Identification of the outer-membrane protein PagC required for the serum resistance phenotype in Salmonella enterica serovar Choleraesuis

Microbiology ◽  
2005 ◽  
Vol 151 (3) ◽  
pp. 863-873 ◽  
Author(s):  
Miki Nishio ◽  
Nobuhiko Okada ◽  
Tsuyoshi Miki ◽  
Takeshi Haneda ◽  
Hirofumi Danbara
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Salmonella Enterica ◽  
Pathogenic Bacteria ◽  
Insertional Mutagenesis ◽  
Genomic Library ◽  
Serum Resistance ◽  
Resistance Phenotype ◽  
Systemic Infections

Serum resistance is a crucial virulence factor for the development of systemic infections, including bacteraemia, by many pathogenic bacteria. Salmonella enterica serovar Choleraesuis is an important enteric pathogen that causes serious systemic infections in swine and humans. Here, it was found that, when introduced into Escherichia coli, a recombinant plasmid carrying the pagC gene from a plasmid-based genomic library of S. enterica serovar Choleraesuis conferred a high-level resistance to the bactericidal activity of pooled normal swine serum. The resistance was equal to the level conferred by rck, a gene encoding a 17 kDa outer-membrane protein which promotes the serum resistance phenotype in S. enterica serovar Typhimurium. Insertional mutagenesis of the cloned pagC gene generated a mutation that resulted in the loss of the serum resistance phenotype in E. coli. When this mutation was introduced into the chromosome of S. enterica serovar Choleraesuis by homology recombination with the wild-type allele, the resulting strain could not produce PagC, and it showed a decreased level of resistance to complement-mediated killing. The mutation could be restored by introduction of the intact pagC gene on a plasmid, but not by introduction of the point-mutated pagC gene. In addition, PagC was able to promote serum resistance in the S. enterica serovar Choleraesuis LPS mutant strain, which is highly sensitive to serum killing. Although PagC is not thought to confer serum resistance directly, these results strongly suggest that PagC is an important outer-membrane protein that plays an important role in the serum resistance of S. enterica serovar Choleraesuis.

scholarly journals Serum resistance in Haemophilus parasuisSC096 strain requires outer membrane protein P2 expression

2011 ◽  
Vol 326 (2) ◽  
pp. 109-115 ◽  
Author(s):  
Bin Zhang ◽  
Saixiang Feng ◽  
Chenggang Xu ◽  
Suming Zhou ◽  
Yanbing He ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Serum Resistance

scholarly journals Putative Riemerella anatipestifer Outer Membrane Protein H Affects Virulence

2021 ◽  
Vol 12 ◽  
Author(s):  
Qun Gao ◽  
Shuwei Lu ◽  
Mingshu Wang ◽  
Renyong Jia ◽  
Shun Chen ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Pathogenic Bacteria ◽  
Lethal Dose ◽  
Protein A ◽  
Economic Losses ◽  
Wild Type ◽  
Riemerella Anatipestifer ◽  
Similar Growth

Riemerella anatipestifer causes serious contagious disease in ducks, geese, and other fowl. However, as a harmful pathogen causing significant economic losses in the poultry industry, R. anatipestifer is still poorly understood for its pathogenesis mechanisms. In a previous study, we developed an indirect ELISA method for detecting R. anatipestifer infection using B739_0832 protein, a putative outer membrane protein H (OmpH) that is conserved among different serotypes of R. anatipestifer. Although OmpH in some pathogenic bacteria, such as Pasteurella, has been reported as a virulence factor, it is still not clear whether B739_0832 protein contributes to the virulence of R. anatipestifer. In this study, we confirmed that B739_0832 protein in R. anatipestifer localizes to the outer membrane. We constructed a B739_0832 deletion mutant strain (ΔB739_0832) and assayed various effects from the deletion of B739_0832. ΔB739_0832 strain had a similar growth rate to wild-type R. anatipestifer CH-1. However, the survival rate of ducklings in 10 days after infection from ΔB739_0832 strain was 50%, whereas no ducklings survived from wild-type R. anatipestifer infection. Furthermore, the median lethal dose (LD50) of the ΔB739_0832 strain was approximately 150 times higher than that of the wild-type strain. Pathology examinations on infected ducklings found that, at 36 h after infection, bacterial loads in blood, liver, and brain tissues from ΔB739_0832-infected ducklings were considerably lower than those from wild-type infected ducklings. These results demonstrate that the B739_0832 protein contributes to the virulence of R. anatipestifer CH-1.

