The anal pore route is efficient to infect Amblyomma spp. ticks with Rickettsia rickettsii and allows the assessment of the role played by infection control targets

Front Cell Infect Microbiol. 2023 Oct 12:13:1260390. doi: 10.3389/fcimb.2023.1260390. eCollection 2023.

Abstract

Adult Amblyomma sculptum and Amblyomma aureolatum ticks are partially refractory to Rickettsia rickettsii when fed on infected hosts, hindering the functional characterization of potentially protective targets in the bacterial acquisition. In the current study, we used the anal pore route to infect adult A. sculptum and A. aureolatum ticks with R. rickettsii and to assess the effects of the knockdown of microplusin in infection control. The anal pore route was efficient to infect both species, resulting in a prevalence of around 100% of infected ticks. Higher loads of R. rickettsii were detected in microplusin-silenced A. aureolatum in relation to the control, as previously obtained when microplusin-silenced ticks were fed on R. rickettsii-infected rabbits. This is the first report showing R. rickettsii infection through the anal pore in Amblyomma ticks, highlighting this route as a powerful tool to assess the role played by additional targets in the control of pathogens.

Keywords: RNA interference; anal pore; immune factors; microplusin; rickettsiae; tick.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amblyomma
  • Animals
  • Brazil / epidemiology
  • Ixodidae* / microbiology
  • Rabbits
  • Rickettsia rickettsii
  • Rickettsia*
  • Rocky Mountain Spotted Fever* / microbiology
  • Ticks* / microbiology

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by funds from: the São Paulo Research Foundation (FAPESP) by Grants 2013/26450-2, 2020/16462-7, and 2021/03649-4; the National Council for Scientific and Technological Development [CNPq; Grants CNPq 573959/2008-0; the National Institutes of Science and Technology Program in Molecular Entomology (INCTEM)]; and the Coordination for the Improvement of Higher Education Personnel (CAPES). MBN (88887694216202200) and EE (8888321638/2019-00) were supported by fellowships from CAPES; DP was supported by a fellowship from FAPESP (2018/00652-1). AF (309733/2018-9) and SD (304382/2017-5) received CNPq research productivity scholarships.