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Query: UMLS:C0519030 (Klebsiella)
 21,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The adherence of bacteria to the uroepithelium is mediated partially by a lectin present on the bacterial surface and can be blocked by mannose derivatives. The presence of the bacterial lectin was sought in the urine of 170 catheterized patients. Sixty-one percent of the isolated Escherichia coli, 55% of the isolated Klebsiella sp. and 11% of the isolated Proteus sp. agglutinated yeast cells and thus had lectin on their surfaces. In most instances the agglutination could be blocked by mannose. Lectin-bearing E. coli were significantly more sensitive to cephalothin and sulfamexazole-trimethoprim than the other isolates, and they were isolated from the urine of patients who were catheterized for shorter periods of time (mean 4.0 days) and who had not received antibiotics or short antibiotic courses.
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PMID:Screening of urinary pathogens obtained from catheterized patients for mannose-specific lectin: clinical implications. 704 34

The production of a capsular polysaccharide (CPS; K antigen) is characteristic of Klebsiella pneumoniae, but CPS structure varies among strains, and many different serotypes are now known. In this study, cps gene clusters encoding the elements of capsular polysaccharide biosynthesis were exchanged by homologous recombination between strains expressing different serotypes. The wild-type K. pneumoniae strains used for genetic exchange were KPA1 (cpsK2), expressing K2 CPS, and KPB1 (cpsK21a), expressing K21a CPS. Plasmid R68.45 was used to mobilize fragments of chromosomal DNA from auxotrophic derivatives of donor strains. Auxotrophic his alleles introduced into recipient strains provided selectable markers to coinherit the adjacent cps gene clusters from donors expressing a heterologous CPS. Each of the capsule-switched recombinants, KPA5 (cpsK21a) and KPB20 (cpsK2), was shown to have a CPS that was immunologically identical to the serotype of the respective donor. The recombinants retained their respective recipient strain background, as evidenced by a genetic marker and demonstration of a distinctive restriction fragment length polymorphism in genomic DNA. KPB1 CPS contained a sequence (mannose-alpha-2-mannose) that binds to a macrophage lectin and may be responsible for their higher susceptibility to macrophage binding and phagocytosis compared with KPA1, whose CPS lacked such sequences. The recombinant strains expressing heterologous cps genes inherited the macrophage-binding phenotype of the donor, thus confirming that relative susceptibility to phagocytosis was determined by the capsule type expressed. KPA1 was highly virulent in a mouse lethality assay, which is a feature typical of K2 strains, whereas KPB1 was not virulent in mice. Recombinant KPA5 retained relatively high virulence in mice, even though it produced the heterologous K21a CPS, which suggests that a virulence factor other than capsule biosynthesis is encoded by the KPA genomic strain background. In contrast, KPB20 gained marginal virulence in the mouse lethality assay through the inheritance and expression of the K2 CPS from the virulent strain. Thus, pathogenesis in K. pneumoniae may be multifactorial. Specific antibody was used to stabilize the CPS on the surface of K. pneumoniae, and the structural organization of the homologous and heterologous capsules was examined by electron microscopy. Recombinant KPB20, expressing heterologous K2 CPS, had a uniform layer of capsule surrounding the organism that was similar to that seen on the surfaces of the parental strains. However, KPA5, expressing the heterologous K21a CPS, was unusual in that the uniform capsular layer was physically separated from the cell wall by approximately 50 nm.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Genetic exchange of determinants for capsular polysaccharide biosynthesis between Klebsiella pneumoniae strains expressing serotypes K2 and K21a. 810 96

We found unique behaviors among platelets within a few minutes of the intravenous injection of lipopolysaccharide (LPS) into mice. Platelets accumulated primarily in the liver at lower doses of LPS, but at higher doses they accumulated largely in the lungs. When the platelets accumulated in these organs were degraded, there was a rapid anaphylactoid shock. The platelet response depended on the strain of mouse and on the source of LPS. Of various LPSs tested, the LPS from the smooth type of Klebsiella O3 (KO3-S LPS) was the most potent at inducing the platelet response and shock. K-76 monocarboxylic acid, an inhibitor of complement C5, effectively prevented the KO3-S LPS-induced degradation (but not accumulation) of platelets and the ensuing rapid shock in BALB/c mice. Moreover, in DBA/2 mice (which are deficient in complement C5), platelets accumulated in the lungs and liver in response to KO3-S LPS but soon returned to the circulation without degradation, and there was no rapid shock. The LPS from the rough type of KO3 induced an accumulation of platelets in the liver and lungs but not a degradation of platelets. On the basis of these results and those reported by other investigators, we propose that in the platelet response to LPS, the lectin pathway to form C3 convertase from C4 and C2 is involved in the rapid accumulation of platelets in the liver and lungs and that the pathway from C5 to C9 is involved in the destruction of platelets and the consequent anaphylactoid shock.
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PMID:Complement-dependent accumulation and degradation of platelets in the lung and liver induced by injection of lipopolysaccharides. 1049 94

