Gastrointestinal parasites among felids inhabiting the Serra dos Órgãos National Park, Rio de Janeiro, Brazil

Toxoplasma gondii in the faeces of wild felids from the Atlantic Forest, Brazil

BACKGROUND

Toxoplasma gondii is a apicomplexan parasite of virtually all warm-blooded species. All true cats (Felidae) can act as definitive hosts for this parasite by shedding resistant oocysts into the environment. However, the patterns of oocysts shedding are only partially understood in domestic cats and largely unknown in wild felids.

OBJECTIVES

We carried out molecular analysis of 82 faecal samples from wild felids collected in the Serra dos Órgãos National Park (Parnaso), Rio de Janeiro, Brazil.

METHODS

We screened samples for T. gondii DNA using a quantitative polymerase chain reaction (qPCR) targeting the 529bp DNA fragment. Polymerase chain reaction (PCR)-positive samples were genotyped using 15 microsatellite markers.

RESULTS

Only one faecal sample from a Puma yagouaroundi was PCR-positive [cycle threshold (Ct) = 26.88]. This sample was contaminated by a T. gondii strain of BrIII lineage, a common lineage in domestic animals from Brazil.

MAIN CONCLUSIONS

This first report of T. gondii in faeces of wild South American felids in their natural environment indicates infrequent oocyst shedding and suggests a role of acquired immunity in limiting re-excretion as in domestic cats. The presence of a domestic strain of T. gondii in a faecal sample from a wild felid at very low concentrations (not detected by microscopy) is consistent with the hypothesis of host-parasite co-adaptations limiting the circulation of T. gondii strains between domestic and wild environments.

Parasites in road-killed wild felines from North of Paraná state, Brazil

This study aimed to identify the intestinal parasites of road-killed wild felines in the North Central and North, Paraná state, southern Brazil. The animals were monitored by sampling previously established transects. The places where the felines were run over were mapped, the animals were identified, and the gastrointestinal tract was evaluated. The feces were submitted to coproparasitological techniques of spontaneous sedimentation, floating in hypersaturated NaCl solution and centrifugal floating in zinc sulfate. All the parasitic structures detected were photomicrographed. In the coproparasitological analyses were identified oocysts of Cystoisospora spp., eggs of Ancylostomatidae, and Capillaria spp.; eggs of Aelurostrongylus spp., Toxocara spp., Physaloptera spp., Taenia spp., and Spirometra spp.; Aelurostrongylus abstrusus larvae; and eggs and adults of Ancylostoma cati and Taenia spp. One of the cats was parasitized by a flea of Ctenocephalides felis felis. Based on these results, the animals analyzed in this study supplied important samples for the evaluation of parasitic diversity of North of Paraná and suggested that this region may have conditions that allow the maintenance of these parasites life cycles in the environment and among wildlife.

Non-invasive sampling in Itatiaia National Park, Brazil: wild mammal parasite detection

Background

Non-invasive sampling through faecal collection is one of the most cost-effective alternatives for monitoring of free-living wild mammals, as it provides information on animal taxonomy as well as the dynamics of the gastrointestinal parasites that potentially infect these animals. In this context, this study aimed to perform an epidemiological survey of gastrointestinal parasites using non-invasive faecal samples from carnivores and artiodactyls identified by stool macroscopy, guard hair morphology and DNA sequencing in Itatiaia National Park. Between 2017 and 2018, faeces from carnivores and artiodactyls were collected along trails in the park. The host species were identified through macroscopic and trichological examinations and molecular biology. To investigate the parasites, the Faust, Lutz and modified Ritchie and Sheather techniques and enzyme immunoassays to detect Cryptosporidium sp. antigens were used.

Results

A total of 244 stool samples were collected. The species identified were Chrysocyon brachyurus, Leopardus guttulus, Canis familiaris, Cerdocyon thous, Puma yagouaroundi, Leopardus pardalis, Puma concolor and Sus scrofa. There were 81.1% samples that were positive for parasites distributed mainly in the high part of the park. Helminths, especially eggs of the family Ascarididae, were more frequently detected in carnivore faeces (70.9%). Protozoa, especially Cryptosporidium sp., represented the highest frequency of infection in artiodactyl faeces (87.1%). This zoonotic protozoon was detected in eight mammalian species, including in a wild boar. High values of structural richness and Shannon and Simpson diversity indices were observed for the parasites, especially in the faeces of C. brachyurus. Significant differences in parasite diversity were observed between wild and domestic animals, such as C. brachyurus and C. familiaris, respectively, and between taxonomically distant species, such as C. brachyurus and S. scrofa. The highest values for parasite similarity were found among the species that frequented similar areas of the park, such as C. brachyurus and L. guttulus.

Conclusions

The animals and parasite infections were identified through the combination of three techniques. High frequency parasite structures were diagnosed. Zoonotic protozoa were found and mainly occurred in samples from introduced species.

First case report of nematode parasitic myelopathy in a wild feline in Brazil

Parasitic myelopathy caused by Gurltia paralysans in domestic cats is a disease commonly reported in several South American countries. The adult parasite is lodged in the meningeal veins and spinal cord, often causing clinical manifestations of vascular proliferation, thrombophlebitis, and medullary compression. Wild felines are believed to be the definitive hosts of this parasite. The infection occurs through the ingestion of paratenic hosts, but the life cycle of G. paralysans is not yet clearly understood. In this paper, we discuss a case of parasitic myelopathy in a margay (Leopardus wiedii) that died during post-surgical care. Necropsy revealed focal hemorrhages in the thoracolumbar spinal cord. A microscopic examination revealed adult nematodes and eggs inside the veins of subarachnoid space in spinal cord, suggesting G. paralysans infection. This is first description of parasitic myelopathy in a margay in Brazil.

Comparison of Four Parasitological Techniques for Laboratory Diagnosis of Eggs from Spirometra spp. in Wild Mammal Fecal Samples

PURPOSE

This study aimed to compare the performance of four different microscopic coproparasitological techniques in relation to egg recovering and the frequency of alterations in the eggs observed through each technique.

METHODS

A total of 213 fecal samples from free-living carnivorous mammals were collected between 2017 and 2018 in Itatiaia National Park, RJ, Brazil. Faust and modified Sheather floatation techniques as well as Lutz and modified Ritchie sedimentation techniques were applied.

RESULTS

The total positivity rate for Spirometra spp. eggs was 24.4%, and these were detected mainly through Lutz and modified Ritchie sedimentation techniques, with substantial agreement (kappa = 0.73; p = 0.00 < 0.05; McNemar p value = 1.0; Fisher's exact test p = 0.616). Faust and modified Sheather flotation techniques did not present good egg recovery, with frequencies of 6.6% and 7.5%, respectively. Eggs with morphological alterations were mostly observed through Faust (17.3%) and modified Sheather (13.5%). Both flotation techniques presented statistically significant frequencies of deformed eggs, in comparison with the sedimentation techniques (p = 0.00). Low frequencies of deformed eggs were observed when the samples were analyzed through modified Ritchie and Lutz sedimentation techniques.

CONCLUSIONS

From these results, sedimentation techniques such as modified Ritchie and Lutz methods were more efficient for diagnosing the eggs of this helminth in fecal material from free-living carnivores and should always be used when analyzing fecal samples from hosts of different species.