How Safe to Eat Are Raw Bivalves? Host Pathogenic and Public Health Concern Microbes within Mussels, Oysters, and Clams in Greek Markets

Abstract

Raw-bivalves consumption is a wide trend in Mediterranean countries. Despite the unambiguous nutritional value of seafood, raw consumption of bivalves may involve risks that could pose a significant threat to consumers’ health. Their filter-feeding behavior is responsible for the potential hosting of a wide variety of microorganisms, either pathogenic for the bivalves or public health threats. Under this prism, the current study was conducted in an effort to evaluate the risk of eating raw bivalves originating from the two biggest seafood markets in Thessaloniki, the largest production area of bivalves in Greece. Both microbiological and molecular methodologies were applied in order to assess the presence of various harmful microbes, including noroviruses, Bonamia, Marteilia, Esherichia coli, Salmonella, and Vibrio. Results indicated the presence of several Vibrio strains in the analyzed samples, of which the halophilic Vibrio harveyi was verified by 16S rRNA sequencing; other than this, no enteropathogenic Vibrio spp. was detected. Furthermore, although Esherichia coli was detected in several samples, it was mostly below the European Union (EU) legislation thresholds. Interestingly, the non-target Photobacterium damselae was also detected, which is associated with both wound infections in human and aquatic animals. Regarding host pathogenic microorganisms, apart from Vibrio harveyi, the protozoan parasite Marteilia refrigens was identified in oysters, highlighting the continuous infection of this bivalve in Greece. In conclusion, bivalves can be generally characterized as a safe-to-eat raw food, hosting more bivalve pathogenic microbes than those of public health concern.

Are Marine Heatwaves Responsible for Mortalities of Farmed Mytilus galloprovincialis? A Pathophysiological Analysis of Marteilia Infected Mussels from Thermaikos Gulf, Greece

“…PCR products were visualized in an agarose gel after electrophoresis stained with ethidium bromide. A previously identified Marteilis refrigens sample [ 53 ] was utilized in each reaction as a positive control. Positive samples were cleaned using the NucleoSpin Gel and PCR Clean-up kit (Macherey Nagel, Düren, Germany) and bidirectionally sequenced for identification of the species.…”

Metatranscriptomics unmasks Mollusca virome with a remarkable presence of rhabdovirus in cephalopods

“…Their study has become relevant because they are valuable as bioindicators (Chaudhary et al, 2022;De Silva et al, 2022;Goncalves et al, 2022;Jong et al, 2022;Lemos et al, 2022;Pokhrel et al, 2022) and because many mollusk species are important in the aquaculture industry, as is the case for mussels, oysters, clams and abalones, representing 23% of total aquaculture production (FAO, 2022). It is important to highlight the habit of consuming some uncooked food, being a potential risk for human health (Prato et al, 2004;Guyader et al, 2008;Lattos et al, 2021). Well-demonstrated cases of norovirus, causing gastroenteritis and hepatitis A virus, highlight the importance of detection in samples of commercial interest.…”

Histopathology and Phylogeny of the Dinoflagellate Hematodinium perezi and the Epibiotic Peritrich Ciliate Epistylis sp. Infecting the Blue Crab Callinectes sapidus in the Eastern Mediterranean

“…Global invasions, i.e., the successful establishment, breeding, and spreading of organisms outside of their natural range, may have detrimental consequences on local ecosystems. Invasions in aquatic ecosystems are increasingly frequent and are responsible for pressure on local habitats, posing a risk to biodiversity by spreading pathogenic microorganisms to the new ecosystems [ 1 , 2 ]. Climate change, shipping by the means of ballast waters, global trade, and accidental or intentional (for rearing purposes) releases of non-indigenous species into new ecosystems have intensified the phenomenon in recent years, affecting local flora and fauna [ 3 , 4 , 5 , 6 , 7 , 8 ].…”