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Infection and Immunity Aug 1987Cryptococcus neoformans var. neoformans (74 isolates) and C. neoformans var. gattii (44 isolates) were used to test urease activity after growth on both yeast...
Cryptococcus neoformans var. neoformans (74 isolates) and C. neoformans var. gattii (44 isolates) were used to test urease activity after growth on both yeast extract-glucose-peptone agar (YEPG) and on YEPG supplemented with 100 microM EDTA. Every isolate grown on YEPG agar for 48 h at 30 degrees C produced a positive reaction within 1 h in a modified rapid urease assay at 37 degrees C. However, isolates grown on YEPG with 100 microM EDTA showed a distinct pattern which corresponded to their varietal status. All but 1 of 74 C. neoformans var. neoformans isolates (98.7%) produced a positive reaction within 1 to 4 h, while none of 44 C. neoformans var. gattii isolates produced a positive reaction within the same period. The urease inhibition results and the canavanine-glycine-bromthymol blue agar test results showed 100% correlation among isolates of C. neoformans var. gattii and 98.7% correlation among isolates of C. neoformans var. neoformans. Two representative isolates of C. neoformans var. gattii (serotypes B and C) were further tested for urease during a prolonged incubation period in urea broth. These isolates failed to show a positive reaction even after 11 h of incubation. The uptake of EDTA was negligible in the two varieties. Extracts of cells grown on YEPA agar showed a high level of urease activity in both varieties. Extracts of cells grown on the agar with 100 microM EDTA showed a marked reduction (86%) of urease activity in one isolate of C. neoformans var. gattii but showed only a 30% reduction in one isolate of C. neoformans var. neoformans. Based on these results, the differential effect of EDTA on the two varieties of C. neoformans appeared to be due to greater inhibition of urease synthesis in C. neoformans var. gattii.
Topics: Cryptococcus; Cryptococcus neoformans; Culture Media; Edetic Acid; Urease
PubMed: 3112009
DOI: 10.1128/iai.55.8.1751-1754.1987 -
Infection Aug 2009A 53-year old immunocompetent Swiss female is described who developed severe meningoencephalitis due to infection with Cryptococcus gattii 13 months following exposure...
A 53-year old immunocompetent Swiss female is described who developed severe meningoencephalitis due to infection with Cryptococcus gattii 13 months following exposure on Vancouver Island, Canada. Diagnosis was based on cerebrospinal fluid (CSF) examination, i.e., positive India-ink staining, positive latex particle agglutination, and positive culture. Species identification was performed by growth on L-canavanine-glycine-bromthymol blue medium and by sequencing of the intergenic and internal transcribed spacer regions of the rRNA genes. After initial therapy with fluconazole by which the patient did not improve, therapy was changed to amphotericin B and flucytosine and later to high-dose fluconazole and amphotericin B. Despite long-term treatment and external drainage of the CSF, the patient's condition improved only slowly. The patient was discharged after 132 days of hospitalization.
Topics: Amphotericin B; Antifungal Agents; Cerebrospinal Fluid; Cryptococcosis; Cryptococcus; Culture Media; DNA, Fungal; DNA, Ribosomal Spacer; Drainage; Female; Fluconazole; Flucytosine; Humans; Meningoencephalitis; Middle Aged; Molecular Sequence Data; Phylogeny; Sequence Analysis, DNA; Switzerland; Travel
PubMed: 19390780
DOI: 10.1007/s15010-008-8211-z -
Journal of Biochemistry Dec 19751. The effects of pH indicators on activities for ATP hydrolysis in the dark and ATP-Pi exchange in the dark were examined with chromatophores from Rhodospirillum...
1. The effects of pH indicators on activities for ATP hydrolysis in the dark and ATP-Pi exchange in the dark were examined with chromatophores from Rhodospirillum rubrum. Of thirty-one pH indicators tested, eleven (metanil yellow, 2, 4-dinitrophenol, ethyl orange, bromocresol green, resazurin, neutral red, bromthymol blue, alpha-naphtholphthalein, o-cresolphthalein, phenolphthalein, and alizarin yellow G) almost completely inhibited the activities for ATP formation and ATP-Pi exchange at concentrations of 1 mM, and were studied in detail. 2. Of the eleven pH indicators, those other than alpha-naptholphthalein, o-cresolphthalein and phenolphthalein, when assayed at appropriate concentrations, inhibited ATP-Pi exchange, but not ATP hydrolysis. In ATP-Pi exchange, these eight pH indicators at the concentrations described above were competitive against Pi, and non-competitive against ATP. The remaining three kinds of pH indicators were non-competitive against either Pi or ATP, when assayed at concentrations of the dyes that inhibited both activities. 3. The amounts of pH indicators bound with chromatophores were measured. No correlation was found between the amounts of the bound dyes and the extents of their inhibition of either ATP formation or ATP-Pi exchange. 4. Ethyl orange (pKa=4.1) and 2, 4-dinitrophenol (pKa=3.9) stimulated ATP hydrolysis to the greatest extent. The latter dye was hardly bound with chromatophores. 5. The stimulatory effects of pH indicators on ATP hydrolysis were hardly affected by extraction of quinones from chromatophores. 6. Most of the pH indicators stimulated both succinate-cytochrome c2 and NADH-cytochrome c2 reductions in the dark. 7. The mechanism of uncoupling of the electron transfer system and the phosphorylation system by pH indicators and the mechanism of the coupling are discussed.