Mannose-binding lectin (MBL) is a collagenous serum lectin believed to be of importance in innate immunity. Genetically determined low levels of the protein are known to predispose to infections. In this study the binding of purified MBL to pathogens isolated from immunocompromised children was investigated by flow cytometry. Diverse Candida species, Aspergillus fumigatus, Staphylococcus aureus, and beta-hemolytic group A streptococci exhibited strong binding of MBL, whereas Escherichia coli, Klebsiella species, and Haemophilus influenzae type b were characterized by heterogeneous binding patterns. In contrast, beta-hemolytic group B streptococci, Streptococcus pneumoniae, and Staphylococcus epidermidis showed low levels of binding. Bound MBL was able to promote C4 deposition in a concentration-dependent manner. We conclude that MBL may be of importance in first-line immune defense against several important pathogens.
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PMID:Mannose-binding lectin binds to a range of clinically relevant microorganisms and promotes complement deposition. 1063 34

We previously reported that an intravenous injection of specified bacterial lipopolysaccharides (LPS) induced anaphylactoid shock in muramyldipeptide (MDP)-primed mice of various strains, including LPS-resistant C3H/HeJ, accompanied with occasional mortality of mice within 1 h. Prior to shock, rapid accumulation of blood platelets into the lungs and liver followed by degradation of the platelets and tissue destruction were observed. In this report we present the following evidence suggesting that complement activation by LPS is responsible for the anaphylactoid reaction. In C5-deficient DBA/2 mice, the platelet degradation and anaphylactoid reactions did not occur following injection of Prevotella intermedia LPS, although transient platelet accumulation into the lungs and liver was observed. Anti-complement agents K-76 COOH (C5 inhibitor) and cobra venom factor (C5 consumer) protected MDP-primed C3H/HeJ mice from mortality in the anaphylactoid reaction induced by P. intermedia and Salmonella typhimurium LPS, respectively. K-76 COOH also inhibited platelet degradation, but not accumulation, induced by P. intermedia LPS in C3H/HeN mice. LPS specimens carrying mannose-homopolymer (MHP) prepared from wild-type Klebsiella 03 and Escherichia coli 08 and 09 and recombinant E. coli 08 and 09 strains, which have been reported to markedly activate the human complement system probably through the lectin pathway, induced anaphylactoid reactions in MDP-primed C3H/HeJ mice. In contrast, LPS from R-mutant of Klebsiella 03 and the parental strain of the recombinant E. coli strains, which lacked MHP, did not induce anaphylactoid reaction. Based on these findings together with those of our previous studies, we postulated the following mechanism for the anaphylactoid reaction: strong complement activation by specified LPS preparations induced degradation of platelets which have accumulated in the lungs and liver, resulting in acute inflammation accompanied with severe tissue destruction, especially in the lungs, which in turn leads to anaphylactoid reaction. However, the mechanism of platelet accumulation induced by LPS is not yet clear.
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PMID:Complement system is involved in anaphylactoid reaction induced by lipopolysaccharides in muramyldipeptide-treated mice. 1109 92

The enterobacterium Klebsiella oxytoca strain BAS-10 was isolated from sediments under an iron mat formed in a stream receiving leached waters from pyrite mine tailings. Under anaerobic laboratory conditions, BAS-10 fermented Fe(III)-citrate and Na-citrate giving CH(3)COOH and CO(2). In the presence of ferric citrate, BAS-10 secreted quantities of a thick gel containing glucose and/or mannose, if not other sugars. Sugar residues were observed in microbial aggregates using the sugar-specific concanavalin A lectin conjugated with fluorescein and imaged by a scanning confocal laser microscope. The gel bound Fe(III) which quickly precipitated. During fermentation, however, half the initial Fe(III) concentration was reduced to Fe(II) which did not bind to the gel and remained in solution. BAS-10 showed a high tolerance to heavy metals. Its growth was not inhibited by 1 mM Zn-, Pb- or Cd-acetate. These cations also co-precipitated with the iron gel, suggesting a possible application of this strain for abatement of toxic metals under anaerobic conditions.
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PMID:Gel sequestration of heavy metals by Klebsiella oxytoca isolated from iron mat. 1145 21

