Antiviral activity of antibiotic-producing marine bacteria

Abstract

The stability of poliovirus 1 in estuarine water and sediment was examined. A 2 log reduction in virus titer at 15.degree. C occurred within 6-7 days in water samples taken from estuarine waters on both sides of the Atlantic Ocean. The antiviral effect decreased significantly when the seawater was subjected to autoclaving but not when it was filtered. That the antiviral activity of the seawater was related to the growth activities of microorganisms was corroborated by the isolation of antibiotic-producing marine bacteria that had marked activity against poliovirus (net inactivation .gtoreq. 2 log within 6-8 days). These organisms retained this activity following repeated subcultivation on laboratory media. Since comparable inactivation rates were observed in cell-free filtrates from these marine strains, extracellular products appear to be involved in the virus-inactivation process. Other enteric viruses, coxsackie B-5 and echo-6, were also inactivated by these marine bacteria. The addition of sediment to natural seawater increased the length of poliovirus survival > 3 times over that in seawater alone. This was not found under sterile conditions, suggesting that the sediment can protect the viruses from inactivation by the marine microflora.