Topics: Adenosine Triphosphate; Bacterial Chromatophores; Binding Sites; Darkness; Hydrogen-Ion Concentration; Indicators and Reagents; Kinetics; Light; Phosphates; Quinones; Rhodospirillum rubrum
PubMed: 5425
DOI: 10.1093/oxfordjournals.jbchem.a131031 -
Journal of Food Protection Mar 2017A modified polymyxin-egg yolk-mannitol-bromothymol blue agar (mPEMBA) was developed by supplementing polymyxin-egg yolk-mannitol-bromothymol blue agar (PEMBA) with...
A modified polymyxin-egg yolk-mannitol-bromothymol blue agar (mPEMBA) was developed by supplementing polymyxin-egg yolk-mannitol-bromothymol blue agar (PEMBA) with trimethoprim to improve the selectivity for and recoverability of Bacillus cereus from naturally and artificially contaminated food samples. The number of B. cereus in mPEMBA was significantly higher than in PEMBA, indicating better recoverability (P < 0.05) in red pepper powder (PEMBA 0.80 ± 0.22 log CFU/g versus mPEMBA 1.95 ± 0.17 log CFU/g) and soybean paste (PEMBA 2.19 ± 0.18 log CFU/g versus mPEMBA 3.09 ± 0.13 log CFU/g). In addition, mPEMBA provided better visual differentiation of B. cereus colonies than PEMBA, which is attributable to the reduced number of competing microflora. We conclude that the addition of trimethoprim to PEMBA could generate a synergistic effect to improve selectivity for B. cereus .
Topics: Agar; Bacillus cereus; Bromthymol Blue; Culture Media; Egg Yolk; Food Microbiology; Mannitol; Polymyxins
PubMed: 28207304
DOI: 10.4315/0362-028X.JFP-16-206 -
Journal of Clinical Microbiology Feb 1978Bromothymol blue (B) broth for the cultivation, detection, and identification of Ureaplasma urealyticum is described. In this medium, strains Cook and 960 had shorter... (Comparative Study)
Comparative Study
Bromothymol blue (B) broth for the cultivation, detection, and identification of Ureaplasma urealyticum is described. In this medium, strains Cook and 960 had shorter generation times (60 min or less) and reached higher populations (over 10(8)) than have yet been reported for this species. Furthermore, the indicator changes color before the end of logarithmic growth, and the cultures retain viability for at least 1 day thereafter, greatly simplifying the handling of the organism. When the populations in cultures of these two strains and seven new isolates were determined, growth was detected earlier and proceeded to higher final titers in B broth than in urease test color medium (U-9 broth). The inclusion of antibiotics in B broth for use in clinical laboratories (B/NL broth) made the medium selective, specific, and more sensitive for the isolation of U. urealyticum. Comparison of B/NL broth with genital mycoplasma (GM) agar and U-9 broth for the primary isolation of U. urealyticum was made with 183 urethral swabs. All 70 isolates were detected on B/NL broth, but only 66 and 63 isolates were detected on GM agar and in U-9 broth, respectively. Moreover, the cultures in B/NL broth were pure and at titers that generally showed good correlation with colony counts on GM agar.
Topics: Bromthymol Blue; Culture Media; Humans; Lincomycin; Male; Species Specificity; Ureaplasma; Urethra
PubMed: 632344
DOI: 10.1128/jcm.7.2.127-132.1978 -
Proceedings of the National Academy of... Oct 1979A pH-indicator dye, bromothymol blue, was used to probe the hydrophilic surface of dimyristoyl-, dipalmitoyl-, and distearoylphosphatidylcholine bilayer vesicles. The...
A pH-indicator dye, bromothymol blue, was used to probe the hydrophilic surface of dimyristoyl-, dipalmitoyl-, and distearoylphosphatidylcholine bilayer vesicles. The apparent pK of the surface-adsorbed dye was larger than the bulk pK value. The contribution of the choline positive charge on the dissociation constant of the dye adsorbed on the vesicle surface was estimated by screening the charge interaction with 2 M KCl. The effective surface potentials interacting with the dye were thus estimated to be 33.2, 45.6, and 46.8 mV, respectively, for the dimyristoyl-, dipalmitoyl-, and distearoylphosphatidylcholine vesicles. From the differences between the obtained effective potentials and the calculated surface potentials of the charge-determining plane of the choline head, the distances between the prototropic part of the dye and the choline charge-determining plane were estimated to be 10.5, 8.0, and 7.8 A, respectively. These values were obtained at 25 degrees C; the dimyristoylphosphatidylcholine membrane was in the liquid-crystalline phase and the other two were in the solid gel phase. Addition of an inhalation anesthetic, enflurane, decreased the distance in the dimyristoylphosphatidylcholine vesicles and increased the distance in the dipalmitoyl- and distearoylphosphatidylcholine vesicles. The increase of precessional motion of choline head by the inhalation anesthetic is apparently responsible for the changes.
