Various mycobacterial species (22 species, 178 strains) were studied for their reactivity to DNA probe specific for Mycobacterium tuberculosis complex (MTC), M.avium or M.in tracellulare, using Gen-Probe (R) Rapid Diagnostic System (Gen-Probe Inc., San Diego, Calif., U. S. A.).All the MTC strains, including M.tuberculosis, M.africanum, M.bovis and M.microti reacted with MTC-DNA probe at the% hybridization value of 42.8-51.9% (values higher than 10% are regarded as positive), but their reactivity to MAC-DNA probes (0.8-2.5%) was under the cut off value (10%).The test strains (28 strains) of M.avium complex (MAC) segregated into two groups on the basis of reactivity to DNA probes specific for M.avium and M.intracellulare, that is, one group (16 strains) positively reacted with M.avium-probe but not with M.intracellulare-probe, and the other group (12 strains) showed the converse reactivity.The two groups did not show a reactivity with MTC-probe higher than the cut off value.Nontuberculous mycobacteria other than MAC, including M.kansasii, M.marinum, M.simiae, M.asiaticum, M.scrofulaceum, M.gordonae, M.szulgai, M.malmoense, M.xenopi, M.gastri, M.nonchromogenicum, M.terrae, M.triviale, M.fortuitum, and M.chelonae (subsp. abscessus and chelonae) reacted with neither MTC-nor MAC-probe and values for % hybridization (0.6-3.6%) were lower than the cut off value.These findings indicate extremely supreior specificity of the DNA probes Gen-Probe for MTC, M.avium and M.intracellulare, thereby indicating the usefulness of Gen-Probe Rapid Diagnostic System for the MTC and MAC in clinical use.

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A study was made for 13 cases of patients over 80 years of age who received medical treatment for tuberculosis.
Four factors of onset of tuberculosis at old age were indicated.
1.No opportunity for examination of X-ray for old generation.
2.Atypical shadows on the chest X-ray film.
3.Low stress tolerance.
4.Exacerbation of old tuberculosis during the treatment of other diseases.
The results suggest the possibility of increasing pulmonary tuberculosis among the elderly persons in the near future.

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Mycobacterium fortuitum strains F-3 and 126 were studied for their virulence to mice, by being given intravenously to BALB/c strain mice, in terms of incidence of spinning disease, degree of gross renal lesions and growth of organisms in kidneys.In three experi ments separately carried out, strain 126 showed considerably higher virulence than strain F-3. In particular, in experiment 2, much higher incidence of spinning disease was seen in strain 126-infected mice than in strain F-3-infected ones.In experiment 3, the degree of gross renal lesions was significantly higher (P<0.025, X²-test) in the strain 126-infected animals than in the F-3-infected ones.Moreover, in experiment 2, the number of viable units in kidneys was significantly larger in the case of strain 126-nduced infection than in the case of strain F3-induced one (P<0.01, Student's t-test).
Secondly the two M.fortuitum strains were studied for their activity to trigger chemi luminescence (a parameter for respiratory burst) of murine peritoneal macrophages, due to their contact with macrophages.In two of four experiments separately performed, strain 126 exhibited much lower activity of macrophage chemiluminescence-triggering than strain F-3.In the remaining two experiments, the triggering activities of the two strains were at almost the same level, although the activity of strain 126 was still somewhat lower than that of strain F-3.These findings indicate that strain 126 had lowered ability to induce active oxygen radical production in host macrophages in response to cell-to-cell contact (microbes vursus macrophages) than in the case of strain F-3.This may result in an in ferior expression of oxygen-dependent antimicrobial mechanisms in macrophages after phagocytosis of strain 126, compared to the case of macrophages ingested strain F-3. Therefore, at least in the two M.fortuitum strains tested here, there seems to be in part a converse correlation between their virulence to mice and macrophage chemiluminescencetriggering activity.

