Carriage of ESBL-Producing Enterobacterales in Urban and Rural Hooded Crows in Hungary.

BACKGROUND: Considering the increasing reports of antimicrobial resistance (AMR) in wildlife, highlighting its complexity, importance, and spread. We investigated the prevalence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales in the hooded crow. METHODS: Faecal samples were collected from 52 rural and 212 urban wild crows in Hungary, caught using ladder traps, and tested for ESBL presence. Bacterial species were identified using MALDI-TOF. Antibiotic susceptibility was tested using the disc diffusion method, and ESBL producers were detected based on double-disc synergy. ESBL-encoding genes were identified using PCR, and WGS was performed on isolated ESBL-producing E. coli (197/221 isolated ESBLs). RESULTS: Four of the sampled rural hooded crows and 130 urban ones (7.7% vs. 61%, chi-square p < 0.0001) yielded ESBL producers with the overwhelming dominance of E. coli. The blaCTX-M-1 group was predominant in both groups. In addition to CTX-M genes, genes encoding resistance to other antibiotic classes, such as APHs, sul genes, tet genes, etc, various virulence factors, and several incompatible plasmids were also detected. Most isolates belonged to the B1 and A phylogenetic groups. Overall, 22 sequence types (STs) and 33 distinct cgSTs were defined. The most prevalent ST was ST58, followed by ST10, S38, ST155, ST442, and more. CONCLUSIONS: The much higher carrier frequency among urban crows points to the role of anthropogenic sources in the emergence of ESBL producers. Hooded crows, due to their increasing presence in cities and proximity to humans, likely facilitate the dissemination of ESBL producers between the environment and humans.