Oral Presentation 9th Australasian Virology Society Meeting 2017

Proof-of-concept biosensor for the detection of Norovirus in oysters (#42)

Valeria A Torok 1 , Nekane Reta Murua 2 , Kate R Hodgson 1 , Nicolas H Voelcker 2 3 , Beatriz Prieto SImon 2
  1. Food Safety and Innovation, South Australian Research and Development Institute, Adelaide, SA, Australia
  2. Future Industries Institute, University of South Australia , Mawson Lakes, SA, Australia
  3. Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Vic, Australia

Foodborne gastroenteritis is a significant cost to society. Human norovirus (NoV) is the leading cause of non-bacterial gastroenteritis worldwide. Currently, the identification of NoV in foods (oysters, leafy greens and berries) is reliant on detection of the viral genome by PCR technology. Although this method offers the best sensitivity available for detection of foodborne contamination (<100 virus genomes per gram food matrix), it has the disadvantage that it does not distinguish between infective and non-infective virus particles, and may not be directly associated with foodborne risk. An electrochemical aptasensor based on a porous alumina membrane-modified gold electrode was developed for the detection and quantification of murine norovirus (MNV). As MNV is able to be cultured in-vitro, it was used as a surrogate for NoV and enabled investigations of infective virus to be undertaken. More importantly, biosensor functionality was demonstrated in oyster tissue extracts. The developed biosensor reported a limit of detection (LOD) of 10 pfu/mL in buffer and the sensitivity of detection far exceeded that observed for previous reported biosensors of norovirus or virus surrogates. Furthermore, the electrochemical aptasensor demonstrated application for detection in diluted oyster extract with an LOD of 52 pfu/mL and was able to quantify MNV in seeded oyster tissue at concentrations greater than 1,000 pfu/mL. Further work is required to optimise oyster extraction methodology to eliminate the need for oyster extract dilution prior to sensor application. Detection and quantification of MNV using the electrochemical aptasensor correlated with the detection of infectious virus by in-vitro cell culture. Specific advantages of a biosensor able to detect only infectious virus would be the reduction of “false” positives from non-infectious virus, which do not pose a health risk, and the potential for on-site real-time monitoring.