BackgroundSchistosomiasis is a major endemic disease that affects hundreds of millions worldwide. Since the treatment and control of this parasitic disease rely on a single drug, praziquantel, it is imperative that new effective drugs are developed. Here, we report that phytol, a diterpene alcohol from chlorophyll widely used as a food additive and in medicinal fields, possesses promising antischistosomal properties in vitro and in a mouse model of schistosomiasis mansoni.Methods and findings In vitro, phytol reduced the motor activity of worms, caused their death and confocal laser scanning microscopy analysis showed extensive tegumental alterations in a concentration-dependent manner (50 to 100 µg/mL). Additionally, phytol at sublethal doses (25 µg/mL) reduced the number of Schistosoma mansoni eggs. In vivo, a single dose of phytol (40 mg/kg) administered orally to mice infected with adult S. mansoni resulted in total and female worm burden reductions of 51.2% and 70.3%, respectively. Moreover, phytol reduced the number of eggs in faeces (76.6%) and the frequency of immature eggs (oogram pattern) was significantly reduced. The oogram also showed increases in the proportion of dead eggs. Confocal microcopy studies revealed tegumental damage in adult S. mansoni recovered from mice, especially in female worms.ConclusionsThe significant reduction in parasite burden by this chlorophyll molecule validates phytol as a promising drug and offers the potential of a new direction for chemotherapy of human schistosomiasis. Phytol is a common food additive and nonmutagenic, with satisfactory safety. Thus, phytol has potential as a safe and cost-effective addition to antischistosomal therapy.

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Cytauxzoon spp. DNA was detected for the first time in blood samples from asymptomatic Brazilian wild captive felids. In 2006, 72 EDTA blood samples from seven wild felids species: Puma concolor (puma), Leopardus pardalis (ocelot), Puma yagouaroundi (jaguarundi), Leopardus wiedii (margay), Leopardus tigrinus (little spotted cat), Oncifelis colocolo (pampas cat) and Panthera onca (jaguar) were analyzed using polymerase chain reaction to amplify the 18S rRNA gene segment in order to verify the presence of Cytauxzoon spp. DNA. Nine samples were positive: six ocelots, two pumas, and one jaguar. In Brazil, wild felids may be natural reservoirs for Cytauxzoon spp.

Hepatozoon spp. are apicomplexan parasites that infect a wide variety of animals. The infection occurs through the ingestion of a hematophagous arthropod definitive host. Herein, we assessed the presence of Hepatozoon spp. in 165 captive wild felids and 100 captive wild canids using molecular techniques. We found that 6 felids (4 little spotted cats, 1 jaguarondi, and 1 puma) and 5 canids (2 bush dogs, 1 fox, 1 crab-eating fox, and 1 maned wolf) were positive for Hepatozoon spp. Hepatozoon spp. may be a potential pathogen and an opportunistic parasite in immunocompromised animals or if occurring in concomitant infections. Because most Brazilian wild felids and canids are endangered, knowing whether Hepatozoon infection represents a threat for these animals is crucial.

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Picobirnaviruses (PBVs) have recently been classified into the Picobirnaviridae family. They are small, non-enveloped viruses with bisegmented, double-stranded (ds) RNA genomes. Although they are found in the feces of a broad range of hosts, information regarding their genomes is limited to viruses detected from humans, rabbits, and porcine. Identification of PBVs has been done using PAGE and reverse transcription PCR (RT-PCR). In this study, we present a phylogenetic analysis of PBVs detected in the feces of dogs, snakes, and rats. In addition, we compare these strains to those from human and porcine hosts. To do so, 487 fecal specimens from dogs, snakes and rats were analyzed by PAGE. The positive specimens for PBV were tested by RT-PCR using primers for genogroup I of the PBVs. From the 11 genogroup I PBV samples, at least one from each host was sequenced and submitted for phylogenetic analysis. All of the sequences showed high homology with the human and porcine genogroup I PBV sequences. In this study we report the first detection of PBVs in snakes (8.5%). We also report a phylogenetic analysis that goes beyond humans and pigs to include dogs, rats, and snakes. However, more hosts must be included in the analysis so that we may reach better conclusions regarding the spread of these viruses.

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Ehrlichiosis, an emergent tick-borne disease that affects both humans and animals, may represent a threat to the survival and preservation of wild felids in Brazil. There are few studies of ehrlichiosis in wild felids in Brazil, but Ehrlichia spp. are present in domestic cats. Antibodies to Ehrlichia canis have been reported in a puma (Puma concolor). In this study we assessed the presence of these hemoparasites in the blood of Brazilian wild captive felids. Of the 72 animals tested, 5 (7%) were seropositive for the E. canis antigen, and 11 (15%) were positive for E. canis DNA sequences. We also performed sequence alignment to establish the identity of the parasite species infecting these animals using 16S rRNA and omp-1 genes. Sequences based on 16S rRNA were similar to those found in dogs and cats from Thailand, Brazil, China, and Taiwan and with E. canis obtained from a single individual (human) in Venezuela. Ehrlichia sp. sequence from sampled felines based on omp-1 gene was similar to the p28 and p30 multigene family of E. canis. To our knowledge, this is the first study of molecular detection of Ehrlichia sp. in Brazilian wild feline species.