Study on actual status of adult rotavirus infections in Southern Asia and Southeastern Asia

本研究的目的是表征引起南亚和东南亚地区成人腹泻疾病的轮状病毒。这项研究是与印度、孟加拉国、泰国和中国合作进行的。在2003年至2005年期间收集了腹泻患者的粪便标本。A组轮状病毒在儿童中的检出率为25-35%，而在成人中的检出率约为25-35%。1%到10%。在中国的这项研究中，来自儿童和成人的大多数轮状病毒株显示出相同的抗原类型。在孟加拉国（14例）和中国（2例）成人粪便标本中检测到B组轮状病毒。在印度，通过RT-PCR在约20%的儿童腹泻粪便标本中检测到B组轮状病毒。对来自各国的B组轮状病毒的系统发育分析表明，来自印度和孟加拉国的病毒在遗传上密切相关，但与中国的病毒不同。根据对中国病毒株的突变率估计，更多的用途和中国病毒被认为是从大约60-70年前的共同祖先病毒中分化出来的。在孟加拉国，发现了一种不寻常的轮状病毒毒株。该病毒在遗传上不同于已知的A、B和C组轮状病毒，可能代表一种新的轮状病毒种（组）。作为B组轮状病毒主要在成人中引起腹泻的特殊特性的研究，我们研究了非结构蛋白NSP4的序列多样性和存在的肠毒素活性，而肠毒素活性是引起动物腹泻的机制之一。结果表明，B组轮状病毒NSP4与a组轮状病毒NSP4具有高度的序列差异，但在哺乳小鼠中，c端附近的序列具有肠毒素活性。这些发现提示B组轮状病毒可能具有与A组轮状病毒相似的致人腹泻机制。少

The purpose of this study is to characterize rotaviruses which cause diarrheal diseases in adults in Southern Asian and Southeast Asian regions. This study was performed in collaboration with India, Bangladesh, Thailand, and China. Stool specimens were collected from diarrheal patients in a period between 2003 and 2005. While detection rate of group A rotavirus in children was 25-35%, detection rate in adult ranged from approx. 1% to 10%. In the study in China, most rotavirus strains from children and adults showed identical antigenic types. Group B rotavirus was detected in adult stool specimens in Bangladesh (14 specimens) and China (2 specimens). In India, group B rotavirus was detected by RT-PCR in about 20% of diarrheal stool specimens from children. Phylogenetic analysis of the group B rotaviruses from individual countries indicated that the viruses from India and Bangladesh were genetically closely related but distinct from Chinese viruses. The Indian-Bangladeshi group B rotavir … More uses and Chinese viruses were suggested to be diverged from a common ancestral virus approximately 60-70 years ago based on estimation of mutation rate calculated for Chinese virus strains. In Bangladesh, an unusual rotavirus strain was detected. This virus was genetically different from the known group A, B, and C rotaviruses, and suggested to represent a novel species (group) of rotavirus. As a study on special characteristic of group B rotavirus, i.e., causing diarrhea primarily in adults, nonstructural protein NSP4 was studied for its sequence diversity and presence of enterotoxin activity which is known as one of the mechanisms causing diarrhea in animals. As a result, group B rotavirus NSP4 exhibited high degree of sequence divergence from group A rotavirus NSP4, however, it was demonstrated that sequences near the C-terminal region possess enterotoxin activity in suckling mice. These findings suggested that group B rotavirus may have similar mechanisms for causing diarrhea in human to group A rotavirus. Less