Perlman D C, El Sadr W M, Heifets L B, Nelson E T, Matts J P, Chirgwin K, Salomon N, Telzak E E, Klein O, Kreiswirth B N, Musser J M, Hafner R
Beth Israel Medical Center, New York, NY 10003, USA.
AIDS. 1997 Oct;11(12):1473-8. doi: 10.1097/00002030-199712000-00011.
To characterize the susceptibility to levofloxacin of clinical isolates of Mycobacterium tuberculosis (MTB) obtained from patients with HIV-related tuberculosis and to characterize the molecular genetics of levofloxacin resistance.
Isolates from culture-positive patients in a United States multicenter trial of HIV-related TB were tested for susceptibility to levofloxacin by minimum inhibitory concentration (MIC) determinations in Bactec 7H12 broth. Automated sequencing of the resistance determining region of gyrA was performed.
Of the 135 baseline MTB isolates tested, 134 (99%; 95% exact binomial confidence interval, 95.9-99.9%) were susceptible to levofloxacin with an MIC < or = 1.0 microg/ml. We identified a previously unrecognized mis-sense mutation occurring at codon 88 of gyrA in a levofloxacin mono-resistant MTB isolate obtained from a patient with AIDS who had received ofloxacin for 8 months prior to the diagnosis of tuberculosis.
Clinical MTB isolates from HIV-infected patients were generally susceptible to levofloxacin. However, the identification of a clinical isolate with mono-resistance to levofloxacin highlights the need for circumspection in the use of fluoroquinolones in the setting of potential HIV-related tuberculosis and for monitoring of rates of resistance of MTB isolates to fluoroquinolones.
对从艾滋病相关结核病患者中分离出的结核分枝杆菌（MTB）临床菌株对左氧氟沙星的敏感性进行特征分析，并对左氧氟沙星耐药的分子遗传学特征进行分析。
在美国一项关于艾滋病相关结核病的多中心试验中，对培养阳性患者的菌株通过在Bactec 7H12肉汤中测定最低抑菌浓度（MIC）来检测其对左氧氟沙星的敏感性。对gyrA耐药决定区进行自动测序。
在检测的135株基线MTB菌株中，134株（99%；95%确切二项式置信区间，95.9 - 99.9%）对左氧氟沙星敏感，MIC≤1.0μg/ml。我们在一株对左氧氟沙星单耐药的MTB菌株中，于gyrA的88密码子处发现了一个先前未识别的错义突变，该菌株来自一名艾滋病患者，在结核病诊断前已接受氧氟沙星治疗8个月。
来自HIV感染患者的临床MTB菌株通常对左氧氟沙星敏感。然而，一株对左氧氟沙星单耐药的临床菌株的鉴定凸显了在潜在艾滋病相关结核病情况下使用氟喹诺酮类药物时需谨慎，以及监测MTB菌株对氟喹诺酮类药物耐药率的必要性。
