Science 1994, 266:1380–1383.PubMedCrossRef 45. Fiala KI, Sokal RR: Factors determining the accuracy of cladogram estimation-evaluation using computer-simulation. Evolution 1985, 39:609–622.CrossRef 46. Kingman JFC: The Coalescent. Stochastic Processes and their applications 1982, 13:235–248.CrossRef Authors’ contributions JC conceived and designed the study, performed and interpreted

the phylogenetic and statistical MEK162 in vitro analyses, participated in the collection of the sequence data and animal assays, and drafted the manuscript. QC performed the PCR amplification and participated in the collection of the sequence data. LJ participated in evaluation of the results and in revision of the manuscript. CC and FB participated in the PCR amplification, biochemical tests and animal assays. JW and FM participated in the analysis of sequence data. selleck inhibitor WF supervised the project, participated in the design of the study and data interpretation,

and helped draft the manuscript. All authors read and approved the final manuscript.”
“Background Globally, Salmonella enterica subsp. enterica is one of the leading food-borne pathogens. For example in 2006 in the United States, Salmonella enterica subsp. enterica caused 45.808 registered CP673451 research buy cases of salmonellosis, corresponding to an incidence of 15 cases/100,000 inhabitants [1]. Furthermore the actual number of infections is estimated to be 38 times higher [2]. In Denmark, there were 1658 registered cases of salmonellosis (incidence of 30 cases/100,000 inhabitants) in 2006 [3]. Salmonella serotype Typhimurium, denoted S. Typhimurium, accounted for 17% of the salmonellosis cases in the USA and 25% of the Danish cases [1, 3]. The outcome of human infection ranges from mild self-limiting diarrhoea to severe diarrhoea that requires hospitalization. In rare cases, often among immunocompromised patients, salmonellosis can be fatal. Several factors in both the host and the bacteria influence the outcome of an infection. Clearly an important aspect of human infection is the immune state of the patient. It has been shown that immunocompromised Loperamide patients are more prone to develop a severe infection

[4]. Another important aspect of human infection is the intestinal microbiota of the host. Ingestion of antibiotics is known to affect the intestinal microbiota leaving the host more prone to infection and disease caused by S. Typhimurium [5]. Significant bacterial factors for the outcome of infection are encoded by a wide range of genetic elements, including plasmids, prophages and Salmonella Pathogenicity Islands (SPIs). A total of 14 SPIs have been described so far [6]. SPI-1 encodes type 3 secretion system 1 (T3SS-1) that causes secretion and translocation of a range of bacterial proteins to the host cell. SPI-2 encodes T3SS-2 that allows intracellular survival and replication [7]. Different S. Typhimurium strains share more than 99% genomic content [8]. The detected variation within S.