Detection of differentially culturable tubercle bacteria in sputum using mycobacterial culture filtrates.
Detection of differentially culturable tubercle bacteria in sputum using mycobacterial culture filtrates.
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DOI：
10.1038/s41598-021-86054-z
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发表时间：
2021-03-22
影响因子：
4.6
通讯作者：
Kana BD
中科院分区：
文献类型：
--
作者：
Gordhan BG;Peters JS;McIvor A;Machowski EE;Ealand C;Waja Z;Martinson N;Kana BD
快速检测结核病感染对遏制进一步传播至关重要。金标准仍然是分枝杆菌培养，但新出现的证据证实了临床标本中存在差异培养的结核菌（DCTB）。这些细菌在标准培养条件下不生长，需要来自结核分枝杆菌（Mtb）的纯培养物的培养滤液（CF）的存在才能出现。据推测，分子如复苏促进因子（Rpfs），脂肪酸和环腺苷酸（cAMP）存在于CF是负责的生长刺激活性。在此，我们测试了来自非致病性细菌耻垢分枝杆菌（Msm）的CF刺激DCTB生长的能力，因为这种生物体提供了更易处理的CF来源。我们还通过创建以各种组合表达Mtb rpf基因的Msm重组菌株来询问Mtb Rpfs在刺激DCTB中的作用。在治疗前，对来自具有药物敏感性TB的个体的痰测试源自该组菌株的CF。来自野生型Msm的CF不能以类似于Mtb CF制备物的方式检测DCTB，并且虽然与无CF对照相比，将RpfABMtb和RpfABCDEMtb添加到缺乏其天然rpf的Msm突变体中确实改善了DCTB的检测，但与空载体对照没有统计学差异。为了进一步研究Rpfs的作用，我们比较了有和没有Rpfs的来自Mtb的CF的生长刺激活性，发现这些是等效的。接下来，我们测试了化学上不同的脂肪酸和cAMP的生长刺激，虽然观察到了一些选择性刺激作用，但这并不显著高于培养基对照，并且与CF不可比较。总之，这些数据表明，Mtb CF观察到的生长刺激作用很可能是多种因素组合的结果。未来的工作旨在确定这些生长刺激分子的性质，可能有助于提高结核病的培养诊断。
Rapid detection of tuberculosis (TB) infection is paramount to curb further transmission. The gold standard for this remains mycobacterial culture, however emerging evidence confirms the presence of differentially culturable tubercle bacteria (DCTB) in clinical specimens. These bacteria do not grow under standard culture conditions and require the presence of culture filtrate (CF), from axenic cultures of Mycobacterium tuberculosis (Mtb), to emerge. It has been hypothesized that molecules such as resuscitation promoting factors (Rpfs), fatty acids and cyclic-AMP (cAMP) present in CF are responsible for the growth stimulatory activity. Herein, we tested the ability of CF from the non-pathogenic bacterium Mycobacterium smegmatis (Msm) to stimulate the growth of DCTB, as this organism provides a more tractable source of CF. We also interrogated the role of Mtb Rpfs in stimulation of DCTB by creating recombinant strains of Msm that express Mtb rpf genes in various combinations. CF derived from this panel of strains was tested on sputum from individuals with drug susceptible TB prior to treatment. CF from wild type Msm did not enable detection of DCTB in a manner akin to Mtb CF preparations and whilst the addition of RpfABMtb and RpfABCDEMtb to an Msm mutant devoid of its native rpfs did improve detection of DCTB compared to the no CF control, it was not statistically different to the empty vector control. To further investigate the role of Rpfs, we compared the growth stimulatory activity of CF from Mtb, with and without Rpfs and found these to be equivalent. Next, we tested chemically diverse fatty acids and cAMP for growth stimulation and whilst some selective stimulatory effect was observed, this was not significantly higher than the media control and not comparable to CF. Together, these data indicate that the growth stimulatory effect observed with Mtb CF is most likely the result of a combination of factors. Future work aimed at identifying the nature of these growth stimulatory molecules may facilitate improvement of culture-based diagnostics for TB.
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影响因子：
4.2
作者：
Machowski EE;Senzani S;Ealand C;Kana BD
通讯作者：
Kana BD
影响因子：
3.1
作者：
Downing, KJ;Mischenko, VV;Mizrahi, V
通讯作者：
Mizrahi, V
DOI：
10.1164/rccm.201604-0769oc
发表时间：
2016-12-15
影响因子：
24.7
作者：
Chengalroyen, Melissa D.;Beukes, Germar M.;Kana, Bavesh D.
通讯作者：
Kana, Bavesh D.
影响因子：
2.8
作者：
Shleeva, M;Mukamolova, GV;Kaprelyants, AS
通讯作者：
Kaprelyants, AS
影响因子：
3.7
作者：
Shleeva, Margarita;Goncharenko, Anna;Kaprelyants, Arseny
通讯作者：
Kaprelyants, Arseny