title: Effects of Chlorine Stress on Pseudomonas aeruginosa Biofilm and Analysis of Related Gene Expressions.
abstract: Chlorine is deployed worldwide to clean waters and prevent water-originated illnesses. However, chlorine has a limited disinfection capacity against biofilms. Microorganisms form biofilms to protect themselves from biological threats such as disinfectant chemicals. Pseudomonas aeruginosa is an opportunistic pathogen and its biofilm form attaches to surfaces, living buried into exopolysaccharides, can be present in all watery environments including tap water and drinking water. This research aimed to study the biofilm trigger mechanism of the opportunistic pathogen P. aeruginosa PAO1 strain, which is known to form biofilm in water supply systems and human body, under chlorine stress levels. In addition to biofilm staining, certain genes that are relevant to the stress condition were selected for gene expression analysis. The bacteria cultures were grown under chlorine stress with concentrations of 0.5, 0.7 and 1 mg/l. Six gene regions were determined related to biofilm and stress response: rpoS, bifA, migA, katB, soxR, and algC. Biofilm formation was analyzed by basic fuchsin staining, and gene expressions were quantified by quantitative real-time PCR. According to the results, highest biofilm production was observed in P. aeruginosa PAO1 wild strain under no stress conditions. Higher biofilm amounts were observed for bacteria under 0.5 and 0.7 mg/l chlorine stress compared to 1 mg/l chlorine stress.
authors.affiliation: Department of Biology, Art and Science Faculty, Marmara University, Goztepe Campus, 34722, Istanbul, Turkey.
authors.forename: Özge
authors.initials: Ö
authors.lastname: Kekeç
authors.affiliation: Department of Biology, Art and Science Faculty, Marmara University, Goztepe Campus, 34722, Istanbul, Turkey.
authors.forename: Barış
authors.initials: B
authors.lastname: Gökalsın
authors.affiliation: Department of Nutrition and Dietetics, Yeditepe University, Istanbul, Turkey.
authors.forename: İskender
authors.initials: İ
authors.lastname: Karaltı
authors.affiliation: Department of Biology, Art and Science Faculty, Marmara University, Goztepe Campus, 34722, Istanbul, Turkey.
authors.forename: Figen Esin
authors.initials: FE
authors.lastname: Kayhan
authors.affiliation: Department of Biology, Art and Science Faculty, Marmara University, Goztepe Campus, 34722, Istanbul, Turkey. csesal@marmara.edu.tr.
authors.forename: Nüzhet Cenk
authors.initials: NC
authors.lastname: Sesal
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D018441:Biofilms / Q000187:drug effects*; D002713:Chlorine / Q000494:pharmacology*; D004202:Disinfectants / Q000494:pharmacology*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics* / Q000502:physiology; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D001426:Bacterial Proteins; D004202:Disinfectants; D002713:Chlorine