Microbiological quality of blue mussels (Mytilus edulis) in Nunavik, Quebec: a pilot study

Abstract

This pilot study was aimed at documenting the presence of fecal indicators and enteric pathogens in blue mussels (Mytilus edulis) from 6 communities in Nunavik, Quebec. One to four 2 kg samples of mussels were collected at low tide in each community. Samples were investigated by enumeration methods for the fecal indicators enterococci, Escherichia coli, F-specific coliphages, Clostridium perfringens, and by molecular identification for the pathogens norovirus, Salmonella spp., Campylobacter jejuni, Campylobacter coli, and Campylobacter lari, verocytotoxin-producing E. coli (particularly serovar O157:H7), Shigella spp., and Yersinia enterocolitica. In 5 communities, the presence of Giardia duodenalis and Cryptosporidium spp. was also tested by microscopy and molecular methods and that of Toxoplasma gondii was tested by molecular methods. Apart from small quantities of Clostridium perfringens in 2 samples, no bacterial or viral pathogens were detected in the mussels. Toxoplasma gondii was also not detected. However, G. duodenalis and Cryptosporidium spp. were present in 18% and 73% of the samples investigated for these pathogens, respectively. When considering the indicators and the viral and bacterial pathogens investigated, the mussels examined were of good microbiological quality, but considering the presence of potentially zoonotic protozoa, it should be recommended that consumers cook the molluscs well before eating them.

Prevalence and molecular characterization of Cryptosporidium spp. and Giardia duodenalis in diarrhoeic patients in the Qikiqtani Region, Nunavut, Canada

“…Dried intestines from ringed seals, for example, are commonly consumed, and these animals have been reported to be infected with both Cryptosporidium and Giardia ( 14 – 16 ). A few other northern marine mammals have also been reported as hosts for G. duodenalis or Cryptosporidium spp., including bearded seals and bowhead whales ( 16 , 17 ). There have been several reports of Giardia in terrestrial animals in northern Canada.…”

“…in terrestrial animals is, however, thought to be relatively low in the north, and Cryptosporidium oocysts have only been reported in caribou and dogs in these regions ( 10 ). Cryptosporidium and Giardia have also been reported in blue mussels harvested in the Nunavik region of Quebec ( 17 ).…”

“…To date, there is little information available on the species and genotypes of Cryptosporidium and Giardia in wildlife and domestic animals in the Canadian North. C. muris has been reported in ringed seals and blue mussels in Nunavik, Quebec ( 17 , 18 ). This is of some concern to public health as both are important traditional food items, and C. muris has been previously reported in humans in a number of countries ( 19 ).…”

Wastewater treatment and public health in Nunavut: a microbial risk assessment framework for the Canadian Arctic

“…A study of the microbial quality of blue mussels (Mytilus edulis) in six Inuit communities in Nunavik, Quebec (Canada) found the mussels examined to be of good microbiological and viral quality but did detect the presence of the potentially pathogenic protozoa Giardia duodenalis and Cryptosporidium spp. (Lévesque et al 2010).…”

“…Information about the levels of pathogens present in specific wildlife and fish is necessary to build accurate probability distributions for human exposure. With the exception of shellfish, there is a lack of data about the uptake, latency and transmission of wastewater pollution by animals that are common in the Inuit diet (Lévesque et al 2010). Studies and environmental monitoring of the microbiological quality of specific fish and animals that are favoured as a food source, are present near treatment areas, and may be vectors are recommended.…”