Publicação
New administration formula of parasiticide fungi spores to prevent infection by gastrointestinal nematodes in pasturing horses
| Resumo: | Anthelmintic resistance in horses has increased in recent years and the continuous search for alternative control methods has led to the development of complementary approaches such as biological control. This approach can make use of parasiticide fungi, such as Duddingtonia flagrans and Mucor circinelloides, in parasite population control and recent research has been focused on the development of new administration methods. Following this line of research, a new and alternative formula has been developed by using a lyophilized product that contained both D. flagrans and M. circinelloides spores for the control of gastrointestinal nematodes in horses. After the product manufacture and the normal spore morphology were assessed, these were tested for in vitro growth. A total of 20 Petri dishes were assembled with a mix of 0.1 g of product and 0.5 ml of water in solid media. The assembled plaques were kept at 25ºC in total darkness and all showed the development of new fungi spores after 10 days. Following the in vitro assessment, the product was administered per os to horses in order to observe their effect in the faecal egg count (FEC) of eggs per gram (EPG). Thus, one group of 5 horses in a pasture was chosen to receive 10 g of product (with M. circinelloides spores and a total of around 105 D. flagrans chlamydospores per horse), 3 days a week starting in September, and another group of 7 horses in an adjacent pasture remained as control. Following treatment with Ivermectin pour-on in September 2017, a faecal sample was collected from each horse on a monthly basis and FEC was assessed using a Modified McMaster technique. Only gastrointestinal nematode eggs, namely strongyle eggs, were observed with this technique. The EPG average from each group was compared for each individual month and overall to see the reduction effect achieved with the fungi treatment. Statistically significant differences were found between the two groups in February (72% reduction), March (64% reduction), and overall, 66% reduction. The horses in the test group only reached a cut-off value of 300 EPG two months after the horses in the control group. In November and January, faecal culture method was applied to all faecal samples, showing only the presence of cyathostomin larvae. This study allowed the successful development of a new formula for the administration of parasiticide fungi to horses, based on lyophilized product, which increases the possibilities for future product development and application. New and improved ways of biological control should be developed and implemented to increase parasite control and reduce anthelmintic resistance cases. |
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| Autores principais: | Evangelista, Francisco Miguel Dias |
| Assunto: | Parasite control biological control parasiticide fungi Duddingtonia flagrans Mucor circinelloides lyophilized product strongyles horses Controlo parasitário controlo biológico fungos parasiticidas produto liofilizado estrongilídeos cavalos |
| Ano: | 2018 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | Anthelmintic resistance in horses has increased in recent years and the continuous search for alternative control methods has led to the development of complementary approaches such as biological control. This approach can make use of parasiticide fungi, such as Duddingtonia flagrans and Mucor circinelloides, in parasite population control and recent research has been focused on the development of new administration methods. Following this line of research, a new and alternative formula has been developed by using a lyophilized product that contained both D. flagrans and M. circinelloides spores for the control of gastrointestinal nematodes in horses. After the product manufacture and the normal spore morphology were assessed, these were tested for in vitro growth. A total of 20 Petri dishes were assembled with a mix of 0.1 g of product and 0.5 ml of water in solid media. The assembled plaques were kept at 25ºC in total darkness and all showed the development of new fungi spores after 10 days. Following the in vitro assessment, the product was administered per os to horses in order to observe their effect in the faecal egg count (FEC) of eggs per gram (EPG). Thus, one group of 5 horses in a pasture was chosen to receive 10 g of product (with M. circinelloides spores and a total of around 105 D. flagrans chlamydospores per horse), 3 days a week starting in September, and another group of 7 horses in an adjacent pasture remained as control. Following treatment with Ivermectin pour-on in September 2017, a faecal sample was collected from each horse on a monthly basis and FEC was assessed using a Modified McMaster technique. Only gastrointestinal nematode eggs, namely strongyle eggs, were observed with this technique. The EPG average from each group was compared for each individual month and overall to see the reduction effect achieved with the fungi treatment. Statistically significant differences were found between the two groups in February (72% reduction), March (64% reduction), and overall, 66% reduction. The horses in the test group only reached a cut-off value of 300 EPG two months after the horses in the control group. In November and January, faecal culture method was applied to all faecal samples, showing only the presence of cyathostomin larvae. This study allowed the successful development of a new formula for the administration of parasiticide fungi to horses, based on lyophilized product, which increases the possibilities for future product development and application. New and improved ways of biological control should be developed and implemented to increase parasite control and reduce anthelmintic resistance cases. |
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