大肠杆菌O157:H7对消毒剂抗力与质粒pO157关系的研究

STUDY ON RELATIONSHIP BETWEEN RESISTANCE OF Escherichia coli O157 : H7 TO DISINFECTANTS AND PLASMID pO157

用高温-SDS法消除大肠杆菌O157:H7的质粒pO157,并将质粒pO157转化到大肠杆菌JM109,对比质粒pO157消除和转化前后试验菌对4种消毒剂的抵抗力。结果,质粒pO157消除后,试验菌对季铵盐的抵抗力有明显降低,对碘伏的抵抗力有明显的增强,对二氯异氰尿酸钠、醋酸氯己定的抵抗力无变化;将pO157转化到大肠杆菌JM109后,阳性转化菌对4种消毒剂的抵抗力均有不同程度增强,其中对季铵盐的抵抗力增加近60倍。结果提示,质粒pO157上可能带有抵抗季铵盐的基因而未携带抗碘伏的基因;消除质粒pO157后的试验菌对碘伏的抗性增加却说明pO157与试验菌对碘伏的抵抗力有间接关系。

Plasmid pO157 of Escherichia coli O157 : H7 was eliminated with high temperature-SDS method and transformed to E. coli JM109. The resistance of E. coli O157 : H7 to 4 disinfectants before and after elimination and transformation of plasmid pO157 was compared. The results showed that after eliminating plasmid pO157, the resistance of test bacteria to quaternary ammonium salts decreased obviously, resistance to iodophor increased obviously and resistance to sodium dichloroisocyanurate and chlorhexidine acetate did not change. After transforming pO157 to E. coli JM109, the resistance of positive transformed bacteria to 4 disinfectants increased to various degrees and the resistance to quaternary ammonium salts increased by near 60-folds. The results suggest that plasmid pO157 may carry the gene resistant to quaternary ammonium salts and no gene resistant to iodophor. Increase in resistance of the test bacteria to iodophor af-ter eliminating plasmid pO157 indicates that pO157 has indirect relation to the resistance of test bacteria to iodophor.