Inter-Laboratory Study to Validate New Rapid Screening Methods for Kudoa septempunctata.

Kudoa septempunctata is the causative agent of a food-borne disease associated with the ingestion of raw olive flounder. As the current qRT-PCR method for its detection is time-consuming, a rapid and simple method is required. Recently, a new real-time loop-mediated isothermal amplification (LAMP) method and an immunochromatography method, whose sensitivities are intended to be compatible with that designated in the official analytical method (10(5) spores/g olive flounder), have been developed.

Genetic variation of Listeria monocytogenes isolates from domestic and imported foods in Japan.

Phylogenetic analyses were carried out on a total of 118 Listeria monocytogenes isolates from foods or food processing environments, and 7 isolates from listeriosis patients in Japan to evaluate the genetic variation in the pathogen in this country. Isolates of serotypes 1/2a, 1/2b and 4b were mainly examined to assess the risk of exposure of humans to L. monocytogenes from foods in Japan.

Characteristics of Listeria monocytogenes isolated from imported meat in Japan.

The genomic structure of the iap region in Listeria monocytogenes (serovar 4b), isolated from chicken imported into Japan, was compared with those from Japanese strains. The isolate was similar to the Japanese strains in a comparatively new, rare group. Such strains might be imported from foreign countries.

Invasion assay of Listeria monocytogenes using Vero and Caco-2 cells.

The invasion ability of Listeria monocytogenes into cultured cells has been used to evaluate its pathogenicity. In this study, invasive ability was investigated using Vero and Caco-2 cell lines. The form of invasion showed no morphological differences between both cell lines inoculated with L.

Analysis of the molecular evolution of Listeria monocytogenes isolated from Japanese meats and environment.

Food contaminated by Listeria monocytogenes is a problem on a worldwide level because it is a serious food-borne pathogen. Although 3 evolutionary divisions have been reported for L. monocytogenes, the evolution of Japanese isolates has not yet been clarified.

Comparison of genomic structures in the serovar 1/2a Listeria monocytogenes isolated from meats and listeriosis patients in Japan.

Foodborne disease by Listeria monocytogenes, serovar 1/2a has recently been reported in many countries. Although contamination by this bacteria is also known to be gradually spreading among the marketed foods of Japan, there is little information on relation between listeriosis and food contamination. In the present study, the characteristics of the genomic structures of serovar 1/2a were compared among the isolates from marketed meats and listeriosis patients.