alexa Comparison of methods for fluorescent detection of viable, dead, and total Escherichia coli O157:H7 cells in suspensions and on apples using confocal scanning laser microscopy following treatment with sanitizers.
Veterinary Sciences

Veterinary Sciences

Journal of Veterinary Science & Technology

Author(s): Burnett SL, Beuchat LR

Abstract Share this page

Abstract The influence of treating Escherichia coli O157:H7 cells labeled with an enhanced green fluorescent protein (EGFP) plasmid with 20 microg/ml active chlorine, 100 mg/ml hydrogen peroxide, and 80 mg/ml acetic acid on fluorescence intensity was determined. In addition, fluorescent staining methods to differentiate viable and dead E. coli O157:H7 cells on the cuticle of Red Delicious cv. apples following treatment with water or 200 microg/ml active chlorine were evaluated. Suspensions of E. coli O157:H7 EGFP+ cells were exposed to chemical treatment solutions for 0, 30, 60, 120, or 300 s before populations (log10 cfu/ml) were determined by surface plating, and fluorescence intensities of suspensions and individual cells were measured using spectrofluorometry and confocal scanning laser microscopy (CSLM), respectively. The relative fluorescence intensity of suspensions and individual cells changed upon exposure to various treatments. Results indicate that the use of EGFP to tag E. coli O157:H7 may not be appropriate for investigations seeking to microscopically differentiate viable and dead cells on produce following surface treatment with sanitizers. SYTOX Orange and SYTOX Green nucleic acid stains fluorescently labeled dead E. coli O157:H7 cells attached to apple cuticles more intensely than did propidium iodide. A cross-signal occurred between CSLM photomultipliers when examining tissues treated with SYTOX Orange to detect dead cells and antibody labeled with Alexa Fluor 488 to detect total (dead and viable) cells. Because of the possibility of cross-signal resulting in an overestimation of the number of dead cells on apples and, perhaps, other produce treated with these stains, SYTOX Green is preferred to detect dead cells and antibody labeled with Alexa Fluor 594 is preferred to detect the total number of cells on apple surfaces following treatment with sanitizers. The performance of SYTOX Green in combination with Alexa Fluor 594 to detect dead and total cells of E. coli O157:H7 on other produce remains to be determined.
This article was published in Int J Food Microbiol and referenced in Journal of Veterinary Science & Technology

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri, Food, Aqua and Veterinary Science Journals

Dr. Krish

[email protected]

1-702-714-7001 Extn: 9040

Clinical and Biochemistry Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Business & Management Journals

Ronald

[email protected]

1-702-714-7001Extn: 9042

Chemical Engineering and Chemistry Journals

Gabriel Shaw

[email protected]

1-702-714-7001 Extn: 9040

Earth & Environmental Sciences

Katie Wilson

[email protected]

1-702-714-7001Extn: 9042

Engineering Journals

James Franklin

[email protected]

1-702-714-7001Extn: 9042

General Science and Health care Journals

Andrea Jason

[email protected]

1-702-714-7001Extn: 9043

Genetics and Molecular Biology Journals

Anna Melissa

[email protected]

1-702-714-7001 Extn: 9006

Immunology & Microbiology Journals

David Gorantl

[email protected]

1-702-714-7001Extn: 9014

Informatics Journals

Stephanie Skinner

[email protected]

1-702-714-7001Extn: 9039

Material Sciences Journals

Rachle Green

[email protected]

1-702-714-7001Extn: 9039

Mathematics and Physics Journals

Jim Willison

[email protected]

1-702-714-7001 Extn: 9042

Medical Journals

Nimmi Anna

[email protected]

1-702-714-7001 Extn: 9038

Neuroscience & Psychology Journals

Nathan T

[email protected]

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

John Behannon

[email protected]

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

[email protected]

1-702-714-7001 Extn: 9042

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords