Salmonella enterica: survival, colonization, and virulence differences among serovars.
Ontology highlight
ABSTRACT:
SUBMITTER: Andino A
PROVIDER: S-EPMC4310208 | biostudies-other | 2015
REPOSITORIES: biostudies-other
Similar Datasets
Project description:This experiment set includes 64 arrays representing 26 serovars and strains of Salmonella spp. including many representatives of subspecies I, Arizona from subsp. IIIa, and S. bongori from subsp. V. The genomic DNA from all strains were labeled with Cy5 and hybridized against an equal amount (1.5 ug) of S. typhimurium SL1344 reference genomic DNA that was labeled with Cy3, all on an S. typhimurium SL1344 spotted DNA microarray. Most of the arrays are present in triplicate to account for variability in probe generation, hybridization, and slide quality. Several are represented in duplicate, and a few without any replicates. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
2005-11-04 | GSE3564 | GEO
Project description:The serovars of Salmonella enterica display dramatic differences in pathogenesis and host preferences. We developed a process (patent pending) for grouping Salmonella isolates and serovars by their public health risk. We collated a curated set of 12,337 S. enterica isolate genomes from human, beef, and bovine sources in the US. After annotating a virulence gene catalog for each isolate, we used unsupervised random forest methods to estimate the proximity (similarity) between isolates based upon the genomic presentation of putative virulence traits We then grouped isolates (virulence clusters) using hierarchical clustering (Ward's method), used non-parametric bootstrapping to assess cluster stability, and externally validated the clusters against epidemiological virulence measures from FoodNet, the National Outbreak Reporting System (NORS), and US federal sampling of beef products. We identified five stable virulence clusters of S. enterica serovars. Cluster 1 (higher virulence) serovars yielded an annual incidence rate of domestically acquired sporadic cases roughly one and a half times higher than the other four clusters combined (Clusters 2-5, lower virulence). Compared to other clusters, cluster 1 also had a higher proportion of infections leading to hospitalization and was implicated in more foodborne and beef-associated outbreaks, despite being isolated at a similar frequency from beef products as other clusters. We also identified subpopulations within 11 serovars. Remarkably, we found S. Infantis and S. Typhimurium subpopulations that significantly differed in genome length and clinical case presentation. Further, we found that the presence of the pESI plasmid accounted for the genome length differences between the S. Infantis subpopulations. Our results show that S. enterica strains associated with highest incidence of human infections share a common virulence repertoire. This work could be updated regularly and used in combination with foodborne surveillance information to prioritize serovars of public health concern.
| S-EPMC10697515 | biostudies-literature
Project description:The methylation of DNA bases plays an important role in numerous biological processes including development, gene expression, and DNA replication. Salmonella is an important foodborne pathogen, and methylation in Salmonella is implicated in virulence. Using single molecule real-time (SMRT) DNA-sequencing, we sequenced and assembled the complete genomes of eleven Salmonella enterica isolates from nine different serovars, and analysed the whole-genome methylation patterns of each genome. We describe 16 distinct N6-methyladenine (m6A) methylated motifs, one N4-methylcytosine (m4C) motif, and one combined m6A-m4C motif. Eight of these motifs are novel, i.e., they have not been previously described. We also identified the methyltransferases (MTases) associated with 13 of the motifs. Some motifs are conserved across all Salmonella serovars tested, while others were found only in a subset of serovars. Eight of the nine serovars contained a unique methylated motif that was not found in any other serovar (most of these motifs were part of Type I restriction modification systems), indicating the high diversity of methylation patterns present in Salmonella.
| S-EPMC4393132 | biostudies-literature
Project description:We describe the development of a spotted array for the delineation of the most common 14 disease-causing Salmonella serovars in the United States. Our array consists of 414 70 mers targeting core genes of Salmonella enterica, subspecies I specific genes, fimbrial genes, pathogenicity islands, Gifsy elements and other variable genes. Using this array we were able to identify a unique gene presence/absence profile for each of the targeted serovar which was used as the serovar differentiating criteria. Based on this profile, we developed a Matlab programme that compares the profile of an unknown sample to all 14 reference serovar profiles and give out the closest serovar match. Since we have included probes targeting most of the virulence genes and variable genes in Salmonella, in addition to using for serovar detection this array could also be used for studying the virulence gene content and also for evaluating the genetic relation between different isolates of Salmonella.
