Project description:We developed a spatially resolved method to profile the spatial transcriptome of biofilm. In detail, we used fluorescent dyes to label the different regions of biofilm cultured in a microfluidic chip. After staining, the bacterial cells in biofilm were sorted into relevant bins according to their spatial information marked by the fluorescent pattern. Finally, miniBac-seq (RNA-seq) method was applied to capture the transcriptome of each bin.
Project description:The objective of the current study was to understand the glutaraldehyde resistance mechanisms in P. fluorescens and P. aeruginosa biofilms. Glutaraldehyde is a common biocide used in various industries to control the microbial growth. Recent reports of emergence of glutaraldehyde resistance in several bacterial species motivated this study to understand the genetic factors responsible got glutaraldehyde resistance. Using a combination of phenotypic assays, chemical genetic assays and RNA-seq, we demonstrate that novel efflux pump, polyamine biosynthesis, lipid biosynthesis and phosphonate degradation play significant role in glutaraldehyde resistance and post-glutaraldehyde recovery of Psudomonad biofilms. Examination of P. fluorescens 72 h biofilm transcriptome was elucidated upon exposure to glutaraldehyde. The results were confirmed using qRT--PCR and chemical genetic appraoches in P. fluorescens and P. aeruginosa.
Project description:Bacteria assume distinct lifestyles during the planktonic and biofilm modes of growth. In biofilms, they are more tolerant to antibiotics and can evade the immune system response more effectively. However, little is known regarding the molecular determinants involved in biofilm formation by Gardnerella vaginali, the predominant species found in bacterial vaginosis (BV). Hence, to gain insight into the pathogenesis of G. vaginalis, we carried out a comparative transcriptomic analysis between planktonic and biofilm phenotypes, using RNA-sequencing. The major alterations observed were related with the transcription of genes involved in cell wall biogenesis and typical stress factors, in which was found significantly up-regulated in biofilms, resulting in a protected mode of bacterial growth. In addition, biofilm phenotype was characterized by low metabolic activity, which is appropriate to guarantee long term survival during BV recurrence.
Project description:Transcriptional profiling of Candida albicans cells grown under planktonic and biofilm-inducing conditions, comparing SN76 and sfl1Δ/sfl1Δ strains. Goal was to study the effect of SFL1 deletion on the transcriptomic profile of C. albicans planktonic and biofilm cells under acidic conditions, in order to reveal the function of the Sfl1 transcription factor in C. albicans biofilm development.
Project description:The recovery of other pathogens in COVID-19 patients has been reported. The presence of either co-infection or superinfection with bacterial pathogens was associated with poor outcomes, including increased mortality. The recognition of possibility of SARS-CoV-2 co-infection is important as it enables the implementation of appropriate infection control measures and therapy. This is a proof-of-concept study uses in vitro approaches (including crystal violet assay, microrheology, and LC-MS-based prote-omics) to investigate the interaction between SARS-CoV-2 and biofilms of bacteria (S. pneumoniae and S. aureus). SARS-CoV-2 spike protein S1 subunit was found to suppress biofilm formation of both bacteria. The effect of coronavirus and spike protein on bac-terial biofilm was supported by proteomics data that shows variations in proteins in-volved in quorum sensing and biofilm formation/maturation. Preliminary in vitro data suggest that dispersion of opportunistic pathogens from biofilm may be associated with poor prognosis in co-infections. However, further investigations are needed to establish bacterial biofilm as a risk factor for secondary pneumonia in COVID-19 patients.
Project description:To combat dental implant-associated infections, there is a need for novel materials which effectively inhibit bacterial biofilm formation. In the present study, a titanium surface functionalization based on the “slippery liquid-infused porous surfaces” (SLIPS) principle was analyzed in an oral flow chamber system. The immobilized liquid layer was stable over 13 days of continuous flow. With increasing flow rates, the surface exhibited a significant reduction in attached biofilm of both the oral initial colonizer Streptococcus oralis and an oral multi-species biofilm composed of S. oralis, Actinomyces naeslundii, Veillonella dispar and Porphyromonas gingivalis. Using single cell force spectroscopy, reduced bacterial adhesion forces on the lubricant layer could be measured. Gene expression patterns in biofilms on SLIPS, on control surfaces and planktonic cultures were also compared. For this purpose, the genome of S. oralis strain ATCC® 9811TM was sequenced using PacBio Sequel technology. Even though biofilm cells showed clear changes in gene expression compared to planktonic cells, no differences could be detected between bacteria on SLIPS and on control surfaces. Therefore, it can be concluded that the ability of liquid-infused titanium to repel biofilms is solely due to weakened bacterial adhesion to the underlying liquid interface.