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A 16-year-old female was admitted to our hospital six months ago.On X-ray exami nation of the test, swelling of lymph nodes in the right mediastinum was seen. CT scan showed multiple lymph node swelling in the neck, mediastinum and abdomen. On open abdominal lymph node biopsy, she was diagnosed as tuberculous lymphadenitis and liver tuberculosis.Antituberculous chemotherapy consisting of INH, RFP, EB and SM was started.
After regular treatment, right mediastinal lymph nodes were markedly reduced in size on chest X-ray film. At present, she is in fine condition.Suprisingly, her condition has improved to a great extent within six months.

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In vitro antituberculous activities of three newly developed quinolones, fleroxacin (FLRX, AM-833), lomefloxacin (LFLX) and sparfloxacin (SPFX, AT-4140) were evaluated comparison to that of ofloxacin (OFLX) using M.tuberculosis strains isolated from patients and the Ogawa egg medium.
SPFX was apparently more active than OFLX, but both FLRX and LFLX were less active.SPFX inhibited completely the growth of all 20 strains of M.tuberculosis isolated from patients who were not previously treated with OFLX in a concentration of 1.25 ug/ml. However, this agent inhibited the growth of only 4 strains (28.6%) of 14 OFLXresistant M.tuberculosis in a concentration of 1.25, u, g/m/, suggesting a partial cross-resistance between SPFX and OFLX.

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For many years tuberculosis has been known to occur with greater frequency among persons with disorders that impair host defenses.In most instances these processes interfere with the immune response to Mycobacterium tuberculosis, whereas, in a few, such as silicosis, the probable abnormality is a nonimmune defect in macrophage function. Infection with the human immunodeficiency virus (HIV) causes progressive and ultimately profound depression of both humoral and cell-mediated immunity and, thus, is an extremely potent risk-factor for tuberculosis.Presumably the major effect of HIV infection that predisposes persons to developing tuberculosis is the reduction in circulating T-helper (CD4⁺) lym phocytes which causes a reduction in cytokine production and a consequent decrease in the functional capabilities of macrophages.However, a number of questions concerning patho genesis of tuberculosis related to HIV remain.
Available data suggest that the magnitude of the risk for developing tuberculosis among persons infected with both HIV and M.tuberculosis is very high, 8% in one prospec tive study.Because of the epidemic of HIV infection, the progressive downward trend in the incidence of tuberculosis in the United States has reversed and in 1989 there was a 5% increase in the number of cases.Preliminary data for 1990 suggest that there will be n 8 to 10% increase over 1989.Also in the United States approximately 3% of tuberculosis patients have been found to be HIV seropositive.
The clinical features of tuberculosis in patients with HIV infection vary depending on the degree of immunosuppression.With mild immunosuppression early in the course of HIV infection tuberculosis presents in a “typical” way with positive tuberculin skin tests, upperlobe cavitary infiltrates on chest film and positive sputum smears and cultures.As the HIV infection progresses, the mode of presentation of tuberculosis becomes more “atypical” with negative skin tests, multiple sites of involvement, chest films showing diffuse noncavitary infiltrates often accompanied by intrathoracic lymphadenopathy.The key to diagnosis is maintaining a high index of suspicion for tuberculosis, especially in patients with advanced HIV disease and including appropriate laboratory examinations in the evaluations of such persons.
Regardless of the stage of HIV infection the response to treatment for tuberculosis is generally favorable if it is begun promptly.Standard therapy utilizing isoniazid, rifampin, and pyrazinamide with or without ethambutol have been associated with high rates of cure. Relapse has been uncommon. There has been, however, at least one outbreak of tuberculosis caused by isoniazid and rifampin resistant organisms in which the response to therapy was very poor.Preventive therapy with isoniazid is probably effective as well but this has not been substantiated. Issues related to infection control are of special concern given the interaction between HIV infection and tuberculosis.Transmission of M.tuberculosis to other HIV-infected patients and to health-care workers has been documented to be associated with the use of aerosol pentamidine prophylaxis for Pneumocystis carinii and with diagnostic sputum induction.

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