| helminthic transmission and isolation of ehrlichia risticii, the causative agent of potomac horse fever, by using trematode stages from freshwater stream snails. | we report successful helminthic transmission of ehrlichia risticii, the causative agent of potomac horse fever, using trematode stages collected from juga yrekaensis snails. the ehrlichial agent was isolated from the blood of experimentally infected horses by culture in murine monocytic cells and identified as e. risticii ultrastructurally and by characterization of three different genes. | 2000 | 10699046 |
| infection rate of ehrlichia risticii, the agent of potomac horse fever, in freshwater stream snails (juga yrekaensis) from northern california. | juga yrekaensis freshwater snails were tested for trematode stages and for ehrlichia risticii dna using a nested pcr assay. snails were collected monthly from two potomac horse fever (phf) endemic locations in northern california (montague and weed). the trematode infection rate varied between 40 and 93.3% in large snails (shell size >15mm) and between 0 and 13.3% in small snails (<15mm). the highest trematode infection rate for large and small snails was recorded in september and the lowest inf ... | 2000 | 10946138 |
| detection of neorickettsia (ehrlichia) risticii in tissues of mice experimentally infected with cercariae of trematodes by in situ hybridization. | neorickettsia (ehrlichia) risticii was demonstrated to occur in cercariae developing in juga yrekaensis snails by experimental transmission, genetic detection and histopathology. cercariae were isolated from the digestive glands of snails collected in a fresh stream water area of siskiyou county, ca, and inoculated into cf1 mice. mice developed clinical signs, splenomegaly and histopathologic abnormalities. the agent was maintained by serial passages of whole blood in cf1 mice. a 527-bp product ... | 2002 | 12151198 |
| prevalence and sequence analyses of neorickettsia risticii. | the presence of neorickettsia (ehrlichia) risticii dna was confirmed by pcr amplification and sequence analysis from cercaria in snails collected from stream water in chungcheong and jeonra provinces. a total of 3,219 snails were tested for trematode cercariae and n. risticii infection. n. risticii 16s rrna gene fragment was amplified in cercariae from semisulcospira libertina and radix auricularia coreana snails by nested pcr. more than four genus cercariae (schistosomatidae, microphallidae, fu ... | 2003 | 12860635 |