Comparison and optimization of detection methods for enveloped virus in vegetables
Comparison and optimization of detection methods for enveloped virus in vegetables
Maedeh Rafieepoor,1Seyed Reza Mohebbi,2,* Seyed Masoud Hosseini,3Mohammad Tanhaei,4Mahsa Saeedi Niasar,5Hamid AsadzadehAghdaei,6
1. Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran 2. Research Center for Gastroenterology and Liver Diseases, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran 3. Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran 4. Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran 5. Research Center for Gastroenterology and Liver Diseases, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran 6. Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Introduction: Studies around the world show that many gastrointestinal outbreaks in communities are caused by
the consumption of fruits and vegetables contaminated with enteric viruses such as Noroviruses,
HAV, HEV, Sapovirus and etc. Limited methods have been reported for enteric virus detection
from the surface of vegetables, however they usually showed a low viral recovery rate. These
techniques have also been limited to non-envelop viruses. Recently, with regard to the prevalence
of SARS-CoV-2, and the observation of some gastrointestinal complications such as diarrhea,
vomiting, etc. in patients with Covid-19, it is necessary to develop and evaluate the concentration
methods for enveloped viruses. The present study was performed to investigate and optimize the
current methods for concentrating and detecting enveloped viruses.
Methods: To investigate and optimize a method for detecting enveloped viruses, two concentrations of
TGBE and PEG were used to precipitate the viral particles. In this survey, a model virus called
avian infected bronchitis (IBV) was used to evaluate the recovery percentage. A certain amount of
IBV was inoculated into the lettuce leaf sample and its recovery was quantitatively calculated by
a specific primer set that was designed based on SYBR GREEN RT-qPCR assay and the recovery
percentage of each method was calculated and evaluated by standard curve. All analyzes were
performed in duplicate. Along with reviewing the methods, a sample without viral inoculation
(negative control sample) and a direct vaccine sample (positive control sample) were tested for
quality control.
Results: In four compared methods, the method that using, TGBE 3% and PEG 10%, has the highest
efficiency (22.4%) for detecting enveloped viruses from the surface of lettuce leaves. However,
other methods with lower IBV recovery rates are able to detect these group of viruses.
Conclusion: Our results show that higher concentration of TGBE could better wash the virus from the surface
of lettuce leaves, while lower concentration of PEG has better results and this method is an optimal
method with a good recovery rate for the detection of enveloped viruses.