Investigation article published in BMC Veterinary Research

October 21^st, 2024

Background
Clostridioides difficile has been recognized as an emerging pathogen in both humans and animals. In this context, antimicrobial resistance plays a major role in driving the spread of this disease, often leading to therapeutic failure. Moreover, recent increases in community-acquired C. difficile infections have led to greater numbers of investigations into the animal origin of the disease. The aim of this study was to evaluate the genetic similarities between 23 environmental and animal isolates by using whole-genome sequencing and to determine antimicrobial resistance and virulence factor genes in toxigenic C. difficile strains to provide important data for the development of diagnostic methods or treatment guidelines.
Results
The most common sequence type was ST11 (87%), followed by ST2 (9%) and ST19 (4%). In addition, 86.95% of the strains exhibited multidrug resistance, with antimicrobial resistance to mainly aminoglycosides, fluoroquinolones, tetracycline and B-lactams; nevertheless, one strain also carried other resistance genes that conferred resistance to lincosamide, macrolides, streptogramin a, streptogramin b, pleuromutilin, oxazolidinone and amphenicol. In addition, a wide range of virulence factor genes, such as those encoding adherence factors, exoenzymes and toxins, were found. However, we observed variations between toxinotypes, ribotypes and sequence types.
Conclusions
The results of this study demonstrated significant genetic similarity between ST11 strains isolated from environmental sampling and from animal origin; these strains may represent a reservoir for community-acquired C. difficile infection, which is becoming a growing public health threat due to the development of multridug resistant (MDR) bacteria and the number of virulence factors detected

Tercero-Guerrero D., Blanco JL., Hernandez M., Torre-Fuentes L., Alvarez J. and Garcia ME.

Whole-genome sequencing of toxigenic Clostridioides difcile reveals multidrug resistance and virulence genes in strains of environmental and animal origin

Whole-genome sequencing of toxigenic Clostridioides difcile reveals multidrug resistance and virulence genes in strains of environmental and animal origin

	Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM).
	Universidad de Valladolid (UVa).
	Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM).