Molecular Diversity of Extended-Spectrum β-lactamase-producing Escherichia coli from vultures in Canary Islands.

Antimicrobial resistance among isolates from wild animals is increasingly reported. Extended-spectrum beta-lactamase (ESBL)-producingEnterobacteriaceae, and particularlyEscherichia coli, have spread worldwide as one of the most common multidrug-resistant organisms. The aim of this study was to determine the carriage rate of ESBL-producingE.coliisolates and their genetic characteristics in wild vultures from the Canary Islands. Faecal samples were collected from 22 apparently healthy free-ranging (wild) vulture chicks from Lanzarote and Fuerteventura (Canary Islands) during July 2019. They were seeded in MacConkey agar supplemented with cefotaxime (2 mu g ml(-1)). Colonies with typical morphology ofE.coliwere identified by MALDI-TOF-MS. Antimicrobial susceptibility was done by disk diffusion. Phenotypic detection of ESBL was performed by double-disk tests. The presence ofbla(CTX-M),bla(SHV),bla(TEM),bla(KPC)andbla(OXA-48)genes, as well asmcr-1 (colistin resistance),tetA/tetB andint1 gene, was tested by PCR/sequencing. Phylogenetic groups and multilocus sequence typing (MLST) were determined by PCR/sequencing. ESBL-producingE.coliisolates were detected in 5/22 tested animals (22.7%), and all isolates (one/animal) carriedbla(CTX-M)genes:bla(CTX-M-15)(n= 3) andbla(CTX-M-55)(n= 2). ESBL-positive isolates were ascribed to phylogenetic group D (two isolates), B-1(two isolates) and A (one isolate), and five sequence types were detected (ST/phylogenetic-group/ESBL): ST515/B1/CTX-M-15, ST1290/A/CTX-M-15, ST38/D/CTX-M-15, ST457/D/CTX-M-55 and ST6448/B-1/CTX-M-55; this suggests a genetic diversity among these isolates. Three CTX-M-15-producing isolates contained thebla(TEM)gene and one thetetA gene. To our knowledge, this appears to be the first report of ESBL-producingE.coliin vulture chicks from the Canary Islands.