Biological control of Fasciola hepatica eggs with the Pochonia chlamydosporia fungus after passing through the cattle gastrointestinal tract.

Fasciolosis is a disease caused by Fasciola hepatica responsible for causing significant losses in livestock. This study aimed to evaluate the Pochonia chlamydosporia fungus (isolate VC1) on F. hepatica eggs after passing through the cattle gastrointestinal tract. For this evaluation, 1 g pellet was given in sodium alginate matrix per kilogram live weight containing 25% of fungal mycelium from isolate VC1 per animal. Twelve animals were used, six treated and six untreated (control). Some stool samples were collected from the groups of treated and control animals, at the times of 12, 18, 24, 48, 72, and 96 h after the pellets' administration. Then, from each stool sample of treated and control groups, 2 g was placed in a Petri dish of 9 cm in diameter, containing 2% water-agar and 1,000 eggs of F. hepatica. It was observed that the fungus was effective in preying upon the eggs in the samples recovered at all of the schedules starting at 12 h. Furthermore, differences were observed (p < 0.01) in the destruction of eggs in the Petri dishes in the treated group compared with the control group. The ovicidal effect was observed after 7 days of interaction. The ovicidal P. chlamydosporia fungus was effective in destroying F. hepatica eggs; therefore, it is suggested that this fungus could be employed as agent for the control of helminth eggs.

Resistance of different fungal structures of Duddingtonia flagrans to the digestive process and predatory ability on larvae of Haemonchus contortus and Strongyloides papillosus in goat feces.

The dynamics of the passage of conidia, chlamydospores, and mycelia of the fungus Duddingtonia flagrans through the digestive tracts of goats was evaluated. Four groups with five goats each were formed. In the group conidia, each animal received 1 x 10(6) D. flagrans conidia per kilogram of live weight. In the group chlamydospore, each animal received 1 x 10(6) chlamydospores per kilogram of live weight. In the group mycelia, each animal received 1 g of mycelium mass per kilogram of live weight. In the control group, the animals received no fungal structure. Feces were obtained 3 h before and 12, 24, 30, 36, 42, 48, 60, 72, 84, and 96 h after the inoculation. The feces were placed in Petri dishes containing water-agar. The Petri dishes were examined to detect the fungus and trapped nematodes. A second trial evaluated the effect of the fungal structures on the number of gastrointestinal larvae of Haemonchus contortus and Strongyloides papillosus harvested from the fecal cultures of the goats. The feces were obtained from the goats in the 12-24, 24-30, 30-36, 42-48, 60-72, 72-84, and 84-96 intervals after the inoculation. D. flagrans survived the digestive process of the goats and maintained its predatory activity, being observed from 12 to 96 h before inoculation in the animals that received chlamydospores and conidia.

[The relationship between larvae recovered of pasture and counting eggs per grams of feces (epg) of the gastrointestinal nematodes of cattle in the Microrregion of Viçosa, State of Minas Gerais]. / Relação entre larvas recuperadas da pastagem e contagem de ovos por gramas de fezes (opg) de nematóides gastrintestinais de bovinos na Microrregião de Viçosa, Minas Gerais.

Eight calves with one year old approximately, Holstein-zebu cross-breeding, were stocked in paddock to analysis the relation between the eggs per grams of feces (EPG) and larvae number recovered of pastures, from February to September 2005, at municipality of Viçosa, Zona da Mata region, State of Minas Gerais, Brazil. During this time, feces and pastures were collected for examination of EPG and larvae recovered from pastures, respectively. The genera Cooperia, Haemonchus and Oesophagostomum larvae were harvested in paddock until 20 centimeters and between 20 and 40 cm far distance of fecal cake. The genus Cooperia (60.97%) was the most prevalent in the pastures. In coprocultures, Haemonchus (42.65%) was the most prevalent genus of nematode. The coefficient of correlation of the larvae recovered of pasture and the EPG was not significant (P < 0.05). It can indicate that this relation can be influenced possibly by several factors related on the nematodes, the host and the climate conditions.