Resuscitation of the viable but non-culturable state of Salmonella enterica serovar Oranienburg by recombinant resuscitation-promoting factor derived from Salmonella Typhimurium strain LT2

• Published in: International journal of food microbiology Vol. 106; no. 3; pp. 241 - 247
• Main Authors: Panutdaporn, N., Kawamoto, K., Asakura, H., Makino, S.-I.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.02.2006; Elsevier
• Subjects: Amino Acid Sequence; Animals; bacterial contamination; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - pharmacology; Base Sequence; Biological and medical sciences; Blotting, Western; Cloning, Molecular; Colony Count, Microbial; Culture Media; Cytokines - chemistry; Cytokines - genetics; Cytokines - pharmacology; Dose-Response Relationship, Drug; Electrophoresis, Polyacrylamide Gel; Escherichia coli; food contamination; Food industries; Food Microbiology; food pathogens; Fundamental and applied biological sciences. Psychology; gene banks; Gene Expression Regulation, Bacterial; genes; microbial resuscitation; Micrococcus luteus; Molecular Sequence Data; nucleotide sequences; Osmotic Pressure; osmotic treatment; osmotolerance; Rabbits; recombinant fusion proteins; Recombinant Proteins - chemistry; Recombinant Proteins - genetics; Recombinant Proteins - pharmacology; Resuscitation-promoting factor; Salmonella enterica; Salmonella enterica - drug effects; Salmonella enterica - growth & development; Salmonella enterica serovar Oranienburg; Salmonella enterica subsp. enterica serovar Oranienburg; Salmonella Food Poisoning - microbiology; Salmonella typhimurium; Salmonella typhimurium - chemistry; Salmonella typhimurium - genetics; Salmonella Typhimurium LT2; Serial Passage; sodium chloride; Sodium Chloride - pharmacology; stress tolerance; TATA box; Time Factors; viability; Viable but non-culturable state; Viable but non-culturable state; Salmonella enterica serovar Oranienburg; Salmonella Typhimurium LT2; Resuscitation-promoting factor; Bacteria; Salmonella typhimurium; Viability; Salmonella oranienburg; Enterobacteriaceae; Strain
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2005.06.022

A gene encoding the resuscitation-promoting factor (Rpf) from Salmonella Typhimurium LT2 was cloned and characterized. The amino acid sequence encoded by S. Typhimurium LT2 rpf gene shares 24.2% homology with Micrococcus luteus Rpf, which is secreted by growing cells, and required to resuscitate from viable but non-culturable (VNC) state. The S. Typhimurium LT2 rpf gene is 696 bp long, and shared a conserved segment with Salmonella enterica serovar Oranienburg (99.4%). Recombinant Rpf (rRpf) proteins of S. Typhimurium LT2 after expression in E. coli BL21 harboring the pET15-b plasmid was approximately 25 kDa. Since S. Oranienburg cells are relatively quick to enter the VNC state just after incubating in the presence of 7% NaCl at 37 °C for 3 days, we evaluated the biological effect of rRpf by using S. Oranienburg VNC cells. The rRpf not only promoted proliferation but also induced resuscitation of VNC cells to the culturable state in a dose-dependent manner. Therefore, rRpf may be useful for detection of bacterial contaminants present in the VNC form in food samples and the environment.