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The Tohoku Journal of Experimental... Sep 1986Electron microscopy of thin sections of Pseudomonas aeruginosa IAM 1007 treated with dibekacin revealed blebs, disintegration of the outer membrane of the cell wall and...
Electron microscopy of thin sections of Pseudomonas aeruginosa IAM 1007 treated with dibekacin revealed blebs, disintegration of the outer membrane of the cell wall and degenerative features of the cytoplasm. In the next experiment, the cell wall fraction was isolated from the mechanically disrupted cells, incubated with dibekacin and was subjected to electron microscopy, in order to find a clue to the action mechanism of dibekacin on the cell wall of Pseudomonas aeruginosa IAM 1007. As a result, it was found that unidentified substances were released from the surface of the cell wall and that the outer membrane of the cell wall disappeared. The degree of changes of the cell wall ultrastructure was almost proportional to the length of incubation with dibekacin. These findings strongly suggest that dibekacin directly disintegrates the outer membrane of the cell wall of Pseudomonas aeruginosa IAM 1007.
Topics: Cell Membrane; Cell Nucleus; Cell Wall; Cytoplasm; Dibekacin; Kanamycin; Microscopy, Electron; Pseudomonas aeruginosa
PubMed: 3095954
DOI: 10.1620/tjem.150.69 -
British Journal of Pharmacology Dec 1985We studied the effect of three aminoglycoside antibiotics which have been shown to replace Ca from lipid monolayers on the superficially bound Ca of isolated beating...
We studied the effect of three aminoglycoside antibiotics which have been shown to replace Ca from lipid monolayers on the superficially bound Ca of isolated beating left atria from guinea-pigs. The cellular Ca content was determined by means of 45Ca after having attained complete exchange. The antibiotics dibekacin, sisomicin, and gentamicin, all reduced the cellular Ca content by 10-20% in a dose-dependent manner. The loss of superficially bound Ca was accompanied by a decline of the contractile force by 40-90%. It is concluded that in isolated atrial muscle it is the amount of Ca bound to the outer surface of the cardiac plasmalemma, rather than the extracellular Ca2+ concentration, that determines contraction height.
Topics: Aminoglycosides; Animals; Anti-Bacterial Agents; Calcium; Depression, Chemical; Dibekacin; Gentamicins; Guinea Pigs; Heart Atria; In Vitro Techniques; Myocardial Contraction; Myocardium; Sisomicin
PubMed: 4075016
DOI: 10.1111/j.1476-5381.1985.tb11101.x -
The Tohoku Journal of Experimental... Nov 1985The enzymatic activity of bacterial beta-glucuronidase plays an essential role in the formation of calcium bilirubinate in bile. There are, however, many unsettled...
The enzymatic activity of bacterial beta-glucuronidase plays an essential role in the formation of calcium bilirubinate in bile. There are, however, many unsettled problems such as methodology of the assay for its enzymatic activity. In the present study (1) the azopigments from monoconjugated bilirubin (MCB) and unconjugated bilirubin (UCB) in native bile were semiquantitatively determined, (2) the deconjugation of conjugated bilirubin (CB) in bile was estimated with azopigment analysis and (3) factors affecting the deconjugation of CB in bile, especially for pH value, were investigated. CB in bile was stable at physiologic pH during 6-hr incubation at 37 degrees C, but was hydrolyzed at alkaline pH. At physiologic pH, addition of beta-glucuronidase from E. coli hydrolyzed CB in bile and increased MCB and UCB in bile. Based upon the results mentioned above, it is suggested that alkaline pH and enzymatic activity of beta-glucuronidase should cause the increase of UCB in bile. It can be said that beta-glucuronidase is essential for the formation of calcium bilirubinate gallstone at physiologic pH.
