Bacillus subtilis PB6 improves intestinal health of broiler chickens challenged with Clostridium perfringens-induced necrotic enteritis

Abstract

Necrotic enteritis (NE) is an enterotoxemic disease caused by Clostridium perfringens that results in significant economic losses, averaging damage of $0.05 per bird. The present study investigated the influence of a dietary supplement, Bacillus subtilis PB6, on performance, intestinal health, and gut integrity against C. perfringens-induced NE in broiler birds. Bacillus subtilis PB6 (ATCC-PTA 6737) is a natural strain isolated from healthy chicken gut that has been shown in in vitro to produce antimicrobial substances with broad activity against various strains of Campylobacter and Clostridium species. The animal study was conducted on broiler chickens (Cobb 400) for the period of 35 d using a completely randomized design. The experimental design included 3 treatments groups. Each treatment group contained 6 replicates, 3 male and 3 female, with 12 birds in each replicate. The 3 treatment groups were an uninfected control, an infected control, and an infected group supplemented with B. subtilis PB6 at 500 g/t of feed, containing 5 × 10(11) cfu/kg. Necrotic enteritis was induced in the broiler birds via oral inoculation of 30,000 oocysts of mixed strains of Eimeria species on d 14 followed by C. perfringens (10(8) cfu/mL) on d 19 through 21 of trial. The birds were analyzed for BW gain, mortality, feed conversion ratio (FCR), intestinal lesion score, intestinal C. perfringens counts, and villus histomorphometry. The infected control group showed markedly thickened mucosa, hemorrhages, intestinal lesions, and ballooning of intestine. The supplementation of B. subtilis PB6 reduced the FCR (P < 0.05) and intestinal C. perfringens counts significantly (P < 0.05) compared with the infected control group. It was also observed that B. subtilis PB6 improved villi length by 10.88 and 30.46% (P < 0.05) compared with uninfected and infected control groups, respectively. The group supplemented with B. subtilis PB6 significantly (P < 0.05) increased the villi length to crypt depth ratio by 49.11% compared with the infected group. In conclusion, the supplementation of B. subtilis PB6 not only controlled C. perfringens-induced NE, but also improved intestinal health in the broiler birds.

Effects of dietary inclusion of probiotics, prebiotics and synbiotics on intestinal histological changes in challenged broiler chickens

“…In addition, the broad tips of the intestinal villi with the proliferation of enterocytes, together with heterophil infiltration and oedema in the lamina propria, were consistent with the results by Olkowski et al (2006). The results of this study are consistent with those of Jayaraman et al (2013), who reported that birds infected with C. perfringens showed markedly thickened mucosa, haemorrhages and intestinal ballooning. Asaoka et al (2004), Yang et al (2009) and Khambualai et al (2010) found that NE was characterized by extensive necrosis in the mucosa and haemorrhages, as well as inflammatory cell infiltration in birds infected with C. perfringens.…”

“…Abdel-Raheem et al (2012) and Sen et al (2012) reported that dietary supplementations of B. subtilis increased villus length in comparison with the dietary control. In a later study, B. subtilis was found to increase the length and surface area of villi when compared with the positive control group under challenge by C. perfringens (Jayaraman et al, 2013). Higher surface area in villi was reported as a result of MOS supplementation as prebiotic compared with the control group (Loddi et al, 2002).…”

“…Studies showed that the Bacillus subtilis strain improved intestinal microflora and inhibited pathogenic strains such as campylobacter and Clostridium species in broiler chickens (Mountzouris et al, 2007;Nayebpor et al, 2007;Ashayerizadeh et al, 2011;Abudabos et al, 2013). On the other hand, B. subtilis was shown to have a positive effect on the histomorphological and gut integrity of villi against C. perfringens-induced NE in broiler birds (Jayaraman et al, 2013).…”

Efficacy of Bacillus Subtilis (GalliPro) supplementation in Clostridium perfringens challenged necrotic enteritis of broiler chicken

“…The presence of higher mean Clostridium perfringens count in the birds exposed for necrotic enteritis challenge devoid of supplementation of B. subtilis (T3) as compared to any of the other treatment groups or healthy control birds and decrease in mean concentration of Clostridium perfringens count in healthy supplemented with B. subtilis group is comparable with results of Jayaraman et al (2013) where they reported significantly lower count of Clostridium perfringens; Maruta et al (1996) also observed protection of birds against Clostridium perfringens using B. subtilis C-3102 in the feed . The intestinal microbial analysis for Clostridium perfringens count concluded that supplementation of Bacillus subtilis reduces the damage caused in necrotic enteritis infection in broiler birds as well as under disease free condition supplementation of B. subtilis helps in improving gut health and overall growth performance of birds.…”

“…presence of higher villi length in necrotic enteritis challenged birds supplemented with B. subtiis and in non-infected group supplemented with B. subtils are in consistency with Samanaya and Yamuchi (2002) as they have also reported improved histologies in probiotic supplemented birds in terms of villus length. It was also reported by Jayaraman et al (2013) that B. subtilis supplemented birds showed better villi health in comparison to any other groups which indicated that it could be possible that Bacillus subtilis acts independent of the infection in improving the gut health.…”