Cattoir Vincent, Lemenand Olivier, Avril Jean-Loup, Gaillot Olivier
Laboratoire de Bactériologie-Virologie, Faculté de Médecine, Université de Rennes 1, F-35034 Rennes, France.
Int J Med Microbiol. 2006 Dec;296(8):531-40. doi: 10.1016/j.ijmm.2006.06.005.
The genus Haemophilus constitutes a heterogeneous group of Pasteurellaceae species, and conventional identification of isolates other than Haemophilus influenzae and Haemophilus parainfluenzae is often challenging. Here, simple colony-PCR and sequencing assays with the same pair of degenerate primers were used to characterize a 449- to 458-bp fragment (sodA(int)) internal to the sodA gene encoding the manganese-dependent superoxide dismutase in type strains of all 15 Haemophilus species and Actinobacillus actinomycetemcomitans. The topology of a sodA(int)-based phylogenetic tree was in general agreement with that inferred from the analysis of 16S rRNA and other housekeeping gene sequences, but allowed more confident delineation of the main clusters of species. The sodA(int) sequences showed a markedly higher divergence than those of the corresponding 16S rRNA genes, and 38 independent human clinical isolates were identified by comparing their sodA(int) sequence to those of the type species. Except for one Haemophilus aphrophilus strain, all isolates were unambiguously characterized in spite of a high intraspecific sodA(int) sequence diversity. This study provides a comprehensive sequence-based phylogenetic analysis of the entire genus Haemophilus, and confirms that sodA is a potent target for the identification of clinical isolates of Pasteurellaceae. This approach might contribute to the taxonomic reappraisal of this family, and to the development of diagnostic tools.
嗜血杆菌属是巴斯德菌科中一组异质的菌种，除流感嗜血杆菌和副流感嗜血杆菌外，对其他分离株进行常规鉴定往往具有挑战性。在此，我们使用简单的菌落PCR和测序分析，用同一对简并引物对所有15种嗜血杆菌属菌种和伴放线放线杆菌的模式菌株中编码锰依赖性超氧化物歧化酶的sodA基因内部的一段449至458bp的片段（sodA(int)）进行了特征分析。基于sodA(int)构建的系统发育树的拓扑结构总体上与从16S rRNA和其他管家基因序列分析推断出的结构一致，但能更可靠地划分主要的菌种簇。sodA(int)序列的差异明显高于相应的16S rRNA基因，通过将38株独立的人类临床分离株的sodA(int)序列与模式菌种的序列进行比较，对它们进行了鉴定。除了一株嗜沫嗜血杆菌菌株外，尽管种内sodA(int)序列存在高度多样性，但所有分离株都得到了明确的鉴定。本研究提供了对整个嗜血杆菌属基于序列的全面系统发育分析，并证实sodA是鉴定巴斯德菌科临床分离株的有效靶点。这种方法可能有助于对该科进行分类学重新评估，并有助于开发诊断工具。
