| Summary: | 碩士 === 國立屏東科技大學 === 獸醫學系 === 94 === 177 Escherichia coli ( E. coli ) -suspected samples from 360 pigs that died from the E. coli suspected infections were cultured to isolate and detect this pathogens. Thirty five samples of 177 E. coli-suspected samples were identified to be hemolytic E. coli ( HEC ) infections. The positive rate was 19.7 ％ ( 35/177 ). HEC nucleic acid was extracted from pure culture colony and amplified by polymerase chain reaction ( PCR ) using the two specific primers that design for amplification of the heat-labile enterotoxin ( LT ) gene 360 bp or heat-stable enterotoxin ( ST ) gene ( ST1 160 bp, ST2 423 bp ), eaeA 241 bp, respectively. Results of the multiplex PCR analysis for detect the LT1, ST1 and ST2 toxic genes of HEC, the only had LT1 gene were 11.43 ％ ( 4／35 ), both had LT1 and ST2 genes were 5.71 ％ ( 2／35 ), and both had the LT1, ST1 and ST2 genes were 82.86 ％ ( 29／35 )。A drug sensitivity test was performed to determine the sensitivity of isolated HEC strains to 28 drugs. HEC had resistant to most commercial drugs ( Amoxicillin, Ampicillin, Chloramphenicol, Gentamycin, Erythromycin, Ceftiofur, Baytril, Furazolidone, Kanamycin, Cephalothin, Methicillin, Lincomycin, Neomycin, Nalidixic acid, Oxolinic acid, Penicillin G, Streptomycin, Flumequine, Vancomycin, Linco-spectin, Tiamulin + Tetra, Ciprofloxacin, Sarafloxacin HCI ), except for Ceftiofur, Nitrofurauntoin, Florfenicol, Tetracycline, Sulfamethoxazole ＋ Trimethoprim, Trimethoprim. The findings of drugs resistance were indicated that neonatal and weaned pigs with colibacillosis caused by HEC was usually difficult to be treated due to drug resistance. The results of the study may provide the information for clinical prevention and treatment of colibacillosis in piglets.
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