本研究报告了从印度城市地区救出的懒惰熊(Melursusursinus)中轮状病毒C(RVC)的检测和分子表征。基于RVCVP6基因靶向诊断RT-PCR检测,48.3%(42/87)的懒熊RVC感染检测呈阳性。进一步分析了三个树懒熊RVC分离株(UP-SB19、21和37)的VP6,VP7和NSP4基因。RVCUP-SB21和37个分离株的VP6基因仅有37%的同一性。序列同一性,TM-来自结构对齐的分数,猪和人RVC分离株的VP6UP-SB37的选择压力(dN/dS)为(99.67%,0.97和1.718)和(99.01%,0.93和0.0340),分别。然而,VP6UP-SB21有一个身份,TM分数,dN/dS为(84.38%,1.0和0.0648)和(99.63%,1.0和3.7696)与人和猪RVC分离株,分别。来自UP-SB19和37个RVC分离株的VP7基因具有79.98%的同一性和共有同一性,TM分数,dN/dS为88.4%,0.76和5.3210,以及77.98%,猪和人RVC分离株为0.77和4.7483,分别。UP-SB37RVC分离株的NSP4基因具有同一性,TM分数,dN/dS为98.95%,0.76和0.2907,以及83.12%,猪和人RVC分离株为0.34和0.2133,分别。对树懒熊RVC分离株的核苷酸序列进行系统发育分析,将分离株UP-SB37分配给基因型G12,I2用于RVC结构基因VP7和VP6,E1用于NSP4基因,分别,而分离株UP-SB19和UP-SB21分别根据结构基因VP7分为基因型G13和GI7。该研究表明,印度懒熊种群中流通的RVC差异很大,可能来自猪或人类,进一步的研究集中在树懒熊RVC分离株的全基因组测序可能会揭示病毒的起源和进化。
The present study reports the detection and molecular characterisation of rotavirus C (RVC) in sloth bears (Melursus ursinus) rescued from urban areas in India. Based on an RVC VP6 gene-targeted diagnostic RT-PCR assay, 48.3% (42/87) of sloth bears tested positive for RVC infection. The VP6, VP7, and
NSP4 genes of three sloth bear RVC isolates (UP-SB19, 21, and 37) were further analysed. The VP6 genes of RVC UP-SB21 and 37 isolates were only 37% identical. The sequence identity, TM-score from structure alignment, and selection pressure (dN/dS) of VP6 UP-SB37 with pig and human RVCs isolates were (99.67%, 0.97, and 1.718) and (99.01%, 0.93, and 0.0340), respectively. However, VP6 UP-SB21 has an identity, TM-score, and dN/dS of (84.38%, 1.0, and 0.0648) and (99.63%, 1.0, and 3.7696) with human and pig RVC isolates, respectively. The VP7 genes from UP-SB19 and 37 RVC isolates were 79.98% identical and shared identity, TM-score, and dN/dS of 88.4%, 0.76, and 5.3210, along with 77.98%, 0.77, and 4.7483 with pig and human RVC isolates, respectively. The
NSP4 gene of UP-SB37 RVC isolates has an identity, TM-score, and dN/dS of 98.95%, 0.76, and 0.2907, along with 83.12%, 0.34, and 0.2133 with pig and human RVC isolates, respectively. Phylogenetic analysis of the nucleotide sequences of the sloth bear RVC isolates assigned the isolate UP-SB37 to genotype G12, I2 for RVC structural genes VP7 and VP6, and E1 for
NSP4 genes, respectively, while isolates UP-SB19 and UP-SB21 were classified as genotype G13 and GI7 based on the structural gene VP7, respectively. The study suggests that the RVCs circulating in the Indian sloth bear population are highly divergent and might have originated from pigs or humans, and further investigation focusing on the whole genome sequencing of the sloth bear RVC isolate may shed light on the virus origin and evolution.