Definition of genetically distinct attenuation mechanisms in naturally virulence-attenuated Listeria monocytogenes by comparative cell culture and molecular characterization.

ABSTRACT: Listeria monocytogenes is a foodborne pathogen able to cause serious disease in humans and animals. Not all isolates are equally pathogenic, however, and several isolates have been characterized as naturally virulence attenuated. We sought to identify the genetic basis of natural virulence attenuation using cell culture assays and molecular techniques. By comparing the phenotypes of naturally virulence-attenuated isolates to those of defined virulence gene mutants in plaque, cytotoxicity, and hemolysis assays and by characterizing selected virulence genes and their expression using DNA sequencing and TaqMan reverse transcriptase PCR, we classified virulence-attenuated isolates into four categories. Both group A and group B isolates were noncytotoxic and nonhemolytic; however, group A isola

SUBMITTER: Roberts A 

PROVIDER: S-EPMC1168991 | biostudies-literature | 2005 Jul

REPOSITORIES: biostudies-literature