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

The composition of the membrane-bound electron transport system of Haemophilus parainfluenzae underwent modification in response to the terminal electron acceptor in the growth medium. H. parainfluenzae was able to grow with O(2), nitrate, fumarate, pyruvate, and substrate amounts of nicotinamide adenine dinucleotide (NAD) as electron acceptors. When O(2) served as the electron acceptor and its concentration was lowered below 20 mum, the bacteria formed more cytochromes b, c, a(1), a(2), and o than were present in the cells grown at 150 to 200 mum O(2). Nitrate and nitrite reductase activities also appeared during growth at the low O(2) concentrations in the absence of added nitrate. Cytochrome levels in cells grown anaerobically with fumarate, pyruvate, or NAD as terminal acceptors were similar to those formed in cells grown at low O(2) concentrations. Cells grown with nitrate had higher levels of cytochromes c, b, and o, and of nitrate and nitrite reductases, than did cells grown with the other acceptors. The formation of cytochrome oxidase a(2) was repressed by the presence of nitrate in the growth medium. The critical O(2) concentration (the O(2) concentration at which the rate of O(2) uptake becomes demonstrably dependent on the O(2) concentration) was about 100 mum in cells grown with nitrate and about 15 mum in cells grown with the other acceptors. A mutant of H. parainfluenzae was found to make about 10% as much cytochrome c as the wild type, and its formation of cytochrome a(2) was not repressed by nitrate. The critical O(2) concentration of the mutant was high when it was grown with nitrate, suggesting that the high levels of cytochrome c and the absence of cytochrome a(2) from the wild type are not responsible for the high critical O(2) concentration. The modifications of the respiratory system induced by changing the terminal electron acceptor were inhibited by the presence of chloramphenicol, which suggests that protein synthesis is involved.
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PMID:Effect of nitrate, fumarate, and oxygen on the formation of the membrane-bound electron transport system of Haemophilus parainfluenzae. 431 51

A procedure has been developed for isolating mutants which are defective with respect to nicotinamide adenine dinucleotide (NAD) metabolism. It is based on the well known V-factor requirement of Haemophilus parainfluenzae. This procedure was used to isolate a series of mutants from Escherichia coli. The pyridine metabolism of wild-type and mutant E. coli cells falls in one of four distinct classes. Class A includes wild-type E. coli and represents strains that are normal with respect to pyridine metabolism. Class B mutants have altered internal pools of NAD. The intracellular NAD concentration of different class B mutants varies over a 10-fold range. Class C mutants excrete pyridine mononucleotides, and class D mutants excrete NAD. The production of pyridine nucleotides by class C and D mutants exceeds that of wild-type E. coli by a factor of at least ten. The mutant strains generally have normal generation times and achieve normal cell densities in minimal medium.
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PMID:Method for isolating mutants overproducing nicotinamide adenine dinucleotide and its precursors. 433 79

Metabolic factors that suppress development of competence in Haemophilus influenzae during growth in the synthetic medium MI(c) have been identified. These include inosine, nicotinamide adenine dinucleotide, glycerol, and uracil. It is also possible to initiate competence in the presence of these substances if the oxygen tension in the culture is temporarily reduced.
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PMID:Identification of competence-repressing factors during log-phase growth of Haemophilus influenzae. 433 8

Spencer, Hugh T. (The Johns Hopkins University School of Hygiene and Public Health, Baltimore, Md.), and Roger M. Herriott. Development of competence of Haemophilus influenzae. J. Bacteriol. 90:911-920. 1965.-A chemically defined nongrowth medium was developed for the induction of competence of Haemophilus influenzae by a stepdown procedure. Cells grown logarithmically in Heart Infusion Broth became competent after being transferred to a medium which consisted of amino acids, sodium fumarate, and inorganic salts. Chloramphenicol (2 mug/ml) or l-valine (1 mug/ml) in the nongrowth medium inhibited development of competence. The inhibitory action of l-valine was reversed by comparable concentrations of l-isoleucine. Kinetic studies of the development of competence showed a variable capacity of competent cells to take up deoxyribonucleic acid and reaffirmed earlier findings that competence was not transmissible in H. influenzae. Addition of nicotinamide adenine dinucleotide, thiamine, calcium pantothenate, uracil, and hypoxanthine to the medium for competence resulted in a minimal growth medium in which reduced levels of competence were developed.
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PMID:Development of competence of Haemophilus influenzae. 529 17

