Regulation of autoinducer production in Salmonella typhimurium.

TitleRegulation of autoinducer production in Salmonella typhimurium.
Publication TypeJournal Article
Year of Publication1999
AuthorsSurette, MG, Bassler, BL
JournalMol Microbiol
Volume31
Issue2
Pagination585-95
Date Published1999 Jan
ISSN0950-382X
Keywords4-Butyrolactone, Bacterial Proteins, Glucose, Homoserine, Hydrogen-Ion Concentration, Lactones, Repressor Proteins, Salmonella typhimurium, Trans-Activators
Abstract

<p>Salmonella typhimurium strain LT2 secretes an organic signalling molecule that can be assayed by its ability to activate one of two specific quorum-sensing systems in Vibrio harveyi. Maximal activity is produced during mid- to late exponential phase when S. typhimurium is grown in the presence of glucose or other preferred carbohydrates. The signal is degraded by the onset of stationary phase or when the carbohydrate is depleted from the medium. Presumably, quorum sensing in S. typhimurium is operational during periods of rapid, nutrient-rich growth. Protein synthesis is required for degradation of the activity, suggesting that a complex regulatory circuitry controls signal production and detection in S. typhimurium. Increased signalling activity is observed if, after growth in the presence of glucose, S. typhimurium is transferred to a high-osmolarity (0.4 M NaCl) or to a low-pH (pH 5.0) environment. Degradation of the signal is induced by conditions of low osmolarity (0.1 M NaCl). High osmolarity and low pH are two conditions encountered by S. typhimurium cells when they undergo the transition to a pathogenic existence inside a host organism, suggesting that quorum sensing may have a role in the regulation of virulence in S. typhimurium.</p>

Alternate JournalMol. Microbiol.
PubMed ID10027975