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Query: UNIPROT:O75191 (H. influenzae)
 4,961 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lipopolysaccharide from strains of Haemophilus influenzae was extracted and isolated by the hot phenol-water procedure. The preparations were relatively insoluble in water but could be solubilized with surface-active agents. The preparations contained carbohydrate (30%), fatty acid (29%), and phosphate (4.7%); protein content was less than 1%. Thin-layer chromatography, gas-liquid chromatography, and colorimetric assays detected glucose, galactose, glucosamine, heptose, and a 2-keto-3-deoxy-octonate-like molecule (less than 1%). Neither methylpentose nor dideoxyhexose was detected. The lipid portion was composed of fatty acids common to lipopolysaccharide of Salmonella. The preparations provoked positive dermal Shwartzman reactions and biphasic febrile responses in rabbits, responses typical of endotoxic activity. The 50% lethal dose for mice was decreased from 16.5 microgram/g to 0.015 microgram/g by concomitant administration of actinomycin D. The preparations were shown to be polyclonal activators of bone marrow-derived (B) cells. Limulus lysate gelation was seen with 8.0 ng of lipopolysaccharide. Preliminary hemagglutination data suggested at least three different antigenic factors associated with the lipopolysaccharide of H. influenzae type b. The H. influenzae lipopolysaccharide appeared biologically similar to that of enterobacteria but chemically different.
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PMID:Characterization of lipopolysaccharide of Haemophilus influenzae. 31 Aug 55

Ribonucleic acid was removed from a phenol-water extract of Haemophilus influenzae type a by streptomycin sulfate. This preparation was called purified preparation or PP. It contained neutral sugars (glucose, galactose, mannose, pentose), glucosamine, amino acids, and fatty acids. Heptose and 2-keto-3-deoxyoctonic acid were not present. The biological properties and immunogenicity were compared with the activities of lipopolysaccharide of Escherichia coli or Salmonella typhimurium. Higher doses were necessary to obtain lethality in mice and Sanarelli and Shwartzman reactions with our preparations than were necessary with lipopolysaccharide. The Limulus test and pyrogen assay in rabbits gave the same results with purified preparation and lipopolysaccharide, but pyrogenicity of purified preparation was not destroyed by NaOH treatment. Purified preparation was not as immunogenic at low doeses for rabbits as lipopolysaccharide. The results were different from those obtained with lipopolysaccharide but similar to those known from peptidoglycan studies. The contamination of purified preparation with peptidoglycan was negligible and cannot explain the biological activities of purified preparation. We suggest that the phenol-water extract from H. influenzae is not a classical endotoxin, but rather an endotoxin-like substance.
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PMID:Chemical composition and biological activities of a phenol-water extract from Haemophilus influenzae type a. 31 93

During bacteriophage studies on Haemophilus influenzer, it was observed that encapsulated type b and unencapsulated Rb strains released a bactericidal substance acitve against types a, c, d, e, and f H. influenzae, non-typable H. influenzae strains, other Haemophilus species, and certain members of the Enterobacteriaceae. The bactericidal activity was assayed by a plaque test utilizing an Rd strain as an indicator lawn and was also demonstrated in mixed broth cultures of a producer strain and an indicator strain. Immediately lysis of sensitive bacteria by the factor was not evident. The factor is sensitive to trypsin but resistant to deoxyribonuclease, treatment with 2-mercaptoethanol, lipase, alpha-amylase, and heating in a 100 degrees C water bath for 20 min. The activity is not dependent upon increased Ca2+ or Mg2+ concentration as is necessary for HP1C1 and S2 phage propagation. The bactericidal factor is not pelleted by high-speed centrifugation at 150,000 X g for 6 h. Treatment with ultraviolet light or mitomycin C does not result in observable phage, phage-like particles, or increased bactericidal activity. T-HE BACTERICIDAL FACTOR IS NOT A TYPICAL SMALL MOLECULAR WEIGHT "COLICIN-LIKE" BACTERiocin in that it is not inducible, has a wider range of activity, and does not kill by "single-hit" kinetics. On preliminary characterization, it is a thermostable protein toxic to certain bacterial strains.
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PMID:Bactericidal substance produced by Haemophilus influenzae b. 108 28

