Drug resistance pattern of mycobacterial isolates in HIV and non-HIV population in South India

Background: Emergence of drug resistance has complicated the treatment of tuberculosis (TB). WHO reports India to be one among 27 "high burden" multidrug-resistant (MDR) TB countries. Objective: To diagnose TB and detect drug resistance of mycobacterial isolates in acid-fast bacilli (AFB) smear negative HIV reactive patients (Group A) and compare them with HIV seropositive AFB smear positive (Group B) and HIV-seronegative AFB positive cases (Group C). Materials and Methods: Clinical specimens collected in all groups were processed as per the standard protocol except blood, which was processed by lysis centrifugation technique. They were then inoculated with Lowenstein-Jensen media and the isolates obtained were subjected to drug susceptibility test (DST) by proportion method and genotype MTBDR plus assay. Results: In Group A, 162 patients were included. Of the 443 clinical samples collected, 76 mycobacterial strains were obtained from 67 (41%) patients. Of these, 50 (65.8%) were sensitive to all drugs and 26 (34.2%) resistant to one or more anti-tubercular drugs. Antibiogram of Group A when compared with Group B and C showed that the MDR rate 6.6%, 6.7% and 8% respectively) did not differ much; but resistance to at least single drug was (26 [34.2%], 3 [10%], and 8 [16%]), respectively. Conclusion: Our study suggests that HIV has no influence on the anti-tubercular resistance pattern, but increased MDR rate along with HIV in high TB burden setting stresses the need for early diagnosis and DST in providing proper regimens and improve prognosis.