Clostridium perfringens strains from bovine enterotoxemia cases are not superior in in vitroproduction of alpha toxin, perfringolysin O and proteolytic enzymes

Evy Goossens,Stefanie Verherstraeten,Freddy Haesebrouck,Leen Timbermont,Filip Van Immerseel,Piet R Deprez,Richard Ducatelle,Bart Pardon,Bonnie R Valgaeren

doi:10.1186/1746-6148-10-32

Abstract

BackgroundBovine enterotoxemia is a major cause of mortality in veal calves. Predominantly veal calves of beef cattle breeds are affected and losses due to enterotoxemia may account for up to 20% of total mortality. Clostridium perfringens type A is considered to be the causative agent. Recently, alpha toxin and perfringolysin O have been proposed to play an essential role in the development of disease. However, other potential virulence factors also may play a role in the pathogenesis of bovine enterotoxemia. The aim of this study was to evaluate whether strains originating from bovine enterotoxemia cases were superior in in vitro production of virulence factors (alpha toxin, perfringolysin O, mucinase, collagenase) that are potentially involved in enterotoxemia. To approach this, a collection of strains originating from enterotoxemia cases was compared to bovine strains isolated from healthy animals and to strains isolated from other animal species.ResultsStrains originating from bovine enterotoxemia cases produced variable levels of alpha toxin and perfringolysin O that were not significantly different from levels produced by strains isolated from healthy calves and other animal species. All tested strains exhibited similar mucinolytic activity independent of the isolation source. A high variability in collagenase activity between strains could be observed, and no higher collagenase levels were produced in vitro by strains isolated from enterotoxemia cases.ConclusionsBovine enterotoxemia strains do not produce higher levels of alpha toxin, perfringolysin O, mucinase and collagenase, as compared to strains derived from healthy calves and other animal species in vitro.

Highlights

Bovine enterotoxemia is a major cause of mortality in veal calves
Clostridium perfringens strains from enterotoxemia cases are not superior alpha toxin and perfringolysin O producers To determine whether alpha toxin and perfringolysin O levels differ between bovine enterotoxemia strains and strains from other sources, the culture supernatants of various type A strains were tested (Figure 1A)
The alpha toxin activity was below the detection limit of 15.6 10-3 U/ml

Summary

Introduction

Bovine enterotoxemia is a major cause of mortality in veal calves. Predominantly veal calves of beef cattle breeds are affected and losses due to enterotoxemia may account for up to 20% of total mortality. Clostridium perfringens is an anaerobic grampositive spore-forming bacterium, which is a commensal traits can be proteolytic factors that degrade the protective mucus layer and extracellular matrix components or intraspecies inhibitory antibacterial substances that confer a selective advantage to the producing strain, as suggested for necrotic enteritis strains in broilers [9]. It is hitherto unclear whether the C. perfringens type A strains isolated from enterotoxemia cases are more virulent than other type A strains. In a calf intestinal loop model, it has been shown that C. perfringens strains isolated from healthy and enterotoxemic cattle as well as from other host species are all capable of inducing necrohemorrhagic intestinal lesions [10]

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