title: In vitro isolation and infection intensity of Rickettsia parkeri in Amblyomma triste ticks from the Paraná River Delta region, Argentina.
abstract: In the present study, we report the first in vitro isolation and infection intensity of Rickettsia parkeri in Amblyomma triste ticks from Argentina. No genetic differences in the molecular targets evaluated were found between R. parkeri isolates from Argentina and those R. parkeri isolates reported in Uruguay and Brazil, both obtained from A. triste. Only a minor difference was observed when compared to R. parkeri isolated from Amblyomma maculatum from United States. Moreover, the prevalence of infection by R. parkeri in ticks collected from the vegetation in the Paraná Delta was high (20.4%). Interestingly, the distribution of R. parkeri infection intensity observed in A. triste ticks was distinctly bimodal, with approximately 60% of the infected ticks presenting high rickettsial loads (3.8×10(5)-4.5×10(7) ompA copies/tick) and the remainder with low rickettsial levels (5.6×10(1)-6.5×10(3) ompA copies/tick). This bimodality in R. parkeri infection intensity in ticks could determine differences in the severity of the disease, but also be important for the infection dynamics of this pathogen. Further research exploring the distribution of rickettsial infection levels in ticks, as well as its determinants and implications, is warranted.
authors.affiliation: Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral, Universidad Nacional del Litoral - Consejo Nacional de Investigaciones Científicas y Técnicas, Esperanza, Argentina. Electronic address: lmonje@fcv.unl.edu.ar.
authors.forename: Lucas D
authors.initials: LD
authors.lastname: Monje
authors.affiliation: Instituto Nacional de Tecnología Agropecuaria, E.E.A. Rafaela, Rafaela, Argentina.
authors.forename: Santiago
authors.initials: S
authors.lastname: Nava
authors.affiliation: Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral, Universidad Nacional del Litoral - Consejo Nacional de Investigaciones Científicas y Técnicas, Esperanza, Argentina.
authors.forename: Leandro R
authors.initials: LR
authors.lastname: Antoniazzi
authors.affiliation: Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral, Universidad Nacional del Litoral - Consejo Nacional de Investigaciones Científicas y Técnicas, Esperanza, Argentina.
authors.forename: Valeria C
authors.initials: VC
authors.lastname: Colombo
authors.affiliation: Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral, Universidad Nacional del Litoral - Consejo Nacional de Investigaciones Científicas y Técnicas, Esperanza, Argentina.
authors.forename: Pablo M
authors.initials: PM
authors.lastname: Beldomenico
mesh_terms: D000818:Animals; D001096:Arachnid Vectors / Q000382:microbiology*; D001118:Argentina / Q000453:epidemiology; D001483:Base Sequence; D002522:Chlorocebus aethiops; D004269:DNA, Bacterial / Q000235:genetics; D005260:Female; D006801:Humans; D026863:Ixodidae / Q000382:microbiology*; D008297:Male; D008969:Molecular Sequence Data; D012281:Rickettsia / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D012282:Rickettsia Infections / Q000453:epidemiology* / Q000382:microbiology; D017422:Sequence Analysis, DNA; D014709:Vero Cells
chemical_list: D004269:DNA, Bacterial
keywords: Amblyomma triste; Argentina; Infection intensity; Isolation; Rickettsia parkeri