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Fulltext Depolymerisation of the Klebsiella pneumoniae Capsular Polysaccharide K21 by Klebsiella Phage K5

Lukianova AA, Shneider MM, Evseev PV, Egorov MV, Kasimova AA, Shpirt AM, et al.

Int J Mol Sci, 2023 Dec 09;24(24).
PMID: 38139119 DOI: 10.3390/ijms242417288

Klebsiella pneumoniae is a pathogen associated with various infection types, which often exhibits multiple antibiotic resistance. Phages, or bacterial viruses, have an ability to specifically target and destroy K. pneumoniae, offering a potential means of combatting multidrug-resistant infections. Phage enzymes are another promising therapeutic agent that can break down bacterial capsular polysaccharide, which shields K. pneumoniae from the immune response and external factors. In this study, Klebsiella phage K5 was isolated; this phage is active against Klebsiella pneumoniae with the capsular type K21. It was demonstrated that the phage can effectively lyse the host culture. The adsorption apparatus of the phage has revealed two receptor-binding proteins (RBPs) with predicted polysaccharide depolymerising activity. A recombinant form of both RBPs was obtained and experiments showed that one of them depolymerised the capsular polysaccharide K21. The structure of this polysaccharide and its degradation fragments were analysed. The second receptor-binding protein showed no activity on capsular polysaccharide of any of the 31 capsule types tested, so the substrate for this enzyme remains to be determined in the future. Klebsiella phage K5 may be considered a useful agent against Klebsiella infections.

Matched MeSH terms: Klebsiella pneumoniae/metabolism
Fulltext Short chain N-acylhomoserine lactone production by clinical multidrug resistant Klebsiella pneumoniae strain CSG20

Ngeow YF, Cheng HJ, Chen JW, Yin WF, Chan KG

Sensors (Basel), 2013;13(11):15242-51.
PMID: 24284772 DOI: 10.3390/s131115242

Klebsiella pneumoniae is one of the most common Gram-negative bacterial pathogens in clinical practice. It is associated with a wide range of disorders, ranging from superficial skin and soft tissue infections to potentially fatal sepsis in the lungs and blood stream. Quorum sensing, or bacterial cell-cell communication, refers to population density-dependent gene expression modulation. Quorum sensing in Proteobacteria relies on the production and sensing of signaling molecules which are mostly N-acylhomoserine lactones. Here, we report the identification of a multidrug resistant clinical isolate, K. pneumoniae strain CSG20, using matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry. We further confirmed quorum sensing activity in this strain with the use of high resolution tandem liquid chromatography quadrupole mass spectrometry and provided evidence K. pneumoniae strain CSG20 produced N-hexanoyl-homoserine lactone (C6-HSL). To the best of our knowledge, this is the first report on the production of N-hexanoylhomoserine lactone (C6-HSL) in clinical isolate K. pneumoniae.

Matched MeSH terms: Klebsiella pneumoniae/metabolism*
Fulltext Proof-of-concept for incorporating mechanistic insights from multi-omics analyses of polymyxin B in combination with chloramphenicol against Klebsiella pneumoniae

Hanafin PO, Abdul Rahim N, Sharma R, Cess CG, Finley SD, Bergen PJ, et al.

CPT Pharmacometrics Syst Pharmacol, 2023 Mar;12(3):387-400.
PMID: 36661181 DOI: 10.1002/psp4.12923

Carbapenemase-resistant Klebsiella pneumoniae (KP) resistant to multiple antibiotic classes necessitates optimized combination therapy. Our objective is to build a workflow leveraging omics and bacterial count data to identify antibiotic mechanisms that can be used to design and optimize combination regimens. For pharmacodynamic (PD) analysis, previously published static time-kill studies (J Antimicrob Chemother 70, 2015, 2589) were used with polymyxin B (PMB) and chloramphenicol (CHL) mono and combination therapy against three KP clinical isolates over 24 h. A mechanism-based model (MBM) was developed using time-kill data in S-ADAPT describing PMB-CHL PD activity against each isolate. Previously published results of PMB (1 mg/L continuous infusion) and CHL (Cmax : 8 mg/L; bolus q6h) mono and combination regimens were evaluated using an in vitro one-compartment dynamic infection model against a KP clinical isolate (108 CFU/ml inoculum) over 24 h to obtain bacterial samples for multi-omics analyses. The differentially expressed genes and metabolites in these bacterial samples served as input to develop a partial least squares regression (PLSR) in R that links PD responses with the multi-omics responses via a multi-omics pathway analysis. PMB efficacy was increased when combined with CHL, and the MBM described the observed PD well for all strains. The PLSR consisted of 29 omics inputs and predicted MBM PD response (R2 = 0.946). Our analysis found that CHL downregulated metabolites and genes pertinent to lipid A, hence limiting the emergence of PMB resistance. Our workflow linked insights from analysis of multi-omics data with MBM to identify biological mechanisms explaining observed PD activity in combination therapy.

