Effect of the nematophagous fungus, Duddingtonia flagrans, on the larval development of goat parasitic nematodes: a plot study

Abstract

-Effective alternatives to anthelmintic treatment against nematode parasites of goats are required because of the high prevalence of benzimidazole resistance. Towards this objective, the nematophagous fungus, Duddingtonia flagrans (Df), was used in a plot study against two main parasitic nematode species of goats, Teladorsagia circumcincta (Tcir) and Trichostrongylus colubriformis (Tcol). Worm-free, culled goats were experimentally infected with strains of Tcir and Tcol to constitute donors. Half of the animals were periodically given Df chlamydospores at a daily dose of 2.5 × 10 5 spores/kg BW while the remaining animals were kept as controls. At 5 time periods i.e. March, May, July, September and November 2001, corresponding to the main grazing season in France for goats, faeces were collected from the 6th day of fungus administration for the following 2 days to obtain approximately 1 kg of faeces from each group of animals: Tcir/Control, Tcol/Control, Tcir/Fungus, Tcol/Fungus. For each period and each group, the faeces were deposited on a 1 m 2 grass plot and the grass was cut (3 replicates) on weeks 2, 4, 6, 8 ,12 after deposition, for infective larval recovery. Larvae were counted and the results were expressed as a ratio of larvae/ eggs deposited. On the plots with the control faeces deposited in March, July and September, the grass infectivity due to Tcir and Tcol was similar and the maximum number occurred between 2 and 4 weeks post deposition. In May, the maximum numbers of larvae were not recorded until 8 weeks after deposition, due to high daily temperatures and dryness. In November, larval development took place only for Tcir. On the plots with the fungus treated faeces, a significant reduction in grass infectivity occurred for both nematodes and ranged from 50-60% in May, July and November deposits to 80-90% in the September deposit. On the contrary to these findings, no difference was recorded between the fungus and control plots for the March deposit. In conclusion, D. flagrans is suitable for reducing the number of infective larvae in the herbage during the main part of the grazing period for the most important digestive nematodes of goats.goat / biological control / Duddingtonia flagrans / nematode parasite

Effect of nematophagous fungusDuddingtonia flagransand energy supplementation on the epidemiology of naturally infected kids

“…Previous results have demonstrated that the nematode destroying effects of fungi on Trichostrongylidae parasites in faecal cultures [1,11,19] may be reflected in reduced pasture contamination under field grazing conditions [27]. However, the results herein showed that GI nematode species were affected differently by treatment.…”

Administration of Duddingtonia flagrans chlamydospores to goats to control gastro-intestinal nematodes: dose trials

“…Paraud and Chartier [17] and Paraud et al [18] reported reductions higher than 80% of the larval development of Teladorsagia circumcincta or Trichostrongylus colubriformis after the administration of 5 × 10 5 chlamydospores/ kg BW/day when compared to the control. In the same way, in a plot study, after the administration of chlamydospores at a dose rate of 2.5 × 10 5 /kg BW/day to goats, Chartier and Pors [4] showed reductions in larval numbers of T. circumcincta or T. colubriformis ranging from 50 to 93% compared to the control according to the month of faecal deposit on the pasture.…”

“…In goats, preliminary studies have shown that D. flagrans is able to reduce the number of larvae in coproculture of two of the predominant nematode species in France, Teladorsagia circumcincta and Trichostrongylus colubriformis by more than 80% in experimental studies [17,18] and from 50 to 80% in a plot study [4]. Similarly, Terrill et al [23] in the southeastern United States and Chandrawathani et al [2] in Malaysia have demonstrated the capability of D. flagrans to limit the number of Haemonchus contortus infective larvae in faecal cultures in tropical conditions when varying the chlamydospore dose rates or fungal delivery systems.…”

Comparative efficacy of the nematode-trapping fungus Duddingtonia flagrans against Haemonchus contortus, Teladorsagia circumcincta and Trichostrongylus colubriformis in goat faeces: influence of the duration and of the temperature of coproculture

“…This latter option is based on the administration of chlamydospores of the predacious fungus, Duddingtonia flagrans, in animal food, which leads to a reduction of the pre-parasitic stages of gastro-intestinal nematodes in the faeces as assessed in several herbivorous species (Larsen 2000). In goats, the efficacy of D. flagrans has been demonstrated against the main digestive nematode species occurring in France, Teladorsagia circumcincta and Trichostrongylus colubriformis, in experimental and in plot studies as well (Chartier and Pors 2003;Paraud and Chartier 2003;Paraud et al 2004). These results have been confirmed more recently in mixed natural infections including Haemonchus contortus species (Paraud et al 2005).…”