Prolonged Viral RNA Detection in the Central Nervous System of One-Week-Old Swiss Albino Mice following Coxsackievirus B4 and Echovirus 9 Infection

Objectives: Type B coxsackieviruses (CV-B), together with echoviruses (E), are among the most common pathogens encountered in aseptic meningitis and meningoencephalitis. They frequently infect the central nervous system (CNS). The mechanisms of virus spreading in the CNS are poorly understood. In the present study, we investigated CV-B4 and E-9 spreading and neurotropism within intraperitoneally inoculated one-week-old Swiss albino mice. Methods: Seminested RT-PCR and virus isolation were used to assay viral distribution. Results: Viral RNA was present in various organs: brain, spinal cord, spleen and heart at various times post-infection (p.i.); ranging from 1 day p.i. up to 30, 60 and 90 days p.i, respectively, for CV-B4-JVB-, E-9 Barty- and CV-B4-E2-infected mice. Organs became negative for virus isolation after 5 days p.i., except for brain and heart from CV-B4 E2-infected mice, which remained positive for up to 10 and 15 days p.i., respectively. Negative viral RNA strand was detected mainly in brain and spinal cord of infected mice until 30 and 60 days p.i. Conclusion: This is the first report on the persistence of CV-B4 and E-9 in the CNS of intraperitoneally inoculated mice.