Facultad de Medicina-Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, 04510 México D.F.
Can J Microbiol. 2011 Sep;57(9):735-44. doi: 10.1139/w11-063. Epub 2011 Aug 22.
Cronobacter spp. ( Enterobacter sakazakii ) includes gram-negative opportunistic foodborne pathogens known as rare but important causes of life-threatening neonatal infections. However, the pathogenic mechanism is not yet clear. In this study, 43 isolates of Cronobacter, from human and nonhuman sources, were analyzed. A total of four clusters were identified and 32 DNA pulsotypes were observed by pulsed-field gel electrophoresis. In addition, 86% of the Cronobacter isolates were able to adhere to HEp-2 cells and 35% were invasive, Cronobacter sakazakii isolates being the most efficient. Twenty-six percent of Cronobacter isolates were able to form biofilms, mainly those from nonhuman sources, such as Cronobacter dublinensis and Cronobacter malonaticus . Three putative virulence genes (siderophore-interacting protein (sip), type III hemolysin (hly), and plasminogen activator (cpa)) were identified by bioinformatic analysis and then detected by PCR. The sip gene was the most frequently detected (60%; 26/43), followed by the hly gene (37%; 16/43) and the cpa gene (28%; 12/43). The three genes were identified primarily in C. sakazakii. Our data show that Cronobacter species harbor different virulence traits.
阪崎克罗诺杆菌（Cronobacter spp.）（肠杆菌科沙雷氏菌）属于革兰氏阴性机会致病菌，是罕见但重要的食源性致病菌，可导致危及生命的新生儿感染。然而，其发病机制尚不清楚。本研究对 43 株人源和非人生源的阪崎克罗诺杆菌进行了分析。通过脉冲场凝胶电泳共鉴定出 4 个克隆群，观察到 32 个 DNA 脉冲型。此外，86%的阪崎克罗诺杆菌能够黏附 HEp-2 细胞，35%能够侵袭，其中以阪崎克罗诺杆菌的侵袭能力最强。26%的阪崎克罗诺杆菌能够形成生物膜，主要是来自非人生源的菌株，如都柏林克罗诺杆菌和马尔他克罗诺杆菌。通过生物信息学分析鉴定了 3 个假定的毒力基因（铁载体相互作用蛋白（sip）、III 型溶血素（hly）和纤溶酶原激活剂（cpa）），然后通过 PCR 进行了检测。sip 基因的检出率最高（60%，26/43），其次是 hly 基因（37%，16/43）和 cpa 基因（28%，12/43）。这 3 个基因主要存在于阪崎克罗诺杆菌中。本研究数据表明，阪崎克罗诺杆菌具有不同的毒力特征。
