Molecular evidence for a spotted fever group Rickettsia species in the tick Amblyomma longirostre in Brazil

Marcelo B. Labruna, Jere W. Mcbride, Donald H. Bouyer, Luis Marcelo A. Camargo, Erney P. Camargo, David H. Walker

Research output: Contribution to journalArticlepeer-review

111 Scopus citations


Two Amblyomma longirostre adult male ticks were collected from a Brazilian porcupine Coendou prehensilis L. in the state of Rondonia, Western Amazon, Brazil. The two ticks were pooled for DNA extraction and tested for the presence of rickettsial DNA by amplifying portions of the gltA, 17-kDa, ompA, and ompB rickettsial genes by polymerase chain reaction (PCR). Portions of the four genes were amplified from the sample and subsequently sequenced. These results indicated the presence of a Rickettsia strain infecting A. longirostre, which was designated as strain Aranha. Compared with homologous ompA rickettsial sequences, "Rickettsia amblyommii" ompA seemed to be the closest relative to Aranha (similarity values: 99.0-99.3%). Phylogenetic analyses of more conserved genes including 17-kDa and gtlA partial sequences indicated that this Rickettsia sp. is a spotted fever group rickettsia. The partial ompB sequence of strain Aranha was distinct from all homologous sequences available in GenBank. Although our ompA analysis suggested a very close molecular phylogenetic relationship of Aranha with "R. amblyommii," we cannot at this time determine if Aranha is a new strain of "R. amblyommii" or a new Rickettsia species in South America.

Original languageEnglish (US)
Pages (from-to)533-537
Number of pages5
JournalJournal of medical entomology
Issue number3
StatePublished - May 2004


  • Amblyomma longirostre
  • Brazil
  • Rickettsia
  • Rondonia
  • Ticks

ASJC Scopus subject areas

  • Parasitology
  • General Veterinary
  • Insect Science
  • Infectious Diseases


Dive into the research topics of 'Molecular evidence for a spotted fever group Rickettsia species in the tick Amblyomma longirostre in Brazil'. Together they form a unique fingerprint.

Cite this