Eimeria Tenella: Experimental Studies On The Development Of Resistance To Maduramycin

The development of resistance by the Houghton strain of Eimeria tenella to madurarnycin was studied by serially passaging the strain in chickens medicated with progressively greater concentrations of drug and the SDS-PAGE technique was practiced to test the hypothesis that protein variations were associated with maduramycin resistance. The methodology used by Weppelman et al(1977) was also applied to test Weppelman et al hypothesis that resistance result from selection rather than adaptation. After 33 passages with 2 mg/kg maduramycin as the primary concentration, a line of the strain which became resistant to 3 mg/kg maduramycin was developed. SDS-PAGE revealed that: one peptide with molecular weight of approximately 228.5 kDa was present in the sporulated oocysts of the resistance line but undetectable in its Houghton-parent sporulated oocysts and a peptide with molecular weight of approximately 18.66 kDa was highly expressed in the resistance line, while another peplidc with molecular weight of approximately 9.3 kDa was present in the sporulated oocysts of the parent oocysts but undetectable in its resistance line. The failure to select a mutated line against maduramycin suggest that multple mulation sites might exist in the strain.