Mucosal and systemic lymphoid immune responses against Clostridium perfringens strains with variable virulence in the production of necrotic enteritis in broiler chickens

Intracloacal Inoculation of Broiler Chickens with Clostridium perfringens Strains: Evaluation of Necrotic Enteritis Disease Development and Lymphoid Immune Responses

“…Isolates were grown and stored in cooked meat medium (CMM) (Oxoid, KS, USA). While the CP5 was found to be avirulent in our previous oral infection challenge experiments in broiler chickens [ 4 , 19 ], the CP18 and CP26 that carried an additional tpeL gene were found to be virulent [ 4 ].…”

“…Three experimental groups were infected with C. perfringens strains, CP5, CP18, or CP26, and the infected chickens were kept in rooms separate from the uninfected (negative control) group of birds. For infection, C. perfringens strains were grown anaerobically in cooked meat medium (CMM) for 24 h at 37 °C, as described previously [ 4 ]. The fluid thioglycolate medium (FTG, Difco, Franklin Lakes, NJ, USA) was then inoculated with a 3% ( v/v ) inoculum from the C. perfringens -infected CMM and incubated at 37 °C for 15 h. Chickens were challenged intracloacally, when they were 18 days old, with 1mL of culture containing about 5.8–8 × 10 8 CFU of C. perfringens twice daily for 4 consecutive days.…”

“…Necrotic enteritis (NE), caused by the NetB toxin-producing virulent strains of Clostridium perfringens type G, is a multifactorial disease of chickens [ 1 ]. In recent years, another toxin, TpeL, has also been shown to enhance the virulence in some netB + C. perfringens [ 2 , 3 , 4 ]. The disease occurs in two forms: clinical and subclinical.…”

“…More recently, we used an experimental oral inoculation model of broiler chickens comprised of only dietary predisposition to test the virulence of different C. perfringens strains, as well as the strain-specific host immune responses [ 4 ]. The study used three netB + C. perfringens , namely CP5 ( tpeL - ), CP18 ( tpeL + ), and CP26 ( tpeL + ), to find CP5 as avirulent, while CP18 and CP26 were virulent, producing ulcerative and necrotic lesions characteristic of clinical NE.…”

“…In another study, we also found that macrophages may be the cellular source of inflammatory cytokines induced in response to virulent C. perfringens [ 18 ]. In the present study, we asked if intracloacal inoculation of broiler chickens with the same C. perfringens strains (CP5, CP18, and CP26) and the dietary predisposition model used previously [ 4 ] would impact the severity of NE development and its associated mucosal and systemic lymphoid immune responses. To address this question, first, a previously established NE lesion scoring system [ 12 ], along with the body weight gain data, was used to assess the nature (clinical or subclinical) of NE.…”