Abstract:
Aim: This study was aimed at identification of fungal and bacterial contaminants in Tuberculosis
cultures at the Uganda National Reference Laboratory (NTRL).
Methods: The cultures were previously grown on Lowenstein-Jensen (LJ) medium in bottle slants.
The method used involved conventional culture methods and biochemical characterization of the
contaminants. Bacterial cultures were carried out in both aerobic and carbon dioxide incubators
where required and to the respective temperatures of the organisms. Growth was observed between
24-48 hours for bacterial and up to 72 hours for yeast contaminants. Cultures on SDA were also
monitored for three weeks for possible growth of filamentous fungi.
Results: The identified bacteria mostly included; S. pyogenes, S. aureus, E. coli, P. aeruginosa, K.
pneumoniae, and least isolated were; S. marcescens, H. influenza, S. pneumoniae and B. subtilis. Fungal contaminants were A. fumigatus and C. albicans.
Conclusion: Based on this study a relatively increased level of contamination was noted. We
recommend that high level of aseptic techniques be maintained in addition to the current standards
in order to reduce the level of bacterial and fungal contaminants in TB cultures so as to improve the
detection rate of Mycobacteria tuberculosis by culture method.
