Development of liguid media for isolation of Mycobacterium tuberculosis from pleural effusion, ascitic fluid and cerebrospinal fluid

Abstract

The use of liquid media for isolation of M. tuberculosis from pleural effusion, ascetic fluid and CSF was found to be more efficient than conventional methods. Middlebrook 7H9 medium was selected to be the standard liquid media in the effort to develop a new liquid media in this study. The developed liquid media should be contained 5% albumin. Bovine albumin was more efficient than human albumin. The addition of antibiotics was not harmful to the growth of this organism and also useful for the decontamination of specimens. The efficacy of the developed liquid media was not significantly difference from the standard liquid media (P>0.05) in culturing M. tuberculosis H37Rv. However, the cost of the developed liquid media was one fifth of that of the standard liquid media. The use of both liquid media for isolation of M. tuberculosis from the specimens were compared with Lowenstein-Jensen (L-J) media. There were twenty-four positive for M. tuberculosis out of the ninety-four specimens. This organism was isolated from fifteen pleural effusions, one ascetic fluid and eight CSF. By using standard liquid media, developed liquid media and L-J media, positive results were obtained in 8, 5 and 4 specimens respectively. In this study, it was confirmed that the use of liquid media was the efficient method for isolation of tubercle bacilli from liquid specimens which contained few organisms and this method was more useful than conventional media. Eventhough, the efficacy of the developed liquid medium was less than that of the standard liquid medium but the results obtained from this study would provide useful informations for further study in this aspect.