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)

Bacterins prepared from 7 strains of Haemophilus gallinarum were used to immunized chickens for cross-protection studies. Three distinct immunotypes were distinguished. Slight protection between immunotypes was evident for some strains. Airsacculitis could be prevented by use of these bacterins; however, prevention was related to immunotype specificity. Hyaluronic acid found in 2 strains rendered them inagglutinable in homologous antiserums. Treatment with hyaluronidase rendered them agglutinable.
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PMID:Infectious coryza: cross-protection studies, using seven strains of Haemophilus gallinarum. 93 Nov 40

Haemophilus (Actinobacillus) pleuropneumoniae Serotypes 5 and 7 capsular antigens (CA-1) were precipitated from culture supernatants with N-cetyl-N,N,N,-trimethylammonium bromide (Cetavlon). CA-1 contained a carbohydrate to protein ratio of 2:1 for Serotype 5 and 3:1 for Serotype 7. Glucosamine and uronic acid were detected in CA-1 from both serotypes suggesting that the capsule contained hyaluronic acid. All mice immunized intraperitoneally with CA-1 vaccine were protected from death when challenged with 10X the LD50 of the homologous but not the heterologous serotype. Oil adjuvants and the use of young (6 h) cultures were necessary for CA-1 vaccines to be protective. Deproteinization of CA-1 with chloroform and butanol followed by pronase treatment resulted in failure to protect mice from death. The protective capsular protein antigen in CA-1 vaccine may not originate from the outer membrane (OM) since repeated washing of the OM to elute the capsular protein antigen rendered the OM vaccine completely nonprotective for mice. Vaccines prepared from cell-wall lipopolysaccharide also were nonprotective for mice. Passive immunization of mice with anti-CA-1 antibody produced in rabbits to Serotype 5 was highly protective (P less than 0.01) for mice when challenged with 10X the LD50 of the homologous serotype.
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PMID:Protection of mice against the lethal effect of an intraperitoneal infection with Haemophilus (Actinobacillus) pleuropneumoniae after vaccination with capsular proteins. 323 18

Relationships between morphological or serological properties and virulence were investigated in seven Haemophilus paragallinarum variants. The variants, originated from five serotype 1 strains, were classified into seven types on the basis of colony morphology and iridescence and the presence of variant-specific antigens. Smooth (S) and encapsulated organisms having variant-specific antigens and forming highly iridescent (ir+) colonies were highly virulent in vivo; slightly encapsulated organisms having variant-specific antigens and forming slightly iridescent (ir +/-) colonies were moderately virulent; and nonencapsulated or slightly encapsulated organisms with or without variant-specific antigens and forming noniridescent (ir-) or ir +/- colonies were avirulent. Virulence was well correlated with the amount of capsule substance containing hyaluronic acid. The evidence suggests that the presence of variant-specific agglutinogen L and hemagglutinin HA-L seem to be responsible for adherence or colonization, but not for virulence, of the organisms in chickens.
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PMID:Relationships between virulence and morphological or serological properties of variants dissociated from serotype 1 Haemophilus paragallinarum strains. 688 91

A family of high-molecular-weight (HMW) surface-exposed proteins of nontypeable Haemophilus influenzae (NT H. influenzae) mediated adherence of these organisms to human epithelium. To better understand the molecular basis for this adherence, the role of glycosaminoglycans (GAGs), substances commonly expressed on cell surfaces, was examined. Bacterial adherence to cells with specific deficiencies in GAG biosynthesis was measured. HMW protein-dependent bacterial adherence to normal cells was significantly greater than adherence to cells deficient in sulfated GAGs or to cells deficient in heparan sulfate but overexpressing chondroitin sulfate. Cells expressing undersulfated heparan sulfate exhibited intermediate levels of bacterial adherence. The addition of exogenous dextran sulfate or heparin inhibited over 70% of the adherence of NT H. influenzae to normal cells, whereas hyaluronic acid and chondroitin sulfate tested at the same concentration (100 micrograms/ml) inhibited bacterial adherence by less than 11%. Treatment of cells with heparinase significantly reduced bacterial adherence. Following electrophoretic separation, HMW proteins were shown to bind directly to radiolabeled heparin. These results indicate that HMW protein-dependent adherence of NT H. influenzae is mediated by cellular sulfated GAGs and that heparan sulfate may be the predominant GAG involved in this process. However, the decreased adherence of bacteria to cells expressing undersulfated heparan sulfate and the inhibition of bacterial adherence by the addition of exogenous dextran sulfate suggest that bacterial adhesion to mammalian cells is likely to be influenced by a variety of factors, including the degree of sulfation and the specificity of the carbohydrate moieties contained in the cellular proteoglycans.
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PMID:High-molecular-weight proteins of nontypeable Haemophilus influenzae mediate bacterial adhesion to cellular proteoglycans. 806 23

Haemophilus somnus can cause a devastating fibrinopurulent meningitis with thrombotic vasculitis and encephalitis in cattle. The mechanisms used by H. somnus to migrate from the bloodstream into the central nervous system (CNS) are unknown. In this study, we demonstrate that H. somnus adheres to, but does not invade, bovine brain endothelial cells (BBEC) in vitro. The number of adherent H. somnus was significantly increased by prior activation of the BBEC with tumor necrosis factor alpha (TNF-alpha). Addition of exogenous glycosaminoglycans significantly reduced H. somnus adherence to resting and TNF-alpha-activated BBEC. Heparinase digestion of the endothelial cell's glycocalyx or sodium chlorate inhibition of endothelial cell sulfated glycan synthesis significantly reduced the number of adherent H. somnus. In contrast, addition of hyaluronic acid, a nonsulfated glycosaminoglycan, had no inhibitory effect. These findings suggest a critical role for both cellular activation and sulfated glycosaminoglycans in adherence of H. somnus to BBEC. Using heparin-labeled agarose beads, we demonstrated a high-molecular-weight heparin-binding protein expressed by H. somnus. Heparin was also shown to bind H. somnus in a 4 degrees C binding assay. These data suggest that heparin-binding proteins on H. somnus could serve as initial adhesins to sulfated proteoglycans on the endothelial cell surface, thus contributing to the ability of H. somnus to infect the bovine CNS.
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PMID:Roles of cellular activation and sulfated glycans in Haemophilus somnus adherence to bovine brain microvascular endothelial cells. 1692 25

To address the problem of limited efficacy of existing antibiotics in the treatment of bacterial biofilm, it is necessary to find alternative remedies. One candidate could be hyaluronic acid; this study therefore aimed to evaluate the in vitro antiadhesive and antibiofilm activity of hyaluronic acid toward bacterial species commonly isolated from respiratory infections. Interference exerted on bacterial adhesion was evaluated by using Hep-2 cells, while the antibiofilm activity was assessed by means of spectrophotometry after incubation of biofilm with hyaluronic acid and staining with crystal violet. Our data suggest that hyaluronic acid is able to interfere with bacterial adhesion to a cellular substrate in a concentration-dependent manner, being notably active when assessed as pure substance. Moreover, we found that Staphylococcus aureus biofilm was more sensitive to the action of hyaluronic acid than biofilm produced by Haemophilus influenzae and Moraxella catarrhalis. In conclusion, hyaluronic acid is characterized by notable antiadhesive properties, while it shows a moderate activity against bacterial biofilm. As bacterial adhesion to oral cells is the first step for colonization, these results further sustain the role of hyaluronic acid in prevention of respiratory infections.
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PMID:Antiadhesive and antibiofilm activity of hyaluronic acid against bacteria responsible for respiratory tract infections. 2469 41