ArticlePloS one2015
Amblyomma maculatum Feeding Augments Rickettsia parkeri Infection in a Rhesus Macaque Model: A Pilot Study.
Article in PloS one, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 26 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Who cites it
26 citing papers in PubMed, 33 citations in OpenAlex.
- Spotted fever group Rickettsia infection kinetics and cutaneous host response during single tick feeding events.PLoS pathogens · 2026Article
- Innate immune responses to Rickettsia: emerging themes and contrasts between species.Current opinion in microbiology · 2026Review
- Differences between human and rodent nitric oxide production dictate susceptibility to tick-bornebioRxiv : the preprint server for biology · 2025Article
- A conserved interaction between the effector Sca4 and host clathrin suggests additional contributions for Sca4 during rickettsial infection.Infection and immunity · 2024Article
- Critical roles ofInfection and immunity · 2024Article
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- Review
- Spotted Fever GroupMicrobiology spectrum · 2021Article
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- Establishment of a Rhesus Macaque Model for Scrub Typhus Transmission: Pilot Study to Evaluate the MinimalPathogens (Basel, Switzerland) · 2021Article
- Recent advances in understanding tick and rickettsiae interactions.Parasite immunology · 2021Review
- The enigmatic biology of rickettsiae: recent advances, open questions and outlook.Pathogens and disease · 2021Review
- Article
- Spotted Fever GroupInfection and immunity · 2019Article
- Amblyomma maculatum-associated rickettsiae in vector tissues and vertebrate hosts during tick feeding.Experimental & applied acarology · 2019Article
- A Pathogen and a Non-pathogen Spotted Fever GroupFrontiers in cellular and infection microbiology · 2019Article
- Macrophages Infected by a Pathogen and a Non-pathogen Spotted Fever GroupFrontiers in cellular and infection microbiology · 2019Article
- Article
- Vector Tick Transmission Model of Spotted Fever Rickettsiosis.The American journal of pathology · 2019Article
- Role of Sca2 and RickA in the Dissemination of Rickettsia parkeri in Amblyomma maculatum.Infection and immunity · 2018Article
Corrections and comments
- Erratum issued
Authors and funding
6 authors at 2 institutions in 1 country.
Funding
Abstract
Rickettsia parkeri is an emerging eschar-causing human pathogen in the spotted fever group of Rickettsia and is transmitted by the Gulf coast tick, Amblyomma maculatum. Tick saliva has been shown to alter both the cellular and humoral components of the innate and adaptive immune systems. However, the effect of this immunomodulation on Rickettsia transmission and pathology in an immunocompetent vertebrate host has not been fully examined. We hypothesize that, by modifying the host immune response, tick feeding enhances infection and pathology of pathogenic spotted fever group Rickettsia sp. In order to assess this interaction in vivo, a pilot study was conducted using five rhesus macaques that were divided into three groups. One group was intradermally inoculated with low passage R. parkeri (Portsmouth strain) alone (n = 2) and another group was inoculated during infestation by adult, R. parkeri-free A. maculatum (n = 2). The final macaque was infested with ticks alone (tick feeding control group). Blood, lymph node and skin biopsies were collected at several time points post-inoculation/infestation to assess pathology and quantify rickettsial DNA. As opposed to the tick-only animal, all Rickettsia-inoculated macaques developed inflammatory leukograms, elevated C-reactive protein concentrations, and elevated TH1 (interferon-γ, interleukin-15) and acute phase inflammatory cytokines (interleukin-6) post-inoculation, with greater neutrophilia and interleukin-6 concentrations in the tick plus R. parkeri group. While eschars formed at all R. parkeri inoculation sites, larger and slower healing eschars were observed in the tick feeding plus R. parkeri group. Furthermore, dissemination of R. parkeri to draining lymph nodes early in infection and increased persistence at the inoculation site were observed in the tick plus R. parkeri group. This study indicates that rhesus macaques can be used to model R. parkeri rickettsiosis, and suggests that immunomodulatory factors introduced during tick feeding may enhance the pathogenicity of spotted fever group Rickettsia.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.