Studies of resistance to anticoccidials in Eimeria field isolates and pure Eimeria strains.
Ten Eimeria field isolates from North Germany were studied in battery tests for sensitivity to selected anticoccidials. A high percentage of the Eimeria field isolates (9 out of 10) showed resistance to anticoccidials, mostly multiple resistance. Partial or complete resistance to maduramicin was found in 7 field isolates, to monensin in 6, to salinomycin in 5, to nicarbazin in 8, to halofuginone in 7, to robenidine and toltrazuril in 1, and to diclazuril in 2 field isolates. Multiple resistance had developed in 7 of the 10 isolates. Cross-resistance between maduramicin, monensin, and salinomycin occurred in 5 Eimeria isolates. One isolate showed cross-resistance between diclazuril and toltrazuril. From the resistant isolates 15 pure E. acerculina and 5 pure E. brunetti strains were obtained by single oocyst infections. Seven of the E. acerculina and 4 of the E. brunetti strains showed resistance or partial resistance that was also present in the original isolate. Ten of 11 resistant strains were multiply resistant.
Stephen
B
B
Institute of Parasitology, School of Veterinary Medicine, Hannover, Germany.
Rommel
M
M
Daugschies
A
A
Haberkorn
A
A
D000818:Animals; D002645:Chickens; D003048:Coccidiosis / Q000469:parasitology / Q000662:veterinary*; D003049:Coccidiostats / Q000494:pharmacology*; D004351:Drug Resistance; D018432:Drug Resistance, Multiple; D004539:Eimeria / Q000187:drug effects* / Q000302:isolation & purification; D005858:Germany; D007783:Lactones / Q000494:pharmacology; D008297:Male; D008985:Monensin / Q000494:pharmacology; D009528:Nicarbazin / Q000494:pharmacology; D009570:Nitriles / Q000494:pharmacology; D010880:Piperidines; D011201:Poultry Diseases / Q000469:parasitology*; D011714:Pyrans / Q000494:pharmacology; D011799:Quinazolines / Q000494:pharmacology; D052999:Quinazolinones; D012370:Robenidine / Q000494:pharmacology; D014227:Triazines / Q000494:pharmacology; D000095662:Polyether Polyketides
D003049:Coccidiostats; D007783:Lactones; D008985:Monensin; D009528:Nicarbazin; D009570:Nitriles; D010880:Piperidines; D011714:Pyrans; D011799:Quinazolines; D052999:Quinazolinones; D012370:Robenidine; D014227:Triazines; C018091:maduramicin; C010327:salinomycin; D000095662:Polyether Polyketides; C057884:diclazuril; C010176:halofuginone; C036670:toltrazuril