医院内鼠伤寒沙门菌病暴发流行菌株的研究

Study of Salmonella typhimurium Isolates from A Nosocomial Outbreak

苏州市儿童医院1989年发生一起鼠伤寒沙门菌病暴发流行。流行菌株为多重耐药菌,耐药种类达11～13种。质粒检测结果表明流行菌株均含四个质粒,最大质粒为122.6或103.3kb,其余三个为93.5、13.9和4.1kb。103.3kb质粒编码庆大霉素、卡那霉素和妥布霉素的耐药性。122.6kb质粒除编码上述三种药物的耐药性外,还编码对氯霉素、四环素及复方新诺明的耐药性。根据药敏试验、质粒检测和限制性内切酶分析,证实此次暴发流行是由两株不同的鼠伤寒沙门菌引起的。

An outbreak of disease caused by Salmonella typhimurium occurred in Suzhou Children's Hospital in 1989. All of isolates from patients were multiresistant to 11-13 antibiotics. The plas-mid profile showed that all of the epidemic strains possessed four plasmids. One was in size of approximately 122- 6 or 103. 3 kilobases. the others were 93. 5. 13. 9and 4. 1 kilobases. Plasmid curing revealed that 103-Skilobases plasmid was associated with resistance to gentamycin, kanamycin and tobramycin, and 122-Skilobases with that to gentamycin, kanamycin, to-bramycin chloramphenicol, tetracycline and sulfisoxazole-trimethoprim. According to antibiotic susceptibility and plasmid profile, epidemic strains were divided into two groups. Digestion of their plasmids with EcoRI and Hind Ⅲ further proved that each strain in the group originated from the same clone. All of the epidemic strains ware obviously different from two sporadic strains. These results together with clinical data indicated that this nosocomial outbreak was caused by different strains coming from two sources of infection.