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Published on: February 3, 2015
Capture and concentration of viral and bacterial foodborne pathogens using apolipoprotein H
Erin A Almand1, Rebecca M Goulter2, Lee-Ann Jaykus3
1Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA.
Abstract:
The need for improved pathogen separation and concentration methods to reduce time-to-detection for foodborne pathogens is well recognized. Apolipoprotein H (ApoH) is an acute phase human plasma protein that has been previously shown to interact with viruses, lipopolysaccharides (LPS) and bacterial proteins. The purpose of this study was to determine if ApoH was capable of binding and efficiently capturing two representative human norovirus strains (GI.1 and GII.4), a cultivable surrogate, and four bacterial pathogens (Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica serovar Enteritidis, and Staphylococcus aureus). Experiments were carried out using an ApoH-conjugated magnetic bead-based capture followed by pathogen detection using nucleic acid amplification. For all three viruses studied, >10% capture efficiency (<1 Log10 loss in RT-qPCR amplifiable units) was observed. The same capture efficiencies were observed for the bacterial pathogens tested, with the exception of E. coli O157:H7 (approximately 1% capture efficiency, or 2 Log10 loss in CFU equivalents). The efficiency of the capture steps did not vary as a consequence of input target concentration or in the presence of an abundance of background microflora. A complementary plate-based capture assay showed that ApoH bound to a variety of human norovirus virus-like particles. ApoH has the potential to be a broadly reactive ligand for separating and concentrating representative foodborne pathogens, both bacteria and viruses.
Insights
Apolipoprotein H (ApoH) effectively captures foodborne viruses and bacteria using magnetic beads. This method shows promise for rapid pathogen detection, improving food safety diagnostics.
Area of Science:
- Food safety
- Microbiology
- Biotechnology
Background:
- Rapid detection of foodborne pathogens is crucial for public health.
- Current methods for pathogen separation and concentration can be time-consuming.
- Apolipoprotein H (ApoH) is known to interact with various microbial components.
Purpose of the Study:
- To evaluate Apolipoprotein H (ApoH) as a capture agent for foodborne pathogens.
- To determine the efficiency of ApoH in binding and concentrating human noroviruses and common bacterial pathogens.
- To assess the utility of ApoH-based capture in conjunction with nucleic acid amplification for pathogen detection.
Main Methods:
- Apolipoprotein H (ApoH) was conjugated to magnetic beads for pathogen capture.
- Capture efficiency was assessed for human norovirus strains (GI.1, GII.4), a surrogate, and bacterial pathogens (E. coli O157:H7, L. monocytogenes, S. enterica, S. aureus).
- Pathogen detection was performed using nucleic acid amplification techniques (RT-qPCR, CFU equivalents).
- A plate-based assay confirmed ApoH binding to norovirus virus-like particles.
Main Results:
- ApoH demonstrated >10% capture efficiency for all tested viruses and most bacteria (L. monocytogenes, S. enterica, S. aureus).
- Escherichia coli O157:H7 showed lower capture efficiency (~1%).
- Capture efficiency remained consistent regardless of initial pathogen concentration or presence of background microflora.
- ApoH binding to norovirus virus-like particles was confirmed.
Conclusions:
- Apolipoprotein H (ApoH) shows potential as a broadly reactive ligand for separating and concentrating diverse foodborne pathogens.
- This ApoH-based magnetic bead capture method offers a promising approach to reduce time-to-detection for foodborne pathogens.
- Further development could enhance diagnostic capabilities for food safety applications.
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