Johnson James R, Kuskowski Michael A, Smith Kirk, O'Bryan Timothy T, Tatini Sita
Mucosal and Vaccine Research Center, Veterans Affairs Medical Center, and Department of Medicine, University of Minnesota, Minneapolis, Minnesota 55417, USA.
J Infect Dis. 2005 Apr 1;191(7):1040-9. doi: 10.1086/428451. Epub 2005 Mar 1.
Extraintestinal Escherichia coli infections are associated with specialized extraintestinal pathogenic E. coli (ExPEC) strains and, increasingly, with antimicrobial resistance. The food supply may disseminate ExPEC and antimicrobial-resistant E. coli.
In a prospective survey of 1648 diverse food items from 10 retail markets in the Minneapolis-St. Paul area during 2001-2003, selective cultures and disk-diffusion assays for the isolation and characterization of antimicrobial-resistant E. coli and polymerase chain reaction-based assays and O serotyping to define ExPEC-associated traits were performed.
E. coli contamination exhibited a prevalence gradient from miscellaneous foods (9%), through beef or pork (69%), to poultry (92%; P<.001). Among E. coli-positive samples, similar prevalence gradients were detected for antimicrobial resistance (27%, 85%, and 94% of samples, respectively; P<.001) and ExPEC contamination (4%, 19%, and 46%, respectively; P<.001). By multivariate analysis, beef or pork and poultry from natural-food stores exhibited reduced risks of E. coli contamination and antimicrobial resistance. Indirect evidence suggested on-farm selection of resistance. Four food-source ExPEC isolates (from pea pods, turkey parts, ground pork, and vegetable dip) closely resembled selected human clinical isolates by O antigen and genomic profile.
Retail foods may be an important vehicle for community-wide dissemination of antimicrobial-resistant E. coli and ExPEC, which may represent a newly recognized group of medically significant foodborne pathogens.
肠外大肠杆菌感染与特殊的肠外致病性大肠杆菌（ExPEC）菌株相关，并且越来越多地与抗菌药物耐药性有关。食品供应可能会传播ExPEC和耐药性大肠杆菌。
在2001年至2003年期间对明尼阿波利斯 - 圣保罗地区10个零售市场的1648种不同食品进行的前瞻性调查中，进行了选择性培养和纸片扩散试验，以分离和鉴定耐药性大肠杆菌，并进行基于聚合酶链反应的试验和O血清分型以确定与ExPEC相关的特征。
大肠杆菌污染呈现出一个患病率梯度，从杂类食品（9%），到牛肉或猪肉（69%），再到家禽（92%；P<0.001）。在大肠杆菌阳性样本中，抗菌药物耐药性（分别为样本的27%、85%和94%；P<0.001）和ExPEC污染（分别为4%、19%和46%；P<0.001）也检测到类似的患病率梯度。通过多变量分析，天然食品店的牛肉或猪肉以及家禽的大肠杆菌污染和抗菌药物耐药性风险降低。间接证据表明在农场进行了耐药性选择。四个食品源ExPEC分离株（来自豌豆荚、火鸡部位、绞猪肉和蔬菜蘸酱）在O抗原和基因组图谱方面与选定的人类临床分离株非常相似。
零售食品可能是社区范围内传播耐药性大肠杆菌和ExPEC的重要载体，这可能代表了一组新认识的具有医学意义的食源性病原体。
