Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The gal locus from Haemophilus influenzae was cloned and sequenced. Four genes were identified by amino acid homology: galT, galK, galM and galR. The coding direction of galT, galK and galM is divergent from that of galR. There are non-coding intergenic regions between galR and galT, galT nd galK, and galK and galM. Deletion-insertion mutations constructed in galK and galE, which is in lic3, were moved into the H. influenzae chromosome generating each of the single mutants as well as the double gal mutant. Even when grown on complex media, the double mutant failed to react with an anti-lipopolysaccharide monoclonal antibody known to react with a digalactoside epitope. Both the galE single and the galE galK double mutants were serum-sensitive and relatively avirulent in infant rats, indicating a critical role for galactose metabolism, and providing evidence to support a central role for lipopolysaccharide, in H. influenzae virulence.
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PMID:The gal locus from Haemophilus influenzae: cloning, sequencing and the use of gal mutants to study lipopolysaccharide. 128 42

Chimpanzee secretory immunoglobulin A (SIgA) was separated into two fractions by chromatography using the terminal galactose-binding lectin Jacalin. The SIgA fraction bound by Jacalin was cleaved by Haemophilus influenzae IgA1 protease, whereas the SIgA nonbinding fraction was not cleaved. It is proposed that these fractions represent IgA1 and IgA2 subclasses because the presence or absence of galactose-terminal oligosaccharides (Jacalin binding) and susceptibility or resistance to IgA1 protease are properties that define human IgA1 and IgA2 subclasses.
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PMID:Identification of two subclasses of IgA in the chimpanzee (Pan troglodytes). 140 36

Several chromosomal loci are involved in lipopolysaccharide (LPS) biosynthesis by Haemophilus influenzae. Two of these, lic1 and lic2, contain multiple open-reading frames (ORFs) and include tandem repeats of the tetramer CAAT within and at the 5' end of the coding region of the first ORF in each locus. Variation in the number of repeats of CAAT is involved in the variable expression of LPS epitopes, and genes within these loci are involved in the biosynthesis of these epitopes. lic3 also contains multiple ORFs and the CAAT repeats in the same arrangement as in the other two lic loci. However, in lic3 metabolic functions are encoded by the downstream genes. ORF2 is galE, encoding uridine 5'-diphosphogalactose 4-epimerase, and ORF4 is adk, encoding adenylate kinase. A mutant H. influenzae with a deleted galE gene had an altered LPS when grown on media lacking galactose and was of reduced virulence in infant rats.
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PMID:Molecular biology of phase-variable lipopolysaccharide biosynthesis by Haemophilus influenzae. 158 88

A high rate of phenotypic variation in the lipooligosaccharide (LOS) electrophoretic profile of Haemophilus somnus occurred in most isolates obtained at approximately weekly intervals from three calves intrabronchially challenged with a cloned isolate of H. somnus 2336. Daily subculturing for 2 weeks resulted in at least one major alteration in the LOS electrophoretic profiles for strain 2336 and both additional disease isolates examined, but no change occurred in the LOS electrophoretic profiles for any of three commensal isolates examined. None of the LOSs from any of the postchallenge intrabronchial isolates reacted with rabbit antiserum to the challenge strain LOS in immunoblotting, but LOSs from two nasopharyngeal isolates did. Antigenic variation in the extracted LOSs of most of the isolates was supported by the results of an enzyme-linked immunosorbent assay. Preimmune serum from each of the calves did not react with any of the isolates or the challenge strain, whereas sera obtained 35 days after challenge reacted with the challenge strain and zero to five additional isolates and sera obtained 74 days after challenge reacted with two to six additional isolates. Recognition of LOSs from isolates obtained near the end of the 70-day experiment by day-74 sera was related to clearance of the bacteria from the lungs. Isolates demonstrating major electrophoretic changes showed variations in the composition of the oligosaccharide, but not lipid A, moiety of their LOSs. The oligosaccharide of the LOS of each isolate was composed predominantly of glucose but varied substantially in the contents of galactose, arabinose, xylose, mannose, and 3-deoxy-D-manno-octulosonic acid. Therefore, the LOS of H. somnus is capable of undergoing compositional and antigenic variations, which may act as an important virulence mechanism for evading host immune defense mechanisms.
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PMID:Phenotypic phase variation in Haemophilus somnus lipooligosaccharide during bovine pneumonia and after in vitro passage. 161 61

