the most predominant subtype (32/50). The livestock-associated MRSA (clonal complex 398 [CC398] or sequence type 398 [ST398]) was the second common type (12/50) and was detected at all stages from farm to retail. Nine of the 50 (18%) MRSA isolates belonged to spa type 539/t034 that were of ST398 based on MLST. The results of this study confirm that MRSA, including LA-MRSA, is common in herds of swine in Ohio and hereby shown to persist in the farm to processing and retail continuum. |
Databáze: | OpenAIRE |
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