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Published on: June 16, 2020
Affinity capture of uropathogenic Escherichia coli using pigeon ovalbumin-bound Fe3O4@Al2O3 magnetic nanoparticles
Jr-Chi Liu1, Pei-Jane Tsai, Yuan C Lee
1Department of Applied Chemistry, National Chiao Tung University Hsinchu 300, Taiwan.
Abstract:
Escherichia coli and Staphylococcus saprophyticus are the most common causes of urinary tract infections, with 80% of these infections caused by uropathogenic E. coli. Because the P fimbriae of E. coli have specificity toward Gal(alpha1-4)Gal beta units, pigeon ovalbumin (POA), whose structure contains terminal Gal(alpha1-4)Gal beta moieties, was used as a probe for interaction with P fimbriated E. coli. The functional affinity probes for these bacteria by immobilizing POA--a phosphoprotein--onto the surface of magnetic iron oxide nanoparticles (NPs) coated with alumina (Fe3O4@Al2O3), using the phosphate units of POA as linking groups for the formation of phosphate-alumina complexes. The immobilization process occurred within 30 s when performing the reaction under microwave heating. The magnetic POA-Fe3O4@Al2O3 NPs generated using this facile approach exhibited specificity toward P fimbriated E. coli. The bacteria targeted by the affinity probes were characterized by matrix-assisted laser desorption/ionization mass spectrometry. The detection limit toward uropathogenic bacteria when using this approach was approximately 9.60 x 10(4) cfu/mL (0.5 mL).
Insights
Researchers developed magnetic nanoparticles coated with pigeon ovalbumin (POA) to detect P fimbriated Escherichia coli (E. coli), a common cause of urinary tract infections. This rapid method effectively targets and identifies uropathogenic bacteria.
Area of Science:
- Biotechnology
- Nanotechnology
- Microbiology
Background:
- Urinary tract infections (UTIs) are frequently caused by Escherichia coli (E. coli) and Staphylococcus saprophyticus.
- Uropathogenic E. coli strains, responsible for 80% of UTIs, possess P fimbriae that bind to Gal(alpha1-4)Gal beta units.
Purpose of the Study:
- To develop a rapid and specific affinity probe for detecting P fimbriated E. coli.
- To utilize pigeon ovalbumin (POA), a phosphoprotein with terminal Gal(alpha1-4)Gal beta moieties, as a probe for E. coli interaction.
Main Methods:
- Immobilization of POA onto magnetic iron oxide nanoparticles (Fe3O4@Al2O3) via phosphate-alumina complexes.
- Microwave heating for rapid (30 s) immobilization.
- Characterization of targeted bacteria using matrix-assisted laser desorption/ionization mass spectrometry.
Main Results:
- The developed magnetic POA-Fe3O4@Al2O3 nanoparticles demonstrated specificity for P fimbriated E. coli.
- A detection limit of approximately 9.60 x 10(4) cfu/mL was achieved for uropathogenic bacteria.
Conclusions:
- This facile approach enables the rapid and specific detection of uropathogenic E. coli using functionalized magnetic nanoparticles.
- The method shows promise for the sensitive diagnosis of UTIs caused by E. coli.
