High Frequency of Multidrug-Resistant (MDR) Atypical EnteropathogenicEscherichia coli(aEPEC) in Broilers in Hungary

Escherichia coli(EC) strains belong to several pathotypes capable of infecting both humans and animals. Some of them have zoonotic potential and can sporadically cause epidemic outbreaks. Our aim was to screen for the distribution of these pathotypes in broilers and their related products. Therefore,E. colistrains were isolated (n= 118) from poultry intestine (n= 57), carcass (n= 57), and wastewater (n= 4) samples from one slaughterhouse with own reared poultry source and the National Reference Laboratory (NRL) poultryE. colicollection (n= 170) from the year 2017 was also studied. All 288E. colistrains were screened by PCR for pathotype-specific genesstx, eae, st-lt, aggR, ipaH, and for further EPEC-specific virulence genes (bfp, EAF, tir, perA, ler). Altogether 35 atypical enteropathogenicE. coli(aEPEC) strains from the slaughterhouse and 48 aEPEC strains from the NRL collection were found. Regarding the phylogenetic groups of aEPEC, all four main groups were represented but there was a shift toward the B2 group (25%) as compared with the non-EPEC isolates (3%). The aEPEC isolates belonged to serogroups O14, O108, and O45. Multidrug resistance (MDR) was abundant in aEPEC strains (80 out of 83 aEPEC) with a diverse resistance pattern (n= 56). Our results of this study indicate that the high frequency of aEPEC in broilers and on their carcass surface, with frequent MDR to several antibiotic groups, raises the possibility that these strains pose a zoonotic risk to humans.