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:The Antibiotic Resistant Sepsis Pathogens Framework Initiative aims to develop a framework dataset of 5 sepsis pathogens (5 strains each) using an integrated application of genomic, transcriptomic, metabolomic and proteomic technologies. The pathogens included in this initiative are: Escherichia coli, Klebsiella pneumoniae complex, Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae. This submission pertains to strain AJ218.
Project description:The Antibiotic Resistant Sepsis Pathogens Framework Initiative aims to develop a framework dataset of 5 sepsis pathogens (5 strains each) using an integrated application of genomic, transcriptomic, metabolomic and proteomic technologies. The pathogens included in this initiative are: Escherichia coli, Klebsiella pneumoniae complex, Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae. This submission pertains to strain KPC2.
Project description:Klebsiella pneumoniae is an important human pathogen, causing various infections. Apart from traditional virulence factors, there remains a significant gap in the discovery and research of new chromosomal virulence factors. CpxR is a two-component system (TCS) response regulator, but its impact on the virulence of Klebsiella pneumoniae have not been conclusively determined. For the effect of CpxR on K. pneumoniae virulence, the cpxR deletion(ΔcpxR) strain exhibited reduced serum resistance and attenuated pathogenicity in both Galleria mellonella larvae and mouse infection models compared to the wild-type strain. To identify CpxR-regulated virulence genes, RNA-seq analysis was conducted, followed by deletion of transcription downregulated genes in the ΔcpxR strain. Through serum resistance assays and Galleria mellonella infection experiments, a novel potential virulence factor, KPHS_28080, was identified. Deletion of KPHS_28080 impaired serum survival and proliferation in carbapenem-resistant strains HS11286 and hypervirulent strain ATCC 43816. Furthermore, the ATCC 43816 ΔKPHS_28080 strain showed significantly reduced colonization, proliferation, and multi-organ dissemination capacity in mice, accompanied by diminished pathogenicity. The KPHS_28080 promoter contains a conserved CpxR binding motif, where CpxR binding enhances promoter activity and elevates gene transcription. Sequence alignment revealed that KPHS_28080 is widely conserved across Klebsiella pneumoniae strains, establishing it as a novel chromosome-encoded virulence factor. These results provide a new insight into the CpxR regulation of K. pneumoniae virulence and chromosomal virulence factors.
Project description:The Antibiotic Resistant Sepsis Pathogens Framework Initiative aims to develop a framework dataset of 5 sepsis pathogens (Escherichia coli, Klebsiella pneumoniae complex, Staphylococcus aureus, Streptococcus pneumoniae and Streptococcus pyogenes, 5 strains each) using an integrated application of genomic, transcriptomic, metabolomic and proteomic technologies. This submission contains the results from six Klebsiella strains (four Klebsiella variicola: AJ005, AJ292, 03-311-0071, 04153260899A and two Klebsiella pneumoniae: AJ218, KPC2) grown in either RPMI or pooled human sera. Six replicates of each condition were subjected to shotgun proteomics and label-free MS1-based quantitation.
