Objective: To identify and describe the genetic characteristics of non-polio enteroviruses (NPEVs) which could multiplicated on L20B cell line, and discuss the impact to isolation rate of polioviruses.
Methods: 5 L20B positive isolates were collected from stool samples of patient with acute flaccid paralysis (AFP) and health children in Guangxi Zhuang autonomous region and Ningxia Hui autonomous region. These isolates were analysed using VP4 nucleotide sequencing method. The completed VP, coding regions were amplified and sequenced. Finally, phylogenetic tree were constructed base on completed VP1 coding regions sequences of these L20B positive isolates and those downloaded form GenBank database.
Results: The 5 NPEVs were all identified as coxsackieviruses group A (CVA). Among them, 1 was identified as CVA4, 1 was identified as CVA8 and 3 were identified as CVA10, and all of them belonged to human enterovirus species A (HEV-A). Nucleotide homology analysis and phylogenetic analysis base on completed VP1 coding regions sequences showed that all these 3 serotypes of NPEVs clustered independently, and they were all native circulated viruses in mainland China.
Conclusions: 5 NPEVs in this study belonged to HEV-A, covered 3 serotypes, CVA4, CVA8 and CVA10. Due to the high sensitivity of primarily inoculation of poliovirus onto L20B cell, the isolation rate of polioviruses could not be affected so much. Hand, foot, and mouth disease (HFMD) outbreaks in mainland China in recent years, and it was found that HEV-A is also pathogen of HFMD. Identification of these viruses have current significance to differential diagnosis of poliovirus infection and HFMD control and prevention.