Differentiation between Mycobacterium avium and M. intracellulare by phenetic characteristics.
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DNA Probes↗
Biomedical subjects
S Yamori
Publications and source records attributed to S Yamori.
Paradoxical effect of Tween 80 between the susceptibility to rifampicin and streptomycin and the susceptibility to ethambutol and sulfadimethoxine in the Mycobacterium avium-Mycobacterium intracellulare complex.
The susceptibility to rifampicin and streptomycin of the Mycobacterium avium-Mycobacterium intracellulare complex was augmented by the addition of Tween 80 into 7H10 agar medium with OADC, whereas the susceptibility to ethambutol and sulfadimethoxine was either not changed or reduced by the addition of Tween 80. In 7H10 agar medium without OADC, however, susceptibilities to both rifampicin and sulfadimethoxine were reduced by the addition of Tween 80 to the medium. A number of hypotheses are made to explain these phenomena.
Antitubercular Agents↗
[Change in biochemical and biological characteristics of Mycobacterium tuberculosis strains isolated in recent years].
One hundred strains of Mycobacterium tuberculosis isolated in 1988-89 from patients who were newly hospitalized in the National Chubu Hospital were studied on their biochemical and biological characteristics and compared with the strains isolated previously. Recently isolated strains showed frequently a much stronger arylsulfatase activity, grew at a higher rate at 42 degrees C, and showed a little stronger niacin production.
Drug Resistance, Microbial↗
[Chemotherapeutic regimens for nontuberculous mycobacterial infection based on in-vitro susceptibility test results].
Treatment of nontuberculous mycobacterial infection should be carried out by the chemotherapeutic regimens most suitable for each species. We performed in-vitro susceptibility tests for various species and determined the probability in which the mycobacteria of each species are inhibited by blood concentrations attainable by the dosages usually used. From such determinations, the following regimens have been recommended: 1) M. avium-M. intracellulare complex, Rifampicin + Enviomycin + Ethambutol; 2) M. kansasii, Ofloxacin + Enviomycin + Rifampicin; 3) M. szulgai, Enviomycin - Ethambutol + Isoniazid; 4) M. fortuitum, Ofloxacin. The effectiveness of the treatment of the infection caused by M. avium complex is less than 15% even using the above regimen, while it is high in the treatment of infections caused by M. kansasii and M. szulgai. There are no effective regimens for the treatment of infection caused by M. chelonae or M. simiae. The above recommendations are useful in practice, because, at present, reliable susceptibility testing of nontuberculous mycobacteria is not yet done commonly.
Drug Resistance, Microbial↗
[Bactericidal activities of rifampicin, ethambutol, enviomycin and streptomycin on Mycobacterium avium-Mycobacterium intracellulare complex strains].
Bacteriostatic and bactericidal activities of rifampicin, ethambutol, enviomycin and streptomycin on Mycobacterium avium-Mycobacterium intracellulare complex (MAI complex) strains were determined. The susceptibility testings were made in Ogawa egg medium, and minimal inhibitory concentrations (MICs) were determined as the lowest concentration of drugs, in which the growth of 20 to 100 colony-forming units was completely inhibited. The MICs correspond to the MICs that can inhibit the growth of 95 to 99% of bacterial population. Bactericidal activity was determined in a modified Dubos liquid medium (1.3 g of Dubos TB Broth Base were dissolved in 180 ml of distilled water and this solution was supplemented by 20 ml of bovine serum). A one ml-sample of bacterial suspensions (10 mg wet weight per ml) was added to 9 ml of the Dubos liquid medium, and the medium was incubated at 37 degrees C for 0, 1, 3 and 7 days under shaking condition (56 strokes per minute; 8 cm amplitude). The bactericidal activity was measured as the number of colony-forming units contained in a 0.02 ml-sample of the medium. The bactericidal activities of rifampicin and ethambutol were weak or absent even in strains 13008 and 13016, which were very susceptible to all four drugs. However, the bactericidal activities of streptomycin and enviomycin could be observed in these strains.(ABSTRACT TRUNCATED AT 250 WORDS)
Antitubercular Agents↗
[In-vitro susceptibility of Mycobacterium avium complex to isoniazid and ethionamide].
In this study, it was investigated whether or not Mycobacterium avium complex strains were inhibited by such low concentrations of isoniazid and ethionamide as possible in blood. The inhibitory concentrations were determined by the "Actual Count" method (Tsukamura, M.: Japan J. Tuberc. 12: 46-54, 1964), in which the inhibitory concentration was measured as a concentration that can inhibit the growth of 'countable' colony-forming units. The ratio of strains which were inhibited by such low concentrations as 0.2 microgram/ml isoniazid or 5 micrograms/ml ethionamide was 14%. The result suggests that there are some strains in which isoniazid or ethionamide are clinically effective, though their prevalence was low (14%).
Ethionamide↗
[In-vitro combined effect of antituberculosis drugs on Mycobacterium avium complex].
