Anti-Pythium insidiosum activity of bioactive compounds from medicinal plants.

Pythiosis is a serious disease caused by the aquatic oomycete Pythium insidiosum that mainly affects mammals. Unlike fungal and bacterial resistance induced by the indiscriminate use of drugs, P. insidiosum has low susceptibility to antifungal drugs. In this sense, essential oils and their major components emerge as a promising treatment line for this disease. Given the above, this study sought to verify P. insidiosum (n = 34) susceptibility to the bioactive compounds eugenol, α-terpineol, menthol, and carvacrol and correlate them with the respective essential oils of Eugenia caryophyllata, Melaleuca alternifolia, Mentha piperita, and Origanum vulgare. The essential oils and bioactive compounds were purchased commercially and tested according to the Clinical and Laboratory Standards Institute protocol M38-A2. Our findings showed that eugenol, α-terpineol, and carvacrol had superior anti-P. insidiosum action than their respective essential oils, suggesting that they may be responsible for inhibitory activity against P. insidiosum. Notably, the major compound with the best anti-P. insidiosum activity was α-terpineol; nonetheless, menthol showed less activity than its essential oil. The results imply that essential oils and their major compounds may be important allies in treating pythiosis, expanding the perspectives of developing new drugs with anti-P. insidiosum activity.

Tremellomycetes isolated from organs of Columba livia.

Brain, lungs, and intestines of Columba livia captured in Brazil were analyzed for research on Tremellomycetes. Mycological culture presented the growth of colonies suggestive of Cryptococcus spp. in 11.60% (13/112) of the samples. Microscopy revealed capsulated yeast cells. Molecular analysis evidenced Papiliotrema flavescens, Naganishia diffluens, Filobasidium magnum, and Naganishia randhawae. Thermotolerance of Tremellomycetes isolates from brain and lung (n = 10) evidenced cell growth and viability at 37 °C. At 42 °C/24 h, these isolates showed viability, except for one P. flavescens isolate. Here, we report the first isolation of Tremellomycetes species from the brain and lungs of a healthy C. livia.

The study reported the first isolation of Tremellomycetes species, including P. flavescens, N. diffluens, F. magnum, and N. randhawae from the organs of domestic pigeons. All isolates expressed important virulence factors such as capsule and thermotolerance, indicating their pathogenic potential.

Effect of Paecilomyces lilacinus, Trichoderma harzianum and Trichoderma virens fungal extracts on the hatchability of Ancylostoma eggs / Efecto de los extractos de los hongos Paecilomyces lilacinus, Trichoderma harzianum y Trichoderma virens en la eclosionabilidad de huevos de Ancylostoma

Background. Ancylostoma species have demanded attention due to their zoonotic potential. The use of anthelmintics is the usual method to prevent environmental contamination by Ancylostoma eggs and larvae. Nematophagous fungi have been widely used in their biological control due to the fungus ability to capture and digest free nematode forms. Aims. The aim of this study was to evaluate the effect of four different fungal extracts of Paecilomyces lilacinus (n=2), Trichoderma harzianum (n=1) and Trichoderma virens (n=1) isolates on the hatchability of Ancylostoma eggs. Methods. Fungal extracts consisted of fungal broth culture supernatant without filtration (crude extract) and filtered broth (filtered extract), macerated mycelium (crude macerate), and macerated mycelium submitted to filtration (filtered macerate). The Ancylostoma eggs were obtained from the feces of naturally infected dogs. In vitro assays were performed in five replicates and consisted of four treatments and one control group. Results. The activity of the fungal extracts of each evaluated fungus differed (p<0.05) from those of the control group, showing significant ovicidal activity. The hatching of the eggs suffered reduction percentages of 68.43% and 47.05% with P. lilacinus, and 56.43% with T. harzianum, when crude macerate extract was used. The reduction with the macerate extract of T. virens was slightly lower (52.25%) than that for the filtered macerate (53.64%). Conclusions. The results showed that all extracts were effective in reducing the hatchability of Ancylostoma eggs. The ovicidal effect observed is likely to have been caused by the action of hydrolytic enzymes secreted by the fungi (AU)

Antecedentes. Las especies del género Ancylostoma son de gran importancia debido a su potencial zoonótico. El uso de antihelmínticos es el método habitual en la prevención de la contaminación ambiental por huevos y larvas del género Ancylostoma. Los hongos nematófagos se utilizan ampliamente en el control biológico de aquellos, debido a su capacidad de capturar y digerir nematodos libres. Objetivo. El objetivo del estudio fue evaluar el efecto de cuatro extractos diferentes de hongos (Paecilomyces lilacinus [n=2], Trichoderma harzianum [n=1] y Trichoderma virens [n=1]) en la eclosionabilidad de huevos de especies de Ancylostoma. Métodos. Los extractos de hongos constaban del sobrenadante del cultivo en caldo fúngico sin filtración (extracto crudo) y caldo filtrado (extracto filtrado), micelio macerado (macerado crudo) y micelio macerado sometido a filtración (macerado filtrado). Los huevos de Ancylostoma se obtuvieron a partir de heces de perros infectados de manera natural. Se realizaron cinco repeticiones de los ensayos in vitro con cuatro tratamientos y un grupo control. Resultados. La actividad de los extractos fúngicos de cada hongo evaluado difiere (p<0,05) de la de aquellos del grupo control, lo que demuestra una actividad ovicida significativa. Con el extracto crudo macerado, la reducción de la eclosión mostró porcentajes del 68,43 y el 47,05% en el caso de P. lilacinus y del 56,43% para el caso de T. harzianum. El porcentaje de reducción en el uso del macerado crudo en T. virens fue del 52,25%, algo inferior respecto al macerado filtrado (53,64%). Conclusiones. Los resultados mostraron que todos los extractos fueron eficaces en la reducción de la eclosionabilidad de huevos de Ancylostoma. Es probable que el efecto ovicida observado haya sido causado por la acción de enzimas hidrolíticas secretadas por los hongos (AU)

