Phenotypic Variations and Molecular Identification of Salmonella enterica Serovar Typhimurium Cells Under Starvation in Seawater

Abstract

In seawater, enteric bacteria evolve toward a stressed state that is difficult to identify because of major alterations of their phenotype. In this study, we incubated four reference strains of S. enterica serovar Typhimurium in seawater microcosms for 10 months and studied the modifications of their main phenotypic characters. All of the strains lost some key characters used for traditional identification of the Salmonella genus. They became able to produce acetoin, and tryptophane deaminase activity became positive, but they lost the capacity to use rhamnose. We were able to show some modifications of the level of enzymatic profile as well as in their antibiotic susceptibility. The atypical cells of S. enterica serovar Typhimurium were identified by polymerase chain reaction (PCR) methods using the internal transcribed spacer region, and they were confirmed by multiplex PCR after the simultaneous amplification of the phoP, Hin, and H-li genes.

Controlled adhesion of Salmonella Typhimurium to poly(oligoethylene glycol methacrylate) grafts

“…[14] The polymer grafts were prepared by atom transfer radical polymerization (ATRP) initiated by diazoniummodified substrates instead of the traditional methods employing grafted initiators from self assembled monolayers of thiols on gold [7] or silanes on glass. [8] Towards this end, ATRP initiators were electrografted to gold via the electrochemical reduction of the noncommercial diazonium salt BF 4 − , + N 2 -C 6 H 4 -CH(CH 3 )Br to provide Au-C 6 H 4 -CH(CH 3 )Br plates (Au-Br) serving as macroinitiators for the ATRP of oligoethylene glycol methacrylate.…”

Starvation survival of Candida albicans in various water microcosms

“…Lacks of nutrients in natural ecosystem are often limiting factor for microbial population. Viability of starved cells has been largely studied in our laboratory for Salmonella enterica Serovar Typhimurium [25]; Vibrio alginolyticus [26]; Citrobacter [27]; Vibrio fluvialis [28]; Vibrio parahaemolyticus [29] and Shigella spp. [30].…”

Virulence gene expression, proteins secreted and morphological alterations of Vibrio parahaemolyticus and Vibrio alginolyticus in response to long-term starvation in seawater

“…As a consequence, a general increase in virulence and resistance against stress and chemotherapic as well as antibiotic agents is typically observed (Givskov et al, 1994). One of the most frequently observed behaviours in the nutrient starvation response of Gram-negative bacteria is the size reduction and cell morphology conversion from rod to coccoid shape (Ben Abdallah et al, 2007;Kjelleberg et al, 1993).…”