Project description:Pseudomonas fragi is the predominant bacterial species associated with spoiled aerobically stored chilled meat worldwide. It readily forms biofilms on meat under refrigerated temperature conditions used in meat industry. Biofilm growth leads to slime development on meat which becomes a major quality defect. In this research, RNA sequencing was carried out for the main stages of P. fragi strain 1793 grown on aerobically stored meat, kept at 10 °C. RNA was extracted at different stages of the biofilm cycle namely initiation, maturation and dispersal. The key objectives of this study was to investigate which genes are expressed at each of these stages as well as to understand the causes of P. fragi biofilm dipersal.
Project description:C. albicans is a dimorphic yeast which can switch from budding yeast and to hyphal forms and this property is essential for biofilm establishment and maturation. C. albicans undergoes this yeast-to-hyphal switch in response to high CO2. The purpose of this study is to use RNA-seq to investigate pathways whose genes are differentially expressed when C. albicans biofilms are grown in a physiologically relevant elevated (5%) CO2 environment compared to a low/atmospheric (0.03%) CO2 environment. We report that in C.albicans biofilms grown under 5% CO2 conditions, genes controlled by core biofilm regulatory transcription factors such as Brg1, Efg1, Ndt80, and Bcr1 are overall expressed at significantly higher levels compared to those grown in 0.03% CO2 conditions. We find that genes encoding glucose and amino acid transporters, as well as genes previously found to be involved in the response to Ketoconazole treatment, are significantly upregulated in 5% CO2 C. albicans biofilms. Overall, these data suggest a high CO2 environment enhances biofilm formation of C. albicans and may also increase antifungal tolerance of such biofilms.
Project description:Salmonella spp. biofilms have been implicated in persistence in the environment and plant surfaces. In addition, Salmonella is able to form biofilms on the surface on cholesterol gallstones. The ability of Salmonella spp. on these surfaces is superior to biofilm formation on surfaces on glass or plastic. Thus, we hypothesized that Salmonella gene expression is specific during biofilm development on cholesterol surfaces.
Project description:Salmonella spp. biofilms have been implicated in persistence in the environment and plant surfaces. In addition, Salmonella is able to form biofilms on the surface on cholesterol gallstones. The ability of Salmonella spp. on these surfaces is superior to biofilm formation on surfaces on glass or plastic. Thus, we hypothesized that Salmonella gene expression is specific during biofilm development on cholesterol surfaces. Flow through assays were performed whereby S. Typhimurium was inoculated into chambers coated with glass or cholesterol. At 24h post-inoculation, planktonic (from the flow through), biofilms (from glass or cholesterol) were collected. Thus we had 4 samples: Planktonic (2) and Biofilms (2), each with 2 biological replicates