Simultaneous Detection of Multifood-Borne Pathogenic Bacteria Based on Functionalized Quantum Dots Coupled with Immunomagnetic Separation in Food Samples

2009 ◽  
Vol 57 (2) ◽  
pp. 517-524 ◽  
Author(s):  
Yu Zhao ◽  
Mingqiang Ye ◽  
Qiangguo Chao ◽  
Nengqin Jia ◽  
Yu Ge ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Pathogenic Bacteria ◽  
Simultaneous Detection ◽  
Immunomagnetic Separation ◽  
Food Samples

Combination of Immunomagnetic Separation and Polymerase Chain Reaction for the Simultaneous Detection of Listeria monocytogenes and Salmonella spp. in Food Samples

2001 ◽  
Vol 64 (11) ◽  
pp. 1744-1750 ◽  
Author(s):  
HSIEN-YEE HSIH ◽  
HAU-YANG TSEN
Keyword(s):  
Polymerase Chain Reaction ◽  
Listeria Monocytogenes ◽  
Simultaneous Detection ◽  
Meat Products ◽  
Immunomagnetic Separation ◽  
Food Samples ◽  
Chain Reaction ◽  
Salmonella Spp ◽  
Pcr Method ◽  
Polymerase Chain

A method that combined the immunomagnetic separation (IMS) technique and the multiplex polymerase chain reaction (PCR) method (i.e., the IMS-mPCR method) was developed for simultaneous detection of Listeria monocytogenes and Salmonella spp. in food samples. When only the multiplex PCR method was used, it was found that if cell numbers of each of the two target organisms (L. monocytogenes and Salmonella spp.) were above the detection limit, but differed by more than 2 logs—e.g., n × 107 to n × 104 or n × 106 to n × 103—the organism presenting the lower numbers might go undetected. Following the enrichment step with universal preenrichment (UP) broth, if an IMS method using equal quantities of anti-Listeria and anti-Salmonella immunomagnetic beads was performed prior to PCR, both pathogens could be detected unambiguously. Such results could be obtained for target organisms in food samples, such as milk, dairy, and meat products, if similar enrichment and IMS steps were performed prior to PCR.

scholarly journals Detection of Escherichia coli O157:H7 Using Automated Immunomagnetic Separation and Enzyme-Based Colorimetric Assay

Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1395 ◽  
Author(s):  
Ji Young Park ◽  
Kisang Park ◽  
Gyeongsik Ok ◽  
Hyun-Joo Chang ◽  
Tae Jung Park ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
Enzymatic Reaction ◽  
Immunomagnetic Separation ◽  
Food Samples ◽  
Detection Methods ◽  
Immunomagnetic Beads ◽  
E Coli ◽  
Chlorophenol Red

The food industry requires rapid and simple detection methods for preventing harm from pathogenic bacteria. Until now, various technologies used to detect foodborne bacteria were time-consuming and laborious. Therefore, we have developed an automated immunomagnetic separation combined with a colorimetric assay for the rapid detection of E. coli O157:H7 in food samples. The colorimetric detection method using enzymatic reaction is fascinating because of its simplicity and rapidity and does not need sophisticated devices. Moreover, the proposed procedures for the detection of bacteria in food take less than 3 h including pre-enrichment, separation and detection steps. First, target-specific immunomagnetic beads were introduced to contaminated milk in a pre-enrichment step. Second, the pre-enriched sample solution containing target bacteria bound on immunomagnetic beads was injected into an automated pretreatment system. Subsequently, the immunomagnetic beads along with target bacteria were separated and concentrated into a recovery tube. Finally, released β-galactosidase from E. coli O157:H7 after lysis was reacted with chlorophenol red β-galactopyranoside (CPRG) used as a substrate and the colorimetric change of CPRG was determined by absorbance measuring or the naked eye. By the proposed approach in this study, we could detect 3 × 102 CFU/mL of E. coli O157:H7 from a milk sample within 3 h.

Rapid Detection of Norovirus from Fresh Lettuce Using Immunomagnetic Separation and a Quantum Dots Assay

2013 ◽  
Vol 76 (4) ◽  
pp. 707-711 ◽  
Author(s):  
HEE-MIN LEE ◽  
JOSEPH KWON ◽  
JONG-SOON CHOI ◽  
KYEONG-HWAN LEE ◽  
SUNG YANG ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Speed ◽  
Virus Detection ◽  
Immunomagnetic Separation ◽  
Food Samples ◽  
Pcr Analysis ◽  
Virus Concentration ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Centrifugation Step

Current molecular methods that include PCR have been used to detect norovirus in many food samples. However, the protocols require removing PCR inhibitors and incorporate time-consuming concentration steps to separate virus from analyte for rapid and sensitive detection of norovirus. We developed an immunomagnetic separation (IMS) and a quantum dots (QDs) assay to detect norovirus eluted from fresh lettuce with Tris buffer containing 1% beef extract (pH 9.5). IMS facilitated viral precipitation with a 10-min incubation, whereas virus concentration using polyethylene glycol (PEG) requires more than 3 h and an additional high-speed centrifugation step to precipitate virus before reverse transcription PCR (RT-PCR) analysis. The fluorescence intensity of QDs was detected qualitatively on norovirus dilutions of 10−1 to 10−3 in a stool suspension (100 RT-PCR units/ml). The results suggest that a fluorescence assay based on IMS and QDs is valid for detecting norovirus qualitatively according to fluorescent signal intensity within the same virus detection limit produced by IMS–RT-PCR and PEG–RT-PCR.

