Simultaneous enrichment and optical detection of low levels of stressedEscherichia coliO157:H7 in food matrices

Abstract

Aims: Rapid detection of enterohaemorrhagic E. coli O157:H7 in large range of stress conditions occurring in food processing. Methods and Results: Detection of E. coli O157:H7 in various food processing stress conditions using surface plasmon resonance imaging (SPRi) technique on an antibody microarray was evaluated. The direct detection method based on the culture/capture/measure (CCM) process consists of detecting bacteria during an enrichment step, which significantly decreases the overall assay duration. In optimized culture conditions, this method allows the specific detection of low CFU ml À1 in <7 h. Detection of bacteria directly in contaminated food samples was also conducted. Conclusions:The CCM technique using an antibody microarray is a label-free immunoassay that allows rapid detection of E. coli O157:H7 in both food processing stress conditions and complex food matrices. Significance and Impact of the Study: The assay is promising for detecting E. coli O157:H7 at different steps of food and drink processing and during storage. SPRi appears to be a suitable and powerful detection method for routine quality controls in food industry with important economic and societal impact.

Development of a lateral flow colloidal gold immunoassay strip for the simultaneous detection of Shigella boydii and Escherichia coli O157:H7 in bread, milk and jelly samples

“…So far, many methods have been developed to replace traditional techniques for food-borne pathogens' detection, for example, ELISA (Feng et al, 2013), chemiluminescence immunoassay (Y. Zhang et al, 2014), real-time PCR (Garrido-Maestu, Chapela, Vieites, & Cabado, 2014, multiplex PCR (Binet, Deer, & Uhlfelder, 2014), loop-mediated isothermal amplification (LAMP) (Kokkinos, Ziros, Bellou, & Vantarakis, 2014), evanescent wave fiber biosensor (Xiao, Rong, Long, & Liu, 2014), electrochemical immunosensors (Chan et al, 2013), surface plasmon resonance immunosensors (Mondani, Roupioz, Delannoy, Fach, & Livache, 2014;Wang, Ye, Si, & Ying, 2013), multiple cycle signal amplification strategy (H. Zhang et al, 2014) and PCR-strip joint detection technique (Chen et al, 2014). These methods have greatly improved sensitivity, specificity, and speed compared to the culture-based methods.…”

Immunological detection of Cronobacter and Salmonella in powdered infant formula by plasmonic label-free assay

“…In naturally contaminated food samples, we might thus observe different detection times due to stress of bacteria as shown by others in stressing conditions monitored on similar biochips formats (Mondani et al . 2 014).…”

Pathogen enrichment device (PED) enables one-step growth, enrichment and separation of pathogen from food matrices for detection using bioanalytical platforms

“…PED is a self-contained pathogen enrichment device designed to remove interfering particles and to recover a small volume (1-5 ml) of pH-adjusted homogeneous bacterial cell suspension for wide range of antibody or nucleic acid-based assay platforms such as PCR, ELISA, fiber-optic immunosensor, microfluidic biochip, biosensor, lateral flow strips, and fluorescence microscopy. This device also could provide enrichment of a sample using appropriate selective enrichment broth for a desirable time to suppress natural background bacteria and allow resuscitation and growth of stressed or injured cells to a level that could be detected by a bioanalytical detection system (Biao and Yuexia, 2013;Mondani et al, 2014;Zhou et al, 2011). This is particularly useful because most test organisms routinely encounter some level of stress during processing or storage of foods or food processing environments (Hahm and Bhunia, 2006;Lathrop et al, 2008).…”

“…This is particularly useful because most test organisms routinely encounter some level of stress during processing or storage of foods or food processing environments (Hahm and Bhunia, 2006;Lathrop et al, 2008). Without appropriate resuscitation, the chance for a false-negative result can be very high, which is unacceptable in many situations (Geng et al, 2006a;Mondani et al, 2014).…”