Project description:Biocides are chemical compounds widely used in hospital settings for a variety of purposes, but mainly for disinfection. The chemical properties of a biocide, as well as the biocide concentration, influence which cellular targets are affected. Exposure of bacteria to residual concentrations of biocides could lead to development of increased resistance towards the biocide in use, as well as cross-resistance towards other antimicrobials, including antibiotics. The aim of this study was to examine whether biocides could induce any potentially relevant genes that could affect pathogen's drug resistance or fitness. By examining global gene expression of the uropathogenic Escherichia coli CFT073 after exposure to subinhibitory concentrations of four biocides (benzalkonium chloride - BAC, chlorhexidine - CHX, hydrogen peroxide - H2O2, triclosan - TSN), we found that each biocide changed expression of different groups of genes and that exposure to benzalkonum chloride caused changes in expression of the largest number of genes among all biocides. In general, the four biocides tested in this study at subinhibitory concentrations did not increase the resistance potential of the pathogen to other antimicrobials. We could, however, identify clusters of genes that could possibly help the strain to grow in the presence of a biocide in the medium.
Project description:Biocides are chemical compounds widely used in hospital settings for a variety of purposes, but mainly for disinfection. The chemical properties of a biocide, as well as the biocide concentration, influence which cellular targets are affected. Exposure of bacteria to residual concentrations of biocides could lead to development of increased resistance towards the biocide in use, as well as cross-resistance towards other antimicrobials, including antibiotics. The aim of this study was to examine whether biocides could induce any potentially relevant genes that could affect pathogen's drug resistance or fitness. By examining global gene expression of the uropathogenic Escherichia coli CFT073 after exposure to subinhibitory concentrations of five biocides (benzalkonium chloride - BAC, chlorhexidine - CHX, ethanol - EtOH, hydrogen peroxide - H2O2, triclosan - TSN), we found that each biocide changed expression of different groups of genes and that exposure to ethanol caused changes in expression of the largest number of genes among all biocides. In general, the five biocides tested in this study at subinhibitory concentrations did not increase the resistance potential of the pathogen to other antimicrobials. We could, however, identify clusters of genes that could possibly help the strain to grow in the presence of a biocide in the medium. A culture of E. coli CFT073 without any biocide treatment served as the control sample. That culture was grown under the exact same conditions as the five biocide-treated samples. Each sample was collected in three biological replicates at the mid-exponential phase of growth.
Project description:The present project investigates transcriptomics changes in laboratory mutants of Salmonella typhimurium SL1344 obtained by pre-exposure to biocides, including triclosan (TRI), benzalkonium chloride (BZC), and chlorexidine (CHX), and antibiotics including Ampicillin (AP) and ciprofloxacin (Cip), as well as in natural isolates selected for their resistance to these same biocides. Changes in gene expression were investigated using a 12k combimatrix customarray, design-based on the genome of SL1344 as well as a variety of genes of plasmid origins.
Project description:Origanum oil (ORO), garlic oil (GAO), and peppermint oil (PEO) were shown to effectively lower methane production, decrease abundance of methanogens, and change abundances of several bacterial populations important to feed digestion in vitro. In this study, the impact of these essential oils (EOs, at 0.50 g/L), on the rumen bacterial community composition was further examined using the recently developed RumenBactArray.
Project description:Because antibiotics have been widely used to prevent severe losses due to infectious fishery diseases, the liberal application and overuse of antibiotics has led to the spread and evolution of bacterial resistance, food safety hazards, and environmental issues. The use of some antibiotics, including florfenicol and enrofloxacin, is allowed in aquaculture in China. Accordingly, to better address the concerns and questions associated with the impact of administered enrofloxacin and florfenicol to grass carp, here we investigated the immune response, bacterial diversity, and transcriptome of the intestine of C. idella treated with these oral antibiotics. The aim of this study was to provide an in-depth evaluation of the antibiotic-induced patterns and dynamics of the microbiota grass carp and the potential mechanism involved.
Project description:Study on genome-wide expression in L.monocytogenes str4b F2365 exposed to five different biocides at three different concentrations
Project description:Human BEAS-2B bronchial epithelial cells were exposed directly at the air-liquid interphase towards exhaust gas and particles of a ship engine. The goal was to compare the responses towards different fuel combustions. The engine run either on diesel fuel (DF) or on Heavy Fuel Oil (HFO).