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 mutated gene in JG16, a Haemophilus influenzae strain deficient in competence-induced DNA binding and uptake, was cloned and the wild-type allele was sequenced. The gene was shown by Northern analysis to be constitutively expressed on a 1.7-kilobase transcript. The gene product was identified as a 20.6-kDa protein targeted to the periplasm. The protein contains the sequence Cys-Pro-His-Cys (CPHC) and is highly similar to two other periplasmic CPHC motif-containing proteins: DsbA, an Escherichia coli protein (45% identity, 87% homology) and TcpG, a Vibrio cholerae protein (32% identity, 74% homology). Both DsbA and TcpG promote disulfide bond formation in periplasmic proteins, are required for pilus biogenesis, and, like thioredoxin, are capable of reducing insulin in vitro. The Haemophilus protein was shown to complement an E. coli mutation in DsbA and was named Por (periplasmic oxidoreductase). In JG16 the competence-dependent redistribution of inner membrane proteins did not occur. These findings suggest that Por is required for the correct assembly and/or folding of one or more disulfide-containing cell envelope protein involved either in competence development or in the DNA-binding and -uptake machinery.
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PMID:A periplasmic protein disulfide oxidoreductase is required for transformation of Haemophilus influenzae Rd. 143 13

Three epidemiologically unrelated clusters of Haemophilus influenzae resistant to ampicillin, chloramphenicol, and tetracycline were studied. The biotypes and cell-envelope protein patterns were determined for 17 nonencapsulated strains, 6 from Dundee and 11 from Cheltenham, and for 6 type b encapsulated strains from Guildford. After mobilization by conjugation, large 32- to 36-MDa plasmids were purified from all the strains. The restriction fragment patterns of the plasmids were determined by ethidium bromide staining of digested purified plasmid or by Southern hybridization of digested total cellular DNA of the parent strains, probed with purified plasmid. Evidence is presented for a chromosomal location of the plasmids in the parent strains, the spread in nature of a plasmid between distinguishable strains of H. influenzae, the person-to-person spread of a strain within a cluster, and a high degree of sequence homology between distinguishable plasmids, implying their close relatedness.
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PMID:Molecular epidemiology of unrelated clusters of multiresistant strains of Haemophilus influenzae. 158 25

Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis of iron-deficient and replete cell envelopes, 59Fe-siderophore uptake studies, and Western immunoblots and cytofluorimetric analyses with monoclonal antibodies (MAbs), we surveyed a panel of gram-negative bacteria to identify outer membrane proteins that are structurally related to the Escherichia coli K-12 ferric enterobactin receptor, FepA. Antibodies within the panel identified FepA epitopes that are conserved among the majority of the bacteria tested, as well as epitopes present in only a few of the strains. In general, epitopes of FepA that are buried in the outer membrane bilayer were more conserved among gram-negative bacteria than epitopes that are exposed on the bacterial cell surface. The surface topology and tertiary structure of FepA are quite similar in E. coli and Shigella flexneri but differ in Salmonella typhimurium. Of the 18 different genera tested, 94% of the bacteria transported ferric enterobactin, including members of the previously unrecognized genera Citrobacter, Edwardsiella, Enterobacter, Haemophilus, Hafnia, Morganella, Neisseria, Proteus, Providencia, Serratia, and Yersinia. The ferric enterobactin receptor contains at least one buried epitope, recognized by MAb 2 (C. K. Murphy, V. I. Kalve, and P. E. Klebba, J. Bacteriol. 172:2736-2746, 1990), that is conserved within the structure of an iron-regulated cell envelope protein in all the bacteria that we have surveyed. With MAb 2, we identified and determined the Mr of cell envelope antigens that are immunologically related to E. coli FepA in all the gram-negative bacteria tested. Collectively, the library of anti-FepA MAbs showed unique patterns of reactivity with the different bacteria, allowing identification and discrimination of species within the following gram-negative genera: Aeromonas, Citrobacter, Edwardsiella, Enterobacter, Escherichia, Haemophilus, Hafnia, Klebsiella, Morganella, Neisseria, Proteus, Providencia, Pseudomonas, Salmonella, Serratia, Shigella, Vibrio, and Yersinia.
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PMID:Evolution of the ferric enterobactin receptor in gram-negative bacteria. 171 34

From October, 1988, to January, 1989, 18 patients admitted to an acute medical chest ward were infected with an ampicillin-resistant beta-lactamase-producing strain of Haemophilus influenzae. All 18 isolates were non-encapsulated strains of biotype III and showed identical cell envelope protein profiles, as judged by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The organism was not isolated from repeated environmental samples but there was strong circumstantial evidence that a spirometer was a common iatrogenic source of the cross-infection.
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PMID:Cross-infection by non-encapsulated Haemophilus influenzae. 197 82

