[ESBL-producing E. coli and EHEC in dogs and cats in the Tyrol as possible source of human infection]

Abstract

In contrast to infections with enterohaemorrhagic E. coli (EHEC), which are thought to be classical zoonosis, the zoonotic potential of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae is still widely unknown. The aim of our study was to determine the frequency of EHEC and ESBL-producing Enterobacteriaceae in domestic animals (dogs and cats) in the Tyrol. Among 228 fecal samples of dogs (n = 92) and cats (n = 136) three samples (1.3%) were positive in the EHEC-ELISA. In two of the three cases isolation of the organism was not possible, the third sample of a two-year-old crossbreed bitch yielded EHEC O103:H2. In twelve of 228 (5.3%) fecal samples 13 ESBL-producing Enterobacteriaceae (in ten cats and two dogs) were found.These animals mainly derived from homes for animals (ten animals, 83%). 75% of the isolates belonged to the CTX-M-1-group, 8% to the CTX-M-2-group and 17% to the CTX-M-9-group. One isolate was positive for CTX-M-1 and CTX-M-9. Typing of the 13 ESBL-producing isolates by multilocus sequence typing (MLST) showed ten different sequence types, which points out the importance of the horizontal transfer of mainly plasmid-coded ESBL genes. Transmission of EHEC and ESBL-producing Enterobacteriaceae from domestic animals to humans is possible, corroborated by the fact that the EHEC serotype found in one dog and the sequence types detected by MLST in several dogs and cats were previously reported to occur in severe human infection.