Subtype Analysis of Salmonella Isolated from Subclinically Infected Dairy Cattle and Dairy Farm Environments Reveals the Presence of Both Human- and Bovine-Associated Subtypes
| Autor: | Mara Elton, Kevin J. Cummings, Martin Wiedmann, Lorraine D. Rodriguez-Rivera, Emily M. Wright, Julie D. Siler, Lorin D. Warnick |
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| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Serotype
Salmonella New York Cattle Diseases Microbial Sensitivity Tests Biology medicine.disease_cause Microbiology Article Antibiotic resistance medicine Pulsed-field gel electrophoresis Environmental Microbiology Animals Humans Serotyping Dairy cattle Phylogeny General Veterinary business.industry General Medicine Biodiversity Subtyping Anti-Bacterial Agents Electrophoresis Gel Pulsed-Field Dairying Salmonella Infections Livestock Cattle business |
| Popis: | While it is well established that clinically ill livestock represent a reservoir of Salmonella, the importance of subclinical shedders as sources of human salmonellosis is less well defined. The aims of this study were to assess the subtype diversity of Salmonella in healthy dairy cattle and associated farm environments and to compare the subtypes isolated from these sources with the Salmonella subtypes associated with clinical human cases in the same geographic area. A total of 1,349 Salmonella isolates from subclinical dairy cattle and farm environments (46 farms) were initially characterized by traditional or molecular serotyping and tested for antimicrobial susceptibility. A set of 381 representative isolates was selected for further characterization by pulsed-field gel electrophoresis (PFGE); these isolates represented unique combinations of sampling date, serovar, antimicrobial resistance pattern, farm of origin, and source, to avoid overrepresentation of subtypes that were re-isolated from a given source. These 381 isolates represented 26 Salmonella serovars; the most common serovars were Cerro [(38.8%, 148/381) isolated from 21 farms], Kentucky [16.3%; 10 farms], Typhimurium [9.4%; 7 farms], Newport [7.6%; 8 farms], and Anatum [6.3%; 6 farms]. Among the 381 isolates, 90 (23.6%) were resistant to between 1 and 11 antimicrobial agents, representing 50 different antimicrobial resistance patterns. Overall, 61 XbaI-PFGE types were detected among these 381 isolates, indicating considerable Salmonella diversity on dairy farms without evidence of clinical salmonellosis. Fourteen PFGE types, representing 12 serovars, exactly matched PFGE types from human isolates, suggesting that subclinically infected dairy cattle could be sources of human disease-associated Salmonella. |
| Databáze: | OpenAIRE |
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