连续消毒中大肠杆菌O157:H7对消毒剂抗力的变化及其与质粒关系的研究

STUDY ON CHANGES IN RESISTANCE OF Escherichia coli O157∶H7 TO DISINFECTANTS DURING CONTINUOUS DISINFECTION AND THEIR RELATION TO PLASMID

为了研究 5 0代连续消毒中大肠杆菌O15 7:H7对两种消毒剂抵抗力的变化及其与质粒的关系 ,用二氯异氰尿酸钠、碘伏连续消毒 6株大肠杆菌O15 7:H75 0代 ,对比消毒前后试验菌对两种消毒剂的抵抗力 ,观察消除试验菌质粒后抗力的变化。结果 ,连续消毒 5 0代后 ,试验菌对二氯异氰尿酸钠、碘伏的抵抗力增加。消除原始菌的小质粒后 ,细菌对消毒剂的抵抗力不变 ;消除原始菌的所有质粒后 ,试验菌对二氯异氰尿酸钠的抵抗力不变 ,对碘伏的抵抗力增加 ;消除连续消毒后试验菌的质粒后 ,其对二氯异氰尿酸钠的抵抗力降低到原始菌的水平 ,对碘伏的抵抗力增加。试验结果提示 ,连续消毒会使试验菌对二氯异氰尿酸钠、碘伏的抵抗力增加 ;试验菌对二氯异氰尿酸钠抵抗力增加的原因可能与质粒pO15 7相关 ,对碘伏抵抗力增加与质粒pO15 7无直接关系。

In order to study the changes of resistance of Escherichia coli O157:H7 to two disinfectants during continuous disinfection of 50 generations and their relation to plasmid, continuous disinfection of 50 generations of 6 strains of E. coliO157:H7 with sodium dichloroisocyanurate and iodophor was used to compare the resistance of the test bacteria to the two disinfectants before and after disinfection and to observe the changes in resistance after removing the plasmid of the test bacteria. The results showed that after continuous disinfection of 50 generations, the resistance of the test bacteria to sodium dichloroisocyanurate and iodophor increased. After removing the small plasmid of the original bacteria, the resistance of the bacteria to the disinfectants did not change; after removing all plasmids of the original bacteria, the resistance of the test bacteria to sodium dichloroisocyanurate did not change, while the resistance to iodophor increased; after removing the plasmid of the test bacteria after continuous disinfection, their resistance to sodium dichloroisocyanurate decreased to the level of the original bacteria, while the resistance to iodophor increased. The results of the tests indicated that continuous disinfection would increase the resistance of the test bacteria to sodium dichloroisocyanurate and iodophor. The cause of increase in resistance of the test bacteria to sodium dichloroisocyanurate may be related to plasmid pO157, while the increase in resistance to iodophor is not related directly to plasmid pO157.