Comparison of enumeration methods for salmonella spp. contaminated in agricultural samples

• Main Authors: Somphee P., Shutsrirung A., Choonluchanon S.
• Format: Article
• Published: Chiang Mai University 2015
• Subjects: Multidisciplinary
• Online Access: http://www.scopus.com/inward/record.url?partnerID=HzOxMe3b&scp=84872237119&origin=inward; http://cmuir.cmu.ac.th/handle/6653943832/38044
• Institution: Chiang Mai University

Salmonella spp. infections associated with vegetables crops have occurred with increasing frequency in recent years. Conventional methods (plate count) for detection of Salmonella spp. is time and labor consuming. Nowadays, the advanced molecular techniques especially realtime PCR (RT-PCR) is popular for estimating the quality and quantity of bacterial population. The aim of this study was to develop a method for detection of Salmonella spp. as guideline for rapid and accurate determination. The comparison of enumeration methods included BAM (Bacteriological Analytical Manual), plate count technique, and RT-PCR using pure cultures of S. typhimurium ATCC 13311 derived from the Department of Medical Science, Ministry of Public Health of Thailand. RT-PCR was the most accurate method to quantify the contamination of S. typhimurium ATCC 13311 (9.40 log CFU/mL) which was significantly comparable to that of plate count technique (8.94 log CFU/mL). These methods were also done in determination of agricultural samples. RT-PCR could detect contamination in all 100 samples whereas BAM method could detect only 25 samples. Moreover the RT-PCR has the advantage of fast (4:30 h), precise and occupied small space to work.