Rapid, Sensitive, and Simultaneous Detection of Three Foodborne Pathogens Using Magnetic Nanobead–Based Immunoseparation and Quantum Dot–Based Multiplex Immunoassay

2011 ◽  
Vol 74 (12) ◽  
pp. 2039-2047 ◽  
Author(s):  
HONG WANG ◽  
YANBIN LI ◽  
ANDREW WANG ◽  
MICHAEL SLAVIK
Keyword(s):  
Salmonella Typhimurium ◽  
Fluorescence Intensity ◽  
Foodborne Pathogens ◽  
Pathogenic Bacteria ◽  
Human Life ◽  
Simultaneous Detection ◽  
Food Product ◽  
Food Samples ◽  
Multiplex Immunoassay ◽  
E Coli

Losses caused by foodborne diseases are enormous in terms of human life, illness, medical costs, and food product recalls. Rapid detection of multiple bacterial pathogens in foods is extremely important to ensure food safety. The objective of this research was to develop a multiplex immunoassay by integrating magnetic nanobeads (MNBs) for immunoseparation with quantum dots (QDs) as fluorescent labels for rapid, sensitive, and simultaneous detection of three major pathogenic bacteria, Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes, in food products. In this research, both streptavidin-conjugated MNBs (30- and 150-nm diameter) and QDs (530-, 580-, and 620-nm emission wavelength) were separately coated with biotinylated anti-Salmonella, anti–E. coli, and anti-Listeria antibodies. The immuno-MNBs were mixed with a food sample to capture the three target bacteria. After being magnetically separated from the sample, the MNB-cell conjugates were mixed with the immuno-QDs to form the MNB-cell-QD complexes, and unattached QDs were removed. The fluorescence intensity of the MNB-cell-QD complexes was measured at wavelengths of 530, 580, and 620 nm to determine the populations of Salmonella Typhimurium, E. coli O157:H7, and L. monocytogenes, respectively. This multiplex immunoassay simultaneously detected Salmonella Typhimurium, E. coli O157:H7, and L. monocytogenes at levels as low as 20 to 50 CFU/ml in food samples in less than 2 h without enrichment. The change in fluorescence intensity was linearly correlated (R2 > 0.96) with the logarithmic value of bacterial level in the range of 10 to 103 CFU/ml. More than 85% of the three target pathogens could be simultaneously separated from food samples. The multiplex immunoassay could be expanded to detect more target pathogens, depending on the availability of specific antibodies and QDs with different emission wavelengths.

A Review on Quantum Dots: Synthesis to In- silico Analysis as Next Generation Antibacterial Agents

2019 ◽  
Vol 20 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Sounik Manna ◽  
Munmun Ghosh ◽  
Ranadhir Chakraborty ◽  
Sudipto Ghosh ◽  
Santi M. Mandal
Keyword(s):  
Quantum Dots ◽  
Pathogenic Bacteria ◽  
Antibacterial Agents ◽  
Antimicrobial Properties ◽  
Binding Potential ◽  
Antibacterial Drug ◽  
Next Generation ◽  
Mechanism Of Reaction ◽  
High Level ◽  
Membrane Components

Succumbing to Multi-Drug Resistant (MDR) bacteria is a great distress to the recent health care system. Out of the several attempts that have been made to kill MDR pathogens, a few gained short-lived success. The failures, of the discovered or innovated antimicrobials, were mostly due to their high level of toxicity to hosts and the phenomenal rate of developing resistance by the pathogens against the new arsenal. Recently, a few quantum dots were tested against the pathogenic bacteria and therefore, justified for potential stockpiling of next-generation antibacterial agents. The key players for antimicrobial properties of quantum dots are considered to be Reactive Oxygen Species (ROS). The mechanism of reaction between bacteria and quantum dots needs to be better understood. They are generally targeted towards the cell wall and membrane components as lipoteichoic acid and phosphatidyl glycerol of bacteria have been documented here. In this paper, we have attempted to simulate ZnS quantum dots and have analysed their mechanism of reaction as well as binding potential to the above bacterial membrane components using CDOCKER. Results have shown a high level of antibacterial activity towards several pathogenic bacteria which specify their potentiality for future generation antibacterial drug development.

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