title: Circulation of multiple patterns of unique recombinant forms B/CRF02_AG in France: precursor signs of the emergence of an upcoming CRF B/02.
abstract: BACKGROUND
  HIV-1 group M is characterized by substantial genetic diversity, and includes nine subtypes, more than 45 circulating recombinant forms (CRFs), and numerous unique recombinant forms (URFs). In France, the epidemic is characterized by predominance of subtype B strains, increasing prevalence of non-B subtypes (CRF02_AG being the most prevalent) and increasing at-risk behaviour in the MSM population. The high prevalence and co-circulation of B and CRF02_AG strains in this population raise the possibility that recombinant forms might emerge and spread.
  
  
  METHODS
  Samples from seven patients (five being MSM) were selected on the basis of subtyping discordances in different regions. The pattern of each near full-length genome of the viruses was characterized. The relationships between the newly and previously described B/CRF02_AG URFs were analysed using phylogenetic networks. Single genome amplification was used to search for the parental strains and confirmation of the breakpoints.
  
  
  RESULTS
  Seven unique recombination patterns were identified, breakpoints being found throughout the genomes, with hotspots in pol and accessory genes. No link was observed with the previous forms, but the CRF02 regions of two new viruses indicated that they are phylogenetically associated, suggesting a common ancestral strain. No evidence of circulating parental strains was found.
  
  
  CONCLUSIONS
  This description of seven URFs involving subtype B and CRF02_AG highlights the growing complexity of HIV molecular epidemiology in France. These multiple patterns, found mostly in MSM, and the hypothesis of a better fitness of some recombinant strains, argue for a context that could lead to the genesis of CRFB/02_AG strains in France.
authors.affiliation: Laboratoire associé au CNR du VIH, hôpital Ch. Nicolle, CHU de Rouen, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Leoz
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Chaix
authors.forename: Constance
authors.initials: C
authors.lastname: Delaugerre
authors.forename: Claire
authors.initials: C
authors.lastname: Rivoisy
authors.forename: Laurence
authors.initials: L
authors.lastname: Meyer
authors.forename: Christine
authors.initials: C
authors.lastname: Rouzioux
authors.forename: François
authors.initials: F
authors.lastname: Simon
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Plantier
mesh_terms: D000328:Adult; D000368:Aged; D004274:DNA, Recombinant / Q000235:genetics* / Q000276:immunology; D005260:Female; D005602:France / Q000453:epidemiology; D005784:Gene Amplification / Q000502:physiology; D014644:Genetic Variation; D015658:HIV Infections / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D004274:DNA, Recombinant; D012367:RNA, Viral