Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Gram-negative bacterium Haemophilus influenzae has been shown to cause a deterioration of the guinea pig pulmonary beta-adrenergic receptor system. In the present study we investigated further the mechanisms behind this effect. To this extent we evaluated the involvement of pulmonary macrophages (PM). Treatment of guinea pigs with killed H. influenzae bacteria resulted in the accumulation of a factor in the serum which could specifically stimulate PM. Thus stimulated, PM from nontreated animals caused a decrease of tracheal beta-adrenergic receptor function in vitro. This effect was evident by a decrease of the maximal response of the dose-response curves to isoprenaline, whereas the EC50 values did not change. Catalase and thiourea abolished the PM-induced effects, whereas superoxide dismutase did not, indicating that oxygen-centered radicals, in particular the highly reactive hydroxyl radical, may be responsible for the observed effects. In addition, dexamethasone also inhibited the decrease of tracheal beta-adrenergic receptor function. When activated PM, taken from animals that had been pretreated with killed H. influenzae bacteria 4 days beforehand, were stimulated with serum from a H. influenzae-treated animal, a potentiation of tracheal beta-adrenergic receptor function was observed.
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PMID:Dual effects of Haemophilus influenzae on guinea pig tracheal beta-adrenergic receptor function: involvement of oxygen-centered radicals from pulmonary macrophages. 303 75

Bactericidal effects of polyunsaturated fatty acids were investigated by using an in vitro killing assay. All gram-positive species tested were extremely susceptible to 10(-5) M arachidonic acid as were Neisseria, Branhamella, and Haemophilus spp. Pseudomonas aeruginosa and and members of the Enterobacteriaceae were resistant. The toxicity of polyunsaturated fatty acids for Staphylococcus aureus was dependent upon time, concentration, and fatty acid unsaturation. Arachidonic acid underwent peroxidation when incubated with S. aureus, but arachidonic acid peroxidation products had low bactericidal activity. Catalase protected S. aureus, whereas superoxide dismutase was ineffective. Scavengers of hydroxyl radicals or singlet oxygen or removal of halide ions had little effect on arachidonic acid-induced killing of bacteria, whereas transition metal chelators and some thiols were highly protective. S. aureus grown in iron-supplemented broth had increased iron content and arachidonic acid susceptibility. Ascorbate also potentiated arachidonic acid-induced killing of S. aureus. These observations indicate that bactericidal effects of polyunsaturated fatty acids are mediated by a peroxidative process involving H2O2 and bacterial iron.
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PMID:Bactericidal effects of polyunsaturated fatty acids. 308 65

Actinobacillus actinomycetemcomitans and the genetically-related oral haemophili (Haemophilus segnis, Haemophilus aprhophilus and Haemophilus paraphrophilus) exhibit a range of sensitivities to the lethal effect of hydrogen peroxide (H2O2), A. actinomycetemcomitans being the most resistant. To extend this information, susceptibility to a range of H2O2 concentrations (10(-6)-10(-3) M) was assessed by incubating bacterial suspensions for 1 h at 37 degrees C in the presence of H2O2 and spreading the suspensions on chocolate agar plates to determine the concentration of H2O2 producing a 50 per cent reduction in colony-forming units (LD50). Catalase activity was quantified with a Clark-type oxygen electrode, which polarographically monitored the formation of dissolved oxygen in bacterial suspensions or sonicates following addition of reagent H2O2. Sensitivity to H2O2 did not correlate with catalase activity, either in intact cells or in bacterial sonicates. Specifically, some bacterial strains with undetectable catalase activity were highly resistant to H2O2. Micromolar concentrations of sodium azide which completely inhibited cell-associated catalase activity did not affect the resistance of A. actinomycetemcomitans to H2O2. Thus, the endogenous catalase activity of A. actinomycetemcomitans and certain oral haemophili is not an important determinant of resistance to the bactericidal effects of H2O2.
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PMID:Influence of endogenous catalase activity on the sensitivity of the oral bacterium Actinobacillus actinomycetemcomitans and the oral haemophili to the bactericidal properties of hydrogen peroxide. 386 73

