title: Zero prevalence of primary drug resistance-associated mutations to protease inhibitors in HIV-1 drug-naive patients in and around Aligarh, India.
abstract: BACKGROUND
  This study aimed to evaluate the prevalence of resistance mutations in the protease gene of HIV-1 strains isolated from north Indian antiretroviral (ARV) treatment-naive patients and to assess the phylogenetic relatedness of these strains with known HIV-1 strains.
  
  
  METHODS
  Fifty-four HIV-1 strains isolated from treatment-naive patients (n = 54) were included in this study. Resistance genotyping for the protease gene was performed using semi-nested PCR and DNA sequencing. The sequences were aligned (ClustalW) and a phylogenetic tree was built (MEGA 4 software). Drug resistance (DR) pattern was analyzed using the Stanford HIV-DR database and the IAS-USA mutation list. For subtyping purposes, all the nucleotide sequences were submitted to the REGA HIV-1 subtyping tool version 2.0l.
  
  
  RESULTS
  All the strains (100%) were found to belong to the C subtype and to harbor at least two secondary mutations in the protease gene. The most frequent mutations were H69K and I93L (52 of 52 strains), followed by I15V (80.7%), L19I (69.2%), M36I (67.3%), R41K (94.2%), L63P (61.5%), and L89M (82.7%).
  
  
  CONCLUSIONS
  This study confirms that HIV-1 subtype C predominates in northern India. Protease secondary mutations associated with drug resistance to protease inhibitors (PIs) were present with high frequency in the HIV-1 C subtype strains isolated from north Indian ARV treatment-naive patients, but no primary resistance mutations were found in this region. We suggest that resistance testing in HIV-1 infected patients should ideally be performed before the initiation of therapy to tailor the treatment for the individual to achieve the optimal therapeutic outcome.
authors.affiliation: J.N.M.C., Faculty of Medicine, Aligarh Muslim University, Aligarh, India. mdazam25@gmail.com.
authors.forename: Mohd
authors.initials: M
authors.lastname: Azam
authors.forename: Abida
authors.initials: A
authors.lastname: Malik
authors.forename: Meher
authors.initials: M
authors.lastname: Rizvi
authors.forename: Arvind
authors.initials: A
authors.lastname: Rai
mesh_terms: D000328:Adult; D024882:Drug Resistance, Viral; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000453:epidemiology / Q000821:virology*; D016333:HIV Protease / Q000235:genetics*; D017320:HIV Protease Inhibitors / Q000494:pharmacology*; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D020125:Mutation, Missense; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D015995:Prevalence; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D017320:HIV Protease Inhibitors; D016333:HIV Protease; C514803:p16 protease, Human immunodeficiency virus 1