Phenotypically Adapted Mycobacterium tuberculosis Populations from Sputum Are Tolerant to First-Line Drugs.
Phenotypically Adapted Mycobacterium tuberculosis Populations from Sputum Are Tolerant to First-Line Drugs.
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DOI：
10.1128/aac.01380-15
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发表时间：
2016-04
影响因子：
4.9
通讯作者：
Mukamolova GV
中科院分区：
文献类型：
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作者：
Turapov O;O'Connor BD;Sarybaeva AA;Williams C;Patel H;Kadyrov AS;Sarybaev AS;Woltmann G;Barer MR;Mukamolova GV
结核分枝杆菌痰中含有多种结核分枝杆菌，对体外分离有不同的要求。这些细胞包括在固体培养基上形成集落的细胞(可培养的结核分枝杆菌)，需要标准液体培养基才能生长的细胞(不可培养的结核分枝杆菌)，以及需要用培养上清(SN)补充液体培养基才能生长的细胞(依赖培养上清液的结核分枝杆菌)。在这里，我们描述了用于超低温保存和直接评估痰中结核分枝杆菌种群的抗菌素耐受性的方案。我们的结果表明，一线药物在7天内仅对所有三个群体产生温和的杀菌效果(减少1到2.5log10)，依赖SN的结核分枝杆菌对链霉素和异烟肼的耐受性高于可种植和不可种植的结核分枝杆菌菌株。可培养的结核分枝杆菌在体外传代后对杀菌药物的敏感性显著增加；因此，在人群组的痰样本中观察到的耐受性可能与分枝杆菌在咳痰前对宿主环境的适应有关。我们的发现支持使用一种简单的体外系统来测试对结核感染期间表型适应的分枝杆菌的药效。
Tuberculous sputum contains multiple Mycobacterium tuberculosis populations with different requirements for isolation in vitro. These include cells that form colonies on solid media (plateable M. tuberculosis), cells requiring standard liquid medium for growth (nonplateable M. tuberculosis), and cells requiring supplementation of liquid medium with culture supernatant (SN) for growth (SN-dependent M. tuberculosis). Here, we describe protocols for the cryopreservation and direct assessment of antimicrobial tolerance of these M. tuberculosis populations within sputum. Our results show that first-line drugs achieved only modest bactericidal effects on all three populations over 7 days (1 to 2.5 log10 reductions), and SN-dependent M. tuberculosis was more tolerant to streptomycin and isoniazid than the plateable and nonplateable M. tuberculosis strains. Susceptibility of plateable M. tuberculosis to bactericidal drugs was significantly increased after passage in vitro; thus, tolerance observed in the sputum samples from the population groups was likely associated with mycobacterial adaptation to the host environment at some time prior to expectoration. Our findings support the use of a simple ex vivo system for testing drug efficacies against mycobacteria that have phenotypically adapted during tuberculosis infection.