Related Experiment Videos
Strain variations within Eimeria meleagrimitis from the turkey
Abstract:
During the course of a field study of coccidiosis in turkeys, Eimeria oocysts were found which had much smaller dimensions that any previously recorded isolate from the turkey. These oocysts were purified by single oocyst infection of a turkey. The first oocysts (mean dimensions 16-15 X 14-75 micrometer) were recovered 103 h later. Inoculation of between 0-5 and 2-5 X 10(5) oocysts of this isolate caused severe effects on body weight gain. Cross-immunity studies showed the parasite to be a strain of E. meleagrimitis. Electrophoretic analyses of two enzymes showed that the strain could be differentiated from another strain of E. meleagrimitis (Weybridge strain B). The results show that strain variation occurs within the species E. meleagrimitis and extreme caution should be used in identifying species of Eimeria from the turkey by the oocyst characters.
Insights
A novel Eimeria oocyst strain in turkeys, smaller than previously recorded, caused significant weight gain issues. This finding highlights the importance of caution when identifying Eimeria species based solely on oocyst morphology.
Area of Science:
- Veterinary Parasitology
- Poultry Science
- Protozoology
Background:
- Coccidiosis is a significant disease in turkeys, caused by Eimeria species.
- Accurate identification of Eimeria species is crucial for effective disease management.
- Oocyst morphology is a primary characteristic used for Eimeria species identification.
Purpose of the Study:
- To characterize a newly discovered Eimeria oocyst isolate from turkeys with unusually small dimensions.
- To determine the pathogenicity and species identity of this novel isolate.
- To investigate potential strain variation within Eimeria meleagrimitis.
Main Methods:
- Isolation and purification of Eimeria oocysts via single oocyst infection in turkeys.
- Determination of oocyst dimensions and recovery time.
- Pathogenicity assessment through body weight gain studies post-inoculation.
- Cross-immunity assays to identify the parasite species.
- Electrophoretic analysis of enzyme profiles for strain differentiation.
Main Results:
- A novel Eimeria oocyst isolate with mean dimensions of 16.15 x 14.75 micrometers was identified.
- Inoculation with 0.5-2.5 x 10^5 oocysts resulted in severe negative effects on turkey body weight gain.
- Cross-immunity studies confirmed the isolate as a strain of Eimeria meleagrimitis.
- Electrophoretic analysis differentiated this strain from the Weybridge strain B of Eimeria meleagrimitis.
Conclusions:
- Significant strain variation exists within the Eimeria meleagrimitis species.
- Oocyst dimensions alone are insufficient for reliable Eimeria species identification in turkeys.
- Further research into Eimeria strain diversity and its implications for turkey health is warranted.