Abstract

SETTING:

National Tuberculosis Reference Laboratory, Addis Ababa, Ethiopia.

OBJECTIVES:

To determine the drug susceptibility pattern of Mycobacterium tuberculosis isolates and to genetically characterise multidrug-resistant tuberculosis (MDR-TB) isolates.

DESIGN:

A total of 107 M. tuberculosis isolates recovered during the period December 2005-August 2006 were tested for drug susceptibility against streptomycin, isoniazid, rifampicin and ethambutol (SHRE) using the proportion method on Löwenstein-Jensen medium. The MDR-TB isolates were tested against kanamycin, ciprofloxacin, capreomycin, D-cycloserine and ethionamide. Genotyping was performed using spoligotyping.

RESULTS:

MDR-TB was observed in one of the 44 new cases (2.3%) and 45/63 previously treated patients (71.4%). Drug susceptibility testing against second-line drugs (SLDs) showed that 26.1% of all MDR-TB isolates were susceptible to all SLDs tested and 73.9% were resistant to one or more classes of SLD. Extensively drug-resistant (XDR) TB was detected in two isolates (4.4%). T3_ETH was the predominant spoligotype, followed by CAS_KILI. In this African setting, no Beijing spoligotype was identified.

CONCLUSION:

Both MDR- and XDR-TB are present in Ethiopian patients. MDR-TB was found to be associated with T3 and Central Asian genotypes.