Kirkwood Carl, Bogdanovic-Sakran Nada, Palombo Enzo, Masendycz Paul, Bugg Helen, Barnes Graeme, Bishop Ruth
Department of Gastroenterology and Clinical Nutrition, Murdoch Childrens Research Institute, Royal Children's Hospital, Vctoria, Australia 3052.
J Clin Microbiol. 2003 Aug;41(8):3649-54. doi: 10.1128/JCM.41.8.3649-3654.2003.
Rotavirus serotype G9 is recognized as the most widespread of the emerging serotypes, emerging since 1996 as a frequent cause of severe acute gastroenteritis in children from many countries covering all continents of the world. This study characterized serotype G9 strains collected in three widely separated Australian centers from 1997 to 2001. All G9 strains possessed the VP4 P[8] and VP6 subgroup II genes. The overall prevalence of the G9 strains increased in Australia, from 0.6% of the strains found in 1997 to 29% of the strains found in 2001. The prevalence of G9 relative to all other serotypes varied from year to year and with geographic location. In Melbourne (representing east coast urban centers), G9 made up 11 to 26% of all of the strains found from 1999 to 2001. In Perth (representing west coast urban centers), G9 made up less than 2% of the strains found in 1997 to 2000 but increased to 18.6% of the strains found in 2001. In Alice Springs (representing widely dispersed settlements in northern arid regions), G9 made up 0 to 5% of the strains found from 1997 to 2000 and was the dominant strain in 2001, making up 68.9% of all of the strains found. Three distinct antigenic groups based on reaction with neutralizing monoclonal antibodies (N-MAbs) were identified, including a dominant group (63%) that cross-reacted with the serotype G4 N-MAb. Phylogenetic analysis of the VP7-encoding gene from Australian strains, compared with a worldwide collection of G9 strains, showed that the Australian G9 strains made up a genetic group distinct from other serotype G9 strains identified in the United States and Africa. Future epidemiological studies of the occurrence of G9 strains should combine reverse transcription-PCR and typing with G1 to G4 and G9 N-MAbs to determine the extent of G9 and G4 cross-reactions among rotavirus strains, in order to assess the need to incorporate G9 strains into new candidate vaccines.
轮状病毒G9血清型被认为是新出现的血清型中分布最广泛的，自1996年以来，它在世界各大洲许多国家中频繁导致儿童严重急性胃肠炎。本研究对1997年至2001年在澳大利亚三个相距甚远的中心收集的G9血清型毒株进行了特征分析。所有G9毒株都具有VP4 P[8]和VP6 II亚群基因。G9毒株在澳大利亚的总体流行率有所上升，从1997年发现的毒株的0.6%增至2001年发现的毒株的29%。G9相对于所有其他血清型的流行率随年份和地理位置而变化。在墨尔本（代表东海岸城市中心），1999年至2001年发现的所有毒株中G9占11%至26%。在珀斯（代表西海岸城市中心），1997年至2000年发现的毒株中G9占比不到2%，但在2001年增至18.6%。在爱丽丝泉（代表北部干旱地区广泛分布的定居点），1997年至2000年发现的毒株中G9占0%至5%，而在2001年它是优势毒株，占所有发现毒株的68.9%。基于与中和单克隆抗体（N-MAbs）反应确定了三个不同的抗原组，包括一个与血清型G4 N-MAb发生交叉反应的优势组（63%）。将澳大利亚毒株的VP7编码基因与全球收集的G9毒株进行系统发育分析表明，澳大利亚G9毒株构成了一个与在美国和非洲鉴定出的其他血清型G9毒株不同的遗传组。未来关于G9毒株出现情况的流行病学研究应结合逆转录PCR以及用G1至G4和G9 N-MAbs进行分型，以确定轮状病毒毒株中G9和G4交叉反应的程度，从而评估将G9毒株纳入新候选疫苗的必要性。
