OpnS, an outer membrane porin of Xenorhabdus nematophila, confers a competitive advantage for growth in the insect host. J Bacteriol 2009 Sep;191(17):5471-9
Date
05/26/2009Pubmed ID
19465651Pubmed Central ID
PMC2725620DOI
10.1128/JB.00148-09Scopus ID
2-s2.0-68949149828 (requires institutional sign-in at Scopus site) 8 CitationsAbstract
The gammaproteobacterium Xenorhabdus nematophila engages in a mutualistic association with an entomopathogenic nematode and also functions as a pathogen toward different insect hosts. We studied the role of the growth-phase-regulated outer membrane protein OpnS in host interactions. OpnS was shown to be a 16-stranded beta-barrel porin. opnS was expressed during growth in insect hemolymph and expression was elevated as the cell density increased. When wild-type and opnS deletion strains were coinjected into insects, the wild-type strain was predominantly recovered from the insect cadaver. Similarly, an opnS-complemented strain outcompeted the DeltaopnS strain. Coinjection of the wild-type and DeltaopnS strains together with uncolonized nematodes into insects resulted in nematode progeny that were almost exclusively colonized with the wild-type strain. Likewise, nematode progeny recovered after coinjection of a mixture of nematodes carrying either the wild-type or DeltaopnS strain were colonized by the wild-type strain. In addition, the DeltaopnS strain displayed a competitive growth defect when grown together with the wild-type strain in insect hemolymph but not in defined culture medium. The DeltaopnS strain displayed increased sensitivity to antimicrobial compounds, suggesting that deletion of OpnS affected the integrity of the outer membrane. These findings show that the OpnS porin confers a competitive advantage for the growth and/or the survival of X. nematophila in the insect host and provides a new model for studying the biological relevance of differential regulation of porins in a natural host environment.
Author List
van der Hoeven R, Forst SAuthor
Steven Forst PhD Professor in the Biological Sciences department at University of Wisconsin - MilwaukeeMESH terms used to index this publication - Major topics in bold
AnimalsBacterial Outer Membrane Proteins
Gene Deletion
Gene Expression Profiling
Genetic Complementation Test
Hemolymph
Insecta
Nematoda
Porins
Virulence
Virulence Factors
Xenorhabdus