Date of Award
Master of Science
A small fraction of bacterial populations consist of "persistent" cells that are phenotypically distinct from the majority of cells by their ability to avoid killing by a variety of antimicrobial challenges. Persistence is distinct from resistance in that persistent cells are unable to grow in the presence of the antimicrobial agent or treatment, but resume growth after the selection has been removed. Presently, little is known about the genetic or physiological basis of persistence. In this study we demonstrate that Salmonella enterica serovar Typhimurium (S. typhimurium) displays the persistence phenotype. To better understand persistence in this important food-borne pathogen, we have isolated 6 mutants that show an increased ability to survive exposure to a variety of antibiotics without an increase in MIC values. All of the mutants isolated were found to have an extended lag phase, but had wild type growth rates in exponential phase. Characterization of the mutants indicates that multiple loci appear to contribute to persistence. Mapping the genes for the high persistence phenotype will reveal new insights into this widely observed phenomenon.
Andrew Richard Slattery
Slattery, Andrew Richard, "Isolation and characterization of high persistence mutants of Salmonella enterica serotype Typhimurium" (2006). Retrospective Theses and Dissertations. 17534.