Control of Strongyloides westeri by nematophagous fungi after passage through the gastrointestinal tract of donkeys.

Strongyloides westeri is the most prevalent nematode among equines aged up to four months and causes gastrointestinal disorders. The objective of this study was to observe the control of infective S. westeri larvae (L3) by the nematophagous fungi Duddingtonia flagrans (AC001) and Monacrosporium thaumasium (NF34) after passage through the gastrointestinal tract of female donkeys. Twelve dewormed female donkeys that were kept in stables were used. Two treatment groups each comprising four animals received orally 100 g of pellets made of sodium alginate matrix containing a mycelial mass of either D. flagrans (AC001) or M. thaumasium (NF34). The control group consisted of four animals that received pellets without fungus. Feces samples were then collected from the animal groups at different times (after 12, 24, 48 and 72 hours). These feces were placed in Petri dishes containing 2% water-agar medium and 1000 L3 of S. westeri. AC001 and NF34 isolates showed the ability to destroy the L3, after gastrointestinal transit, thus demonstrating their viability and predatory activity.

[Destruction of Strongyloides venezuelensis infective larvae by fungi Duddingtonia flagrans, Arthrobotrys robusta and Monacrosporium sinense]. / Destruição de larvas infectantes de Strongyloides venezuelensis pelos fungos Duddingtonia flagrans, Arthrobotrys robusta e Monacrosporium sinense.

INTRODUCTION: Strongyloides venezuelensis has been used as a model for studying human strongyloidosis. METHODS: This study aimed to compare the ability of predatory nematophagous fungi Duddingtonia flagrans (AC001), Arthrobotrys robusta (I-31) and Monacrosporium sinense (SF53) and on infective larvae (L3) of Strongyloides venezuelensis in laboratory conditions on 2% water-agar medium. RESULTS: At the end of the experiment, the percentage reductions of Strongyloides venezuelensi L3 were: 93% (AC001), 77.2% (I-31) and 65.2% (SF53). CONCLUSIONS: The nematophagous fungi were able to capture and destroy the L3 in vitro and can be used as biological controllers of Strongyloides venezuelensi.

Destruição de larvas infectantes de Strongyloides venezuelensis pelos fungos Duddingtonia flagrans, Arthrobotrys robusta e Monacrosporium sinense / Destruction of Strongyloides venezuelensis infective larvae by fungi Duddingtonia flagrans, Arthrobotrys robusta and Monacrosporium sinense

INTRODUÇÃO: Strongyloides venezuelensis tem sido utilizado como um modelo para estudo da estrongiloidose humana. MÉTODOS: O objetivo deste trabalho foi comparar a capacidade predatória dos fungos nematófagos Duddingtonia flagrans (AC001), Arthrobotrys robusta (I-31) e Monacrosporium sinense (SF53) sobre larvas infectantes (L3) de Strongyloides venezuelensis em condições laboratoriais no meio ágar-água 2 por cento. RESULTADOS: Ao final do experimento, os percentuais de redução de L3 de Strongyloides venezuelensis observados foram de: 93 por cento (AC001); 77,2 por cento (I-31) e 65,2 por cento (SF53). CONCLUSÕES: Os fungos nematófagos foram capazes de capturar e destruir in vitro as L3, podendo ser utilizados como controladores biológicos de Strongyloides venezuelensis.

INTRODUCTION: Strongyloides venezuelensis has been used as a model for studying human strongyloidosis. METHODS: This study aimed to compare the ability of predatory nematophagous fungi Duddingtonia flagrans (AC001), Arthrobotrys robusta (I-31) and Monacrosporium sinense (SF53) and on infective larvae (L3) of Strongyloides venezuelensis in laboratory conditions on 2 percent water-agar medium. RESULTS: At the end of the experiment, the percentage reductions of Strongyloides venezuelensi L3 were: 93 percent (AC001), 77.2 percent (I-31) and 65.2 percent (SF53). CONCLUSIONS: The nematophagous fungi were able to capture and destroy the L3 in vitro and can be used as biological controllers of Strongyloides venezuelensi.

