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 P2 porin protein is the major outer membrane protein of nontypeable Haemophilus influenzae. Five monoclonal antibodies to P2 of four strains of nontypeable H. influenzae were developed by immunizing mice with whole bacterial cells. All five antibodies recognized epitopes on P2 in immunoblot assays of whole organism lysates, purified outer membrane, and purified P2. Competitive enzyme-linked immunosorbent assays and immunoblot assays of cyanogen bromide-digested P2 showed that two antibodies to the P2 protein of strain 1479 recognized different epitopes on the molecule. Immunofluorescence and immunoelectron microscopy demonstrated that each of the five antibodies recognized epitopes that were abundantly expressed on the bacterial surface. Analysis of 120 H. influenzae strains indicated that three of the five antibodies were reactive exclusively with the homologous strain. The remaining two antibodies were reactive with less than 3% of the strains. These studies indicate that the P2 protein expresses a highly strain-specific and immunodominant epitope on the bacterial surface. The expression of strain-specific and immunodominant epitopes on the bacterial surface may represent a mechanism by which the bacterium induces antibodies that will protect against recurrent infection by the homologous strain but will not protect against infection by heterologous strains.
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PMID:Strain-specific and immunodominant surface epitopes of the P2 porin protein of nontypeable Haemophilus influenzae. 170 17

Infections caused by Haemophilus influenzae are a major worldwide health problem. In particular, nontypeable strains of H. influenzae are a common cause of otitis media in infants and children. A vaccine to prevent these infections would result in the prevention of substantial morbidity and cost savings. A problem in identifying an appropriate vaccine antigen has been the enormous antigenic heterogeneity among nontypeable strains of H. influenzae. The present study was undertaken to characterize the conservation of the P6 outer membrane protein (approximately 16,000 daltons) among strains of H. influenzae. A total of 20 type b strains and 20 nontypeable strains of diverse geographic and clinical origins was studied. Three approaches were taken. (i) Antigenic determinants recognized by monoclonal and polyclonal antibodies were present on P6 in all 40 strains tested. The molecular weight of P6 was identical in all strains. (ii) Comparison of the DNA sequences of the P6 genes from three epidemiologically and serologically unrelated strains demonstrated 100% homology at the amino acid level and 97 to 99% homology at the nucleotide level. (iii) Restriction fragment length polymorphism analysis demonstrated that the P6 gene and flanking sequences were highly conserved among all strains. These three independent series of experiments indicated that the P6 protein is highly conserved among strains of H. influenzae. P6 should receive serious consideration for inclusion in a vaccine to prevent infections caused by nontypeable H. influenzae.
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PMID:Molecular conservation of the P6 outer membrane protein among strains of Haemophilus influenzae: analysis of antigenic determinants, gene sequences, and restriction fragment length polymorphisms. 171 97

Haemophilus parainfluenzae synthesizes an outer membrane protein adhesin which mediates binding to oral streptococci, salivary pellicle, and neuraminidase-treated erythrocytes. An indirect gold labeling technique and immunoelectron microscopy verified the location of this outer membrane protein. Further, a clustering of gold particles was observed in irregular patches at the cell surface.
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PMID:Clustering of an outer membrane adhesin of Haemophilus parainfluenzae. 173 May 5

A cloned fragment of Yersinia enterocolitica DNA complemented the defect in ferrioxamine B uptake of an Escherichia coli fhuE mutant lacking the outer membrane high-affinity transport protein FhuE. Subcloning revealed that a 13.7-kDa outer membrane protein was required for complementation. The amino acid sequence deduced from the nucleotide sequence showed extensive homology to PCPHi, an outer membrane lipoprotein of Haemophilus influenzae. We therefore termed this protein PCPYe. Plasmid-encoded pcpY mediated a low-affinity uptake of ferrioxamine B which may be caused by changes in the permeability of the outer membrane due to an overexpression of this outer membrane protein. A transposon insertion mutant in the plasmid-encoded pcpY gene was transferred into the chromosome of Y. enterocolitica. The resulting mutation had no effect on the high-affinity uptake of ferrioxamine B in Yersinia cells. Using the antibiotic ferrimycin we were able to isolate a Y. enterocolitica mutant lacking the high-affinity outer membrane receptor for ferrioxamine uptake, termed FoxA.
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PMID:A lipoprotein of Yersinia enterocolitica facilitates ferrioxamine uptake in Escherichia coli. 173 92

