| Autor: |
De Lorenzo C; Department of Veterinary Pathology, School of Veterinary Medicine, Federal University of Rio Grande do Sul, Porto Alegre 91540-000, Brazil.; State Foundation of Livestock Research, Eldorado do Sul 92990-000, Brazil., de Andrade CP; Department of Veterinary Pathology, School of Veterinary Medicine, Federal University of Rio Grande do Sul, Porto Alegre 91540-000, Brazil., Machado VSL; Department of Veterinary Pathology, School of Veterinary Medicine, Federal University of Rio Grande do Sul, Porto Alegre 91540-000, Brazil., Bianchi MV; Department of Veterinary Pathology, School of Veterinary Medicine, Federal University of Rio Grande do Sul, Porto Alegre 91540-000, Brazil., Rolim VM; Department of Veterinary Pathology, School of Veterinary Medicine, Federal University of Rio Grande do Sul, Porto Alegre 91540-000, Brazil., Cruz RAS; Department of Veterinary Pathology, School of Veterinary Medicine, Federal University of Rio Grande do Sul, Porto Alegre 91540-000, Brazil., Driemeier D; Department of Veterinary Pathology, School of Veterinary Medicine, Federal University of Rio Grande do Sul, Porto Alegre 91540-000, Brazil.; State Foundation of Livestock Research, Eldorado do Sul 92990-000, Brazil. |
| Abstrakt: |
Enterotoxigenic Escherichia coli (ETEC) causes diarrhea in pigs, referred to as colibacillosis. The aim of this study was to optimize multiplex polymerase chain reaction (PCR) and immunohistochemistry (IHC) analyses of paraffin-embedded material to detect pathogenic E. coli strains causing colibacillosis in pigs. Multiplex PCR was optimized for fimbriae (F18, F4, F6, F5, and F41) and toxins (types A and B heat-stable toxins [STaP and STb], heat-labile toxin [LT], and type 2 Shiga toxin [STx 2e ]), and IHC was optimized for an anti- E. coli polyclonal antibody. Samples (132) from pigs received between 2006 and 2014 with clinical and histopathological diagnoses of colibacillosis were analyzed. E. coli was detected by IHC in 78.7%, and at least one virulence factor gene was detected in 71.2%. Pathogenic strains of ETEC with at least one fimbria and one toxin were detected in 40% of the samples in multiplex PCR. The most frequent virulence types were F18-STaP (7.5%), F18-STaP-STb (5.7%), and F4-STaP (3.8%). A statistically significant association was noted between virulence factors F4, F18, STaP, and STb and positive immunostaining results. Colibacillosis diagnosis through multiplex PCR and IHC of paraffin-embedded tissues is a practical approach, as samples can be fixed and stored for long periods before analysis. |
