[Postmortem Molecular Epidemiology of HIV-1 Strains Isolated in Turkey]

Human immunodeficiency virus (HIV) comprises two genotypes, namely HIV-1 (group M, N, O and P) and HIV-2 (group A to H), which differ in their envelope glycoproteins and other antigenic epitopes despite their morphological and biological resemblance.Group M of HIV-1 responsible for 95% of HIV infections worldwide is composed of nine subgroups. In addition to subgroups, group M contains also two recombinant forms, known as circulating recombinant form (CRF) and unique recombinant form (URF). The first case of HIV/acquired immun deficiency virus (AIDS) in Turkey was reported in 1985 and the current number of cases reached a total of 18.557 including 1736 with AIDS based upon the surveillance data of Ministry of Health between October 1985 and November 2018. The aim of this study was to determine the prevalence of HIV-1 strains isolated from HIV positive autopsy cases detected by HIV polymerase chain reaction (PCR) and determine drug resistance. Twenty eight cases [17 males, 11 female: age ranged between 3 months and 66 years (median: 35 years)] found to be HIV positive among the autopsy cases sent for HIV1 PCR study and serological screening between 2011-2017 were recruited in the study. For identification of subtypes in HIV-1 isolates, most-preferred analysis tool was used [HIVdb Stanford University Genotypic Resistance Interpretation Algorithm (www.hivdb.stanford.edu)]. Phylogenetic tree was made according to direct sequencing of HIV-1 reverse transcriptase (pol) region and phylogenetic analysis was evaluated in 23 cases. Los Alamos National Laboratory were trimmed from full-length genomes. Phylogenetic analysis of the 870 base pair of the pol gene region was performed using CLC Sequence Viewer v8.0 (Qiagen Aarhus A/S, www.qiagenbioinformatics.com) software. The phylogenetic tree was obtained according to the neighbor-joining method and the Jukes-Cantor nucleotide distance scale and bootstrap value was set at 1000. In our study, subtype B was found to be most frequent type (39.3%; 11/28). Subtype A (17.9%; 5/28), CRF02_AG (14.3%; 4/28), subtype C (10.7%; 3/28), B+CRF02_AG recombinant (3.6%; 1/28), CRF01_AE (3.6%; 1/28), subtype D (3.6%; 1/28), as well as subtype F (3.6%; 1/28) and subtype G (3.6%; 1/28) strains were also detected in the circulation. Analysis of our results showed that 32.1% (9/28) of the samples exhibited resistance mutations. Detected mutations were as follows: M41L, T215C, K65R, M184V, responsible for nucleoside reverse transcriptase inhibitor (NRTI) resistance; K103N, Y181C, G190A, responsible for non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance; D30N, M46I, responsible for protease inhibitor (PI) resistance. NRTI, NNRTI and PI mutation rates in the samples were found as 21.4%, 7.1% and 3.6%, respectively. Although number of samples analyzed in our study is low, we can propose that they resemble the strains circulating in Turkey. The results of our study; although the subtype B is still dominant in our country, it supports other studies reporting that there are non-B subtypes and an increase in CRF rates in recent years. Phylogenetic analysis is widely regarded as the gold standard technique to determine the subtypes of HIV-1. Molecular epidemiologic studies related to HIV may be important in monitoring HIV subtype patterns and spreading pathways in that country. As a result; the opportunity to collect postmortem HIV sequences in a database appears to have occurred, and as this database expands, its usability is available. Therefore, it is thought that HIV subtypes and mutation information may be useful.