Abstract: 56 strains of swine pathogenic E.coli were isolated from 23 small and medium-scale pig farms in Guangxi, and its serotype identification and detection of drug resistance showed that the 56 strains belonged to 16 serotypes, out of which O serotype viz, O₁₃₈,O₁₈,O₈₅,O₉,O₂₁ were predominant, occupying 69.76%. The detection of drug resistance of 20 frequently used antibiotics indicated that most E.coli trains were highly sensitive to Cephradine, Cefazolin, Ceftriaxone, Cefoxitin, Polymyxin B, Neomycin, Spectinomycin, and Amikacin, but insensitive to Penicillin, Amoxicillin, Doxycycline, Kanamycin, Vancomycin, Lincomycin, which points to the fact that drug resistance of E.coli in these pig farms has been very grave, and that measures such as biotic safety should be strengthened to undertake comprehensive prevention.

Key words: Escherichia coli; serotype; sensitivity test; small and medium-scale farm in Guangxi