Two Lactobacillus Species Inhibit the Growth and α-Toxin Production of Clostridium perfringens and Induced Proinflammatory Factors in Chicken Intestinal Epithelial Cells in Vitro.

Shuangshuang Guo,Zhui Li,Yuming Guo,Binying Ding,Dan Liu,Yehan Li,Beibei Zhang

doi:10.3389/fmicb.2017.02081

Abstract

Clostridium perfringens is the causative pathogen of avian necrotic enteritis. Lactobacillus spp. are well-characterized probiotics with anti-microbial and immune-modulatory activities. In the present study, we investigated the effects of L. acidophilus and L. fermentum on the growth, α-toxin production and inflammatory responses of C. perfringens. In in vitro culture experiments, both lactobacilli inhibited the growth of C. perfringens (P < 0.01), accompanied with a decrease in pH (P < 0.01). Supernatants from lactobacilli cultures also suppressed the growth of C. perfringens during 24 h of incubation (P < 0.01), but this inhibitory effect disappeared after 48 h. Both lactobacilli decreased the α-toxin production of C. perfringens (P < 0.01) without influencing its biomass, and even degraded the established α-toxin (P < 0.01). Lower environmental pH reduced the α-toxin production as well (P < 0.01). Preincubation with L. acidophilus decreased the attachment of C. perfringens to cells (P < 0.01) with the cell cytotoxicity being unaffected. Both lactobacilli pretreatment reduced the up-regulation of proinflammatory factors, peptidoglycan (PGN) receptors and nuclear factor kappa B (NF-κB) p65 in C. perfringens-challenged chicken intestinal epithelial cells (P < 0.05). In conclusion, L. acidophilus and L. fermentum inhibited the pathological effects of C. perfringens in vitro conditions.

Highlights

Clostridium perfringens is a robust Gram-positive anaerobic spore-forming and rod-shaped bacterium, and able to produce up to 18 toxins and extracellular enzymes, causing diseases, such as necrotic enteritis (NE) in poultry, equine colitis, food poisoning, and gas gangrene (Songer and Meer, 1996; Revitt-Mills et al, 2015)
It was reported that α-toxin was detected in the intestines of broiler chickens inoculated with a α-toxin mutant strain of C. perfringens and there was a direct relationship between intestinal lesion severity and amount of αtoxin determined in the gut contents and mucosa (R = 0.89–0.99) (Coursodon et al, 2010)
The purpose of this study was to investigate the effects of Lactobacillus acidophilus and Lactobacillus fermentum on the growth and αtoxin production of C. perfingens as well as the inflammatory responses induced by this pathogen in the intestinal epithelial cells of chicken embryos

Summary

Introduction

Clostridium perfringens is a robust Gram-positive anaerobic spore-forming and rod-shaped bacterium, and able to produce up to 18 toxins and extracellular enzymes, causing diseases, such as necrotic enteritis (NE) in poultry, equine colitis, food poisoning, and gas gangrene (Songer and Meer, 1996; Revitt-Mills et al, 2015). Α-toxin is a key mediator of human gas gangrene and bovine necro-haemorrhagic enteritis (Bryant et al, 2000; Goossens et al, 2017). It could result in myonecrosis, hemorrhage and neutrophil infiltration in human and animals

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