In vitro predatory activity of nematophagous fungi and after passing through gastrointestinal tract of equine on infective larvae of Strongyloides westeri.

Three isolates of predator fungi Duddingtonia flagrans (AC001), Monacrosporium thaumasium (NF34), and Arthrobotrys robusta (I-31) were assessed in in vitro test regarding the capacity of prey infective larvae (L(3)) Strongyloides westeri. Compared to control, without fungus, there was a significant decrease (P < 0.01) of 80.4%, 67.9%, and 72.8% in means of infective larvae S. westeri recovered from treatments with isolates AC001, NF34, and I-31, respectively. All tested isolates were efficient in the capture of S. westeri (P > 0.01) in vitro test. Linear regression coefficients of treated and control groups were -0.21 for control, -0.32 for D. flagrans, -0.34 for M. thaumasium, and -0.22 for A. robusta. In the following, isolates AC001 and NF34 were assessed in vivo regarding the capacity of supporting the passage through equine gastrointestinal tract without loss of ability of preying infective larvae S. westeri. Fungal isolates survived the passage and were efficient in preying L(3) since the first 12 h of collection (P < 0.01) in relation to the control group (without fungus). Compared to control, there was a significant decrease (P < 0.01) of 76.4% and 76.7% (12 h), 86.4% and 85.9% (24 h), 88.3% and 87.7% (48 h), and 89.9% and 87.2% (72 h) in means of infective larvae S. westeri recovered from treatments with isolates AC001 and NF34, respectively. Linear regression coefficients of L(3) of recovered S. westeri regarding the collections due to time were 1.93 for control, -3.52 for AC001, and -2.64 for NF34. Fungi D. flagrans and M. thaumasium (NF34) have demonstrated to be promising for use in the biological control of equine parasite S. westeri.

Resistance of different fungal structures of Duddingtonia flagrans to the digestive process and predatory ability on larvae of Haemonchus contortus and Strongyloides papillosus in goat feces.

The dynamics of the passage of conidia, chlamydospores, and mycelia of the fungus Duddingtonia flagrans through the digestive tracts of goats was evaluated. Four groups with five goats each were formed. In the group conidia, each animal received 1 x 10(6) D. flagrans conidia per kilogram of live weight. In the group chlamydospore, each animal received 1 x 10(6) chlamydospores per kilogram of live weight. In the group mycelia, each animal received 1 g of mycelium mass per kilogram of live weight. In the control group, the animals received no fungal structure. Feces were obtained 3 h before and 12, 24, 30, 36, 42, 48, 60, 72, 84, and 96 h after the inoculation. The feces were placed in Petri dishes containing water-agar. The Petri dishes were examined to detect the fungus and trapped nematodes. A second trial evaluated the effect of the fungal structures on the number of gastrointestinal larvae of Haemonchus contortus and Strongyloides papillosus harvested from the fecal cultures of the goats. The feces were obtained from the goats in the 12-24, 24-30, 30-36, 42-48, 60-72, 72-84, and 84-96 intervals after the inoculation. D. flagrans survived the digestive process of the goats and maintained its predatory activity, being observed from 12 to 96 h before inoculation in the animals that received chlamydospores and conidia.

The control of the free-living stages of Strongyloides papillosus by the nematophagous fungus, Arthrobotrys oligospora.

Two laboratory trials were conducted to determine the effect of the addition of spores (conidia) of the nematophagous fungus, Arthrobotrys oligospora, on the development of the ruminant parasite, Strongyloides papillosus, in cultures of bovine faeces. Both studies showed that at a concentration of 2000 conidia/g faeces virtually eliminated infective larvae (> 99% reduction), following 14 days incubation under ideal conditions (25 degrees C and saturated humidity) for free-living development of this parasite species. In one trial, a high level of control was also observed at a 10-fold decrease in conidia concentration (200 spores/g faeces). This work has demonstrated, in principle, that A. oligospora could provide a practical biological control agent against S. papillosus infecting intensively raised young ruminants in the humid tropics/subtropics.