Characterization of clinical isolates of Mycobacterium tuberculosis resistant to drugs and detection of RpoB mutation in multidrug-resistant tuberculosis in the Philippines.

Setting: Retrospective study of Mycobacterium tuberculosis isolates at the STD/AIDS Cooperative Central Laboratory, Philippines.

Objective: To describe patterns of M. tuberculosis resistance against first-line anti-tuberculosis drugs, and to analyze the rpoB gene codon mutation of rifampicin (RMP) resistant isolates and correlate genotypic and phenotypic patterns.

A new improved method for the concentration of HIV-1 infective particles.

Improvement of the sensitivity of detection systems for human immunodeficiency virus-1 (HIV-1) has been carried out. One approach to improve the sensitivity is purification and/or concentration of the virus from a specimen. In this study, a method for concentrating HIV-1 using polyethylene glycol (PEG) has been re-evaluated and the optimal protocol for concentrating the virus from low-titer specimens was determined.