Matched MeSH terms: Klebsiella pneumoniae/metabolism
Fulltext Revealing the functionality of hypothetical protein KPN00728 from Klebsiella pneumoniae MGH78578: molecular dynamics simulation approaches

Choi SB, Normi YM, Wahab HA

BMC Bioinformatics, 2011;12 Suppl 13:S11.
PMID: 22372825 DOI: 10.1186/1471-2105-12-S13-S11

Previously, the hypothetical protein, KPN00728 from Klebsiella pneumoniae MGH78578 was the Succinate dehydrogenase (SDH) chain C subunit via structural prediction and molecular docking simulation studies. However, due to limitation in docking simulation, an in-depth understanding of how SDH interaction occurs across the transmembrane of mitochondria could not be provided.

Matched MeSH terms: Klebsiella pneumoniae/metabolism
The Role of Peganum harmala Ethanolic Extract and Type II Toxin Antitoxin System in Biofilm Formation

Valizadeh N, Valian F, Sadeghifard N, Karami S, Pakzad I, Kazemian H, et al.

Drug Res (Stuttg), 2017 Jul;67(7):385-387.
PMID: 28320039 DOI: 10.1055/s-0043-102060

Toxin antitoxin system is a regulatory system that antitoxin inhibits the toxin. We aimed to determine the role of TA loci in biofilm formation in K. pneumoniae clinical and environmental isolates; also inhibition of biofilm formation by Peganum harmala. So, 40 K. pneumoniae clinical and environmental isolates were subjected for PCR to determine the frequency of mazEF, relEB, and mqsRA TA loci. Biofilm formation assay subjected for all isolates. Then, P. harmala was tested against positive biofilm formation strains. Our results demonstrated that relBE TA loci were dominant TA loci; whereas mqsRA TA loci were negative in all isolates. The most environmental isolates showed weak and no biofilm formation while strong and moderate biofilm formation observed in clinical isolates. Biofilm formations by K. pneumoniae in 9 ug/ml concentration were inhibited by P. harmala. In vivo study suggested to be performed to introduce Peganum harmala as anti-biofilm formation in K. pneumoniae.

Matched MeSH terms: Klebsiella pneumoniae/metabolism*
Fulltext MgrB Mutations and Altered Cell Permeability in Colistin Resistance in Klebsiella pneumoniae

Yap PS, Cheng WH, Chang SK, Lim SE, Lai KS

Cells, 2022 Sep 26;11(19).
PMID: 36230959 DOI: 10.3390/cells11192995

There has been a resurgence in the clinical use of polymyxin antibiotics such as colistin due to the limited treatment options for infections caused by carbapenem-resistant Enterobacterales (CRE). However, this last-resort antibiotic is currently confronted with challenges which include the emergence of chromosomal and plasmid-borne colistin resistance. Colistin resistance in Klebsiella pneumoniae is commonly caused by the mutations in the chromosomal gene mgrB. MgrB spans the inner membrane and negatively regulates PhoP phosphorylation, which is essential for bacterial outer membrane lipid biosynthesis. The present review intends to draw attention to the role of mgrB chromosomal mutations in membrane permeability in K. pneumoniae that confer colistin resistance. With growing concern regarding the global emergence of colistin resistance, deciphering physical changes of the resistant membrane mediated by mgrB inactivation may provide new insights for the discovery of novel antimicrobials that are highly effective at membrane penetration, in addition to finding out how this can help in alleviating the resistance situation.

Matched MeSH terms: Klebsiella pneumoniae/metabolism
Fulltext N-acyl homoserine lactone production by Klebsiella pneumoniae isolated from human tongue surface

Yin WF, Purmal K, Chin S, Chan XY, Koh CL, Sam CK, et al.

