Project description:We compared genetic profiles of planktonic stage to biofilm stage of deep sea bacterium Pseudoalteromonas sp. SM9913 and revealed genetic features during switch from planktonic to pellicle stage in Pseudoalteromonas sp. SM9913.
Project description:We compared genetic profiles of planktonic stage to biofilm stage of deep sea bacterium Pseudoalteromonas sp. SM9913 and revealed genetic features during switch from planktonic to pellicle stage in Pseudoalteromonas sp. SM9913. mRNA profiles of Pseudoalteromonas sp. SM9913 planktonic cells, initial pellicle cells and mature pellicle cells were generated by Illumina Hiseq2000.
Project description:One of the most distinct features of Pseudoalteromonas sp. SCSIO 11900 is its ability to form a very robust pellicle than most Pseudoalteromonas strains. Thus we want to identify the genes essential for the pellicle formation of SCSIO 11900. We compared transcriptom profiles of planktonic cells, initial pellicle and mature pellicle of coral Pseudoalteromonas sp. SCSIO 11900 and revealed that some unique genes from horizontal gene transfer is involved in the pellicle formation of SCSIO 11900.
Project description:Transcriptomic sequencing was performed to obtain the key functional genes involved in the adaptation of oxidative stress induced by hydrogen peroxide (H2O2) in the Arctic bacterium Pseudoalteromonas sp. A2. Exposure to 1 mmol/L H2O2 resulted in large alterations of the transcriptome profile, including significant upregulation of 109 genes and significant downregulation of 174 genes. Functional classification of differentially expressed genes revealed that most of genes affiliated with biological adhesion, negative regulation of biological process, enzyme regulator activity, protein binding transcription factor activity and structural molecular activity were upregulated, and most of genes affiliated with multicellular organismal process and extracellular region were downregulated. It was notably that fifteen genes affiliated with flagella and four genes affiliated with heat shock proteins were significantly upregulated. Meanwhile, nine genes affiliated with cytochrome and cytochrome oxidase, and five genes affiliated with TonB-dependent receptor, were significantly downregulated. However, eighteen genes with antioxidant activity categorized by GO analysis showed differential expressions. This overall survey of transcriptome and oxidative stress-relevant genes can contribute to understand the adaptive mechanism of Arctic bacteria. five significant upregulated genes and five significant downregulated genes were selected using qRT-PCR to cinduct the oxidative stress. overall survey of transcriptomic sequencing by RNA-Seq of the Pseudoalteromonas sp. A2, an isolate from seawater with high activity against H2O2
Project description:Upon biofilm formation, production of extracellular matrix components and alteration in physiology and metabolism allows bacteria to build up multicellular communities which can facilitate nutrient acquisition during unfavorable conditions and provide protection towards various forms of environmental stresses to individual cells. Thus, bacterial cells become tolerant against antimicrobials and the immune system within biofilms. In the current study, we evaluated the antibiofilm activity of the macrolides clarithromycin and azithromycin. Clarithromycin showed antibiofilm activity against rdar (red, dry and rough) biofilm formation of the gastrointestinal pathogen Salmonella typhimurium ATCC14028 Nalr at 1.56 µM subinhibitory concentration in standing culture and dissolved cell aggregates at 15 µM in a microaerophilic environment suggesting that the oxygen level affects the activity of the drug. Treatment with clarithromycin significantly decreased transcription and production of the rdar biofilm activator CsgD, with biofilm genes such as csgB and adrA to be consistently downregulated. While fliA and other flagellar regulon genes were upregulated, apparent motility was downregulated. RNA sequencing showed a holistic cell response upon clarithromycin exposure, whereby not only genes involved in the biofilm-related regulatory pathways, but also genes that likely contribute to intrinsic antimicrobial resistance, and the heat shock stress response were differentially regulated. Most significantly, clarithromycin exposure shifts the cells towards an apparent oxygen- and energy- depleted status, whereby the metabolism that channels into oxidative phosphorylation is downregulated, and energy gain by degradation of propane 1,2-diol, ethanolamine and L-arginine catabolism, potentially also to prevent cytosolic, is upregulated. This analysis will allow the subsequent identification of novel intrinsic antimicrobial resistance determinants.
