Differences in replication capacity between enterovirus 71 isolates obtained from patients with encephalitis and those obtained from patients with herpangina in Taiwan

The cellular-tropism and biological characteristics of enterovirus 71 (EV71) isolates in Taiwan (TW) were studied. Growth curve experiments were conducted using cell lines that were possibly exhibited pathogenesis, and RT-PCR and sequencing tests were undertaken to amplify the 5' non-coding region (5'-NCR). The encephalitis isolate EV71 TW98NTU2078 was PBMCtropic, temperature-resistant (Tr) at 40 degrees C, and easier to replicate in HTB-14 (astrocytoma) than the herpangina isolate EV71 TW98NTU 1186 (The viral yields were 100-fold higher than those of the herpangina isolate EV71 TW98NTU 1186 at 96 hr post infection.). The herpangina isolate EV71 TW98NTU 1186 was non-PBMC-tropic, and temperature-sensitive (Ts) at 40 degrees C. The replication of EV71 TW98NTU1186 in HTB-14 was lower. No EV71 isolate infected HTB-37 (human colon adenocarcinoma cells). The encephalitis EV71 isolate exhibited better replication and transmission in PBMCs and astrocytes than did the EV71 isolate without CNS involvement.