Centres for Food Safety and Foodborne Zoonomics, School of Agriculture, Food Science, and Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland.
Foodborne Pathog Dis. 2010 Apr;7(4):339-50. doi: 10.1089/fpd.2009.0379.
Cronobacter spp. (Enterobacter sakazakii) are a recently described genus that is comprised of six genomospecies. The classification of these organisms was revised based on a detailed polyphasic taxonomic study. Cronobacter spp. are regarded as ubiquitous organisms having been isolated from a wide variety of foods. These bacteria are opportunistic pathogens and are linked with life-threatening infections in neonates. Clinical symptoms of Cronobacter infection include necrotizing enterocolitis, bacteremia, and meningitis, with case fatality rates of 50-80% being reported. Contaminated powdered infant formula has been epidemiologically linked with infections. Recently, infections among immunocompromised adults, mainly the elderly, have also been reported. A high tolerance to osmotic stress and elevated temperatures contribute to the survival of Cronobacter spp. in dried foods such as powdered infant formula. Controlling the organism in the production environment, thereby reducing dissemination, necessitates the provision of suitable diagnostic tools. Studies demonstrated that a high degree of variability exists amongst the phenotypic-based methods used to identify Cronobacter spp. However, advances in molecular detection and subtyping techniques have significantly improved the identification and characterization of Cronobacter spp. The dose required to induce infection has yet to be determined. In vitro virulence studies have shown that Cronobacter spp. may survive in macrophage cells and efficiently attach to and invade epithelial cell lines. The production of exopolysaccharide may contribute to the formation of biofilm and active efflux pumps promote resistance to antimicrobial agents such as bile salts and disinfectants. A holistic approach combining techniques such as comparative genome analysis, proteomics, and in vivo challenges could help unravel the complex interactions between this pathogen and its host. These data would help identify those properties in Cronobacter spp. which enable the bacterium to survive in the production environment and infect vulnerable neonates via the food chain.
克罗诺杆菌属（阪崎肠杆菌）是最近描述的一个属，由六个基因组种组成。这些生物体的分类是根据详细的多相分类学研究修订的。克罗诺杆菌属被认为是普遍存在的生物体，已从各种食物中分离出来。这些细菌是机会性病原体，与新生儿的危及生命的感染有关。克罗诺杆菌感染的临床症状包括坏死性小肠结肠炎、菌血症和脑膜炎，报告的病死率为 50-80%。受污染的配方奶粉已在流行病学上与感染有关。最近，免疫功能低下的成年人（主要是老年人）也报告了感染。对渗透压应激和高温的高耐受性有助于克罗诺杆菌属在干燥食品（如配方奶粉）中存活。在生产环境中控制该生物体，从而减少传播，需要提供合适的诊断工具。研究表明，用于鉴定克罗诺杆菌属的基于表型的方法存在很大的可变性。然而，分子检测和分型技术的进步显著提高了克罗诺杆菌属的鉴定和特征描述。诱导感染所需的剂量尚未确定。体外毒力研究表明，克罗诺杆菌属可能在巨噬细胞中存活，并有效地附着和侵袭上皮细胞系。胞外多糖的产生可能有助于生物膜的形成，主动外排泵促进对胆盐和消毒剂等抗菌剂的耐药性。结合比较基因组分析、蛋白质组学和体内挑战等技术的整体方法可以帮助揭示这种病原体与其宿主之间的复杂相互作用。这些数据将有助于确定克罗诺杆菌属中使细菌能够在生产环境中存活并通过食物链感染脆弱新生儿的特性。
