Investigação de anticorpos contra Sarcocystis neurona e Sarcocystis cruzi em equinos

The aim of this study was to determine the prevalence of infection by Sarcocystis neurona in horses and identify potential risk factors. Were analyzed 427 samples from 36 farms in 21 municipalities in the Alagoas State, Brazil. Presence of anti-S. neurona antibodies was diagnosed by indirect immunofluorescence antibody test (IFAT) and was confirmed using the immunoblot test. Risk factors were assessed through investigative questionnaires on animal management on the farms. The prevalence of anti-S.neurona antibodies was 2.8% (confidence interval, CI: 1.5-4.9%) from IFAT and 1.6% (CI:0.8-3.34%) from immunoblot, and there were positive horses on 16.6% of the studied farms. None of the variables studied presented associations with serological status for S. neurona. This is the first report on infection by S. neurona in horses reared in Alagoas, Brazil showing a low exposure to S. neurona in this region, but with significant numbers of foci.

Section: Results Discussion and Conclusionmentioning

confidence: 99%

Low prevalence of infection by Sarcocystis neurona in horses from the State of Alagoas, Brazil

Valença

Ribeiro-Andrade

Moré

et al. 2019

“…This is a high seroprevalence compared to previous investigations conducted in Brazil. These include horse serum analyzed by IFAT in the states of Alagoas (Northeast, 2.8%) ( Valença et al, 2019 ), Mato Grosso (Midwestern, 20.8%) ( Borges et al, 2017 ), Minas Gerais (Southeastern, 23.09%) ( Ribeiro et al, 2016 ), Rio Grande do Sul (South, 33.86%) ( Antonello et al, 2015 ), São Paulo (Southeastern, 23.8%) ( Oliveira et al, 2017 ) and Roraima (North, 40.4%) ( Gomes et al, 2019 ). In the present study, the highest titer observed for S. neurona was 1:800, whereas 1:400 was the highest titer observed for S. falcatula- like.…”

Section: Resultsmentioning

confidence: 99%

“…Confirmation of IFAT using immunoblot assays revealed a low number of “true positive” samples in horse sera tested against S. neurona (SN37R) in the state of Alagoas ( Valença et al, 2019 ). In an IFAT survey performed with serum samples from 189 mares, 57 from the 64 samples that reacted against S neurona , reacted also against Sarcocystis cruzy , i.e., only seven samples reacted solely against S. neurona ( Antonello et al, 2015 ). The presence of specific antibodies in serum and cerebrospinal fluid, associated with typical clinical signs, and the complete differential diagnosis, is currently used to define EPM diagnosis ( Dubey et al, 2015 ).…”

Section: Resultsmentioning

confidence: 99%

Reactivity against Sarcocystis neurona and Sarcocystis falcatula-like in horses from Southeastern and Midwestern Brazil

Silva

Santi

Gonçalves³

et al. 2023

Equine protozoal myeloencephalitis (EPM) is a neurological disease caused by Sarcocystis neurona. Immunofluorescence antibody tests (IFATs) have been widely used to identify exposure of horses to S. neurona in Brazil. Here we used IFAT to search for IgG antibodies against Sarcocystis falcatula-like (Dal-CG23) and S. neurona (SN138) in sera from 342 horses sampled in Campo Grande, Mato Grosso do Sul state (Midwestern), and São Paulo, São Paulo state (Southeastern), Brazil. The 1:25 cutoff value was chosen to maximize sensitivity of the test. IgG antibodies against S. neurona were detected in 239 horses (69.88%), whereas IgG antibodies against S. falcatula-like were detected in 177 horses (51.75%). Sera from 132 horses (38.59%) reacted against both isolates. Absence of reactivity was evidenced in 58/342 horses (16.95%). The lower cutoff used, and the presence of opossums infected with S. falcatula-like and Sarcocystis spp. in the regions where the horses were sampled, might justify the high seroprevalence observed here. Owing to the similarity among antigens targeted in immunoassays, reports on S. neurona-seropositive horses in Brazil may also derive from the exposure of horses to other Sarcocystis species. The role of other Sarcocystis species in causing neurological diseases in horses in Brazil remains unclear.

“…IFAT has been conducted with cutoffs between 1:20 and 1:80. Even in some studies using low cutoffs (1:25 or 1:50), the frequencies of antibodies in horses were below 50% (Antonello et al, 2015;Cazarotto et al, 2016;Koch et al, 2019;Portella et al, 2017;Spohr et al, 2018). It is noteworthy that serological studies conducted using SnSAG4 ELISA reported higher antibody frequencies (higher than 60% in most regions) than studies conducted using IFAT (Table 2).…”

Section: Serological Studies On South American Horsesmentioning

confidence: 94%

Sarcocystis neurona and related Sarcocystis spp. shed by opossums (Didelphis spp.) in South America

Gondim

Soares

Moré

et al. 2021

Protozoan parasites of the genus Sarcocystis are obligatory heteroxenous cyst-forming coccidia that infect a wide variety of animals and encompass approximately 200 described species. At least four Sarcocystis spp. (S. falcatula, S. neurona, S. lindsayi and S. speeri) use opossums (Didelphis spp.) as definitive hosts, and two of them, S. neurona and S. falcatula, are known to cause disease in horses and birds, respectively. Opossums are restricted to the Americas, but their distribution in the Americas is heterogeneous. Five Didelphis spp. are distributed in South America (D. aurita, D. albiventris, D. marsupialis, D. imperfecta and D. pernigra) whereas just one opossum species (D. virginiana) is found in North America. Studies conducted in the last decades show that Sarcocystis spp., derived from South American Didelphis spp., have biological and genetic differences in relation to Sarcocystis spp. shed by the North American opossum D. virginiana. The aim of this review was to address the peculiar scenario of Sarcocystis species shed by South American opossums, with a special focus on diagnosis, epidemiology, and animal infections, as well as the genetic characteristics of these parasites.