Their findings are published in the May edition of the Journal of Dairy Science.
Previous studies have reported that powdered infant formula (PIF) is a newly identified source of Salmonella infection in infants, which the authors of the study say means there is a high priority in the dairy industry to develop innovative means to detect Salmonella in PIF.
Current methods slow or expensive
Conventional culture-based methods for detection of Salmonella take two to three days.
In recent years, the authors point to other methods to rapidly detect nucleic acid targets of Salmonella, but these have disadvantages, including a relatively high cost, and the need for trained personnel.
However, the LAMP (loop-mediated isothermal amplification) method is based on a nucleic acid amplification approach that can generate up to 109 copies of the target DNA within one hour.
Therefore, the researchers state, LAMP is a fast, isothermal process (requiring only a heat block) and is robust, offering greater sensitivity than other comparable methods.
The specificity of the detection method approached 100% using 21 Salmonella and 31 non-Salmonella bacterial strains.
Potential for other dairy products
The authors of the study concluded that their methods provide a rapid, accurate and convenient detection system for detecting Salmonella in PIF, and likely several other dairy products.
They also noted that the method has great promise for food safety applications, or clinical diagnostics, especially for resource-poor laboratories.
The studies were undertaken at the Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin, and the National Research Center of Dairy Engineering and Technology, Northeast Agricultural University, Harbin.
Source: Journal of Dairy Science
Salmonella detection in powdered dairy products using a novel molecular tool
Yueming Zhao, Xia Jiang, Yanyan Qu, Ruili Pan, Xinyi Pang, Yujun Jiang, Chaoxin Man