The role of the American cockroach (Periplaneta americana) as transport host of Eimeria tenella to chickens.

The role of the American cockroach, Periplaneta americana as transport host for Eimeria tenella was evaluated. Twenty-four cockroaches were orally fed with sporulated oocysts of E. tenella. Their feces and digestive tract were examined for oocysts by sugar centrifugal flotation technique and PCR. Infectivity of the oocysts recovered from the digestive tract of infected cockroaches as well as from their feces was evaluated by orally inoculating them into Boris Brown chickens. E. tenella oocysts were found in the digestive tract and feces of infected cockroaches up to day 4 after ingestion of oocysts. Furthermore, oocysts that were recovered from the digestive tract and feces of cockroaches remained infective for 4 and 3 days after ingestion of oocysts, respectively. Presence of oocysts in the feces of chicken that had been inoculated with either digestive tract or feces of P. americana demonstrated the infectivity of E. tenella oocysts from digestive tract or feces, suggesting that P. americana may play a role in the transmission of E. tenella among chicken and between chicken flocks.

Eimeria tenella oocyst excretion and riboflavin supplement in infected chicken.

The effect of riboflavin supplement in Eimeria tenella-infected chickens was evaluated. Mortality, fecal consistency, and oocysts per gram of feces were monitored for groups of E. tenella-infected chickens administered a basal diet supplemented with either riboflavin, the anti-coccidial drug amprolium, or with both compounds. The number of oocysts shed per chicken in the riboflavin-treated group was significantly higher than the positive non-treated control group. No significant difference in oocyst number between the amprolium-treated group and riboflavin plus amprolium-treated group was observed. Thus, the addition of 0.8 g/kg of riboflavin to basal diet can increase oocyst number in E. tenella-infected chicken, but has no effect on the efficacy of amprolium.

Dynamics of liver enzymes in rabbits experimentally infected with Fasciola sp. (Intermediate form from Japan).

Dynamics of serum liver enzymes in rabbits experimentally infected with metacercariae of Fasciola sp. (intermediate form between Fasciola hepatica and F. gigantica) were monitored. Gradual increase of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were observed from 3 weeks post-inoculation (WPI) and peaked at 6 WPI, which corresponded well to the period of migration and development of juvenile fluke in the liver parenchyma and the time when the young adult flukes migrated to the bile duct. However, no significant increase in serum gamma-glutamyl transferase (GGT) and alkaline phosphatase (ALP) were observed. This could reflect reduced or minimal injury of bile ducts and biliary epithelia as the flukes had reached the adult stage. Alpha- fetoprotein (AFP) and carcinoembryonic antigen (CEA) were not detected in the infected rabbit during the course of the experiment. Serum liver enzymes monitoring might be useful for understanding the host-parasite relationship in fascioliasis.