title: High-throughput detection of food-borne pathogenic bacteria using oligonucleotide microarray with quantum dots as fluorescent labels.
abstract: Bacterial pathogens are mostly responsible for food-borne diseases, and there is still substantial room for improvement in the effective detection of these organisms. In the present study, we explored a new method to detect target pathogens easily and rapidly with high sensitivity and specificity. This method uses an oligonucleotide microarray combined with quantum dots as fluorescent labels. Oligonucleotide probes targeting the 16SrRNA gene were synthesized to create an oligonucleotide microarray. The PCR products labeled with biotin were subsequently hybridized using an oligonucleotide microarray. Following incubation with CdSe/ZnS quantum dots coated with streptavidin, fluorescent signals were detected with a PerkinElmer Gx Microarray Scanner. The results clearly showed specific hybridization profiles corresponding to the bacterial species assessed. Two hundred and sixteen strains of food-borne bacterial pathogens, including standard strains and isolated strains from food samples, were used to test the specificity, stability, and sensitivity of the microarray system. We found that the oligonucleotide microarray combined with quantum dots used as fluorescent labels can successfully discriminate the bacterial organisms at the genera or species level, with high specificity and stability as well as a sensitivity of 10 colony forming units (CFU)/mL of pure culture. We further tested 105 mock-contaminated food samples and achieved consistent results as those obtained from traditional biochemical methods. Together, these results indicate that the quantum dot-based oligonucleotide microarray has the potential to be a powerful tool in the detection and identification of pathogenic bacteria in foods.
authors.affiliation: Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment and Food Safety, Institute of Health and Environmental Medicine, Tianjin, 300050, P. R. China; Logistics College of Chinese People's Armed Police Forces, Tianjin, 300162, P. R. China.
authors.forename: Aihua
authors.initials: A
authors.lastname: Huang
authors.affiliation: Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment and Food Safety, Institute of Health and Environmental Medicine, Tianjin, 300050, P. R. China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Qiu
authors.affiliation: Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment and Food Safety, Institute of Health and Environmental Medicine, Tianjin, 300050, P. R. China.
authors.forename: Min
authors.initials: M
authors.lastname: Jin
authors.affiliation: Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment and Food Safety, Institute of Health and Environmental Medicine, Tianjin, 300050, P. R. China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Shen
authors.affiliation: Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment and Food Safety, Institute of Health and Environmental Medicine, Tianjin, 300050, P. R. China.
authors.forename: Zhaoli
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment and Food Safety, Institute of Health and Environmental Medicine, Tianjin, 300050, P. R. China.
authors.forename: Xinwei
authors.initials: X
authors.lastname: Wang
authors.affiliation: Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment and Food Safety, Institute of Health and Environmental Medicine, Tianjin, 300050, P. R. China. Electronic address: junwen9999@hotmail.com.
authors.forename: Jun-Wen
authors.initials: JW
authors.lastname: Li
mesh_terms: D001419:Bacteria / Q000302:isolation & purification*; D005516:Food Microbiology / Q000295:instrumentation* / Q000379:methods*; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D015345:Oligonucleotide Probes / Q000235:genetics; D016133:Polymerase Chain Reaction; D045663:Quantum Dots; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012680:Sensitivity and Specificity
chemical_list: D015345:Oligonucleotide Probes; D012336:RNA, Ribosomal, 16S
keywords: Bacteria; Detection; Hybridization; Microarray; Probes; Quantum dots