[Detection methods of enterohemorrhagic Escherichia coli O111 in beef: a collaborative study].

To establish a detection method for enterohemorrhagic Escherichia coli (EHEC) O111 in meat, a single-laboratory evaluation and a collaborative study were conducted focusing on comparisons of the efficiencies in combination with enrichment, a direct plating method and a plating method with immunomagnetic separation (IMS-plating method) using various agar media for EHEC O111, loop-mediated isothermal amplification (LAMP) assay targeting the Verocytotoxin (VT) gene as a molecular detection method. On a single-laboratory evaluation, enrichment in modified EC at 36 degrees C was inferior to that in modified EC supplemented with novobiocin (NmEC) and mEC at 42 degrees C to isolate EHEC O111 by plating methods. On a collaborative study, there were no significant differences between combinations of enrichment in NmEC at 42 degrees C-LAMP assay and enrichment in mEC at 42 degrees C-LAMP assay.

[Application of one step RT-PCR assay for detection of flavivirus RNA in mosquitoes].

The conditions of one step RT-PCR method for detection of virus RNA in field-collected mosquitoes, and preservation period of infected mosquitoes for one step RT-PCR were examined. We compared several virus RNA extraction methods with artificially contaminated mosquito pools with dengue virus (DV), Japanese encephalitis virus (JEV), and yellow fever virus (YFV) with a known amount of plaque forming unit (PFU) to establish the condition of one step RT-PCR. In this study, most effective RNA extraction method was ISOGEN-LS extraction combined with supernatant of centrifuged mosquito homogenates.

[Antibody responses in Japanese volunteers after immunization with yellow fever vaccine].

To monitor the development of specific and cross-reactive antibody response in twenty Japanese volunteers after vaccination with live yellow fever vaccine. Serum samples were collected on various days after vaccination and examined for hemagglutination inhibition (HI) antibodies against yellow fever virus (YFV), Japanese encephalitis virus (JEV) and dengue virus (DV), neutralizing antibodies against YFV and JEV, and IgM antibodies against YFV. None of the volunteers had been previously immunized with this vaccine.