头孢他啶（GR 20263）及其他β-内酰胺酶稳定型头孢菌素对铜绿假单胞菌的体外比较活性。接种量及二价阳离子补充的影响。

Comparative in-vitro activity of ceftazidime (GR 20263) and other beta-lactamase stable cephalosporins against pseudomonas. Effect of inoculum size and divalent cation supplementation.

作者信息

Chow A W, Bartlett K H

机构信息

Division of Infectious Disease, Department of Medicine, University of British Columbia and Vancouver General Hospital, Vancouver, B.C., Canada.

出版信息

J Antimicrob Chemother. 1981 Sep;8 Suppl B:345-8. doi: 10.1093/jac/8.suppl_b.345.

DOI:10.1093/jac/8.suppl_b.345

PMID:19803012

Abstract

The anti-pseudomonal activity of ceftazidime was determined by an agar-dilution technique against 92 strains of Pseudomonas aeruginosa and 22 non-aeruginosa isolates and compared with that of cefoperazone, moxalactam and ceftizoxime. Against Ps. aeruginosa, ceftazidime and cefoperazone were comparable in activity and both were significantly more active than moxalactam and ceftizoxime (P < 0001). At 16 mg/l, 95% of strains were inhibited by ceftazidime, compared to 94% by cefoperazone, 80% by moxalactam and 25% by ceftizoxime. A three- to four-fold increase in geometric mean MIC for ceftazidime, moxalactam and ceftizoxime, and a 23-fold increase for cefoperazone was observed with a larger inoculum of 10(6) cfu, demonstrating a marked inoculum effect. Additionally, divalent cation (calcium and magnesium) concentrations of the test medium also influenced the in-vitro results for ceftazidime and cefoperazone, but not for moxalactam or ceftizoxime. Against non-aeruginosa strains, cefoperazone was most active while ceftizoxime was less effective.

摘要

采用琼脂稀释法测定了头孢他啶对92株铜绿假单胞菌和22株非铜绿假单胞菌分离株的抗假单胞菌活性，并与头孢哌酮、拉氧头孢和头孢唑肟进行了比较。对于铜绿假单胞菌，头孢他啶和头孢哌酮的活性相当，且两者均显著高于拉氧头孢和头孢唑肟（P<0.001）。在16mg/L时，95%的菌株被头孢他啶抑制，相比之下，头孢哌酮为94%，拉氧头孢为80%，头孢唑肟为25%。接种量为10(6)cfu时，头孢他啶、拉氧头孢和头孢唑肟的几何平均最低抑菌浓度（MIC）增加了三到四倍，头孢哌酮增加了23倍，显示出明显的接种量效应。此外，测试培养基中二价阳离子（钙和镁）的浓度也影响头孢他啶和头孢哌酮的体外结果，但不影响拉氧头孢或头孢唑肟。对于非铜绿假单胞菌菌株，头孢哌酮活性最强，而头孢唑肟效果较差。