Laser optical sensor, a label-free on-plate Salmonella enterica colony detection tool.
Laser optical sensor, a label-free on-plate Salmonella enterica colony detection tool.
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DOI：
10.1128/mbio.01019-13
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发表时间：
2014-02-04
期刊：
影响因子：
6.4
通讯作者：
Bhunia AK
中科院分区：
文献类型：
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作者：
Singh AK;Bettasso AM;Bae E;Rajwa B;Dundar MM;Forster MD;Liu L;Barrett B;Lovchik J;Robinson JP;Hirleman ED;Bhunia AK
我们研究了激光光学传感器的应用能力，BARDOT（使用光学散射技术的细菌快速检测），以产生不同的散射模式的20个最常见的肠道沙门氏菌血清型。最初，该研究通过使用在脑心浸液、亮绿色、木糖赖氨酸脱氧胆酸盐和木糖赖氨酸tergitol 4（XLT 4）琼脂平板上生长的6种沙门氏菌血清型来测试BARDOT的分类能力。通过使用从在XLT 4上生长的菌落收集的散射特征，获得了高度准确的区分（95.9%）。进一步验证使用了总共36个血清型（前20个加16个），包括123个菌株，分类精度水平为88 - 100%。通过BARDOT分析的菌株的光学表型之间的相似性与通过脉冲场凝胶电泳（PFGE）分析的基因型基本一致。对BARDOT进行了评价，以实时检测和鉴定从接种的（1.2 × 102 CFU/30 g）花生酱、鸡胸肉和菠菜或自然污染的肉类中生长的沙门氏菌菌落。在缓冲蛋白胨水和改良Rappaport Vassiliadis肉汤中连续富集4 h后，随后在XLT 4上生长（约16 h），BARDOT在24 h内检测到鼠伤寒沙门氏菌，准确度为84%，返回的结果与USDA食品安全和检验服务方法相当，该方法需要约72 h。BARDOT还检测沙门氏菌（90%至100%的准确性）的存在下，从自然污染的肉类背景微生物群，通过16 S rRNA测序和PFGE验证。沙门氏菌在花生酱中长时间停留（28天）并不影响细菌形成具有一致光学表型的菌落的能力。这项研究表明，BARDOT的潜在的非破坏性和高通量检测食品样品中的沙门氏菌。高通量食品病原体筛查将对减少食源性危害产生重大影响。开发了一种激光光学传感器，用于在不损坏菌落的情况下立即在琼脂平板上筛选病原体菌落;该方法有助于通过经典的基于微生物培养的方法进行早期病原体检测。在这里，我们证明了这种传感器能够检测36个沙门氏菌血清型测试，包括前20个血清型，并确定前8个沙门氏菌血清型的分离株。此外，它可以在24小时内检测出存在背景微生物群的食品样品中的沙门氏菌，而美国农业部食品安全和检验局的标准方法需要约72小时。
We investigated the application capabilities of a laser optical sensor, BARDOT (bacterial rapid detection using optical scatter technology) to generate differentiating scatter patterns for the 20 most frequently reported serovars of Salmonella enterica. Initially, the study tested the classification ability of BARDOT by using six Salmonella serovars grown on brain heart infusion, brilliant green, xylose lysine deoxycholate, and xylose lysine tergitol 4 (XLT4) agar plates. Highly accurate discrimination (95.9%) was obtained by using scatter signatures collected from colonies grown on XLT4. Further verification used a total of 36 serovars (the top 20 plus 16) comprising 123 strains with classification precision levels of 88 to 100%. The similarities between the optical phenotypes of strains analyzed by BARDOT were in general agreement with the genotypes analyzed by pulsed-field gel electrophoresis (PFGE). BARDOT was evaluated for the real-time detection and identification of Salmonella colonies grown from inoculated (1.2 × 102 CFU/30 g) peanut butter, chicken breast, and spinach or from naturally contaminated meat. After a sequential enrichment in buffered peptone water and modified Rappaport Vassiliadis broth for 4 h each, followed by growth on XLT4 (~16 h), BARDOT detected S. Typhimurium with 84% accuracy in 24 h, returning results comparable to those of the USDA Food Safety and Inspection Service method, which requires ~72 h. BARDOT also detected Salmonella (90 to 100% accuracy) in the presence of background microbiota from naturally contaminated meat, verified by 16S rRNA sequencing and PFGE. Prolonged residence (28 days) of Salmonella in peanut butter did not affect the bacterial ability to form colonies with consistent optical phenotypes. This study shows BARDOT’s potential for nondestructive and high-throughput detection of Salmonella in food samples. High-throughput screening of food products for pathogens would have a significant impact on the reduction of food-borne hazards. A laser optical sensor was developed to screen pathogen colonies on an agar plate instantly without damaging the colonies; this method aids in early pathogen detection by the classical microbiological culture-based method. Here we demonstrate that this sensor was able to detect the 36 Salmonella serovars tested, including the top 20 serovars, and to identify isolates of the top 8 Salmonella serovars. Furthermore, it can detect Salmonella in food samples in the presence of background microbiota in 24 h, whereas the standard USDA Food Safety and Inspection Service method requires about 72 h.