In-vitro combined activity of antituberculosis drugs on Mycobacterium avium complex strain 13034 (serotype 18) was observed. A twofold dilution series of each drug was combined with 17 additional drugs and the control without drug. Each medium was inoculated by a 0.02 ml-sample of four different bacterial suspensions, original suspension (10 mg wet weight per ml) and its 10(-5), 10(-6) and 10(-7) suspensions, and incubated at 37 degrees C for 28 days. The inoculation was made by a spiral loop that can deliver a 0.02 ml-sample by one inoculation. Since a total of media reached 6480 (1620 combinations x 4 different suspensions), only one strain was investigated in this study. Inoculation size used for determining minimal inhibitory concentrations was adjusted to 20 to 80 colony-forming units per medium. This was obtained by inoculating 10(-6) suspensions. The diameter of colonies was measured on media that were inoculated with 10(-7) suspensions. Since 96% confidence limits of determining minimal inhibitory concentrations are between 1/4 to fourfold, decrease or increase of the minimal inhibitory concentration equal to or above this level was regarded as significant. Such significant change of the minimal inhibitory concentrations occurred in combinations of drugs is shown in Table 2. As shown in tables, no antagonism was observed. The combinations, in which significant decrease was seen, contained ethambutol, sulfadimethoxine and ethionamide. It was shown that these concentrations of the drugs cause marked delay of growth. In control medium, the diameter of colonies was 5-6 mm, whereas in media containing one of these drugs, it was 1 mm.(ABSTRACT TRUNCATED AT 250 WORDS)
Antitubercular Agents↗
[Strongyloidiasis following long-term corticosteroid therapy].
A 64-year-old man who was born and raised in Fukuoka Prefecture was admitted because of dyspnea. The chest X-ray film showed multiple pulmonary cysts. Corticosteroid therapy was given because of repeated episodes of dyspnea and wheezing. He complained of epigastric pain 20 months after administration of corticosteroid therapy. Gastro-endoscopic examination showed inflammatory changes of the gastric mucosa and the biopsy specimens revealed the filariform larvae of Strongyloides stercoralis. Furthermore, the larvae were frequently detected in both sputum specimens and stools. Pyrvinium pamoate was initially administered and was switched to thiabendazole because of the presence of hyperinfection. Although two cycles of thiabendazole treatment were given, the larvae were not eradicated. This case report suggests that long term corticosteroid therapy caused the hyperinfection syndrome of Strongyloides stercoralis in a patient who was auto-infected with this nematode.
Adrenal Cortex Hormones↗
[Differentiation between Mycobacterium malmoense and Mycobacterium nonchromogenicum by ethambutol susceptibility].
Mycobacterium malmoense strains are resistant to 1 microgram/ml ethambutol in Ogawa egg medium, whereas Mycobacterium nonchromogenicum strains are susceptible to this concentration. Therefore, these two Group III nonphotochromogens are differentiated clearly from each other by the susceptibility test for ethambutol 1 microgram/ml. Ninety-five % of Mycobacterium avium complex strains are resistant to this concentration, while M. nonchromogenicum strains are susceptible. Therefore, the test serves for differentiating M. nonchromogenicum from M. avium complex. Previously, Tsukamura (Kekkaku 45: 237, 1970) reported that pathogenic and nonpathogenic mycobacteria of Group II and Group III are differentiated by the susceptibility test to ethambutol, 5 micrograms/ml. However, the use of Ogawa egg medium containing 1 microgram/ml ethambutol is superior to that of 5 micrograms/ml ethambutol for differentiating pathogenic and nonpathogenic ones of the Group III.
Ethambutol↗
[Clinical characteristics of tuberculosis in the aged].
We prospectively studied the clinical characteristics of tuberculosis in the aged from July 1988 to March 1989. Twenty-five of 101 tubercle-bacilli positive patients were 70 years old or more. In these aged patients, decrease of body weight and of serum albumin was predominant. These findings suggest that undernutrition is remarkable in aged patients with tuberculosis, and it may influence their cellular immunity. In fact, the tuberculin reaction was significantly attenuated in the aged patients compared with patients less than 70 years old. Twelve percent of the aged patients showed a negative tuberculin reaction. In clinical diagnosis, it should be kept in mind that tuberculin reaction is sometimes negative in active tuberculosis patients particularly in the aged. The time required for negative conversion of tubercle bacilli was not retarded in the aged patients due to the use of potent chemotherapy regimens containing isoniazid and rifampicin.
Age Factors↗
[Evaluation of T-2588 in the treatment of respiratory tract infection].
T-2588 was used on 55 patients with respiratory tract infections and 44 cases were evaluated; 23 patients with pneumonia, 12 patients with acute bronchitis, 2 patients with chronic bronchitis, 1 patient with diffuse panbronchiolitis and 6 patients with bronchiectasis with infection. Clinical effects of T-2588 were as follows; excellent in 6 and good in 28 patients. The efficacy rate was 77.3% (34/44). Bacteriological effects of T-2588 were prominent in 8 patients infected with B. catarrhalis, H. influenzae, K. pneumoniae and E. coli, but not in a patient infected with P. putida. The elimination rate was 90.0% (9/10 strains). As side effects, stomatitis, anorexia, diarrhea X vomiting and pruritus were observed in one patient each. Abnormal laboratory findings were observed in 4 patients with elevated GOT and/or GPT. These side effects and abnormal laboratory findings were not serious. The usefulness of T-2588 was 68.2% (30/44). Therefore, T-2588 is a useful drug and its effects are promising in clinical management of respiratory tract infections.
Administration, Oral↗