Detection of drug resistant Mycobacterium tuberculosis among patients with and without HIV infection in a rural setting

Abstract

Objective: To analyse the sensitivity of Mycobacterium tuberculosis by nitrate reductase assay (NRA) and the Hain molecular line probe assay (LPA) in sputa of tuberculosis (TB)/HIV co-infected patients in Guyana. Design: Sputum samples were collected from known TB patients at Georgetown Chest Clinic and were analysed at the Reference Laboratory, Guyana, over the period April 2010 to April 2011. Results: Both methods recorded greater sensitivity for rifampin (RIF) than of isoniazid (INH). Both methods detected four RIF resistant, two INH resistant and two multi-drug resistant (MDR) strains and they had greater negative agreement indices than positive agreement indices. Conclusion: It was established that the sensitivity of Mycobacterium tuberculosis by the NRA and Hain LPA in TB/HIV co-infected patients has acceptable correlation and that HIV infection does not affect drug susceptibility testing.