IPATIMUP, Institute of Molecular Pathology and Immunology, University of Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal.
Infect Genet Evol. 2013 Jan;13:67-75. doi: 10.1016/j.meegid.2012.08.011. Epub 2012 Sep 12.
The term "complex" emerged in the literature at the beginning of the genomic era associated to taxonomy and grouping organisms that belong to different species but exhibited similar patterns according to their morphological, physiological and/or other phenotypic features. DNA-DNA hybridization values ~70% and high identity on 16S rRNA gene sequences were recommended for species delineation. Electrophoretic methods showed in some cases to be useful for species identification and population structure but the reproducibility was questionable. Later, the implementation of polyphasic approaches involving phenotypic and molecular methods brought new insights into the analysis of population structure and phylogeny of several "species complexes", allowing the identification of new closely related species. Likewise, the introduction of multilocus sequence typing and sequencing analysis of several genes offered an evolutionary perspective to the term "species complex". Several centres worldwide have recently released increasing genetic information on distinct microbial species. A brief review will be presented to highlight the definition of "species complex" for selected microorganisms, mainly the prokaryotic Acinetobacter calcoaceticus -Acinetobacter baumannii, Borrelia burgdorferi sensu lato, Burkholderia cepacia, Mycobacterium tuberculosis and Nocardia asteroides complexes, and the eukaryotic Aspergillus fumigatus, Leishmania donovani and Saccharomyces sensu stricto complexes. The members of these complexes may show distinct epidemiology, pathogenicity and susceptibility, turning critical their correct identification. Dynamics of prokaryotic and eukaryotic genomes can be very distinct and the term "species complex" should be carefully extended.
“complex”一词在基因组时代的早期文献中出现，与分类学有关，用于对属于不同物种但表现出相似形态、生理和/或其他表型特征的生物体进行分组。推荐使用 DNA-DNA 杂交值~70%和 16S rRNA 基因序列高度同源性来进行物种划分。电泳方法在某些情况下显示出对物种鉴定和种群结构的有用性，但重复性值得怀疑。后来，实施多相方法，包括表型和分子方法，为几个“物种复合体”的种群结构和系统发育分析带来了新的见解，允许鉴定新的密切相关的物种。同样，多基因座序列分型和几个基因的测序分析为“物种复合体”一词提供了进化视角。最近，全球几个中心发布了越来越多关于不同微生物物种的遗传信息。本文将简要回顾，重点介绍选定微生物的“物种复合体”定义，主要是原核生物嗜水气单胞菌-鲍曼不动杆菌、伯氏疏螺旋体、洋葱伯克霍尔德菌、结核分枝杆菌和星型诺卡氏菌复合体，以及真核生物烟曲霉、杜氏利什曼原虫和酿酒酵母复合体。这些复合体的成员可能表现出不同的流行病学、致病性和易感性，因此正确鉴定至关重要。原核生物和真核生物基因组的动态可能非常不同，因此应谨慎扩展“物种复合体”一词的使用。
