Isolation of Clostridioides difficile in foals and mares

• Grant number: 24/01073-6
• Support Opportunities: Scholarships in Brazil - Master
• Start date: December 01, 2024
• End date: February 28, 2026
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
• Principal Investigator: Alexandre Secorun Borges
• Grantee: Landa Munhoz Dornelles
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Clostridioides difficile is an anaerobic, gram-positive bacterium, part of the intestinal microbiota of animals and humans. It has the ability to form spores, a characteristic that provides resistance to adverse environments. Its vegetative form can produce toxins (TcdA, TcdB, and CDT) responsible for gastrointestinal tract disturbances. In horses, the agent has been isolated from foals and adult horses, both healthy and sick. In the environment, amidst organic matter, it can survive for up to four years. The project's objective is to evaluate the occurrence of C. difficile in foals, mares, and the environment in stud farms and to relate this to the transfer of passive immunity in foals. Fecal samples will be collected from foals between 24 and 48 hours of life (n=50), mares (n=50), swabs from the mares' udders (n=50), and soil samples (n=20). The project will be carried out in different stud farms, with and without a prior history of diarrhea cases in foals caused by C. difficile. The samples will be inoculated in non-selective enrichment broth supplemented with 0.1% sodium taurocholate and incubated at 37°C for seven days. Subsequently, inoculation will be performed on CDMN agar; samples with morphology suggestive of C. difficile will be subcultured for DNA extraction. Multiplex PCR will be performed to identify toxin-producing genes (tcdA, tcdB, cdtA, and cdtB) and ribotyping by capillary electrophoresis. Statistical analysis will be carried out using the chi-square test or Fisher's exact test, with a P value <0.05.