Molecular detection and characterization of cpb2 gene in Clostridium perfringens isolates from healthy and diseased chickens

A Tolooe,B Shojadoost,Sm Peighambari

doi:10.1590/s1678-91992011000100008

A Tolooe, B Shojadoost + Show 1 more

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https://doi.org/10.1590/s1678-91992011000100008

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Abstract

Clostridium perfringens is an important pathogen in both human and veterinary medicine. Necrotic enteritis (NE) is the most clinically dramatic bacterial enteric disease of poultry induced by C. perfringens. The pathogenicity of this bacterium is associated with the production of extracellular toxins produced by some of its strains, such as beta2 toxin. The exact role of beta2 toxin in NE pathogenesis is still controversial. In the present study, C. perfringens isolates from healthy and diseased poultry flocks from different parts of Iran were analyzed by PCR assay to determine the presence of all variants of the beta2 toxin gene (cpb2). The products of two positive cpb2 PCR reactions were sequenced, compared to each other and to the cpb2 sequences published in GenBank (by multiple alignment and phylogenetic analysis). The current work represents the first study of cpb2 in poultry C. perfringens isolates in Asia, and reports the highest percentage of cpb2-positive isolates in both apparently healthy chickens (97.7%) and those afflicted with NE (94.4 %). The sequenced isolates were classified as atypical. This study did not show a direct correlation between NE occurrence and cpb2 presence.

Highlights

Clostridium perfringens, an anaerobic grampositive bacterium, is an important pathogen among humans and many other animal species [1]
Out of 36 isolates obtained from diseased flocks, 34 were positive (94.4%) for the cpb2 gene
Sequence and Phylogenetic Analysis Comparison of two Iranian C. perfringens isolates, ATBS61tIR and ATBS100tIR, sequenced by Blast-N at the nucleotide level revealed 99% similarity to each other and 73 to 100% identity with the cpb2 sequences of C. perfringens strains available in GenBank

Summary

Introduction

Clostridium perfringens, an anaerobic grampositive bacterium, is an important pathogen among humans and many other animal species [1]. In poultry, it can cause a deadly disease called necrotic enteritis (NE). In addition to the so-called major toxins, there are at least 13 minor toxins or enzymes produced by some strains of C. perfringens, which may play a role in pathogenicity. These compounds include beta, netB, delta, theta, kappa, lambda, mu, nu, gamma, eta, neuraminidase, urease and enterotoxin [1, 3]. While the roles of beta, iota, and epsilon toxins in enteritis pathogenesis among animals are well documented, the roles of other toxins, such as alpha, netB, and beta toxin, in NE pathogenesis are still unclear [3,4,5,6,7]

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