Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Retrovirology cung cấp cho các bạn kiến thức về ngành y đề tài: "Phylodynamics of HIV-1 Circulating Recombinant Forms 12_BF and 38_BF in Argentina and Uruguay. | Bello et al. Retrovirology 2010 7 22 http content 7 1 22 RETROVIROLOGY RESEARCH Open Access Phylodynamics of HIV-1 Circulating Recombinant Forms 12_BF and 38_BF in Argentina and Uruguay Gonzalo Bello 1 Paula C Aulicino2 Dora Ruchansky3 Monick L Guimaraes1 Cecilio Lopez-Galindez4 4 3 2 2 2 1 Concha Casado Hector Chiparelli Carlos Rocco Andrea Mangano Luisa Sen Mariza G Morgado Abstract Background Although HIV-1 CRF12_BF and CRF38_BF are two epidemiologically important recombinant lineages circulating in Argentina and Uruguay little is known about their population dynamics. Methods A total of 120 CRF12_BF-like and 20 CRF38_BF-like pol recombinant sequences collected in Argentina and Uruguay from 1997 to 2009 were subjected to phylogenetic and Bayesian coalescent-based analyses to estimate evolutionary and demographic parameters. Results Phylogenetic analyses revealed that CRF12_BF viruses from Argentina and Uruguay constitute a single epidemic with multiple genetic exchanges among countries whereas circulation of the CRF38_BF seems to be confined to Uruguay. The mean estimated substitution rate of CRF12_BF at pol gene X 10-3 substitutions site year was similar to that previously described for subtype B. According to our estimates CRF12_BF and CRF38_BF originated at 1983 1978-1988 and 1986 1981-1990 respectively. After their emergence the CRF12_BF and CRF38_BF epidemics seem to have experienced a period of rapid expansion with initial growth rates of around year-1 and year-1 respectively. Later the rate of spread of these CRFs_BF seems to have slowed down since the mid-1990s. Conclusions Our results suggest that CRF12_BF and CRF38_BF viruses were generated during the 1980s shortly after the estimated introduction of subtype F1 in South America 1975-1980 . After an initial phase of fast exponential expansion the rate of spread of both CRFs_BF epidemics seems to have slowed down thereby following a demographic pattern that resembles .