Sensors (Basel), 2012;12(3):3472-83.
PMID: 22737019 DOI: 10.3390/s120303472

Bacteria communicate by producing quorum sensing molecules called autoinducers, which include autoinducer-1, an N-hexanoyl homoserine lactone (AHL), and autoinducer-2. Bacteria present in the human oral cavity have been shown to produce autoinducer-2, but not AHL. Here, we report the isolation of two AHL-producing Klebsiella pneumoniae strains from the posterior dorsal surface of the tongue of a healthy individual. Spent culture supernatant extracts from K. pneumoniae activated the biosensors Agrobacterium tumefaciens NTL4(pZLR4) and Escherichia coli [pSB401], suggesting the presence of both long and short chain AHLs. High resolution mass spectrometry analyses of these extracts confirmed that both K. pneumoniae isolates produced N-octanoylhomoserine lactone and N-3-dodecanoyl-L-homoserine lactone. To the best of our knowledge, this is the first report of the isolation of K. pneumoniae from the posterior dorsal surface of the human tongue and the production of these AHLs by this bacterium.

Matched MeSH terms: Klebsiella pneumoniae/metabolism
Envelope proteome changes driven by RamA overproduction in Klebsiella pneumoniae that enhance acquired β-lactam resistance

Jiménez-Castellanos JC, Wan Nur Ismah WAK, Takebayashi Y, Findlay J, Schneiders T, Heesom KJ, et al.

J Antimicrob Chemother, 2018 Jan 01;73(1):88-94.
PMID: 29029194 DOI: 10.1093/jac/dkx345

Objectives: In Klebsiella pneumoniae, overproduction of RamA results in reduced envelope permeability and reduced antimicrobial susceptibility but clinically relevant resistance is rarely observed. Here we have tested whether RamA overproduction can enhance acquired β-lactam resistance mechanisms in K. pneumoniae and have defined the envelope protein abundance changes upon RamA overproduction during growth in low and high osmolarity media.
Methods: Envelope permeability was estimated using a fluorescent dye accumulation assay. β-Lactam susceptibility was measured using disc testing. Total envelope protein production was quantified using LC-MS/MS proteomics and transcript levels were quantified using real-time RT-PCR.
Results: RamA overproduction enhanced β-lactamase-mediated β-lactam resistance, in some cases dramatically, without altering β-lactamase production. It increased production of efflux pumps and decreased OmpK35 porin production, though micF overexpression showed that OmpK35 reduction has little impact on envelope permeability. A survey of K. pneumoniae bloodstream isolates revealed ramA hyperexpression in 3 of 4 carbapenemase producers, 1 of 21 CTX-M producers and 2 of 19 strains not carrying CTX-M or carbapenemases.
Conclusions: Whilst RamA is not a key mediator of antibiotic resistance in K. pneumoniae on its own, it is potentially important for enhancing the spectrum of acquired β-lactamase-mediated β-lactam resistance. LC-MS/MS proteomics analysis has revealed that this enhancement is achieved predominantly through activation of efflux pump production.

Matched MeSH terms: Klebsiella pneumoniae/metabolism*
Interaction of LysM BON family protein domain with carbapenems: A putative mechanism of carbapenem resistance

Ali A, Kumar R, Khan A, Khan AU

Int J Biol Macromol, 2020 Oct 01;160:212-223.
PMID: 32464197 DOI: 10.1016/j.ijbiomac.2020.05.172

Carbapenem resistance in Gram-negative pathogens has become a global concern for health workers worldwide. In one of our earlier studies, a Klebsiella pneumoniae-carbapenemase-2 producing strain was induced with meropenem to explore differentially expressed proteins under induced and uninduced conditions. There is, LysM domain BON family protein, was found over 12-fold expressed under the induced state. A hypothesis was proposed that LysM domain protein might have an affinity towards carbapenem antibiotics making them unavailable to bind with their target. Hence, we initiated a study to understand the binding mode of carbapenem with LysM domain protein. MICs of imipenem and meropenem against LysM clone were increased by several folds as compared to NP-6 clinical strain as well as DH5 α (PET-28a KPC-2) clone. This study further revealed a strong binding of both antibiotics to LysM domain protein. Molecular simulation studies of LysM domain protein with meropenem and imipenem for 80 ns has also showed stable structure. We concluded that overexpressed LysM domain under induced condition interacted with carbapenems, leading to enhanced resistance as proved by high MIC values. Hence, the study proved the proposed hypothesis that the LysM domain plays a significant role in the putative mechanism of antibiotics resistance.

