Characterization of Enteroviruses Isolated from Patients with Aseptic Meningitis

ABSTRACT

Enteroviruses (EVs) are human pathogens that cause a wide variety of clinical illnesses. The spectrum of the diseases ranges from a mild febrile illness to severe diseases such as meningitis or myocarditis. In the present study, we have used a reverse transcription-polymerase chain reaction method to detect EVs from patients with aseptic meningitis followed by typing of the EVs after HeLa cell culture isolation. In addition, twelve reference strains and the six clinical isolates of EVs were infected to neonatal rat cardiocytes and the viability of infected cells was measured by MTT assay. Marked inhibition of cell proliferation was observed in the cardiocytes cultures infected with coxsackievirus (CV) B1, CVB4, and CVB5, and two wild strains, whereas mild inhibition was observed from those infected with CVB2, CVB3, echoviruses 6, 7, 11, 22, 25, and 30. Recombinant plasmid containing full-length cDNA genome of the cardiovirulent wild strain was successfully constructed and its complete nucleotide sequence was determined. The genome showed characteristics of enteroviruses. The RNA genome was 7,391 nucleotides in length, with a 5'-nontranslating region (742 nucleotides) followed by an open reading frame (encoding a 2,182 amino acid polyprotein) and a 3'-nontranslating region (100 nucleotides) and polyadenylated tail. The predicted amino acid sequences of the polyprotein showed 89~95% homology with those of reference coxsackievirus strains (CVB1-5).