Fig. 2

Frequency of amino acid sequence polymorphisms in the integrase gene with HIV-1HXB2 as the reference. Numbers below each position are the numbers of isolates with that specific polymorphism. Dark shaded boxes with white letters signify positions associated with primary resistance and lighter gray shaded boxes with black letters signify positions associated with secondary resistance as listed in the Stanford HIV Drug Resistance Database stated in September 2016. Dark gray boxes with black letters represent aa substitutions associated with INI resistance in vitro that occurred as natural polymorphisms [16, 20] found in our study. The N-terminal domain (NTD) is represented by AA acids at positions 1-50, the central core domain (CCD) at positions 51–212 and the C-terminal domain (CTD) at positions 213-288. The HHCC zinc-binding motif residues in the NTD are indicated by “*” and the DDE motif residues in the CCD are indicated by “•”