Abstract

Portable Culture Devices for Detection of Specific Microorganisms from Foods

Anushree Lokur, I/C Principal & Head, Dept. of Microbiology, Ramnarain Ruia Autonomous College

Foodborne diseases put a major burden on healthcare systems. According to WHO, 600 million are affected by foodborne diseases and 420,000 die every year. Thus, feasibility of food testing, especially in low-income and low-resource areas, is of paramount importance. The current work presents a Portable Culture Device (PCD), for on-site microbiological testing of food in resource-limited settings. These devices are made from masking tape, paper and PDMS. These devices can be produced and used by minimally trained personnel. The devices are portable, require less of media and reagents, and can be disposed of by incineration. The current work deals with detection of specific microorganisms from food samples. As proof of concept studies, detection of coliforms, Escherichia coli and Staphylococcus aureus from various types of food samples has been demonstrated. The tests are based on the detection of specific enzymes for microorganisms. Chromogenic substrates are used for this purpose and the time required to give a coloured reaction is used to determine the microbial load. First, the devices were tested with known positive control cultures. Spiked samples were then used to test the devices as proof of concept followed by actual samples for field trial. The devices were found to be robust in field trials. The limit of detection of coliforms and E. coli on PCDs was found to be 10 2 CFU/mL while for S. aureus it was 10 4 CFU/mL. Thus, PCDs are an ideal alternative for point-of-control food testing.