Bielaszewska Martina, Sonntag Anne-Katharina, Schmidt M Alexander, Karch Helge
Institute for Hygiene, and the National Consulting Laboratory on Hemolytic Uremic Syndrome, University of Münster, Robert Koch Strasse 41, D-48149 Münster, Germany.
Microbes Infect. 2007 Jun;9(7):891-7. doi: 10.1016/j.micinf.2007.03.010. Epub 2007 Mar 21.
Enterohemorrhagic Escherichia coli (EHEC) strains of serogroup O26 cause hemolytic-uremic syndrome (HUS) whereas atypical enteropathogenic E. coli (aEPEC) O26 typically cause uncomplicated diarrhea but have been also isolated from HUS patients. To gain insight into the virulence of aEPEC O26, we compared the presence of O island (OI) 122, which is associated with enhanced virulence in EHEC strains, among aEPEC O26 and EHEC O26 clinical isolates. We also tested these strains for the high pathogenicity island (HPI) which is a fitness island. All 20 aEPEC O26 and 20 EHEC O26 investigated contained virulence genes located within OI-122 (efa1/lifA, nleB, nleE, ent). In both aEPEC O26 and EHEC O26, OI-122 was linked to the locus for enterocyte effacement, forming a mosaic island which was integrated in pheU. Moreover, strains of these two pathotypes shared a conserved HPI. These data support a close relatedness between aEPEC O26 and EHEC O26 and have evolutionary implications. The presence of OI-122 in aEPEC O26 might contribute to their pathogenic potential.
血清型O26的肠出血性大肠杆菌（EHEC）菌株可导致溶血尿毒综合征（HUS），而非典型肠致病性大肠杆菌（aEPEC）O26通常引起单纯性腹泻，但也有从HUS患者中分离出来的情况。为深入了解aEPEC O26的毒力，我们比较了aEPEC O26和EHEC O26临床分离株中与EHEC菌株毒力增强相关的O岛（OI）122的存在情况。我们还检测了这些菌株是否含有作为适应性岛的高致病性岛（HPI）。所有检测的20株aEPEC O26和20株EHEC O26均含有位于OI - 122内的毒力基因（efa1/lifA、nleB、nleE、ent）。在aEPEC O26和EHEC O26中，OI - 122均与肠细胞脱落位点相连，形成一个整合于pheU中的嵌合岛。此外，这两种致病型的菌株共享一个保守的HPI。这些数据支持了aEPEC O26和EHEC O26之间的密切相关性，并具有进化意义。aEPEC O26中OI - 122的存在可能有助于其致病潜力。
