Broad-Spectrum Cephalosporin-Resistant <i>Klebsiella</i> spp. Isolated from Diseased Horses in Austria

Abstract

The aim of the present study was to investigate the diversity of broad-spectrum cephalosporin-resistant <i>Klebsiella</i> spp. isolated from horses in Austria that originated from diseased horses. A total of seven non-repetitive cefotaxime-resistant <i>Klebsiella</i> sp. isolates were obtained during diagnostic activities from autumn 2012 to October 2019. Antimicrobial susceptibility testing was performed. The isolates were genotyped by whole-genome sequencing (WGS). Four out of seven <i>Klebsiella</i> isolates were identified as <i>K. pneumoniae</i>, two as <i>K. michiganensis</i> and one as <i>K. oxytoca</i>. All isolates displayed a multi-drug resistant phenotype. The detection of resistance genes reflected well the phenotypic resistance profiles of the respective isolates. All but one isolate displayed the extended-spectrum &#946;-lactamases (ESBL) phenotype and carried CTX-M cefotaximases, whereas one isolate displayed an ESBL and AmpC phenotype and carried cephamycinase (CMY)-2 and sulfhydryl variable (SHV)-type b and Temoniera (TEM) &#946;-lactamases. Among <i>Klebsiella pneumoniae</i> isolates, for different sequence types (ST) could be detected (ST147, ST307, ST1228, and a new ST4848). Besides resistance genes, a variety of virulence genes, including genes coding for yersiniabactin were detected. Considering the high proximity between horses and humans, our results undoubtedly identified a public health issue. This deserves to be also monitored in the years to come.