Outer membrane vesicles of Pasteurella multocida contain virulence factors

Abstract

Pasteurella multocida (Pm) is a gram-negative bacterium able to infect different animal species, including human beings. This bacterium causes economic losses to the livestock industry because of its high morbidity and mortality in animals. In this work, we report the characterization of outer membrane vesicles (OMVs) released into the culture medium by different Pm serogroups. Purified OMVs in the range of 50–300 nm were observed by electron microscopy. Serum obtained from chickens infected with Pm recognized several proteins from Pm OMVs. Additionally, rabbit antiserum directed against a secreted protease from Actinobacillus pleuropneumoniae recognized a similar protein in the Pm OVMs, suggesting that OMVs from these bacterial species contain common immunogenic proteins. OmpA, a multifunctional protein, was identified in OMVs from different Pm serogroups, and its concentration was twofold higher in OMVs from Pm serogroups B and D than in OMVs from other serogroups. Three outer membrane proteins were also identified: OmpH, OmpW, and transferrin-binding protein. Three bands of 65, 110, and 250 kDa with proteolytic activity were detected in Pm OMVs of serogroups A and E. Additionally, β-lactamase activity was detected only in OMVs from Pm 12945 Ampr (serogroup A). Pm OMVs may be involved in different aspects of disease pathogenesis.

Genetic and Phylogenetic Characteristics of Pasteurella multocida Isolates From Different Host Species

“…Therefore, molecular typing methods have been developed to help assign P. multocida into five capsular genotypes (A, B, D, E, F) (Townsend et al, 2001 ) and eight LPS genotypes (L1-L8) (Harper et al, 2015 ). In addition, the multilocus sequence typing method has been also designed for P. multocida (Subaaharan et al, 2010 ), and it has been widely used in epidemiology and surveillance (Hotchkiss et al, 2011 ; Moustafa et al, 2013 ; Fernández-Rojas et al, 2014 ; Peng et al, 2018 ).…”

Transcriptomic Analysis of High- and Low-Virulence Bovine Pasteurella multocida in vitro and in vivo

“…As the main structure of the outer membrane of gram-negative bacteria, OMPs (e.g., membrane structural proteins, membrane transport proteins, membrane-bound proteins, and lipoproteins) play an important role in bacterial infection and pathogenic processes, such as adhesion, invasion, and intracellular survival ( 41 – 43 ). For example, OmpH and OmpA are the most typical virulence factors of P. multocida ( 44 , 45 ). OmpA and OmpP5 (outer membrane protein P5) were significantly upregulated in PmCQ2-m/PmCQ2 and PmCQ6-m/PmCQ6, and OmpP5 was increased in PmCQ2-m/PmCQ6-m.…”

The outer membrane phospholipase A is essential for membrane integrity and type III secretion in Shigella flexneri

“…A particularly important mechanism is vesiculation, where the outer membrane vesicles (OMVs) bud from the OM; these vesicles contain the OM and entrapped periplasmic contents [ 46 ]. Various OMPs were observed in the OMV proteomes from bacteria, such as Pasteurella multocida [ 47 ] and Vibrio cholerae [ 48 ]. Through proteomic analysis, PldA was detected in the OMV of S. flexneri [ 49 ].…”