RRC ID 35655
Author Waligora EA, Fisher CR, Hanovice NJ, Rodou A, Wyckoff EE, Payne SM.
Title Role of intracellular carbon metabolism pathways in Shigella flexneri virulence.
Journal Infect Immun
Abstract Shigella flexneri, which replicates in the cytoplasm of intestinal epithelial cells, can use the Embden-Meyerhof-Parnas, Entner-Doudoroff, or pentose phosphate pathway for glycolytic carbon metabolism. To determine which of these pathways is used by intracellular S. flexneri, mutants were constructed and tested in a plaque assay for the ability to invade, replicate intracellularly, and spread to adjacent epithelial cells. Mutants blocked in the Embden-Meyerhof-Parnas pathway (pfkAB and pykAF mutants) invaded the cells but formed very small plaques. Loss of the Entner-Doudoroff pathway gene eda resulted in small plaques, but the double eda edd mutant formed normal-size plaques. This suggested that the plaque defect of the eda mutant was due to buildup of the toxic intermediate 2-keto-3-deoxy-6-phosphogluconic acid rather than a specific requirement for this pathway. Loss of the pentose phosphate pathway had no effect on plaque formation, indicating that it is not critical for intracellular S. flexneri. Supplementation of the epithelial cell culture medium with pyruvate allowed the glycolysis mutants to form larger plaques than those observed with unsupplemented medium, consistent with data from phenotypic microarrays (Biolog) indicating that pyruvate metabolism was not disrupted in these mutants. Interestingly, the wild-type S. flexneri also formed larger plaques in the presence of supplemental pyruvate or glucose, with pyruvate yielding the largest plaques. Analysis of the metabolites in the cultured cells showed increased intracellular levels of the added compound. Pyruvate increased the growth rate of S. flexneri in vitro, suggesting that it may be a preferred carbon source inside host cells.
Volume 82(7)
Pages 2746-55
Published 2014-7-1
DOI 10.1128/IAI.01575-13
PII IAI.01575-13
PMID 24733092
PMC PMC4097621
MeSH Bacterial Proteins / genetics Bacterial Proteins / metabolism* Carbon / metabolism* Gene Expression Regulation, Bacterial / physiology Glucose / metabolism Humans Mutation Pentose Phosphate Pathway Protein Array Analysis Pyruvic Acid / metabolism Shigella flexneri / metabolism* Shigella flexneri / pathogenicity* Signal Transduction / physiology* Virulence
IF 3.201
Times Cited 19
Prokaryotes E. coli JW0120-KC JW1666-KC JW1839-KC JW1840-KC JW1841-KC JW1843-KC JW3887-KC JW5280-KC JW3400-KC