ORCID Profile
0000-0003-0633-889X
Current Organisation
University of Oxford
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Publisher: American Society for Microbiology
Date: 03-2004
DOI: 10.1128/JCM.42.3.1337-1340.2004
Abstract: A LightCycler real-time PCR hybridization probe-based assay which detects a partial Klebsiella pneumoniae 16S rRNA gene was developed for the rapid identification of K. pneumoniae directly from growth-positive blood culture bottles (BACTEC 9240 system) within 2 h. No cross-reactivity was observed with 65 negative-control blood cultures that grew bacteria other than K. pneumoniae and 48 negative blood cultures from double-blind experiments, thus demonstrating 100% specificity when compared to results of conventional biochemical characterization. The assay also showed 100% sensitivity, as it correctly identified all 142 positive-control blood cultures and 4 from double-blind trials.
Publisher: Springer Science and Business Media LLC
Date: 17-01-2018
DOI: 10.1038/S41467-017-02540-X
Abstract: Mucosal-associated invariant T (MAIT) cells are innate-like T cells that can detect bacteria-derived metabolites presented on MR1. Here we show, using a controlled infection of humans with live Salmonella enterica serovar Paratyphi A, that MAIT cells are activated during infection, an effect maintained even after antibiotic treatment. At the peak of infection MAIT cell T-cell receptor (TCR)β clonotypes that are over-represented prior to infection transiently contract. Select MAIT cell TCRβ clonotypes that expand after infection have stronger TCR-dependent activation than do contracted clonotypes. Our results demonstrate that host exposure to antigen may drive clonal expansion of MAIT cells with increased functional avidity, suggesting a role for specific vaccination strategies to increase the frequency and potency of MAIT cells to optimize effector function.
Publisher: American Society for Microbiology
Date: 03-2007
DOI: 10.1128/AAC.00709-06
Abstract: Klebsiella pneumoniae causes common and severe hospital- and community-acquired infections with a high incidence of multidrug resistance. The emergence and spread of β-lactamase-producing K. pneumoniae strains highlight the need to develop new therapeutic strategies. In this study, we developed antisense peptide nucleic acids (PNAs) conjugated to the (KFF) 3 K peptide and investigated whether they could mediate gene-specific antisense effects in K. pneumoniae . No outer membrane permeabilization was observed with antisense PNAs when used alone. Antisense peptide-PNAs targeted at two essential genes, gyrA and ompA , were found to be growth inhibitory at concentrations of 20 μM and 40 μM, respectively. Mismatched antisense peptide-PNAs with sequence variations of the gyrA and ompA genes when used as controls were not growth inhibitory. Bactericidal effects exerted by peptide-anti- gyrA PNA and peptide-anti- ompA PNA on cells were observed within 6 h of treatment. The antisense peptide-PNAs specifically inhibited expression of DNA gyrase subunit A and OmpA from the respective targeted genes in a dose-dependent manner. Both antisense peptide-PNAs cured IMR90 cell cultures that were infected with K. pneumoniae (10 4 CFU) in a dose-dependent manner without any noticeable toxicity to the human cells.
Publisher: Springer Science and Business Media LLC
Date: 12-03-2019
DOI: 10.1038/S41590-019-0357-6
Abstract: In the version of this article initially published, the first affiliation lacked 'MRC' the correct name of the institution is 'MRC Weatherall Institute of Molecular Medicine'. Two designations (SP110Y and ST110H) were incorrect in the legend to Fig. 6f,h,i. The correct text is as follows: for panel f, "...loaded with either the CdtB(105-125)SP110Y (DRB4*SP110Y) or the CdtB(105-125)ST110H (DRB4*ST110H) peptide variants..." for panel h, "...decorated by the DRB4*SP110Y tetramer (lower-right quadrant), the DRB4*ST110H (upper-left quadrant)..." and for panel i, "...stained ex vivo with DRB4*SP110Y, DRB4*ST110H...". In Fig. 8e, the final six residues (LTEAFF) of the sequence in the far right column of the third row of the table were missing the correct sequence is 'CASSYRRTPPLTEAFF'. In the legend to Fig. 8d, a designation (HLyE) was incorrect the correct text is as follows: "(HlyE?)." Portions of the Acknowledgements section were incorrect the correct text is as follows: "This work was supported by the UK Medical Research Council (MRC) (MR/K021222/1) (G.N., M.A.G., A.S., V.C., A.J.P.),...the Oxford Biomedical Research Centre (A.J.P., V.C.),...and core funding from the Singapore Immunology Network (SIgN) (E.W.N.) and the SIgN immunomonitoring platform (E.W.N.)." Finally, a parenthetical element was phrased incorrectly in the final paragraph of the Methods subsection "T cell cloning and live fluorescence barcoding" the correct phrasing is as follows: "...(which in all cases included HlyE, CdtB, Ty21a, Quailes, NVGH308, and LT2 strains and in volunteers T5 and T6 included PhoN)...". Also, in Figs. 3c and 4a, the right outlines of the plots were not visible in the legend to Fig. 3, panel letter 'f' was not bold and in Fig. 8f, 'ND' should be aligned directly beneath DRB4 in the key and 'ND' should be removed from the diagram at right, and the legend should be revised accordingly as follows: "...colors indicate the HLA class II restriction (gray indicates clones for which restriction was not determined (ND)). Clonotypes are grouped on the basis of pathogen selectivity (continuous line), protein specificity (dashed line) and epitope specificity for ten HlyE-specific clones (pixilated squares), the epitope specificity was not determined...". The errors have been corrected in the HTML and PDF versions of the article.
