421. Transmitted HIV-1 drug resistance in untreated Romanian patients
Session: Poster Abstract Session: HIV - Antiretroviral Therapy
Friday, October 21, 2011
Room: Poster Hall B1
Background: The transmission of drug-resistant HIV-1 has important implications for the successful management of antiretroviral therapy among infected individuals, restricting drug options and increasing the risk of suboptimal treatment outcomes. Considering the fact that data on non-B subtypes are limited, and subtype F is predominant in Romania, our goal is to analyze resistance mutations in the pol gene of HIV-1 isolates from drug-naive patients.

Methods: Twenty HIV-1 strains from untreated individuals, newly diagnosed (n = 10) and chronically infected (n = 10), with detectable HIV RNA viral load were included in this study. Among newly diagnosed patients, recent infections (acquired in the previous 6 months) were detected by BED-CEIA in 2/10 cases. Resistance genotyping was performed using the ViroSeq HIV-1 Genotyping System (Celera Diagnostics, Alameda, USA). For subtyping purposes and drug resistance interpretation all sequences were submitted to the Stanford University HIVdatabase.

Results: Although F subtype remained prevalent, we observed an increase of HIV-1 infections which involved other subtypes, especially in newly diagnosed patients: 13/20 strains belonged to the F subtype, 2/20 to the B subtype, 2/20 to the C subtype and 3 were D/F (2/20) and CRF02_AG/G. All the studied HIV-1 isolates carried many minor mutations in the protease gene often detected at polymorphic positions. L89M and R41K were the most common accessory protease inhibitor resistance mutations (17/20 patients), followed by I15V (16/20 patients), M36I (16/20 patients) and L63T (15/20 patients). The analysis of the RT gene revealed many accessory mutations and some atypical substitutions at key positions known to be linked with drug resistance: M41W (1/20 patients), T69S (1/20 patients), V106IV (1/20 patients), E138G (1/20 patients).

Conclusion: No major resistance mutations were detected in HIV-1 strains isolated from untreated Romanian patients, but all the studied HIV-1 isolates carried minor mutations with high frequencies in the protease and RT gene. Minor mutations may not result in a significant decrease in susceptibility, but may be associated with an increase in the resistance levels associated with major mutations and thus long-term failure of therapy.

Subject Category: H. HIV/AIDS and other retroviruses

Aura Temereanca1, Luminita Ene2, Camelia Sultana1, Loredana Manolescu1, Dan Duiculescu, MD, PhD3 and Simona Ruta1, (1)“Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania, (2)”Dr. Victor Babes” Hospital for Infectious and Tropical Diseases , Bucharest, Romania, (3)”Dr. Victor Babes” Hospital for Infectious and Tropical Diseases, Bucharest, Romania


A. Temereanca, None

L. Ene, None

C. Sultana, None

L. Manolescu, None

D. Duiculescu, None

S. Ruta, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.