Trichoderma virens as a biocontrol of Toxocara canis: In vivo evaluation / Trichoderma virens como control biológico de Toxocara canis: evaluación in vivo

Background. Microorganisms have been widely studied as biological control agents of parasites of medical and veterinary importance. Coprophagous arthropods, bacteria and fungi are among the different organisms evaluated as potential biological control agents. Nematophagous fungi capture and digest the free forms of nematodes in the soil. Due to its zoonotic potential, Toxocara canis have been brought to the attention of researchers. Aims. The aim of the present study was to determine whether the administration of embryonated T. canis eggs exposed to the nematophagous fungus Trichoderma virens reduces parasite infection in experimental animals. Methods. Embryonated T. canis eggs were exposed to T. virens mycelium for 15 days at 25°C. Subsequently, 100 fungus-exposed eggs were orally administered to 20 Swiss mice. As a positive control, another 20 mice received 100 embryonated eggs that were not exposed to the fungus. After 48h, the animals were killed, and heart, lungs and liver were harvested for the recovery of larvae. Results. The organs of the animals that received embryonated T. canis eggs exposed to the fungus showed a lower mean larval recovery when compared with the animals that received embryonated eggs without fungus exposure (p<0.05). Conclusions. The exposure of T. canis eggs to T. virens reduces the experimental infection, demonstrating the potential of this nematophagous fungus as a biocontrol agent (AU)

Antecedentes. Algunos microorganismos han sido ampliamente estudiados como agentes de control biológico de parásitos de importancia médica y veterinaria. Los artrópodos coprófagos, las bacterias y los hongos están entre los diferentes organismos que sirven como agentes para el control con potencial biológico. Los hongos nematófagos capturan y digieren las formas libres de nematodos en el suelo. Toxocara canis, debido a su potencial zoonótico, ha captado la atención de los investigadores en estos estudios. Objetivos. El objetivo del presente estudio fue evaluar si la exposición de huevos embrionados de T. canis al hongo nematófago Trichoderma virens reduce la infección parasítica en un modelo experimental animal. Métodos. Los huevos embrionados de T. canis fueron expuestos al micelio de T. virens durante 15días a 25°C. Posteriormente, 100huevos de T. canis expuestos al hongo fueron administrados por vía oral a un grupo de 20ratones Swiss. Como control positivo se usó otro grupo de 20ratones que recibieron 100huevos embrionados no expuestos al hongo. Después de 48h, los animales fueron sacrificados y corazón, pulmones e hígado fueron extraídos para la posterior obtención de larvas. Resultados. El número de larvas obtenidas en los diferentes órganos fue menor en el grupo de animales que fueron infectados con los huevos embrionados de T. canis expuestos al hongo en comparación con el grupo de animales que recibieron huevos embrionados sin la exposición al hongo (p<0,05). Conclusiones. La exposición de los huevos de T. canis a T. virens reduce la infección experimental, lo que demuestra el potencial de este hongo nematófago como agente para el control biológico (AU)

In vitro reproduction of the life cycle of Pythium insidiosum from kunkers' equine and their role in the epidemiology of pythiosis.

Pythium insidiosum is an important pathogen of mammals' species, including humans. Equine is the main species affected by this oomycete. P. insidiosum requires an aquatic environment to develop its life cycle, and the susceptible hosts are contaminated when they contact the microorganism in swampy areas. The equine pythiosis is characterized by the formation of irregular masses within the cutaneous lesions, called kunkers, which easily detach from the lesion. From these structures, it is possible to isolate P. insidiosum in pure cultures. The present study aimed to reproduce in vitro the life cycle of P. insidiosum from kunkers of equine clinical lesions. Fifteen kunkers from different horses were tested. It was observed that the discharge of zoospores occurred after 24-48 h of incubation at 37 °C in, respectively, 40 and 47 % of the kunkers evaluated. Only two samples showed no development of the asexual cycle of P. insidiosum under the conditions tested. It was possible to demonstrate that kunkers are able to restart the asexual cycle of P. insidiosum. Based on our in vitro results, we highlight the importance of these structures in the epidemiology of the pythiosis, since kunkers can be a potential source of contamination of this oomycete for aquatic environments.