Genetic diversity of GBV-C / HGV strains from Argentina: characterization by a novel RFLP, c-DNA sequencing and phylogenetic analysis of 5’ UTR

OUBIÑA JR; MATHET V; FELD M; FERRARIO D; DELLA LATTA MP; VERDUN R; SANCHEZ DO; QUARLERI JF

Bethesda, Maryland

Simposio; 6th International Symposium on Hepatitis C & Related Viruses; 1999

Aim: To determine genetic relatedness of HGV / GBV-C viral isolates from Argentine with previous characterized strains from around the world. Patients, Materials and Methods: Seventy HIV infected-IVDU were studied. Seric RNA was obtained by GTC-phenol-chloroform extraction. RT-Nested PCR was performed using primers for the 5´UTR.  Amplicons of 325 - 329 bp were expected. RFLP was carried out by cleavage with Hinf I, Aat II and Aci I. 325 – 329 bp specific bands were eluted and purified from polyacrilamide gels, and both c-DNA strands directly sequenced. Sequences were aligned with Clustal X program. Evolutionary distances between 171 sequences were determined with DNADIST program of the PHYLIP package (version 3.5c). The computed distances were used for the construction of phylogenetic trees by using the neighbour-joining method. Trees´ robustness was established by bootstrap analysis regarding bootstrap values lesser than 70% as not providing strong support for the phylogenetic grouping. Results: Twenty-one samples were RNA positive. No statistical differences of HGV / GBV-C RNA prevalence were observed among currently infected patients with regard to gender (p=0.082) or age (<30 yr old vs. 30 yr or older: p=0.57). RFLP typing, c-DNA sequencing and the phylogenetic tree demonstrated the presence of all known 3 major genogroups – including two subgroups – within local samples (i.e., group 1 (n=1), 2a (n=11), 2b (n=4) and 3 (n=5)). The phylogenetic tree was supported by bootstrap analysis and confirmed the accuracy of the proposed RFLP method (Quarleri et al., J. Clin. Microbiol., in press). Conclusions: 1. These data argues against a strict geographic distribution of GBV-C / HGV genetic groups as previously observed in other countries and depict a partial view of the molecular epidemiology of this virus in a risk population from Argentina. 2. A novel RFLP method for GBV-C / HGV classification appears to be useful for epidemiological studies.