Matched MeSH terms: Klebsiella pneumoniae/metabolism
Purple urine with shock

Seak CJ, Lim MWX, Seak JC, Goh ZNL, Seak CK

QJM, 2020 06 01;113(6):434-435.
PMID: 31816086 DOI: 10.1093/qjmed/hcz314
Matched MeSH terms: Klebsiella pneumoniae/metabolism
Fulltext Novel Polymyxin Combination with the Antiretroviral Zidovudine Exerts Synergistic Killing against NDM-Producing Multidrug-Resistant Klebsiella pneumoniae

Lin YW, Abdul Rahim N, Zhao J, Han ML, Yu HH, Wickremasinghe H, et al.

Antimicrob Agents Chemother, 2019 04;63(4).
PMID: 30670431 DOI: 10.1128/AAC.02176-18

Polymyxins are used as a last-line therapy against multidrug-resistant (MDR) New Delhi metallo-β-lactamase (NDM)-producing Klebsiella pneumoniae However, polymyxin resistance can emerge with monotherapy; therefore, novel strategies are urgently needed to minimize the resistance and maintain their clinical utility. This study aimed to investigate the pharmacodynamics of polymyxin B in combination with the antiretroviral drug zidovudine against K. pneumoniae Three isolates were evaluated in static time-kill studies (0 to 64 mg/liter) over 48 h. An in vitro one-compartment pharmacokinetic/pharmacodynamic (PK/PD) model (IVM) was used to simulate humanized dosage regimens of polymyxin B (4 mg/liter as continuous infusion) and zidovudine (as bolus dose thrice daily to achieve maximum concentration of drug in broth [Cmax] of 6 mg/liter) against K. pneumoniae BM1 over 72 h. The antimicrobial synergy of the combination was further evaluated in a murine thigh infection model against K. pneumoniae 02. In the static time-kill studies, polymyxin B monotherapy produced rapid and extensive killing against all three isolates followed by extensive regrowth, whereas zidovudine produced modest killing followed by significant regrowth at 24 h. Polymyxin B in combination with zidovudine significantly enhanced the antimicrobial activity (≥4 log10 CFU/ml) and minimized bacterial regrowth. In the IVM, the combination was synergistic and the total bacterial loads were below the limit of detection for up to 72 h. In the murine thigh infection model, the bacterial burden at 24 h in the combination group was ≥3 log10 CFU/thigh lower than each monotherapy against K. pneumoniae 02. Overall, the polymyxin B-zidovudine combination demonstrates superior antimicrobial efficacy and minimized emergence of resistance to polymyxins.

Matched MeSH terms: Klebsiella pneumoniae/metabolism
Fulltext Antimicrobial activity and mode of action of 1,8-cineol against carbapenemase-producing Klebsiella pneumoniae

Moo CL, Osman MA, Yang SK, Yap WS, Ismail S, Lim SH, et al.

Sci Rep, 2021 10 21;11(1):20824.
PMID: 34675255 DOI: 10.1038/s41598-021-00249-y

Antimicrobial resistance remains one of the most challenging issues that threatens the health of people around the world. Plant-derived natural compounds have received considerable attention for their potential role to mitigate antibiotic resistance. This study was carried out to assess the antimicrobial activity and mode of action of a monoterpene, 1,8-cineol (CN) against carbapenemase-producing Klebsiella pneumoniae (KPC-KP). Results showed that resazurin microplate assay and time-kill analysis revealed bactericidal effects of CN at 28.83 mg/mL. Zeta potential showed that CN increased the surface charge of bacteria and an increase of outer membrane permeability was also detected. CN was able to cause leakage of proteins and nucleic acids in KPC-KP cells upon exposure to CN and ethidium bromide influx/efflux experiment showed the uptake of ethidium bromide into the cell; this was attributed to membrane damage. CN was also found to induce oxidative stress in CN-treated KPC-KP cells through generation of reactive oxygen species which initiated lipid peroxidation and thus damaging the bacterial cell membrane. Scanning and transmission electron microscopies further confirmed the disruption of bacterial cell membrane and loss of intracellular materials. In this study, we demonstrated that CN induced oxidative stress and membrane damage resulting in KPC-KP cell death.

