Project description:We performed differential RNA-seq of two Staphylococcus epidermidis clinical isolates (PS2 and PS10) to compare their transcription profiles. The isolates were originally obtained from blood cultures during a systemic infection in an immunocompromised patient (Weisser et al. 2010. J Clin Microbiol 48: 2407-2412). They are of clonal origin, but differ phenotypically with respect to extracellular biofilm matrix production. Thus PS2, isolated in the early stage of the infection, forms a weak biofilm mediated by protein-protein interactions, while PS10, which was obtained at the end of the infection course, forms a strong biofilm through production of a polysaccharide intercellular adhesin (PIA) extracellular biofilm matrix. Transcription profiling by dRNA-seq was performed to elucidate differentially expressed metabolic pathways and regulators contributing to the switch in extracellular biofilm matrix producction between the two isolates.
Project description:Persistence of Listeria monocytogenes in retail deli environments is a serious food safety issue, potentially leading to cross-contamination of ready-to-eat foods such as deli meats, salads, and cheeses. We previously discovered strong evidence of L. monocytogenes persistence in delis across multiple states. We hypothesized that this was correlated with isolates’ innate characteristics, such as biofilm-forming capacity or gene differences.We further chose four isolates for RNA-sequencing analysis and compared their global biofilm transcriptome to their global planktonic transcriptome. Analysis of biofilm vs planktonic gene expression did not show the expected differences in gene expression patterns. Overall, L. monocytogenes persistence in the deli environment is likely a matter of poor sanitation and/or facility design, rather than isolates’ biofilm-forming capacity, sanitizer tolerance, or genomic content
Project description:Comparative genomics has greatly facilitated the identification of shared as well as unique features among individual cells or tissues, and thus offers the potential to find disease markers. While proteomics is recognized for its potential to generate quantitative maps of protein expression, comparative proteomics in bacteria has been largely restricted to the comparison of single cell lines or mutant strains. In this study, we used a data independent acquisition (DIA) technique, which enables global protein quantification of large sample cohorts, to record the proteome profiles of overall 27 whole genome sequenced and transcriptionally profiled clinical isolates of the opportunistic pathogen Pseudomonas aeruginosa. Analysis of the proteome profiles across the 27 clinical isolates grown under planktonic and biofilm growth conditions led to the identification of a core biofilm-associated protein profile. Furthermore, we found that protein-to-mRNA ratios between different P. aeruginosa strains are well correlated, indicating conserved patterns of post-transcriptional regulation. Uncovering core regulatory pathways, which drive biofilm formation and associated antibiotic tolerance in bacterial pathogens, promise to give clues to interactions between bacterial species and their environment and could provide useful targets for new clinical interventions to combat biofilm-associated infections.
Project description:Biofilm lifestyle is critical for bacterial pathogens to colonize and protect themselves from host immunity and antimicrobial chemicals in plants and animals. The formation and regulation mechanism of phytobacterial biofilm are still obscure. Here, we found that Ralstonia solanacearum Resistance to ultraviolet C (RuvC) is highly abundant in biofilm and positively regulates pathogenicity by governing systemic movement in tomato xylem. RuvC protein accumulates at the later stage of biofilm and specifically targets the Holliday junction (HJ) like structures to disrupt biofilm extracellular DNA (eDNA) lattice, thus facilitating biofilm dispersal. Recombinant RuvC protein can resolve extracellular HJ prevent bacterial biofilm formation. Heterologous expression of R. solanacearum or Xanthomonas oryzae pv. oryzae RuvC with plant secretion signal in tomato or rice confers resistance to bacterial wilt or bacterial blight disease, respectively. Plant chloroplast localized HJ resolvase monokaryotic chloroplast 1 (MOC1) which is structural similar to bacterial RuvC shows a strong inhibit effect on bacterial biofilm formation. Re-localization of SlMOC1 to apoplast in tomato roots leads to increase resistance to bacterial wilt. Our novel finding reveals a critical pathogenesis mechanism of R. solanacearum and provides an efficient biotechnology strategy to improve plant resistance to bacteria vascular disease.
Project description:In this study, the adhesive and biofilm forming properties of ten clinical and ten commensal S. haemolyticus isolates were examined using standard adhesion and biofilm assays, in addition we selected one clinical S. haemolyticus isolate for bacterial surface shaving. The surface shaving approach was used to identify upregulated S. haemolyticus proteins subsequent to human keratinocyte colonization. Relative quantification of up and downregulated proteins was performed by labelling proteins with tandem mass tags (TMT), prior to Mass Spectrometry analysis.
Project description:Prolific heterotrophic biofilm growth is a common occurrence in airport receiving streams containing deicer and anti-icer runoff. This study investigated relations of heterotrophic biofilm prevalence and community composition to environmental conditions at stream sites upstream and downstream of Milwaukee Mitchell International Airport in Milwaukee, WI, during two deicing seasons (2009–2010 and 2010–2011). Modern genetic tools (such as microarray) have not previously been applied to biofilm communities in this type of setting. We used microarray results to characterize biofilm community composition as well as the response of the biofilm community to environmental factors (i.e., organic content (using chemical oxygen demand concentration) and temperature).
Project description:Microarray hybridization analysis was conducted to identify genes that may affect biofilm formation. Isolates from the 50 clinical isolates, two from LSG (strain number 2 and 7) and two from HSG donors (strain number 10 and 33) were selected.