doi:10.3390/v13010093engCañada, J.E.Delgado, E.Gil, H.Sánchez, M.Benito, S.García-Bodas, E.Gómez-González, C.Canut-Blasco, A.Portu-Zapirain, J.Sáez de Adana, E.De la Peña, M.Ibarra, S.Cilla, G.Iribarren, J.A.Martínez-Sapiña, A.Thomson, M.M.Identification of a New HIV-1 BC Intersubtype Circulating Recombinant Form (CRF108_BC) in SpainART-2021-123274The extraordinary genetic variability of human immunodeficiency virus type 1 (HIV-1) group M has led to the identification of 10 subtypes, 102 circulating recombinant forms (CRFs) and numerous unique recombinant forms. Among CRFs, 11 derived from subtypes B and C have been identified in China, Brazil, and Italy. Here we identify a new HIV-1 CRF_BC in Northern Spain. Originally, a phylogenetic cluster of 15 viruses of subtype C in protease-reverse transcriptase was identified in an HIV-1 molecular surveillance study in Spain, most of them from individuals from the Basque Country and heterosexually transmitted. Analyses of near full-length genome sequences from six viruses from three cities revealed that they were BC recombinant with coincident mosaic structures different from known CRFs. This allowed the definition of a new HIV-1 CRF designated CRF108_BC, whose genome is predominantly of subtype C, with four short subtype B fragments. Phylogenetic analyses with database sequences supported a Brazilian ancestry of the parental subtype C strain. Coalescent Bayesian analyses estimated the most recent common ancestor of CRF108_BC in the city of Vitoria, Basque Country, around 2000. CRF108_BC is the first CRF_BC identified in Spain and the second in Europe, after CRF60_BC, both phylogenetically related to Brazilian subtype C strains.2021http://zaguan.unizar.es/record/9975410.3390/v13010093http://zaguan.unizar.es/record/99754oai:zaguan.unizar.es:99754info:eu-repo/grantAgreement/ES/ISCIII-AESI/PI16CIII-00033info:eu-repo/grantAgreement/ES/ISCIII-AESI/PI19CIII-00042info:eu-repo/grantAgreement/ES/ISCIII-RIS-FEDER/RD16ISCIII-0002-0004VIRUSES-BASEL 13, 1 (2021), 93 [13 pp]byhttp://creativecommons.org/licenses/by/3.0/es/info:eu-repo/semantics/openAccess