Improved recovery of Mycobacterium tuberculosis from pleural aspirates: Bedside inoculation, heparinized containers and liquid culture media

The effects of bedside inoculation, heparinized containers and liquid cultu re media on the recovery of Mycobacterium tuberculosis from pleural aspirat es were evaluated in this study. Of 155 patients, 63 were diagnosed to have pleural effusion tuberculous in origin. The overall recovery of M. tubercu losis was 57.1%. Bedside inoculation of the specimens produced a significan tly higher yield than laboratory inoculation using non-heparinized specimen s. When the pleural aspirates were transported in heparinized containers, t he recovery rate was comparable to that from bedside inoculation, but lower when non-heparinized containers were used. No significant difference was f ound in recovery rate between the tao liquid media, but the rate was signif icantly higher with the use of liquid media than conventional solid media. Thus, bedside inoculation of pleural aspirates, use of heparinized containe rs for transport for delayed inoculation in the laboratory and use of liqui d culture media are recommended.