Functional properties of the major outer membrane protein in Stenotrophomonas maltophilia

Abstract

Stenotrophomonas maltophilia is an opportunistic pathogen that is closely associated with high morbidity and mortality in debilitated and immunocompromised individuals. Therefore, to investigate the pathogenesis mechanism is urgently required. However, there are very few studies to evaluate the functional properties of outer membrane protein, which may contribute to the pathogenesis in S. maltophilia. In this study, three abundant proteins in the outer membrane fraction of S. maltophilia were identified by liquid chromatography-tandem mass spectrometry as OmpW1, MopB, and a hypothetical protein. MopB, a member of the OmpA family, was firstly chosen for functional investigation in this study because many OmpA-family proteins are known to be involved in pathogenesis and offer potential as vaccines. Membrane fractionation analyses demonstrated that MopB was indeed the most abundant outer membrane protein (OMP) in S. maltophilia. For functional studies, the mopB mutant of S. maltophilia (SmMopB) was constructed by insertional mutation. MopB deficiency resulted in a change in the protein composition of OMPs and altered the architecture of the outer membrane. The SmMopB strain exhibited reduced cytotoxicity toward L929 fibroblasts and was more sensitive to numerous stresses, including human serum, sodium dodecyl sulfate, and hydrogen peroxide compared with wildtype S. maltophilia. These results suggest that MopB may be a good candidate for the design of vaccines or anti-MopB drugs for controlling serious nosocomial infections of multidrug-resistant S. maltophilia, especially in immunosuppressed patients.

σ P -NagA-L1/L2 Regulatory Circuit Involved in ΔompA 299-356 -Mediated Increase in β-Lactam Susceptibility in Stenotrophomonas maltophilia

“…The known mechanisms responsible for the β-lactam resistance of S. maltophilia can be classified into β-lactamase-mediated resistance and non-β-lactamase-mediated resistance ( 33 , 34 ). The β-lactamase activities of KJ, KJΔOmpA 299-356 , and KJL2-OmpAΔOmpA 299-356 were determined to assess the involvement of β-lactamases in the Δ ompA 299-356 -mediated increase in β-lactam susceptibility.…”

“…OmpA (Smlt0955) of S. maltophilia is known to be the highly expressed gene in logarithmically grown S. maltophilia ( 15 , 33 ). The relationship between ompA deletion, swimming compromise, and conjugation failure has been reported in our recent study ( 15 ).…”

Intranasal immunization with recombinant outer membrane protein A induces protective immune response against Stenotrophomonas maltophilia infection

“…maltophilia and contribute to maintenance of cell membrane structure, and bacterial adhesion, and S . maltophilia with the MopB gene deletion cause milder L929 cell cytotoxicity compared with the wild type bacteria [24]. However, whether OmpA in S .…”