title: Effect of Rickettsia felis Strain Variation on Infection, Transmission, and Fitness in the Cat Flea (Siphonaptera: Pulicidae).
abstract: Rickettsia felis is a human pathogen transmitted by the cat flea, Ctenocephalides felis (Bouché) (str. LSU), as well as an obligate symbiont of the parthenogenic booklouse Liposcelis bostrychophila (Badonnel) (str. LSU-Lb). The influence of genetic variability in these two strains of R. felis on host specialization and fitness and possible resulting differences on infection and transmission kinetics in C. felis is unknown. Utilizing an artificial host system, cat fleas were exposed to a R. felis str. LSU-Lb-infected bloodmeal and monitored for infection at 7-d intervals for 28 d. Quantitative real-time PCR was used to determine rickettsial load and infection density in newly exposed cat fleas, and transmission frequency between cat fleas. The effect of persistent R. felis infection on cat flea F1 progeny was also assessed. At 7 d postexposure 76.7% of the cat fleas successfully acquired R. felis str. LSU-Lb. In R. felis str. LSU-Lb-exposed cat fleas, the mean infection load (6.15 × 106), infection density (0.76), and infection prevalence (91/114) were significantly greater than R. felis str. LSU infection load (3.09 × 106), infection density (0.68), and infection prevalence (76/113). A persistent R. felis str. LSU-Lb infection was detected for 28 d in adult cat fleas but neither female:male ratio distortion nor vertical transmission was observed in F1 progeny. While infection kinetics differed, with higher intensity associated with R. felis str. LSU-Lb, no distinct phenotype was observed in the F1 progeny.
authors.affiliation: Department of Pathobiological Sciences, Louisiana State University School of Veterinary Medicine, Vector-Borne Disease Laboratories, Baton Rouge, LA 70803.|Department of Entomology, Louisiana State University, Baton Rouge, LA 70803.
authors.forename: Sean P
authors.initials: SP
authors.lastname: Healy
authors.affiliation: Department of Pathobiological Sciences, Louisiana State University School of Veterinary Medicine, Vector-Borne Disease Laboratories, Baton Rouge, LA 70803.|Department of Biological Science, Vanderbilt University, Nashville, TN 37235.
authors.forename: Lisa D
authors.initials: LD
authors.lastname: Brown
authors.affiliation: Department of Pathobiological Sciences, Louisiana State University School of Veterinary Medicine, Vector-Borne Disease Laboratories, Baton Rouge, LA 70803.|Iowa State University, College of Veterinary Medicine, Ames, IA 50011.
authors.forename: Melena R
authors.initials: MR
authors.lastname: Hagstrom
authors.affiliation: Department of Entomology, Louisiana State University, Baton Rouge, LA 70803.
authors.forename: Lane D
authors.initials: LD
authors.lastname: Foil
authors.affiliation: Department of Pathobiological Sciences, Louisiana State University School of Veterinary Medicine, Vector-Borne Disease Laboratories, Baton Rouge, LA 70803.
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Macaluso
mesh_terms: D000818:Animals; D058491:Bacterial Load; D002371:Cat Diseases / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission*; D002415:Cats; D005260:Female; D056084:Genetic Fitness; D058507:Host Specificity; D018445:Infectious Disease Transmission, Vertical / Q000662:veterinary*; D008297:Male; D015995:Prevalence; D012282:Rickettsia Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission / Q000662:veterinary*; D041161:Rickettsia felis / Q000235:genetics / Q000502:physiology*; D005423:Siphonaptera / Q000382:microbiology* / Q000502:physiology*
keywords: Ctenocephalides felis; Liposcelis bostrychophila; Rickettsia felis strain; cat flea; infection kinetics