Scallop shell powder produced by calcination process − the average diameter of the powder particles being 20 µm (SSP) − was further ground into nano-sized particles, with average diameter of 500 nm, here designated CaO-Nano. Solution of CaO-Nano could inactivate avian influenza virus within 5 sec, whereas the solution of SSP could not even after 1 hr incubation. CaO-Nano solution could also inactivate Newcastle disease virus and goose parvovirus within 5 sec and 30 sec, respectively. The virus-inactivating capacity (neutralizing index: NI>3) of the solution was not reduced by the presence of 20% fetal bovine serum. CaO-Nano solution seems to be a good candidate of materials for enhancement of biosecurity in farms.

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Background. This study investigates the viable persistence of avian influenza viruses (AIVs) in various types of artificially frozen environmental water and evaluates the feasibility of similar occurrence taking place in nature, and allowing for prolonged abiotic virus survival, with subsequent biotic viral recirculation. Methods. Fresh, brackish, and salty water, taken in Japan from aquatic biotopes regularly visited by migratory waterfowl, were seeded with AIVs. We monthly monitored the viability of the seeded viruses in the frozen state at −20°C and −30°C, for 12 months. We also monitored virus viability following repeatedly induced freezing and thawing. Results. The viruses exhibited considerable viable persistence all along that period of time, as well as during freezing-thawing cycles. Appreciable, yet noncrucial variances were observed in relation to some of the parameters examined. Conclusions. As typical waterborne pathogens of numerous northerly aquatic birds, AIVs are innately adapted to both the body temperature of their hosts (40°C to 42°C) and, presumably, to subzero temperatures of frozen lakes (down to −54°C in parts of Siberia) occupied and virus-seeded by subclinically infected birds, prior to freezing. Marked cryostability of AIVs appears to be evident. Preservation in environmental ice has significant ecophylogenetic and epidemiological implications, potentially, and could account for various unexplained phenomena.

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An acidic agent, potassium monopersulfate (PMPS), was evaluated for bactericidal and virucidal effects against Salmonella Infantis (SI), Escherichia coli, rifampicin-resistant Salmonella Infantis (SI-rif), Newcastle disease virus (NDV), and avian influenza virus (AIV), in the absence or presence of organic materials. In addition, inactivation activity toward a virus on virus-spiked clothes was also examined. PMPS could inactivate SI, E. coli, and SI-rif even in the presence of organic materials under various concentrations and exposure/contact time conditions. PMPS could also inactivate NDV and AIV. In addition, PMPS could inactivate AIV on a virus-spiked rayon sheet. In conclusion, the present study showed that PMPS has good antimicrobial properties against SI, E. coli, SI-rif, NDV, and AIV when used at the optimal dosage and exposure timing. These results suggest that PMPS could be used as an alternative disinfectant for biosecurity enhancement in animal farms or hospitals.