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INVESTIGATIONS INTO THE ISOLATION OF “M. TUBERCULOSIS” FROM URINE
Author(s) -
HILL CHARLES A. ST,
GOW JAMES G.
Publication year - 1966
Publication title -
british journal of urology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.773
H-Index - 148
eISSN - 1464-410X
pISSN - 0007-1331
DOI - 10.1111/j.1464-410x.1966.tb09695.x
Subject(s) - urine , tuberculosis , isolation (microbiology) , filtration (mathematics) , urinary system , inoculation , medicine , liquid culture , chromatography , surgery , chemistry , biology , microbiology and biotechnology , immunology , pathology , mathematics , statistics , botany
SUMMARY AND CONCLUSIONS Observations on the effects of various factors influencing the efficiency of isolation of M. tuberculosis from tuberculous urine have been made on a series of 8, 761 such specimens submitted for laboratory examination over a period of twelve years. These observations have led to the following conclusions:—‐ 1. Guinea–pig inoculation gives a higher number of positive results than artificial culture. 2. Both guinea–pig inoculation and artificial culture must be used otherwise a significant number of urines containing M. tuberculosis will give a negative result. 3. Even if both methods are used, only about one–third of urine specimens from patients with active genito–urinary tuberculosis will give positive isolations of M. tuberculosis. 4. Laboratory diagnosis can be improved by examining three consecutive early–morning specimens, but even so, only about half of the cases of active genito–urinary tuberculosis will reveal a positive urine. 5. Membrane filtration and artificial culture give slightly better results than the culture of centrifuged deposits. The addition of membrane filtration as a third method of isolation of M. tuberculosis is technically not easy, but produces a small number of positive results in specimens negative by the other two methods. 6. Increasing the number of culture media slopes improves the results of artificial cultural methods. 7. Variations in centrifuge speeds and the use of American Trudeau Society media instead of Lowenstein–Jensen media did not significantly influence the results. Commercially prepared Lowenstein–Jensen media gave results as good as the medium prepared in the laboratory. 8. A smaller proportion of positive M. tuberculosis isolations were obtained from specimens treated for forty minutes with two per cent, sodium hydroxide than from specimens treated for twenty minutes. The difference, however, is not statistically significant. 9. A normal urinary deposit does not exclude the possibility of isolating M. tuberculosis from the specimen although the chances are greater in specimens of urine which contain excess pus cells.