Project description:This SuperSeries is composed of the following subset Series: GSE35746: Comparative analysis of regulatory elements between Escherichia coli and Klebsiella pneumoniae by genome-wide transcription start site profiling [tiling arrays] GSE35821: Comparative analysis of regulatory elements between Escherichia coli and Klebsiella pneumoniae by genome-wide transcription start site profiling [TSS-Seq] Refer to individual Series
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:Screening of 14 novel proteins derived from Klebsiella pneumoniae MGH 78578 identified prior via screening of cDNA libraries. The full-length proteins were attached using a specific HaloTag to their corresponding ligand surface, HaloLink. Screening was performed using two different polyclonal antibodies to Klebsiella pneumoniae (Acris AP00792PU-N and Abcam ab20947) and detection achieved by Goat polyclonal to rabbit IgG conjugated with Chromeo-546 (Abcam ab60317). In order to assess their potential immungenic nature and rank the proteins investigated, comparative analysis using already described antigens from K. pneumoniae were used in the assay.
Project description:Antibiotic use can lead to expansion of multi-drug resistant pathobionts within the gut microbiome that can cause life-threatening infections. Selective alternatives to conventional antibiotics are in dire need. Here, we describe a Klebsiella PhageBank that enables the rapid design of antimicrobial bacteriophage cocktails to treat multi-drug resistant Klebsiella pneumoniae. Using a transposon library in carbapenem-resistant K. pneumoniae, we identified host factors required for phage infection in major Klebsiella phage families. Leveraging the diversity of the PhageBank and experimental evolution strategies, we formulated combinations of phages that minimize the occurrence of phage resistance in vitro. Optimized bacteriophage cocktails selectively suppressed the burden of multi-drug resistant K. pneumoniae in the mouse gut microbiome and drove bacterial populations to lose key virulence factors that act as phage receptors. Further, phage-mediated diversification of bacterial populations in the gut enabled co-evolution of phage variants with higher virulence and a broader host range. Altogether, the Klebsiella PhageBank represents a roadmap for both phage researchers and clinicians to enable phage therapy against a critical multidrug-resistant human pathogen.
Project description:Klebsiella pneumoniae is an arising threat to human health. However, host immune responses in response to this bacterium remain to be elucidated. The goal of this study was to identify the dominant host immune responses associated with Klebsiella pneumoniae pulmonary infection. Pulmonary mRNA profiles of 6-8-weeks-old BALB/c mice infected with/without Klebsiella pneumoniae were generated by deep sequencing using Illumina Novaseq 6000. qRT–PCR validation was performed using SYBR Green assays. Using KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis, we identified several immune associated pathways, including complement and coagulation cascades, Toll-like receptor signaling pathway, Rap1 signaling pathway, chemokine signaling pathway, TNF signaling pathway, phagosome and NOD-like receptor signaling pathway, were involved in Klebsiella pneumoniae pulmonary infection. Using ICEPOP (Immune CEll POPulation) analysis, we found that several cell types were involved in the host immune response to Klebsiella pneumoniae pulmonary infection, including dendritic cells, macrophages, monocytes, NK (natural killer) cells, stromal cells. Further, IL-17 chemokines were significantly increased during Klebsiella pneumoniae infection. This study provided evidence for further studying the pathogenic mechanism of Klebsiella pneumoniae pneumonia infection.
Project description:Screening of 14 novel proteins derived from Klebsiella pneumoniae MGH 78578 identified prior via screening of cDNA libraries. The full-length proteins were attached using a specific HaloTag to their corresponding ligand surface, HaloLink. Screening was performed using two different polyclonal antibodies to Klebsiella pneumoniae (Acris AP00792PU-N and Abcam ab20947) and detection achieved by Goat polyclonal to rabbit IgG conjugated with Chromeo-546 (Abcam ab60317). In order to assess their potential immungenic nature and rank the proteins investigated, comparative analysis using already described antigens from K. pneumoniae were used in the assay. Each microarray was seperated into different incubation chambers using the 16-well ProPlate (Grace Biolabs) multi-well gaskets. As positive references ompA and mdh were used. For negative control gapA was used and the crude lysates of the expression host (Acella E.coli) and buffer were spotted as well.Samples and controls were spotted with five replicates each. Incubation was performed using different antibodies reactive to K. pneumoniae.