کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5545130 | 1555322 | 2017 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Use of signature-tagged mutagenesis to identify genes associated with colonization of sheep by E. coli O157:H7
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موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
علوم دامی و جانورشناسی
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چکیده انگلیسی
Outbreaks of Escherichia coli O157:H7 in the United States due to contaminated foods are a public health issue and a continuing problem. The major reservoir for these organisms is the gastrointestinal tract of ruminants where they are a member of the resident microbiota. Several factors that contribute to the colonization of cattle have been identified, but a systematic screen of genes that might contribute to the colonization and persistence phenotype in mature ruminants has not been reported. Using a sheep model of persistence, signature tagged mutagenesis (STM) was used to screen 1326 mutants for a persistence-negative phenotype of E. coli O157:H7. We identified 9 genes by STM that appeared to be required for colonization and/or survival in sheep. Three of the genes had functions associated with central metabolism (thiK, ftrA and nrdB), one was involved with LPS formation (wbdP), one encodes a non-LEE encoded effector protein (nleB) and one was a methyltransferase encoded on a prophage (Z2389). The remaining three genes did not have homology with any known genes. Six sheep given ÎwbdP and 2 sheep each were given mutants (ÎthiK (Z1745), ÎftrA (Z2164) and Z2389). The ÎwbdP mutant was recovered from the feces of 4/6 sheep at 6 days pi with a mean number of 1.42Â log10Â CFU/g feces compared to 4.6Â log10Â CFU/g feces for the wild type strain. This difference was significant (PÂ <Â 0.001) over the time course of the experiment (days 6-23). Both ÎthiK and ÎftrA mutants were recovered from 1 of 2 sheep at 9 days PI by enrichment procedures (<50Â CFU/g feces) whereas mutant Z2389 was not recovered from either animal past 2 days pi. The roles of all of these gene products require further study to determine how the persistence phenotype of a given strain of E. coli O157:H7 interacts with host factors.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Veterinary Microbiology - Volume 201, March 2017, Pages 177-182
Journal: Veterinary Microbiology - Volume 201, March 2017, Pages 177-182
نویسندگان
Nancy A. Cornick, Josh Pitzer, Amy F. Helgerson, Melissa L. Madsen, Kathy T. Kurth, Qianjun Xiao, F. Chris Minion,