Recovery of isolated from eggs and the commercial layer farms.

BACKGROUND

is recognized as a common bacterial cause of foodborne diarrheal illness worldwide, and animal or its food products have been the most common vehicles of the infections. This study aimed to investigate the distribution of in two commercial layer farms and to determine the genetic relatedness between these strains. The isolates were serotyped by slide agglutination using commercial antisera and analyzed for genetic relatedness using pulsed-field gel electrophoresis (PFGE).

RESULTS

The internal environment had the highest prevalence of (14/15, 93.3%), followed by external environment (60/96, 62.5%) and egg samples (23/84, 27.3%). The prevalence of in the environment was significantly higher than that in egg samples ( < 0.05). The occurrence of in the internal environment (93.3%) was relatively higher than in the external environment (55.6-77.2%). The 111 isolates were distributed among 15 PFGE types, and the PFGE results suggested that there existed cross-contamination between these strains not only from eggs, but also from the environments.

CONCLUSIONS

The findings indicated ongoing cross-contamination inside or outside of the layer farms, and that could also spread along the egg production line.