General response of Salmonella enterica serovar Typhimurium to desiccation: A new role for the virulence factors sopD and sseD in survival.

摘要: Salmonella can survive for long periods under extreme desiccation conditions. This stress tolerance poses a risk food safety, but relatively little is known about the molecular and cellular regulation of this adaptation mechanism. To determine genetic components involved in Salmonella's response to desiccation, we performed global transcriptomic analysis comparing S. enterica serovar Typhimurium cells equilibrated low water activity (aw 0.11) high 1.0). The revealed that 719 genes were differentially regulated between two conditions, which 290 up-regulated at aw 0.11. Most these metabolic pathways, transporter regulation, DNA replication/repair, transcription translation, and, more importantly, virulence genes. Among these, decided focus on role sopD sseD. Deletion mutants created their ability exposure 0.11 was compared wild-type strain an E. coli O157:H7 strain. sseD exhibited significant cell viability reductions 2.5 1.3 Log (CFU/g), respectively, after 4 days glass beads. Additional differences observed 7 days. lost similarly mutants. Scanning electron microscopy showed both displayed different morphology production extracellular matrix same These findings suggested are required survival during desiccation.