| Study on the Biological Characheristics of Field Strains of E.tenella in Hebei Province Using single-oocyst separation technology, three Eimeria tenella (E.tenella) field strains in Hebei province were isolated and identified as E.tenella Qinhuangdao strain, Tangshan strain, and Shijiazhuang strain, then their biological characheristics were detected and compared with E.tenella sensitive strain and resistat salinomycin strain. The results showed that (1) Oocysts of all strains parasitized in mecums,and were broadly ovoid with a smoth wall.(2)The prepatent period of Tangshan strain was the longest, being 142h, but the prepatent periods of Qinhuangdao strain and Shijiazhuang strain were similar to those of sensitive strain and resistant salinomycin strain,being 137h,133h,132h and 135h respectively.(3)The minimum sporulation time of Qinhuangdao strain,Tangshan strain,Shijiazhuang strain,sensitive strain and resistant salinomycin strain was 19h,17h,20h,20h and 18h, respectively.(4)The oocysts sizes of Tangshan strain,Shijiazhuang strain, Qinhuangdao strain and resistant salinomycin strain were 24.11μm×19.07μm,23.41μm×19.34μm, 24.89μm×20.14μm and 24.06μm×19.50μm respectively, their shape indexes were 1.26,1.21,1.24 and 1.23, but the oocyst size of sensitive strain was 24.13μm×20.37μm, its shape index was the smallest,being 1.18. (5) The perk production of oocysts of different strains was 7 to 8 days after infection, and its ration of yield of oocysts to total yield from 7 to 9 day after infection was 75.62% to 86.06%.The results provided a basis for drug control and study on drug-resistant mechanism.Detection of Drug Resistance to the Field Strains of E.tenella and Analysis on Change of Drug-Resistant Spectrum in Hebei Province Based on the criteria of the percent of optimum anticoccidial activity (POAA), reduction of lesion scores (RLS),relative oocyst production (ROP) and anticoccidial index (ACI), the drug resistances of E.tenella Qinhuangdao strain, Tanshan strain and Shijiazhuang strain in Hebei provoince to common used anticoccidial drugs such as keqiufen, amprolium, maduramicin, ruiguanqiu, nicarbazin, jinsante and qiudi were detected by drug sensitive test. The results revealed that Qinhuangdao strain was complete resistant to qiudi, middle resistant to keqiufen, ruiguanqiu and jinsante, but light resistant to maduramicin, nicarbazin and amprolium. Tanshan strain was no resistant to nicarbazin and amprolium, middle resistant to keqiufen and ruiguanqiu, but complete resistant to maduramicin, jinsante and qiudi. Shijiazhuang strain was no resistant to jinsante and amprolium, light resistant to ruiguanqiu, but complete resistant to maduramicin, keqiufen and qiudi. At the same time the change on the drug-resistant spectrums of E. tenella Qinhuangdao strain isolated from 2004 to 2008 year was analysed by the method of review investigation. The results revealed that resistant spectrum of E. tenella to common anticoccidial drugs was broad, resistant rate was increasing in recent years, and the sensitive was recoved in certain degree after anticoccidial drugs were stoped using for some times. The results provided a reliable basis on effectivelly controlling chicken coccidosis.Isolation on the Related Genes of Drug Resistance of Field Strains of E.tenella in Hebei Province The total RNA of E.tenella sensitive strain and drug-resistant strains from Qinhuangdao,Tangshan and Shijiazhuang were extracted with Trizol. DDRT-PCR of three strains was established by using 3 anchored primers and 20 arbitrary primers. Their products of PCR were analysed on the denaturing polyacrylamide gels by silver-staining.Twenty-six differential fragments were excised from the gels and reamplified with the same sets of primers. Then the PCR products were purified and extracted 12 differential expression fragments with about 20 to 50ng in concentration. Twelve differential expression fragments were cloned with PMD-18T vector and identifed by reverse Northen dot hybridization, so three positive gene fragments related to drug resistance of E.tenella field resistant strains were isolated. After sequence analysis with sequence in Genebank and Sanger, the sequence S116 from mRNA of Shijiazhuang drug-resistant strain was similar to the sequence of first chromosome with 882bp in length.The similarity was 99% and it was an unknown protein,but the sequences T311 and Q19 from mRNA of Tangshan and Qinhuang drug-resistant strains were respectively unknown. These drug-resistant relative genes maybe be involved in the development of drug resistance. |
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