Open AccessAnalysis of the Role of OpuC, an Osmolyte Transport System, in Salt Tolerance and Virulence Potential of Listeria monocytogenes
Author(s) -
Roy D. Sleator,
Jeroen A. Wouters,
Cormac G. M. Gahan,
Tjakko Abee,
Colin Hill
Publication year - 2001
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.67.6.2692-2698.2001
Subject(s) - listeria monocytogenes , listeria , osmolyte , virulence , microbiology and biotechnology , biology , betaine , bacteria , pathogen , operon , glycine , mutant , biochemistry , amino acid , genetics , gene
The success of Listeria monocytogenes as a food-borne pathogen owes much to its ability to survive a variety of stresses, both in the external environment prior to ingestion and subsequently within the animal host. Growth at high salt concentrations and low temperatures is attributed mainly to the accumulation of organic solutes such as glycine betaine and carnitine. We utilized a novel system for generating chromosomal mutations (based on a lactococcal pWVO1-derived Ori(+) RepA(-) vector, pORI19) to identify a listerial OpuC homologue. Mutating the operon in two strains of L. monocytogenes revealed significant strain variation in the observed activity of OpuC. Radiolabeled osmolyte uptake studies, together with growth experiments in defined media, linked OpuC to carnitine and glycine betaine uptake in Listeria. We also investigated the role of OpuC in contributing to the growth and survival of Listeria in an animal (murine) model of infection. Altering OpuC resulted in a significant reduction in the ability of Listeria to colonize the upper small intestine and cause subsequent systemic infection following peroral inoculation.