Publisher: Wiley
Date: 02-2006
Abstract: Klebsiella pneumoniae is an opportunistic pathogen which causes pneumoniae, urinary tract infections and septicemia in immunocompromised patients. Hospital outbreaks of multidrug-resistant K. pneumoniae, especially those in neonatal wards, are often caused by strains producing the extended-spectrum-beta-lactamases (ESBLs). An immunoproteome based approach was developed to identify candidate antigens of K. pneumoniae for vaccine development. Sera from patients with acute K. pneumoniae infections (n = 55) and a control group of sera from healthy in iduals (n = 15) were analyzed for reactivity by Western blot against ESBL K. pneumoniae outer membrane proteins separated by 2-DE. Twenty highly immunogenic protein spots were identified by immunoproteomic analysis. The immunogenic proteins that are most frequently recognized by positive K. pneumoniae sera were OmpA, OmpK36, FepA, OmpK17, OmpW, Colicin I receptor protein and three novel proteins. Two of the vaccine candidate genes, OmpA (Struve et al. Microbiology 2003, 149, 167-176) and FepA (Lai, Y. C. et al.. Infect Immun 2001, 69, 7140-7145), have recently been shown to be essential in colonization and infection in an in vivo mouse model. Hence, these two immunogenic proteins could serve as potential vaccine candidates.
Publisher: Springer Science and Business Media LLC
Date: 20-06-2018
DOI: 10.1038/S41590-018-0133-Z
Abstract: To tackle the complexity of cross-reactive and pathogen-specific T cell responses against related Salmonella serovars, we used mass cytometry, unbiased single-cell cloning, live fluorescence barcoding, and T cell-receptor sequencing to reconstruct the Salmonella-specific repertoire of circulating effector CD4
Publisher: Elsevier BV
Date: 12-2005
DOI: 10.1016/J.MCP.2005.07.005
Abstract: A PCR-enzyme-linked immunosorbent assay (PCR-ELISA) was developed for direct identification of Pseudomonas aeruginosa from positive BACTEC blood culture bottles. PCR primers were designed to target a 249 bp sequence of the oprI gene in P. aeruginosa. Biotin-labeled probe (PA3) targeted to the species-specific motif were hybridized to the digoxigenin-labeled lified products from P. aeruginosa and captured on streptavidin-coated microtiter plates. The specificity of the assay using the PA3 probe was investigated with a range of microorganisms, which are commonly isolated from blood culture bottles serving as negative controls. The PCR-ELISA assay was shown to be highly specific for the identification of P. aeruginosa and was 10-fold more sensitive than an agarose gel-based detection method using the same pair of primers, with a detection limit at 10 fg of template. The PCR-ELISA assay developed in this study is 100% sensitive and 100% specific as it correctly identified all 73 positive and 42 negative controls as well as 25 double blind clinical s les. It significantly reduces the time needed for the identification of P. aeruginosa from positive BACTEC blood cultures bottles from 2-3 days to 6-8h.
Publisher: American Society for Microbiology
Date: 2011
DOI: 10.1128/CVI.00275-10
Abstract: The immunogenicity of DNA vaccines expressing outer membrane proteins as antigens was evaluated in this study. DNA vaccines consisting of vector pVAX1 expressing either outer membrane protein A or OmpK36 were injected into mice by either the intradermal or the intramuscular route. Antibodies elicited were shown to be specifically reactive to OmpA and OmpK36 by immunoblotting. The immunoglobulin G (IgG) antibodies elicited by both vaccines included IgG1, IgG2a, IgG2b, and IgG3. Immunized mice exhibited a predominance of IgG1 over IgG2a, therefore indicating a stronger humoral response. Mice receiving either of the DNA vaccines produced high levels of interleukin-12 (IL-12) and IL-10 and low levels of gamma interferon, suggesting the induction of a mixed Th1 and Th2 response. Sera from DNA vaccine-immunized mice had significantly higher opsonic activity in opsonophagocytic assays than did sera from the control mice. The level of protection afforded by pOmpK36 DNA injected intradermally into mice was the highest. These results suggest that both OmpA and OmpK36 are excellent candidates for use in future studies of vaccination against infections caused by Klebsiella pneumoniae . This is the first study which established the efficacy of protection afforded by DNA vaccines based on outer membrane proteins against K. pneumoniae infections.
Publisher: Elsevier BV
Date: 03-2022
Publisher: Elsevier BV
Date: 05-2018
Publisher: Springer Science and Business Media LLC
Date: 12-2021
DOI: 10.1038/S41590-021-01084-Z
Abstract: NP 105–113 -B*07:02-specific CD8 + T cell responses are considered among the most dominant in SARS-CoV-2-infected in iduals. We found strong association of this response with mild disease. Analysis of NP 105–113 -B*07:02-specific T cell clones and single-cell sequencing were performed concurrently, with functional avidity and antiviral efficacy assessed using an in vitro SARS-CoV-2 infection system, and were correlated with T cell receptor usage, transcriptome signature and disease severity (acute n = 77, convalescent n = 52). We demonstrated a beneficial association of NP 105–113 -B*07:02-specific T cells in COVID-19 disease progression, linked with expansion of T cell precursors, high functional avidity and antiviral effector function. Broad immune memory pools were narrowed postinfection but NP 105–113 -B*07:02-specific T cells were maintained 6 months after infection with preserved antiviral efficacy to the SARS-CoV-2 Victoria strain, as well as Alpha, Beta, Gamma and Delta variants. Our data show that NP 105–113 -B*07:02-specific T cell responses associate with mild disease and high antiviral efficacy, pointing to inclusion for future vaccine design.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Kurupati Prathiba.