Salmonella contamination and hazard analysis in a storage facility for feed materials in Japan.

AIMS: To reduce Salmonella contamination of animal feeds, Salmonella contamination in a feed materials storage facility was investigated, and hazard analysis was performed to acquire the basic information necessary to establish a control method for Salmonella. The result is that managers of feed materials storage facilities will be able to introduce the Hazard Analysis and Critical Control Point (HACCP) systems to quickly and efficiently. METHODS AND RESULTS: A total of 472 samples, including deposits, adhesions, environment samples and materials, were investigated. The detection rate in the storage facility was 5.1% (24/472) over the three-year investigation period. The serovars of detected Salmonella were Agona, Anatum, Bron (or Agbeni), Chester, Infantis, Mbandaka, Minnesota, Muenster, Sinstorf, Typhimurium, O18:- and O1,3,19:-. As a result of hazard analysis after confirming the multiplication factors and detection rate, important hazards were judged to be the outdoor equipment and dust collector. CONCLUSIONS: The risk of Salmonella contamination in storage facilities was clarified. Important Salmonella hazards in storage facilities are Salmonella-contaminated feed materials, multiplication factors such as rainwater and dew condensation, and Salmonella-accumulated dust in dust collectors for fine-powder recovery. These results suggest that proper control of these hazards could reduce the risk of Salmonella in storage facilities. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report describing actual Salmonella contamination conditions and risk assessment using the hazard analysis at a feed materials storage facility in Japan. This study will consider implications for the feed industry because the hazard analysis clarified the sites of Salmonella contamination, the tendency of contamination and the points for implementing control measures in the feed materials storage facility.

Synthesis of nucleobase-caged peptide nucleic acids having improved photochemical properties.

A nucleobase-caged peptide nucleic acid (PNA) having a (6-bromo-7-methoxycoumarin)-4-ylmethoxycarbonyl (Bmcmoc) caging group was newly synthesized. The Bmcmoc-caged PNAs were photolyzed to produce parent PNAs with a high photochemical efficiency. Introduction of a single Bmcmoc group was sufficient to suppress polymerase chain reaction (PCR) clamping activity and triplex invasion complex formation. Photo-mediated restoration of the PCR clamping activity was also demonstrated.

Complete mineralization of propyzamide in aqueous solution containing TiO2 particles and H2O2 by the simultaneous irradiation of light and ultrasonic waves.

Environmental problems arise from the pollution of ground water and soil by propyzamide, 3,5-dichloro-N-(3-methyl-1-butyn-3-yl) benzamide, which is a popular herbicide. To decompose propyzamide, aqueous solutions containing propyzamide and TiO2 particles was irradiated by light. The photocatalytic decomposition was accelerated when the solution temperature and pH were high. The temperature dependence was due to the adsorption processes of propyzamide on the TiO2 particles. The decomposition was further promoted by addition of H2O2 because of its effective electron-trapping and generated *OH which was available to decompose propyzamide. Although no propyzamide was detected in the solution after the irradiation time of about 20 min, the decomposed intermediate compounds still remained. In order to mineralize completely propyzamide, simultaneous irradiation by light and ultrasonic waves was carried out. The hybrid effect of the irradiation by light and ultrasonic waves in conjunction with H2O2 was first confirmed to achieve the complete mineralization of propyzamide.