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)

A mutant of Haemophilus influenzae which does not discriminate between low efficiency (LE) and high efficiency (HE) markers has been isolated. The mutant does not differ wild type in its sensitivity to ultraviolet radiation, methyl methanesulfonate (MMS) mitomycin C, and nitrous acid. Spontaneous mutation frequencies for three loci studied are 10- to 30-fold higher in the mutant than in the wild type strain. Low- and high-efficiency transforming markers are equally UV-resistant when assayed on this mutant. This mutant is thus similar to the hex mutant of Streptococcus pneumoniae.
Mol Gen Genet 1979 Sep
PMID:A hex mutant of Haemophilus influenzae. 31 97

Restriction endonuclease R from Bacillus subtilis strain R cleaves nonmodified SPP 1 DNA in approximately 80, and lambda DNA in about 200 different sites. DNA digests with this endonuclease and with endonuclease Hae III from Haemophilus aegyptius show identical fragmentation patterns on gel electrophoresis, indicating that the two enzymes recognise the same nucleotide sequence. The polynucleotide kinase reaction was used in conjunction with two-dimensional ionophoretic nucleotide mapping methods to identify the 5'-nucleotide sequences at the sites of cleavage by the B. subtilis restriction endonuclease. The results show that the recognition sequence is (see article) where arrows indicate the points of strand scission. Each of the four possible nucleotides can occur in the positions flanking the recognition site.
Mol Gen Genet 1975 Dec 30
PMID:Restriction and modification in B. subtilis. Nucleotide sequence recognised by restriction endonuclease R. Bsu R from strain R. 81 3

A strain of Haemophilus influenzae, called hpm- inhibits the growth of phage HP1c1 but not S2. This inhibition is overcome by HP1c1ph mutants. Phage HP1c1 adsorbs normally to hpm- cells but only a small fraction of infected cells produce phage with a normal burst size or become lysogenic. When hpm- strains lysogenic for HP1c1 are induced, 100 percent of the cells yield phage. There is no degradation of phage DNA after infection of hpm- cells and HP1c1 can normally grow when its DNA is introduced into hpm- by transfection. The most probable explanation is that in hpm- cells the penetration of phage DNA is blocked. The hpm- property behaves as as unstable mutation.
Mol Gen Genet 1975 Aug 05
PMID:An Haemophilus influenzae mutant which inhibits the growth of HP1c1 phage. 108 Aug 31

Vegtative recombination of temperature-sensitive mutants of Haemophilus influezae bacteriophage N3 was measured in wild-type H. influenzae strain Rd9 and in recombination-defective mutants of the Rd strain. Recombinants are formed with low but equal frequency in wild-type cells and recombination-defective mutants of the Rd strain. It is concluded that this phage can carry information in its own genome for vegetative recombination. Lysogenization readily takes place in both strains.
Mol Gen Genet 1976 Aug 10
PMID:Bacteriophage N3 of Haemophilus influenzae. I. Independence of vegetative recombination among Haemophilus influenzae bacteriophage on the host cell. 108 11

A murine monoclonal antibody (mAb), designated 3H12, reacts with a surface-exposed conformational epitope on the pilus of non-typable Haemophilus influenzae strain M37. This antibody does not recognize the related pilus from H. influenzae type b, strain MinnA. Although mAb 3H12 does not recognize strain M37 pilin on Western blots, mAb 3H12 recognizes the recombinant M37 pilin protein expressed by Escherichia coli. In order to map the epitope recognized by mAb 3H12, we constructed a series of chimaeric genes. The chimaeric genes were expressed in E. coli and the chimaeric proteins characterized with respect to their reactivity with mAb 3H12. Residues between 37 and 100 of the M37 pilin protein are essential for the expression of the mAb 3H12 epitope. Residues in the carboxyl half of the M37 protein enhance the reactivity of mAb 3H12 when expressed in the presence of residues 37-100. Construction of chimaeric genes may provide a general methodology for mapping of conformational epitopes expressed by one of a related pair of proteins.
Mol Microbiol 1992 Sep
PMID:Construction of chimaeric genes for mapping a surface-exposed epitope on the pilus of non-typable Haemophilus influenzae strain M37. 128 Mar 16

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.
Mol Microbiol 1992 Oct
PMID:The gal locus from Haemophilus influenzae: cloning, sequencing and the use of gal mutants to study lipopolysaccharide. 128 42

Length variations of Haemophilus influenzae outer membrane porin protein P2 were found at the DNA and protein levels, notably in non-capsulate strains. Protein length, measured by SDS-polyacrylamide gel electrophoresis, was found to correlate with the length of the gene, measured by polymerase chain reaction amplification, and ranged from 35-42 kDa and 970-1090 nucleotides, respectively. This represents a length variation of some 15%. The genetic location of these variations was studied by restriction enzyme mapping 10 of the non-capsulate strains revealing further polymorphisms at the DNA level. All 10 strains were distinct and differed from a type b strain. The conservation and assortment of the different restriction sites in the alleles is discussed in relation to the very great diversity previously described for this protein and of the whole genome itself in non-capsulate strains. The roles of selection, horizontal gene transfer, and transformation in generating this diversity are discussed.
Mol Microbiol 1992 Aug
PMID:Variation in length and sequence of porin (ompP2) alleles of non-capsulate Haemophilus influenzae. 132 12