scholarly journals Resistance of Yersinia pestis to Complement-Dependent Killing Is Mediated by the Ail Outer Membrane Protein

2007 ◽  
Vol 76 (2) ◽  
pp. 612-622 ◽  
Author(s):  
Sara Schesser Bartra ◽  
Katie L. Styer ◽  
Deanna M. O'Bryant ◽  
Matthew L. Nilles ◽  
B. Joseph Hinnebusch ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Yersinia Pestis ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Pathogenic Bacteria ◽  
Outer Membrane Proteins ◽  
Mouse Serum ◽  
Bacterial Killing ◽  
High Level

ABSTRACT Yersinia pestis, the causative agent of plague, must survive in blood in order to cause disease and to be transmitted from host to host by fleas. Members of the Ail/Lom family of outer membrane proteins provide protection from complement-dependent killing for a number of pathogenic bacteria. The Y. pestis KIM genome is predicted to encode four Ail/Lom family proteins. Y. pestis mutants specifically deficient in expression of each of these proteins were constructed using lambda Red-mediated recombination. The Ail outer membrane protein was essential for Y. pestis to resist complement-mediated killing at 26 and 37°C. Ail was expressed at high levels at both 26 and 37°C, but not at 6°C. Expression of Ail in Escherichia coli provided protection from the bactericidal activity of complement. High-level expression of the three other Y. pestis Ail/Lom family proteins (the y1682, y2034, and y2446 proteins) provided no protection against complement-mediated bacterial killing. A Y. pestis ail deletion mutant was rapidly killed by sera obtained from all mammals tested except mouse serum. The role of Ail in infection of mice, Caenorhabditis elegans, and fleas was investigated.

scholarly journals Outer Membrane Protein X (Ail) Contributes to Yersinia pestis Virulence in Pneumonic Plague and Its Activity Is Dependent on the Lipopolysaccharide Core Length

2010 ◽  
Vol 78 (12) ◽  
pp. 5233-5243 ◽  
Author(s):  
Anna M. Kolodziejek ◽  
Darren R. Schnider ◽  
Harold N. Rohde ◽  
Andrzej J. Wojtowicz ◽  
Gregory A. Bohach ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Yersinia Pestis ◽  
Outer Membrane ◽  
Rat Model ◽  
Outer Membrane Protein ◽  
Serum Resistance ◽  
Wild Type ◽  
Time To Death ◽  
Protein X

ABSTRACT Yersinia pestis, the causative agent of plague, is one of the most virulent microorganisms known. The outer membrane protein X (OmpX) in Y. pestis KIM is required for efficient bacterial adherence to and internalization by cultured HEp-2 cells and confers resistance to human serum. Here, we tested the contribution of OmpX to disease progression in the fully virulent Y. pestis CO92 strain by engineering a deletion mutant and comparing its ability in mediating pneumonic plague to that of the wild type in two animal models. The deletion of OmpX delayed the time to death up to 48 h in a mouse model and completely attenuated virulence in a rat model of disease. All rats challenged with 1 × 108 CFU of the ompX mutant survived, compared to the 50% lethal dose (LD50) of 1.2 × 103 CFU for the wild-type strain. Because murine serum is not bactericidal for the ompX mutant, the mechanism underlying the delay in time to death in mice was attributed to loss of adhesion/internalization properties but not serum resistance. The rat model, which is most similar to humans, highlighted the critical role of serum resistance in disease. To resolve conflicting evidence for the role of Y. pestis lipopolysaccharide (LPS) and OmpX in serum resistance, ompX was cloned into Escherichia coli D21 and three isogenic derivatives engineered to have progressively truncated LPS core saccharides. OmpX-mediated serum resistance, adhesiveness, and invasiveness, although dependent on LPS core length, displayed these functions in E. coli, independently of other Yersinia proteins and/or LPS. Also, autoaggregation was required for efficient OmpX-mediated adhesiveness and internalization but not serum resistance.

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