| S-EPMC2766089 | biostudies-literature
Project description:BackgroundThe impact of S. enterica colonization in cattle is highly variable and often serovar-dependent. The aim of this study was to compare the global transcriptomes of highly pathogenic bovine-adapted S. enterica serovar Dublin and the less pathogenic, bovine-adapted, serovar Cerro during interactions with bovine epithelial cells, to identify genes that impact serovar-related outcomes of S. enterica infections in dairy animals.ResultBovine epithelial cells were infected with S. enterica strains from serovars Dublin and Cerro, and the bacterial RNA was extracted and sequenced. The total number of paired-end reads uniquely mapped to non-rRNA and non-tRNA genes in the reference genomes ranged between 12.1 M (Million) and 23.4 M (median: 15.7 M). In total, 360 differentially expressed genes (DEGs) were identified with at least two-fold differences in the transcript abundances between S. Dublin and S. Cerro (false discovery rate ≤ 5%). The highest number of DEGs (17.5%, 63 of 360 genes) between the two serovars were located on the genomic regions potentially associated with Salmonella Pathogenicity Islands (SPIs). DEGs potentially located in the SPI-regions that were upregulated (≥ 2-fold) in the S. Dublin compared with S. Cerro included: 37 SPI-1 genes encoding mostly Type 3 Secretion System (T3SS) apparatus and effectors; all of the six SPI-4 genes encoding type I secretion apparatus (siiABCDEF); T3SS effectors and chaperone (sopB, pipB, and sigE) located in SPI-5; type VI secretion system associated protein coding genes (sciJKNOR) located in SPI-6; and T3SS effector sopF in SPI-11. Additional major functional categories of DEGs included transcription regulators (n = 25), amino acid transport and metabolism (n = 20), carbohydrate transport and metabolism (n = 20), energy production and metabolism (n = 19), cell membrane biogenesis (n = 18), and coenzyme transport and metabolism (n = 15). DEGs were further mapped to the metabolic pathways listed in the KEGG database; most genes of the fatty acid β-oxidation pathway were upregulated/uniquely present in the S. Dublin strains compared with the S. Cerro strains.ConclusionsThis study identified S. enterica genes that may be responsible for symptomatic or asymptomatic infection and colonization of two bovine-adapted serovars in cattle.
| S-EPMC9270791 | biostudies-literature
Project description:The aim of this study was to estimate virulence potential of Salmonella enterica strains colonizing the gut of free-living sand lizards (Lacerta agilis L.). The strains belonged to three Salmonella serovars: Abony, Schleissheim, and Telhashomer. Adhesion and invasion abilities of the strains were determined in quantitative assays using the gentamicin protection method. Induction of apoptosis was assessed using HeLa cell monolayers. PCR assays were used for detection of 26 virulence genes localised within mobile elements: pathogenicity islands, virulence plasmids, and prophage sequences. In vitro studies revealed that all strains had adhesion and invasion abilities to human epithelial cells. The isolates were cytotoxic and induced apoptosis of the cells. The serovars differed in the number of virulence-associated genes: up to 18 genes were present in Salmonella Schleissheim, 17 in Salmonella Abony, whereas as few as six genes were found in Salmonella Telhashomer. Generally, Salmonella Abony and Salmonella Schleissheim did not differ much in gene content connected with the presence SPI-1 to -5. All of the strains lacked genes localised within bacteriophages and plasmids. The presence of virulence-associated genes and in vitro pathogenicity assays suggest that Salmonella sp. strains originating from autochthonous, free-living lizards can potentially infect and cause disease in humans.
| S-EPMC6153992 | biostudies-literature
Project description:RNA extracted from representative isolates of each serovar grown to late exponential phase in Luria-Bertani broth showed that transcript abundances of core genes were significantly higher (p < 0.05) than those of accessory genes for all three serovars. Inter-serovar comparisons demonstrated higher transcript abundances for genes related to vitamin B12 biosynthesis, and ethanolamine and 1,2-propanediol utilization in S. Cerro compared to Javiana and Typhimurium, while genes in Salmonella Pathogenicity Island (SPI) 1 had significantly higher transcript abundances in S. Javiana and S. Typhimurium.
