دانلود رایگان مقاله انگلیسی کنترل بیولوژیکی خاکهای انتقال دهنده سرمی (STH) با استفاده از قارچ های ساپروفیت - الزویر 2018

ABSTRACT

Toxascaris leonina and Trichuris sp. are soil-transmitted helminths (STHs) infecting domestic and wild mammals. The antagonistic effect of the saprophytic filamentous fungi Mucor circinelloides and Verticillium sp. was examined on eggs of T. leonina passed in the feces of captive lynxes (Lynx lynx) kept in a zoological park. The activity of M. circinelloides and Trichoderma atrobrunneum was tested on eggs of Trichuris sp. shed by captive dromedaries (Camelus dromedarius). The parasiticide activity was assessed by measuring the ovistatic (delayed development) and ovicidal (non-viability) effects on eggs placed in Petri plates, and by spraying spores directly onto fecal samples. Based on the observation of that hyphae of M. circinelloides, Verticillium sp. and T. atrobrunneum adhered to the eggshells, penetrated and destroyed the inner embryo, an ovicidal type 3 effect was concluded. Development of eggs of T. leonina and Trichuris sp. in the feces was delayed in the presence of all fungi, and one third remained at the stage of zygote. A significant reduction of T. leonina viable eggs was recorded in the feces sprayed spores of M. circinelloides (58%) or Verticillium sp. (67%). Fifty percent of the eggs of Trichuris sp. became into non-viable by 30 days after the exposure to either M. circinelloides or T. atrobrunneum. It is concluded that distribution of the filamentous fungi M. circinelloides, Verticillium sp. and T. atrobrunneum constitutes a novel approach to conduct the biological control of the STHs (T. leonina and Trichuris sp.) affecting wild animals captive in a zoological park.

5. Conclusions

Proper preventive strategies are needed to support the control of STHs in animal species captive in zoological parks. Results obtained in the current research led us to conclude the usefulness of hand spraying spores of filamentous fungi as M. circinelloides, T. atrobrunneum or Verticillium sp. directly on feces of infected animals to reduce the viability of their eggs and/or their development to the infective stages. Moreover, spores should be also sprayed on the ground after the routine collection of feces from the plots, minimizing thus the risk of infection by soil transmitted helminths.