We performed a double-blind, randomized trial to compare the immunogenicity and reactogenicity of four conjugate Haemophilus influenzae type b vaccines given to infants 2, 4, and 6 months of age. Adverse reactions attributable to the vaccines were few and minor. The rates of systemic reactions did not differ among the various vaccines and were similar to those seen among children receiving conventional diphtheria-tetanus-pertussis vaccine. However, the four conjugate H. influenzae type b vaccines differed markedly in ability to stimulate antibody production. Mean antibody levels after three injections of polyribosylribitol phosphate conjugated with mutant diphtheria protein (PRP-CRM) or polyribosylribitol phosphate conjugated with tetanus toxoid (PRP-T) were 3.08 micrograms/ml and 3.64 micrograms/ml, respectively, significantly higher than those after the use of polyribosylribitol phosphate conjugated with outer-membrane protein of Neisseria meningitidis (PRP-OMP) (1.14 micrograms/ml) or polyribosylribitol phosphate conjugated with diphtheria toxoid (PRP-D) (0.28 microgram/ml). Only PRP-OMP produced a clinically pertinent elevation in antibody level after two injections (0.84 microgram/ml); the third injection of PRP-OMP produced a modest but statistically significant further elevation in mean antibody level (1.14 micrograms/ml). Only 29% of infants receiving PRP-D had antibody levels of 1 micrograms/ml, compared with 55%, 75%, and 83% of those receiving PRP-OMP, PRP-CRM, and PRP-T, respectively. We conclude that all four vaccines are safe and that all but PRP-D appear appropriate for use in a primary immunization series during infancy. The unique serologic response to PRP-OMP offers both advantages and disadvantages in comparison with PRP-CRM and PRP-T.
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PMID:Comparative trial in infants of four conjugate Haemophilus influenzae type b vaccines. 162 87

Polymorphonuclear neutrophils (PMN) in bovine uterine flushings following intrauterine deposition of killed bacteria were measured and the effect of immune status on the influx of PMN into the uterine lumen during oestrus was determined. Holstein heifers were immunized with a 270-kDa outer-membrane protein (omp-270) from Haemophilus somnus. During oestrus, immunized heifers (n = 21) received an intrauterine inoculum of either a heat-killed suspension of a homologous strain of H. somnus containing omp-270 (n = 7), a heterologous strain of H. somnus lacking omp-270 (n = 7), or phosphate-buffered saline (n = 7). Five additional heifers were inseminated with extended bovine semen. Uterine contents were collected in saline lavage immediately before inoculation (t0) and at 6, 24, 48, 72, 96, and 120 h after inoculation. The semen-inoculated heifers were lavaged only at t120. All groups experienced PMN infiltration which peaked 6 h after inoculation and tended to decline thereafter. Differences were not observed between treatment groups, indicating that neither bacterial inoculation nor immune status was as important in eliciting PMN effusion as the flushing procedure itself.
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PMID:Neutrophil migration into the bovine uterine lumen following intrauterine inoculation with killed Haemophilus somnus. 178 53

An enzyme-linked immunosorbent assay (ELISA) has been developed and validated to quantitate IgG1 and IgG2 antibody to polyribosyl-ribitol phosphate (PRP), the capsular polysaccharide of Haemophilus influenzae type b (Hib). The sera of children and infant Rhesus monkeys immunized with an Hib conjugate vaccine composed of Hib PRP covalently linked to an outer membrane protein complex (OMPC) from Neisseria meningitidis serogroup B (PedvaxHIB, PRP-OMPC, Merck, Sharp and Dohme Research Laboratories). The solid-phase antigen employed in the ELISA is a conjugate of PRP to human serum albumin. The enzyme-labeled antibody is alkaline phosphatase-conjugated mouse monoclonal (mAb) anti-human IgG1 or IgG2. A human serum standard was calibrated using parallel titrations with a known antibody standard. The geometric mean titer (GMT) of the anti-PRP IgG1 response to one dose of PedvaxHIB was 3.87 micrograms/ml (n = 82), 11.80 micrograms/ml (n = 62) and 14.57 micrograms/ml (n = 74) in infants and children 12 to 17 months, 18 to 23 months and greater than or equal to 24 months old, respectively. Infants 2 to 11 months old responded with an IgG1 anti-PRP response of 7.10 micrograms/ml while infant monkeys responded with a GMT of 150.65 (n = 9) after two doses of vaccine. The anti-PRP IgG2 GMT responses in all groups were less than 0.25 micrograms/ml, except for humans greater than or equal to 18-months old who exhibited a GMT of greater than or equal to 0.40 micrograms/ml (n = 75). PedvaxHIB, immunization of human infants and children and infant Rhesus monkeys elicits primarily an IgG1 response to PRP. The monkey model appears to be a reliable indicator of the human immune response.
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PMID:An enzyme-linked immunosorbent assay for quantitation of Haemophilus Influenzae type b polysaccharide-specific IgG1 and IgG2 in human and infant rhesus monkey sera. 180 88