2020-05-21 | GSE150943 | GEO
Project description:Virulent and multi drug resistant (MDR) Salmonellaenterica is a foremost cause of foodborne diseases and had serious public health concern globally. The present study was undertaken to identify the pathogenicity and antimicrobial resistance (AMR) profiles of Salmonellaenterica serovars recovered from chicken at wet markets in Dhaka, Bangladesh. A total of 870 cecal contents of broiler, sonali, and native chickens were collected from 29 wet markets. The overall prevalence of S. Typhimurium, S. Enteritidis, and untyped Salmonella spp., were found to be 3.67%, 0.57%, and 1.95% respectively. All isolates were screened by polymerase chain reaction (PCR) for eight virulence genes, namely invA, agfA, IpfA, hilA, sivH, sefA, sopE, and spvC. S. Enteritidis isolates carried all virulence genes whilst S. Typhimurium isolates carried six virulence genes except sefA and spvC. A diverse phenotypic and genotypic AMR pattern was found. Harmonic descending trends of resistance patterns were observed among the broiler, sonali, and native chickens. Interestingly, virulent and MDR Salmonella enterica serovars were found in native chicken, although antimicrobials were not used in their production cycle. The research findings anticipate that virulent and MDR Salmonella enterica are roaming in the wet markets which can easily anchor to the vendor, consumers, and in the food chain.
| S-EPMC8145576 | biostudies-literature
Project description:This experiment set includes 64 arrays representing 26 serovars and strains of Salmonella spp. including many representatives of subspecies I, Arizona from subsp. IIIa, and S. bongori from subsp. V. The genomic DNA from all strains were labeled with Cy5 and hybridized against an equal amount (1.5 ug) of S. typhimurium SL1344 reference genomic DNA that was labeled with Cy3, all on an S. typhimurium SL1344 spotted DNA microarray. Most of the arrays are present in triplicate to account for variability in probe generation, hybridization, and slide quality. Several are represented in duplicate, and a few without any replicates. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Computed
2005-11-03 | E-GEOD-3564 | biostudies-arrayexpress
Project description:BackgroundThis study aimed to survey the prevalence, antimicrobial resistance, and virulence-associated genes of Salmonella enterica recovered from broiler chickens and retail shops at El-Sharkia Province in Egypt. Salmonella virulence factors were determined using the polymerase chain reaction assays targeting the invA, csgD, hilC, bcfC, stn, avrA, mgtC, ompF, sopE1 and pefA genes.ResultsOne hundred tweenty out of 420- samples from broiler chickens' cloacal swabs, farm environmental samples, and freshly dressed whole chicken carcasses were positive Salmonella species. The isolates were serotyped as S. Enteritidis as the most dominant serotypes. Interestingly, none of the isolates were resistant to imipenem. The multidrug resistance was determined in 76.7% of the isolates with multidrug antibiotic resistance index of 0.2-0.6. Eight virulence genes (invA, csgD, hilC, stn, bcfC, mgtC, avrA, and ompf) were characterized among 120 S. enterica isolates with variable frequencies, while sopE1and pefA genes that were completely absent in all isolates. Based on the combination of presence and absence of virulence genes, the most common genetic profile (P7, 30%) was invA and csgD genes.ConclusionS. Enteritidis and S. Typhimurium were the most common identified serotypes in the examined sources. Circulation of such strains in broiler farms required introducing special biosecurity and biocontrol measures for control of Salmonella. Such measures might limit the adverse effects of antibiotics and ensure the safety of the environment and animal-derived food.
| S-EPMC6486964 | biostudies-literature