Molecular characterization of virulence genes cctA, nanA, and fliC in Clostridium chauvoei from Rio Grande do Sul and São Paulo State, Brazil

Gregório Miguel Ferreira De Camargo,Joachim Frey,Rosangela Estel Ziech,Agueda Castagna De Vargas,Daniel Mendes Pereira Ardisson-Araújo,Luana D’Avila Farias

doi:10.1590/0103-8478cr20181006

Abstract

ABSTRACT: Clostridium chauvoei toxin A (CctA), neuraminidase (NanA), and flagellin (FliC) proteins contribute to the pathogenicity of Clostridium chauvoei, the causative agent of blackleg in cattle. The aim of this study was to analyze the genetic variability of cctA, nanA, and fliC genes in C. chauvoei isolates from the Rio Grande do Sul and São Paulo state- Brazil, during different sampling periods. The presence of these genes was verified through PCR amplification and partial gene sequencing of 17 strains. Alignment of PCR amplicons combined with bioinformatics analysis was used in an attempt to study the variability across C. chauvoei solates. The similarity among the partial sequences of cctA and nanA genes was 100%. The sequencing of fliC revealed three different paralog alleles of flagellin, and two strains were seen to be polymorphic, with amino acid alterations in the predicted protein. Overall, this study indicates that strains of C. chauvoei isolated in Brazil are highly conserved with respect to the virulence factors evaluated.

Highlights

Blackleg is a universal disease of cattle
Clostridium chauvoei toxin A (CctA), neuraminidase (NanA), and flagellin (FliC) proteins contribute to the pathogenicity of Clostridium chauvoei, the causative agent of blackleg in cattle
This study indicates that strains of C. chauvoei isolated in Brazil are highly conserved with respect to the virulence factors evaluated

Summary

Introduction

Blackleg is a universal disease of cattle. It is an acute, endogenous/soil-borne infection caused by Clostridium chauvoei, a Gram positive, motile, histotoxic, and sporulating anaerobic bacterial species (USEH et al, 2006a). Current knowledge indicates that the toxins, DNAse, hyaluronidase, hemolysin, sialidase, and flagellar protein seem to play an important role in pathogenicity of C. chauvoei (FREY & FALQUET, 2014). The only well characterized virulence factors of C. chauvoei are sialidase (HEUERMANN et al, 1991; USEH et al, 2006b; USEH et al, 2003; VILEI et al, 2011), Clostridium chauvoei toxin A (CctA) (FREY et al, 2012), and flagellin (KOJIMA et al, 2000; TAMURA et al, 1995; TANAKA et al, 1987). The β-barrel protein porin, leukocidine CctA, has been shown to constitute the main virulence factor of C. chauvoei.

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Conclusion