Antiinflammatory therapy has been shown to reduce the adverse pathophysiological consequences that occur in bacterial meningitis and to improve outcome from disease. In the present study, modulation of two principal steps of the meningeal inflammatory cascade was accomplished by concomitant administration of dexamethasone to diminish overproduction of cytokines in response to a bacterial stimulus and of a monoclonal antibody directed against adhesion-promoting receptors on leukocytes to inhibit recruitment of white blood cells into the subarachnoid space. Dexamethasone and antibody therapy produced a marked attenuation of all indices of meningeal inflammation and reduction of brain water accumulation after H. influenzae-induced meningitis in rabbits compared with results of each agent given alone and of untreated animals. In addition, the enhanced host's meningeal inflammatory reaction that follows antibiotic-induced bacterial lysis was profoundly ameliorated when dual therapy was administered without affecting clearance rates of bacteria from cerebrospinal fluid and vascular compartments. The combination of both therapeutic approaches may offer a promising mode of treatment to improve further the outcome from bacterial meningitis.
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PMID:Enhanced attenuation of meningeal inflammation and brain edema by concomitant administration of anti-CD18 monoclonal antibodies and dexamethasone in experimental Haemophilus meningitis. 168 64

We evaluated the consequences of prolonging the time between initial bacterial inoculum suspension preparation and susceptibility test inoculation. Extending the current National Committee for Clinical Laboratory Standards-recommended time of 15 min between suspension preparation and test inoculation should allow laboratories more flexibility to optimize efficiency from the standpoint of workflow. We assessed the length of time for which viable-bacterium counts remain stable in three liquid media at room temperature. Fifty isolates were examined in water, saline, and cation-supplemented Mueller-Hinton broth (CSMHB). Disk diffusion and microdilution MIC tests were performed on nine of these. Our results suggest that directly prepared inoculum suspensions of members of the family Enterobacteriaceae, Pseudomonas aeruginosa, staphylococci, and enterococci can be held for up to 6 h in water or saline prior to inoculation of disk diffusion and MIC tests without compromising test accuracy. The same organisms can be held for at least 1 h in CSMHB. Viridans group streptococci can be held for up to 6 h in saline and CSMHB and for up to 3 h in water. Similarly, Haemophilus influenzae and Streptococcus pneumoniae isolates may be held in CSMHB for up to 3 h. Because of an early decrease in viable-bacterium counts in water and saline with some H. influenzae and S. pneumoniae isolates, we recommend that National Committee for Clinical Laboratory Standards recommendations be followed for these species.
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PMID:Stability of viable-bacterium counts in liquid media used for preparation of inocula and subsequent impact on antimicrobial susceptibility test results. 238 Mar 55

The 40-kDa porin protein of Haemophilus influenzae type b was reconstituted into proteoliposomes. The relative rates of diffusion of small uncharged sugars across the channels formed by this protein were determined by measuring the rates of osmotic swelling of the liposomes. From these rates, a pore diameter of 1.8 nm was estimated using the Renkin equation. A chemical cross-linking technique was used to investigate the oligomeric structure of the 40-kDa porin. Sodium dodecyl sulfate - polyacrylamide gel electrophoresis revealed the presence of porin dimers and trimers after reaction of the protein with dithio-bis-(succinimidyl propionate). These results confirmed that the porin of H. influenzae forms large water-filled channels and indicated that it probably exists as trimers in the outer membrane.
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PMID:Outer membrane porin protein of Haemophilus influenzae type b: pore size and subunit structure. 245 50

The endotoxin (lipopolysaccharides, LPS) of H. influenzae extracted with phenol-water method was injected into the perilymphatic compartment of guinea pig via the round window membrane. The CAP thresholds of the cochleas injected with LPS rose to 70.00 +/- 21.76 dB. The N1 latency at threshold prolonged until 2.63 +/- 0.28 ms. Compared with the controls, the differences were significant statistically at the level of 1% and 5% respectively. Electron microscopy found that the neural fibers of the organ of Corti were swollen, organelles degenerated, axon atrophied and disappeared. The myelin sheaths collapsed. The organelles and vesicles in the synapses decreased and disappeared. The synaptic membrane destroyed. The results exhibited that the LPS of H. influenzae had toxic effects on the neural components of the organ of Corti and the degeneration of the neural components was the pathological basis of the elevation of CAP thresholds and the N1 latency delay. It is concluded that once endotoxin enters into the perilymphatic compartment, it not only causes physiological changes but results in irreversible alterations of the neural components pathologically.
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PMID:[Damage caused by endotoxin of the neural components of the organ of Corti]. 263 14

