Optical forward-scattering for identification of bacteria within microcolonies
Optical forward-scattering for identification of bacteria within microcolonies
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DOI：
10.1007/s00253-013-5495-4
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发表时间：
2014-03-01
影响因子：
5
通讯作者：
Mallard, Frederic
中科院分区：
文献类型：
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作者：
Marcoux, Pierre R.;Dupoy, Mathieu;Mallard, Frederic
开发快速鉴定病原菌的方法是加快传染病临床诊断和有效控制食品和水安全的重要一步。用于鉴定凝胶化营养肉汤上的细菌菌落的方法具有带来有吸引力的解决方案的潜力，其在非破坏性过程中结合简单的光学仪器，不需要样品制备或标记。在这里，我们研究了在非常早期的生长阶段（在37摄氏度下孵育6小时），在薄层琼脂培养基（1毫米的胰蛋白酶大豆琼脂）上，使用光前向散射和学习算法（贝叶斯网络，连续朴素贝叶斯，顺序最小优化）区分不同细菌种类的可能性。在7个革兰氏阴性菌株上获得的超过1，000个散点图的第一个数据库在仅孵育6小时后产生了近80%的识别率。我们还研究了通过前向散射识别同一物种的不同菌株的前景。我们区分，因此，四株大肠杆菌的识别率达到82%。最后，我们展示了两种凝固酶阴性葡萄球菌（S。haemolyticus和S. cohnii），在临床诊断中使用的商业选择性预倾倒培养基（ChromID MRSA，bioMerieux）上，在散点图采集期间不打开盖子。这显示了这种方法的潜力-非侵入性，防止交叉污染，需要最少的培养皿处理-在全自动微生物实验室的背景下提供早期临床相关信息。
The development of methods for the rapid identification of pathogenic bacteria is a major step towards accelerated clinical diagnosis of infectious diseases and efficient food and water safety control. Methods for identification of bacterial colonies on gelified nutrient broth have the potential to bring an attractive solution, combining simple optical instrumentation, no need for sample preparation or labelling, in a non-destructive process. Here, we studied the possibility of discriminating different bacterial species at a very early stage of growth (6 h of incubation at 37 degrees C), on thin layers of agar media (1 mm of Tryptic Soy Agar), using light forward-scattering and learning algorithms (Bayes Network, Continuous Naive Bayes, Sequential Minimal Optimisation). A first database of more than 1,000 scatterograms acquired on 7 gram-negative strains yielded a recognition rate of nearly 80 %, after only 6 h of incubation. We investigated also the prospect of identifying different strains from a same species through forward scattering. We discriminated, thus, four strains of Escherichia coli with a recognition rate reaching 82 %. Finally, we show the discrimination of two species of coagulase-negative Staphylococci (S. haemolyticus and S. cohnii), on a commercial selective pre-poured medium used in clinical diagnosis (ChromID MRSA, bioMerieux), without opening lids during the scatterogram acquisition. This shows the potential of this method-non-invasive, preventing cross-contaminations and requiring minimal dish handling-to provide early clinically-relevant information in the context of fully automated microbiology labs.