Year-end Sale % OFF 
Abstract
BackgroundPasteurella multocida (P. multocida) is an important veterinary pathogen that can cause severe diseases in a wide range of mammals and birds. The global regulator crp gene has been found to regulate the virulence of some bacteria, and crp mutants have been demonstrated to be effective attenuated vaccines against Salmonella enterica and Yersinia enterocolitica. Here, we first characterized the crp gene in P. multocida, and we report the effects of a crp deletion.ResultsThe P. multocida crp mutant exhibited a similar lipopolysaccharide and outer membrane protein profile but displayed defective growth and serum complement resistance in vitro compared with the parent strain. Furthermore, crp deletion decreased virulence but did not result in full attenuation. The 50 % lethal dose (LD50) of the Δcrp mutant was 85-fold higher than that of the parent strain for intranasal infection. Transcriptome sequencing analysis showed that 92 genes were up-regulated and 94 genes were down-regulated in the absence of the crp gene. Finally, we found that intranasal immunization with the Δcrp mutant triggered both systematic and mucosal antibody responses and conferred 60 % protection against virulent P. multocida challenge in ducks.ConclusionThe deletion of the crp gene has an inhibitory effect on bacterial growth and bacterial resistance to serum complement in vitro. The P. multocida crp mutant was attenuated and conferred moderate protection in ducks. This work affords a platform for analyzing the function of crp and aiding the formulation of a novel vaccine against P. multocida.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-016-0739-y) contains supplementary material, which is available to authorized users.
Highlights
Pasteurella multocida (P. multocida) is an important veterinary pathogen that can cause severe diseases in a wide range of mammals and birds
Crp has been shown to control the expression of essential virulence factors, and crp mutants attenuate the virulence of many Gram-negative bacteria, including Salmonella enterica [23], Mycobacterium tuberculosis [24], Vibrio cholerae [25] and pathogenic Yersinia species [26, 27]
Cloning and characterization of the crp gene of P. multocida The coding region of the suspected crp gene (PM1157) in P. multocida strain 0818 was cloned via PCR, sequenced and deposited in GenBank
Summary
Pasteurella multocida (P. multocida) is an important veterinary pathogen that can cause severe diseases in a wide range of mammals and birds. Global regulators play a vital role in the adaption of bacteria to the environmental changes that are encountered during infection, such as the PhoP/PhoQ regulators, which induce modifications of lipopolysaccharides (LPS) or outer membrane proteins (OMPs) to deal with environmental extremes and promote bacterial survival [5]. Many of these regulators are closely related to virulence [6,7,8,9,10,11] and are proven mutation targets for vaccine development [12, 13]. Salmonella enterica strains with mutations in crp either alone or in combination with other genes have served as effective vaccine candidates against salmonellosis [28, 29]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
