Project description:In this study, we analyzed the expression profiles of a virulence plasmid-cured strain and wild-type strain of shigella flexneri. The results showed that the genes of glp regulon were upregulated in mutant bacteria in stationary phase cultures.
Project description:We evaluated the transcriptome changes induced by infection of Hela 229 cells with Shigella flexneri. The sample set consists of a control (mock), total population of infected sample and infected sample sorted into Shigella positive and Shigella negative population.
Project description:In this study, we analyzed the expression profiles of a virulence plasmid-cured strain and wild-type strain of shigella flexneri. The results showed that the genes of glp regulon were upregulated in mutant bacteria in stationary phase cultures. The two strains were cultured in LB broth into log-phase and stationary phase respectively. Then, the total RNAs were extracted and analyzed by Nimblegen biochips.
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:In most eukaryotes and bacteria, queuosine (Q) replaces the guanosine at the wobble position of tRNAs harboring a GUN anticodon. To faithfully detect Q-modification in RNAs from Schizosaccharomyces pombe and Shigella flexneri, Q-MaP-Seq was established and applied to tRNAs from S. pombe WT (AEP1) cells and Shigella flexneri WT cells and tgt∆ cells. Q-modification of in vitro-transcribed RNAs and RNAs isolated from S. pombe and S. flexneri followed by reverse transcription using the RT-active DNA polymerase variant RT-KTq I614Y and sequencing of unmodified compared to modified RNAs allowed identification of Q-sites within tRNAs.
Project description:Many human Gram-negative bacterial pathogens express a Type Three Secretion Apparatus (T3SA), including among the most notorious Shigella spp., Salmonella enterica, Yersinia enterocolitica and enteropathogenic Escherichia coli (EPEC). These bacteria express on their surface multiple copies of the T3SA that mediate the delivery into host cells of specific protein substrates critical to pathogenesis. Shigella spp. are Gram-negative bacterial pathogens responsible for human bacillary dysentery. The effector function of several Shigella T3SA substrates has largely been studied but their potential cellular targets are far from having been comprehensively delineated. In addition, it is likely that some T3SA substrates have escaped scrutiny as yet. Indeed, sequencing of the virulence plasmid of Shigella flexneri has revealed numerous open reading frames with unknown functions that could encode additional T3SA substrates. Taking advantage of label-free mass spectrometry detection of proteins secreted by a constitutively secreting strain of S. flexneri, we identified five novel substrates of the T3SA. We further confirmed their secretion through the T3SA and translocation into host cells using b-lactamase assays. The coding sequences of two of these novel T3SA substrates (Orf13 and Orf131a) have a guanine-cytosine content comparable to those of T3SA components and effectors. The three other T3SA substrates identified (Orf48, Orf86 and Orf176) have significant homology with antitoxin moieties of type II Toxin-Antitoxin systems usually implicated in the maintenance of low copy plasmids. While Orf13 and Orf131a might constitute new virulence effectors contributing to S. flexneri pathogenicity, potential roles for the translocation into host cells of antitoxins or antitoxin-like proteins during Shigella infection are discussed.
Project description:To find the alterations of expression profiles of shigella flexneri, we performed DNA chip analysis and proteomic analysis at the same time.
