| evidence for a high rate of false-positive results with the indirect fluorescent antibody test for ehrlichia risticii antibody in horses. | the original objective was to determine seroprevalence of ehrlichia risticii antibody among horses in california. on the basis of the unexpected results of the survey, an investigation into the accuracy and reproducibility of results of the indirect fluorescent antibody (ifa) test for e risticii was carried out. | 1995 | 7493874 |
| detection of ehrlichia risticii, the agent of potomac horse fever, in freshwater stream snails (pleuroceridae: juga spp.) from northern california. | ehrlichia dna was identified by nested pcr in operculate snails (pleuroceridae: juga spp.) collected from stream water in a northern california pasture in which potomac horse fever (phf) is enzootic. sequencing of pcr-amplified dna from a suite of genes (the 16s rrna, groesl heat shock operon, 51-kda major antigen genes) indicated that the source organism closely resembled ehrlichia risticii, the causative agent of phf. the minimum percentage of juga spp. harboring the organism in the population ... | 1998 | 9687446 |
| 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 |
| detection of neorickettsia risticii from various freshwater snail species collected from a district irrigation canal in nevada county, california. | this study investigated the role of a district irrigation canal in nevada county, california, usa, as the point source of infection for neorickettsia risticii, causative agent of equine neorickettsiosis (en). a total of 568 freshwater snails comprising juga spp., planorbella subcrenata (carpenter, 1857) (rough rams-horn), physella virgata (gould, 1855) (protean physa) and feces from three horses with en were collected and tested for n. risticii by real-time pcr. a total of four freshwater snails ... | 2013 | 23566936 |