Poo-Khem is a traditional salted crab widely consumed in Thailand. It is made from crab, salt and water
and fermented with the natural microflora [1]. The fermentation process of Poo-Khem was based on the
natural microflora. The microbial quality of this product were depended on the species and loads of
pathogenic bacteria as well as the number of lactic acid bacteria. In the previous study, they found that Poo-
Khem was contaminated with pathogenic bacteria such as Bacillus cereus, Escherichia coli, Salmonella
Typhimurium and Staphylococcus aureus while LAB were found in a small number [2]. The present of
pathogenic bacteria in Poo-Khem may cause direct negative effects on human health.