Abate G, Miörner H
Department of Mycobacteriology, Statens Serum Institut, Copenhagen, Denmark.
J Antimicrob Chemother. 1998 Dec;42(6):735-40. doi: 10.1093/jac/42.6.735.
Thirty clinical isolates of Mycobacterium tuberculosis, 20 of which were multidrug-resistant (MDR), were tested for susceptibility to different combinations of amoxycillin, clavulanic acid and subinhibitory concentrations of ethambutol. beta-Lactamase production was assessed semiquantitatively with the nitrocefin method and susceptibility testing was performed with the BACTEC method. All isolates were beta-lactamase positive and were resistant to 16 mg/L amoxycillin. The MIC of amoxycillin in combination with clavulanic acid was > or =2 mg/L for 27/30 (90%) isolates. Addition of subinhibitory concentrations of ethambutol significantly reduced the MIC of amoxycillin for all tested isolates. Twenty-nine (97%) isolates had an MIC of amoxycillin of < or =0.5 mg/L when subinhibitory concentrations of ethambutol were added; this is well below the concentrations achievable in serum and tissue.
对30株结核分枝杆菌临床分离株进行了测试，其中20株为多重耐药（MDR），检测它们对阿莫西林、克拉维酸和亚抑菌浓度乙胺丁醇不同组合的敏感性。采用硝基头孢菌素法半定量评估β-内酰胺酶的产生情况，并使用BACTEC法进行药敏试验。所有分离株均为β-内酰胺酶阳性，且对16mg/L阿莫西林耐药。对于27/30（90%）的分离株，阿莫西林与克拉维酸联合使用时的最低抑菌浓度（MIC）≥2mg/L。添加亚抑菌浓度的乙胺丁醇可显著降低所有受试分离株的阿莫西林MIC。当添加亚抑菌浓度的乙胺丁醇时，29株（97%）分离株的阿莫西林MIC≤0.5mg/L；这远低于血清和组织中可达到的浓度。
