HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Jørgensen, F. Articles by Humphrey, T. Search for Related Content PubMed PubMed Citation Articles by Jørgensen, F. Articles by Humphrey, T. Agricola Articles by Jørgensen, F. Articles by Humphrey, T.

Invasiveness in chickens, stress resistance and RpoS status of wild-type Salmonella enterica subsp. enterica serovar Typhimurium definitive type 104 and serovar Enteritidis phage type 4 strains

School of Biological Sciences, Food Sciences Division, University of Nottingham, Sutton Bonington Campus, Leicestershire LE12 5RD, UK¹
Centre for Applied Microbiology and Research (CAMR), Research Division, Porton Down, Salisbury SP4 0JG, UK²
PHLS Food Microbiology Food Research Unit, Church Lane, Heavitree, Exeter EX2 5AD, UK³

Author for correspondence: Frieda Jørgensen. Tel: +44 1392 402955. Fax: +44 1392 412835. e-mail: fjorgensen{at}phls.org.uk

The heat and acid resistance and the ability to survive airdrying on commonly used kitchen surfaces were assessed for clinical and environmental strains of Salmonella enterica subsp. enterica serovar Typhimurium, definitive type (DT) 104. Three out of thirty-eight strains of DT 104 were found to be more sensitive in stationary phase to the stresses examined than the other strains. This compares to a previous study by the authors which showed that seven out of forty serovar Enteritidis phage type (PT) 4 strains were more sensitive. RpoS activity was examined indirectly in selected strains of DT 104 and PT 4. In those with normal stress resistance a 100-fold induction of an RpoS-dependent spvR/A'::luxCDABE fusion was observed upon entry into stationary phase. The sensitive strains examined showed either no induction or a reduced level of spvR/A'::luxCDABE expression. The rpoS gene was sequenced from these strains and three were found to harbour mutations including one deletion, one base-pair substitution resulting in a nonsense codon, and one insertion causing a frameshift resulting in an early stop codon. Strains with negligible or reduced spvR/A'::luxCDABE expression had low stress resistance. All strains of DT 104 could be recovered from liver and spleen tissues of infected hens 14 d post-infection, but one with no induction of spvR/A'::luxCDABE expression was significantly less likely to be recovered from chicken reproductive tissues, liver or spleen than the majority of other strains, including one with reduced spvR/A'::luxCDABE expression. This work has demonstrated that clinical and environmental strains of DT 104 and PT 4 not infrequently harbour mutations in the rpoS allele. It is possible that the rpoS mutations may have occurred during the initial isolation of the strains. The ability of a strain to cause infection, however, also depends on factors such as host susceptibility and dose.

Keywords: spv-lux reporter, chicken reproductive tissue

Abbreviations: DT, definitive type; PT, phage type; RLU, relative light units (per ml)

^a Present address: PHLS Food Microbiology Food Research Unit, Church Lane, Heavitree, Exeter EX2 5AD, UK.

^b Professor Stewart sadly died in February 1999, at age 47.

This article has been cited by other articles:

				K. A. G. Karatzas, L. P. Randall, M. Webber, L. J. V. Piddock, T. J. Humphrey, M. J. Woodward, and N. G. Coldham Phenotypic and Proteomic Characterization of Multiply Antibiotic-Resistant Variants of Salmonella enterica Serovar Typhimurium Selected Following Exposure to Disinfectants Appl. Envir. Microbiol., March 1, 2008; 74(5): 1508 - 1516. [Abstract] [Full Text] [PDF]

				A. P. White and M. G. Surette Comparative Genetics of the rdar Morphotype in Salmonella J. Bacteriol., December 15, 2006; 188(24): 8395 - 8406. [Abstract] [Full Text] [PDF]

				C. Saint-Ruf, F. Taddei, and I. Matic Stress and Survival of Aging Escherichia coli rpoS Colonies Genetics, September 1, 2004; 168(1): 541 - 546. [Abstract] [Full Text] [PDF]

				T. A. Cogan, F. Jorgensen, H. M. Lappin-Scott, C. E. Benson, M. J. Woodward, and T. J. Humphrey Flagella and curli fimbriae are important for the growth of Salmonella enterica serovars in hen eggs Microbiology, April 1, 2004; 150(4): 1063 - 1071. [Abstract] [Full Text] [PDF]

				V. Robbe-Saule, G. Algorta, I. Rouilhac, and F. Norel Characterization of the RpoS Status of Clinical Isolates of Salmonella enterica Appl. Envir. Microbiol., August 1, 2003; 69(8): 4352 - 4358. [Abstract] [Full Text] [PDF]

				L. Notley-McRobb, T. King, and T. Ferenci rpoS Mutations and Loss of General Stress Resistance in Escherichia coli Populations as a Consequence of Conflict between Competing Stress Responses J. Bacteriol., February 1, 2002; 184(3): 806 - 811. [Abstract] [Full Text] [PDF]

				K. L. Mattick, F. Jorgensen, P. Wang, J. Pound, M. H. Vandeven, L. R. Ward, J. D. Legan, H. M. Lappin-Scott, and T. J. Humphrey Effect of Challenge Temperature and Solute Type on Heat Tolerance of Salmonella Serovars at Low Water Activity Appl. Envir. Microbiol., September 1, 2001; 67(9): 4128 - 4136. [Abstract] [Full Text] [PDF]