Differential depuration of poliovirus, Escherichia coli, and a coliphage by the common mussel, Mytilus edulis

Abstract

The elimination of sewage effluent-associated poliovirus, Escherichia coli, and a 22-nm icosahedral coliphage by the common mussel, Mytilus edulis, was studied. Both laboratoryand commercial-scale recirculating, UV depuration systems were used in this study. In the laboratory system, the logarithms of the poliovirus, E. coli, and coliphage levels were reduced by 1.86, 2.9, and 2.16, respectively, within 52 h of depuration. The relative patterns and rates of elimination of the three organisms suggest that they are eliminated from mussels by different mechanisms during depuration under suitable conditions. Poliovirus was not included in experiments undertaken in the commercial-scale depuration system. The differences in the relative rates and patterns of elimination were maintained for E. coli and coliphage in this system, with the logarithm of the E. coli levels being reduced by 3.18 and the logarithm of the coliphage levels being reduced by 0.87. The results from both depuration systems suggest that E. coli is an inappropriate indicator of the efficiency of virus elimination during depuration. The coliphage used appears to be a more representative indicator. Depuration under stressful conditions appeared to have a negligible affect on poliovirus and coliphage elimination rates from mussels. However, the rate and pattern of E. coli elimination were dramatically affected by these conditions. Therefore, monitoring E. coli counts might prove useful in ensuring that mussels are functioning well during depuration.

Are fecal stanols suitable to record and identify a pulse of human fecal contamination in short-term exposed shellfish? A microcosm study

“…These results are in agreement with those of Selegean et al (2001) who conducted a similar experiment but on freshwater mussels contaminated by a WWTP effluent. Moreover, these results suggest that under these experimental conditions, the depuration process leading to the elimination of E. coli by defecation and lysozomal digestion of microorganisms (McHenery et al, 1979;Power and Collins, 1989;Love et al, 2010) from oyster tissues is not yet finished after 2 weeks. This depuration time is longer than those observed in depuration experiments in which fecally-contaminated oysters were allowed to depurate from E. coli in non-contaminated seawater (Buisson et al, 1981;Doré and Lees, 1995;Selegean et al, 2001;Pommepuy et al, 2003;Love et al, 2010), while in our experiment, oysters remained in fecally-contaminated water until ca.…”

Inactivation and elimination of human enteric viruses by Pacific oysters

“…the simultaneous depuration of HAV and PV from mussels, Mytilus chilensis ) have shown that different viruses are eliminated at distinct rates (Sobsey et al. 1987; Power and Collins 1989; Enriquez et al. 1992; Schwab et al.…”

Viral contaminants of molluscan shellfish: detection and characterisation

“…FRNA phages in particular have been described as promising candidates to evaluate the virological quality of shellfish (Lees, 2000). Several studies have shown a correlation between the elimination kinetics of F+ RNA phages and those of enteric viruses (Dore and Lees, 1995;Power and Collins, 1989;Power and Collins, 1990). Nevertheless reports on discrepancies in the occurrences of FRNA phages and pathogenic viruses are frequent.…”