A derivative of Tn5 was used to construct a variety of stable insertion mutations in the entomopathogenic bacterium, Xenorhabdus bovzenii T228/ 1. Mutants which had altered expression of Congo Red binding ability, ampicillin resistance, haemolytic activity and lecithinase were isolated. Isolates with altered lecithinase activity had either lost ability to produce this enzyme or showed reduced expression. The role of lecithinase in pathogenesis of X . bovzenii T228/ 1 for Galleria mellonella larvae was examined by LD,, analysis. Maximum killing of G. mellonella was observed at 72 h post infection for both the wild-type parent strain and a lecithinase mutant 34(45). However, the LD," value for the wild-type parent strain (8.7 cells per larva) was significantly less than that calculated for the lecithinase mutant (35.5 cells per larva). The data suggested that although lecithinase is a virulence factor produced by X . bovienii, lecithinase activity alone is not sufficient for killing of G. mellonella larvae.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.