Comparison of strand-specific transcriptomes of enterohemorrhagic Escherichia coli O157:H7 EDL933 (EHEC) under eleven different environmental conditions
ABSTRACT: Multiple infection sources for enterohemorrhagic Escherichia coli O157:H7 are known, including food of animal origin and produce. The ecology of this pathogen outside its human host is largely unknown. One third of its annotated genes still are hypothetical. To identify genetic determinants expressed under environmental factors, we applied strand-specific RNA-sequencing of strain E. coli EDL933 under 11 different biotic and abiotic conditions: LB medium at pH4, pH7, pH9, or at 15°C; LB with nitrite or trimethoprim-sulfamethoxazole; LB-agar surface, M9 minimal medium, spinach leaf juice, surface of living radish sprouts, and cattle feces. Of 5379 annotated genes, only 144 are transcriptionally completely inactive under all conditions. Of 1,771 hypothetical genes, 1,672 exhibit significant transcriptional signals under at least one condition. The pathogenicity island LEE showed highest transcriptional activity in LB medium, minimal medium, and after treatment with antibiotics. Unique sets of genes, including many hypothetical genes, are highly up regulated on radish sprouts, cattle feces, or in the presence of antibiotics. For instance, azoR is biotechnologically important, but its environmental function has been elusive. This gene is highly active on radish sprouts. Further, we observed induction of the shiga-toxin carrying phages by antibiotics and confirmed active biofilm related genes on radish sprouts, in cattle feces, and on agar plates. Thus, environmental transcriptomics uncovers hitherto unknown gene functions and regulatory patterns of Escherichia coli O157:H7. Eleven different conditions were sequenced on the SOLiD system. Of two of the condtions, spinach medium and LB-nitrite, technical replicates were sequenced. Of LB medium and radish sprouts, biological replicates were sequenced on an Illumina MiSeq.
SUBMITTER: Steffen Schober Klaus NeuhausSvenja SimonDaniel KeimRichard B LandstorferSiegfried SchererRichard B. Landstorfer
Project description:Elucidating the role of gut microbiota in physiological and pathological processes has recently emerged as a key research aim in life sciences. In this respect, metaproteomics (the study of the whole protein complement of a microbial community) can provide a unique contribution by revealing which functions are actually being expressed by specific microbial taxa. However, its wide application to gut microbiota research has been hindered by challenges in data analysis, especially related to the choice of the proper sequence databases for protein identification. Here we present a systematic investigation of variables concerning database construction and annotation, and evaluate their impact on human and mouse gut metaproteomic results. We found that both publicly available and experimental metagenomic databases lead to the identification of unique peptide assortments, suggesting parallel database searches as a mean to gain more complete information. Taxonomic and functional results were revealed to be strongly database-dependent, especially when dealing with mouse samples. As a striking example, in mouse the Firmicutes/Bacteroidetes ratio varied up to 10-fold depending on the database used. Finally, we provide recommendations regarding metagenomic sequence processing aimed at maximizing gut metaproteome characterization, and contribute to identify an optimized pipeline for metaproteomic data analysis.
Project description:In this study, small RNAs were isolated from individual donations of eight forensically relevant biological fluids (blood, semen, vaginal fluid, menstrual blood, saliva, urine, feces, and perspiration) and subjected to next generation sequencing using the Illumina® Hi-Seq platform. Sequencing reads were aligned and annotated against miRbase release 21, resulting in a list of miRNAs and their relative expression levels for each sample analyzed. Body fluids with high bacterial loads (vaginal fluid, saliva, and feces) yielded relatively low annotated miRNA counts, likely due to oversaturation of small RNAs from the endogenous bacteria. Both body-fluid specific and potential normalization miRNAs were identified for further analysis as potential body fluid identification tools for each body fluid. 32 samples - 3-5 replicates of each human biological fluid: venous blood, urine, semen (normal and vasectomized), vaginal secretions, menstrual secretions, perspiration, feces, saliva
Project description:For phytophagous insects, the efficiency of utilization of hemicellulose and cellulose depends on the gut microbiota. Shifts in environmental and management conditions alter the presence and abundance of plant species which may induce adaptations in the diversity of gut microbiota. To test the adaptation of the microbiota to a shift from a natural diverse to a monocultural meadow with Dactylis glomerata the highly abundant grasshopper species, Chorthippus dorsatus, was taken from the wild and kept in captivity and were fed with Dactylis glomerata for five days. The feces were collected and analyzed by metaproteomics. After the diet shift from a diverse source to the single source, the microbiota composition stays relatively stable. The Bacilli as the group of highest abundance did not change on the functional level. In contrast, pronounced shifts of amino acid and carbohydrate metabolism in Clostridia and Proteobacteria were observed. Hence, the adaptation upon short-term change of food source in this grasshopper species is dominated by functional adaptations and not by shifts in the community structure of the microbiota. This suggests that the microbiota of grasshoppers is capable to cope also with the loss of diverse feeding plants at least for a shorter time period.
Project description:Methylated sulfur compounds, including dimethylsulfide (DMS), methylmercaptopropionic acid (MMPA) and methylsulfide (MeSH), are well-documented to play roles in global sulfur cycle and climate homeostasis, yet the molecular mechanisms of how they are metabolized by methanogens remain largely uncharacterized. Here, using high-throughtput sequencing of RNA (RNA-seq), we gained insight into how methanogens respond to methylated sulfur compounds at the transcriptional level. The mRNA from wild-type of Methanosarcina acetivorans C2A grown on methylated sulfur compounds were harvested, sequenced and mapped to the genome. Then, we compared RNA-seq profiles to that grown on MeOH in search of unque genes.
Project description:Gene regulation via transcription factors influences the metabolic, adaptive and pathogenic capabilities of the organism. We report the transcriptomes of the mutants of six major P. aeruginosa PA14 trancription factors - RhlR, LasR, Anr, GacA, FleQ and CbrB. The P. aeruginosa PA14 transposon mutants were analyzed by RNA-seq. All samples were cultivated in LB medium until reaching an OD600 of 2.0. For each biological replicate, three cultures were pooled for RNA extraction, library preparation and sequencing.
Project description:5' RNASeq of mRNA from Shewanella amazonensis SB2B grown aerobically in Luria-Bertani broth (LB) and defined lactate minimal medium 5'-end mRNA profiles of mid-log phase bacterial cells growing in LB or lactate medium were generated by next-generation sequencing.
Project description:5' RNASeq of mRNA from S. oneidensis MR-1 grown aerobically in Luria-Bertani broth (LB) and defined lactate minimal medium 5'-end mRNA profiles of mid-log phase bacterial cells growing in LB or lactate medium were generated by next-generation sequencing.
Project description:5' RNASeq of mRNA from Shewanella sp ANA-3 grown aerobically in Luria-Bertani broth (LB) and defined lactate minimal medium 5'-end mRNA profiles of mid-log phase bacterial cells growing in LB or lactate medium were generated by next-generation sequencing.
Project description:5' RNASeq of mRNA from Shewanella sp MR-7 grown aerobically in Luria-Bertani broth (LB) and defined lactate minimal medium 5'-end mRNA profiles of mid-log phase bacterial cells growing in LB or lactate medium were generated by next-generation sequencing.