2. Academic Validation
  3. The Effect of Oxygen on Bile Resistance in Listeria monocytogenes

The Effect of Oxygen on Bile Resistance in Listeria monocytogenes

  • J Proteomics Bioinform. 2016 Apr;9(4):107-119. doi: 10.4172/jpb.1000396.
Morgan L Wright 1,  Ken Pendarvis 2,  Bindu Nanduri 3,  Mariola J Edelmann 4,  Haley N Jenkins 1,  Joseph S Reddy 3,  Jessica G Wilson 1,  Xuan Ding 5,  Paul R Broadway 6,  Mais G Ammari 2,  Oindrila Paul 1,  Brandy Roberts 1,  Janet R Donaldson 7
Affiliations

Affiliations

  • 1 Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA.
  • 2 School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ 85721, USA.
  • 3 Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, USA.
  • 4 Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA.
  • 5 Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA.
  • 6 Livestock Issues Research Unit, USDA-ARS, Lubbock, TX 79403, USA.
  • 7 Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA; The University of Southern Mississippi, 118 College Drive, Box #5018, Hattiesburg, USA.
PMID: 27274623 DOI: 10.4172/jpb.1000396
Abstract

Listeria monocytogenes is a Gram-positive facultative anaerobe that is the causative agent of the disease listeriosis. The infectious ability of this bacterium is dependent upon resistance to stressors encountered within the gastrointestinal tract, including bile. Previous studies have indicated bile salt hydrolase activity increases under anaerobic conditions, suggesting anaerobic conditions influence stress responses. Therefore, the goal of this study was to determine if reduced oxygen availability increased bile resistance of L. monocytogenes. Four strains representing three serovars were evaluated for changes in viability and proteome expression following exposure to bile in aerobic or anaerobic conditions. Viability for F2365 (serovar 4b), EGD-e (serovar 1/2a), and 10403S (serovar 1/2a) increased following exposure to 10% porcine bile under anaerobic conditions (P < 0.05). However, HCC23 (serovar 4a) exhibited no difference (P > 0.05) in bile resistance between aerobic and anaerobic conditions, indicating that oxygen availability does not influence resistance in this strain. The proteomic analysis indicated F2365 and EGD-e had an increased expression of proteins associated with cell envelope and membrane bioenergetics under anaerobic conditions, including thioredoxin-disulfide reductase and cell division proteins. Interestingly, HCC23 had an increase in several dehydrogenases following exposure to bile under aerobic conditions, suggesting that the NADH:NAD+ is altered and may impact bile resistance. Variations were observed in the expression of the cell shape proteins between strains, which corresponded to morphological differences observed by scanning electron microscopy. These data indicate that oxygen availability influences bile resistance. Further research is needed to decipher how these changes in metabolism impact pathogenicity in vivo and also the impact that this has on susceptibility of a host to listeriosis.

Keywords

Bile; Listeria monocytogenes; Mass spectrometry; Oxygen; Proteomic; Scanning electron microscopy.

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