Topics: Bile; Bile Pigments; Bilirubin; Chemical Phenomena; Chemistry; Dibekacin; Escherichia coli; Gallbladder Diseases; Glucuronidase; Humans; Hydrogen-Ion Concentration; Hydrolysis; In Vitro Techniques
PubMed: 3911493
DOI: 10.1620/tjem.147.281 -
Antimicrobial Agents and Chemotherapy Oct 1985A rapid, simple, and accurate method for the determination of kanamycin and dibekacin in serum by use of high-pressure liquid chromatography is described. The serum...
A rapid, simple, and accurate method for the determination of kanamycin and dibekacin in serum by use of high-pressure liquid chromatography is described. The serum proteins were precipitated with 3.5% perchloric acid containing sodium octanesulfonate. After centrifugation, a sample of the supernatant was directly injected into the chromatograph. The determination of kanamycin and dibekacin was performed by a combination of reverse-phase, ion-pair chromatography, postcolumn derivatization with o-phthalaldehyde, and fluorescence detection. The correlation coefficients with fluorescence polarization immunoassay were 0.996 for kanamycin and 0.957 for dibekacin.
Topics: Chromatography, High Pressure Liquid; Dibekacin; Humans; Kanamycin; Spectrometry, Fluorescence
PubMed: 4073874
DOI: 10.1128/AAC.28.4.521 -
Antimicrobial Agents and Chemotherapy Aug 1985The resistance mechanisms of more than 2,000 aminoglycoside-resistant gram-negative aerobic bacteria were estimated by a method that assigned a biochemical mechanism...
The resistance mechanisms of more than 2,000 aminoglycoside-resistant gram-negative aerobic bacteria were estimated by a method that assigned a biochemical mechanism based on susceptibility to selected aminoglycosides. Strains from hospitals in Japan, Formosa, and Korea (the Far East) were compared with strains from Chile and the United States. Of the strains from Chile, 90% had an aminoglycoside resistance pattern indicative of the 3-N-acetyltransferase [AAC(3)-V] enzyme. Of the strains from the Far East, 78% had susceptibility patterns suggesting the presence of AAC(6') enzymes. In contrast, strains from the United States had a wider variety of resistance mechanisms including 2''-O-adenylyltidyltransferase [ANT(2'')], AAC(3), AAC(6'), and AAC(2'). Reflecting these differences in resistance patterns, the frequencies of resistance to gentamicin, tobramycin, dibekacin, and amikacin in strains from the United States were different from those in strains from the Far East. These differences seem to be correlated with different aminoglycoside usage in the two regions. In the United States, where gentamicin was the most widely used aminoglycoside, 92% of the strains were resistant to gentamicin, 81% were resistant to dibekacin, and 8.8% were resistant to amikacin. In the Far East, dibekacin and kanamycin were widely used in the past and more recently amikacin has been frequently used. Of the strains from this region, 99% were resistant to dibekacin, 85% were resistant to gentamicin, and 35% were resistant to amikacin.
Topics: Aminoglycosides; Anti-Bacterial Agents; Chile; Drug Resistance, Microbial; Gram-Negative Bacteria; Humans; Japan; Korea; Microbial Sensitivity Tests; Proteus vulgaris; Providencia; Pseudomonas; Serratia; Taiwan; United States
PubMed: 3914858
DOI: 10.1128/AAC.28.2.282 -
Antimicrobial Agents and Chemotherapy Apr 1985The tubular disposition of five aminoglycosides was studied in humans to establish a possible relationship between tubular reabsorption and the nephrotoxicity that has... (Comparative Study)
Comparative Study
The tubular disposition of five aminoglycosides was studied in humans to establish a possible relationship between tubular reabsorption and the nephrotoxicity that has been described in the literature. Thirty-three healthy male volunteers received a continuous intravenous infusion of isotonic saline with inulin, followed 1 h later by inulin plus gentamicin, dibekacin, tobramycin, netilmicin, or amikacin (1 mg/kg per h) or amikacin (4 mg/kg per h) over a period of 2 h. Brain-stem-evoked response audiometry was performed both before and at the end of each infusion. The latency of wave V remained constant whichever antibiotic was considered. The glomerular filtration rate did not vary significantly during the infusion of each drug. The percent fractional excretion was 79 +/- 6, 81 +/- 22, 85 +/- 5, and 99 +/- 9 for gentamicin, dibekacin, tobramycin, and netilmicin, respectively, and 83 +/- 4 and 124 +/- 13 for amikacin at concentrations of 1 and 4 mg/kg per h, respectively. Net balance and renal clearance were similar for the five aminoglycosides when administered at a rate of 1 mg/kg per h. With gentamicin only, fractional excretion was correlated with the urinary flow rate. We can conclude that (i) gentamicin, generally considered the most nephrotoxic agent, had the highest degree of net reabsorption; (ii) netilmicin exhibited a net zero tubular balance; (iii) amikacin had different patterns of tubular disposition according to the dose, i.e., reabsorption at 1 mg/kg per h and secretion at 4 mg/kg per h, raising the hypothesis of a saturable process of reabsorption; and (iv) these differences in tubular reabsorption could account at least in part for the known different nephrotoxic potentials of these five aminoglycosides in humans.
