Diversity of rickettsiae and potential vectors of spotted fever in an area of epidemiological interest in the Cerrado biome, midwestern Brazil

Abstract

The Brazilian state of Goiás, untouched by spotted fever (SF) until 2012, has subsequently reported cases of the disease in several regions. This study aimed to survey the diversity of potential vectors and rickettsia in areas of Goiás under environmental surveillance or case investigation for SF. Collected specimens were assayed with molecular biology technology using DNA extraction, amplification and sequencing of fragments of the genes gltA, ompA, ompB and sca4 to detect rickettsia in ticks and fleas. Amplification of cytochrome oxidase subunit II and 16S rRNA was performed to assist tick identification. Rickettsia felis (Rickettsiales: Rickettsiaceae) was found in Ctenocephalides felis (Bouché, 1835) (Siphonaptera: Pulicidae). Rickettsia bellii was found in Amblyomma rotundatum Koch, 1844 (Ixodida: Ixodidae) and in Amblyomma cajennense sensu lato. Rickettsia sp. strain NOD was found in Amblyomma nodosum Neumann, 1899. Of the Amblyomma cajennense complex, Amblyomma sculptum Berlese, 1888 was confirmed in the northern, northeast, midwest and southeast regions of Goiás, whereas Amblyomma cajennense sensu stricto (Fabricius, 1787) was found only in the northern region of the state. Amblyomma dubitatum Neumann, 1899 associated with a species of the A. cajennense complex was the most common epidemiological finding, although Rickettsia rickettsii was not detected. This is the first report of Rickettsia sp. strain NOD in Goiás.

Molecular detection of spotted fever group rickettsiae in hard ticks, northern China

“…The circulation of these three SFG rickettsiae species provides a basis for monitoring of their infection in humans. Only one SFG rickettsiae species was identified in each sampling site in our study, and this geographical distribution of SFG rickettsiae was inconsistent with previous studies (Kang et al, ; Machado et al, ).…”

Spotted Fever in the Morphoclimatic Domains of Minas Gerais State, Brazil

“…However, knowledge of the epidemiology and dynamics of human infection remains insipient in the various PSIs across the country (2), complicating appropriate public health actions to inform the general population and control the disease. In addition, studies progressed, different species of Rickettsia spp./ Spotted Fever group, related to different species of ticks, have been detected in Brazil, whether or not they are linked to SF outbreaks (6,7,(11)(12)(13)(14)(15). This has demonstrated the great biodiversity of Rickettsiae and potential vectors, and highlighting the potential complexity of the mechanisms by which these microorganisms might circulate within the country, and the danger for the appearance of new outbreaks.…”

Parasitism of a capybara (Hydrochoerus hydrochaeris) by Amblyomma nodosum Neumann, 1899 and Amblyomma humerale Koch, 1844 in an Amazon forest area, Rondônia, Brazil

“…Its parasitism on a lizard has also been described by Zimmermann et al (2018) in the same state. In addition to the veterinary importance of ticks as animal parasites, several reports have shown the detection of microorganisms in A. nodosum and A. humerale such as Rickettsiae, what could eventually be related to human health risks (Labruna et al, 2004;Ogrzewalska et al, 2009;Almeida et al, 2013;Soares et al, 2015;Witter et al, 2016;Machado et al, 2018;Moerbeck et al, 2018). This justifies the interest in conducting research on these ectoparasites in areas rich in biodiversity, especially the Amazon region.…”

“…There are several reports of the tick A. nodosum in Brazil, parasitizing mainly anteaters in various regions of the country, including the states of Mato Grosso, Goiás, Ceará (Witter et al, 2016;Machado et al, 2018;Moerbeck et al, 2018), Mato Grosso do Sul (Garcia et al, 2013) and Rondônia (Zimmermann et al, 2018). The occurrence of A. nodosum in Rondônia has been reported since 2005, where these ticks were found by Labruna et al (2005) and Martins et al (2014) on anteaters in different municipalities.…”