Enteric Pathogens and Coinfections in Foals with and without Diarrhea.

Abstract

Diarrhea is a major clinical problem affecting foals up to 3 months of age. The aim of this study was to identify enteric microorganisms involved in monoinfections and coinfections and the associated virulence factors in healthy and diarrheic foals. Diarrheic (D) (= 56) and nondiarrheic (ND) foals (= 60) up to three months of age were studied. Fecal samples were analyzed for identification of infectious agents (microbiological culturing, molecular techniques, and microscopic analyses).(30% versus 25%),spp. (25% versus 7%),(25% versus 25%),type A (21% versus 10%),(20% versus 35%),(11% versus 18%), and-positive(5% versus 2%) were the most frequent enteric pathogens detected in D and ND foals, respectively. The frequency of toxin A-positivewas significantly increased in the D (= 0.033) compared with the ND animals.strains harboring virulent plasmids were also identified (VapA 85-kb type I and VapA 87-kb type I) in D and ND foals. Coinfections were observed in 46% of the D and 33% of the ND foals. Our results demonstrate the great diversity of enteric pathogens, virulence factors, and coinfections involved in enteric infections of foals.