Topics: Adult; Amikacin; Aminoglycosides; Anti-Bacterial Agents; Blood Proteins; Dibekacin; Electrolytes; Gentamicins; Glomerular Filtration Rate; Humans; Kidney Tubules; L-Lactate Dehydrogenase; Male; Netilmicin; Protein Binding; Tobramycin
PubMed: 4004192
DOI: 10.1128/AAC.27.4.520 -
Hinyokika Kiyo. Acta Urologica Japonica Dec 1984We have clinically surveyed the distribution and disk sensitivity of bacterial strains obtained from urine of patients with various urological disease at our department...
We have clinically surveyed the distribution and disk sensitivity of bacterial strains obtained from urine of patients with various urological disease at our department during three (1975-1977) and four (1980-1983) years. Escherichia coli was the most frequently isolated (29.4%) from the outpatients, followed by Staphylococcus epidermidis (17.5%), Pseudomonas cepacia (11.2%) and Serratia marcescens (11.2%). Pseudomonas cepacia was the most frequently isolated (28.0%) from the inpatients, followed by Staphylococcus epidermidis (16.3%) and Serratia marcescens (15.9%). Pseudomonas cepacia which has been increasing was first isolated in 1977 and Serratia marcescens in 1976. They have become the main bacteria causing infections in our hospital. Pseudomonas cepacia was frequently isolated after postoperative prophylactic chemotherapy and Serratia marcescens in the late period of admission. The majority of Pseudomonas cepacia was resistant to all agents except chloramphenicol and doxycycline. Serratia marcescens was also resistant except to gentamicin and doxycycline. In Escherichia coli species, resistant strains increased gradually but they have good sensitivity to gentamicin, dibekacin, colistin and doxycycline. Staphylococcus epidermidis isolated from outpatients had good sensitivity to all agents but increased in incidence of resistant strains isolated from inpatients.
Topics: Anti-Bacterial Agents; Bacteria; Drug Resistance, Microbial; Humans; Inpatients; Japan; Outpatients; Urine; Urologic Diseases
PubMed: 6532215
DOI: No ID Found -
Antimicrobial Agents and Chemotherapy Dec 1984We developed a rapid, quantitative culture method to estimate the replication of Mycobacterium avium-intracellulare complex (MAIC) in human peripheral blood mononuclear...
We developed a rapid, quantitative culture method to estimate the replication of Mycobacterium avium-intracellulare complex (MAIC) in human peripheral blood mononuclear cells. Mononuclear cells were plated in a 96-well tray, infected with clinically isolated strains of MAIC in the presence of autologous plasma, and further cultivated for 1 to 2 weeks in a tissue culture medium. No MAIC cells proliferated extracellularly, since human plasma inhibited extracellular growth of the mycobacteria. The mononuclear cells were lysed through a brief treatment with alkali, and surviving intracellular mycobacteria were diluted and plated with tissue culture medium in a 96-well tray. Mycobacterial colonies were counted under a microscope after a 5-day incubation. The number of viable MAIC cells continuously increased, reaching 10 times the number of inoculated cells in a week. Thus, mononuclear phagocytes were the permissive site for the replication of MAIC. Intra- and extracellular susceptibilities of seven MAIC strains to four aminoglycoside antibiotics were then studied. The mycobacteria were most susceptible in vitro to dibekacin (MICs, 3.13 to 12.5 micrograms/ml). Dibekacin at 12.5 micrograms/ml was bacteriostatic to five of seven strains in the monocytes. Also, intracellular replication of the other two strains was greatly suppressed by that concentration of dibekacin.