A lectin isolated from the red alga Solieria filiformis was evaluated for its effect on the growth of 8 gram-negative and 3 gram-positive bacteria cultivated in liquid medium (three independent experiments/bacterium). The lectin (500 microg/mL) stimulated the growth of the gram-positive species Bacillus cereus and inhibited the growth of the gram-negative species Serratia marcescens, Salmonella typhi, Klebsiella pneumoniae, Enterobacter aerogenes, Proteus sp, and Pseudomonas aeruginosa at 1000 microg/mL but the lectin (10-1000 microg/mL) had no effect on the growth of the gram-positive bacteria Staphylococcus aureus and B. subtilis, or on the gram-negative bacteria Escherichia coli and Salmonella typhimurium. The purified lectin significantly reduced the cell density of gram-negative bacteria, although no changes in growth phases (log, exponential and of decline) were observed. It is possible that the interaction of S. filiformis lectin with the cell surface receptors of gram-negative bacteria promotes alterations in the flow of nutrients, which would explain the bacteriostatic effect. Growth stimulation of the gram-positive bacterium B. cereus was more marked in the presence of the lectin at a concentration of 1000 microg/mL. The stimulation of the growth of B. cereus was not observed when the lectin was previously incubated with mannan (125 microg/mL), its hapten. Thus, we suggest the involvement of the binding site of the lectin in this effect. The present study reports the first data on the inhibition and stimulation of pathogenic bacterial cells by marine alga lectins.
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PMID:Differential activity of a lectin from Solieria filiformis against human pathogenic bacteria. 1630 91

Interaction of bacteria with lectin using anti-lectin antibody by ELISA is an established method. In the present study, we have devised a simple ELISA using a biotinylated lectin and antibiotin-HRP. Ficus cunia agglutinin (FCA), which has shown the specificity towards alpha/beta anomers of GlcNAc and other-NAc containing sugars like LacNAc and GlcNAcbeta(1-4/6)GlcNAc, was used as a model lectin for the study of interaction with immobilized microorganisms on ELISA plate. The bacterial cells of E. coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Bacillus subtilis and Staphylococcus aureus showed binding with FCA and the degree of binding was dependent on the bacterial surface antigen. This method is considered a simple technique to study the lectin-bacteria interaction.
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PMID:Ficus cunia agglutinin for recognition of bacteria. 1695 57

Bacterium Klebsiella pneumoniae (KP) contains a prominent capsule. Clinical infections usually are associated with pneumonia or urinary tract infection (UTI). Emerging evidence implicates KP in severe liver abscess especially in diabetic patients. The goal of this study was to investigate the capsular polysaccharides from KP of liver abscess (hepatic-KP) and of UTI-KP. The composition of capsular polysaccharides was analyzed by capillary high-performance liquid chromatography (HPLC, Dionex system). The terminal sugars were assayed by binding ability to lectins. The results showed that the capsule of a hepatic KP (KpL1) from a diabetic patient contained fucose, while the capsule from UTI-KP (KpU1) did not. The absence of fucose was verified by the absence of detectable polymerase chain reaction (PCR) fragment for fucose synthesis genes, gmd and wcaG in KpU1. Mice infected with the KpL1 showed high fatality, whereas those infected with the KpU1 showed high survival rate. The KpL1 capsule was reactive to lectins AAA and AAL, which detect fucose, while the KpU1 capsule was reactive to lectin GNA, which detects mannose. Phagocytosis experiment in mouse peritoneal cavity indicated that the peritoneal macrophages could interact with KpU1, while rare association of KpL1 with macrophages was observed. This study revealed that different polysaccharides were displayed on the bacterial capsules of virulent KpL1 as compared with the less virulent KpU1. Interaction of KpU1 with mice peritoneal macrophages was more prominent than that of KpL1. The possession of fucose might contribute to KpL1 virulence by avoiding phagocytosis since fucose on bacteria had been implicated in immune evasion.
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PMID:Contribution of fucose-containing capsules in Klebsiella pneumoniae to bacterial virulence in mice. 1815 7

We tested the relationship between the capsular and the O-antigen structures and the ability of bacteria to trigger respiratory burst in human polymorphonuclear leukocytes (PMNL). Capsulated and non-capsulated variants as well as capsule-switched derivatives of Klebsiella serotypes bearing or lacking manno(rhamno)biose repeats in their capsular polysaccharides and expressing either mannose-rich or mannose-poor O antigens were tested for their ability to induce respiratory burst and survive in human PMNL. Luminol-enhanced chemiluminescence (CL) was measured to quantify respiratory burst. Intracellular survival was quantified by determining the viable counts of intracellular bacteria. K serotypes and the capsule-switched derivative lacking manno(rhamno)biose induced significantly lower CL than those expressing manno(rhamno)biose. Manno(rhamno)biose-lacking serotypes survived in the cells significantly better than serotypes expressing these repeats. C1q depletion did not affect CL induced by the manno(rhamno)biose-containing serotype, whereas factor B depletion revealed a significantly reduced CL. Likewise, EGTA in the presence of Mg(2+) significantly decreased CL, but the values were higher than those induced by the bacterium opsonized with factor B-depleted serum. In the presence of EGTA, Mg(2+)-treated factor B-depleted serum revealed a significant reduction in the CL response compared with the responses induced by opsonization with factor B-depleted serum alone. These results indicate, in addition to the alternative pathway, a manno(rhamno)biose pattern recognition of Klebsiella by PMNL probably by the complement lectin pathway.
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PMID:Manno(rhamno)biose-containing capsular polysaccharides of Klebsiella pneumoniae enhance opsono-stimulation of human polymorphonuclear leukocytes. 2037 72


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