Project description:During initial colonization of the airways, MAH form microaggregates composed of 3-20 bacteria on human respiratory epithelial cells, which provides an environment for phenotypic changes leading to efficient mucosal invasion. DNA microarray was employed to identify genes associated with the microaggregate phenotype. Bacteria were incubated with Hep-2 epithelial cells for 24 hrs to form microaggregates or incubated in tissue culture media alone as the control (planktonic bacteria). Bacterial RNA was isolated, purified using MicrobeEnrich, and amplified using Abmbion's Bacterial MessageAMP kit. RNA was hybridized to Affymetrix custom made mycobacterium avium 104 microarrays
Project description:Bacteria that live in the acidic environment face number of growth-related challenges from the intracellular pH changes. In order to survive under acidic environment, Lactic acid bacteria must employ multiple genes and proteins to regulate the relative pathways.
Project description:Bacteria that live in the acidic environment face number of growth-related challenges from the intracellular pH changes. In order to survive under acidic environment, Lactic acid bacteria must employ multiple genes and proteins to regulate the relative pathways.
Project description:Individuals with cystic fibrosis are susceptible to co-infection by Aspergillus fumigatus and Pseudomonas aeruginosa, however P. aeruginosa eventually predominates as the primary pathogen. Several factors are likely to facilitate P. aeruginosa colonization in the airways, including alterations to the microbial environment. In this study, significant growth proliferation was observed in P. aeruginosa when the bacteria were exposed to culture filtrates produced by A. fumigatus in a nitrate-rich, nutrient-poor liquid broth, Czapek-Dox. Proteomic analysis of the A. fumigatus culture filtrate identified a significant number of environment-altering proteases and peptidases, which may contribute to the growth promoting effect observed when P. aeruginosa is exposed to this culture filtrate. These findings offer insights into the determinants that contribute to P. aeruginosa proliferation in the presence of A. fumigatus.
Project description:Transcriptional profiling of Caco-2 cells comparing Caco-2 monolayers cultured in a custom built co-culture chamber, either inside a 5% CO₂ incubator (conventional cell culture environment) or an anaerobic workstation (apical anaerobic environment) for 12 hours.
Project description:Cronobacter sakazakii is well-known for its desiccation tolerance in the powdered infant formula (PIF) food production environment and the bacterium has been linked with high fatality rates in neonates who consume contaminated product. In this study, using deep-level RNA-sequencing, differentially expressed genes were studied in C. sakazakii ATCCTM29544 grown in simulated low-moisture environment designed to mimic the PIF production environment. Desiccation of bacteria was carried out on stainless steel coupons from which total RNA was subsequently recovered and sequenced. During 4 h of desiccation from the early stationary phase (ESP) grown culture, an approximately 3 log10 reduction was recorded for C. sakazakii viable cell count, with the largest change in viable cells occurring between desiccation hour 1 and 2 during which the culture medium was completely dried. Transcriptomic data obtained after 4 h of desiccation highlighted several highly-up regulated osmotolerance-related genes which were associated with the secondary response mechanism. These actively expressed genes mainly modulate pathways that synthetize glycine betaine and trehalose as well as the transport of these two and other compatible solutes. Understanding the activities of these genes and pathways will assist the development of technologies that mitigate the survival of C. sakazakii in the PIF production process.
Project description:Nitrate-reducing iron(II)-oxidizing (NDFO) bacteria are widespread in the environment contribute to nitrate removal and influence the fate of the greenhouse gases nitrous oxide and carbon dioxide. The autotrophic growth of nitrate-reducing iron(II)-oxidizing bacteria is rarely investigated and poorly understood. The most prominent model system for this type of studies is enrichment culture KS, which originates from a freshwater sediment in Bremen, Germany. A second NDFO culture, culture BP, was obtained with a sample taken in 2015 at the same pond and cultured in a similar way. To gain insights in the metabolism of nitrate reduction coupled to iron(II) oxidation under in the absence of organic carbon and oxygen limited conditions, we performed metagenomic, metatranscriptomic and metaproteomic analyses of culture BP. Raw sequencing data of 16S rRNA amplicon sequencing (V4 region with Illumina and near full-length with PacBio), shotgun metagenomics, metagenome assembly, raw sequencing data of shotgun metatranscriptomes (2 conditions, triplicates) can be found at SRA in https://www.ncbi.nlm.nih.gov/bioproject/PRJNA693457. This dataset contains proteomics data for 2 conditions in triplicates. Samples R23, R24, and R25 are grown in autotrophic conditions, samples R26, R27, and R28 in heterotrophic conditions.