Role of Clostridium perfringens Necrotic Enteritis B-like Toxin in Disease Pathogenesis

Abstract

Necrotic enteritis (NE) is a devastating enteric disease caused by Clostridium perfringens type A/G that impacts the global poultry industry by compromising the performance, health, and welfare of chickens. Coccidiosis is a major contributing factor to NE. Although NE pathogenesis was believed to be facilitated by α-toxin, a chromosome-encoded phospholipase C enzyme, recent studies have indicated that NE B-like (NetB) toxin, a plasmid-encoded pore-forming heptameric protein, is the primary virulence factor. Since the discovery of NetB toxin, the occurrence of NetB+ C. perfringens strains has been increasingly reported in NE-afflicted poultry flocks globally. It is generally accepted that NetB toxin is the primary virulent factor in NE pathogenesis although scientific evidence is emerging that suggests other toxins contribute to NE. Because of the complex nature of the host-pathogen interaction in NE pathogenesis, the interaction of NetB with other potential virulent factors of C. perfringens needs better characterization. This short review will summarize the primary virulence factors involved in NE pathogenesis with an emphasis on NetB toxin, and a new detection method for large-scale field screening of NetB toxin in biological samples from NE-afflicted commercial broiler flocks.

In Vivo Recovery of Bacteriophages and Their Effects on Clostridium perfringens-Infected Broiler Chickens

“…Necrotic enteritis (NE), an economically important enteric disease in the broiler industry, is caused by gram-positive anaerobic Clostridium perfringens type A/G that impacts the global industry by compromising the performance, health, and welfare of chickens [ 1 , 2 ]. C. perfringens toxinotypes are classified from A to G depending on their production capability for α-toxin, β-toxin, ε-toxin, ι-toxin, enterotoxin, and NE beta-like (NetB) toxin [ 2 ]. C. perfringens typically contains approximately 10 4 colony-forming units (cfu) per gram of digesta in the intestine of healthy birds [ 3 ].…”

“…Abbreviations: BW, body weight; BWG, body weight gain; FI, feed intake; FCR, feed conversion ratio 1. Values are least-squares means of 8 replicates unless otherwise stated 2. Values are least-squares means of 16 replicates 3.…”

“…Vitamin mixture provided the following nutrients per kilogram of diet: vitamin A, 9000 IU; vitamin D3, 4000 IU; vitamin E, 58 mg; vitamin K3, 2.7 mg; vitamin B1, 2.3 mg; vitamin B2, 5.9 mg; vitamin B5, 17 mg; vitamin B6, 2.9 mg; vitamin B12, 0.015 mg; Niacin, 54 mg; Folic, 1.7 mg; biotin, 0.16 mg 2. Mineral mixture provided the following nutrients per kilogram of diet: Mn, 85.7 mg; Cu, 100 mg; Zn, 64.3 mg; Fe, 57.1 mg; I, 0.57 mg; Co, 0.17 mg; Se, 0.2 mg.…”

Bioactive compounds, antibiotics and heavy metals: Effects on the intestinal structure and microbiome of monogastric animals – a non-systematic review

“…Disturbances in the composition of the gut microbiota can be a reason for the malformation of guts, which has a critical impact on the animal health. An excessive population size of Clostridium perfringens of A/G type in the small intestine causes necrotic enteritis in poultry aged 2-6 weeks (Lee and Lillehoj, 2022). Toxins produced by these bacteria damage the intestinal wall; in a sub-clinical form they lead to decreased feed intake and digestive disorder, and in a clinical form they cause up to 50% of birds' mortality in 24 hours (Uzal et al, 2014;Caly et al, 2015;Tsiouris, 2016;Broom, 2017).…”

“…Toxins produced by these bacteria damage the intestinal wall; in a sub-clinical form they lead to decreased feed intake and digestive disorder, and in a clinical form they cause up to 50% of birds' mortality in 24 hours (Uzal et al, 2014;Caly et al, 2015;Tsiouris, 2016;Broom, 2017). It is assumed that the main virulent factor is NetB toxin, heptameric protein encoded by plasmid, although some scientific evidence implies that other toxins take part in the pathogenesis of necrotic enteritis (Lee and Lillehoj, 2022). Ulcerative colitis is a disease caused by Clostridium colinum, with a mortality rate reaching up to 100% in several days' (Radi, 2004).…”