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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

During the process of transformation in Hemophilus influenzae integration of donor DNA, i.e. the formation of recombinant DNA, involves the incorporation of single-stranded DNA. Evidence was obtained from cesium chloride density gradient centrifugation of DNA from donor-recipient complexes that integration was accompanied by the formation of hybrid DNA with a density intermediate with respect to heavy, (2)H, (15)N, donor and light, (1)H, (4)N recipient DNA. On denaturation the position of the heavy donor DNA moved closer to, but not all the way toward, the density position of the original donor DNA. In addition to supporting the idea of single-stranded incorporation, this evidence suggested that the integrated donor DNA was covalently linked to light recipient DNA. The DNA was taken up in the double-stranded form and no detectable amounts of denatured DNA could be found during the transformation process. However, during the process of integration an amount of donor atoms, equivalent to the amount of hybrid DNA formed, appeared in recipient DNA, and indicated that while one strand of DNA was integrated the other was broken down and resynthesized. The density of the hybrid DNA, as well as rebanding of denatured hybrid, indicated that the size of the integrated piece of DNA was large, approximately 6 x 10(6) daltons.
J Gen Physiol 1966 Jul
PMID:On the nature of recombinants formed during transformation in Hemophilus influenzae. 529 73

The acids produced in broth culture by various species of oral haemophili and by stock strains of capsulated and other haemophili were identified and measured by gas-liquid chromatography. Succinic acid was the major acid end-product of all strains, with acetic acid also being regularly produced but in smaller amounts. A stock strain, Haemophilus parainfluenzae NCTC 4101, produced less succinic acid than other strains of haemophili. Strain NCTC 4101 possessed all the enzymes of the tricarboxylic acid cycle, as previously reported, but in the other haemophili examined only succinic dehydrogenase, fumarase and malate dehydrogenase could be detected. No other enzymes of the tricarboxylic acid cycle were detected and isocitrate lyase, malate synthase and pyruvate carboxylase were also absent. Phosphoenolpyruvate-carboxylase was present in all strains. A partial tricarboxylic acid cycle and marked malate dehydrogenase activity appear to be characteristic of haemophili. The pathway to succinate in haemophili appears to be via carboxylation of phosphoenolpyruvate to oxalacetate and thence via malate and fumarate. The results of tracer studies on a single oral strain of H. parainfluenzae using various labelled substrates were in keeping with this proposed metabolic pathway.
J Gen Microbiol 1984 Jul
PMID:The acid end-products of glucose metabolism of oral and other haemophili. 633 75

We examined bactericidal and opsonizing activity of pooled adult 'immune' serum against Haemophilus influenzae type b with and without the addition of phagocytes. Four type b strains from cerebrospinal fluid (CSF) and three such strains from the nasopharynx (NP) of healthy children were examined. Duplicate reaction mixtures contained organisms in exponential (E) or stationary phase (S) of growth, serum, a complement source (human agammaglobulinaemic serum), and culture medium (bactericidal assay); separate assays contained the above components and polymorphonuclear leucocytes (opsonization system). A decrease in bacterial density of greater than or equal to 1 log10 unit was considered significant. All four S-CSF strains, three of four E-CSF strains and one of three S-NP strains were sensitive to the bactericidal activity of pooled serum. The other E-CSF strain, two S-NP strains and all three E-NP strains were resistant to the bactericidal activity of pooled serum. Two of three E-NP strains were opsonized by pooled serum; the other strains resistant to the bactericidal activity of pooled serum were also resistant to opsonization. Bactericidal and opsonizing activity of serum from an immunized adult was greater than or equal to that of pooled serum against each strain. Assuming normal adults are immune to invasive H. influenzae type b infection, an experimental test reflecting this immunity is the bactericidal activity against CSF isolates tested in stationary phase. We conclude that protection against invasive disease due to H. influenzae type b appears more complex than the presence of bactericidal and opsonizing activity in serum.
J Gen Microbiol 1984 Mar
PMID:Human serum bactericidal activity against Haemophilus influenzae type b. 637 30