Nontypeable Haemophilus influenzae M37 adheres to human buccal epithelial cells and exhibits mannose-resistant hemagglutination of human erythrocytes. An isogenic variant of this strain which was deficient in hemagglutination was isolated. A protein with an apparent molecular weight of 22,000 was present in the sodium dodecyl sulfate-polyacrylamide gel profile of sarcosyl-insoluble proteins from the hemagglutination-proficient strain but was absent from the profile of the isogenic hemagglutination-deficient variant. A monoclonal antibody which reacts with the hemagglutination-proficient isolate but not with the hemagglutination-deficient isolate has been characterized. This monoclonal antibody was employed in an affinity column for purification of the protein as well as to screen a genomic library for recombinant clones expressing the gene. Several clones which contained overlapping genomic fragments were identified by reaction with the monoclonal antibody. The gene for the 22-kDa protein was subcloned and sequenced. The gene for the type b pilin from H. influenzae type b strain MinnA was also cloned and sequenced. The DNA sequence of the strain MinnA gene was identical to that reported previously for two other type b strains. The DNA sequence of the strain M37 gene is 77% identical to that of the type b pilin gene, and the derived amino acid sequence is 68% identical to that of the type b pilin.
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PMID:Molecular cloning, expression, and sequence of the pilin gene from nontypeable Haemophilus influenzae M37. 167 47

Monoclonal antibodies raised against Haemophilus influenzae and Neisseria gonorrhoeae were used to investigate similarities or differences in the lipopolysaccharide antigens of pathogenic and commensal strains of several Gram-negative bacteria indigenous to mucosal surfaces of humans. In immunoblotting experiments, 20 of 36 monoclonal antibodies showed cross-reactions between species of Neisseria and Haemophilus. The common epitopes were present on N. gonorrhoeae, N. meningitidis, N. lactamica, H. influenzae including biogroup aegyptius, and occasionally H. parainfluenzae. No other commensal Neisseria or Gram-negative organisms tested reacted with the monoclonal antibodies with one exception; a single strain of pathogenic Escherichia coli was recognised by a N. gonorrhoeae-specific monoclonal antibody. One monoclonal antibody, raised against N. gonorrhoeae lipopolysaccharide, reacted with N. gonorrhoeae (32 of 59 strains), N. meningitidis (9 of 26 strains), H. influenzae (6 of 16 strains). An epitope expressed by H. influenzae and implicated in its virulence was also present on 14 of 59 strains of N. gonorrhoeae and was shown to comprise a digalactoside structure, alpha-galactosyl-1,4-beta-galactose (Gal alpha 1,4Gal beta), also found on human cells.
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PMID:Antigenic similarities in lipopolysaccharides of Haemophilus and Neisseria and expression of a digalactoside structure also present on human cells. 171 Nov 42

Twelve human isolates exhibiting the properties of the family Pasteurellaceae but phenotypically deviating from established species, or resembling species of animal origin that are only rarely reported to occur in human materials, were checked for their identities by DNA-DNA hybridization. The collection consisted of one strain of Actinobacillus lignieresii, two strains of Actinobacillus hominis (mannose-positive), two hitherto undescribed Actinobacillus or Actinobacillus-like species, [Pasteurella] haemolytica biovar T, CDC group HB-5 (initially oxidase and indole-negative), a new species in the [Haemophilus] aphrophilus [Haemophilus] segnis group, a new sucrose-negative and gas-producing Pasteurella-like species, and three strains of Bisgaard's Pasteurella-like taxon 16. Some diagnostically useful features of these unusual human Pasteurellaceae are described.
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PMID:Some unusual members of the family Pasteurellaceae isolated from human sources--phenotypic features and genomic relationships. 193 May 71

