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Xuan Weng

Publications and source records attributed to Xuan Weng.

2 recordsLinked to original sources

Investigation of the Antimicrobial Activity of Soy Peptides by Developing a High Throughput Drug Screening Assay

BackgroundAntimicrobial resistance is a great concern in the medical community, as well as food industry. Soy peptides were tested against bacterial biofilms for their antimicrobial activity. A high throughput drug screening assay was developed using microfluidic technology, RAMAN spectroscopy, and optical microscopy for rapid screening of antimicrobials and rapid identification of pathogens.\n\nMethodsSynthesized PGTAVFK and IKAFKEATKVDKVVVLWTA soy peptides were tested against Pseudomonas aeruginosa and Listeria monocytogenes using a microdilution assay. Microfluidic technology in combination with Surface Enhanced RAMAN Spectroscopy (SERS) and optical microscopy was used for rapid screening of soy peptides, pathogen identification, and to visualize the impact of selected peptides.\n\nResultsThe PGTAVFK peptide did not significantly affect P. aeruginosa, although it had an inhibitory effect on L. monocytogenes above a concentration of 625 {micro}M. IKAFKEATKVDKVVVLWTA was effective against both P. aeruginosa and L. monocytogenes above a concentration of 37.2 {micro}M. High throughput drug screening assays were able to reduce the screening and bacterial detection time to 4 h. SERS spectra was used to distinguish the two bacterial species.\n\nConclusionsPGTAVFK and IKAFKEATKVDKVVVLWTA soy peptides showed antimicrobial activity against P. aeruginosa and L. monocytogenes. Development of high throughput assays could streamline the drug screening and bacterial detection process. General significance: The results of this study show that the antimicrobial properties, biocompatibility, and biodegradability of soy peptides could possibly make them an alternative to the ineffective antimicrobials and antibiotics currently used in the food and medical fields. High throughput drug screening assays could help hasten pre-clinical trials in the medical field.

Bioengineering

Single cell chemotactic responses of Helicobacter pylori to urea in a microfluidic chip

Helicobacter pylori is a spiral-shaped bacterium that grows in the human digestive tract; it infects ~50% of the global population. H. pylori induce inflammation, gastroenteritis, and ulcers, which is associated with significant morbidity and may be linked to stomach cancer in certain individuals. Motility is an essential virulence factor for H. pylori, allowing it to migrate toward and invade the epithelial lining of the stomach to shelter it from the harsh environment of the stomach. H. pylori senses pH gradients and use polar flagella to move towards the epithelium where the pH approaches neutrality. However, its chemotaxis behaviors are incompletely understood. Previous in vitro tests examining the response of H. pylori to chemical gradients have been subjected to substantial limitations. To more accurately mimic/modulate the cellular microenvironment, a nanoporous microfluidic device was used to monitor the real time chemotactic activity of single cell of H. pylori in response to urea. The results showed that microfluidic method is a promising alternative for precisely studying chemotactic behavior of bacteria.

Bioengineering