Influence of Environmental Conditions on Norovirus Presence in Mussels Harvested in Montenegro

This study comprises the first systematic survey of the occurrence of Norovirus in Mediterranean mussels from harvesting areas in Montenegro coast of Adriatic Sea. Mussels may accumulate contaminants of public health concern, including pathogenic bacteria and viruses. Microbiological monitoring of harvesting areas is based on count of Escherichia coli in bivalve molluscs in the European Union. It is assumed that E. coli does not reflect contamination with enteric viruses. A structured field study was undertaken at six locations in Bay of Kotor, Montenegro, in order to investigate plausible influence of environmental factors on the variability of E. coli and norovirus (NoV). From July 2015 to July 2016, a total of 72 samples of mussels were collected in coastal harvesting areas of the Montenegro. The samples were screened for NoV of genogroups GI and GII using reverse transcription-qPCR (RT-qPCR). There were 43% NoV positive samples with higher presence of genogroup GII (74.2%). With regard to influence of environmental conditions on Norovirus presence, we have proved seasonal pattern of virus occurrence i.e., the largest number of positive samples was noticed during winter, while other physico-chemical factors were not of great significance. It was found that count of E. coli did not correlate with Norovirus prevalence. From the aspect of food safety, an upgrade of monitoring plans could lead to obtaining safer products.