Differential expression of intestinal genes in necrotic enteritis challenged broiler chickens with 2 different Clostridium perfringens strains

Abstract

<p>The primary cause of necrotic enteritis (<b>NE</b>) disease in chickens is the NetB-positive <I>Clostridium perfringens</I> bacterium. Many factors are known to affect the severity of NE in the challenge models of broiler chickens, and one of these factors is the virulence of <I>C. perfringens</I> strain. This study was conducted to evaluate the effect of 2 pathogenic <I>C. perfringens</I> strains in a NE challenge model on gut health and mRNA expression of genes encoding apoptosis, tight junction, immunity, and nutrient transporters in broilers. Day-old Ross-308 male broilers (<I>n</I> = 468) were allocated in a 2 × 3 factorial arrangement of treatments with in-feed antibiotics (no or yes) and challenge (Non, <I>C. perfringens</I> strain NE18, and <I>C. perfringens</I> strain NE36) as the factors. The birds in the challenged groups were inoculated with <I>Eimeria</I> species on day 9 and with a fresh suspension of <I>C. perfringens</I> NE18 or NE36 on day 14 and 15. Sample collection was performed on 2 birds of each pen on day 16. Necrotic enteritis challenge, impaired feed conversion ratio during day 0 to 16 compared with the control group where the effect of the NE36 challenge was more severe than that with NE18 (<I>P</I> < 0.001). The mRNA expression of mucin-2, immunoglobulin-G, occludin (<I>P</I> < 0.001), and tight junction protein-1 (<I>P</I> < 0.05) genes were downregulated in both challenged groups compared with the nonchallenged counterparts. Antibiotic supplementation, on the other hand, increased weight gain, and feed intake in all challenged birds (<I>P</I> < 0.01), but upregulated mucin-5ac and alanine, serine, cysteine, and threonine transporter-1 (<I>P</I> < 0.05) only in the NE18 challenged birds. The challenge with NE36 significantly upregulated caspase-8 and claudin-1 (<I>P</I> < 0.001), but downregulated glucose transporter-2 (<I>P</I> < 0.001) compared with the NE18 challenge. These results suggest that NE challenge is detrimental to the performance of broilers through compromised intestinal health, and different <I>C. perfringens</I> strains can affect the severity of the disease through modulating the expression of intestinal genes encoding proteins responsible for apoptosis, gut integrity, immunity, mucus production, and nutrient transporters.</p>