AIDSWEEKLY Plus; Monday, June 29, 2009
Staff Medical Writers

(NewsRx.com) -- According to recent research published in the Chinese Medical Journal, " Virus with nucleoside reverse transcriptase inhibitors (NRTIs) or nonnucleoside reverse transcriptase inhibitors (NNRTIs) resistant mutations show different evolution tendencies when the anti-viral therapies are interrupted. Understanding the replication fitness of drug-resistant virus is important for the study of the prevalence of drug-resistance."

"For this purpose, we characterized the replication capacity of HIV-1 virus carrying lamivudine (3TC) or nevirapine (NVP) resistant mutations. Methods 3TC and NVP resistant variants were induced in vitro by selecting wild type virus in the presence of drugs. For the competitive replication assay, drug-resistant variants were cocultured with wild-type virus in the presence or absence of drugs. The ratios of the viral species were determined over time by using a real-time RT-PCR-based assay. Results 3TC-resistant (M184I mutation) and NVP-resistant (Y181I mutation) virus should be selected in vitro in two different ways. The competitive replication assay showed that the ratio of virus carrying a M184I mutation increased from 98.8%, while the wild type virus decreased to 1.2% after 4 passages in the presence of 3TC; the percentage of virus carrying the Y181I mutation increased to 90.5%, while wild type virus decreased to 9.5% in the presence of NVP. In the absence of drugs, the ratio of virus carrying the M184I mutation decreased to 5.3%, while wild type virus increased to 94.7%; the ratio of virus carrying Y181I increased to 75%, while wild type virus decreased to 25% after 4 passages," wrote J. Li and colleagues (see also HIV/AIDS).

The researchers concluded: " The NVP-resistant virus is fitter than wild type virus even in the absence of NVP that may be the reason Chin Med J (Engl). 2009 May 5;122(9):1081-6."

Li and colleagues published their study in Chinese Medical Journal (Competitive capacity of HIV-1 strains carrying M184I or Y181I drug-resistant mutations. Chin Med J (Engl). 2009 May 5;122(9):1081-6).

For additional information, contact J.Y. Li, Beijing Institute Microbiology & Epidemiology, State Key Laboratory Pathogen & Biosecur, Dept. of AIDS Research, Beijing 100071, People's Republic of China.

The publisher's contact information for the Chinese Medical Journal is: Chinese Medical Association, 42 Dongsi Xidajie, Beijing 100710, People's Republic of China.

Keywords: People's Republic of China, Beijing, HIV/AIDS, AIDS, Acquired Immune Deficiency Syndrome, Acquired Immunodeficiency Syndrome, Drug Development, Drug Resistance, Drugs, Enzyme Research, Enzymes, Enzymology, HIV, Human Immunodeficiency Virus, Immunology, Lamivudine, Nevirapine, Nonnucleoside Reverse Transcriptase Inhibitor, Nucleoside Reverse Transcriptase Inhibitor, Pharmaceuticals, Proteins, Proteomics, Sexually Transmitted Disease, Therapy, Treatment, Viral, Virology.

This article was prepared by AIDS Weekly editors from staff and other reports.

2009-06-29
AW090614

Copyright © 2009 - Charles Henderson, Publisher. All rights Reserved. Permission to reproduce granted to AEGIS by Charles W. Henderson. Authorization to reproduce for personal use granted granted by C. W. Henderson, Publisher, provided that the fee of US$4.50 per copy, per page is paid directly to the Copyright Clearance Center, 27 Congress Street, Salem, Massachusetts 01970, USA. Published by Charles Henderson, Publisher. Editorial & Publishing Office: P.O. Box 5528, Atlanta, GA 30307-0528 / Telephone: (800) 633-4931; Subscription Office: P.O. Box 830409, Birmingham, AL 35283-0409 / FAX: (205) 995-1588 http://www.newsrx.net

AEGiS is made possible through unrestricted grants from the National Library of Medicine, and donations from users like you. Always watch for outdated information. This article first appeared in 2009. This material is designed to support, not replace, the relationship that exists between you and your doctor.