Partial sequencing of the VP2 capsid gene for direct enterovirus genotyping in clinical specimens

Laboratory diagnosis of nonpolio enteroviruses: A review of the current literature

Infections by nonpolio enteroviruses (EVs) are highly prevalent, particularly among children and neonates, where they may cause substantial morbidity and mortality. Laboratory diagnosis of these viral infections is important in patient prognosis and guidance of clinical management. Although the laboratory diagnosis of nonpolio EVs is mainly based on molecular techniques, classical virus-isolation techniques are still used in reference laboratories. Other techniques, such as antigen detection and serology, are becoming obsolete and rarely used in diagnosis. An important part of diagnosis and surveillance of EV infections is viral typing by VP1 gene sequencing using conventional Sanger technique and more recently, full-genome next-generation sequencing. The latter allows the typing of all EVs, better investigation of EV outbreaks, detection of coinfection, and identification of severity markers in the EV genome.

Precise genotyping and recombination detection of Enterovirus

Enteroviruses (EV) with different genotypes cause diverse infectious diseases in humans and mammals. A correct EV typing result is crucial for effective medical treatment and disease control; however, the emergence of novel viral strains has impaired the performance of available diagnostic tools. Here, we present a web-based tool, named EVIDENCE (EnteroVirus In DEep conception, http://symbiont.iis.sinica.edu.tw/evidence), for EV genotyping and recombination detection. We introduce the idea of using mixed-ranking scores to evaluate the fitness of prototypes based on relatedness and on the genome regions of interest. Using phylogenetic methods, the most possible genotype is determined based on the closest neighbor among the selected references. To detect possible recombination events, EVIDENCE calculates the sequence distance and phylogenetic relationship among sequences of all sliding windows scanning over the whole genome. Detected recombination events are plotted in an interactive figure for viewing of fine details. In addition, all EV sequences available in GenBank were collected and revised using the latest classification and nomenclature of EV in EVIDENCE. These sequences are built into the database and are retrieved in an indexed catalog, or can be searched for by keywords or by sequence similarity. EVIDENCE is the first web-based tool containing pipelines for genotyping and recombination detection, with updated, built-in, and complete reference sequences to improve sensitivity and specificity. The use of EVIDENCE can accelerate genotype identification, aiding clinical diagnosis and enhancing our understanding of EV evolution.