Downloaded from www.microbiologyresearch.org by IP: 54.162.133.179 On: Tue, 09 Feb 2016 19:13:18 Complete genomes for hepatitis C virus subtypes 6f, 6i, 6j and 6m: viral genetic diversity among Thai blood donors and infected spouses Ling Lu, 1 Chunhua Li, 1,2 Yongshui Fu, 3 Lakkana Thaikruea, 4 Satawat Thongswat, 5 Niwat Maneekarn, 6 Chatchawann Apichartpiyakul, 6 Hak Hotta, 7 Hiroaki Okamoto, 8 Dale Netski, 9,10 Oliver G. Pybus, 11 Donald Murphy, 12 Curt H. Hagedorn 1 and Kenrad E. Nelson 9,10 Correspondence Ling Lu llu@kumc.edu Kenrad E. Nelson kenelson@jhsph.edu 1 Division of Gastroenterology/Hepatology, Department of Medicine, University of Kansas Medical Center, 4035 Delp, MS 1023, Kansas City, KS 66160, USA 2 The First People’s Hospital of Yunnan Province, Kunming, China 3 Gunagzhou Blood Center, Guangzhou City, Guangdong Province, China 4 Department of Community Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand 5 Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand 6 Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand 7 Department of Microbiology, Kobe University School of Medicine, Chuo-ku, Kobe, Hyogo 650, Japan 8 Division of Virology, Department of Infection and Immunity, Jichi Medical University School of Medicine, Tochigi-Ken, Japan 9 Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA 10 Department of Medicine, Johns Hopkins University, Baltimore, MD, USA 11 Department of Zoology, Oxford University, Oxford, UK 12 Institut National de Sante ´ Publique du Quebec, Laboratoire de Sante ´ Publique du Quebec, Sainte-Anne-de-Bellevue, Quebec, Canada Received 29 September 2006 Accepted 25 January 2007 In this study, the first complete genome sequences for hepatitis C virus (HCV) subtypes 6f, 6i, 6j and 6m, obtained from infected blood donors in Chiang Mai, Thailand, are reported. Pairwise genome-wide nucleotide similarities between some of these isolates were higher than the 75–80 % value used previously to define different HCV subtypes. To investigate further, the entire genomes of four prototype isolates, Th602 (6i), Th553 (6j), B4/92 (6m) and D86/93 (6n), were sequenced. Pairwise comparison of these sequences gave a similar range of nucleotide similarities, thereby providing new information for HCV subtype classification. In order to study the hypothesis of interspousal HCV transmission, four additional complete HCV genome sequences were obtained from two infected Thai blood donors and their spouses, C-0044 and C-0046 (6f), and C-0192 and C-0185 (6m). Pairwise comparison of the sequences revealed that C-0044 and C-0046 share a nucleotide similarity of 98.1 %, whilst C-0185 and C-0192 have a similarity of 97.8 %. Several other studies of partial HCV sequences of different genomic regions from HCV-infected couples have shown nucleotide similarities ranging from 96.3 to 100 %. The similarities of the complete genome sequences from the two couples in the current study are consistent with HCV transmission between spouses. The GenBank/EMBL/DDBJ accession numbers for the sequences reported in this study are DQ835760–DQ835770. Supplementary tables showing PCR primers and amplification strategy, and origin of the retrieved sequences reanalysed are available in JGV Online. Journal of General Virology (2007), 88, 1505–1518 DOI 10.1099/vir.0.82604-0 0008-2604 G 2007 SGM Printed in Great Britain 1505