A study was conducted to evaluate the usefulness of pyruvate medium for isolation of M.bovis from human material and additional yield of M. tuberculosis resistant to INH. Specimens from both rural and urban populations were included for this study in order to understand the problem in both the situations. There were two studies in progress at the National Tuberculosis Institute when pyruvate media slopes were introduced for culture purpose. One study was an epidemiological survey; 2518 sputum specimens received from 51 villages covering a population of about 32,300 were used. The specimens were collected from persons aged 5 years and above showing abnormal shadow on X-ray. The other study was conducted in collaboration with the State Tuberculosis Centre, Bangalore; 1204 sputum specimens were received from out patients attending the centre. In addition to LJ medium, pyruvate medium was used for isolation purposes. Identification and sensitivity tests were done on positive cultures as per routine. In all, 129 cultures of tubercle bacilli were isolated from 2118 specimens belonging to study 1 and 398 from 1204 specimens belonging to study 2. The number of cultures contaminated were 253 and 35 respectively. No M.bovis was isolated in either study. There were 24 and 23 cultures resistant to INH among those isolated from LJ and pyruvate medium respectively. Thus, no increase was observed in the isolation of INH resistant strains using pyruvate medium.

Hence, no benefit was derived by using this medium over and above what was obtained from plain Lowenstein Jensen medium in both the situations.