Krishnan C, Fitzgerald V A, Dakin S J, Behme R J
J Clin Microbiol. 1987 Jun;25(6):1043-7. doi: 10.1128/jcm.25.6.1043-1047.1987.
A severe outbreak of hemorrhagic colitis occurred in London, Ontario, during the month of September 1985. A total of 55 residents and 18 employees of a nursing home developed diarrhea, and 17 residents (age range, 78 to 99 years) died. Specimens from 38 patients, 37 employees and contacts, and 10 autopsies were investigated for all enteric pathogens. Specimens were also planted on MacConkey-sorbitol agar. Fecal extracts were tested on Vero cells for cytotoxin (FVT). Escherichia coli isolates were serotyped and tested for verotoxin and beta-glucuronidase production. Of the 38 symptomatic patients, 26 were positive for FVT, verotoxin-producing E. coli (VTEC), or both. Of the 105 specimens that were examined from these 38 patients, FVT and VTEC were both positive in 30 specimens, FVT only was positive in 13 specimens, and VTEC only was positive in 4 specimens. None of the 27 specimens from 10 autopsies was positive for FVT or VTEC. No other enteric pathogen was found in any of the cases. All asymptomatic individuals were negative for both FVT and VTEC. Of 19 VTEC strains that were isolated, 18 belonged to serotype O157:H7. These 18 strains and 2 more strains that were obtained from sporadic cases that had occurred within the 2 previous months were found to give similar biochemical reactions in a 36-test identification system. All isolates of serotype O157:H7 were beta-glucuronidase negative and susceptible to the antimicrobial agents that are used to treat E. coli infections. Testing for FVT and VTEC was found to be the most sensitive and specific technique for the laboratory diagnosis of this disease. Negative sorbitol, positive raffinose, and negative beta-glucuronidase tests appeared to be consistent markers for aiding in the detection of E. coli O157:H7.
1985年9月，加拿大安大略省伦敦市爆发了严重的出血性结肠炎疫情。一家养老院的55名居民和18名员工出现腹泻症状，其中17名居民（年龄在78岁至99岁之间）死亡。对38名患者、37名员工及接触者的样本以及10份尸检样本进行了所有肠道病原体检测。样本还接种在麦康凯 - 山梨醇琼脂培养基上。粪便提取物在Vero细胞上检测细胞毒素（FVT）。对大肠杆菌分离株进行血清分型，并检测其产志贺毒素和β - 葡萄糖醛酸酶的能力。38名有症状的患者中，26名FVT、产志贺毒素大肠杆菌（VTEC）或两者均呈阳性。从这38名患者中检测的105份样本中，30份样本FVT和VTEC均呈阳性，13份样本仅FVT呈阳性，4份样本仅VTEC呈阳性。10份尸检的27份样本中，FVT或VTEC均为阴性。所有病例均未发现其他肠道病原体。所有无症状个体FVT和VTEC均为阴性。在分离出的19株VTEC菌株中，18株属于O157:H7血清型。这18株菌株以及从前两个月内散发病例中获得的另外2株菌株，在一个包含36项检测的鉴定系统中表现出相似的生化反应。所有O157:H7血清型分离株β - 葡萄糖醛酸酶均为阴性，且对用于治疗大肠杆菌感染的抗菌药物敏感。检测FVT和VTEC被认为是该疾病实验室诊断中最敏感和特异的技术。山梨醇阴性、棉子糖阳性和β - 葡萄糖醛酸酶阴性试验似乎是有助于检测大肠杆菌O157:H7的一致标志物。
