Project description:Comparison between the multi-drug resistance Salmonella enteric serotype Newport strains from the US and the pan-susceptible strains from the UK
Project description:Screen for differences in gene expression between a parental Salmonella enterica serovar Enteritidis strain (ATCC4931) and an adapted strain with increased resistance to the widely used antimicrobial sanitizer dodecyltrimethylammonium chloride (DTAC) Time course of comparative gene expression changes between log phase parental and adapted Enteritidis strains after 0, 10, 30 and 150 min of exposure to 50% of the respective MIC of DTAC.
Project description:Screen for differences in gene expression between a parental Salmonella enterica serovar Enteritidis strain (ATCC4931) and an adapted strain with increased resistance to the widely used antimicrobial sanitizer dodecyltrimethylammonium chloride (DTAC)
Project description:Microarray based CGH was conducted over a group of 29 strains of S. Enteritidis spanning different epidemiological periods in Uruguay, plus 6 other S. Enteritidis strains isolated from distant geographical regions. We also included 9 Salmonella enterica strains of other serovars isolated in Uruguay. A S. Enteritidis dispensable genome of 233 chromosomal genes and high extent of variation in virulence plasmid was found. Strains isolated before the epidemic show the highest genomic differences as compared with the PT4 reference strain. Comparison with the gene content of other serovars demonstrate extensive horizontal gene transfer between circulating strains beyond serovar definition. Our results show that the epidemic of S Enteritidis in Uruguay was produced by the introduction of strains closely related to PT4, and corroborate the extensive genetic homogeneity among S. Enteritidis isolates worldwide. Phage SE14 emerges as the only specific region for S. Enteritidis. Genetic differences detected in pre-epidemic strains, mainly associated with the absence of phage SE20, suggest that genetic features encoded in this phage may be related to particular epidemiological behavior.
Project description:Salmonella Enteritidis is the major food-borne pathogen primarily causing human infection through contaminated chicken meat and eggs. We recently demonstrated that S. Enteritidis strains from poultry differ in their ability to invade human intestinal cells and cause disease in orally challenged mice. Here we hypothesized that the differential pathogenicity of S. Enteritidis strains is due to the differential fitness in the adverse environments that may be encountered during infection in the host. The response of a panel of six S. Enteritidis strains to acid stress, oxidative stress, survival in egg albumen and the ability to cause infection in chickens were analyzed. This analysis allowed classification of strains into two categories: stress- sensitive and stress- resistant, with the former showing significantly (P<0.05) reduced survival in acidic (gastric phase of infection) and oxidative (intestinal and systemic phase of infection) stress. Stress-sensitive strains also showed impaired intestinal colonization and systemic dissemination in orally inoculated chickens and failed to survive/grow in egg albumen. Comparative genomic hybridization microarray analysis revealed no differences at the discriminatory level of the whole gene content between stress-sensitive and stress-resistant strains. However, sequencing of rpoS, a stress-regulatory gene, revealed that one of the three stress-sensitive strains carried an insertion mutation in the rpoS resulting in truncation of σS. Finding that one of the stress-sensitive strains carried an easily identifiable small polymorphism within a stress-response gene suggests that the other strains may also have small polymorphisms elsewhere in the genome, which likely impact regulation of stress or virulence associated genes in some manner.
Project description:Whole genome sequencing of SYBARIS Aspergillus spp. known to be multi-drug resistant and difficult to treat. Aim of this experiment is to investigate the genetic basis of susceptibility to disease and elucidate molecular mechanisms of drug resistance in these strains.
Project description:Tuberculosis (TB) is one of the deadliest infectious disorders in the world. To effectively TB manage, an essential step is to gain insight into the lineage of Mycobacterium tuberculosis (MTB) strains and the distribution of drug resistance. Although the Campania region is declared a cluster area for the infection, to contribute to the effort to understand TB evolution and transmission, still poorly known, we have generated a dataset of 159 genomes of MTB strains, from Campania region collected during 2018-2021, obtained from the analysis of whole genome sequence data. The results show that the most frequent MTB lineage is the 4 according for 129 strains (81.11%). Regarding drug resistance, 139 strains (87.4%) were classified as multi susceptible, while the remaining 20 (12.58%) showed drug resistance. Among the drug-resistance strains, 8 were isoniazid-resistant MTB (HR-MTB), 7 were resistant only to one antibiotic (3 were resistant only to ethambutol and 3 isolate to streptomycin while one isolate showed resistance to fluoroquinolones), 4 multidrug-resistant MTB, while only one was classified as pre-extensively drug-resistant MTB (pre-XDR). This dataset expands the existing available knowledge on drug resistance and evolution of MTB, contributing to further TB-related genomics studies to improve the management of TB infection.
Project description:In the two F8 advanced crosses of broiler by Leghorn and broiler by Fayoumi, birds at day 1 were challenged with Salmonella enteritidis (SE). Spleen were collected at day 7 and 8. SE bacterial load in spleen were measured. Based on the bacterial load, birds were divided into high and low SE load groups. Keywords: Salmonella enteritidis challenge
Project description:The purpose of this experiment was to identify intestinal epithelial responses to various strains of Salmonella enterica. Human intestinal organoids were infected with three serovars of Salmonella; Typhimurium, Enteritidis and Typhi, as well as type 3 secretion system -1 and -2 mutants in Typhimurium in order to identify host responses that were similar and unique to each serovar, and responses that were dependent on these secretion systems.
