Song Jianxin, Ruan Qiurong, Qi Junying, Gao Meiying, Wang Yiguang
Department of Infectious Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030.
J Huazhong Univ Sci Technolog Med Sci. 2002;22(4):339-42. doi: 10.1007/BF02896781.
To study the resistant mechanism and clinical significance of pseudomonas aeruginosa to beta-lactam antibiotics, the outer membrane permeability rate of 30 P. aeruginosa strains to 5 beta-lactam antibiotics was measured and their production of beta-lactamase and the beta-lactamase genes they carried detected. Furthermore, the relationship between the permeability, beta-lactamase and the clinical effects of beta-lactam antibiotics was observed. By using 14C-penicillin and liquid-scintillant isotope assay, the affinity of penicillin binding proteins (PBPS) was measured and their roles in the resistant mechanism studied. It was revealed that the permeability rate was higher in sensitive strains than in resistant ones (P < 0.05). All strains harbored 1-4 beta-lactamase genes and produced beta-lactamase. Higher permeability rate and higher degree of stability to beta-lactamase indicated better clinical therapeutic effects. The affinity of PBPs changed little without regard to the permeability and beta-lactamase. These results suggested that the permeability of outer membrane and beta-lactamase, but not PBPs, played important roles in the resistant mechanism of P. aeruginosa to beta-lactam antibiotics and affected the clinical therapeutic effectiveness of some patients.
为研究铜绿假单胞菌对β-内酰胺类抗生素的耐药机制及临床意义，测定了30株铜绿假单胞菌对5种β-内酰胺类抗生素的外膜通透率，检测了其β-内酰胺酶的产生及携带的β-内酰胺酶基因。此外，观察了通透性、β-内酰胺酶与β-内酰胺类抗生素临床疗效之间的关系。采用14C-青霉素和液体闪烁同位素分析法测定青霉素结合蛋白（PBPs）的亲和力，并研究其在耐药机制中的作用。结果显示，敏感菌株的通透率高于耐药菌株（P<0.05）。所有菌株均携带1 - 4个β-内酰胺酶基因并产生β-内酰胺酶。较高的通透率和对β-内酰胺酶较高的稳定性表明临床治疗效果较好。PBPs的亲和力变化不大，与通透性和β-内酰胺酶无关。这些结果表明，外膜通透性和β-内酰胺酶而非PBPs在铜绿假单胞菌对β-内酰胺类抗生素的耐药机制中起重要作用，并影响部分患者的临床治疗效果。
