Incidence of multidrug resistance in Mycobacterium tuberculosis in a tertiary care hospital in South India--a prospective study.

Multidrug resistant tuberculosis (MDR-TB) is one worrisome element in this era of pandemic antibiotic resistance. This demands a need for diagnosis, and incidence of primary and acquired resistance to help in better management. Smear positive respiratory samples collected over a period of one year were processed for detection of M. tuberculosis, using biochemical methods and susceptibility to p-nitro benzoic acid. Finally, strains detected by the above method were subjected to susceptibility for 2 drugs--Isoniazid and Rifampicin by Absolute concentration method to detect multidrug resistant strains and mono-resistant strains. The study showed primary and acquired resistance for both drugs to be 1.25% and 19% respectively. The data was consistent with the prevalence values available from studies both in India and globally. Finally our study showed MDR-TB to be present more in default patients than new cases.