Project description:The study aimed to characterize plasmids mediating carbepenem resistance in Klebsiella pneumoniae in Pretoria, South Africa. We analysed 56 K. pneumoniae isolates collected from academic hospital around Pretoria. Based on phenotypic and molecular results of these isolates, 6 representative isolates were chosen for further analysis using long reads sequencing platform. We observed multidrug resistant phenotype in all these isolates, including resistance to aminoglycosides, tetracycline, phenicol, fosfomycin, floroquinolones, and beta-lactams antibiotics. The blaOXA-48/181 and blaNDM-1/7 were manily the plasmid-mediated carbapenemases responsible for carbapenem resistance in the K. pneumoniae isolates in these academic hospitals. These carbapenemase genes were mainly associated with plasmid replicon groups IncF, IncL/M, IncA/C, and IncX3. This study showed plasmid-mediated carbapenemase spread of blaOXA and blaNDM genes mediated by conjugative plasmids in Pretoria hospitals.
Project description:Salmonella enterica serovar Typhimurium (S. Typhimurium) definitive phage type 104 (DT104) has caused significant morbidity and mortality in humans and animals for almost three decades. We have completed the full DNA sequence of one DT104 strain, NCTC13348 and show that the main differences between the genome of this isolate and the previously sequenced S. Typhimurium LT2 lie in integrated prophage elements and the Salmonella Genomic Island 1 encoding antibiotic resistance genes. Thirteen isolates of S. Typhimurium DT104 with different pulsed field gel electrophoresis (PFGE) profiles were analyzed by multi locus sequence typing (MLST), plasmid profiling, hybridization to a Pan-Salmonella DNA microarray and prophage-based multiplex PCR. All the isolates belonged to a single MLST type ST19. Microarray data demonstrated that the 13 DT104 isolates were remarkably conserved in gene content. The PFGE band-size differences in these isolates could be explained to a great extent by changes in prophage and plasmid content. Thus, here the nature of variation in different S. Typhimurium DT104 isolates is further defined at the genome level illustrating how this phage type is evolving over time.
Project description:Unknown are the mechanisms of tolerance and persistence associated to several compounds in A.baumannii clinical isolates. Using transcriptomical and microbiological studies, we found a link between bacterial tolerance mechanisms to clorhexidine as well as the development of persistence in presence of imipenem in an A.baumannii strain belonging to ST-2 clinical clone (carbapenem-resistant with OXA-24 ß-lactamase and AbkAB TA system by plasmid). Interestingly, in A.baumannii ATCC17978 strain (carbapenem-susceptible isolate which carries AbkAB TA system by plasmid) showed persistence in presence of imipenem.
Project description:In this study, we carried out RNA sequencing (RNAseq) of liver RNA harvested from wild sardine and mackerel exposed under laboratory conditions to EE2 and developed an analytical framework for transcriptomic analyses of species with limited genomic information. EE2 exposure altered expression patterns of key genes involved in important metabolic and physiological processes. The systems approach presented here provides a powerful tool for obtaining a comprehensive picture of endocrine disruption in aquatic organisms.
Project description:The integrin α11-overexpressing transgenic mouse strain was generated to further understand the function of α11, after generation of our integrin α11-KO strain. Analysis of the strain showed that integrin α11 was highly expressed in heart, which correlated with a fibrotic heart phenotype. To understand the molecular mechanisms underlying this phenotype, we then performed Microarray to investigate the differentially expressed genes between the WT and TG mice (α11-overexpressing mice) which may result from integrin α11 overexpression. The microarray was performed on RNA-isolates from the heart apex of 1-year-old WT (n=4) and α11-TG (n=6) mice. Total RNA isolation was performed using RNeasy Fibrous Tissue Mini Kit (Qiagen) in accordance with the manufacturerâs protocol. Quality of RNA samples was assessed using Agilent Bioanalyzer 2100. Microarray was carried out at the Norwegian Microarray Consortium/University of Bergen Microarray Core Facility at Haukeland University Hospital. Illumina Bead Array Technology was used, and the raw microarray data was quality examined in GenomeStudio. Differentially expressed genes were analysed using the Ingenuity Pathways Analysis (IPA) software (Ingenuity Systems, Redwood City, CA).
Project description:A collection of 61 Salmonella enterica serovar Typhimurium (S. Typhimurium) of animal and human origin, matched as closely as possible by phage type, antimicrobial resistance pattern and place / time of isolation, and sourced from farms or hospitals in Scotland, were analysed by antimicrobial susceptibility testing, phage typing, pulsed field gel electrophoresis (PFGE), plasmid profiling and DNA microarrays. PFGE of all 61 isolates revealed ten PFGE profiles, which clustered by phage type and antibiotic resistance pattern, with human and animal isolates distributed between PFGE profiles. Analysis of 23 representative S. Typhimurium strains hybridised to a composite Salmonella DNA microarray identified a small number of specific regions of genome variation between different phage types and PFGE profiles. These variable regions of DNA were typically located within prophage-like elements. Simple PCR assays were subsequently designed to discriminate between different isolates from the same geographical region.