Twenty patients with chronic purulent rhinosinusitis were treated with TP-1 (Serono; 1 mg/kg body weight), in a double-blind cross-over trial. TP-1 was administered by daily i.m. injections for the first 14 days followed by two injections/week for 6 further weeks. The patients were immunologically special in that they had defects in their cell-mediated immune system. Fourteen showed a decreased chemotactic responsiveness of their peripheral blood monocytes as measured in the polarization assay. This defective function can probably be ascribed to the presence in serum of low molecular weight factors (LMWFs; less than 25 kD). As reported earlier, this factor shows a structural homology to the envelope protein of murine and feline leukaemia virus (P15E). Thirteen patients showed a defective delayed-type hypersensitivity (DTH) skin test reactivity towards candidin and/or streptokinase-streptodornase (Sk/Sd) antigen, 14 had a defective MIF production from their peripheral blood lymphocytes towards candidin, Sk/Sd and/or Haemophilus influenzae antigen. Eighteen patients completed the TP-1 trial and showed clinical improvements: 12 out of 15 were feeling better during TP-1 therapy and the nasal mucosa showed on inspection absent mucopurulent secretion in 13 patients. Positive bacterial culture rates for the nose decreased from 14 out of 16 to five out of 15. Placebo treatment had no significant effects. The clinical improvements were accompanied by a better performance of the cell-mediated immune system; the most significant effects were recorded in the monocyte polarization assay. The suppressive P15E-like LMWFs in serum clearly decreased during TP-1 treatment. In vitro TP-1 neutralized the immunosuppressive effect of the LMWFs. The restoring effects of TP-1 on monocyte polarization and its neutralizing activity of P15E-like LMWFs could explain the beneficial effects of thymic hormone treatment reported in adults with clinical signs of immunodeficiency in the presence of a full T cell repertoire.
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PMID:Beneficial effects of the thymic hormone preparation thymostimulin in patients with defects in cell-mediated immunity and chronic purulent rhinosinusitis. A double-blind cross-over trial on improvements in monocyte polarization and clinical effects. 219 46

The major cell envelope protein compositions of seven Actinobacillus actinomycetemcomitans strains of human origin were compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The major envelope polypeptides were homogeneous, in relation to molecular weight, in all of the strains that were examined. The characterization of the five major proteins, designated Env1 through Env5, in the leukotoxic strain Y4 revealed that proteins Env2 to -5 may reside in the outer membrane as suggested by differential detergent extractions and 125I-labeling experiments. The proteins did not demonstrate covalent or ionic interactions with the peptidoglycan; however, one protein, Env2, displayed heat-modifiable properties, having apparent molecular weights of 32,000 and 45,000 when heated in sodium dodecyl sulfate at 50 and 100 degrees C, respectively. The protein composition of the extracellular "bleb" material, normally released by strain Y4, was determined, and proteins Env1 to -4 were the predominant protein species found. A comparison of the cell envelope proteins of strain Y4 with those of other members of the human oral flora, including species within the genera Capnocytophaga, Bacteroides, and Fusobacterium, revealed distinct differences on the basis of molecular size and heat-modifiable properties. However, the membrane proteins of Haemophilus aphrophilus showed a remarkable degree of homology with those of A. actinomycetemcomitans.
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PMID:Identification and characterization of the major cell envelope proteins of oral strains of Actinobacillus actinomycetemcomitans. 640 94

Morphology, biochemical reactions, pigmentation, antigens, and cell envelope proteins were examined in 12 strains of Haemophilus somnus, Haemophilus agni, Histophilus ovis, and Actinobacillus seminis. All of the strains except A. seminis are related and are considered as a single Haemophilus-Histophilus (HH) group. In immunodiffusion tests, HH group bacteria had at least two antigens common to all members of the group, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that they have similar cell envelope protein profiles. A quantitatively variable yellow pigment with absorption maxima of 430 to 435 nm was present in strains of H. somnus and H. agni. The HH group did not produce catalase and grew only in air containing 10% CO2. Of 10 HH group bacteria, 9 required thiamine monophosphate for growth. A. seminis was distinguished from the HH group by its lack of yellow pigment, production of catalase, growth in air, lack of a thiamine monophosphate requirement, and different cell envelope protein profile. In gel immunodiffusion tests, A. seminis antigens produced two lines of partial identity with the HH group when antiserum against H. somnus was used. Reference strains of Haemophilus influenzae, Actinobacillus lignieresii, and Haemophilus haemoglobinophilus were compared with the test strains. In immunodiffusion tests, a single antigen was found to be common to H. haemoglobinophilus, A. seminis, and the HH group. No similarities between any of the test strains and H. influenzae or A. lignieresii were noted. The close relationship of H. somnus, H. agni, and Histophilus ovis suggests that these unofficially named bacteria may belong to a single taxon.
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PMID:Morphological, biochemical, antigenic, and cytochemical relationships among Haemophilus somnus, Haemophilus agni, Haemophilus haemoglobinophilus, Histophilus ovis, and Actinobacillus seminis. 640 18

A 26-kDa protein (OMP26) isolated and purified from nontypeable Haemophilus influenzae (NTHI) strain 289 has been shown to enhance clearance of infection following pulmonary challenge with NTHI in rats. DNA sequence analysis revealed that it was 99% identical to a gene encoding a cell envelope protein of the H. influenzae Rd strain (TIGR accession no. HI0916). The deduced amino acid sequence revealed a hydrophilic polypeptide rich in basic amino acids. Restriction fragment length polymorphism analysis suggested that the OMP26 gene was relatively conserved among isolates of NTHI. Analysis of the deduced amino acid sequence of the OMP26 gene from 20 different isolates showed that similarity with NTHI-289 ranged from 96.5% (1 isolate) to 99.5% (14 isolates). Two recombinant forms of OMP26, a full length 28-kDa protein (equivalent to preprotein) and a 26-kDa protein lacking a 23-amino-acid leader peptide (equivalent to processed protein), were assessed in immunization studies for the ability to induce an immune response that would be as effective as the native protein in enhancing the clearance of NTHI following pulmonary challenge in rats. Immunization with the recombinant protein that included the leader peptide was more effective in enhancing pulmonary clearance, and it induced a better cell-mediated response and higher titers of systemic and mucosal antibody. This study has characterized a 26-kDa protein from NTHI that shows significant potential as a vaccine candidate.
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PMID:Characterization of the gene encoding a 26-kilodalton protein (OMP26) from nontypeable Haemophilus influenzae and immune responses to the recombinant protein. 1008 39