Clostridioides (Clostridium) difficile-associated diarrhea in equine in Minas Gerais, Brazil: clinical and microbiological characterization of six cases

ABSTRACT: Clostridioides (Clostridium) difficile is the main causative agent of antimicrobial-related diarrhea in humans and a major pathogen-associated enteric disorder in foals and adult horses. Moreover, studies have suggested that animals are a possible reservoir of toxigenic C. difficile strains for humans. Despite this known importance, the epidemiology of C. difficile infection (CDI) in equine is still largely unknown. Therefore, this study described six cases of equine CDI occurring in Minas Gerais, Brazil, including the characterization of the isolates. All but one equine included in this research developed CDI after antimicrobial therapy, three of which occurred during hospitalization. Coinfection with Salmonella Heidelberg and S. Infantis was detected in three cases, making the antimicrobial treatment challenging. All animals recovered after metronidazole administration. All C. difficile isolates were susceptible to metronidazole and vancomycin, while three were resistant to moxifloxacin and two were resistant to clindamycin. The isolates were classified as RT126 (n = 4), RT078 (n = 1), and RT014/020 (n = 1), all previously reported infecting humans and animals worldwide.