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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Strongyloidiasis is a parasitic neglected disease caused by the nematode Strongyloides stercoralis affecting 30 to 100 million people worldwide. Complications, strongly associated with alcoholism, organ transplants, and HTLV-1 virus, often arise due to late diagnosis, frequently leading to patient death. Lack of preemptive diagnosis is not the only difficulty when dealing with this parasite, since there are no gold standard diagnostic techniques, and the ones used have problems associated with sensitivity, resulting in false negatives. Treatment is also an issue as ivermectin and benzimidazoles administration leads to inconsistent cure rates and several side effects. Researching new anti-Strongyloides drugs is a difficult task since S. stercoralis does not develop until the adult stages in Mus musculus (with the exception of SCID mice), the main experimental host model. Fortunately, alternative parasite models can be used, namely, Strongyloides ratti and S. venezuelensis. However, even with these models, there are other complications in finding new drugs, which are associated with specific in vitro assay protocol steps, such as larvae decontamination. In this review, we highlight the challenges associated with new drug search, the compounds tested, and a list of published in vitro assay methodologies. We also point out advances being made in strongyloidiasis diagnosis so far.

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.