Department of Computer Science, School of Mathematics, Statistics and Computer Science, College of Science, University of Tehran, 14155-6455, Tehran, Iran.
Department of Microbial Biotechnology, School of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, 14155-6455, Tehran, Iran.
Sci Rep. 2019 Dec 3;9(1):18238. doi: 10.1038/s41598-019-54341-5.
The Myxococcales order consist of eleven families comprising30 genera, and are featured by the formation of the highest level of differential structure aggregations called fruiting bodies. These multicellular structures are essential for their resistance in ecosystems and is used in the primitive identification of these bacteria while their accurate taxonomic position is confirmed by the nucleotide sequence of 16SrRNA gene. Phenotypic classification of these structures is currently performed based on the stereomicroscopic observations that demand personal experience. The detailed phenotypic features of the genera with similar fruiting bodies are not readily distinctive by not particularly experienced researchers. The human examination of the fruiting bodies requires high skill and is error-prone. An image pattern analysis of schematic images of these structures conducted us to the construction of a database, which led to an extractable recognition of the unknown fruiting bodies. In this paper, Convolutional Neural Network (CNN) was considered as a baseline for recognition of fruiting bodies. In addition, to enhance the result the classifier, part of CNN is replaced with other classifiers. By employing the introduced model, all 30 genera of this order could be recognized based on stereomicroscopic images of the fruiting bodies at the genus level that not only does not urge us to amplify and sequence gene but also can be attained without preparation of microscopic slides of the vegetative cells or myxospores. The accuracy of 77.24% in recognition of genera and accuracy of 88.92% in recognition of suborders illustrate the applicability property of the proposed machine learning model.
粘球菌目包含 11 个科,30 属,其特征是形成最高水平的差异结构聚集,称为子实体。这些多细胞结构是它们在生态系统中具有抗性的关键,在原始鉴定这些细菌时被使用,而它们的准确分类地位则通过 16SrRNA 基因的核苷酸序列来确认。这些结构的表型分类目前是基于需要个人经验的立体显微镜观察来进行的。对于具有相似子实体的属的详细表型特征,即使是经验丰富的研究人员也不容易区分。对这些子实体进行人体检查需要高超的技能并且容易出错。对这些结构的示意图像进行图像模式分析,使我们构建了一个数据库,从而可以识别未知的子实体。在本文中,我们考虑使用卷积神经网络(CNN)作为识别子实体的基线。此外,为了增强分类器的结果,我们用其他分类器替换了部分 CNN。通过使用所提出的模型,我们可以根据子实体的立体显微镜图像在属水平上识别该目中的所有 30 个属,这不仅不需要我们扩增和测序基因,而且可以在不准备营养细胞或粘孢子的显微镜载玻片的情况下获得。在属识别方面的准确率为 77.24%,在亚目识别方面的准确率为 88.92%,说明了所提出的机器学习模型的适用性。