title: Eimeria tenella: relative survival of drug-resistant and drug-sensitive populations in floor pen chickens.
abstract: The effect was studied of introducing about equal numbers of decoquinate-sensitive or decoquinate-resistant Eimeria tenella oocysts into a floor pen of susceptible unmedicated chickens. "Sentinel" birds introduced 2, 3, 4, 5, and 6 weeks later were used to recover populations of E. tenella oocysts. In drug sensitivity tests, populations of oocysts harvested at 4 weeks were partially resistant to decoquinate medication. Oocysts obtained after 5 and 6 weeks were highly sensitive to decoquinate medication. The results indicate that drug-sensitive E. tenella parasites are more likely to dominate in absence of medication.
mesh_terms: D000818:Animals; D002645:Chickens; D003048:Coccidiosis / Q000188:drug therapy / Q000662:veterinary; D003667:Decoquinate / Q000494:pharmacology / Q000627:therapeutic use*; D004351:Drug Resistance; D004539:Eimeria / Q000187:drug effects / Q000254:growth & development* / Q000302:isolation & purification; D005260:Female; D006912:Hydroxyquinolines / Q000627:therapeutic use*; D008297:Male; D011201:Poultry Diseases / Q000188:drug therapy
chemical_list: D006912:Hydroxyquinolines; D003667:Decoquinate