Rectoanal junction colonization of feedlot cattle by Escherichia coli O157:H7 and its association with supershedders and excretion dynamics
Rectoanal junction colonization of feedlot cattle by Escherichia coli O157:H7 and its association with supershedders and excretion dynamics
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DOI：
10.1128/aem.01742-06
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发表时间：
2007-03-01
影响因子：
4.4
通讯作者：
Besser, Thomas E.
中科院分区：
文献类型：
--
作者：
Cobbold, Rowland N.;Hancock, Dale D.;Besser, Thomas E.
观察饲养场牛的粪便排泄和直肠肛门连接处（RAJ）大肠杆菌O 157：H7定植，以确定潜在的“超级散毒体”。“RAJ定植和粪便排泄患病率是相关的，E.大肠杆菌O 157：H7的患病率和计数在RAJ样品中显著更高。通过比较E. coliO157：H7/E.大肠杆菌计数，RAJ似乎是由O 157：H7血清型优先定殖。根据高浓度E. coli O157：H7。用超级脱毛器饲养的牛具有显著更大的平均围栏E。大肠杆菌O 157：H7 RAJ和粪便中的感染率高于未断奶牛。累积粪便E.大肠杆菌O 157：H7排泄也显着较高的围栏住房的supershedder。E. coliO157：H7/E.大肠杆菌计数比率在超级散毒牛中高于其他牛，表明更大比例的定植。脉冲场凝胶电泳分析表明，从超级脱落和断奶牛的菌株高度相关。对E.大肠杆菌O 157：H7在整个采样的五倍更有可能已经在一个围栏，没有房子一个超级脱落。这项研究的数据支持粪便排泄E。大肠杆菌O 157：H7和RAJ定植在围栏的饲养场牛，并建议存在的supershedders影响组水平的排泄参数。提高对E.大肠杆菌O 157：H7可用于开发屠宰前和屠宰水平的干预措施，以减少食物链的污染。
Feedlot cattle were observed for fecal excretion of and rectoanal junction (RAJ) colonization with Escherichia coli O157:H7 to identify potential "supershedders." RAJ colonization and fecal excretion prevalences were correlated, and E. coli O157:H7 prevalences and counts were significantly greater for RAJ samples. Based on a comparison of RAJ and fecal ratios of E. coli O157:H7/E. coli counts, the RAJ appears to be preferentially colonized by the O157:H7 serotype. Five supershedders were identified based on persistent colonization with high concentrations of E. coli O157:H7. Cattle copenned with supershedders had significantly greater mean pen E. coli O157:H7 RAJ and fecal prevalences than noncopenned cattle. Cumulative fecal E. coli O157:H7 excretion was also significantly higher for pens housing a supershedder. E. coli O157:H7/E. coli count ratios were higher for supershedders than for other cattle, indicating greater proportional colonization. Pulsed-field gel electrophoresis analysis demonstrated that isolates from supershedders and copenned cattle were highly related. Cattle that remained negative for E. coli O157:H7 throughout sampling were five times more likely to have been in a pen that did not house a supershedder. The data from this study support an association between levels of fecal excretion of E. coli O157:H7 and RAJ colonization in pens of feedlot cattle and suggest that the presence of supershedders influences group-level excretion parameters. An improved understanding of individual and population transmission dynamics of E. coli O157:H7 can be used to develop preslaughter- and slaughter-level interventions that reduce contamination of the food chain.