Molecular Evidence for a Spotted Fever GroupRickettsiaSpecies in the TickAmblyomma longirostrein Brazil

Abstract

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.

Tick-Borne Rickettsioses around the World: Emerging Diseases Challenging Old Concepts

“…Because lone star ticks are especially abundant in the southern and midwestern United States, and because A. americanum of all three stages readily bite humans, infections with R. amblyommii could prove to be relatively frequent if this agent is definitively identified as a human pathogen. Recent investigations have also identified a spotted fever group rickettsia (strain Aranha) in Amblyomma longirostre ticks collected from Brazil that shows a very close phylogenetic relationship with R. amblyommii (167). To our knowledge, no isolate of R. amblyommii is currently available to the scientific community.…”

Parasitismo por Giardia sp. e Cryptosporidium sp. em Coendou villosus

“…), hemoparasitas (Hepatozoon sp., Babesia sp., Trypanosoma sp. e filárias) e endoparasitas (Prosthenorchis luhei, Hymenolepis diminuta e Trichuris opaca) (CATTO, 2000;THOISY et al, 2000;BRUM et al, 2003;LABRUNA et al, 2004;KUNIY & BRASILEIRO, 2006).…”

Occurrence of Amblyomma longirostre in Cyanocompsa brissonii in Rio Grande do Sul, Brazil

“…According to LABRUNA et al (2004), two adult specimens of A. longirostre that were collected from Coendu prehensilis (Linnaeus, 1758) in the state of Rondônia, Brazil, were positive for a strain of Rickettsia belonging to the macular fever group. This was then named "aranha" (spider) strain.…”