Project description:Antimicrobial exposure can potentially lead to increased antimicrobial resistance plasmid transfer. RNA sequencing data was collected from conjugal pairs of Salmonella enterica and Escherichia coli exposed or not exposed to tetracycline over a time course to determine differences in transcript numbers associated with conjugation and tetracycline exposure. The samples were sequenced on the Illumina HiSeq X10 platform with the 150-bp paired-end kit. Among the most highly up-regulated genes in the tetracycline exposed samples were also tetracycline efflux pump genes across the timepoints. In addition, some conjugal transfer-associated genes (e.g. traJ and traA) were upregulated in the tetracycline exposed samples.
Project description:Purpose: We use the gene expression data to estimate the effects of tetracycline on gene expression and average ribosome density. Methods: The mRNAs were extracted with TRIzol reagent. The mRNAs were fragmented into 280 bp and the sequencing process was conducted on HiSeq 2500 platform. We use cutadapt, bowtie2, Plastid and DEseq2 software to analyze the expression levels of genes in two Escherichia coli strains. Results: The gene expression in EF4 knockout Escherichia coli strain was similar with BW25113 strain under normal condition. Under tetracycline treatment, many genes' expression were differentially regulated. Interestingly, we found that the gene expression of ribosomal proteins was up-regulated in WT strain comparing with EF4 knockout E. coli strain. Conclusions: Our results suggest that EF4 affects the average ribosome density and global gene expression in two Escherichia coli strain under tetracycline treatment.
Project description:Transcriptional profiling of A. oleivorans DR1 cells harboring pAST2. Plasmid pAST2 is a tetracycline-resistance plasmid which was isolated from activated sludge (Hong et al., 2014). The complete plasmid sequence was deposited in the National Center for Biotechnology Information (NCBI) GenBank under accession number KC734561 [PMID: 24337108].
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:Horizontal gene transfer (HGT) is the major mechanism responsible for spread of antibiotic resistance. Antibiotic treatment has been suggested to promote HGT, either by directly affecting the conjugation process itself or by selecting for conjugations subsequent to DNA transfer. However, recent research suggests that the effect of antibiotic treatment on plasmid conjugation frequencies, and hence the spread of resistance plasmids, may have been overestimated. We addressed the question by quantifying transfer proteins and conjugation frequencies of a blaCTX-M-1 encoding IncI1 resistance plasmid in Escherichia coli MG1655 in the presence and absence of therapeutically relevant concentrations of cefotaxime (CTX). Analysis of the proteome by iTRAQ labeling and liquid chromatography tandem mass spectrometry revealed that Tra proteins were significantly up regulated in the presence of CTX. The up-regulation of the transfer machinery was confirmed at the transcriptional level for five selected genes. The CTX treatment did not cause induction of the SOS39 response as revealed by absence of significantly regulated SOS associated proteins in the proteome and no significant up-regulation of recA and sfiA genes. The frequency of plasmid conjugation, measured in an antibiotic free environment, increased significantly when the donor was pre-grown in broth containing CTX compared to growth without this drug, regardless of whether blaCTX-M-1 was located on the plasmid or in trans on the chromosome. The results shows that antibiotic treatment can affect expression of a plasmid conjugation machinery and subsequent DNA transfer.
Project description:Comparison of the whole genome gene expression level of an enrofloxacin and tetracycline resistant E. coli strain with the wildtype it was derived from. The process of drug adaptation of E. coli MG1655 wildtype cells is further descibed in van der Horst, M, J.M. Schuurmans, M. C. Smid, B. B. Koenders, and B. H. ter Kuile (2011) in Microb. Drug Resist. 17:141-147. Resistance to amoxicillin was induced in E. coli by growth in the presence of stepwise increasing antibiotic concentrations. To investigate consequences of the aquisition of amoxicillin resistance the transcriptomic profile of sensitive and resistant cells was compared in the absence and presence of sub-inhibitory (0.25xMIC) amoxicillin concentrations was compared.