A chromosomal locus, lic3, one of several involved in lipopolysaccharide (LPS) biosynthesis by Haemophilus influenzae, was cloned and its DNA sequence determined. lic3 comprises four closely apposed open reading frames (ORFs). ORF1 includes tandem repeats of the tetramer CAAT and two start codons out of frame with each other are found upstream of the repeats. ORF1 encodes a protein with no known homologues. ORF2 encodes the UDP-galactose-4-epimerase (galE) gene. ORF3 encodes a hydrophobic protein with no known homologues. ORF4 encodes the adenylate kinase (adk) gene. A deletion/insertion mutation lacking the 3' end of ORF1, all of galE, and the 5' end of ORF3 was constructed in the parent Hib strain (RM7004). These mutants had a galE phenotype, as evidenced by galactose sensitivity, altered LPS when grown in the absence of exogenous galactose, and reduced virulence in infant rats.
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PMID:Molecular analysis of a complex locus from Haemophilus influenzae involved in phase-variable lipopolysaccharide biosynthesis. 195 82

The sugar composition and the electrophoretic mobility in SDS-polyacrylamide gel electrophoresis of the various lipopolysaccharides (LPS) from clinical isolates of Haemophilus influenzae type b (Hib) were determined to correlate epidemiologic data with compositional data. Rabbit sera specific in Ouchterlony immunodiffusion for 10 different LPS (LPS 1-10) reacted with 647 or 690 Hib strains isolated from patients with invasive disease in various continents. Serotype 1 was predominant and was found in 550 isolates (80%). None of the Hib isolates reacted with antisera specific for LPS of two nonencapsulated isolates (LPS 5 and 6). Sugar analysis by gas-liquid chromatography of trimethylsilylated methyl glycosides revealed that the LPS of the 10 serotypes contained glucose, galactose, L-glycero-D-mannoheptose, and glucosamine in various proportions. LPS 1, 2, 8, and 9 contained the highest amounts of glucose and galactose relative to L-glycero-D-mannoheptose, which is considered present in constant amounts in H. influenzae LPS. LPS 1, 2, and 9 were most frequently found in invasive disease isolates.
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PMID:Biochemical characterization and worldwide distribution of serologically distinct lipopolysaccharides of Haemophilus influenzae type b. 211 26

The taxonomic distinction between Actinobacillus (Haemophilus) actinomycetemcomitans and Haemophilus aphrophilus and the taxonomic distinction between H. aphrophilus and Haemophilus paraphrophilus have been questioned. This study was done to determine whether multivariate statistical analyses of carbohydrate data from lipopolysaccharides could be used to distinguish between these closely related species. Lipopolysaccharides were extracted with phenol-water and purified. Carbohydrates were assessed by using gas chromatography and gas chromatography-mass spectrometry after methanolysis and derivatization with trifluoroacetic acid anhydride. The lipopolysaccharides from all of the species contained rhamnose, fucose, galactose, glucose, L-glycero-D-mannoheptose, and glucosamine plus galactosamine, but in varying amounts. A. actinomycetemcomitans and H. paraphrophilus also contained D-glycero-D-mannoheptose, while H. aphrophilus did not. Sample- and variable-oriented principal-component analyses of the carbohydrate data clearly distinguished among A. actinomycetemcomitans, H. aphrophilus, and H. paraphrophilus. Soft independent modelling of class analogy showed that no sample in the A. actinomycetemcomitans class fell within the 95% confidence limits of the H. aphrophilus class. H. paraphrophilus fell outside both classes.
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PMID:Multivariate analyses of carbohydrate data from lipopolysaccharides of Actinobacillus (Haemophilus) actinomycetemcomitans, Haemophilus aphrophilus, and Haemophilus paraphrophilus. 227 55


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