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Updated: Aug 29, 2026
Particle Agglutination Method for Poliovirus Identification
Published on: April 20, 2011
Isolation and identification of a novel human parechovirus
Miyabi Ito1, Teruo Yamashita1, Hideaki Tsuzuki1
1Department of Microbiology, Aichi Prefectural Institute of Public Health, Nagare 7-6, Tsuji-machi, Kita-ku, Nagoya, Aichi 462-8576, Japan.
Abstract:
A cytopathic agent (A308/99) was isolated using Vero cells from a stool specimen of a 1-year-old patient with transient paralysis. The agent was approximately 28 nm in diameter with a distinct ultrastructure resembling the virus particle of an enterovirus. It could not be neutralized by antisera against human picornaviruses such as human enterovirus, Aichi virus or human parechovirus. The virion contained three capsid proteins with molecular masses of 38, 30.3 and 30 kDa. Determination of the complete nucleotide sequence of A308/99 revealed that the nucleotide and deduced amino acid sequences were closely related to those of human parechoviruses. When 11 regions encoding the structural and non-structural proteins were compared, A308/99 had between 75 and 97 % and 73 and 97 % nucleotide identity with human parechovirus type 1 (HPeV-1) and type 2 (HPeV-2), respectively. The most distinctive divergence was seen in VP1, which had 74.5 % and 73.1 % nucleotide identity with HPeV-1 and HPeV-2, respectively. Viruses related to A308/99 were also isolated from three patients with gastroenteritis, exanthema or respiratory illnesses. A308/99 and these other three isolates had no arginine-glycine-aspartic acid (RGD) motif, which is located near the C terminus of VP1 in HPeV-1 and HPeV-2. A seroepidemiological study revealed that the prevalence of A308/99 antibodies was low (15 %) among infants but became higher with age, reaching more than 80 % by 30 years of age. These observations indicate that A308/99 is genetically close to, but serologically and genetically distinct from, HPeV-1 and HPeV-2 and accordingly can be classified as third serotype of human parechovirus.
Insights
A new cytopathic agent, A308/99, was identified and found to be a novel human parechovirus serotype. This discovery expands our understanding of parechovirus diversity and associated illnesses.
Area of Science:
- Virology
- Molecular Biology
- Epidemiology
Background:
- A novel cytopathic agent, A308/99, was isolated from a patient with transient paralysis.
- The agent exhibited ultrastructural characteristics similar to enteroviruses but was distinct from known human picornaviruses.
Purpose of the Study:
- To characterize the novel cytopathic agent A308/99.
- To determine its genetic and serological relationship to known human parechoviruses.
Main Methods:
- Vero cell culture for isolation and propagation.
- Electron microscopy for ultrastructural analysis.
- Nucleotide sequencing for genetic comparison.
- Serological assays to assess antibody prevalence.
Main Results:
- A308/99 shares significant nucleotide and amino acid sequence identity with human parechovirus types 1 and 2 (HPeV-1, HPeV-2).
- Distinct divergence was observed in the VP1 gene, and the absence of the RGD motif.
- Related viruses were isolated from patients with gastroenteritis, exanthema, and respiratory illnesses.
- Seroepidemiological data showed increasing antibody prevalence with age, indicating widespread circulation.
Conclusions:
- A308/99 represents a new, third serotype of human parechovirus.
- This finding expands the known spectrum of human parechovirus infections.
- The lack of the RGD motif may influence viral pathogenesis and tissue tropism.
