This study suggests that chromosome rearrangements in the host-specific Salmonella enterica serovar Typhi, the causal agent of typhoid fever, occur within the human host over time. Unlike other strains of Salmonella that are primarily adapted to people, Salmonella enteritidis is primarily adapted to animal hosts, at least for the beginning of its life cycle. Salmonella includes a group of gram-negative bacillus bacteria that causes food poisoning and the consequent infection of the intestinal tract. Other imbalanced arrangement types were relatively rare, occurring only once within a set of colonies, as in the 1998 strain from carrier 1 and the first 1985 strain from carrier 2.
All lower taxonomy nodes (3,371) Common name i-Synonym i: Salmonella choleraesuis: Other names i ›ATCC 13312 [[Salmonella choleraesuis corrig.
While most Salmonella strains have a conserved chromosomal arrangement type, rearrangements are very common in host-specific Salmonella strains. Although the arrangement types of strains isolated from the same carrier at different time points varied depending on the carrier, strains isolated from the same carrier always had the same Vi phage type, suggesting that strains isolated from the same carrier were derived from a single infection. The uncontrolled activation of the host innate immune response can potentially lead to systematic inflammation, tissue injury, intravascular coagulation, and even death . Four mice were infected with strain 2250 (a pigeon-associated strain with the inversion), three mice were infected with strain 2248 (a pigeon-associated strain with the inversion), and three mice each were infected with fowl-specific There is a strong correlation between host restriction and These results indicate that these pigeon-associated strains of serovar Typhimurium share many of the qualities found in host-adapted strains.
This is the first time The data obtained from this study, together with observations from previous studies, suggest that these strains may represent a snapshot of an intermediate phase of evolution in which an organism evolves from a generalist strain to a host-specific strain.We thank Andreas Kresse for helpful discussions on this topic. We thank H. Gattermann, Vera Trute, Susanne Kulbe, H. Ragnit, and Brigitte Tannert for skillful technical assistance.R.A.H. 14. Pigeon-associated strains were gathered from various regions in Germany from 1997 through 2003, phage typed, and stored at the Robert Koch Institute in Wernigerode, Germany. FIG. Salmonella enteritidis is a rod-shaped, gram negative, non-motile bacteria, that does not form spores. However, there were notable exceptions.
(1998) report that oligopeptidase A also has a second protease activity, designated In, as … Most carrier 4 strains only had one rearrangement: an inversion of region 1 (Arrangement types and estimated replichore imbalance of This is an open-access article distributed under the terms of the Arrangement types of cultured colonies isolated from frozen stocksThe pattern of observed arrangement types, in particular the arrangement types found in the strains from carriers 1 and 4, suggests that rearrangements occurred Two explanations for this observation are that the carrier was originally infected with bacteria having different arrangement types and that rearrangements occur within the carrier over time. The observation that Fels-1 and Fels-2 are missing from these strains is not surprising, as similar results have been found in other serovar Typhimurium strains recently (Virulence of two pigeon-associated strains was assayed in BALB/c mice. For example, the carrier 1 strains isolated in 1993 and 1996 and the carrier 4 strain isolated in 1991 were estimated to have replichores that are up to 37° imbalanced. Jiang et al. 47) to the White-Kauffmann-Le Minor schemeShort-term signatures of evolutionary change in the Comparison of genome degradation in Paratyphi A and Typhi, human-restricted serovars of Complete genome sequence of a multiple drug resistant Comparative genomics of closely related salmonellaeVariable assortment of prophages provides a transferable repertoire of pathogenic determinants in Tissue-specific gene expression identifies a gene in the lysogenic phage Gifsy-1 that affects Complete genome sequence and comparative genomics of The dynamics and time scale of ongoing genomic erosion in symbiotic bacteriaGenome rearrangements, deletions, and amplifications in the natural population of Typing of typhoid bacilli with Vi bacteriophage; suggestions for its standardisationRibosomal RNA gene restriction patterns provide increased sensitivity for typing Bacteriophage typing of enteric pathogens and staphylococci and its use in epidemiologyrDNA fingerprinting as a tool in epidemiological analysis of Infectionskrankheiten und ihre Erreger, vol. 1. rrn arrangements of S. enterica serovars Typhimurium and Typhi. Replichore balance did not consistently improve over time but was random, depending on the strain isolated in a particular year, as clearly exemplified by strains isolated from carrier 4 (Rearrangements occur infrequently during standard culturing conditions, as demonstrated by Helm et al.