Molecular Characterization of Mycobacterium Tuberculosis in HIV Patients Receiving Antiretroviral Drugs in Cameroon.

BACKGROUND

Tuberculosis (TB) remains a leading cause of mortality among people living with HIV/AIDS, who face a tenfold higher risk of Mycobacterium tuberculosis (MTB) infection. TB-HIV coinfection complicates disease management due to drug interactions, overlapping toxicities, immune reconstitution inflammatory syndrome, and high treatment burdens, potentially driving drug resistance. The emergence of resistant MTB further exacerbates this challenge. This study evaluated the drug resistance profile of MTB in TB-confirmed samples from HIV-positive patients.

METHODS

An analytical cross-sectional study was conducted on 216 sputum samples from HIV patients on antiretroviral therapy at Jamot Hospital, Yaoundé, Cameroon (June-September 2022). Two consecutive samples per patient underwent fluorescent microscopy (Auramine-Rhodamine stain) and TB-Loop-Mediated Isothermal Amplification. DNA was extracted using the GenoLyse® kit (Hain Lifescience, Germany), and drug resistance profiles were assessed via GenoType® MTBDRplus and MTBDRsl line probe assays.

RESULTS

TB was confirmed in 12.04% (26/216) of participants. Rifampicin (RIF) and isoniazid (INH) resistance were each detected in 50% (13/26) of cases, with 23% (6/26) exhibiting multidrug-resistance (MDR). Predominant mutations included rpoB MUT2B (15.38%) for RIF and inhA MUT2A (23.06%) for INH. Second-line resistance analysis revealed 61.54% (8/13) resistance to kanamycin (KAN)/amikacin (AMK)/viomycin, 7.69% (1/13) to AMK/capreomycin/viomycin, and 7.69% (1/13) to KAN. Notably, 61.54% (8/13) lacked the rrs wild-type probe, indicating resistance to injectable TB drugs.

CONCLUSION

High MDR-TB prevalence was observed among HIV-TB coinfected patients, underscoring the urgent need for enhanced resistance surveillance and optimized treatment strategies in TB/HIV-endemic regions like Cameroon. Further research is warranted to elucidate HIV's role in driving TB drug resistance.