Crystal violet, lincomycin, spectinomycin and bacitracin were evaluated as selective agents in media for isolation of Haemophilus pleuropneumoniae. No single antimicrobial agent or combination of two or more inhibited all non-Haemophilus strains (Escherichia coli, Pasteurella haemolytica, Pasteurella multocida, Streptococcus faecalis, Streptococcus equisimilis and Staphylococcus aureus) without marked suppression of 16 H. pleuropneumoniae strains. A medium containing 1 micrograms/mL of crystal violet, 1 microgram/mL of lincomycin, 8 micrograms/mL of spectinomycin and 128 micrograms/mL of bacitracin inhibited one E. coli strain and the Gram-positive strains while H. pleuropneumoniae strains were suppressed to a minor degree only. Haemophilus pleuropneumoniae was isolated on the selective medium on three occasions from the nose or pharynx of two out of eight experimentally inoculated pigs. Haemophilus pleuropneumoniae was recovered from the nose of only two pigs at necropsy and from tonsil of one, whereas the lower airways in most pigs and the lung lesions in all pigs were positive. There was no advantage to using the selective medium for the recovery of H. pleuropneumoniae at necropsy from these eight experimentally infected pigs, probably because other bacteria were absent or present in very low numbers in the tissues with H. pleuropneumoniae. The isolation rate on selective medium was higher than the rate on non-selective medium (p less than or equal to 0.1; chi 2 test) when the airways of slaughtered pigs were cultured. This was likely due to a high degree of contamination. Dry swabs placed in tryptone yeast extract with nicotinamide-adenine-dinucleotide gave a significantly higher recovery rate than commercial Culturette swabs in modified Stuart's transport medium.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Evaluation of a selective medium for isolation of Haemophilus pleuropneumoniae. 623 Jan 43

One hundred Haemophilus influenzae isolates from various body sites were biotyped by conventional methods and by the API 20E system (Analytab Products, Plainview, N.Y.). By using a hemin- and a nicotinamide adenine dinucleotide-enriched saline solution as the inoculating fluid for the API 20E, a 100% correlation of results was obtained between the two methods. Ninety percent of the blood and cerebrospinal fluid isolates were biotype I. Biotype II was the predominant biotype encountered overall. No correlation was observed between beta-lactamase production and biotype. The API 20E is a reliable method and should prove useful for routine biotyping of H. influenzae in the clinical laboratory.
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PMID:Novel method of biotyping Haemophilus influenzae that uses API 20e. 705 Jan 51

The effect of a commercially available, chemically defined enrichment (Iso-VitaleX; BBL Microbiology Systems, Cockeysville, Md.) on the growth of 10 strains of Haemophilus somnus was studied. A 6- to 10-fold increase in growth, as measured turbidimetrically, was observed when Iso VitaleX was added to a basal medium of brain heart infusion broth to a final concentration of 1% (vol/vol). Thiamine pyrophosphate (cocarboxylase), a constituent component of Iso VitaleX, was found to be the only growth-promoting factor, and it could be used as a substitute for Iso VitaleX. An equimolar concentration (2.2 microM) of thiamine monophosphate promoted growth equal to that of thiamine pyrophosphate. Thiamine was nonstimulatory for all 10 strains tested. When alkaline thermal-treated brain heart infusion broth was used as the basal medium, 7 of the 10 strains had an absolute requirement for thiamine monophosphate or thiamine pyrophosphate. The three remaining strains showed minimal growth when thiamine was added to this basal medium; however, excellent growth was observed when thiamine monophosphate or thiamine pyrophosphate was utilized. Factor X (hemin) was found to further enhance the growth when concentrations of 5 to 10 micrograms/ml were coupled with thiamine pyrophosphate. No increase in growth was observed when factor V (nicotinamide adenine dinucleotide) was coupled with thiamine pyrophosphate. This is the first report of a growth factor requirement for H. somnus.
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PMID:Thiamine pyrophosphate (cocarboxylase) as a growth factor for Haemophilus somnus. 727 48

