The relationship between Mycobacterium tuberculosis MGIT time to positivity and cfu in sputum samples demonstrates changing bacterial phenotypes potentially reflecting the impact of chemotherapy on critical sub-populations
The relationship between Mycobacterium tuberculosis MGIT time to positivity and cfu in sputum samples demonstrates changing bacterial phenotypes potentially reflecting the impact of chemotherapy on critical sub-populations
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DOI：
10.1093/jac/dku415
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发表时间：
2015-02-01
影响因子：
5.2
通讯作者：
Gillespie, Stephen H.
中科院分区：
文献类型：
--
作者：
Bowness, Ruth;Boeree, Martin J.;Gillespie, Stephen H.
目的：cfu 和分枝杆菌生长指示管 (MGIT) 呈阳性时间 (TTP) 之间的关系尚不确定。我们试图理解这种关系并创建一个数学模型来关联这两种确定分枝杆菌负荷的方法。方法：收集由 MGIT 和 cfu 确定的临床试验的连续细菌学负荷数据并导出数学模型。所有模型拟合均在 R 统计软件环境（版本 3.0.2）中使用 lm 和 nls 函数进行。结果：在研究的所有 14 天中，TTP 均与 log(10) cfu 呈负相关。随着治疗的进展，回归线和 y 截距的梯度逐渐增加。随着利福平剂量的增加，梯度也呈增加趋势。结论：这些数据表明，在液体培养基中检测到的分枝杆菌细胞群数量比在固体培养基中检测到的数量更多。增加利福平剂量会不同程度地杀死这组生物。这些发现支持增加利福平剂量更有效的观点。
Objectives: The relationship between cfu and Mycobacterial Growth Indicator Tube (MGIT) time to positivity (TTP) is uncertain. We attempted to understand this relationship and create a mathematical model to relate these two methods of determining mycobacterial load.Methods: Sequential bacteriological load data from clinical trials determined by MGIT and cfu were collected and mathematical models derived. All model fittings were conducted in the R statistical software environment (version 3.0.2), using the lm and nls functions.Results: TTP showed a negative correlation with log(10) cfu on all 14 days of the study. There was an increasing gradient of the regression line and y-intercept as treatment progressed. There was also a trend towards an increasing gradient with higher doses of rifampicin.Conclusions: These data suggest that there is a population of mycobacterial cells that are more numerous when detected in liquid than on solid medium. Increasing doses of rifampicin differentially kill this group of organisms. These findings support the idea that increased doses of rifampicin are more effective.