Haemophilus influenzae b - Neisseria meningitidis group B outer membrane protein conjugate vaccine (Hib-OMP) was given to 571 children 2-60 months of age. Two doses of Hib-OMP were given, 2 months apart, to 2-11 month old infants, and a single dose to children 12-60 month old. Sera were obtained from a subset of vaccinees at each immunization, and at follow-up 1 month and 1 year after immunization. Geometric mean antibody concentration (micrograms/ml) before and after full immunization were respectively 0.111 and 3.549 for 2-3 month old, 0.108 and 5.048 for 4-5 month old, 0.082 and 6.933 for 6-11 month old; they were 0.103 and 3.500 for 12-17 month old, 0.167 and 7.791 for 18-23 month old and 0.243 and 12.781 for children greater than or equal to 24 months. Detectable antibody (greater than or equal to 0.125 micrograms/ml) failed to develop in 2/399 (0.5%) after primary immunization, and 12/252 (4.8%) lost detectable antibody 1 year later. Six of these 12 infants were less than 12 month old. The vaccine was immunogenic as early as 3-5 months of age. The need for booster immunization needs to be assessed.
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PMID:Immunogenicity and reactogenicity of Haemophilus influenzae type b-meningococcus group B outer membrane protein conjugate vaccine in children 2-60 months of age. 181 40

The protein PpIA (19 kD) cloned from a genomic library of Legionella pneumophila, Philadelphia 1, represents a peptido-glycan associated outer membrane protein in recombinant E. coli K-12 and L. pneumophila. It exhibits distinct sequence homology to lipoproteins of Haemophilus influenzae and E. coli. A ppIA specific DNA probe generated by PCR was used in Southern hybridizations of chromosomal DNA of Legionella strains and other Gram-negative pathogens. Under conditions of high stringency, hybridization could only be observed in L. pneumophila isolates, but all other Legionella strains tested displayed hybridization under lower stringency. No signals appeared after hybridization of chromosomal DNA from a variety of other bacteria. Using anti-PpIA monospecific polyclonal antibodies in Western blots, it was demonstrated that PpIA related proteins of nearly the same size are found in all L. pneumophila isolates and in a variety of, but not all, the Legionella species analysed here.
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PMID:Phenotype versus genotype of the 19 kD peptido-glycan associated protein of Legionella (PpIA), among Legionellae and other gram-negative bacteria. 181 89

The ability of three different oligonucleotide probes to identify different oral strains of Fusobacterium nucleatum was tested. Probes 119 and 214 were designed on the basis of known amino acid sequences from the N-terminal end of an outer membrane protein of F. nucleatum strain Fev1. Probe H 2.1, was a randomly cloned chromosomal DNA fragment of 2.1 kbp. The specificities of the probes were examined by testing each of them against a panel of five other species of Fusobacterium (six strains), oral and non-oral, and also against seven different oral species of six other genera. The chromosomal DNA of the bacteria to be examined was digested to completion using the restriction enzymes HincII, HindIII, EcoRI, EcoRV and Sau3AI. Digests were run on agarose gels and subjected to southern blotting before being hybridized with the probe in question. The results were confirmed by running a slot blot of genomic DNA from all of the 19 strains and hybridizing with a probe H 2.1. Probe H 2.1 turned out to be the most specific and useful of the three probes investigated. By use of this probe, interstrain identification of the six different strains of F. nucleatum could be performed and the strains could be distinguished from other oral species found in the oral cavity, such as Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, Capnocytophaga sputigena, Porphyromonas (Bacteroides) gingivalis, Eikenella corrodens and Leptotrichia buccalis. The probe reacted weakly with other non-oral species of the genus Fusobacterium, and there was no problem in distinguishing between the different strains.
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PMID:Use of synthetic oligonucleotide DNA probes for the identification of different strains of Fusobacterium nucleatum. 183 56


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