Topics: Aminoglycosides; Anti-Bacterial Agents; Blood Bactericidal Activity; Cell Division; Humans; In Vitro Techniques; Kinetics; Microbial Sensitivity Tests; Monocytes; Mycobacterium; Mycobacterium avium; Phagocytes
PubMed: 6524901
DOI: 10.1128/AAC.26.6.841 -
Antimicrobial Agents and Chemotherapy Aug 1984The antibacterial activities of K-4619 (3-de-O-methylsporaricin A sulfate) were compared with those of sporaricin A, amikacin, dibekacin, and gentamicin. K-4619...
The antibacterial activities of K-4619 (3-de-O-methylsporaricin A sulfate) were compared with those of sporaricin A, amikacin, dibekacin, and gentamicin. K-4619 exhibited a high order of activity against gram-positive and gram-negative bacteria, including Pseudomonas aeruginosa. Its activity against Providencia species and Serratia marcescens was the highest of all drugs tested. K-4619 was highly effective against bacteria that produce various aminoglycoside-inactivating enzymes, except for 3-acetyltransferase I. The bactericidal activity of K-4619 was somewhat greater than that of amikacin. The activity of K-4619 against gram-negative bacteria increased at alkaline pH and was hardly affected by inoculum size, addition of horse serum, and composition of the medium. The in vivo protective effect of K-4619 against infections with Klebsiella pneumoniae, S. marcescens, and P. aeruginosa in mice was greater than that of sporaricin A. K-4619 was also active in mice infected with gentamicin- or amikacin-resistant strains bearing some of the aminoglycoside-inactivating enzymes.
Topics: Amikacin; Aminoglycosides; Animals; Anti-Bacterial Agents; Bacteria; Bacterial Infections; Chromatography, Thin Layer; Culture Media; Dibekacin; Drug Resistance, Microbial; Gentamicins; Hydrogen-Ion Concentration; Male; Mice; Mice, Inbred ICR; Microbial Sensitivity Tests
PubMed: 6548350
DOI: 10.1128/AAC.26.2.187 -
Journal of Clinical Microbiology Aug 1984Approximately 40% of Escherichia coli strains isolated from clinical specimens at the Institute of Medical Microbiology of the University of Zurich were resistant to...
Approximately 40% of Escherichia coli strains isolated from clinical specimens at the Institute of Medical Microbiology of the University of Zurich were resistant to kanamycin but susceptible to tobramycin in disk diffusion tests. Whereas 50% of these strains required a MIC of 7 micrograms of tobramycin per ml to inhibit 1 x 10(5) to 4 x 10(5) cells, 20% of them required a concentration of 8 micrograms or more of the drug per ml. The disk diffusion test, therefore, failed to detect resistance to tobramycin in kanamycin-resistant E. coli strains. Cell extracts from two representative strains phosphorylated and inactivated kanamycin, amikacin, gentamicin, tobramycin, 3',4'-dideoxykanamycin B (dibekacin), butirosin, lividomycin,and ribostamycin, which together constituted a novel spectrum of substrates for the enzymatic activity.
Topics: Aminoglycosides; Anti-Bacterial Agents; Drug Resistance, Microbial; Escherichia coli; Kanamycin; Kanamycin Kinase; Microbial Sensitivity Tests; Phosphorylation; Phosphotransferases; Tobramycin
PubMed: 6092419
DOI: 10.1128/jcm.20.2.295-297.1984