Introduction
There are a number of factors that can influence the findings of bacteria cultivation and characterization from environmental samples.
For first off, the amount of bacterial cells can be one of the disadvantages that affects the accuracy of identification methods; the relatively small numbers of bacteria can lead to errors in the sampling and identification process. Second, culture-based approaches are time-consuming, costly, and always monospecific (that is, they identify only one species of pathogen). They also have a low throughput. Third, many pathogenic organisms found in the environment are either difficult to cultivate or non-cultivable (Roszak et al. , 1987). These pathogens could be the causal agents of different diseases (Rahman et al, 1996).
Bacillus cereus is a Gram-positive, spore-forming, facultative anaerobic, rod-shaped bacteria that produces unique toxins and is recognized to be one of the causative agents of food poisoning. Under 10 °C and above 50 °C, the bacteria’s vegetative cells can survive by generating spores, which can resist heat and drought and remain dormant for many years (Henriques and Moran, 2007), Cooking, even at 100 °C, and freezing would not be enough to kill this bacterium since it will revert to a vegetative state and proliferate once suitable conditions are restored. Identifying aerobic spore-forming bacteria found in industrial dairy processing environments and product spoilage (Genia Lückinget al ., 2013)
Bacillus cereus has a natural habitat in soil, but it can also be discovered in foods that have been improperly preserved, such as dairy products, rice, cereals and cereal derivatives, dried foods, spices, eggs, vegetables (salads), and meats (Granum, 2005). Bacillus cereus was only characterized as a food poisoning causative agent in 1955, and it is responsible for about 2% of all food-borne illnesses in the industrialized world. Food poisoning caused by B. cereus causes emetic (vomiting) and diarrhea symptoms. This is due to the bacterium and its spores producing emetic toxin and enterotoxins (Drobniewski, 1993) during food processing (Sagripanti et al ., 2006; Henriques and Moran, 2007).
Enterotoxins produced by B. cereus include hemolysin BL (HBL), non-hemolytic enterotoxin (NHE), and cytotoxin K. (Cyt K) (Beecheret al ., 1995; Granum et al ., 1999; Hardy et al ., 2001; Lindback et al ., 2004).
HBL, NHE, and HBL are three poisonous proteins that are composed of three parts. Necrotic enterotitis is caused by cytotoxin K, a pore-forming toxin (Lund et al ., 2000).
Several cereals poisoning outbreaks have been linked to B. cereus. (Kennedy, 2008). B. cereus has been connected to a number of cereal poisoning epidemics (Kennedy, 2008). The diagnosis of Bacillus cereus was based on the cultivation method, which has a relatively low specificity due to interference of the results The serological and gene expression tests, which are based on antigen and gene expression levels and have higher specificity and accuracy, were another method of Bacillus cereus diagnosis. Nucleic acid probes and PCR have recently been used to create highly sensitive detection methods for specific pathogens in environmental samples. Optimized immuno-capture PCR detection of pathogenic E. coli (Ogunjimi et al ., 1999), as well as sensitive real-time PCR detection of Salmonella and Campylobacter, have also been developed; however, these procedures are all monospecific and either tedious or very expensive for routine use in water testing laboratories. More recently, the multiplex polymerase chain reaction (m-PCR) has enabled speedy and very sensitive methods for detecting pathogenic microorganisms in environmental samples, such asBacillus cereus (Kalyan Kumar et al ., 2010).
Most pathogen detection m-PCR techniques have so far concentrated on only one, two, or three different types of organisms (Kong et al. , 1999).