Project description:Salmonella remains an important enteric pathogen of poultry, primarily due to concerns regarding food-borne illness in humans consuming contaminated poultry products. Specific probiotic cultures are efficacious as a treatment for neonatal poultry to prevent enteric infections (competitive exclusion) due to the exquisite susceptibility of young chicks to pathogens in the hatchery and brooding environment. The objective of this experiment was to analyze transcriptional profiles in the ceca of neonatal chicks using the Arizona Gallus gallus 20.7K Oligo Array v1.0, following treatment with a probiotic culture derived from poultry with and without Salmonella enterica subsp. Enteritidis (SE) challenge. Chicks were obtained from a commercial hatchery, and challenged with SE upon arrival at the laboratory. One hour post-challenge, chicks were treated with a probiotic culture (FM-B11). Treatment groups included: Control (no challenge or treatment, vehicle only), SE (challenged only), B11 (treated only) and SE+B11 (challenged and treated). Samples were obtained at 12h and 24h post-treatment. We observed that administration of a Lactobacillus-based probiotic culture to chicks following challenge with SE reduced SE colonization of the cecae and resulted in differential expression of genes in the cecae. Among all four treatment groups, 309 genes were differentially expressed (p<0.05) at 12h, and 352 genes were differentially expressed (p<0.05) at 24h. Keywords: disease state analysis Eight experimental groups with 4 replicates each were analyzed. A reference RNA design was used for this microarray. Equal amounts of amplified RNA (aRNA) from all samples were pooled and labelled with the Alexa 647 to create the reference pool. Each individual sample was labelled with Alexa 555. Each slide was hybridized with both the reference pool and one sample.
Project description:Salmonella remains an important enteric pathogen of poultry, primarily due to concerns regarding food-borne illness in humans consuming contaminated poultry products. Specific probiotic cultures are efficacious as a treatment for neonatal poultry to prevent enteric infections (competitive exclusion) due to the exquisite susceptibility of young chicks to pathogens in the hatchery and brooding environment. The objective of this experiment was to analyze transcriptional profiles in the ceca of neonatal chicks using the Arizona Gallus gallus 20.7K Oligo Array v1.0, following treatment with a probiotic culture derived from poultry with and without Salmonella enterica subsp. Enteritidis (SE) challenge. Chicks were obtained from a commercial hatchery, and challenged with SE upon arrival at the laboratory. One hour post-challenge, chicks were treated with a probiotic culture (FM-B11). Treatment groups included: Control (no challenge or treatment, vehicle only), SE (challenged only), B11 (treated only) and SE+B11 (challenged and treated). Samples were obtained at 12h and 24h post-treatment. We observed that administration of a Lactobacillus-based probiotic culture to chicks following challenge with SE reduced SE colonization of the cecae and resulted in differential expression of genes in the cecae. Among all four treatment groups, 309 genes were differentially expressed (p<0.05) at 12h, and 352 genes were differentially expressed (p<0.05) at 24h. Keywords: disease state analysis
Project description:Disease outbreaks due to the consumption of legume seedlings contaminated with human enteric bacterial pathogens like Escherichia coli O157:H7 and Salmonella enterica are reported every year. We found surface and internal colonization of Medicago truncatula by Salmonella enterica and Escherichia coli O157:H7 even with inoculum levels as low as two bacteria per plant. Expression analyses using microarray revealed that some Medicago truncatula genes were regulated in a similar manner in response to both of these enteric pathogens. Medicago truncatula roots were inoculated with low inoculum levels of two enteric bacteria per plant (E. coli O157:H7 and Salmonella). 10 days post inoculated plants were used for RNA extraction and hybridization on Affymetrix microarrays.
Project description:To characterize the differentially expressed genes between pathogenic avian E. coli and human E. coli ATCC 25922, Abstract Escherichia coli (E. coli) is a harmless common bacterium of poultry intestine, but with a wide range of genomic flexibility, is also causative agent of many poultry diseases collectively called colibacillosis that is blamed for high economic loss in poultry sector worldwide. Numerous studies have been conducted to check the prevalence of pathogenic E. coli in poultry and poultry products, however limited data are available regarding their resistance and virulence associated genes expression profile. This study examined the pathogenomic content of poultry E. coli by antibiotic susceptibility, biofilm formation and adhesion, invasion and intracellular survivability assays in Caco-2 and Raw 264.7 cell lines along with the determination of median lethal dose in two-day old chickens. A clinical pathogenic multidrug resistant (MDR) isolate, E. coli 381, isolated from broilers was found to be highly virulent in cell culture and in chicken model. Transcriptome analysis has been skewed towards bacterial pathogens because of the prioritization of poultry diseases. Comparative gene expression profile of MDR E. coli 381 and the reference human strain E. coli ATCC 25922 was done using Illumina HiSeq2500 transcriptome and results were verified by RT-qPCR analyses. A number of resistant encoding genes including multidrug transporters, multidrug resistance proteins, porins and autotransporters were identified. We also noticed overexpression of very important virulent genes (fimA, fimC, fimH and fimI) encoding the type-1 fimbrial proteins, curli fimbriae genes , invasin genes, toxin-encoding genes and biofilm forming regulatory genes . In addition, many types of stress and metal homeostasis controlling genes were among up-regulated genes in E. coli 381 as compared to reference strain. GO and KEGG pathway analysis results revealed that genes controlling secondary metabolism, drug transport, adhesion and invasion proteins, and mobile genetic elements were over-expressed in E. coli 381. Several genes involved in cellular and metabolic processes such as carbohydrate metabolism were responsible for stress tolerance. Seminal description of the transcriptomic results and other unique features of E. coli 381 confirmed that it is highly virulent and MDR strain of poultry origin. This comparative study provides new avenues for further work on molecular mechanisms to prevent resistance development in bacteria and to ensure public health.
2017-09-26 | GSE94978 | GEO
Project description:Enteric Pathogens Genomic Surveillance in Bangladesh
Project description:Disease outbreaks due to the consumption of legume seedlings contaminated with human enteric bacterial pathogens like Escherichia coli O157:H7 and Salmonella enterica are reported every year. We found surface and internal colonization of Medicago truncatula by Salmonella enterica and Escherichia coli O157:H7 even with inoculum levels as low as two bacteria per plant. Expression analyses using microarray revealed that some Medicago truncatula genes were regulated in a similar manner in response to both of these enteric pathogens.