Matched MeSH terms: Klebsiella pneumoniae/metabolism
Fulltext The effect of dietary bacterial organic selenium on growth performance, antioxidant capacity, and Selenoproteins gene expression in broiler chickens

Dalia AM, Loh TC, Sazili AQ, Jahromi MF, Samsudin AA

BMC Vet Res, 2017 Aug 18;13(1):254.
PMID: 28821244 DOI: 10.1186/s12917-017-1159-4

BACKGROUND: Selenium (Se) is an essential trace mineral in broilers, which has several important roles in biological processes. Organic forms of Se are more efficient than inorganic forms and can be produced biologically via Se microbial reduction. Hence, the possibility of using Se-enriched bacteria as feed supplement may provide an interesting source of organic Se, and benefit broiler antioxidant system and other biological processes. The objective of this study was to examine the impacts of inorganic Se and different bacterial organic Se sources on the performance, serum and tissues Se status, antioxidant capacity, and liver mRNA expression of selenoproteins in broilers.
RESULTS: Results indicated that different Se sources did not significantly (P ≤ 0.05) affect broiler growth performance. However, bacterial organic Se of T5 (basal diet +0.3 mg /kg feed ADS18 Se), T4 (basal diet +0.3 mg /kg feed ADS2 Se), and T3 (basal diet +0.3 mg /kg feed ADS1 Se) exhibited significantly (P ≤ 0.05) highest Se concentration in serum, liver, and kidney respectively. Dietary inorganic Se and bacterial organic Se were observed to significantly affect broiler serum ALT, AST, LDH activities and serum creatinine level. ADS18 supplemented Se of (Stenotrophomonas maltophilia) bacterial strain showed the highest GSH-Px activity with the lowest MDA content in serum, and the highest GSH-Px and catalase activity in the kidney, while bacterial Se of ADS2 (Klebsiella pneumoniae) resulted in a higher level of GSH-Px1 and catalase in liver. Moreover, our study showed that in comparison with sodium selenite, only ADS18 bacterial Se showed a significantly higher mRNA level in GSH-Px1, GSH-Px4, DIO1, and TXNDR1, while both ADS18 and ADS2 showed high level of mRNA of DIO2 compared to sodium selenite.
CONCLUSIONS: The supplementation of bacterial organic Se in broiler chicken, improved tissue Se deposition, antioxidant status, and selenoproteins gene expression, and can be considered as an effective alternative source of Se in broiler chickens.

Matched MeSH terms: Klebsiella pneumoniae/metabolism
Fulltext Additivity vs Synergism: Investigation of the Additive Interaction of Cinnamon Bark Oil and Meropenem in Combinatory Therapy

Yang SK, Yusoff K, Mai CW, Lim WM, Yap WS, Lim SE, et al.

Molecules, 2017 Nov 04;22(11).
PMID: 29113046 DOI: 10.3390/molecules22111733

Combinatory therapies have been commonly applied in the clinical setting to tackle multi-drug resistant bacterial infections and these have frequently proven to be effective. Specifically, combinatory therapies resulting in synergistic interactions between antibiotics and adjuvant have been the main focus due to their effectiveness, sidelining the effects of additivity, which also lowers the minimal effective dosage of either antimicrobial agent. Thus, this study was undertaken to look at the effects of additivity between essential oils and antibiotic, via the use of cinnamon bark essential oil (CBO) and meropenem as a model for additivity. Comparisons between synergistic and additive interaction of CBO were performed in terms of the ability of CBO to disrupt bacterial membrane, via zeta potential measurement, outer membrane permeability assay and scanning electron microscopy. It has been found that the additivity interaction between CBO and meropenem showed similar membrane disruption ability when compared to those synergistic combinations which was previously reported. Hence, results based on our studies strongly suggest that additive interaction acts on a par with synergistic interaction. Therefore, further investigation in additive interaction between antibiotics and adjuvant should be performed for a more in depth understanding of the mechanism and the impacts of such interaction.

Matched MeSH terms: Klebsiella pneumoniae/metabolism*
Fulltext Structure to function prediction of hypothetical protein KPN_00953 (Ycbk) from Klebsiella pneumoniae MGH 78578 highlights possible role in cell wall metabolism

Teh BA, Choi SB, Musa N, Ling FL, Cun ST, Salleh AB, et al.

BMC Struct Biol, 2014;14:7.
PMID: 24499172 DOI: 10.1186/1472-6807-14-7

Klebsiella pneumoniae plays a major role in causing nosocomial infection in immunocompromised patients. Medical inflictions by the pathogen can range from respiratory and urinary tract infections, septicemia and primarily, pneumonia. As more K. pneumoniae strains are becoming highly resistant to various antibiotics, treatment of this bacterium has been rendered more difficult. This situation, as a consequence, poses a threat to public health. Hence, identification of possible novel drug targets against this opportunistic pathogen need to be undertaken. In the complete genome sequence of K. pneumoniae MGH 78578, approximately one-fourth of the genome encodes for hypothetical proteins (HPs). Due to their low homology and relatedness to other known proteins, HPs may serve as potential, new drug targets.

