Protectivity conferred by immunization with intranasal recombinant outer membrane protein H from <i>Pasteurella multocida</i> serovar A:1 in chickens

Abstract

Recombinant outer membrane protein H (rOmpH) is a potential fowl cholera vaccine candidate. The present study was aimed at developing rOmpH formulations for intranasal administration. The rOmpH was purified and formulated with either Escherichia coli enterotoxin B (LTB) or CpG oligodeoxynucleotides (ODN) as an adjuvant. Antibody responses in chickens intranasally immunized with rOmpH in combination with 2 different adjuvants were significantly increased (P<0.05) post immunization. Chicken survival rates showed that rOmpH formulated with ODN and LTB elicited 90% and 70% protection, respectively. Our findings indicated that rOmpH formulated with ODN elicited protection better than that formulated with LTB. Therefore, the vaccines formulations in the present study can be considered new intranasal vaccine formulations for fowl cholera in chickens.

Cross-protection conferred by immunization with an rOmpH-based intranasal fowl cholera vaccine

“…Bacterial strains, media and growth conditions P. multocida strains X-73 (serovar A:1, ATCC15742), P-1059 (serovar A:3, ATCC11039) and P-1662 (serovar A:4, provided by Prof. Dr Takuo Sawada, Nippon Veterinary and Life Science University, Tokyo, Japan) were grown in Tryptose broth (Difco Laboratories, Franklin Lakes, NJ, USA) at 37°C for 6 h and then subcultured on dextrose starch agar (Difco) at 37°C for 18 h. E. coli strain PQE-ompH (Thanasarasakulpong et al, 2015) was grown at 37°C in Luria-Bertani (LB) broth or on agar supplemented with 100 µg/ml ampicillin and 25 µg/ml kanamycin (Sigma-Aldrich, St. Louis, MO, USA).…”

“…The nasal vaccine is theoretically capable of enhancing the release of immunoglobulin A (IgA) at the mucosal surface, as well as serum immunoglobulin G or Y (IgG or IgY). In addition, the vaccination method can be conducted via nasal droplets or spraying (Woodrow et al, 2012); this is more convenient for use in a mass population or in farm bird flocks (Thanasarasakulpong et al, 2015). Induction of the immune response following mucosal vaccines usually depends upon the use of appropriate adjuvants that can initiate and support the transition from innate to adaptive immunity (Freytag & Clements, 2005).…”

“…It is a porin protein that is highly conserved among the Gram-negative bacteria (Luo et al, 1997). The OmpH of P. multocida strain X-73 plays an important role as a vaccine candidate for pasteurellosis (Luo et al, 1997;Sthitmatee et al, 2008;Thanasarasakulpong et al, 2015). Our previous studies demonstrated that the outer membrane protein H of P. multocida strain X-73 (serovar A:1) is a capsule-associated antigen and a cross-protective antigen among P. multocida capsular serogroup A strains (Ali et al, 2004a(Ali et al, , 2004bBorrathybay et al, 2003).…”

“…The recombinant outer membrane protein (rOmpH) of strain X-73 was prepared in Escherichia coli and purified by electroelution (Thanasarasakulpong et al, 2016). Purified rOmpH was formulated with the E. coli heat-labile enterotoxin B (LTB) and inoculated into laying hens via nasal administration (Thanasarasakulpong et al, 2015). Layers vaccinated with an intranasal rOmpH-based fowl cholera vaccine displayed sufficient protection against homologous avian P. multocida capsular type A strain, but the degree of protection conferred by this vaccine via the heterologous avian P. multocida capsular type A strains challenge exposure has yet to be quantified (Thanasarasakulpong et al, 2015).…”

“…Purified rOmpH was formulated with the E. coli heat-labile enterotoxin B (LTB) and inoculated into laying hens via nasal administration (Thanasarasakulpong et al, 2015). Layers vaccinated with an intranasal rOmpH-based fowl cholera vaccine displayed sufficient protection against homologous avian P. multocida capsular type A strain, but the degree of protection conferred by this vaccine via the heterologous avian P. multocida capsular type A strains challenge exposure has yet to be quantified (Thanasarasakulpong et al, 2015). Thus, the objectives of the present study were to determine the cross-protection conferred by immunization with an rOmpH-based intranasal fowl cholera vaccine and also to investigate the humoral or cellular immune responses post-vaccination.…”