Kazutoshi Takami

Molecular characterization of crane Coccidia, Eimeria gruis and E. reichenowi, found in feces of migratory cranes

Eimeria gruis and E. reichenowi have lethal pathogenicity to a number of species of cranes. These parasites develop at multiple organs or tissues in infected cranes, thus lacking the specificity of infection sites shown by other Eimeria spp. in spite of morphologic similarity. To date, there have been many reports of crane Eimeria infections, however, genetic examinations of these parasites have never been published. In the present study, we isolated oocysts of E. gruis and E. reichenowi from crane feces at a wintering area in Japan. By phylogenic analysis, we first demonstrated that partial sequences of the isolates formed their own cluster, located separately from other Eimeria spp.

SURVEY OF CRYPTOSPORIDIUM SPP. AND GIARDIA SPP. INFECTIONS IN VARIOUS ANIMALS AT A ZOO IN JAPAN

Abstract A total of 284 fecal samples of 89 species (43 mammalian species and 46 avian species) were examined for Cryptosporidium oocysts and Giardia cysts from 1999 to 2002. Each sample was collected at the zoo located at Osaka in Japan and examined by microscopy after performing the sucrose flotation method and by two immunofluorescent assay kits for detection of Cryptosporidium oocysts and Giardia cysts. Cryptosporidium spp. was found only in a raccoon dog (Nyctereutes procyonoides), and Giardia spp. was detected in a mandarin duck (Aix galericulata) and two ruddy shelducks (Tadorna ferruginea). In this study, the prevalences of these parasites were found to be low. However, these results suggested that the infected animals could serve as a source of contamination for surface water. This is the first report about the survey of Cryptosporidium spp. and Giardia spp. at a zoo in Japan.

Molecular Characterization of a Cryptosporidium Isolate From a Banded Mongoose Mungos mungo

Cryptosporidium spp. has been found in more than 150 species of mammals, but there has been no report in mongooses. In this study, we report the isolation of Cryptosporidium sp. in a banded mongoose Mungos mungo, which was brought from Tanzania to Japan; the isolate was analyzed genetically to validate the occurrence of a new, host-adapted genotype. Cryptosporidium diagnostic fragments of 18S ribosomal RNA and 70-kDa heat shock protein genes were amplified from this isolate and compared with the other Cryptosporidium species and genotypes reported previously. Analyses showed that the mongoose isolate represents a new genotype, closely related to that of bears.

Molecular phylogeny of Blastocystis isolates from wild rodents captured in Indonesia and Japan

Blastocystis sp. is a common intestinal protist found worldwide in a variety of animals, including humans. Currently, 17 subtypes (STs) of Blastocystis isolates from mammalian and avian host species have been reported based on the small subunit ribosomal RNA gene (SSU rDNA). Among these, human Blastocystis were only identified among STs 1–9. Except ST9, all other STs comprised isolates from humans and other animal species. Entire sequence data of the SSU rDNA of nine Blastocystis isolates from laboratory rats or guinea pigs previously showed ST4, whereas Blastocystis isolates from wild rodents have not been addressed genetically. In this study, Blastocystis infection in wild rodents was surveyed in Indonesia and Japan, and 11 and 12 rodent Blastocystis parasites were obtained from Rattus exulans and R. novercious, respectively. All new Blastocystis isolates from wild rodents were identified as ST4 based on the SSU rDNA sequences. The best tree inferred with the entire sequences of the SSU rDNA of all ST4 isolates including 17 data registered in GenBank clearly showed monophyletic ST4A and ST4B clades. Although ST4 isolates from laboratory rats were separated into these two clades, all Blastocystis isolates from wild rodents in the present study were positioned into the clade ST4A and further separated into two sub-clusters within the clade ST4A according to the location of the host species. Considering the fact that laboratory rats were susceptible to both ST4A and ST4B, separation of the monophyletic sub-clusters of Blastocystis isolates from Indonesian Polynesian rats and Japanese brown rats may indicate the presence of geographical variations rather than a host-specific separation. In either way, the robust host preference to rodent species of ST4 Blastocystis was also confirmed.

Evidence of infection with Leptospira interrogans and spotted fever group rickettsiae among rodents in an urban area of Osaka City, Japan

We examined 33 rodents captured in an urban area of Osaka City, Japan for IgG antibodies against Seoul virus, severe fever with thrombocytopenia syndrome virus, hepatitis E virus, Leptospira interrogans, Yersinia pestis, spotted fever, typhus and scrub typhus group rickettsiae. We found that 3 (9.1%) and 1 (3.0%) of the 33 rodents had antibodies against L. interrogans and spotted fever group rickettsiae, respectively. DNAs of leptospires were detected from 2 of the 3 seropositive rodents, but DNA of rickettsia was not detected. Phylogenetic analysis and multiple locus sequence typing revealed that the 2 leptospires were L. interrogans belonging to a novel sequence type. There is a potential risk for acquiring rodent-borne zoonotic pathogens even in cities in developed countries.