In pathogen diagnostics, conventional culture-based assays remain the gold-standard; however, they are time-consuming, and shows the low positivity rate. Prior treatment with antibiotics is one of the major factors lowering the culture positivity rate. It is therefore important to evaluate the effects of prior antibiotic treatment on established detection methods and to develop sensitive and specific methods for detecting pathogens. Here, we report the detection of bacteria in samples containing antibiotics. Escherichia coli and Klebsiella pneumoniae were chosen as model and they were independently inoculated into culture flasks along with ceftriaxone (0.5× MIC, 1× MIC, 2× MIC). After 0, 2, 4, 6, 12, and 24 h, samples were collected from each flask and divided into two for evaluation using microarray or BacT/Alert culture-based systems. The newly designed probes showed a detection limit of 10¹ CFU for E. coli and 10² CFU for K. pneumoniae with high specificities. DNA microarray obtained true positive results at approximately 4 to 24 h after antimicrobial treatment, in which the culture-based method failed to detect the pathogenic bacteria. The DNA microarray-based assay could be useful for efficient detection of pathogenic bacteria in a clinical setting, allowing for appropriate administration of antibiotics in infected patients.

在病原体诊断中，传统的基于培养的检测方法仍然是金标准；然而，它们很耗时，并且显示出低阳性率。预先用抗生素治疗是降低培养阳性率的主要因素之一。因此，重要的是评估先前抗生素治疗对已建立的检测方法的影响，并开发用于检测病原体的灵敏和特异的方法。在这里，我们报告了在含有抗生素的样品中检测细菌的情况。大肠杆菌和肺炎克雷伯菌被选为模型，它们与头孢曲松（0.5×MIC、1×MIC、2×MIC）一起独立接种到培养瓶中。在 0、2、4、6、12 和 24 小时后，从每个烧瓶中收集样品并分成两份，使用微阵列或 BacT/Alert 培养系统进行评估。新设计的探针对大肠杆菌的检测限为 10 ¹ CFU，对肺炎克雷伯菌的检测限为10 ² CFU具有高特异性。DNA微阵列在抗菌治疗后约4至24小时获得真阳性结果，其中基于培养的方法未能检测到病原菌。基于 DNA 微阵列的检测可用于有效检测临床环境中的病原菌，从而允许在受感染的患者中适当施用抗生素。