Project description:This study aims to determine the epidemiology of Enterobacteriaceae resistant to antibiotics of last resort in pregnant women in labour at a tertiary hospital, Pretoria, South Africa. Rectal swabs shall be used to screen for colonisation with CRE and colistin-resistant Enterobacteriales in pregnant women during labour. Carbapenem and colistin-resistant Enterobacterales can cause the following infections: bacteraemia; nosocomial pneumonia; urinary tract infections, and intra-abdominal infections. Due to limited treatment options, infections caused by these multidrug-resistant organisms are associated with a mortality rate of 40-50%. Screening for colonisation of carbapenem-resistant Enterobacteriaceae (CRE) and colistin-resistant Enterobacteriaceae will help implement infection and prevention measures to limit the spread of these multidrug-resistant organisms.
Project description:Colistin is a crucial last-line drug used for the treatment of life-threatening infections caused by multi-drug resistant strains of the Gram-negative bacteria, Acinetobacter baumannii. However, colistin resistant A. baumannii isolates can be isolated following failed colistin therapy. Resistance is most often mediated by the addition of phosphoethanolamine (pEtN) to lipid A by PmrC, following missense mutations in the pmrCAB operon encoding PmrC and the two-component signal transduction system PmrA/PmrB. We recovered an isogenic pair of A. baumannii isolates from a single patient before (6009-1) and after (6009-2) failed colistin treatment that displayed low/intermediate and high levels of colistin resistance, respectively. To understand how increased colistin-resistance arose, we genome sequenced each isolate which revealed that 6009-2 had an extra copy of the insertion sequence element ISAba125 within a gene encoding an H-NS-family transcriptional regulator. Consequently, transcriptomic analysis of the clinical isolates identified was performed and more than 150 genes as differentially expressed in the colistin-resistant, hns mutant, 6009-2. Importantly, the expression of eptA, encoding a second lipid A-specific pEtN transferase, but not pmrC, was significantly increased in the hns mutant. This is the first time an H-NS-family transcriptional regulator has been associated with a pEtN transferase and colistin resistance.
2018-02-19 | GSE107964 | GEO
Project description:Whole genome sequencing of Enterobacteriaceae with mcr-mediated colistin resistance
Project description:The transcriptional, epigenomic, and genomic profiles of K. pneumoniae isolates were characterised to identify novel colistin and carbapenem resistance mechanisms. The genomic DNA and total RNA of the isolates were isolated and sequenced on PacBio.
2022-11-07 | GSE217148 | GEO
Project description:First report of mcr-1-mediated colistin resistance in Enterobacteriaceae from human clinical isolates in Colombia.
Project description:Here we investigated colistin effects on A. baumannii, employing a Mass spectrometry approach and comparing a colistin-susceptible multidrug-resistantclinical isolate to its colistin-dependent subpopulation obtained by subsequent passages in moderate colistin concentrations. Colistin dependence might represent a stepping-stone to resistance, but the mechanisms of colistin dependence are far from clear.
Project description:We report the transcriptional expression from wild type, ΔphoPQ, and ΔpmrAB to understand their contribution to colistin resistance.
Project description:Identification of mobile colistin resistance genes (mcr-1.1, mcr-5, mcr-8.1) in Enterobacteriaceae of human and animal origins, Nigeria.
