Experimental model for study bacteriophage bioaccumulation by a bivalve Unio pictorium (L.1758)

Abstract

Abstract The filter-feeding bivalves capture particles of small living organisms, including bacteria and single-cell eukaryotes, from their water environment. In the previous studies bioaccumulation of viruses by bivalve molluscs had been shown. Being cultivated in the environment polluted with waste waters, these filter-feeding aquatic organisms can accumulate microorganisms, including human pathogenic bacteria and viruses, and become a health risk factor causing outbreaks of various diseases, mainly the intestine infections. Bacteriophages may serve as a safe model for investigation of virus capture from environmental waters by mollusks; besides the investigations of phage bioaccumulation give insight into the natural mechanisms of the process. We developed a simplest experimental unit, microcosm, observing bacteriophages bioaccumulation by a freshwater bivalve Unio pictorium. The bioaccumulation process was tested with two T4 bacteriophage concentrations. The phage titer in the mollusk water environment first decreased due to its bioaccumulation and then essentially increased after the long incubation of the system. The results allowed us to suppose that the bacteriophage propagates in the E.coli population inhabiting the intestine tract of a mollusk taken from natural environment.