Figure 1

Phylogenetic tree analysis of the 15 "undetermined" viruses isolated in patients enrolled at the time of primary infection. In the phylogenetic trees, based on the RT nucleotide sequence of the 15 “undetermined” strains (a) and the corresponding V3-V5 env region for 13 of them (b), the reference sequences were as follows: 3 references for all pure subtypes, 1 reference for 18 previously described CRF (CRF01-16 and CRF18-19), and unique recombinant MAL [23], NOGIL [24] and 97CD-KTB49 [18] strains. Trees based on unambiguously aligned nucleotides were generated by the neighbour-joining method, and the reliability of each clustering was assessed by bootstrapping with one hundred replicates implemented by Clustal W. The Simplot v3.5.1 performed bootscanning on NJ trees along the genome alignment by moving a 400 base pairs window along the genome alignment with 20 base pairs increment and one hundred replicates for each phylogeny. Only bootstrap values above 70 at each of the internal branches defining a subtype are shown.