Microscopic observation of broth cultures: a rapid and efficient method for detection and drug susceptibility testing of mycobacterium in sputum of children

ABSTRACT

We tried to develop a new, efficient, rapid, reliable and inexpensive method that permits mycobacteria detection and drug susceptibility for children and adolescents with pulmonary tuberculosis. Sputum samples were cultured by using [1]. the microscopic observation broth-drug susceptibility [MODS] method; [2]. radiometric culture technique by using BACTEC system; and [3]. culture on Lowenstein Jensen medium [LJ], in addition to Ziehl-Neelsen staining of sputum. Patients underwent tuberculin skin test. The results proved that the sensitivity of the different diagnostic tests was MODS 79.3%, BACTEC 96.5%, and culture on LJ medium 55%. Specificity was high for BACTEC, MODS, and LJ medium as none of the 18 control sputum samples were positive by any method. The mean time of detection of mycobacteria was MODS 10.4 +/- 3.79 days, BACTEC 9.1 +/- 3.1 days, and LJ medium 38.5 +/- 10.3 days. The mean time for doing susceptibility testing was MODS 10.7 +/- 3.86 days, BACTEC 9.6 +/- 3.1 days, and LJ medium 38.9 +/- 10.6 days. Cost per sample for detection and susceptibility respectively was MODS 2.7 and 17.5 L.E., BACTEC 25 and 77.5 L.E. and LJ 1.7 and 12.5 L.E. For diagnosis of tuberculosis, MODS method is a rapid, cheap, easy and efficient method for detection and performing susceptibility tests in Egypt