Topics: Bromthymol Blue; Enflurane; Hydrogen-Ion Concentration; Mathematics; Membranes, Artificial; Molecular Conformation; Phosphatidylcholines; Surface Properties; Thermodynamics; Thymol
PubMed: 41238
DOI: 10.1073/pnas.76.10.5114 -
Anaesthesia Jan 1996The possibility of using chemical changes to confirm correct tracheal tube placement was investigated with a view to their use in developing countries where more...
The possibility of using chemical changes to confirm correct tracheal tube placement was investigated with a view to their use in developing countries where more sophisticated methods are unavailable. The effect of bubbling expired gases through a 10% solution of bromothymol blue and a 0.25% solution of thiopentone led to chemical changes producing, in the case of bromothymol blue, a colour change and in that of thiopentone, precipitation, probably due to a change in pH caused by carbon dioxide. We also discovered that the time to precipitation of the thiopentone could be greatly reduced if it was mixed with a precise quantity of lignocaine. These simple end points can reliably confirm the correct placement of a tracheal tube at least as rapidly as the correct use of capnography.
Topics: Adult; Bromthymol Blue; Humans; Indicators and Reagents; Intubation, Intratracheal; Lidocaine; Pilot Projects; Thiopental
PubMed: 8669561
DOI: 10.1111/j.1365-2044.1996.tb07649.x -
Journal of Dairy Science May 1985A simple bromothymol blue indicator test was evaluated for farm diagnosis of mastitis. The test required highly absorbent blotting paper impregnated with four spots of...
A simple bromothymol blue indicator test was evaluated for farm diagnosis of mastitis. The test required highly absorbent blotting paper impregnated with four spots of bromothymol blue. Indicator color scores (1 to 4) for quarter foremilks increased with somatic cell count and pH, although variability within each color score was large. Sensitivity of the bromothymol blue test ranged from 51 to 56% and specificity from 89 to 90% for most reference criteria used to classify normal and abnormal milk. Predictability of a positive test ranged from 49 to 52% (false positives 51 to 48%) and predictability of a negative test from 90 to 97% (false negatives 10 to 3%) for the same criteria. Overall the bromothymol blue test incorrectly diagnosed 11 to 20% of 3772 quarters. By classifying color score 2 as negative, predictability of a positive result was 70 to 75% and sensitivity was 26 to 30%. The test can be used by dairy producers to screen herds with a relatively high incidence of mastitis or used in combination with cow cell counts to locate abnormal quarters. The bromothymol blue test was less sensitive than the California Mastitis Test but offered several practical advantages for use on farm.
Topics: Animals; Bromthymol Blue; Cattle; Female; Hydrogen-Ion Concentration; Mastitis, Bovine; Milk; Reagent Strips; Thymol
PubMed: 3842865
DOI: 10.3168/jds.S0022-0302(85)80955-3 -
Analytical Sciences : the International... Sep 2001
Topics: Anti-Allergic Agents; Bromthymol Blue; Coloring Agents; Indicators and Reagents; Pyrogallol; Reproducibility of Results; Spectrophotometry, Ultraviolet; Tablets
PubMed: 11708067
DOI: 10.2116/analsci.17.1101 -
Bulletin of the World Health... 1985A new straightforward photometric method for the assay of the antimalarial drug chloroquine and its metabolites in urine is described. The method involves an ion-pair...
A new straightforward photometric method for the assay of the antimalarial drug chloroquine and its metabolites in urine is described. The method involves an ion-pair extraction procedure with dichloromethane using the acid-base indicator bromthymol blue as counter-ion. The ion pair formed with chloroquine in the organic phase is yellow, and absorbance is measured at lambda = 410 nm using a filter photometer. The absorbance is a linear function of concentration up to 400 mumol/l (120 mg/l) chloroquine. The method is suitable for the determination of chloroquine and its metabolites in urine down to a limiting concentration of about 10 mumol/l (3 mg/l). Additionally, the method is suitable for semiquantitative visual estimation of the concentration of chloroquine in urine. A single dose of 5 mg/kg chloroquine base could be determined in urine from two volunteers for at least 8 days after administration of the drug. The results obtained for the analysis of chloroquine and its metabolites with the colorimetric method described here correlate well with those obtained using high performance liquid chromatography.
Topics: Chloroquine; Chromatography, Liquid; Dose-Response Relationship, Drug; Humans; Spectrophotometry
PubMed: 3879200
DOI: No ID Found