title: In situ detection of Anaplasma spp. by DNA target-primed rolling-circle amplification of a padlock probe and intracellular colocalization with immunofluorescently labeled host cell von Willebrand factor.
abstract: Endothelial cell culture and preliminary immunofluorescent staining of Anaplasma-infected tissues suggest that endothelial cells may be an in vivo nidus of mammalian infection. To investigate endothelial cells and other potentially cryptic sites of Anaplasma sp. infection in mammalian tissues, a sensitive and specific isothermal in situ technique to detect localized Anaplasma gene sequences by using rolling-circle amplification of circularizable, linear, oligonucleotide probes (padlock probes) was developed. Cytospin preparations of uninfected or Anaplasma-infected cell cultures were examined using this technique. Via fluorescence microscopy, the technique described here, and a combination of differential interference contrast microscopy and von Willebrand factor immunofluorescence, Anaplasma phagocytophilum and Anaplasma marginale were successfully localized in situ within intact cultured mammalian cells. This work represents the first application of this in situ method for the detection of a microorganism and forms the foundation for future applications of this technique to detect, localize, and analyze Anaplasma nucleotide sequences in the tissues of infected mammalian and arthropod hosts and in cell cultures.
authors.affiliation: Department of Infectious Diseases and Pathology, University of Florida, College of Veterinary Medicine, Gainesville, Florida 32610, USA. wamsleyh@vetmed.ufl.edu
authors.forename: Heather L
authors.initials: HL
authors.lastname: Wamsley
authors.forename: Anthony F
authors.initials: AF
authors.lastname: Barbet
mesh_terms: D042322:Anaplasma marginale / Q000235:genetics / Q000302:isolation & purification*; D041081:Anaplasma phagocytophilum / Q000235:genetics / Q000302:isolation & purification*; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D042783:Endothelial Cells / Q000382:microbiology; D005455:Fluorescent Antibody Technique; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods*; D008253:Macaca mulatta; D008856:Microscopy, Fluorescence; D008857:Microscopy, Interference; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D014841:von Willebrand Factor / Q000032:analysis*
chemical_list: D017931:DNA Primers; D014841:von Willebrand Factor