Abstract
Rickettsia rickettsii is the causative agent of Brazilian spotted fever (BSF), for which humans and dogs are both susceptible. Dogs are sentinels in serological surveys, however, canine disease is rarely reported. Therefore, we aimed to evaluate natural infection by spotted fever group (SFG) Rickettsia spp. in dogs and ticks collected from domiciles close to forest fragments, featuring domestic-wildlife interface areas. Samples from 115 dogs and 135 ixodids were assessed by polymerase chain reactions (PCR) targeting the gltA gene for Rickettsia spp. and the ompA gene for the SFG rickettsial species. One dog (0.87%; 1/115) was positive for R. rickettsii. This dog presented nonspecific laboratory and clinical abnormalities (thrombocytopenia, hyperproteinemia, lymph node enlargement, emaciation, anorexia, and lethargy). Rickettsia parkeri was identified in 2.96% (4/135) of the ticks (Amblyomma sculptum, A. aureolatum, and Rhipicephalus sanguineus). This study confirmed the presence of SFG bacteria in non-endemic and preserved locations, where domestic and wild populations interact. We reinforce the fact that the dog is susceptible to natural R. rickettsii infection. Although this is a rare finding, preventive measures should be taken against BSF in the studied areas. Finally, R. parkeri infection is possibly being demonstrated in A. sculptum for the first time.
Highlights
Bacteria of the genus Rickettsia are obligate intracellular organisms
Considering the geographical location of the state of Rio de Janeiro (RJ); the lack of studies in environments protected by law; and in view of the ecological and epidemiological aspects of spotted fever group (SFG) rickettsiosis, this study aimed to evaluate the natural occurrence of SFG Rickettsia spp. in dogs and their ticks collected from conservation units (CUs) in the Atlantic Forest biome of RJ state and surrounding areas
The outer membrane protein A (ompA) sequence demonstrated 100% identity and 100% query coverage with R. rickettsii obtained from Amblyomma tick egg masses from Mexico
Summary
Bacteria of the genus Rickettsia are obligate intracellular organisms. In Brazil, Rickettsia rickettsii and Rickettsia sp. str. In Brazil, Rickettsia rickettsii and Rickettsia sp. Atlantic Rainforest are the main SFG rickettsiosis-causing bacteria that leads to human disease (Oliveira et al, 2016). Rickettsia rickettsii is the etiological agent of the human Brazilian spotted fever (BSF), a severe tick-borne disease, endemic in southeastern Brazil, which can reach a mortality rate of 50% (Oliveira et al, 2016). In this country, 1,574 human cases of BSF were reported between 2001 and 2017; 1,128 (71.66%) of those cases occurring in the southeastern region (Brasil, 2019). Dogs are susceptible to R. rickettsii infection, and these are considered sentinels in serological surveys (based on the presence of antibodies), natural illness has rarely been reported in canines in Brazil (Labruna et al, 2009)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology : Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
