Evidence of potentially unrelated AmpC beta-lactamase producing Enterobacteriaceae from cattle, cattle products and hospital environments commonly harboring the blaACC resistance determinant

The occurrence and genetic relatedness of AmpC beta-lactamase producing Enterobacteriaceae isolated from clinical environments, groundwater, beef, human and cattle faeces were investigated. One hundred seventy-seven (177) samples were collected and cultured on MacConkey agar. A total of 203 non-repetitive isolates were characterised using genus/species-specific PCRs and the identified isolates were subjected to antibiotic susceptibility testing. The production of AmpC beta-lactamases was evaluated using cefoxitin disc, confirmed by the D96C detection test and their encoding genes detected by PCR. The D64C extended-spectrum beta-lactamases (ESBL) test was also performed to appraise ESBLs/AmpC co-production. The genetic fingerprints of AmpC beta-lactamase producers were determined by ERIC-PCR. A total of 116 isolates were identified as E . coli ( n = 65), Shigella spp. ( n = 36) and Klebsiella pneumoniae ( n = 15). Ciprofloxacin resistance (44.4–55.4%) was the most frequent and resistance against the Cephem antibiotics ranged from 15–43.1% for E . coli , 25–36.1% for Shigella spp., and 20–40% for K . pneumoniae . On the other hand, these bacteria strains were most sensitive to Amikacin (0%), Meropenem (2.8%) and Piperacillin-Tazobactam (6.7%) respectively. Nineteen (16.4%) isolates comprising 16 E . coli and 3 Shigella spp. were confirmed as AmpC beta-lactamase producers. However, only E . coli isolates possessed the corresponding resistance determinants: bla ACC (73.7%, n = 14), bla CIT (26%, n = 5), bla DHA (11%, n = 2) and bla FOX (16%, n = 3). Thirty-four (27.3%) Enterobacteriaceae strains were confirmed as ESBL producers and a large proportion (79.4%, n = 27) harboured the bla TEM gene, however, only two were ESBLs/AmpC co-producers. Genetic fingerprinting of the AmpC beta-lactamase-producing E . coli isolates revealed low similarity between isolates. In conclusion, the findings indicate the presence of AmpC beta-lactamase-producing Enterobacteriaceae from cattle, beef products and hospital environments that commonly harbour the associated resistance determinants especially the bla ACC gene, nonetheless, there is limited possible cross-contamination between these environments.