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BioMed Research International
Volume 2016, Article ID 1512690, 12 pages
Research Article

Enteric Pathogens and Coinfections in Foals with and without Diarrhea

1Department of Veterinary Clinical Sciences, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
2Department of Veterinary Hygiene and Public Health, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
3Department of Preventive Veterinary Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
4Department of Genetics, Evolution and Bioagents, Campinas State University (Unicamp), Campinas, SP, Brazil
5Department of Preventive Veterinary Medicine, University of São Paulo, São Paulo, SP, Brazil
6Department of Animal Hygiene, Kitasato University, Towada, Aomori, Japan

Received 15 September 2016; Accepted 23 November 2016

Academic Editor: Eric N. Villegas

Copyright © 2016 Giovane Olivo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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) () and nondiarrheic (ND) foals () up to three months of age were studied. Fecal samples were analyzed for identification of infectious agents (microbiological culturing, molecular techniques, and microscopic analyses). Escherichia coli fimH (30% versus 25%), Salmonella spp. (25% versus 7%), Strongyloides westeri (25% versus 25%), Clostridium perfringens type A (21% versus 10%), E. coli ag43 (20% versus 35%), Strongylus (11% versus 18%), and vapA-positive Rhodococcus equi (5% versus 2%) were the most frequent enteric pathogens detected in D and ND foals, respectively. The frequency of toxin A-positive C. perfringens was significantly increased in the D () compared with the ND animals. R. equi 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.