Project description:Freshwater environments such as rivers receive effluent discharges from wastewater treatment plants, representing a potential hotspot for antibiotic resistance genes (ARGs). These effluents also contain low levels of different antimicrobials including biocides and antibiotics such as sulfonamides that can be frequently detected in rivers. The impact of such exposure on ARG prevalence and microbial diversity of riverine environment is unknown, so the aim of this study was to investigate the release of a sub-lethal concentration (<4 g L-1) of the sulfonamide compound sulfamethoxazole (SMX) on the river bacterial microbiome using a microflume system. This system was a semi-natural in-vitro microflume using river water (30 L) and sediment, with circulation to mimic river flow. A combination of ‘omics’ approaches were conducted to study the impact of SMX exposure on the microbiomes within the microflumes. Metaproteomics did not show differences in ARGs expression with SMX exposure in water.
Project description:In this study, we investigated the transcriptomic response of Streptococcus pneumoniae D39 to sialic acid (N-acetylneuraminic acid: Neu5Ac). Transcriptome comparison of the D39 wild-type grown in M17 medium with and without sialic acid revealed the elevated expression of various genes and operons including the nan gene cluster (nan operon-I and nanA gene). Our microarray analysis and promoter-lacZ fusion studies showed that the transcriptional regulator NanR acts as a transcriptional activator of nan operon-I and the nanA gene in the presence of sialic acid. The putative regulatory site of NanR in the promoter region of nan operon-I is predicted and confirmed by promoter truncation experiments. Furthermore, the role of CcpA in the regulation of the nan gene cluster is demonstrated through microarray analysis and promoter-lacZ fusion studies, suggesting that in the presence of sialic acid and glucose, CcpA represses the expression of nan operon-I while the expression of the nanA gene is CcpA-independent. This SuperSeries is composed of the SubSeries listed below.
Project description:We have developed a 60-mer oligonucleotide multibacterial microarray for detection and expression profiling of biodegradative genes and bacterial diversity (16S rRNA gene) in different habitats contaminated with varieties of hazardous chemicals. The genes selected were involved in biodegradation and biotransformation of various groups of compounds viz. nitroaromatic compounds (148 genes), chloroaromatic compounds (75 genes), monoaromatic compounds (373 genes), polyaromatic hydrocarbons (174 genes), pesticides/ herbicides (34 genes), alkanes/aliphatics (185 genes) and heavy metals (68 genes), which covered a total number of 133 chemicals. The efficiency (specificity, detection sensitivity) of the developed array was evaluated using the labeled genomic DNA of pure bacterial strains, Escherichia coli DH5α and Sphingomonas sp. strain NM-05 (involved in the biodegradation of γ-hexachlorohexane isolated from IPL, Lucknow) at different concentrations of 300ng, 500ng, 800ng, 1000ng and 1250ng. The specificity of the developed array was further validated using mixed cultures containing three strains (Sphingomonas sp. strain NM-05, Rhodococcus sp. strain RHA1 and Bordetella sp. strain IITR-02) involved in biodegradation of γ-hexachlorohexane, biphenyl and chlorobenzenes respectively. The mixed culture also contained non-target/non-degrader strains (E. coli DHα, E.coli BL21 and E.coli K12 NCTC50192). The developed array was applied for profiling using the total soil DNA in five contaminated habitats of north India, viz. chloroaromatic chemicals contaminated site (India Pesticide Limited, Chinhat, Lucknow), a river sediments (Gomti river sediment, Lucknow), heavy metal industry dump site (Jajmau industrial area Kanpur), a effluent treatment plant (CETP along Ganges river near Kanpur), and an oil refinery (Mathura oil refinery). Hybridization of 16S rRNA probes revealed the presence of bacteria similar to well characterized genera involved in biodegradation of pollutants. Genes involved in complete degradation pathways for hexachlorocyclohexane (lin), 1,2,4-trichlorobenzene (tcb), naphthalene (nah), phenol (mph), biphenyl (bph), benzene (ben), toluene (tbm), xylene (xyl), phthalate (pht), Salicylate (sal) and resistance to mercury (mer) were detected with highest intensity. The most abundant genes belonged to hydroxylases, monooxygenases and dehydrogenases which were present in all the five samples. Many compound specific genes which initiate the degradation pathway were also detected. Thus, the array developed and validated here may be useful in assessing the biodegradative potential and composition of environmentally useful bacteria in hazardous ecosystems.
Project description:EKLF/Klf1 is a Zinc-finger transcription activator essential for erythroid lineage commitment and terminal differentiation. Using ChIP-Seq, we investigate EKLF DNA binding and transcription activation mechanisms during mouse embryonic erythropoiesis. Our study focuses on global EKLF binding dynamics during embryonic erythropoiesis in primary WT and Nan/+ mouse fetal liver, and its correlation with chromatin accessibility, CBP occupancy, histone acetylation, and finally its effect on RNA Polymerase II pausing and elongation. Our goal is to elucidate the mechanisms of transcription activation by EKLF/Klf1 during embryonic erythropoiesis in vivo and in the context of RNA pol II pause-release control. Additionally, we aim to understand the unusually severe effects of conservative E to D change in Nan-EKLF and the molecular mechanisms leading to dominant anemia through global gene dysregulation.
Project description:Supporting microarray data for manuscript entitled "OSTEOPONTIN AND PAI-1 EXPRESSION IN MALIGNANT HYPERTENSION: SUPPRESSION BY p38 MAPK INHIBITORS" submitted to the HYPERTENSION journal. Experiment Overall Design: Male spontaneously hypertensive stroke-prone rats (SHR-SP) were obtained from Charles River (Raleigh, NC). At 11 weeks of age, the SHR-SP were randomized into 2 groups, and fed either powdered chow diet (Purina 5001) with water ad lib; or a high-salt/high-fat diet consisting of 1% NaCl in the drinking water and 24.5% fat in the chow (from Harlan TekLad, Madison, Wisconsin). 6 replicate animals per diet per time point.