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Molecular Characterization of Maverick Strains of Enterohemorrhagic E. coli


Genetic analysis and characterization of atypical variants of E. coli O157:H7 to identify suitable target for detection method development.

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New variant strains of enterohemorrhagic Escherichia coli, particularly O157:H7, are being isolated more frequently from foods, animals and humans worldwide. Initially, these variants elude detection due to changes in the Strategy: O Rough strains of O157:H7 do not produce the O157 antigen even though they carry the genetic sequences to encode the O157 antigen. Hence, they are not detected by routine serological assays used to detect O157:H7. O rough strain will be examined to determine the absence of O antigen gene expression and develop suitable assays for detection markers targeted by current testing methods. Characterization of these variants will provide information to account for the emergence of these strains and also identify new genetic or phenotypic markers that can be used to test for these evolving pathogenic variants. This work relates directly to the objective of developing improved detection technology for emerging foodborne pathogens.

Will be developed to distinguish motility and other phenotypic variants.

The likely impact will be a more complete accounting of major hazards in the food supply, leading to a more thorough and rapid application of control measures.

Feng, Peter
DHHS/FDA - Center for Food Safety & Applied Nutrition
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