The Acid Tolerance Response of Salmonella spp.: An adaptive strategy to survive in stressful environments prevailing in foods and the host

Acid and low temperature treatments on Salmonella Enteritidis inoculated in pork and its subsequent survival in simulated gastric fluid

“…To colonize the host, S. enterica must overcome the acidity of the stomach, the microbial flora of the gut, and the intestinal barrier in the host (ÁLVAREZ-ORDÓÑEZ et al, 2012 most prevalent serovar among the brazilian human population (ROWLANDS et al, 2014). Although the main source of Salmonella are eggs and egg products (GANTOIS et al, 2009), other foods such as raw milk, beef and pork was associated to S. enterica infection outbreaks (ROWLANDS et al, 2014;CDC, 2015).…”

“…Strategies used in abattoirs to prevent S. enterica growth include lower storage temperatures and surface decontamination using acids (SUN et al, 2003;PIPEK et al, 2006). Although these strategies create environments of moderate stress, S. enterica is capable of adapting to these adverse conditions, not only in natural environments in animal or human hosts, but also in commercial ones such as abattoirs and food industries (WINFIELD & GROISMAN, 2003;ÁLVAREZ-ORDÓÑEZ et al, 2012).…”

Expression of ompR gene in the acid adaptation and thermal resistance of Salmonella Enteritidis SE86

“…Most studies have focused the log-phase ATR system to be induced when exponentially growing cells suddenly undergo a rapid transition to low pH [5]. More than 50 acid shock proteins (ASP) are produced during this response [6]. The regulatory gene rpoS, encoding an alternative sigma factor, is required for log-phase acid tolerance and for control of the production of clusters of ASPs [6,3].…”

“…More than 50 acid shock proteins (ASP) are produced during this response [6]. The regulatory gene rpoS, encoding an alternative sigma factor, is required for log-phase acid tolerance and for control of the production of clusters of ASPs [6,3].…”

“…It is distinct from the general stress response system that is induced by entry into the stationary phase regardless of the culture pH. The general stress response system requires stationaryphase induction of the alternative sigma factor, while the acid-induced stationary-phase ATR does not [6,3]. Thus, OmpR is a stationary-phase ASP.…”