WHO Co-operative studies on a simple culture technique for the isolation of mycobacteria

摘要

Tuberculosis surveys are in progress in many countries that do not have adequate laboratory facilities for carrying out complicated bacteriological procedures. As part of a WHO co-operative research programme, studies have been undertaken with a view to developing a simple culture technique for the isolation of mycobacteria that does not require elaborate equipment. This paper is the first report on these co-operative studies.Storage and transport are known to affect adversely the viability of Mycobacterium tuberculosis in pathological specimens, thus giving rise to poor culture results and indicating the advisability of culturing such specimens on the spot. The preparation of the efficient and widely used Löwenstein-Jensen (L-J) culture medium, however, requires materials and facilities that are not easy available in developing countries. In an attempt to overcome this difficulty, the Tuberculosis Research Institute in Prague has developed a semi-synthetic liquid medium that can be prepared in bulk, concentrated and lyophilized, and sent even to distant laboratories.The present paper describes in detail the preparation of this lyophilized medium, which can be stored at room temperature for at least 6-12 months and is easy to reconstitute, and discusses the growth characteristics of mycobacteria multiplied in it.Experience in Czechoslovakia, where between 1953 and 1962 nearly 21 million cultures have been made with the medium, has shown that it is quite satisfactory and even slightly superior to L-J medium in certain respects.