# Exploring an Aptamer-Based Approach to Assess Canine Parvovirus Integrity After Disinfection Treatment

## TL;DR

This study explores using DNA aptamers to detect changes in canine parvovirus after disinfection, offering a faster and more sensitive alternative to traditional methods.

## Contribution

The study introduces a novel aptamer-based method to differentiate between intact and inactivated canine parvovirus particles.

## Key findings

- Aptamers were enriched through SELEX and showed specific binding to denatured canine parvovirus.
- No binding was observed with feline panleukopenia virus or porcine parvovirus, indicating high specificity.
- PCR detection confirmed that the aptamers bind to heat- and PAA-treated CPV but not intact CPV.

## Abstract

Virus inactivation exhibits varying disinfection kinetics due to structural or genomic differences. Standard post-disinfection assessment relies on observing cytopathic effects in inoculated cell cultures, which are limited by sensitivity, availability, cost, and turnaround time. This study explores nucleic acid aptamers as molecular sensors to differentiate between intact and post-disinfection virus particles. To discover aptamers, 12 cycles of an automated SELEX (Systematic Evolution of Ligands by Exponential Enrichment) experiment were performed using recombinant (r)-VP2 protein of canine parvovirus (CPV). Enrichment of single stranded (ss) DNA binders was evaluated by sequencing the enriched libraries. The most abundant sequences were tested for binding with coated rVP2 and CPV (intact and treated with heat and peracetic acid (PAA) disinfectant) followed by detection using PCR. Binding specificity was assessed using intact and heat-treated feline panleukopenia virus (FPV) and porcine parvovirus (PPV). Sequencing of the DNA libraries from selection cycle 6 and cycle 12 products showed individual sequence enrichment with maximum frequencies of 2.14% and 8.65%, respectively. The top three abundant sequences from each cycle confirmed rVP2 binding. In the case of CPV, only heat-treated and PAA-treated CPV showed binding to the candidate sequences. However, reduced binding to the CPV-specific antibody was observed for rVP2 and treated CPV compared to intact CPV. No apparent binding of the tested sequences was observed for FPV and PPV. Aptamers binding to denatured but not intact CPV demonstrate the potential to distinguish between the two states, providing a basis for developing a molecular assay to assess disinfection efficacy.