title: Expression of virulence and stress response genes in Aeromonas hydrophila under various stress conditions.
abstract: Aeromonas hydrophila has emerged as an important human pathogen as it causes gastroenteritis and extra-intestinal infections. Information regarding the influence of environmental stresses on gene expression profile of A. hydrophila is lacking. The impact of nutrient replenishment, nutrient deprivation, acid stress, and cold shock on housekeeping, general stress-response, and virulence genes was studied using quantitative real-time PCR in two A. hydrophila strains, CECT 839T, and A331. These sub-lethal stresses invoked significant changes in the expression of these genes in a strain-dependent manner. Overall, nutrient replenishment and deprivation significantly induced the expression of housekeeping (rpoD), general stress regulators (uspA and rpoS), and virulence (aer) genes, indicating their importance in regulating the survival and virulence of A. hydrophila under these stress conditions. rpoS gene was significantly induced under cold shock; whereas, acid stress significantly induced the expression of uspA gene. This is the first study to investigate the effect of environmental parameters on the expression of stress-response and virulence genes in A. hydrophila strains.
authors.affiliation: Food Technology Division, Bhabha Atomic Research Centre, Mumbai, India. vnagar@barc.gov.in.
authors.forename: Vandan
authors.initials: V
authors.lastname: Nagar
authors.affiliation: Food Technology Division, Bhabha Atomic Research Centre, Mumbai, India.
authors.forename: Jayant R
authors.initials: JR
authors.lastname: Bandekar
authors.affiliation: Food Technology Division, Bhabha Atomic Research Centre, Mumbai, India.
authors.forename: Ravindranath
authors.initials: R
authors.lastname: Shashidhar
mesh_terms: D016980:Aeromonas hydrophila / Q000235:genetics / Q000472:pathogenicity*; D001426:Bacterial Proteins / Q000096:biosynthesis*; D058639:Cold-Shock Response; D012321:DNA-Directed RNA Polymerases / Q000096:biosynthesis*; D020869:Gene Expression Profiling; D006360:Heat-Shock Proteins / Q000096:biosynthesis*; D012808:Sigma Factor / Q000096:biosynthesis*; D013217:Starvation; D013312:Stress, Physiological; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D006360:Heat-Shock Proteins; D012808:Sigma Factor; D037521:Virulence Factors; C069567:sigma factor KatF protein, Bacteria; C078564:universal stress protein A, Bacteria; D012321:DNA-Directed RNA Polymerases
keywords: Aeromonas hydrophila; Quantitative real-time PCR; Stress conditions