Development of immunoaffinity based detection platforms for food pathogens

Çam, Dilek
Salmonella and E.coli, food pathogens, are among the very important pathogens threating the health. Rapid and easy detection of these pathogens is crucial. In this context, lateral flow assay (LFA) platform prepared by gold nanoparticles (GNPs) based on antibody for Salmonella and E.coli O157:H7 was developed in the first part of this study. In second part, single chain variable fragments (scFv) and SNAP-Tagged full IgG (fusion protein) of se155-4 antibody specific to Salmonella were genetically produced. Target capturing potential of the antibodies was examined by conventional and immunomagnetic ELISA. HF180 and 36nm GNPs were ideal membrane and dimension, respectively in the developed LFA. The best recognized species were S. enteritidis and S. infantis. E.coli were also specifically captured by developed strips. 5x105 S. typhimurium and 3x104 E.coli cells were determined as limit of detection by strips. scFv captured 2.8x104 and 2.8x105 target cells alone and in bacterial mixture, respectively. To our knowledge, recognition of whole cells by scFv and fusion protein of se155-4 were the first records in the literature. Produced antibodies showed strong affinity to S. typhimurium LPS, live and killed S. typhimurium. With the recombinant production of se155-4 known as specific to serogroup B cells, its high affinity to Salmonella serogroup D LPS was indicated as the first, in this work. LPS was the best antigen with high affinity. 1.4x101 S. typhimurium cells were the minimum pathogens detected by immunomagnetic ELISA.


Development of rapid dipstick assay for food pathogens, Salmonella, by optimized parameters
Çam, Dilek; Öktem, Hüseyin Avni (Springer Science and Business Media LLC, 2018-10-25)
Salmonella is among the very important pathogens threating the human and animal health. Rapid and easy detection of these pathogens is crucial. In this context, antibody (Ab) based lateral flow assays (LFAs) which are simple immunochromatographic point of care test kits were developed by gold nanoparticles (GNPs) as labelling agent for Salmonella detection. For that purpose some critical parameters such as reagent concentrations on the capture zones, conjugate concentrations and ideal membrane type needed f...
Molecular evaluation and antimicrobial susceptibility testing of escherichia coli isolates collected from various food products in Turkey/
Kyere, Emmanuel Owusu; Soyer, Yeşim; Avşaroğlu, Dilek; Department of Biotechnology (2014)
Even though Escherichia coli (E. coli) is part of the intestinal microflora of healthy human beings and warm blooded animals, some strains of E. coli can be important food borne pathogens that can cause a wide spectrum of diseases, ranging from self-limiting to life threatening intestinal and extra-intestinal illnesses. Pathogenic E. coli that affect the intestines of humans have been grouped into six main pathotypes: Shiga-toxin-producing E. coli (STEC); of which enterohaemorrhagic E. coli (EHEC) is a path...
Use of Fourier transform infrared spectroscopy for rapid comparative analysis of Bacillus and Micrococcus isolates
Garip, Sebnem; Gözen, Ayşe Gül; Severcan, FERİDE (Elsevier BV, 2009-04-15)
The identification of foodborne microorganisms and their endospores in food products are important for food safety. The present work compares Bacillus (Bacillas licheniformis, Bacillus circulans and Bacillus silbtilis) and Micrococcus (Micrococcus luteus) species with Fourier transform infrared (FTIR) spectroscopy. Our results show that there are several characteristic peaks belonging to both the Micrococcus and Bacillus Species Which Call be used for the identification of these foodborne bacteria and their...
Molecular evaluation and antimicrobial susceptibility testing of Escherichia coli isolates from food products in Turkey
Kyere, Emmanuel Owusu; Bulut, Ece; AVŞAROĞLU ERKAN, MÜRŞİDE DİLEK; Soyer, Yeşim (Springer Science and Business Media LLC, 2015-06-01)
Some strains of Escherichia coli can be important food borne pathogens. Characterization and antimicrobial resistance testing of 28 E. coli isolates from random food samples obtained in Van, Turkey were performed. Primers for 6 indicator genes (fliC, stx1, stx2, eae, hlyA, and rfbE) for shiga toxin-producing E. coli and 5 indicator genes for each pathogroup (bfpA, aggR, ipaH, daaD, st, and lt) were used. E. coli isolates were also typed using pulsed field gel electrophoresis with the XbaI restriction enzyme...
Rapid and standardized methods for detection of foodborne pathogens and mycotoxins on fresh produce
YENI, F.; Acar, Sibel; Polat, Özlem; Soyer, Yeşim; Alpas, Hami (Elsevier BV, 2014-06-01)
Due to the increase in consumption of fresh produce regarding to the health demand in the last decades, a considerable portion of foodborne outbreaks has been trackbacked to contaminated fresh produce, which have appeared as highly possible vehicles for foodborne outbreaks nowadays. Delays in detection of pathogens and mycotoxins on fresh produce hindered the trace-back investigations in finding the source and revealed the urgent need of rapid and reliable methods. In the frame of this review, we summarized...
Citation Formats
D. Çam, “Development of immunoaffinity based detection platforms for food pathogens,” Ph.D. - Doctoral Program, Middle East Technical University, 2016.