Project description:Candida albicans is an opportunistic pathogen and responsible for candidiasis. C. albicans readily forms biofilms on various biotic and abiotic surfaces, and these biofilms can cause local and systemic infections. C. albicans biofilms are more resistant than its free yeast to antifungal agents and less affected by host immune responses. Transition of yeast cells to hyphal cells is required for biofilm formation and is believed to be a crucial virulence factor. In this study, six components of ginger were investigated for antibiofilm and antivirulence activities against a fluconazole-resistant C. albicans strain. It was found 6-gingerol, 8-gingerol, and 6-shogaol effectively inhibited biofilm formation. In particular, 6-shogaol at 10 µg/ml significantly reduced C. albicans biofilm formation but had no effect on planktonic cell growth. Also, 6-gingerol and 6-shogaol inhibited hyphal growth in embedded colonies and free-living planktonic cells, and prevented cell aggregation. Furthermore, 6-gingerol and 6-shogaol reduced C. albicans virulence in a nematode infection model without causing toxicity at the tested concentrations. Transcriptomic analysis using RNA-seq and qRT-PCR showed 6-gingerol and 6-shogaol induced several transporters (CDR1, CDR2, and RTA3), but repressed the expressions of several hypha/biofilm related genes (ECE1 and HWP1), which supported observed phenotypic changes. These results highlight the antibiofilm and antivirulence activities of the ginger components, 6-gingerol and 6-shogaol, against a drug resistant C. albicans strain.
Project description:Bacterial biofilm infections associated with wounded skin are prevalent, recalcitrant and in urgent need of treatments. Additionally, host responses in the skin to biofilm infections are not well understood. Here we employed a human organoid skin model to explore the transcriptomic changes of thermally-injured epidermis to Methicillin-resistant Staphylococcus aureus (MRSA) biofilm colonization. MRSA biofilm impaired skin barrier function, enhanced extracellular matrix remodelling, elicited inflammatory responses including IL-17, IL-12 family and IL-6 family interleukin signalling and modulated skin metabolism. Synthetic antibiofilm peptide DJK-5 effectively diminished MRSA biofilm associated with wounded human ex vivo skin. In the epidermis, DJK-5 shifted the overall skin transcriptome towards homeostasis including modulating the biofilm induced inflammatory response, promoting the skin DNA repair function, and downregulating MRSA invasion of thermally damaged skin. These data revealed the intrinsic promise of synthetic peptides in treating inflammation and biofilm infections.
Project description:Human SP-A1 and SP-A2, encoded by SFTPA1 and SFTPA2 and their genetic variants differentially impact alveolar macrophage (AM) functions and regulation, including the miRNome. single dose of SP-A exogenous treatment of SP-A-KO mice prior to infection, after infection, or at the time of infection significantly improved survival. we investigated the role of exogenous SP-A protein treatment on the regulation of AM miRNome in SP-A-KO mice at the time of infection. Towards this, SP-A-KO male and female mice were infected with K. pneumoniae alone or in combination with exogenous SP-A2 (1A0) protein for 6 h, and the expression levels of AM miRNAs, target mRNAs of the significant miRNAs, and pathways involved were studied. We found (i) significant differences in AM miRNome of KO in terms of sex and exposure; (ii) the expression of the overwhelming majority of miRNA targets in KO males were increased in response to infection and exogenous SP-A2 (1A0) protein treatment at the time of infection; (iii) miRNA-mRNA targets were involved in the pro-inflammatory response, anti-apoptosis, cell cycle, cellular growth and proliferation pathways. These data may assist in studying molecular mechanisms of exogenous SP-A mediated the AM miRNome regulation and potentially identify novel therapeutic targets for K. pneumoniae infection.