Investigação sorológica de Rickettsia rickettsii e Coxiella burnetii em caprinos e ovinos no entorno do Parque Nacional da Serra das Confusões, Piauí

Abstract

RESUMO: As doenças causadas por bactérias dos gêneros Rickettsia e Coxiella possuem como vetores artrópodes hematófagos, na sua maioria carrapatos, que atuam diretamente na transmissão de patógenos responsáveis por enfermidades de grande impacto na medicina veterinária e humana. O presente estudo objetivou realizar uma investigação sorológica de Rickettsia rickettsii e Coxiella burnetii em caprinos e ovinos criados no entorno do Parque Nacional da Serra das Confusões (PNSC), localizado no estado do Piauí, região nordeste do Brasil. Amostras de soro de 202 caprinos e 153 ovinos foram testadas pela Reação de Imunofluorescência Indireta (RIFI) para detecção de anticorpos anti-R. rickettsii e anti-C. burnetii, sendo consideradas positivas quando apresentaram títulos ≥ 64. Carrapatos em fase de parasitismo foram coletados e identificados. Todas as amostras de caprinos e ovinos foram soronegativas para antígenos de R. rickettsii. Foi verificado soropositividade em 2% (3/153) das amostras de ovinos para C. burnetii, com títulos variando de 64 a 4.096. As amostras de caprinos não foram reagentes ao referido antígeno. Não foi observado parasitismo em caprinos por carrapatos. No total, foram coletados 56 carrapatos parasitando 15 ovinos (9,8%), todos identificados como Rhipicephalus microplus. O estudo demonstrou a ausência de anticorpos anti-R. rickettsii nas amostras de caprinos e ovinos, ausência de anticorpos anti-C. burnetii em caprinos; e possibilitou o primeiro relato da ocorrência sorológica de C. burnetii em ovinos nesta região do Brasil.

Serological evidence of Rickettsia in horses from a semi-arid Brazilian region

“…These findings suggest the exposure of horses to this microorganism, especially because the seropositive animals did not have a travel history to other locations. Moreover, one animal had a high endpoint titer (2,048), suggesting recent exposure to rickettsiae (Ueno et al, 2016;Guimarães et al, 2017). Furthermore, we clearly demonstrated the reactivity of horse sera to R. rickettsii antigens.…”

Serological diagnosis and risk factors for Coxiella burnetii in goats and sheep in a semi-arid region of Northeastern Brazil

“…While we found a relatively low seroprevalence for C. burnetii (<3.3%) among sheep and goat, it is noteworthy that half of the seropositive animals had high endpoint titers, varying from 1,024 to 65,536 (Table 1). High endpoint titers are suggestive of recent infection (GUIMARÃES et al, 2017;OLIVEIRA et al, 2018); however, we cannot discard cross-reactions with other unknown agents in some of our seropositive animals, especially those with low endpoint titers. Regardless, the overall low seroprevalence values in the present study are similar to the 2% (3/153) seroprevalence on sheep that was reported in another study from the Caatinga Biome (south of Piauí state) in northeastern Brazil (GUIMARÃES et al, 2017).…”

“…High endpoint titers are suggestive of recent infection (GUIMARÃES et al, 2017;OLIVEIRA et al, 2018); however, we cannot discard cross-reactions with other unknown agents in some of our seropositive animals, especially those with low endpoint titers. Regardless, the overall low seroprevalence values in the present study are similar to the 2% (3/153) seroprevalence on sheep that was reported in another study from the Caatinga Biome (south of Piauí state) in northeastern Brazil (GUIMARÃES et al, 2017). In contrast, much higher seropositivity to C. burnetii has been reported among goats in the Agreste of the state of Alagoas (55.1%; 172/312) (OLIVEIRA et al 2018), and in the Atlantic forest Biome of Rio de Janeiro state, where 66.6% (2/3) of sheep and 50% (5/10) of goats were seropositive (MARES-GUIA et al, 2014).…”

“…In Brazil, the presence of C. burnetii in humans has been reported by serological and/or molecular assays in the states of São Paulo (BRANDÃO et al, 1953;VALLE et al, 1955;SICILIANO et al, 2015), Rio de Janeiro (LAMAS et al, , 2013LEMOS et al, 2011LEMOS et al, , 2018ROZENTAL et al, 2012;MARES-GUIA et al, 2016), Minas Gerais (RIEMANN, et al, 1974;COSTA et al, 2005COSTA et al, , 2006 and Bahia (SICILIANO et al, 2008). Among three Brazilian states (Rio de Janeiro, Piauí, and Alagoas), seropositive reactions to C. burnetii have been identified in dogs, sheep and/or goats, and/or C. burnetii DNA has been amplified from goat milk or placenta, or dog blood (MARES-GUIA et al, 2014;GUIMARÃES et al, 2017;OLIVEIRA et al 2018). Therefore, this zoonotic disease was included in Brazil's list of notifiable diseases in 2013 (BRASIL, 2013).…”

Q fever and coxiellosis in Brazil: an underestimated disease? A brief review

“…Of these, the anti-C. burnetii antibodies was observed through the IFA test (phase I and phase II) in two (14.3%) dogs with endpoint titers of 64, five (50%) goats with endpoint titers ranging from 64 to 128, and two (66.7%) sheep with endpoint titers of 64, as well as bacterial DNA in six (60%) milk samples, two (14.3%) dog blood samples, and two (20%) goat blood samples (Mares-Guia et al, 2014). In 2017, the presence of 1.96% of anti-C. burnetii antibodies using the IFA test (no phase I or phase II specification) from 153 sheep studied in Piauí State with titers ranging from 64 to 4,096 was confirmed (Guimarães et al, 2017). In 2018, seropositivity of 55.12% for C. burnetii among 312 goats was reported, in Alagoas State, through the ELISA test, with 65.7% of the serorreactives presenting high titers (≥ELISA++).…”