Behavior of Escherichia coli and male-specific bacteriophage in environmentally contaminated bivalve molluscs before and after depuration

• Published in: Applied and Environmental Microbiology 1995-08, Vol.61 (8), p.2830-2834
• Main Authors: Dore, W.J. (Ministry of Agriculture, Fisheries and Food, Weymouth, Dorset, England.), Lees, D.N
• Format: Article
• Language: English
• Subjects: AGUAS FECALES; Animal, plant and microbial ecology; Animals; APPAREIL DIGESTIF; Applied ecology; Bacteria; BACTERIOFAGOS; BACTERIOPHAGE; BIODEGRADACION; BIODEGRADATION; Biological and medical sciences; Biology; Bivalvia - microbiology; Bivalvia - virology; Coliphages - isolation & purification; CRASSOSTREA GIGAS; DESINTOXICACION; DETOXIFICATION; Digestive System - microbiology; Digestive System - virology; EAU USEE DOMESTIQUE; Ecotoxicology, biological effects of pollution; Effluents; Environment; ESCHERICHIA COLI; Escherichia coli - isolation & purification; ESPECE; ESPECIES; Fundamental and applied biological sciences. Psychology; INFECCION; INFECTION; INTESTIN; INTESTINOS; Marine; Marine and brackish environment; Microbiology; Miscellaneous; MYTILUS EDULIS; Organ Specificity; ORGANISME INDICATEUR; ORGANISMOS INDICADORES; Ostreidae - microbiology; Ostreidae - virology; Public health; RADIACION ULTRAVIOLETA; RAYONNEMENT ULTRAVIOLET; Sewage; Shellfish; Shellfish - microbiology; Shellfish - virology; SISTEMA DIGESTIVO; Viruses; Water Microbiology
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/aem.61.8.2830-2834.1995

We monitored the differential reduction rates and elimination patterns of Escherichia coli and male-specific (F+) bacteriophage during UV depuration for 48 h in oysters (Crassostrea gigas) and mussels (Mytilus edulis) contaminated by short-term (1 to 3 weeks) and long-term (more than 6 months) exposure to sewage in the marine environment. The time taken to reduce levels of E. coli by 90% was 6.5 h or less in all cases. In contrast, the amounts of time needed to reduce levels of F+ bacteriophage by 90% were considerably longer: 47.3 and 41.3 h (after short- and long-term exposures, respectively) in mussels and 54.6 and 60.8 h (after short- and long-term exposures, respectively) in oysters. No differences in the rates of reduction of indicators of viral pollution following exposure of the shellfish to either short- or long-term sewage contamination were observed. Further experiments were conducted with mussels to determine the relative distributions of E. coli and F+ bacteriophage in tissue before and during depuration. Prior to depuration the majority of E. coli organisms (90.1%) and F+ bacteriophage (87.3%) were detected in the digestive tract (i.e., the digestive gland and intestine). E. coli and F+ bacteriophage were reduced in all tissues except the digestive gland to undetectable levels following depuration for 48 h. Within the digestive gland, levels of F+ bacteriophage were reduced to 30% of initial levels, whereas E. coli was reduced to undetectable levels. These results confirm previous laboratory studies showing the differential reductions of levels of E. coli and F+ bacteriophage during depuration. They also demonstrate that these differential elimination patterns are not affected by the duration of sewage contamination and that F+ bacteriophage are retained only in the digestive gland and are not sequestered into other internal tissues