The nature of cross-resistance is discussed in the present paper. In conclusion, the crossresistance is a phenomenon in which multi-resistant mutants produced by a mutation are obtained by selection with different drugs. Hence, the cross-resistance, in its nature, should be ‘complete cross-resistance’. The phenomenon of ‘one-way cross-resistance’ (organisms resistant to two drugs, A and B, are selected by drug A, but those are not selected by drug B) is due to the fact that different populations are selected by drugs A and B.
The most marked examples of the cross-resistance in tubercle bacilli are cross-resistance relationships concerning with aminoglycoside antibiotics. In respect to these antibiotics, the following mutants are observed; (1) Mutants resistant to only kanamycin (low level of resistance); (2) mutants triply resistant to viomycin, emviomycin and capreomycin (low levels of resistance); (3) mutants triply resistant to kanamycin, lividomycin and paromomycin (low level of resistance to kanamycin and high levels of resistance to the latter two); (4) mutants quadruply resistant to capreomycin, kanamycin, lividomycin and paromomycin (low level of resistance to capreomycin and high levels of resistance to the latter three); (5) mutants hextuply resistant to viomycin, emviomycin, capreomycin, kanamycin, lividomycin and paromomycin (high levels of resistance to six drugs). The phenomenon that these triply, quadruply and hextuply resistant mutants are selected by each drug is resulted in cross-resistance.
‘One -way cross-resistance’ is known between kanamycin and capreomycin. Mutants resistant to a high concentration of kanamycin, which is selected by kanamycin, are resistant to a low concentration of capreomycin. On the other hand, mutants resistant to a low concentration of capreomycin, which is selected by capreomycin, are susceptible to kanamycin. This phenomenon is based on the fact that quadruply resistant mutants are selected by kanamycin and triply resistant mutants are selected by capreomycin. This occurs from the fact that the prevalence rate of triply resistant mutants (resistant to viomycin, emviomycin and capreomycin) in the parent H₃₇Rv strain is 10^-6 and that of quadruply resistant mutants is 10^-7 to 10^-8, and the former is more easily selected by capreomycin (the former has a higher chance to be selected by capreomycin). In fact, the present author studied 27 strains derived from single colonies which grew on media containing 200μg/ml capreomycin. Out of these, 26 were triply resistant mutants and only one belonged to quadruply resistant ones. Hence, if one takes colonies which have grown on media containing capreomycin, the majority of the colonies belong to triply resistant mutants and these are not resistant to kanamycin. This is observed as ‘one-way cross-resistance’.
‘One-way cross-resistance’ between PAS and 4-acetylamino-benzaldehyde-thiosemicarbazone (Tb₁) and between ethionamide and Tbi could also be explained similarly.

抄録全体を表示

In order to investigate the relationship among the chemical structure of tetrazolium salts their inhibitory activity against growth of mycobacteria and their reduction by mycobacteria, various tetrazolium salts containing heterocyclic compound at the 5-position of tetrazolium salt, were synthesized as pure hydrochloric acid salt. Most of them contained some moles of crystal water. Molecular formulas of them are as follows.
5-(2-thienyl)-2, 3-diphenyl-2H-tetrazolium chloride (STC) C₁₇H₁₃N₄SCl·H₂O
5-(3-thienyl)-2, 3-diphenyl-2H-tetrazolium chloride (β-STC) C₁₇H₁₃N₄SCl·H₂O
5-(2-furoyl)-2, 3-diphenyl-2H-tetrazolium chloride (OTC) C₁₇H₁₃N₄OCl
5-(3-furoyl)-2, 3-diphenyl-2H-tetrazolium chloride (β-OTC) C₁₇H₁₃N₄OCl·H₂O
5-(2-pyridyl)-2, 3-diphenyl-2H-tetrazolium chloride (α-PTC) C₁₈H₁₄N₅Cl·4H₂O
5-(3-pyridyl)-2, 3-diphenyl-2H-tetrazolium chloride (β-PTC) C₁₈H₁₄N₅Cl·7H₂O
5-(4-pyridyl)-2, 3-diphenyl-2H-tetrazolium chloride (β-PTC) C₁₈H₁₄N₅Cl·6.5H₂O
5-methyl-2, 3-diphenyl-2H-tetrazolium chloride (MDT) C₁₄H₁₃N₄Cl·H₂O
2, 3, 5-triphenyl-2H-tetrazolium chloride (TTC) C₁₉H₁₅N₄Cl·2H₂O
These compounds were examined on their inhibitory activity against growth of various kinds of mycobacteria on both Ogawa's solid egg medium and Kirchner's fluid medium, as well as on their capability of developing color as a result of their reduction by mycobacteria.
Only one of them, α-PTC, did not develop color on its reduction by various kinds of mycobacteria even in their logarithmic phase of growth, whereas this compound as well as the other compounds did on their reduction by various kinds of intestinal bacilli. α-PTC, as well as β-PTC, also showed a slight mycobacterio static effect for tubercle bacilli. In the reduction by mycobacteria, this particular nature of α-PTC seems to be related to its affinity with reducing enzymes in cell membrane of mycobacteria, because the reduction potential of α-PTC is not much different from that of the other compounds. From these results, it is concluded that in these compounds, their reduction by mycobacteria might be unrelated to their growth inhibitory effect against mycobacteria.
On the basis of these findings, and considering molecular optical absorption coefficient and maximum absorption of these compounds, STC and OTC were regarded as the best two for a rapid detection of growth of mycobacteria.

