title: Characterization of drug-resistance mutations in HIV type 1 isolates from drug-naive and ARV-treated patients in Bulgaria.
abstract: Little information is available about the prevalence of resistance mutations to reverse transcriptase (RT) and protease (PR) inhibitors of HIV-1, after the introduction of antiretroviral treatment in Bulgaria. To fill this gap, we analyzed 80 plasma samples from HIV-1-infected Bulgarian patients, 22 naive at antiretroviral treatment (ARV) and 58 ARV experienced. The subtypes B and A resulted in the two most prevalent (41 patients and 18 patients, respectively). The proportion of subtype B among naive and treated patients was similar in each group (57% vs. 47%, p = 0.62), while a major proportion of subtypes A was present in drug-naive patients rather than in treated patients [8/22 (36.4%) vs. 10/58 (17.2%), p = 0.08]. Two (9.1%) naive patients and 40 (70.1%) drug-experienced patients had viruses carrying at least one mutation conferring resistance to ARV drugs. Of 57 patients having experience with nucleoside reverse transcriptase inhibitors (NRTI), 32 (56.1%) had NRTI resistance mutations; 8/14 (57.2%) patients having experience with non-NRTI (NNRTI) had viruses carrying NNRTI resistance mutations; and 21/46 (45.7%) patients having experience with protease inhibitors (PI) had PI resistance mutations. The commonest resistance mutations resulted in the NRTI mutation M184V (42.1%) and the PI mutation L90M (24.1%). In conclusion, due to the detection of the substantial transmission of resistant variants to newly infected individuals, continuous surveillance is required, since greater access to highly active antiretroviral therapy (HAART) will be expected in Bulgaria. Furthermore, surveillance of PR and RT sequences is also convenient to monitor the introduction of nonsubtype B HIV-1 strains in Bulgaria.
authors.affiliation: Department of Experimental Medicine and Biochemical Sciences, University of Rome Tor Vergata, Rome, Italy.
authors.forename: Maria Mercedes
authors.initials: MM
authors.lastname: Santoro
authors.forename: Massimo
authors.initials: M
authors.lastname: Ciccozzi
authors.forename: Claudia
authors.initials: C
authors.lastname: Alteri
authors.forename: Stefania
authors.initials: S
authors.lastname: Montieri
authors.forename: Ivailo
authors.initials: I
authors.lastname: Alexiev
authors.forename: Iordanka
authors.initials: I
authors.lastname: Dimova
authors.forename: Francesca
authors.initials: F
authors.lastname: Ceccherini-Silberstein
authors.forename: Danail
authors.initials: D
authors.lastname: Beshkov
authors.forename: Giovanni
authors.initials: G
authors.lastname: Rezza
authors.forename: Carlo Federico
authors.initials: CF
authors.lastname: Perno
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D002031:Bulgaria; D024882:Drug Resistance, Viral; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000821:virology*; D016333:HIV Protease / Q000235:genetics; D017320:HIV Protease Inhibitors / Q000627:therapeutic use; D054303:HIV Reverse Transcriptase / Q000235:genetics; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D010949:Plasma / Q000821:virology; D012367:RNA, Viral / Q000235:genetics; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use; D017422:Sequence Analysis, DNA
chemical_list: D044966:Anti-Retroviral Agents; D017320:HIV Protease Inhibitors; D012367:RNA, Viral; D018894:Reverse Transcriptase Inhibitors; C514824:reverse transcriptase, Human immunodeficiency virus 1; D054303:HIV Reverse Transcriptase; D016333:HIV Protease; C514803:p16 protease, Human immunodeficiency virus 1
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