High Fecal Prevalence of -Positive in Veal Calves at Slaughter in France.

The aim of this study was to determine the percentage of healthy veal calves carrying -positive strains at the time of slaughter in France. Fecal samples were selectively screened for -positive isolates using media supplemented with colistin. Screening for genes was also carried out in isolates resistant to critically important antimicrobials used in human medicine recovered from the same fecal samples. Overall, 28 (16.5%) out of the 170 veal calves tested carried -positive . As some calves carried several non-redundant -positive strains, 41 -positive were recovered. Thirty-one and seven strains were positive for and genes, respectively, while no strain was positive for the gene. Co-carriage of and was identified in three strains. All -positive isolates, except one, were multidrug-resistant, with 56.1% being ciprofloxacin-resistant and 31.7% harboring genes. All -positive carried genes, mainly . This study highlights the high prevalence of -positive strains in feces of veal calves at the time of slaughter. It also points out the multidrug (including ciprofloxacin) resistance of such strains and the co-occurrence of genes with genes.