Short communication: Determination of Salmonella clustered regularly interspaced short palindromic repeats (CRISPR) diversity on dairy farms in Wisconsin and Minnesota.
J Dairy Sci
; 97(10): 6370-7, 2014 Oct.
Article
em En
| MEDLINE
| ID: mdl-25108866
ABSTRACT
Salmonella enterica ssp. enterica is a foodborne pathogen able to cause disease in both humans and animals. Diverse serovars of this pathogen exist, some of which are host specific, causing a range of clinical symptoms from asymptomatic infection through morbidity and mortality. According to a 2007 survey by the USDA National Animal Health Monitoring System, fecal shedding of Salmonella from healthy cows occurs on 39.7% of dairy farms in the United States. Certain serovars are frequently isolated from dairy farms and the majority of isolates from the National Animal Health Monitoring System study were represented by 5 serovars; however, genotypic diversity was not examined. The objective of this study was to determine the diversity of clustered regularly interspaced short palindromic repeats (CRISPR) loci in Salmonella collected from 8 dairy farms with a previous history of salmonellosis. None of the cows or calves sampled on 2 of the 8 dairy farms were shedding Salmonella, although Salmonella was detected in a cow bedding sample on 1 of these farms. Salmonella populations were discrete on each farm, according to CRISPR typing, with the exception of an Anatum var. 15+ type on farms 5 and 6 and the Montevideo type on farms 1 and 2. One to 4 distinct CRISPR genotypes were identified per farm. The CRISPR typing differed within serovars, as Montevideo, Anatum var. 15+, and Muenster serovars had no overlap of spacer content, even on the same farm, reflecting between- and within-serovar genetic diversity. The dynamic nature of Salmonella populations was shown in a farm that was sampled longitudinally over 13.5 mo. Changes in serovar from 3,19-z27 to Montevideo was observed between the first sampling time and 8 mo later, with concomitant change in CRISPR alleles. The results indicate that Salmonella strains present in smaller dairy herds (<500 head) are specific to that farm and new Salmonella strains may emerge over time.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Salmonella
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Intoxicação Alimentar por Salmonella
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Salmonelose Animal
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Variação Genética
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Doenças dos Bovinos
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Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas
Tipo de estudo:
Prognostic_studies
Limite:
Animals
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Female
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Humans
País como assunto:
America do norte
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article