title: Proteomic analysis of the response of Listeria monocytogenes to bile salts under anaerobic conditions.
abstract: Listeria monocytogenes is a food-borne pathogen responsible for the disease listeriosis. The infectious process depends on survival in the high bile-salt conditions encountered throughout the gastrointestinal tract, including the gallbladder. However, it is not clear how bile-salt resistance mechanisms are induced, especially under physiologically relevant conditions. This study sought to determine how the L. monocytogenes strains EGDe (serovar 1/2a), F2365 (serovar 4a) and HCC23 (serovar 4b) respond to bile salts under anaerobic conditions. Changes in the expressed proteome were analysed using multidimensional protein identification technology coupled with electrospray ionization tandem mass spectrometry. In general, the response to bile salts among the strains tested involved significant alterations in the presence of cell-wall-associated proteins, DNA repair proteins, protein folding chaperones and oxidative stress-response proteins. Strain viability correlated with an initial osmotic stress response, yet continued survival for EGDe and F2365 involved different mechanisms. Specifically, proteins associated with biofilm formation in EGDe and transmembrane efflux pumps in F2365 were expressed, suggesting that variations exist in how virulent strains respond and adapt to high bile-salt environments. These results indicate that the bile-salt response varies among these serovars and that further research is needed to elucidate how the response to bile salts correlates with colonization potential in vivo.
authors.affiliation: Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA.
authors.forename: Angela
authors.initials: A
authors.lastname: Payne
authors.affiliation: Animal Sciences Department, University of Nebraska, Lincoln, NE 68588, USA.
authors.forename: Ty B
authors.initials: TB
authors.lastname: Schmidt
authors.affiliation: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, USA.
authors.forename: Bindu
authors.initials: B
authors.lastname: Nanduri
authors.affiliation: Life Sciences and Biotechnology Institute, Mississippi State University, Mississippi State, MS 39762, USA.
authors.forename: Ken
authors.initials: K
authors.lastname: Pendarvis
authors.affiliation: Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA.
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Pittman
authors.affiliation: Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA.
authors.forename: Justin A
authors.initials: JA
authors.lastname: Thornton
authors.affiliation: Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Grissett
authors.affiliation: Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA.
authors.forename: Janet R
authors.initials: JR
authors.lastname: Donaldson
mesh_terms: D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001647:Bile Acids and Salts / Q000494:pharmacology*; D004260:DNA Repair / Q000235:genetics / Q000502:physiology; D004269:DNA, Bacterial; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000145:classification / Q000187:drug effects* / Q000378:metabolism*; D050296:Microbial Viability; D040901:Proteomics; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D021241:Spectrometry, Mass, Electrospray Ionization; D013312:Stress, Physiological
chemical_list: D001426:Bacterial Proteins; D001647:Bile Acids and Salts; D004269:DNA, Bacterial