Lipopolysaccharide endotoxin (LPS) was extracted from Haemophilus influenzae type b by using Westphal's phenol water method. The ears of 40 adult male guinea pigs were subsequently inoculated with 10 micrograms/ml solutions of LPS by transmeatal injections. Groups of animals were then sacrificed from day 2 to day 24 after the injections to observe the pathological changes produced. Massive serous effusions filled the tympanic bullae on days 2 and 4, after which the amount of fluid present gradually decreased so that it could hardly be seen on day 11. Pathological changes found in the mucosa included marked interstitial edema, dilated capillaries, as well as elevated and thickened epithelium with intracellular edema. These findings gradually subsided by day 24. We believe that the major pathogenetic factors present were due to the transudation and injury of the middle ear epithelium disturbing mucociliary transport activity, with increased secretions participating somewhat in inducing the effusion. We further suggest that H. influenzae endotoxin may play an active role in the clinical development of otitis media with effusion.
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PMID:Otitis media with effusion following inoculation of Haemophilus influenzae type b endotoxin. 348 52

The lipooligosaccharides (LOS) of nontypable Haemophilus influenzae are an antigenically heterogeneous group of macromolecules. Immunodiffusion and enzyme-linked immunosorbent assay inhibition studies with phenol-water-extracted LOS and absorbed antisera specific for the oligosaccharide portion of the LOS identified six LOS strain-specific antigens. To facilitate screening large numbers of strains to search for LOS antigenic heterogeneity, a system utilizing proteinase K whole cell digests in Western blots was developed. Seventy-two nontypable H. influenzae LOS extracts were analyzed in this Western blot assay. Thirty-seven of these extracts could be segregated into 10 antigenically distinct LOS groups based on immunologic recognition by one or more of the rabbit antisera. Thirty-five of the strains did not contain these LOS antigens. These results demonstrate that antigenic differences exist among the LOS of nontypable H. influenzae strains, and this heterogeneity has the potential to be used to establish an LOS-based serogrouping system.
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PMID:Antigenic diversity of lipooligosaccharides of nontypable Haemophilus influenzae. 354 63

Major outer membrane antigens, proteins, and lipopolysaccharides (LPSs), from nontypable Haemophilus influenzae were characterized and examined as targets for complement-dependent human bactericidal antibodies. Outer membranes from two nontypable H. influenzae isolates that caused otitis media and pneumonia (middle ear and transtracheal aspirates) were prepared by shearing organisms in EDTA. These membranes were compared with membranes prepared independently by spheroplasting and lysozyme treatment of whole cells and found to have: similar sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of the proteins; identical densities (rho = 1.22 g/cm3); and minimal d-lactose dehydrogenase activity indicating purity from cytoplasmic membranes. Outer membranes were solubilized in an LPS-disaggregating buffer and proteins were separated from LPS by molecular sieve chromatography. The SDS-PAGE patterns of outer membrane proteins (OMPs) from the two strains differed in the major band although other prominent bands appeared similar in molecular weight. LPS prepared by hot phenol water extraction of each of the strains contained 45% (pneumonia isolate) and 60% (otitis isolate) lipid (wt/wt), 49% and 50% carbohydrate (wt/wt), respectively, and less than 1%, 3-deoxy-manno octulosonic acid. Immunoglobulin M (IgM) purified from normal human serum (NHS) plus complement was bactericidal for both strains. Purified immunoglobulin G (IgG) from NHS killed the middle ear isolate and immune convalescent IgM from the serum of the patient with pneumonia killed his isolate. NHS or convalescent serum were absorbed with OMPs and LPS (0.6-110 micrograms) from each of the strains and immune specific inhibition of bactericidal antibody activity by each antigen was determined. OMPs from the pulmonary isolate inhibited bactericidal antibody activity directed against the isolate in both NHS (1.5 microgram of antigen) and immune serum (0.75 microgram of antigen). OMPs (60 micrograms) from the ear isolate also inhibited bactericidal activity in the respective immune serum. LPSs exhibited minimal inhibition (greater than 110 micrograms). Three human sera (two normal, one immune) were selectively depleted of 80% of antibody activity against OMPs (measured by enzyme-linked immunosorbent assay) by affinity chromatography using OMPs from the pulmonary isolate coupled to a solid phase. These OMP antibody-depleted sera also showed an 88% reduction of bactericidal activity against this strain. Immunopurified antibody against OMPs eluted from the solid phase was bactericidal.
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PMID:Characterization of antigens from nontypable Haemophilus influenzae recognized by human bactericidal antibodies. Role of Haemophilus outer membrane proteins. 387 75


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