Gouveia S, Proctor M E, Lee M S, Luchansky J B, Kaspar C W
Food Research Institute, University of Wisconsin, Madison 53706-1187, USA.
J Clin Microbiol. 1998 Mar;36(3):727-33. doi: 10.1128/JCM.36.3.727-733.1998.
Contour-clamped homogeneous electric field pulsed-field gel electrophoresis (CHEF-PFGE) was used to compare Wisconsin isolates of Escherichia coli O157:H7, including 39 isolates from a 1994 day care center outbreak, 28 isolates from 18 individuals from the surrounding geographic area with sporadic cases occurring during the 3 months before the outbreak, and 3 isolates, collected in 1995, from patients with hemolytic-uremic syndrome (HUS) who were from eastern Wisconsin counties other than those inhabited by the day care center and sporadic-case individuals. The technique of CHEF-PFGE using XbaI identified seven highly related restriction endonuclease digestion profiles (REDPs) (93 to 98% similarity) among the 39 day care center isolates and nine XbaI REDPs (63 to 93% similarity) among the 28 isolates from sporadic-case individuals, including REDP 33, which was exhibited by both day care and sporadic-case isolates. PFGE analyses of sequential E. coli O157:H7 isolates from symptomatic day care center attendees revealed that the REDPs of 25 isolates from eight patients were indistinguishable whereas the REDPs of 2 of 6 isolates from two patients differed slightly (93 to 95% similarity). The REDPs of the three isolates from 1995 HUS patients were 78 to 83% similar, with REDP 26 being exhibited by one HUS-associated isolate and an isolate from one day care attendee who did not develop HUS. The genes for both Shiga toxins I and II (stx1 and stx2, respectively) were detected in all but one isolate (sporadic case), and Shiga toxin production by the day care center isolates was not significantly different from that of the other isolates, including the three HUS-associated isolates. Analyses of E. coli O157:H7 isolates from both the day care center outbreak and sporadic cases by CHEF-PFGE permitted us to define the REDP variability of an outbreak and geographic region and demonstrated that the day care center outbreak and a HUS case in 1995 were caused by E. coli O157:H7 strains endemic to eastern Wisconsin.
轮廓夹钳均匀电场脉冲场凝胶电泳（CHEF-PFGE）用于比较威斯康星州的大肠杆菌O157:H7分离株，包括1994年一家日托中心疫情中的39株分离株、疫情爆发前3个月期间周边地理区域18名散发病例患者的28株分离株，以及1995年从威斯康星州东部非日托中心和散发病例患者居住县的溶血尿毒综合征（HUS）患者中收集的3株分离株。使用XbaI的CHEF-PFGE技术在39株日托中心分离株中鉴定出7种高度相关的限制性内切酶消化图谱（REDPs）（相似度为93%至98%），在28株散发病例患者的分离株中鉴定出9种XbaI REDPs（相似度为63%至93%），包括日托中心和散发病例分离株均显示的REDP 33。对有症状的日托中心参与者的连续大肠杆菌O157:H7分离株进行PFGE分析发现，8名患者的25株分离株的REDPs无法区分，而2名患者的6株分离株中有2株的REDPs略有不同（相似度为93%至95%）。1995年HUS患者的3株分离株的REDPs相似度为78%至83%，其中一株与HUS相关的分离株和一名未患HUS的日托参与者的一株分离株显示出REDP 26。除一株分离株（散发病例）外，所有分离株均检测到志贺毒素I和II基因（分别为stx1和stx2），日托中心分离株产生的志贺毒素与其他分离株（包括3株与HUS相关的分离株）相比无显著差异。通过CHEF-PFGE对来自日托中心疫情和散发病例的大肠杆菌O157:H7分离株进行分析，使我们能够确定疫情和地理区域的REDP变异性，并证明1995年的日托中心疫情和一例HUS病例是由威斯康星州东部特有的大肠杆菌O157:H7菌株引起的。
