Manoel Eduardo da Silva

Control of infective larvae of gastrointestinal nematodes in heifers using different isolates of nematophagous fungi.

The effect of different nematophagous fungi [Duddingtonia flagrans (AC001 and CG722) and Monacrosporium thaumasium (NF34)] with regard to controlling infective larvae (L3) of nematodes after gastrointestinal transit in female cattle (3/4 Holstein × Zebu) was evaluated. A total of 24 pubescent female cattle were used, weighing approximately 320 kg each one. There were three treatment groups, each contained six animals that received 150 g of pellets (0.2 g of mycelium), orally in a single dose, in a sodium alginate matrix containing mycelial mass of the fungus D. flagrans (AC001 or CG722) or M. thaumasium (NF34); and one control group (without fungi). Fecal samples were collected from the animals at intervals of 12, 15, 18, 21, 24, 48, and 72 hours. At the end of 17 days, the L3 not subjected to predation were recovered by means of the Baermann method. The fungal isolates tested were capable of destroying the L3 after gastrointestinal transit. It was observed that within 72 hours, the isolates AC001, CG722, and NF34 showed a higher predatory activity (81.2%, 97.3%, and 98.3%, respectively). The results justify the need for studies in the field, and over longer intervals, in order to observe the efficiency of the fungus D. flagrans, or even M. thaumasium, for environmental control over nematodes in naturally infected cattle.

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.

Fungal Antagonism Assessment of Predatory Species and Producers Metabolites and Their Effectiveness on Haemonchus contortus Infective Larvae.

The objective of this study was to assess antagonism of nematophagous fungi and species producers metabolites and their effectiveness on Haemonchus contortus infective larvae (L3). Assay A assesses the synergistic, additive, or antagonistic effect on the production of spores of fungal isolates of the species Duddingtonia flagrans, Clonostachys rosea, Trichoderma esau, and Arthrobotrys musiformis; Assay B evaluates in vitro the effect of intercropping of these isolates grown in 2% water-agar (2% WA) on L3 of H. contortus. D. flagrans (Assay A) produced 5.3 × 106 spores and associated with T. esau, A. musiformis, or C. rosea reduced its production by 60.37, 45.28, and 49.05%, respectively. T. esau produced 7.9 × 107 conidia and associated with D. flagrans, A. musiformis, or C. rosea reduced its production by 39.24, 82.27, and 96.96%, respectively. A. musiformis produced 7.3 × 109 spores and associated with D. flagrans, T. esau, or C. rosea reduced its production by 99.98, 99.99, and 99.98%, respectively. C. rosea produced 7.3 × 108 conidia and associated with D. flagrans, T. esau, or A. musiformis reduced its production by 95.20, 96.84, and 93.56%, respectively. These results show evidence of antagonism in the production of spores between predators fungi.

Efficacy of Clonostachys rosea and Duddingtonia flagrans in Reducing the Haemonchus contortus Infective Larvae

The biocontrol is proven effective in reducing in vitro and in situ free-living stages of major gastrointestinal helminths, allowing progress in reducing losses by parasitism, maximizing production, and productivity. This study aimed at evaluating the predatory activity of fungal isolates of Duddingtonia flagrans and Clonostachys rosea species and its association on infective larvae (L3) of H. contortus in microplots formed by grasses and maintained in a protected environment. All groups were added with 10 mL of an aqueous suspension with 618 H. contortus L3 approximately. Group 1 was used as control and only received the infective larvae. Groups 2 and 3 received D. flagrans chlamydospores and C. rosea conidia at doses of 5 × 106. Group 4 received the combination of 5 × 106 D. flagrans chlamydospores + 5 × 106 C. rosea conidia. D. flagrans and C. rosea showed nematicidal effectiveness reducing by 91.5 and 88.9%, respectively, the population of H. contortus L3. However, when used in combination efficiency decreased to 74.5% predation of H. contortus L3. These results demonstrate the need for further studies to determine the existence of additive effects, synergistic or antagonistic, between these species.

Canine Leishmaniasis: An Overview of the Current Status and Strategies for Control

Canine leishmaniasis (CanL) is a vector-borne disease caused by Leishmania infantum and is transmitted by female phlebotomine sand flies primarily between animals and secondarily to humans. The course of infection may be different from one individual dog to another, ranging from spontaneous cure to acute evolution that leads to death, if proper management and therapy are not adopted. A parasitological cure is rarely achieved and clinical recurrences in CanL are frequent. Vaccination associated with the use of topical insecticides is undoubtedly the most effective form of prevention and control of the disease. In order to integrate the most important scientific knowledge of the literature in one objective publication, this review proposes a short overview of the main points of CanL.

Produção de conídios e clamidósporos de Dunddingtonia flagrans e Monacrosporium thaumasium em diferentes meios sólidos

Las especies Duddingtonia flagrans y Monacrosporium thaumasium son micro-hongos considerados promisorios agentes del control biologico de parasitos. Bajo condiciones adversas como la falta de nutrientes, estos hongos producen esporas capaces de sobrevivieren despues de pasar por el tracto gastrointestinal de los animales. La formacion de estas estructuras es una caracteristica deseable ya que promueve la sobrevivencia y la diseminacion de los hongos para propositos de biocontrol. El objetivo de este estudio fue evaluar la produccion de esporas de dos especies de hongos nematofagos D. flagrans (aislados AC001 y CG722) y M. thaumasium (NF34A). Estos fueron cultivados en los subproductos agroindustriales, que tenian el intento de identificar el mejor medio para uso en programas de biocontrol de nematodos. Diferentes volumenes (10, 15 y 20 mL) de masa micelial fueron utilizados como inoculos iniciales y adicionados a 100 gramos de medios de crecimientos solidos (semola de arroz - QA; semola de maiz - QM; bagazo de cana - BC; paja de arroz - PA y cascara de cafe - CC) y mantenidos a 25°C en la obscuridad para evaluar la produccion de esporas. Los aislados AC001 y CG722 mostraron las mejores producciones en el medio de la QA (p<0,05). El volumen de 20 mL de masa micelial utilizado como inoculo inicial proporciono una mayor recuperacion de esporas. El aislado NF34A presento una baja o nula produccion de estructuras reproductivas en los diferentes volumenes y medios de crecimientos utilizados. La mejor produccion de esporas se obtuvo utilizando subproductos de la agroindustria con mayor densidad proteica y energetica.