摘要
目的研究肺炎克雷伯菌对亚胺培南的耐药机制。方法采用浓度梯度法（Etest）测定细菌对各种抗菌药物最低抑菌浓度，聚合酶链反应（PCR）扩增β-内酰胺酶基因，并对扩增产物进行基因测序，用十二烷基硫酸钠一聚丙烯酰胺凝胶电泳（SDS—PAGE）进行外膜蛋白（OMP）分析。用抑制试验进行主动外排机制检测。结果4株菌株全部携带有SHV-12型和DHA-1型超广谱β-内酰胺酶（ESBLs）基因，3株携带CTX-M-14型ESBLs基因；4株菌外膜蛋白分析发现，肺炎克雷伯菌亚胺培南耐药株与敏感株相比，缺少分子量在32500-47500之间的一条带，从位置判断该条带可能为OMP36000或OMP37000的一种外膜蛋白；主动外排检测全部为阴性。结论同时产多种β-内酰胺酶合并外膜蛋白缺失可能是导致本组肺炎克雷伯菌对亚胺培南耐药的原因。
Objective To investigate the mechanism of Klebsiella pneumoniae resistant to imipenem. Methods The minimal inhibitive concentrations （MIC） of the antimicrobial agents was determined by Etest. The genes coded the β-lactamase were amplified by polymerase chain reaction （PCR）, and the sequences were analyzed. Outer membrane proteins （OMPs） were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）. Reserpine inhibition test was used to study the active efflux. Results All of the 4 strains of K. pneumonia produced SHV-12 and DHA-1 genotype. They also produced other β-lactamase （CTX- M-14 type, 3 isolates）. Compared to imipenem-sensitive isolates by SDS-PAGE, the imipenem-resistant isolates markedly lacked the protein band of about 36. 71ku which might be the outer membrane proteins of Omp 36,000 or Omp 37,000 according to the electrophoresis mobility. The active efflux test was negative. Conclusion Klebsiella pneumoniae produced more than one β-lactamase and the loss of outer membrane proteins may be accounted for the occurrence of imipenem resistance.
出处
《中国抗生素杂志》
CAS
CSCD
北大核心
2008年第11期668-670,共3页
Chinese Journal of Antibiotics
基金
广东省医学科研基金资助(A2005537)
