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目的 探讨我国部分地区产生志贺毒素的肠出血性大肠埃希菌 (EHEC)O15 7∶H7菌株的分布、流行以及分型情况。方法 用脉冲电场凝胶电泳 (PFGE)方法进行分型 ,辅以药物敏感性试验对 5 1株产生志贺毒素的EHECO15 7∶H7菌株进行研究。结果 根据细菌染色体DNA的XbaI酶切图谱 ,可将从江苏省徐州市等地分离的 5 1株产生志贺毒素的EHECO15 7∶H7菌株分成 8个PFGE型别 (PFGE1～PFGE8) ,宁夏菌株为PFGE1型和 2型 ,徐州菌株有 6个PFGE型。 1986～ 1988年的分离菌株属于PFGE7型 ,1999、2 0 0 0年病人分离株的优势型别分别是PFGE5型与 3型。 1999年爆发性流行期间从患者分离的 5株菌属于PFGE 5型 ,从家畜家禽的粪便、食品、蔬菜等标本分离的 19株菌 ,可以分为PFGE3～ 6等 4个型别 ,其中 ,PFGE5型占优势 (10株菌 )。结论 爆发性流行的发生与携带病原菌的家畜家禽粪便污染的食品、蔬菜等有关 ,从我国部分地区分离的EHECO15 7∶H7菌株的PFGE型别有地区性差异
Objective To investigate the distribution, epidemiology and typing of enterohemorrhagic Escherichia coli (EHEC) O15 7:H7 producing Shiga toxin in some areas in China. Methods Pulsed-field gel electrophoresis (PFGE) was used to genotype 51 strains of EHECO15 7:H7 strains, which were induced by Shiga toxin in combination with drug susceptibility test. Results According to the XbaI digestion map of bacterial chromosomal DNA, 51 strains of Shiga toxin-producing EHECO15 7:H7 isolates from Xuzhou City of Jiangsu Province were divided into 8 PFGE types (PFGE1 to PFGE8). Ningxia strain was PFGE1 type and 2 type, Xuzhou strain has 6 PFGE type. The isolates from 1986 to 1988 belonged to PFGE7. The predominant strains of patient isolates from 1999 to 2000 were PFGE5 and 3, respectively. Five strains isolated from patients during the outbreak in 1999 were classified as PFGE 5 type. Nineteen strains isolated from samples of livestock and poultry such as feces, food and vegetables were classified into 4 genotypes, PFGE5 and PFGE5 Type dominant (10 strains). Conclusions The occurrence of the outbreak is related to the contamination of foodstuffs and vegetables by livestock poultry excrement with pathogenic bacteria. The PFGE types of EHECO15 7:H7 isolates isolated from some areas of China have regional differences