The Occurrence of Bacillus Cereus in White Pepper from Bogor, Indonesia

Abstract

Abstract White pepper (Piper nigrum L.) is a spice with earthy heat and an intense floral aroma widely produced and consumed in Asia. In Indonesia, it is commonly used to flavor dishes that require a spicy taste. However, white pepper can be contaminated by pathogenic microorganisms, such as Bacillus cereus, an endospore-forming bacterium widely grounded in soil and dust. The bacterium causes emetic and diarrheal syndromes and has been implicated in various foodborne disease outbreaks in different parts of the world. Currently, data pertaining to the occurrence of Bacillus cereus in white pepper in Indonesia is not available. This study aimed to isolate and assess the occurrence of Bacillus cereus in white pepper obtained from markets in Bogor, Indonesia. The study consisted of sample collection and preparation, isolation and enumeration of Bacillus cereus using Mannitol egg yolk polymyxin (MYP) agar, and confirmation by biochemical tests and Polymerase Chain Reaction to detect the gene encoding for16S rRNA. Of the 20 samples analyzed, 18 of them (90%) were contaminated with presumptive Bacillus cereus, and the highest concentration was 5.77 log10 cfu/g. The high counts of Bacillus cereus were probably attributed to the postharvest processing operations that the spice encountered. All the 15 tested isolates showed a clear band at the expected length of around 1686bp after being separated from PCR products on ethidium bromide-stained 2% agarose gel. This result confirmed the existence of Bacillus cereus in white pepper samples.