论文部分内容阅读
目的 分析志贺菌质粒谱、耐药性及流行菌株在遗传学上的同源关系。方法 用改良 Ｋａｄｏ Ｌｉｕ 法提取细菌质粒，琼脂糖凝胶电泳检测质粒，用平板稀释法测定药物最低抑菌浓度（ Ｍ Ｉ Ｃ） ，用试管内肉汤接合法和平板表面接合法进行接合转移试验。结果 １３０ 株志贺菌都含有５ 条小质粒带（ 除１ 条分子量稍大于６ ×１０６ 外，其余４ 条均小于６ ×１０６） ，１２８ 株含有１ 条分子量约为１２０ ×１０６ 的大质粒带，１８ 株有１ 或２ 条分子量介于３４ ～８０ ×１０６ 之间的质粒带；１５ 种抗生素的 Ｍ Ｉ Ｃ 测定结果显示，这些菌株对头孢三嗪、阿米卡星、头孢哌酮、头孢唑啉，庆大霉素敏感（ 敏感率为１００ ％ ～８８ ．６ ％ ， Ｍ Ｉ Ｃ９０为＜ ２ ～１０ μｇ／ｍｌ） ，对卡那霉素等其余１０ 种药物的敏感率很低或不敏感，不同质粒谱菌株对药物的敏感性几乎相同，对包括１８ 株含３４ ～８０ ×１０６ 质粒在内的２５ 株菌进行接合转移试验，未检出传递性耐药性质粒。结论 细菌的耐药性由非传递性的小质粒所携带，且大多流行菌株在遗传学上具有同源性相关。
Objective To analyze the plasmid spectrum, drug resistance of Shigella and the genetically homologous relationship among the strains. Methods Bacterial plasmids were extracted by modified Kado Liu method. Plasmid was detected by agarose gel electrophoresis. The minimum inhibitory concentration (M I C) of drug was determined by plate dilution method. test. Results All the 130 strains of Shigella contained five small plasmids (except one whose molecular weight was slightly larger than 6 × 106, the other four were less than 6 × 106), and 128 plants contained one large plasmid with a molecular weight of about 120 × 106 , 18 isolates with 1 or 2 plasmids with molecular weights between 34 and 80 × 106; M I C test results of 15 antibiotics showed that these strains were resistant to cefotaxime, amikacin, cefoperazone, The sensitivity of gentamicin to phenanthroline (sensitivity 100% ~ 88.6%, M I C90 <2 ~ 10 μg / ml) is very low or not sensitive to the remaining 10 drugs such as kanamycin Sensitive to different plasmid strains of the drug sensitivity is almost the same, including 18 strains containing 34 ~ 80 × 106 plasmids, including 25 strains of conjugation transfer test, no transmissible drug-resistant plasmid was detected. Conclusion The bacterial resistance is carried by small non-transmissible plasmids, and most of the strains are genetically related to their homology.