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Biomedical subjects

Yasukazu Muramatsu

Publications and source records attributed to Yasukazu Muramatsu.

8 recordsLinked to original sources
PubMed2006

Seroepidemiologic survey of Coxiella burnetii and attempt to detect Coxiella DNA in aged non-laying chickens in a prefecture of Japan where poultry farming prospers.

The indirect fluorescent antibody test (IFAT) revealed seropositivity to Coxiella burnetii in aged non-laying chickens in poultry farms in a prefecture in the central part of Japan. Seropositivity was 7%, and antibody titers ranged from 16 to 64. No DNA fragment specific for C. burnetii was detected in the chickens by nested-PCR. The prevalence of C. burnetii infection in a prefecture of Japan in which poultry farming prospers was 7%.

Agriculture↗
PubMed2005

Detection of ehrlichial DNA in small rodents captured in a woodland area of Hokkaido, the northernmost island of Japan, where Lyme disease is endemic.

The ehrlichial gene was detected in small rodents trapped in a Lyme disease-endemic area in Hokkaido, the northernmost island of Japan. Primer pairs of 16S rDNA targeting the genus Ehrlichia and other regions of the 16S rDNA specific for E. chaffeensis and E. muris were used for identification. The DNA fragment specific for 16S rDNA of Ehrlichia spp. was detected in 4 of 94 Apodemus speciosus mice (positive rate: 4.3%) and 5 of 73 Clethrionomys rufocanus bedfordiae mice (positive rate: 6.8%). The nucleotide sequence of the amplified 16S rDNA fragment was most similar to those of E. muris-like Ehrlichia, Ehrlichia spp. HF565 and Shizuoka-36, originating in the northern and central parts of Japan. In phylogenetic analysis based on 16S rDNA sequences, the northern, central and western groups of E. muris-like Ehrlichia from a cluster with microorganisms of the E. muris group. These results suggest that there are a group of E. muris microorganisms and a group of E. muris- like microorganisms in Japan.

Anaplasma↗
PubMed2004

Spotted fever group rickettsiae from ticks captured in Sudan.

Ticks were collected from ruminants in various areas of Sudan in 1998 and 2000. Primer pairs of rickettsial citrate synthase gene (gltA) and a spotted fever group (SFG) rickettsial 190-kDa surface antigen gene (rompA), respectively, were used for identification. Polymerase chain reaction (PCR)-positive products were used for DNA sequencing. The gltA gene was detected in 55% of the ticks examined (57/104). Among the 57 ticks studied, 19 were positive for the rompA gene. Thus, 18% of the ticks examined were found to be infected with SFG rickettsiae. The nucleotide sequences of the amplified rompA gene fragment of Hyalomma spp. and Amblyomma spp. were similar to those of Rickettsia aeschlimannii and Rickettsia africae, respectively. In this study, we succeeded in detecting the SFG rickettsiae gene in ticks, and established that there were at least two species of SFG rickettsiae in field ticks in Sudan.

Animals↗
PubMed2003

Detection of antibodies against spotted fever group Rickettsia (SFGR), typhus group Rickettsia (TGR), and Coxiella burnetii in human febrile patients in the Philippines.

A total of 157 sera from febrile patients in the Philippine General Hospital in Manila, Luzon, and the Northern Samar Provincial Hospital, the Philippines, were used. Serum antibodies against spotted fever group Rickettsia (SFGR) and typhus group Rickettsia (TGR) were detected by indirect immunofluorescence test. Antibody positive rates were 1.3% for SFGR (Rickettsia japonica) and 2.5% for TGR (R. typhus), respectively. Rickettsial antibodies in humans in the Philippines were found for the first time. These results underscore the need for further epidemiological study of clinical rickettsioses in the Philippines.

Antibodies, Bacterial↗
PubMed2002

Characterization of spotted fever group rickettsiae detected in dogs and ticks in Okinawa, Japan.

Spotted fever group (SFG) rickettsial DNAs were detected in 2.4% of 340 canine blood samples and a pool of 84 tick pool samples (229 ticks) collected in Okinawa, Japan by PCR using a citrate synthase and an SFG rickettsial 190-kDa surface antigen gene primer pair. The sequences of both genes from canine blood and tick samples showed high levels of similarity with those of Rickettsiajaponica and several SFG rickettsiae (R. aeschlimannii, R. massiliae, R. rhipicephali and Bar-29 strain). Phylogenesis of canine blood and tick samples was closely related to that of reference SFG rickettsiae. Serological evidence of SFG rickettsial infection in dogs and humans in Okinawa, where no clinical human cases have been reported, has been obtained. In this study, genetical characterization of SFG rickettsia in Okinawa was investigated phylogenetically.

Animals↗
PubMed2002

Molecular analysis of Neorickettsia risticii in adult aquatic insects in Pennsylvania, in horses infected by ingestion of insects, and isolated in cell culture.

Upon ingestion of adult aquatic insects, horses developed clinical signs of Potomac horse fever, and Neorickettsia risticii was isolated from the blood. 16S rRNA and 51-kDa antigen gene sequences from blood, isolates, and caddis flies fed to the horses were identical, proving oral transmission of N. risticii from caddis flies to horses.

Animals↗