title: Rapid identification and classification of Campylobacter spp. using laser optical scattering technology.
abstract: Campylobacter jejuni and Campylobacter coli are the two important species responsible for most of the Campylobacter infections in humans. Reliable isolation and detection of Campylobacter spp. from food samples are challenging due to the interferences from complex food substances and the fastidious growth requirements of this organism. In this study, a novel biosensor-based detection called BARDOT (BActerial Rapid Detection using Optical scattering Technology) was developed for high-throughput screening of Campylobacter colonies grown on an agar plate without disrupting the intact colonies. Image pattern characterization and principal component analysis (PCA) of 6909 bacterial colonies showed that the light scatter patterns of C. jejuni and C. coli were strikingly different from those of Salmonella spp., Escherichia coli O157:H7, and Listeria monocytogenes. Examination of a mixed culture of these microorganisms revealed 85% (34/40) accuracy in differentiating Campylobacter from the other three major foodborne pathogens based on the similarity to the scatter patterns in an established library. The application of BARDOT in real food has been addressed through the analysis of Campylobacter spiked ground chicken and naturally contaminated fresh chicken pieces. Combined with real-time PCR verification, BARDOT was able to identify Campylobacter isolates from retail chicken. Moreover, applying passive filtration to food samples facilitated the isolation of pure Campylobacter colonies and therefore overcame the interference of the food matrix on BARDOT analysis.
authors.affiliation: Molecular Characterization of Foodborne Pathogens Research Unit, US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center (USDA-ARS-ERRC), 600 East Mermaid Lane, Wyndmoor, PA 19038, USA. Electronic address: yiping.he@ars.usda.gov.
authors.forename: Yiping
authors.initials: Y
authors.lastname: He
authors.affiliation: Molecular Characterization of Foodborne Pathogens Research Unit, US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center (USDA-ARS-ERRC), 600 East Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Sue
authors.initials: S
authors.lastname: Reed
authors.affiliation: Molecular Food Microbiology Laboratory, Department of Food Science, Purdue University, 745 Agricultural Mall Drive, West Lafayette, IN 47907, USA.
authors.forename: Arun K
authors.initials: AK
authors.lastname: Bhunia
authors.affiliation: Molecular Characterization of Foodborne Pathogens Research Unit, US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center (USDA-ARS-ERRC), 600 East Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Gehring
authors.affiliation: Molecular Characterization of Foodborne Pathogens Research Unit, US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center (USDA-ARS-ERRC), 600 East Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Ly-Huong
authors.initials: LH
authors.lastname: Nguyen
authors.affiliation: Molecular Characterization of Foodborne Pathogens Research Unit, US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center (USDA-ARS-ERRC), 600 East Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Irwin
mesh_terms: D000362:Agar; D000818:Animals; D001431:Bacteriological Techniques; D015374:Biosensing Techniques; D017000:Campylobacter coli / Q000145:classification* / Q000302:isolation & purification*; D016123:Campylobacter jejuni / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D002645:Chickens / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis; D019453:Escherichia coli O157 / Q000302:isolation & purification; D005516:Food Microbiology; D057166:High-Throughput Screening Assays; D007834:Lasers; D008089:Listeria monocytogenes / Q000302:isolation & purification; D008460:Meat / Q000382:microbiology; D025341:Principal Component Analysis; D060888:Real-Time Polymerase Chain Reaction; D012475:Salmonella / Q000302:isolation & purification; D012542:Scattering, Radiation
chemical_list: D004269:DNA, Bacterial; D000362:Agar
keywords: Campylobacter; Detection; Light scatter image; Optical laser scattering technology; Passive filtration