Differences in chemical contaminants bioaccumulation and ecotoxicology biomarkers in Mytilus edulis and Mytilus galloprovincialis and their hybrids

Mussels belonging to the Mytilus edulis species complex have been the focus of numerous studies exploring the systematics and origin of this commercially and ecologically important genus. Species have wide geographical ranges and hybridise where their distributions overlap, making identification difficult. Several molecular markers have been used to distinguish between the species within the M. edulis species complex; however, no single marker system has been found to be completely diagnostic, and a combination of markers are used. Here, we used a combination of three nuclear genes and a mitochondrial gene region to assess the species composition of Mytilus mussels collected across its geographical range in Australia. Our results show that the majority (98.5%) of individuals sampled from Australian populations are Mytilus galloprovincialis, with 56.2% of them displaying a southern hemisphere haplotype, 10.3% displaying a putatively northern hemisphere haplotype, and 32% having M. galloprovincialis genotypes consistent with either northern or southern hemisphere M. galloprovincialis lineages. The taxonomic origin of the remaining 1.5% of samples (n=3) could not be conclusively determined. Our results suggest that there have been significant introductions of non-native M. galloprovincialis lineages into both southern and northern hemisphere populations.

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Toxoplasma gondii and Other Zoonotic Protozoans in Mediterranean Mussel (Mytilus galloprovincialis) and Blue Mussel (Mytilus edulis): A Food Safety Concern?

Journal of Food Protection ◽

10.4315/0362-028x.jfp-18-157 ◽

2019 ◽

Vol 82 (3) ◽

pp. 535-542 ◽

Cited By ~ 5

Author(s):

TIZIANA TEDDE ◽

MARIANNA MARANGI ◽

ROBERTO PAPINI ◽

SARA SALZA ◽

GIOVANNI NORMANNO ◽

...

Keyword(s):

Toxoplasma Gondii ◽

Mytilus Edulis ◽

Mytilus Galloprovincialis ◽

Blue Mussel ◽

Safety Concern ◽

Giardia Duodenalis ◽

Cryptosporidium Spp ◽

Retail Outlets ◽

Mediterranean Mussel ◽

Foodborne Infection

ABSTRACT Mediterranean mussels (Mytilus galloprovincialis) and blue mussels (Mytilus edulis) are among the most consumed fishery products, but they are frequent vehicles of foodborne infection worldwide. In this study, we investigated the occurrence and seasonality of zoonotic protozoans in mussels farmed or sold at retail outlets in Italy. We collected and tested 1,440 M. galloprovincialis and 180 M. edulis. Pooled samples were molecularly tested for Giardia duodenalis, Cryptosporidium spp., and Toxoplasma gondii and then sequenced. Sixty-two (45.9%; 95% confidence interval, 37.5 to 54.3%) mussel pools tested positive for one or more of the investigated pathogens. Both Mytilus species and samples from all the investigated areas harbored pathogens. Mussels were statistically more contaminated by Cryptosporidium spp., followed by T. gondii and G. duodenalis assemblage A, and M. galloprovincialis was more contaminated than M. edulis (P < 0.01). Contamination was more likely in mussels at retail outlets (P < 0.05) than in those from farms and in mussels collected in spring (P < 0.01) than in other seasons. This is the first report of T. gondii found in M. galloprovincialis in Italy and in M. edulis in Europe. The detection of zoonotic protozoans in a widely consumed food source indicates the need for a more detailed microbiological risk analysis, especially considering that bivalve mollusks are often consumed raw worldwide.

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