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).