Partial sequencing analysis of the NS5B region confirmed the predominance of hepatitis C virus genotype 1 infection in Jeddah, Saudi Arabia

Chronic hepatitis C virus (HCV) infection and its progression are major health problems that many countries including Saudi Arabia are facing. Determination of HCV genotypes and subgenotypes is critical for epidemiological and clinical analysis and aids in the determination of the ideal treatment strategy that needs to be followed and the expected therapy response. Although HCV infection has been identified as the second most predominant type of hepatitis in Saudi Arabia, little is known about the molecular epidemiology and genetic variability of HCV circulating in the Jeddah province of Saudi Arabia. The aim of this study was to determine the dominance of various HCV genotypes and subgenotypes circulating in Jeddah using partial sequencing of the NS5B region. To the best of our knowledge, this is the first study of its kind in Saudi Arabia. To characterize HCV genotypes and subgenotypes, serum samples from 56 patients with chronic HCV infection were collected and subjected to partial NS5B gene amplification and sequence analysis. Phylogenetic analysis of the NS5B partial sequences revealed that HCV/1 was the predominant genotype (73%), followed by HCV/4 (24.49%) and HCV/3 (2.04%). Moreover, pairwise analysis also confirmed these results based on the average specific nucleotide distance identity: ±0.112, ±0.112, and ±0.179 for HCV/1, HCV/4, and HCV/3, respectively, without any interference between genotypes. Notably, the phylogenetic tree of the HCV/1 subgenotypes revealed that all the isolates (100%) from the present study belonged to the HCV/1a subgenotype. Our findings also revealed similarities in the nucleotide sequences between HCV circulating in Saudi Arabia and those circulating in countries such as Morocco, Egypt, Canada, India, Pakistan, and France. These results indicated that determination of HCV genotypes and subgenotypes based on partial sequence analysis of the NS5B region is accurate and reliable for HCV subtype determination.

慢性丙型肝炎病毒（HCV）感染及其病情进展是包括沙特阿拉伯在内的诸多国家共同面临的重大公共卫生问题。明确丙型肝炎病毒基因型与亚型，对于流行病学及临床分析至关重要，可辅助确定最优治疗方案并预判治疗应答效果。尽管丙型肝炎病毒感染已被确定为沙特阿拉伯第二大高发病毒性肝炎类型，但针对沙特阿拉伯吉达地区流行的丙型肝炎病毒的分子流行病学特征与遗传变异情况，目前尚缺乏相关研究。本研究旨在通过对非结构蛋白5B（NS5B）基因区域进行部分测序，明确沙特阿拉伯吉达地区流行的各类丙型肝炎病毒基因型与亚型的分布优势。据我们所知，本研究是沙特阿拉伯地区同类研究中的首例。为明确丙型肝炎病毒的基因型与亚型，本研究收集了56例慢性丙型肝炎病毒感染者的血清样本，对其NS5B基因进行部分扩增并开展序列分析。对NS5B基因部分序列的系统发育分析结果显示，HCV/1为优势基因型（占比73%），其次为HCV/4（24.49%）与HCV/3（2.04%）。此外，基于平均核苷酸特异距离同一性的两两序列比对分析也验证了上述结果：HCV/1、HCV/4与HCV/3的平均核苷酸特异距离同一性分别为±0.112、±0.112与±0.179，且各基因型间未出现交叉干扰。值得注意的是，针对HCV/1亚型的系统发育树分析显示，本研究纳入的所有分离株（100%）均属于HCV/1a亚型。本研究结果同时显示，沙特阿拉伯地区流行的丙型肝炎病毒核苷酸序列，与摩洛哥、埃及、加拿大、印度、巴基斯坦及法国等国家流行的病毒序列具有较高同源性。上述结果表明，通过对NS5B基因区域进行部分序列分析以明确丙型肝炎病毒基因型与亚型，其结果准确可靠，可用于丙型肝炎病毒亚型的鉴定。