Establishment and application of a wild neonatal mouse model infected with an Echovirus 30 isolate.

Abstract

Background: Echovirus 30 (E30) is a significant pathogen associated with various illnesses such as viral meningitis, viral myocarditis. Currently, there are no specific drugs or vaccines targeting this virus. An appropriate animal model is imperative for assessing drug and vaccine efficacy.

Methods: This investigation aimed to establish a neonatal mouse model using a clinical isolate E30/A538 and apply it to screen anti-E30 drugs. The study involved evaluating the susceptibility of different mouse strains to the isolate, determining the infectious dose, transmission route, and optimal age of the mice. This model was then used to assess antiviral efficacy.

Results: Neonatal ICR mice infected intracranially with 5LD₅₀ of E30/A538 at one-day-old displayed clinical symptoms such as tremors, lethargy, limb paralysis, and mortality. Importantly, the E30/A538-infected mice exhibited brain neuron apoptosis and severe myocardial necrolysis, closely resembling human infections. Elevated levels of viral RNA and positive antigen presence were predominantly detected in the brains and hearts of infected mice. Using this model to assess antiviral efficacy, it was demonstrated that interferon-α2a inhibited E30/A538 replication in vivo, mitigated histopathological changes in the brain, spinal cord, and myocardium, and enhanced the survival rate of neonatal mice.

Conclusions: In summary, this research established a wild neonatal mouse model of E30/A538 isolate infection that mirrors the characteristics of human infection. The model demonstrated the efficacy of interferon-α2a in combating E30. This model would serve as a foundation for investigating the pathogenesis of E30, as well as for assessing the efficacy of vaccines and other antiviral treatments against E30.