抄録全体を表示

Six tenths per cent of Sodium hydroxide was used to estimate the time required for the ad sorption-invasion of mycobacteriophage B-1 strain to 7 strains of mycobacteria which had different generation time and different latent period in infection with the same phage. Mycobacteria used were M. smegmatis, atypical mycobacterium P-17, P-18, P-22, P-40, P-44 and Mycobacterium tuberculosis var. hominis H₃₇Ra.
The results obtained are summarized as follows.
1) B-1 Phage was adsorbed on and invaded into the host cells within 30 sec after mixing the phages and the host cells.
2) Adsorption-invasion time was the same in all the mycobacterial phage and host systems used.
3) The number of plaque-formant increased logarithmically and showed the maximal value in 5 to 10 min after mixing the phages and the host cells.

抄録全体を表示

Recently, the authors have encountered a case of pulmonary disease due to Mycobacteriumaviuin-intracellulare complex.
A 48-year-old man complained of slight fever elevation. Chest X-ray films demonstrated infiltrative shadows and slow-growing mycobacteria of the same colonial morphology were repeatedly isolated from his sputa, gastric juice as well as bronchial secretion.
The strain isolated was identified by a detailed biological, biochemical and serological study. However, it was difficult to differentiate as to whether it belonged to M. aviuin or M. intracellulare.

抄録全体を表示

The Research Committee for Tuberculosis, Ryoken, conducted the cooperative study on the background factors of tuberculosis patients staying long periods in 73 hospitals and sanatoria belonged to the committee in 1975. First the duration of admission of pulmonary tuberculosis patients who were admitted in 73 institutions on October 15, 1975 was surveyed. Thereafter the background factors of patients staying for more than 5 years in each institution were studied.
The results presented in part 1. were summarized as follows:
1) The duration of stay of 14, 503 patiens were reported from each institution. The number of cases staying less than 6 months was 5, 975 (41.2%), less than 1 year was 8, 463 (58.4%) and the number of cases staying for more than 5 years was 1, 939 (13.4%). The duration of stay was longer in national, prefectural or municipal sanatoria and was shorter in university hospitals, national, prefectual or municipal hospitals and some private hospitals.
2) The further studies and analysis were made on 1, 936 patients who stayed for more than 5 years in each institution. The patients stayed for less than 8 years were 664, 8 to 10 years were 316, 10 to 15 years were 551, 15 to 20 years were 243 and for more than 20 years were 162 in number. Therefore the patients stayed for less than 10 years and for more than 10 years were nearly the same in number.
3) Among 1, 936 patients, 664 (34.3%) stayed in each institution by failing sputum negative conversion of tubercle bacilli. The remaining 1, 272 patients were negative for tubercle bacilli.
4) The duration of stay was not so markedly different between sputum positive and sputum negative cases.
5) The proportion of patients showing negative sputum as lowest in university hospitals and highest in national sanatoria.
6) The age distribution of patients was similar between sputum negative and positive cases.
7) The rate of sputum positive cases was much higher in far advanced cases and in cases discharging a large amount of tubercle bacilli on admission.
8) The rate of sputum positive cases was much higher in the retreatment group than in theoriginal treatment group.
9) The respiratory complication was seen in 437 cases (22.6%) on admission and in 828 cases (42.8%) at the time of the survey.
10) The non-respiratory complications other than tuberculosis was seen in 432 cases (22.3%) on admission and in 802 cases (41.4%) at the time of the survey.
11) The extra-pulmonary tuberculosis was seen in 96 cases (5.0%) on admission and in 69 cases (3.6%) at the survey time.
12) Rifampicin was used in 46.1% of sputum negative group and in 92.2% of sputum positive group during their stay in each istitution.
13) The isolation of atypical mycobacteria from sputum was seen in 63 cases (3.3%) and cases diagnosed as pulmonary atypical mycobacteriosis were 7 cases (0.4%). The number of combined cases with tuberculosis and atypical mycobacteriosis were 14 (0.7%). The suspected atypical mycobacteriosis was seen in 38 cases (2.0%).

抄録全体を表示