b; Kimron Veterinary Institute, Beit Dagan, Israel c Our objectives were to study the prevalence, risk factors for carriage, and transmission dynamics of extended-spectrum-␤-lactamase (ESBL)-producing Enterobacteriaceae (ESBLPE) in a national survey of cattle. This was a point prevalence study conducted from July to October 2013 in Israel. Stool samples were collected from 1,226 cows in 123 sections on 40 farms of all production types. ESBLPE were identified in 291 samples (23.7%): 287 contained Escherichia coli and 4 contained Klebsiella pneumoniae. The number of ESBLPE-positive cows was the highest in quarantine stations and on fattening farms and was the lowest on pasture farms (P ‫؍‬ 0.03). The number of ESBLPE-positive cows was the lowest in sections containing adult cows (age, >25 months) and highest in sections containing calves (age, <4 months) (P < 0.001). Infrastructure variables that were significant risk factors for ESBLPE carriage included crowding, a lack of manure cleaning, and a lack of a cooling (P < 0.001 for each), all of which were more common in sections containing calves. Antimicrobial prophylaxis was given almost exclusively to calves and was associated with a high number of ESBLPE carriers (P < 0.001). The 287 E. coli isolates were typed into 106 repetitive extragenic palindromic (REP)-PCR types and mostly harbored bla CTX-M-1 or bla CTX-M-9 group genes. The isolates on the six farms with >15 isolates of ESBLPE were of 4 to 7 different REP-PCR types, with one dominant type being harbored by about half of the isolates. Fourteen types were identified on more than one farm, with only six of the farms being adjacent to each other. The prevalence of ESBLPE carriage is high in calves in cowsheds where the use of antimicrobial prophylaxis is common. ESBLPE disseminate within cowsheds mainly by clonal spread, with limited intercowshed transmission occurring. Since the advent of the first antimicrobials, antimicrobial-resistant bacteria (AMRB) have spread in conjunction with the use of the respective antimicrobial agents (1). Accordingly, the emergence of extended-spectrum ␤-lactamase (ESBL) enzymes as a global threat followed the introduction of third-generation cephalosporins (TGC), used mainly in health care settings (2). Although the ESBLs were first noted in the 1980s, a substantial increase in their prevalence in Escherichia coli was noted in the 2000s. This increase was mainly related to the emergence of a pandemic clone, designated sequence type (ST) 131. A particular worrisome feature of this clone was its predominance in community-onset cases of infection with ESBL-producing bacteria (3). This epidemiologic feature has attracted attention to the possibility of sources of acquisition other than health care settings, including the food and livestock industries. Indeed, many studies have documented the presence of ESBL-producing bacteria in a variety of meats and other livestock-origin food samples. Although the use of antimicrobials has often been suggested to be the main culprit for this ...

The goal of this study was to compare the molecular features of bovine- and human community-acquired extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in Israel. Bovine ESBL-producing E. coli were isolated during a point-prevalence study from the main farming locations throughout Israel. Human ESBL-producing E. coli isolates were collected from community-acquired urinary tract infection cases. Molecular typing was done initially by repetitive extragenic palindromic-PCR. Representative isolates were subjected to next-generation sequencing (NGS) and analyzed for multilocus sequence typing (MLST), core genome MLST (cgMLST), bla gene allele, and mobile genetic elements (MGEs) surrounding it. Out of the 287 bovine- and 104 community-derived ESBL-producing E. coli isolates, 44 and 26 isolates were subjected to NGS, respectively. Both populations exhibited a diverse but distinct clonal structure with predominance of several sequence types (STs); two clones, ST-10/167 (n = 13) and ST-38 (n = 8), were present. cgMLST analysis of these clones revealed that the majority of isolates exhibited phylogenetic distance (PD) of >178 gene difference from their closest isolate, with the exception of five isolates that exhibited PD of <24 gene difference, including two bovine- to three community-derived isolates. Hence, clonal transmission of ESBL-producing E. coli between cattle and the community, although uncommon, is likely to have occurred. The bla gene was identified in 52/70 (74%) isolates from both cattle and the community and was surrounded by MGEs that were composed mostly of either the Tn3 or IS1380 families. Thus, MGEs are likely to play an important role in the exchange of resistance genes.

Our objectives were to establish a methodology for surveillance of ciprofloxacin-resistant Enterobacteriaceae and gentamicin-resistant Enterobacteriaceae (CPRE and GNRE, respectively) in cattle and to study the prevalence and risk factors for carriage of these bacteria in a national survey. This was a point prevalence study conducted from July to October 2013 in Israel. Stool samples were collected from 1,226 cows in 123 sections of 40 farms of all production types. The number of CPRE- and GNRE-positive cows was highest in quarantine stations and fattening farms and was lowest in pasture farms (p < 0.01). The number of CPRE- and GNRE-positive cows was lowest in dairy farm sections containing adult cows (>25 months) and highest in calves (<4 months) (p < 0.001). In bivariate analysis, other variables that were significant risk factors for CPRE and GNRE carriage included fewer troughs, crowding, lack of manure cleaning, and recent arrival of new calves. Antimicrobial prophylaxis was given almost exclusively to calves and was associated with a higher prevalence of carriers (p < 0.001). Compared to the use of nonselective media (MacConkey agar alone), the use of selective media (MacConkey agar with 10 μg/ml of ciprofloxacin or 5 μg/ml of gentamicin) increased the sensitivity of screening for CPRE and GNRE by 6.6- and 13.5-fold, respectively. CPRE and GNRE were identified in 609 (49.7%) and 840 (68.5%) samples, respectively. This study provides novel data regarding both the epidemiology of CPRE and GNRE carriage in livestock and the microbiological methodology for their surveillance.

Klement E, Schwaber MJ, Carmeli Y. 2016. Correction for Adler et al., Prevalence, risk factors, and transmission dynamics of extended-spectrum-␤-lactamaseproducing Enterobacteriaceae: a national survey of cattle farms in Israel in 2013.