title: Distribution of spotted fever group rickettsiae in select tissues of experimentally infected and field-collected Gulf Coast ticks.
abstract: Salivary glands, midgut, Malpighian tubules, and ovaries were dissected from infected, colony-derived Amblyomma maculatum (Gulf Coast ticks) injected as nymphs with either Rickettsia parkeri (a spotted fever group rickettsia [SFGR]; treatment) or phosphate-buffered saline (negative control). For comparison, similar tissues were dissected from hemolymph-positive, field-collected ticks. Tissues were analyzed by indirect fluorescent antibody (IFA) tests. All phosphate-buffered saline-injected ticks were IFA negative, whereas SFGR were detected by IFA in 100% of the salivary glands and ovaries and 78 and 75% of midgut and Malpighian tubule samples, respectively, of R. parkeri-injected ticks. Nearly 22% (10/46) of the field-collected ticks were hemolymph positive. Of those, SFGR were detected by IFA in 80% of the salivary glands, 67% of the ovaries, and 60% in the midgut and Malpighian tubules. This is the first study to assess the distribution of SFGR in select tissues of A. maculatum ticks.
authors.affiliation: Department of Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA. kt20@msstate.edu
authors.forename: Kristine T
authors.initials: KT
authors.lastname: Edwards
authors.forename: Jerome
authors.initials: J
authors.lastname: Goddard
authors.forename: Andrea
authors.initials: A
authors.lastname: Varela-Stokes
mesh_terms: D000818:Animals; D001096:Arachnid Vectors / Q000382:microbiology*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D041981:Gastrointestinal Tract / Q000382:microbiology; D026863:Ixodidae / Q000382:microbiology*; D008297:Male; D008922:Mississippi; D010053:Ovary / Q000382:microbiology; D016133:Polymerase Chain Reaction; D012281:Rickettsia / Q000235:genetics / Q000302:isolation & purification*