Virulence factors and phylotyping of Escherichia coli isolated from non-diarrheic and diarrheic water buffalo calves/Caracterizacao dos fatores de virulencia e filogrupos de Escherichia coli isoladas de bezerros bubalinos sem diarreia e diarreicos

• Published in: Ciência rural Vol. 49; no. 5
• Main Authors: Coura, Fernanda Morcatti, de Araujo Diniz, Soraia, Silva, Marcos Xavier, de Oliveira, Cairo Henrique Sousa, Mussi, Jamili Maria Suhet, de Oliveira, Camila Stefanie Fonseca, Lage, Andrey Pereira, Heinemann, Marcos Bryan
• Format: Journal Article
• Language: English
• Published: Universidade Federal de Santa Maria 01.05.2019
• Subjects: Brasil
• ISSN: 0103-8478; 1678-4596
• DOI: 10.1590/0103-8478cr20180998

This study aimed to determine the virulence factors, phylogenetic groups, and the relationships between pathovars and phylogenetic groups of E. coli strains isolated from feces of buffalo calves. A total of 217 E. coli strains were obtained from feces after culture and were screened by PCR for detection of virulence factors EAST-1, enterohemolysin, Saa, CNF2, F41, F5, STa, intimin, Stx1 and Stx2. One hundred and thirty-four isolates were positive for one or more virulence factors: eighty-four from diarrheic animals, and fifty from non-diarrheic calves. The pathovars of E. coli identified in diarrheic feces were ETEC ([F5.sup.+]) (2/84), NTEC (16/84), STEC (20/84), EPEC (3/84), EHEC (3/84), and EAEC ([EAST-1.sup.+]) (33/84). Pathovars identified in non-diarrheic animals were NTEC (21/50), STEC (17/50), EHEC (1/50) and EAEC (7/50). E. coli strains positive for EAST-1 (P=0.008) and phylogroup C (P = 0.05) were associated with the presence of diarrhea. Phylogenetic analysis showed that 58.95% of the isolates belonged to phylogroup B1, followed by E (9.70%), B2 (5.90%), C (5.90%), D (5.22%), A (2.24%), and F (1.50%). Phylogroup B1 predominated in pathogenic E. coli isolated from water buffalo, and phylogroup C constituted an enteropathogenic E. coli for water buffalo calves. Key words: buffalo calves, diarrhea, Escherichia coli, pathovars, phylogenetic group. O objetivo foi determinar os fatores de virulencia, os grupos filogeneticos e as possiveis relacoes entre os patovares e os grupos filogeneticos identificados de cepas de Escherichia coli isoladas de fezes de bezerros bubalinos. Um total de 217 amostras de E. coli foram identificadas a partir de cultura das fezes e submetidas a reacao em cadeia da polimerase (PCR) para deteccao dos fatores de virulencia EAST-1, enterohemolisina, Saa, CNF2, F41, F5, STa, intimina, Stx1 e Stx2. Foram identificadas 134 cepas positivas para um ou mais fatores de virulencia: 84isoladas de bezerros bubalinos diarreicos e 50 de bezerros bubalinos saudaveis. Os patovares de E. coli obtidos de fezes diarreicas foram ETEC ([F5.sup.+]) (2/84), NTEC (16/84), STEC (20/84), EPEC (3/84), EHEC (3/84), e EAEC ([EAST-1.sup.+]) (33/84). Os patovares isolados de fezes nao diarreicas foram NTEC (21/50), STEC (17/50), EHEC (1/50) e EAEC (7/50). Cepas de E. coli positivas para EAST-1 (P = 0,008) e filogrupo C (P = 0,05) foram associadas com a presenca de diarreia. A analise de filogrupos revelou que 58,95% dos isolados pertencem ao filogrupo B1, seguido por E (9,70%), B2 (5,90%), C (5,90%), D (5,22%), A (2,24%) e F (1,50%). O filogrupo B1 predomina em cepas de E. coli patogenicas isoladas de bezerros bufalos e o filogrupo C constitui um filogrupo de E. coli patogenica enterica para bezerros. Palavras-chave: bezerros bubalinos; dirreia, Escherichia coli;,grupo filogenetico, patovares.