The major outer membrane protein of Haemophilus influenzae type b (Hib) is porin (Mr 38,000, 341 amino acids). To identify antigenic determinants on Hib porin that might be exposed at the bacterial cell surface, seven mouse monoclonal anti-Hib porin antibodies were generated. The monoclonal antibodies were tested for their binding to intact cells by flow cytometry; all but one bound to the cell surface. Digestions of Hib porin with cyanogen bromide, hydroxylamine or trypsin generated fragments, the identities of which were confirmed by microsequencing of the amino termini. Following electrophoresis and immunoblotting of the fragments, the specificities of the monoclonal antibodies for their cognate sequences were determined. The porin gene ompP2 was expressed in the baculovirus expression vector system; the recombinant porin was recognized by all of the monoclonal antibodies. Deletions were created by omega mutagenesis of ompP2, generating proteins truncated after amino acids 139, 174, 182, and 264. These deletion proteins were tested for reactivities with the monoclonal antibodies, thereby establishing the boundaries of three antigenic determinants that were recognized by the monoclonals: domain (i), amino acids 104-139; domain (ii) amino acids 162-174; and domain (iii), amino acids 267-341. The biological activities of monoclonal antibodies that were representative of these three classes were tested for their bactericidal activity in complement-mediated lysis of whole cells. The monoclonal antibodies were also tested for their immunoprotective properties in the infant rat model of bacteraemia. Although the monoclonal antibodies were surface-binding, they were neither bactericidal nor protective.
Mol Microbiol 1992 Mar
PMID:Monoclonal antibodies specific to porin of Haemophilus influenzae type b: localization of their cognate epitopes and tests of their biological activities. 137 79

We previously reported the analysis of recombinant plasmids from Haemophilus influenzae type b (Hib) that lead to modifications of Escherichia coli lipopolysaccharide (LPS) (Y. Abu Kwaik, R. E. McLaughlin, M. A. Apicella, and S. M. Spinola, Mol. Microbiol. 5:2475-2480, 1991). The modified LPS species are recognized by monoclonal antibodies (MAbs) 6E4 and 3F11. MAb 6E4 binds to a stable 2-keto-3-deoxyoctulosonic acid epitope, while MAb 3F11 binds to a Gal beta 1-4GlcNac epitope that phase varies in Hib at a frequency of 2 to 5%. The internal EcoRI fragment containing most of the DNA required for LPS modification in E. coli was used as the target for transposon mutagenesis. Plasmids containing minitransposon m-Tn3(Cm) randomly inserted into the target fragment were transformed into the isogenic Hib strain, and transposon integration into the Hib chromosome was verified by colony hybridization. The lipooligosaccharides of 36 transformants were phenotypically and antigenically characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and reactivity with a variety of MAbs that recognize both stable and phase-varying lipooligosaccharide epitopes. The majority of the mutants had altered reactivity with MAb 6E4. With one exception, these mutants retained the ability to express phase-varying epitopes. Analysis of the transformants suggested that the 6E4 epitope was contained on an oligosaccharide chain separate from that of phase-varying epitopes and appeared to be assembled in at least three separate steps.
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PMID:Generation of lipooligosaccharide mutants of Haemophilus influenzae type b. 140 Jan 98

Linked genes encoding two outer membrane proteins (p76 and a family of proteins, p120) of the bovine pathogen, Haemophilus somnus, were investigated. The p120 group was previously shown to have immunoglobulin-binding activity and to react with polyclonal antiserum specific for a 270 kDa antigen (p270) which also had immunoglobulin Fc-binding activity. By Western blotting we showed that the p76 antigen also reacted with this antiserum. The p270, p120, and p76 antigens were undetectable in four serum-sensitive isolates from asymptomatic carriers but were present in the two serum-resistant virulent strains tested. Genes for p120 and p76 were subcloned on non-overlapping pUC plasmids from a cosmid (pHS1) originally cloned from a serum-resistant strain. In Escherichia coli, plasmid pHS138 expressed p76, while the p120 antigens were produced by pHS140. Southern blots of DNA from the above six strains of H. somnus using probes derived from pHS1 subclones showed that a 13.4 kb sequence was missing from the four serum-sensitive strains, but not the two serum-resistant strains. This segment included most of the insert in pHS138 and all of the pHS140 insert. The data indicate that p76 and the p120 proteins are absent from serum-sensitive strains because the coding sequences are missing, raising the possibility of insertion of these genes into the chromosome of both serum-resistant strains, or deletion from the four serum-sensitive strains.
Mol Microbiol 1992 Jul
PMID:Two linked genes for outer membrane proteins are absent in four non-disease strains of Haemophilus somnus. 150 38


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