The catalase gene, katA, of the sepiolid squid symbiont Vibrio fischeri has been cloned and sequenced. The predicted amino acid sequence of KatA has a high degree of similarity to the recently defined group III catalases, including those found in Haemophilus influenzae, Bacteroides fragilis, and Proteus mirabilis. Upstream of the predicted start codon of katA is a sequence that closely matches the consensus sequence for promoters regulated in Escherichia coli by the alternative sigma factor encoded by rpoS. Further, the level of expression of the cloned katA gene in an E. coli rpoS mutant is much lower than in wild-type E. coli. Catalase activity is induced three- to fourfold both as growing V. fischeri cells approach stationary phase and upon the addition of a small amount of hydrogen peroxide during logarithmic growth. The catalase activity was localized in the periplasm of wild-type V. fischeri cells, where its role could be to detoxify hydrogen peroxide coming from the external environment. No significant catalase activity could be detected in a katA null mutant strain, demonstrating that KatA is the predominately expressed catalase in V. fischeri and indicating that V. fischeri carries only a single catalase gene. The catalase mutant was defective in its ability to competitively colonize the light organs of juvenile squids in coinoculation experiments with the parent strain, suggesting that the catalase enzyme plays an important role in the symbiosis between V. fischeri and its squid host.
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PMID:The periplasmic, group III catalase of Vibrio fischeri is required for normal symbiotic competence and is induced both by oxidative stress and by approach to stationary phase. 955 90

White, D. C. (Rockefeller Institute, New York, N.Y.). Respiratory systems in hemin-requiring Haemophilus species. J. Bacteriol. 85:84-96. 1963.-If grown in Levinthal's medium or in proteose peptone medium with excess hemin, Haemophilus influenzae, H. aegyptius, and H. canis (H. haemoglobinophilus) form an electron-transport system consisting of six cytochromes and two respiratory flavoproteins. In proteose peptone, these species can greatly modify the composition of their electron-transport complex. With anaerobic incubation in the presence of nitrate, they produce increased amounts of cytochrome c(1) and the cytochrome oxidases a(1) and o. This anaerobic pattern is greatly exaggerated by growth under carbon monoxide, in which case large concentrations of cytochrome oxidase are produced. In the presence of the inhibitor secobarbital or of growth-limiting amounts of hemin, intermediate amounts of cytochromes and respiratory flavoproteins are formed. When only small amounts of hemin are present, these species grow but form no detectable cytochrome system. Catalase is the only hemoprotein found. Under these conditions, the addition of glucose induces the formation of a lactate oxidase flavoprotein if the system is incubated aerobically. This cytochromeless state also occurs when these species are grown in KCN or anaerobically without nitrate and with excess hemin. The ability of these species to modify the composition of the electron-transport system strongly suggests that this function unit is formed from individual components. Hemin-requiring Haemophilus species have a hemin-sparing compensatory mechanism that allows growth under conditions under which hemin-independent Haemophilus species will not grow.
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PMID:Respiratory systems in the hemin-requiring Haemophilus species. 1400 Feb 93

Meningococcal conjunctivitis is a rare but important infection since it can lead to severe complications and can threaten public health. It may emerge in two forms, either primary or secondary type which is developed after a systemic infection. Accurate diagnosis of primary meningococcal conjunctivitis is very important in addition to ocular complications which can result in loss of vision, the condition can also lead to severe complications like systemic meningococcal disease. However, the lack of specific symptoms which can distinguish meningococcal conjunctivitis from other forms of bacterial conjunctivitis, initiation of empiric antibiotic therapy without performing culture and nonaccurate differentiation of Neisseria gonorrhoeae and Neisseria meningitidis with commercial kits/systems used in laboratories cause problematic situations. This report describes a case of primary unilateral conjunctivitis in a 14-month-old girl caused by non-groupable N.meningitidis that was resolved without sequelae following treatment. A pre-healthy 14-month-old girl was brought to the pediatric emergency department with redness, crusts and discharge in the left eye that had begun two days earlier. Ocular examination revealed hyperemia and purulent discharge in the left conjunctiva. Purulent conjunctivitis was diagnosed. A conjunctival swab specimen was taken for culture, and the patient was started on topical netilmicin (4x1), topical fusidic acid (2x1) and artificial tears. Microscopic examination of the conjunctival swab revealed polymorphonuclear leukocytes and no visible bacteria. Catalase and oxidase positive, gram-negative diplococci grew purely in culture. The first Gram stain preparation was evaluated again after the growth and small numbers of gram-negative diplococci were observed. The cultivated bacteria were identified as N.meningitidis using MALDI-TOF MS (Bruker Daltonics, Germany), but as N.gonorrhoeae with BBL Crystal N/H (Neisseria/Haemophilus) (BD Diagnostic Systems, MD) identification system. The isolate was identified as N.meningitidis by polymerase chain reaction method. The isolate was sent to the Public Health Institution of Turkey for confirmation and serotyping. It was confirmed as non-groupable N.meningitidis. This is the first report of conjunctivitis caused by non-groupable N.meningitidis from Turkey. We wish to emphasize the importance of Gram staining and differentiation of the species by automatized systems in diagnosis, netilmicin may be one of the options for empiric treatment and in terms of public health the most appropriate approach may be evaluation of the severity of conjunctivitis and causative serogroup which depends on case-based approach.
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PMID:[Primary Neisseria meningitidis conjunctivitis in a 14-month-old child]. 2631 89