We studied the adherence of Haemophilus influenzae to monkey respiratory mucosa using nasal turbinates maintained in organ culture. Adherence of capsulated and rough strains was not inhibited by monosaccharides, sucrose, human albumin, foetal calf serum or polyribophosphate. However, antisera directed against surface components decreased bacterial adherence. Although variation in adherence capacity in individual strains was observed there was no correlation with capsulation, anatomical site of strain isolation or biotype. Bacterial surface structures other than capsular material appear important in effecting upper respiratory tract colonization.
J Gen Microbiol 1984 Jun
PMID:Adherence of Haemophilus influenzae to monkey respiratory tissue in organ culture. 643 95

Seven mutants of Haemophilus influenzae strain Rd (mmsA-) have been isolated that are more sensitive to methyl methane sulfonate (mms) than recombination-deficient (recA-) mutants. The mutations cotransformed about 25% with the strA locus while the five studied clustered tightly; they are all probably allelic. The mutants are not sensitive to ultraviolet radiation, X-rays, or nitrous acid. Mms-damaged phage HP1 plated very inefficiently on these mutants, indicating that they lack the first step in the excision repair of the lesion N3-methyladenine (m3A). Incubation of damaged phage at 30 degrees C in the absence of mms resulted in a steady decline of viability when the phage were plated on the wild mmsA+ host but an initial steep rise was seen when it was plated on an mmsA- mutant. The rise is explained by the assumption that m3A lesions hydrolyzed off the DNA giving rise to repairable apurinic sites by both the mmsA+ and mmsA- hosts. No decline in viability was observed when hydroxylamine was present in the medium. This compound is known to prevent or slow down beta-elimination. The delayed decline in viability is therefore explained by assuming that apurinic sites give rise to beta-elimination-induced single strand breaks in the phage DNA that cannot be repaired by either host. Marker rescue experiments indicated that these breaks did not interrupt injection of phage DNA.
Mol Gen Genet 1983
PMID:Repair of methyl methane sulfonate-damaged phage by Haemophilus influenzae. 660 66

The relationship between nine Haemophilus species and Haemophilus influenzae was studied by DNA-DNA hybridization, by transformation of H. influenzae to streptomycin resistance with heterospecific DNA, by competition of heterospecific DNA for transformation by homospecific DNA and by the lethal effect of heterospecific DNA on competent H. influenzae. H. parainfluenzae, H. parasuis, and H. aegyptius DNA transformed at more than 10% efficiency when compared to homologous transformation, but only H. aegyptius demonstrated, by hybridization, a relative binding ratio of more than 80%. H. aphrophilus and H. paraphrophilus DNA demonstrated a relative binding ratio of less than 30% and transformed H. influenzae at only 10(-5) the efficiency of homologous DNA, but they competed for H. influenzae transformation as well as or better than homospecific DNA. The data indicated that in some of the species sharing the common ecological habitat of the mammalian respiratory tract, sequences necessary for competition and efficient uptake into H. influenzae are present in large numbers in their DNAs, which nevertheless have little overall homology with H. influenzae DNA.
Mol Gen Genet 1984
PMID:Heterospecific transformation in the genus Haemophilus. 660 96

