Intraspecific polymorphisms of Eimeria species due to resistance against anticoccidial drugs.
Resistance analyses were done on 15 Eimeria acervulina strains and 5 E. brunetti strains. In all, 55% of these strains proved to have complex profiles of resistance to anticoccidial drugs as judged by resistance-index (RI) evaluation. Genomic fingerprints generated by random amplified DNA (RAPD) with 16 primers via the polymerase chain reaction (PCR) revealed a high degree of similarity (SI) between nonresistant strains (SI up to 95%). Polymorphisms including band shifts, differences in banding intensity, and missing bands led to significantly low SI values (57%, 69%, 82%) in drug-resistant Eimeria strains. After experimental induction of diclazuril resistance (1, 2, and 4 ppm) in a laboratory isolate VT-1 primer 5'-CCC TGA GAT GGG AAC CTC-3' amplified a polymorphic band of around 600 bp. Polymorphisms detected by RAPD-PCR will facilitate the selection of molecular markers and might lead to the design of diagnostic tests for drug-resistant genotypes.
Animal Health Department, BAYER AG Monheim, Leverkusen, Germany.
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G
Greif
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Stephan
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A
Haberkorn
D000818:Animals; D002645:Chickens; D003049:Coccidiostats / Q000494:pharmacology*; D016054:DNA, Protozoan / Q000032:analysis*; D004352:Drug Resistance, Microbial / Q000235:genetics; D004539:Eimeria / Q000187:drug effects / Q000235:genetics*; D009570:Nitriles / Q000494:pharmacology; D011110:Polymorphism, Genetic; D019105:Random Amplified Polymorphic DNA Technique; D014227:Triazines / Q000494:pharmacology
D003049:Coccidiostats; D016054:DNA, Protozoan; D009570:Nitriles; D014227:Triazines; C057884:diclazuril