@article{TEXTUAL,
      recid = {10897},
      author = {Kang, Yu and Deng, Rui and Wang, Can and Deng, Tao and  Peng, Peichao and Cheng, Xiaoxing and Wang, Guoqing and  Qian, Minping and Gao, Huafang and Han, Bei and Chen,  Yusheng and Hu, Yinghui and Geng, Rong and Hu, Chengping  and Zhang, Wei and Yang, Jingping and Wan, Huanying and Yu,  Qin and Wei, Liping and Zhu, Xiangdong},
      title = {Etiologic diagnosis of lower respiratory tract bacterial  infections using Sputum samples and quantitative  loop-mediated isothermal amplification},
      journal = {PLOS ONE},
      address = {2012-06-14},
      number = {TEXTUAL},
      abstract = {Etiologic diagnoses of lower respiratory tract infections  (LRTI) have been relying primarily on bacterial cultures  that often fail to return useful results in time. Although  DNA-based assays are more sensitive than bacterial cultures  in detecting pathogens, the molecular results are often  inconsistent and challenged by doubts on false positives,  such as those due to system- and environment-derived  contaminations. Here we report a nationwide cohort study on  2986 suspected LRTI patients across P. R. China. We  compared the performance of a DNA-based assay qLAMP  (quantitative Loop-mediated isothermal AMPlification) with  that of standard bacterial cultures in detecting a panel of  eight common respiratory bacterial pathogens from sputum  samples. Our qLAMP assay detects the panel of pathogens in  1047(69.28%) patients from 1533 qualified patients at the  end. We found that the bacterial titer quantified based on  qLAMP is a predictor of probability that the bacterium in  the sample can be detected in culture assay. The  relatedness of the two assays fits a logistic regression  curve. We used a piecewise linear function to define  breakpoints where latent pathogen abruptly change its  competitive relationship with others in the panel. These  breakpoints, where pathogens start to propagate abnormally,  are used as cutoffs to eliminate the influence of  contaminations from normal flora. With help of the cutoffs  derived from statistical analysis, we are able to identify  causative pathogens in 750 (48.92%) patients from qualified  patients. In conclusion, qLAMP is a reliable method in  quantifying bacterial titer. Despite the fact that there  are always latent bacteria contaminated in sputum samples,  we can identify causative pathogens based on cutoffs  derived from statistical analysis of competitive  relationship. Trial Registration: ClinicalTrials.gov  NCT00567827.},
      url = {http://knowledge.uchicago.edu/record/10897},
}