In South Africa from early 1989 onward, strains of Haemophilus paragallinarum not requiring nicotinamide adenine dinucleotide (NAD) have been isolated from commercial chickens suffering from infectious coryza. Fifteen of these field isolates were characterized by biochemical typing, serotyping, restriction endonuclease analysis (REA), and ribotyping. The chosen isolates represented diversity in geographic location, time of disease outbreak, and type of flock. All were typical of the species in biochemical properties, except that they were NAD-independent, and all were Page serovar A. REA was performed with three enzymes: HindIII, HpaII, and SspI. All isolates gave identical REA profiles with all three enzymes. Ribotyping was performed using a probe that consisted of the plasmid pUC19 into which the 16S rRNA operon of H. paragallinarum had been inserted. All 15 isolates gave the same ribotyping profile using each of the three enzymes. As a group, the NAD-independent strains gave REA profiles and ribotypes that were very different from a range of classic South African strains isolated before 1989. Our results strongly suggest that the NAD-independent isolates are clonal in nature.
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PMID:Phenotypic and molecular characterization of V-factor (NAD)-independent haemophilus paragallinarum. 767 50

Haemophilus influenzae is a V factor-dependent species. A plasmid conferring V factor independence in Haemophilus parainfluenzae and Haemophilus ducreyi was transferred to plasmid-free H. influenzae Rd by DNA transformation. The growth characteristics of the transformants in a complex and a chemically defined medium were compared, and the ability of several exogenous pyridine nucleotides and precursors to support growth was examined. Although the transformants appeared to be V factor independent in a complex medium, in a chemically defined medium they exhibited both V factor-dependent and nicotinamide-dependent growth. Because of the inability of the plasmid-free H. influenzae Rd to utilize nicotinamide for growth, it was concluded that the genes conferring this function were plasmid linked. Our results indicate that the V factor requirement, as it is presently defined, is not suitable to serve as a definitive taxonomic criterion for species determination in the family Pasteurellaceae.
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PMID:Growth characteristics of V factor-independent transformants of Haemophilus influenzae. 824 Sep 60

Haemophilus test medium (HTM) was compared with Wilkins-Chalgren agar (WCA; supplemented with 15 micrograms/ml nicotinamide adenine dinucleotide (NAD)) for antibiotic susceptibility testing of 74 clinical isolates of Haemophilus influenzae and Haemophilus parainfluenzae. The Bauer-Kirby agar disk diffusion method and the agar dilution procedure were the two tests employed. WCA + NAD and HTM yielded comparable results for the following antimicrobial drugs and drug combinations: ampicillin, amoxicillin plus clavulanic acid, ampicillin plus sulbactam, cefotaxime, cefuroxime, chloramphenicol, ciprofloxacin, and doxycycline. However, WCA + NAD slightly antagonized rifampin. Co-trimoxazole was significantly antagonized by WCA + NAD. WCA + NAD was much simpler with regard to in-house preparation, and WCA plates could be supplemented with NAD following pouring, solidification and storage of the plates simply by surface spreading the required amount of NAD with a glass spatula, thus adding considerably to laboratory flexibility. It is suggested that additional laboratories comparatively and critically examine WCA + NAD medium for antibiotic susceptibility testing of clinical Haemophilus isolates.
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PMID:Comparison of Wilkins-Chalgren medium supplemented with nicotinamide adenine dinucleotide and Haemophilus test medium for susceptibility testing of clinical Haemophilus isolates. 852 34


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