ESBLs-producing Escherichia coli from Sheep-origin: Genome-Wide Virulence Genes Identification and In Vivo Virulence Assessment in Mice and Galleria mellonella.

TLDR: This study investigates the presence of virulence genes in third-generation cephalosporin (3GC)-resistant E. coli strains from sheep anal swabs in northwest China and indicates an important first step for a comprehensive characterization of pathogenicity and zoonotic potential of sheep-origin ESBLs-producing E coli.

Abstract: The worldwide spread of pathogenic Escherichia coli, together with the multi-drug resistant linked with extended-spectrum β-lactamases (blaCTX-M , blaTEM and blaOXA ) not only affect the health of animals and humans but also bring huge economic losses to animal husbandry. Despite the high levels of virulence present in many ESBLs-producing E. coli isolates, however, few studies have comprehensively assessed the pathogenicity of ESBLs-producing E. coli isolates. Thus, the aim of the present study was to investigate the presence of virulence genes in third-generation cephalosporin (3GC)-resistant E. coli and to assess their pathogenicity and zoonotic potential. Previously, we identified 67 ESBLs-producing E. coli strains from sheep anal swabs in northwest China. In this study, we genotypically and phenotypically characterized isolates of E. coli that produce ESBLs. According to the Virulence-Finder and virulence factors database all ESBLs-producing E. coli strains harbored a wide range of virulence genes. The ColV plasmid-related genes (hlyF, ompT, iss, iutA, and cvaC) were present in 52 (77.6%) ESBLs-producing E. coli isolates. Surprisingly, quite a number of ExPEC virulence-related genes were detected in 62 (92.5%) of 67 isolates. A total of 33 serotypes and 37 ST types were found in 67 ESBLs-producing isolates. ST10 is the most prevalent ST, which is represented by 5 strains. The cluster analysis showed that CC10 and CC23 were the common clonal complexes (CCs). Predominant serotypes were O8 (10%) and O9 (9%) followed by 6% each of O89, O101 and O185. Most sheep-origin ESBLs-producing E. coli held the highly pathogenic to human and displayed moderate- to vigorous-intensity motor capacity. The ESBLs-producing E. coli isolates with numerous virulence-related genes were able to cause multiple infectious diseases in animal models (mice, neonatal rats and Galleria mellonella). To our knowledge, this study represents an important first step for a comprehensive characterization of pathogenicity and zoonotic potential of sheep-origin ESBLs-producing E. coli isolates. These findings may be of significant value for the identification of pathogenicity and zoonotic potential risks associated with sheep-origin ESBLs-producing E. coli. This article is protected by copyright. All rights reserved.