Objectives: Our objectives were to study the prevalence, risk factors for carriage and transmission dynamics of ESBL-producing Enterobacteriaceae (ESBLPE) in a national survey of cattle.
Methods: This was a point-prevalence study conducted from July to October 2013 in Israel. Stool samples from individual cows were collected. Molecular typing was done by REP-PCR.
Results: The study included 1226 cows in 123 sections in 40 farms. ESBLPE were identified in 291 samples (23.7%): 287 E. coli and 4 K. pneumoniae. The number of ESBLPE-positive cows was highest in quarantine stations and fattening farms and was lowest in pasture farms (p=0.03). The number of ESBLPE-positive cows was lowest in sections containing adult cows (>25 months) and highest in calves (E. coli isolates were typed into 106 REP-PCR types, harboring mostly blaCTX-M-1 or blaCTX-M-9 group genes. Most REP-PCR types were identified in ≥2 isolates. Fourteen REP-PCR types were identified in more than 1 farm, with only 6 of the farms adjacent to each other.
Conclusions: The prevalence of ESBLPE carriage is high in calves in cowsheds where the use of antimicrobial prophylaxis, lack of cleaning and crowding are common. ESBLPE disseminate within cowsheds mainly by clonal spread, with limited inter-cowshed transmission.
