Microfluidic rapid quantification of Salmonella enterica serovar Typhimurium collected from chicken meat using immunomagnetic separation after formaldehyde treatment

Abstract

Foodborne pathogens such as Salmonella enterica serovar Typhimurium, which cause self-limiting gastroenteritis, are important in food safety and public health. Detection of Salmonella in complex food matrices is required for rapid and effective monitoring of contaminated food products. In this study, we collected Salmonella Typhimurium in chicken using immunomagnetic separation after formaldehyde treatment. Collected Salmonella Typhimurium cells were then quantified microfluidic device or fluorescence microscopy. The recovery ratio obtained with immunomagnetic separation after formaldehyde treatment was 77 (±5)% for the microscope count and 63 (±9)% for the microfluidic count. According to the fluorescence microscope images, the food matrix was effectively removed from the collected cell suspension. The counts of Salmonella Typhimurium cells obtained by the microfluidic device and fluorescence microscope were closely correlated (R2 = 0.993) with a range of 3.3 (±0.5) × 103 to 1.2 (±0.5) × 106 cells g−1. Our method provides quantitative detection of Salmonella Typhimurium within 3–4 h and could be used to efficiently evaluate microbial risk of quality control of foodstuffs and prevention of foodborne disease.