Lahti E, Keskimäki M, Rantala L, Hyvönen P, Siitonen A, Honkanen-Buzalski T
National Veterinary and Food Research Institute (EELA), P.O. Box 368, FIN-00231 Helsinki, Finland.
Vet Microbiol. 2001 Apr 2;79(3):239-51. doi: 10.1016/s0378-1135(00)00355-2.
Bovine faecal samples were collected during June-December 1997 at 14 major abattoirs slaughtering cattle in Finland. Escherichia coli O157 was isolated from 19 of the 1448 samples (1.31%) after enrichment and immunomagnetic separation (IMS). The positive faecal isolates originated from 16 farms and eight abattoirs. The occurrence of E. coli O157 was highest in July (8/204; 3.92%) and September (6/244; 2.46%). No E. coli O157 was detected in November and December, nor from the faecal samples from the northernmost region where cattle density is low. All of the isolates carried the eae gene and showed the enterohaemolytic phenotype. All except one were motile and had the flagella antigen H7. Seventeen of the isolates were positive for stx(2) gene and one carried both the stx(1) and stx(2) genes. Of the 17 isolates with stx genes, 16 were verocytotoxin-positive in a reversed passive latex agglutination test after polymyxin extraction but only eight without extraction. The isolates belonged to 10 different pulsed-field gel electrophoresis (PFGE) patterns. The most common PFGE pattern (1.42) was detected in eight isolates (42.1%). Four PFGE patterns (1.1; 1.6; 1.12; 1.14) were identical with those isolated from humans in Finland, suggesting that at least some human E. coli O157 infections may be of bovine origin.
1997年6月至12月期间，在芬兰14家主要的牛屠宰场收集了牛粪便样本。经过富集和免疫磁珠分离（IMS）后，在1448份样本中的19份（1.31%）中分离出了大肠杆菌O157。阳性粪便分离株来自16个农场和8个屠宰场。大肠杆菌O157的检出率在7月最高（8/204；3.92%），9月次之（6/244；2.46%）。11月和12月未检测到大肠杆菌O157，牛密度低的最北部地区的粪便样本中也未检测到。所有分离株都携带eae基因，并表现出肠出血性表型。除一株外，所有菌株都具有运动性，并带有鞭毛抗原H7。17株分离株stx(2)基因呈阳性，一株同时携带stx(1)和stx(2)基因。在17株携带stx基因的分离株中，16株在多粘菌素提取后的反向被动乳胶凝集试验中呈产志贺毒素阳性，但未提取的只有8株。这些分离株属于10种不同的脉冲场凝胶电泳（PFGE）图谱类型。最常见的PFGE图谱类型（1.42）在8株分离株（42.1%）中检测到。四种PFGE图谱类型（1.1；1.6；1.12；1.14）与在芬兰从人类中分离出的图谱类型相同，这表明至少一些人类大肠杆菌O157感染可能源于牛。
