Alocilja Magnetic Nanoparticles Efficiently Capture Escherichia coli O157:H7 Isolates

Dodge Lim, Rovi Gem Villame, Gloria June Quiñones, Dave de Vera, Rebecca Notorio, Lilia Fernando, Evangelyn Alocilja


Escherichia coli O157:H7 (EcO157) is a notorious foodborne pathogen known to cause bloody diarrhea and can even lead to death. Current detection methods, though highly sensitive, are lengthy and labor-intensive thus an alternative that is simple, rapid, low-cost and equally sensitive is necessary. Hence, an enabling method is the use of functionalized Alocilja magnetic nanoparticles (AMN), known to have high surface reactivity and can easily capture target biomolecules without the use of antibodies, such as microbial cells, in crude samples by means of a magnet. AMN, patented after its inventor Dr. Evangelyn Alocilja, is composed of iron oxide/glycan core/shell structure with an average size of 180-450 nm and with superparamagnetic properties. AMN has been reported to capture Salmonella enterica, Bacillus cereus and Mycobacterium smegmatis without the use of antibodies or peptides.


Alocilja magnetic nanoparticles, E. coli O157:H7, TEM images, cell capture

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Alocilja EC. Laboratory Research Division Brown Bag Presentation: Nanotechnology for Rapid Diagnosis of Infectious Diseases. Presented at the Research Institute for Tropical Medicine, Metro Manila, Philippines, August 25, 2017.

Alocilja EC. Development and validation of a nano-enabled self-reporting biosensor (SRB) for rapid screening of microbial agents in the food supply chain. 2016 Institute of Food Technologists Meeting, Chicago, July 16-19, 2016.

Alocilja EC, Gomez A, Sanchez H, Srivastava S, Pryg K, Vasher M, Shinners J, Murray N, Setien-Grafals M, and Fewins P. Biosensor for Rapid TB Diagnosis: One Health Paradigm. Institute of Biological Engineering Annual Meeting, St. Louis, MO, March 5-7, 2015.

Alocilja EC. Development of Biosensors for Rapid Detection and Control of Antimicrobial Resistant Infectious Pathogens. 2017 Institute of Food Technologists Meeting, Las Vegas, July 25-28, 2017.

Rundina MCN. Isolation and characterization of Shiga (Vero) Toxin-Producing Escherichia coli O157:H7 in dairy cattle (Bos Taurus) from selected farms in Luzon, Philippines. College, Laguna, Philippines: University of the Philippines, Los Baños; 2004 [master’s thesis].

Krasowska A, Sigler K. How microorganisms use hydrophobicity and what does this mean for human needs? Front Cell Infect Microbiol [Internet]. 2014 [cited 2017 Sep 22];4:112. Available from:

Xuan Y, Li Q, Hu W. Aggregation structure and thermal conductivity of nanofluids. AIChE J [Internet]. 2003;49(4):1038–43. Available from:

Boks NP, Norde W, van der Mei HC, Busscher HJ. Forces involved in bacterial adhesion to hydrophilic and hydrophobic surfaces. Microbiology [Internet]. 2008 Oct 1 [cited 2017 Sep 25];154(10):3122–33. Available from:

van Loosdrecht MCM, Lyklema J, Norde W, Zehnder AJB. Bacterial adhesion: A physicochemical approach. Microb Ecol. 1989 Jan;17(1):1–15.

van Loosdrecht MC, Lyklema J, Norde W, Schraa G, Zehnder AJ. Electrophoretic mobility and hydrophobicity as a measured to predict the initial steps of bacterial adhesion. Appl Environ Microbiol [Internet]. 1987 Aug [cited 2017 Sep 25];53(8):1898–901. Available from:

Fuente JM de la, Penadés S. Glyconanoparticles: Types, synthesis and applications in glycoscience, biomedicine and material science. Biochim Biophys Acta - Gen Subj [Internet]. 2006 Apr 1 [cited 2017 Sep 25];1760(4):636–51. Available from:


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