The biosynthesis of metallic nanoparticles (NPs) using biological systems such as fungi has evolved to become an important area of nanobiotechnology. Herein, we report for the first time the extracellular synthesis of highly stable silver NPs (AgNPs) using the nematophagous fungus Duddingtonia flagrans (AC001). The fungal cell-free filtrate was analyzed by the Bradford method and 3,5-dinitrosalicylic acid assay and used to synthesize the AgNPs in the presence of a 1 mM AgNO₃ solution. They have been characterized by UV–Vis spectroscopy, X-ray diffraction, transmission electron microscopy, dynamic light scattering, Zeta potential measurements, Fourier-transform infrared, and Raman spectroscopes. UV–Vis spectroscopy confirmed bioreduction, while X-ray diffractometry established the crystalline nature of the AgNPs. Dynamic light scattering and transmission electron microscopy images showed approximately 11, 38 nm monodisperse and quasispherical AgNPs. Zeta potential analysis was able to show a considerable stability of AgNPs. The N–H stretches in Fourier-transform infrared spectroscopy indicate the presence of protein molecules. The Raman bands suggest that chitinase was involved in the growth and stabilization of AgNPs, through the coating of the particles. Our results show that the NPs we synthesized have good stability, high yield, and monodispersion.

Background: Helminth parasites cause morbidity and mortality in both humans and animals. Most anthelmintic drugs used in the treatment of parasitic nematode infections act on target proteins or regulate the electrical activity of neurons and muscles. In this way, it can lead to paralysis, starvation, immune attack, and expulsion of the worm. However, current anthelmintics have some limitations that include a limited spectrum of activity across species and the threat of drug resistance, which highlights the need for new drugs for human and veterinary medicine. Purpose: Present study has been conducted to determine the anthelmintic activity of silver nanoparticles (AgNPs) synthesized from the extract of nematophagous fungus, Duddingtonia flagrans, on the infecting larvae of Ancylostoma caninum (L₃). Methods: The nanoparticles were characterized by visual, ultraviolet, Fourier-transform infrared spectroscopy, transmission electron microscopy (TEM) analysis, and X-ray diffraction. The in vitro study was based on experiments to inhibit the motility of infective larvae (L3), and the ultrastructural analysis of the nematode was performed by images obtained by TEM. Results: The XRD studies revealed the crystalline nature of the nanoparticles, and FTIR results implied that AgNPs were successfully synthesized and capped with compounds present in the extract. The results showed that the green synthesis of AgNPs exhibited nematicidal activity, being the only ones capable of penetrating the cuticle of the larvae, causing changes in the tegmentum, and consequently, the death of the nematode. Conclusion: The extract of the fungus D. flagrans is able to synthesize AgNP and these have a nematicidal action.

This study compared the coadministration among the three nematode predatory fungi, Duddingtonia flagrans, Monacrosporium thaumasium, and Arthrobotrys robusta, in the biological control of cattle gastrointestinal nematodiasis in comparison with the use of the fungus D. flagrans alone. Five groups consisting of eight Girolando heifers were kept in paddocks of Brachiaria decumbens for six months. Each heifer received 1 g/10 kg of pellets containing the fungi (0.2 g of fungus/10 kg b.w.). Group 1 (G1) received pellets with D. flagrans and M. thaumasium in coadministration, G2 received D. flagrans and A. robusta, G3 received M. thaumasium, A. robusta, and D. flagrans, and G4 received the fungus D. flagrans alone. Group 5 (control) received pellets without fungi. The monthly mean of fecal egg count (FEC) of Groups 1, 2, 3, and 4 were 93.8, 85.3, 82.7, and 96.4% smaller than the mean of control group. The treatments with pellets containing D. flagrans or D. flagrans + M. thaumasium produced significantly better results than the D. flagrans + A. robusta or the combination of the three fungi. The associations which include A. robusta were less efficient in this study than D. flagrans alone or associated with M. thaumasium.

Prosthenorchis elegans is an acanthocephalan intestinal parasite reported in neotropical primates. Despite parasitism by P. elegans having already been described in wild marmosets in the Brazilian Atlantic Forest, there are no reports of this infection in wild Geoffroy’s marmoset (Callithrix geofroyi). The aim of this study is to report one case of P. elegans parasitism in a free-ranging C. geoffroyi from Brazilian Atlantic Forest in Espírito Santo state, and characterize the pathological and parasitological findings of this infection. One Geoffroy’s marmoset necropsied at the Vila Velha University’s Veterinary Pathology Laboratory presented intense chronic transmural ulcerative enteritis associated with twenty cylindrical helminths present in the jejunum and ileum. We can conclude that parasitism by P. elegans occurs in free-ranging groups of Geoffroy’s marmosets. Its infection produced severe intestinal lesions even in free-ranging marmoset and therefore is a threat to this animal’s survival in wildlife and can have some impact on primate conservation in the Brazilian Atlantic Forest.

This study aimed to evaluate the efficacy of the association of the nematophagous fungi (Duddingtonia flagrans-AC001); (Pochonia chlamydosporia-VC4) and (Arthrobotrys robusta-I31) in a pelletised formulation of a sodium alginate matrix. The viability and activity of pellet germination and fungal activity (after encapsulation) were evaluated using in vitro and in vivo tests. Next, 12 heads of cattle, Dutch mestizo x zebu, with an average age of 12 months were dewormed with an anthelmintic. Next, 20 days after treatment with the anthelmintic, the animals were randomly divided into two groups of six animals each, and placed in two paddocks with 7.0 ha each of Brachiaria decumbens with historical grazing by animals naturally infected by gastrointestinal nematode parasites. At first, each animal was treated with 2 g of pellets per 10 kg of animal, containing the associated fungi (AC001 + VC4 + I31) administered twice a week in conjunction with commercial feed. Each animal in the control group received 2 g of pellets without mycelia added to the feed. The percentage reduction of infective larvae in the in vitro test was 94% (p < .01). In the in vivo test, the treated animals with fungal association had lower egg counts per gram of faeces (p < .01) compared to the control group animals – a reduction of 91.8%. The reduction in the number of infective larvae recovered from the pasture was 27.5% at a distance of 0–20 cm from the stool bulk, and 26.7% at a distance of 20–40 cm. This association (AC001 + VC4 + I31) of nematophagous fungi was effective in nematode control.