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
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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