pLE2451, a 24.5 megadalton conjugative plasmid from Neisseria gonorrhoeae, was capable of efficiently mobilizing gonococcal beta-lactamase plasmids between gonococci and from gonococci to Haemophilus influenzae and restriction-deficient Escherichia coli. Donor strains of N. gonorrhoeae carrying pLE2451 were also found to be capable of mobilizing a variety of non-conjugative plasmids originally derived from enteric bacteria or Haemophilus species when such plasmids were resident in E. coli. Nevertheless, pLE2451 was not detected physically in E. coli or H. influenzae transconjugants. This suggests that the plasmid is unstable in these hosts but survives transiently to provide transfer functions for mobilization. The proficiency of pLE2451 in promoting intraspecific and intergeneric mobilization was not paralleled by pUB701, pRI234 and pFR16017, a series of conjugative plasmids derived originally from Haemophilus species. These plasmids were incapable of mobilizing even Haemophilus beta-lactamase plasmids, such as RSF0885, between Haemophilus species.
J Gen Microbiol 1981 Jul
PMID:Intraspecific and intergeneric mobilization of non-conjugative resistance plasmids by a 24.5 megadalton conjugative plasmid of Neisseria gonorrhoeae. 680 Nov 91

Cross-transformation and quantitative competition experiments showed that Neisseria gonorrhoeae and Haemophilus influenzae do not interact with each other's DNA in transformation. These organisms must interact with different recognition sequences during DNA uptake.
J Gen Microbiol 1982 May
PMID:Haemophilus influenzae and Neisseria gonorrhoeae recognize different specificity determinants in the DNA uptake step of genetic transformation. 680 88

Twenty recombinant influenza virus strains bearing HSw1N1, H1N1 or H3N2 surface antigens, together with their respective wild-type or laboratory-propagated parent viruses, were inoculated into 2 day-old infant rats and their replication in the turbinates and lungs of these animals observed over a period of 5 days. In addition, the ability of each of the recombinant and parent viruses to enhance a subsequent infection of these infant rats by Haemophilus influenzae type b was determined. The results showed that both parent and recombinant viruses replicated less well in the lungs than in the turbinates of infant rats, but the titres in both tissues were generally lower for the recombinant strains. The capacity of the majority of the recombinant influenza viruses to promote bacterial infection of the infant rats, as determined by the incidence of H. influenzae bacteraemia and meningitis, was also markedly less than that of their parent viruses. A correlation between virulence for man and both the replication in infant rat turbinates and the ability to enhance H. influenzae infection, was established for the virus strains studied. The data are discussed in relationship to the value of the infant r-H influenzae system as a laboratory marker for the determination of the virulence of influenza virus strains.
J Gen Virol 1980 Aug
PMID:The replication of type A influenza viruses in the infant rat: a marker for virus attenuation. 696 91

Fifty-five strains received as Haemophilus vaginalis or as catalase-negative coryneform bacteria from the vagina together with 61 marker cultures were subjected to numerical phenetic analyses using 149 unit characters. The data were examined using the simple matching (SSM), Jaccard (SJ) and pattern (DP) coefficients and clustering was achieved using the average linkage algorithm. Cluster composition was not markedly affected by the coefficient used or by test error, estimated at 6 . 5%. The H. vaginalis strains formed a tight cluster which was only distantly related to representatives of the genera arthrobacter, Cellulomonas, Corynebacterium sensu stricto, Erysipelothrix, Haemophilus, Kurthia, Lactobacillus, Listeria and Propionibacterium but shared a high overall affinity to unclassified catalase-negative coryneforms which formed a discrete taxon, cluster 9. The H. vaginalis strains could be distinguished from the related strains in cluster 9 by several unrelated phenotypic characters. Using the S1 endonuclease assay, DNA-DNA hybridizations were performed with representative strains from the numerical as well as with reference strains of Bifidobacterium and Actinomyces. Haemophilus vaginalis was found to be a genotypically legitimate group and its DNA showed little homology with DNA from the marker strains tested. The DNA base composition of H. vaginalis was 42 to 44 mol % guanine plus cytosine. A new genus should be created to incorporate strains known as H. vaginalis or Corynebacterium vaginale. The name Gardnerella vaginalis proposed by Greenwood & Pickett (1979) is supported.
J Gen Microbiol 1980 Aug
PMID:A taxonomic study of Gardnerella vaginalis (Haemophilus vaginalis) Gardner and Dukes 1955. 697 16


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