Boriskin Y S, Bakir T M, al-Aska A I, Booth J C
Department of Medical Microbiology, St. George's Hospital Medical School, London, UK.
New Microbiol. 1999 Jul;22(3):173-80.
Hepatitis C virus (HCV) genotype 4 is believed to be predominant in the Middle East including Saudi Arabia (SA). We attempted to genotype 80 HCV isolates from different parts of SA by direct sequencing of a variable 222bp fragment from the NS5B region. The phylogenetic analysis of the NS5B sequences was complemented by direct sequence analysis of the conserved 5'-NCR region for HCV type-specific polymorphism. All 80 NS5B sequences separated into 3 clades which comprised 6 type 1b variants, 30 type 4 variants (24 of type 4a and 6 of type 4c or d) and 44 type 3 variants. Apart from two definitive type 3b variants the other 42 type 3 NS5B sequences formed 4 clusters with low similarity to type 3a-f HCV sequences from the database. The precise subtyping of these 42 type 3 variants awaits sequencing of longer HCV RNA stretches. Our results indicate that HCV type 4 may not be the only dominant genotype in SA.
丙型肝炎病毒（HCV）基因型4被认为在包括沙特阿拉伯（SA）在内的中东地区占主导地位。我们试图通过对NS5B区域一个222bp可变片段进行直接测序，对来自沙特不同地区的80株HCV分离株进行基因分型。对NS5B序列的系统发育分析通过对HCV类型特异性多态性的保守5'-NCR区域进行直接序列分析得到补充。所有80个NS5B序列分为3个进化枝，其中包括6个1b型变体、30个4型变体（24个4a型和6个4c或d型）以及44个3型变体。除了两个确定的3b型变体，其他42个3型NS5B序列形成了4个簇，与数据库中3a - f型HCV序列的相似性较低。这42个3型变体的确切亚型有待对更长的HCV RNA片段进行测序。我们的结果表明，HCV 4型可能不是沙特唯一的优势基因型。
