Nørskov-Lauritsen Niels
Department of Clinical Microbiology, Aarhus University Hospital, Aarhus, Denmark.
Clin Microbiol Rev. 2014 Apr;27(2):214-40. doi: 10.1128/CMR.00103-13.
The aim of this review is to provide a comprehensive update on the current classification and identification of Haemophilus and Aggregatibacter species with exclusive or predominant host specificity for humans. Haemophilus influenzae and some of the other Haemophilus species are commonly encountered in the clinical microbiology laboratory and demonstrate a wide range of pathogenicity, from life-threatening invasive disease to respiratory infections to a nonpathogenic, commensal lifestyle. New species of Haemophilus have been described (Haemophilus pittmaniae and Haemophilus sputorum), and the new genus Aggregatibacter was created to accommodate some former Haemophilus and Actinobacillus species (Aggregatibacter aphrophilus, Aggregatibacter segnis, and Aggregatibacter actinomycetemcomitans). Aggregatibacter species are now a dominant etiology of infective endocarditis caused by fastidious organisms (HACEK endocarditis), and A. aphrophilus has emerged as an important cause of brain abscesses. Correct identification of Haemophilus and Aggregatibacter species based on phenotypic characterization can be challenging. It has become clear that 15 to 20% of presumptive H. influenzae isolates from the respiratory tracts of healthy individuals do not belong to this species but represent nonhemolytic variants of Haemophilus haemolyticus. Due to the limited pathogenicity of H. haemolyticus, the proportion of misidentified strains may be lower in clinical samples, but even among invasive strains, a misidentification rate of 0.5 to 2% can be found. Several methods have been investigated for differentiation of H. influenzae from its less pathogenic relatives, but a simple method for reliable discrimination is not available. With the implementation of identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry, the more rarely encountered species of Haemophilus and Aggregatibacter will increasingly be identified in clinical microbiology practice. However, identification of some strains will still be problematic, necessitating DNA sequencing of multiple housekeeping gene fragments or full-length 16S rRNA genes.
本综述的目的是全面更新目前对嗜血杆菌属和聚集杆菌属物种的分类及鉴定情况，这些物种对人类具有排他性或主要宿主特异性。流感嗜血杆菌和其他一些嗜血杆菌属物种在临床微生物实验室中较为常见，表现出广泛的致病性，从危及生命的侵袭性疾病到呼吸道感染，再到非致病性的共生生活方式。已描述了新的嗜血杆菌属物种（皮特曼嗜血杆菌和口沫嗜血杆菌），并创建了新的聚集杆菌属以容纳一些以前的嗜血杆菌属和放线杆菌属物种（嗜沫聚集杆菌、惰性聚集杆菌和伴放线聚集杆菌）。聚集杆菌属物种现在是由苛养菌引起的感染性心内膜炎（HACEK心内膜炎）的主要病因，嗜沫聚集杆菌已成为脑脓肿的重要病因。基于表型特征正确鉴定嗜血杆菌属和聚集杆菌属物种可能具有挑战性。很明显，从健康个体呼吸道分离出的推定流感嗜血杆菌菌株中有15%至20%不属于该物种，而是溶血嗜血杆菌的非溶血变体。由于溶血嗜血杆菌的致病性有限，临床样本中误鉴定菌株的比例可能较低，但即使在侵袭性菌株中，也可发现0.5%至2%的误鉴定率。已经研究了几种区分流感嗜血杆菌与其致病性较低的亲缘物种的方法，但尚无可靠鉴别的简单方法。随着基质辅助激光解吸电离飞行时间质谱鉴定方法的实施，临床微生物学实践中将越来越多地鉴定出较少见的嗜血杆菌属和聚集杆菌属物种。然而，一些菌株的鉴定仍然存在问题，需要对多个管家基因片段或全长16S rRNA基因进行DNA测序。
