鼠伤寒沙门氏菌耐药质粒的研究

摘要

1982年10～11月在上海暴发流行期收集的45株鼠伤寒沙门氏菌流行株中,对氨苄青霉素、氯霉素、四环素、庆大霉素、卡那霉素、链霉素、氧哌嗪青霉素和复方SMz-TMP的耐药者占73.3%,对5种或5种以上抗菌药物耐物药者占93.7%;而同期从带菌者中分离的9株鼠伤寒沙门氏菌非流行株中仅工株为多重耐药株.接合转移和转化试验证明,细菌的多重耐药性乃耐药(R)质粒(抗性或耐药质粒)所介导,25%在五质粒可将其耐药性转移给大肠杆菌KRif/12,转移频率为10-4～10-6.琼脂糖凝胶电泳显示:流行株的质粒谱相似+均有5～6个质粒带,其中大质粒与多重耐药性有关;而非流行株仅有一个质粒带.%From Ooc 10 Nov 1982,45 epidemie strains of S.typhimurium were collected from several outbreaks in Shanghai. 73.8% of them were resistant to ampieillin, chlormaphenicol,tetracycline,gentamiein,kanamycin,streptomyein,piperacillin,and SMZ Co,and 93.2% were resistant to 5 anttmicrobial agents at least.However,only one out of 9 strains,isolated from S,typhimurium carriers,was multiresisfant.By conjugation and transformation,the multiresistance was shown to be plasmid-mediated.25% of R plasmids were transferable to E.coli K12Rlf with a frequency of-4 to 10-6.Electrophoresis in agaross gel of plasmid preparationg showed that the plastaid pattern of epidemic strains were similar,each of them had 5～6 plasmid bands,the larger plasmids were the genes responsible for multiresistance.In contrast,there was only one plasmid band in the non-epidemic strain.