Construction and characterization of a derivative of Neisseria gonorrhoeae strain MS11 devoid of all opa genes.

ABSTRACT: To better understand the role of Opa in gonococcal infections, we created and characterized a derivative of MS11 (MS11?opa) that had the coding sequence for all 11 Opa proteins deleted. The MS11?opa bacterium lost the ability to bind to purified lipooligosaccharide (LOS). While nonpiliated MS11?opa and nonpiliated Opa-expressing MS11 cells grew at the same rate, nonpiliated MS11?opa cells rarely formed clumps of more than four bacteria when grown in broth with vigorous shaking. Using flow cytometry analysis, we demonstrated that MS11?opa produced a homogeneous population of bacteria that failed to bind monoclonal antibody (MAb) 4B12, a MAb specific for Opa. Opa-expressing MS11 cells consisted of two predominant populations, where ?85% bound MAb 4B12 to a significant level and the other population bound little if any MAb. Approximately 90% of bacteria isolated from a phenotypically Opa-negative colony (a colony that does not refract light) failed to bind MAb 4B12; the remaining 10% bound MAb to various degrees. Piliated MS11?opa cells formed dispersed microcolonies on ME180 cells which were visually distinct from those of piliated Opa-expressing MS11 cells. When Opa expression was reintroduced into MS11?opa, the adherence ability of the strain recovered to wild-type levels. These data indicate that Opa contributes to both bacterium-bacterium and bacterium-host cell interactions.

SUBMITTER: LeVan A 

PROVIDER: S-EPMC3497525 | biostudies-literature | 2012 Dec

REPOSITORIES: biostudies-literature