Diagnosis of fasciolosis antibodies in Brazilian cattle through ELISA employing both native and recombinant antigens

Bovine fasciolosis is a parasitic disease with a global reach. Coprological based on egg detection in fecal samples and liver inspection to evaluate the presence of the parasite is currently the gold standard for diagnosing chronic fasciolosis in cattle. However, these techniques are labor-intensive and ineffective during the acute phase of the disease. Serodiagnosis using native and recombinant antigens has become an interesting alternative in efforts to identify cattle fasciolosis. We evaluated cattle from abattoir (n = 139) and farms (n = 500) through liver inspection and coprological examination, respectively. Our laboratory team optimized and validated enzyme-linked immunosorbent assay tests based on somatic antigen, excretory/secretory proteins, and the recombinant antigen cathepsin L-1 to detect serum antibodies against fasciolosis in cattle. For animals from abattoir, 10 were positive for fasciolosis according to liver inspection. Both FhES and FhrCL-1 presented an area under the receiver operating characteristic (AUROC) curve of 0.80, with a sensitivity of 0.80 (95% CI: 0.46-0.95) and 0.70 (95% CI: 0.38-0.90) and specificity of 0.81 (95% CI: 0.73-0.87) and 0.87 (95% CI: 0.80-0.92), respectively. For those cattle from farms, 28 were positive only for fasciolosis according to coprological examination. In this scenario, FhES gave the best performance, with an AUROC of 0.84, sensitivity of 0.79 (95% CI: 0.60-0.90), and specificity of 0.86 (95% CI: 0.82-0.89). In conclusion, our study highlights the potential of serodiagnosis for accurately screening cattle fasciolosis. The promising sensitivity and specificity values of FhES when compared to liver inspection or coprological examination enhance its importance for cattle fasciolosis diagnosis.

IMPORTANCE

The aim of this article was to identify antibodies against fasciolosis in cattle in Brazil. The methodology was reproduced in our laboratory and applied for the first time to the Brazilian cattle herd. The antigens tested can be used as a screening test and thus speed up the diagnosis of bovine fascioliasis.

Serological diagnosis of fasciolosis (Fasciola hepatica) in humans, cattle, and sheep: a meta-analysis

Fasciola hepatica can cause problems in both animals and humans. Fasciolosis can be diagnosed through the indirect ELISA immunodiagnostic test. Serological diagnosis of Fasciola is based on recombinant antigens secreted by this worm. We used PubMed and Google Scholar databases to review the published literature on 'antigens with immunogenic potential' used in serological tests to identify antibodies against F. hepatica in humans, cattle, and sheep. Studies that investigated diagnostic tests with common reference standards were included in the sensitivity and/or specificity bivariate meta-analysis. In the quality and susceptibility to bias analysis of the 33 included studies, 26 fulfilled at least six (75%) of the eight QUADAS criteria and were considered good-quality papers. We found that most of the studies used native excretory-secretory antigens and recombinant cathepsin in ELISA tests for serological diagnosis of fascioliasis in humans, cattle, and sheep. The meta-analysis revealed that all antigens demonstrated good accuracy. The best results in terms of sensitivity [0.931-2.5% confidence interval (CI) and 0.985-97.5% CI] and specificity (0.959-2.5% CI and 0.997-97.5% CI) were found in human FhES. FhrCL-1, FhES, and FhrSAP-2 antigens gave the best results for the serum diagnosis of human and animal fasciolosis.

Cryptosporidium spp. in Aratinga jandaia, Diopsittaca nobilis and Pionus menstruus in Brazil

Background: Cryptosporidium is an important protozoan in public health and veterinary medicine that often causes diarrhea in an array of hosts in developed/developing countries. Infection of the gastrointestinal system is the most common, but the respiratory system and other sites can also be affected, especially in birds and immunocompromised individuals. Transmission occurs through ingestion or inhalation of oocysts. The number of wild animals, including those in the class of birds, infected with this parasite has grown in recent years. This study aimed to report parasitism by Cryptosporidium spp. in captive-raised birds of family Psittacidae at the Rio City Zoo in Rio de Janeiro, Brazil.Materials, Methods & Results: Thirty-three pools of fecal samples of the species Amazona aestiva, Amazona amazonica, Anodorhynchus hyacinthinus, Ara auricollis, Ara canga, Ara glaucogularis, Ara macao, Ara manilapa, Ara maracana, Ara rubrogenys, Aratinga erythrogenys, Aratinga cactorum, Aratinga auerea, Aratinga mitrata, Aratinga auricapilla, Aratinga jandaia, Aratinga wagleri, Aratinga leucophthalmus, Brotogeris acuticaudata, Cynoliseus patagonus, Caracopsis vasa, Diopsittaca nobilis, Graydidascalus brachyurus, Muopsitta monachus, Nangayus nenday, Pionites melancephala, Pionites leucogaster, Pionus menstruus, Pionus chalcopteus, Pionus maxiliani, Pyrrhura perlata, Pyrrhura leucotis, and Triclharia malachitacea, kept in separate enclosures, were analyzed using Enzyme-linked Immunosorbent Assay (ELISA) for detection of parasitic antigens. Quantitative Polymerase Chain Reaction (qPCR) was conducted in order to identify the species Cryptosporidium in the positive samples targeting the small subunit ribosomal RNA gene (SSU rRNA), followed by sequencing and analysis of the DNA amplicons. Cryptosporidium spp. antigen was detected in three (9%) of the thirtythree pools assessed, corresponding to the following species of family Psittacidae: Jandaya parakeet (Aratinga jandaya), Red-shouldered macaw (Diopsittaca nobilis), and Blue-headed parrot (Pionus menstruus). Positivity of the three samples was confirmed by qPCR analysis, but it was not possible to identify the species of Cryptosporidium by this technique.Discussion: Zoonotic diseases, such as cryptosporidiosis, have been reported in wild and captive-bred animals worldwide. Several species of the class of birds are parasitized by Cryptosporidium spp. Infection in order Psittaciformes has been described in some species raised in captivity in Brazil; however, no reports of Cryptosporidium spp. infecting the following species of order Psittaciformes: Jandaya parakeet (Aratinga jandaia), Red-breasted macaw (Diopsittaca nobilis), and Blue-headed parrot (Pionus menstrus), were found in the specific scientific literature. The present study detected infection by Cryptosporidium spp. in three species of order Psittaciformes using ELISA and confirmed the positivity of the samples by qPCR, but the species of Cryptosporidium could not be identified. These infected birds should be carefully investigated, with identification of the species and analysis of their zoonotic potential, because they can be sources of environmental contamination and infection for the caregivers, visitors, and other animals of the Zoo. This is the first report of parasitism by Cryptosporidium spp. in these species of family Psittacidae in Brazil.