In vitro and in vivo studies of nematophagous fungi Arthrobotrys musiformis and Arthrobotrys robusta against the larvae of the trichostrongylides.

Six isolates of Arthrobotrys musiformis and five isolates of Arthrobotrys robusta were assessed in in vitro test regarding the capacity of prey larvae of the natural mixed trichostrongylides. In 5 isolates of A. robusta, the decrease percentage of infective larvae (L3) of trichostrongylides ranged from 97.71%-99.98% and for the isolates of A. musiformis, 5 isolates ranged from 97.99%-99.95% and only NF015 isolate 60.72%. In the following, the isolate (NPS045) of A. musiformis was selected to assess its excretion time in feces after oral administration of goats. Regarding L3 reduction rate, results demonstrated by NPS045 at each time point after fungal administration were 31.65% (12 h), 51.25% (24 h), 41.07% (48 h), 6.44% (72 h), 0% (96 h) and (120 h) (p<0.05) respectively, when compared to the control group. In the plates of the treated groups, the presence of the isolate (NPS045) was detected in samples at 12, 24 and 48 h after the fungus dose and 72 h later was not done. All native isolates of nematophagous fungi, including 6 isolates of A. musiformis and 5 isolates of A. robusta were assessed in vivo regarding the capacity of supporting the passage through goat gastrointestinal tract. The 3 isolates of A. musiformis could be able to pass through the digestive tract of goats without complete loss of ability of preying larvae of trichostrongylides in feces and their efficacies ranged from 47.60% to 55.93%. The two isolates of A. robusta survived the passage and the percentage reduction of L3 in feces were 41.96% and 66.97%, respectively. The remaining isolates were negative for both the efficacy of L3 reduction and the fungal examination in feces. In this study, the native isolates whose efficacies are good in vivo test have preliminarily demonstrated to be potential for the biological control of small ruminant parasite.