Abstract

Dr. Bernaitis L.*, Vipin Unni P. and Rajendran S.

ABSTRACT

Tuberculosis (TB) is the most common cause of death due to a single infectious agent worldwide in adults. India alone accounts for 30% of the global tuberculosis burden. There is a need for a method of cultivation of mycobacteria that is reliable and economical and has a short turnaround time. The present study was attempted to assess the feasibility of using modified Lowenstein-Jensen (LJ) media, the isolation media for mycobacteria. They were compared with the conventional LJ medium, which was the gold standard. Sputum specimens from a total of 1812 clinically suspected cases of TB were studied. All the samples were decontaminated by using the modified Petroff’s method. Each sample was subjected to ZN staining and it was simultaneously inoculated onto the modified LJ medium and the conventional LJ medium. The growth from the cultures were confirmed by ZN staining and biochemical reactions. In DE-LJ the Mycobacterial growth was seen on the second week for +++ samples and on the third week for the ++ and + samples. . Mean number of weeks taken on three experimental slants was compared with mean number of weeks on control slants using using paired‘t’ test. The difference in mean number of weeks taken on supplemented medium was significantly less than that on unsupplemented medium. Modified Lowenstein-Jensen (LJ) media is a better medium as compared to the conventional LJ medium, both in terms of the number of isolates and the isolation rate. It was proved to be a very speedy method and it could isolate Mycobacterium tuberculosis 5- 10 days earlier as compared to the conventional L J medium.