Matched MeSH terms: Klebsiella pneumoniae/metabolism
Imipenem-resistance in Klebsiella pneumoniae in Malaysia due to loss of OmpK36 outer membrane protein coupled with AmpC hyperproduction

Palasubramaniam S, Karunakaran R, Gin GG, Muniandy S, Parasakthi N

Int J Infect Dis, 2007 Sep;11(5):472-4.
PMID: 17337225
Matched MeSH terms: Klebsiella pneumoniae/metabolism*
Fulltext Lavender essential oil induces oxidative stress which modifies the bacterial membrane permeability of carbapenemase producing Klebsiella pneumoniae

Yang SK, Yusoff K, Thomas W, Akseer R, Alhosani MS, Abushelaibi A, et al.

Sci Rep, 2020 01 21;10(1):819.
PMID: 31964900 DOI: 10.1038/s41598-019-55601-0

Misuse of antibiotics in the clinical and agricultural sectors has caused the emergence of multidrug-resistant (MDR) Klebsiella pneumoniae which contributes a threat to human health. In this study, we assessed the feasibility of lavender essential oil (LVO) as an antimicrobial agent in combinatory therapy with meropenem in suppressing the growth of carbapenemase-producing K. pneumoniae (KPC-KP). Synergistic interactions between LVO and meropenem were detected, which significantly reduce the inhibitory concentration of both LVO and meropenem by 15 and 4-fold respectively. Comparative proteomic profiling identified a disruption in the bacterial membrane via oxidative stress that was indicated by loss of membrane and cytoplasmic proteins and the upregulation of oxidative regulators. As a proof of concept, zeta potential measurements showed a change in cell surface charge while outer membrane permeability measurement indicated an increase in membrane permeability following exposure to LVO. This was indicative of a disrupted outer membrane. Ethidium bromide influx/efflux assays demonstrated no significant efflux pump inhibition by LVO, and scanning electron microscopy revealed irregularities on the cell surface after exposure to LVO. Oxidative stress was also detected with increased level of ROS and lipid peroxidation in LVO-treated cells. In conclusion, our data suggest that LVO induced oxidative stress in K. pneumoniae which oxidizes the outer membrane, enabling the influx of generated ROS, LVO and meropenem into the bacterial cells, causing damage to the cells and eventually death.

Matched MeSH terms: Klebsiella pneumoniae/metabolism
Fulltext Investigation on the conA binding properties of Klebsiella pneumoniae

Anuar AS, Tay ST

Trop Biomed, 2014 Dec;31(4):802-12.
PMID: 25776607 MyJurnal

Klebsiella pneumoniae is a healthcare-associated bacterial pathogen which causes severe diseases in immunocompromised individuals. Concanavalin A (conA), a lectin which recognizes proteins with mannose or glucose residues, has been reported to agglutinate K. pneumoniae and hence, is postulated to have therapeutical potential for K. pneumoniae-induced liver infection. This study investigated the conA binding properties of a large collection of clinical isolates of K. pneumoniae. ConA agglutination reaction was demonstrated by 94 (51.4%) of 183 K. pneumoniae isolates using a microtiter plate assay. The conA agglutination reactions were inhibited in the presence of 2.5 mg/ml D-mannose and 2.5 mg/ml glucose, and following pretreatment of the bacterial suspension with protease and heating at 80ºC. Majority of the positive isolates originated from respiratory specimens. Isolation of conA-binding proteins from K. pneumoniae ATCC 700603 strain was performed using conA affinity column and the conA binding property of the eluted proteins was confirmed by western blotting analysis using conA-HRP conjugates. Proteins with molecular weights ranging from 35 to 60 kDa were eluted from the conA affinity column, of which four were identified as outer membrane protein precursor A (37 kDa), outer membrane protein precursor C (40 kDa), enolase (45 kDa) and chaperonin (60 kDa) using mass spectrometry analysis. Several conA binding proteins (including 45 and 60 kDa) were found to be immunogenic when reacted with rabbit anti-Klebsiella antibody. The function and interplay of the conA binding proteins in bacterium-host cell relationship merits further investigation.

Matched MeSH terms: Klebsiella pneumoniae/metabolism*

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