TABLE
OF CONTENT
Title page
Certification
Acknowledgement
Table of content
Abstract
CHAPTER
ONE
Introduction and Literature Review
Aims and Objective
CHAPTER
TWO
Sterilization of Equipment
Sample Collection
Laboratory Preparation of
Processing of Sample
Enumeration of Bacillus Cereus from
Food Sample using Most Probable Number (MPN)
Culturing of Bacillus Cereus
CHAPTER
THREE
Result analysis
CHAPTER
FOUR
Discussion
Recommendation
Conclusion
References
CHAPTER
ONE
INTRODUCTION AND LITERATURE REVIEW
B. Cereus
is a spore forming organism capable of developing at a whole range of
temperature, PH and water activity values. (Barker et al; 2005) thus bacterium,
frequency associated with food born disease can be found in the natural environment
and isolated from various foods, including meat and meat production (Ahmed et
al; 1983).
Some of the enterotoxins produced by B.
Cereus causes food born diarrhea, characterized as the “diarrheic syndrome”
this syndrome can be associated with the productin of five different protein,
haemolysine, enterotoxin and enteroxins, non haemolytic enteroxine cytotoxins,
the symptoms last for a period of 12 to 24 hours and consist of abnormal pain, watery
diarrhoea and nausea. It is believed that the enterotoxins are mostly produced in
the small intestine of the individual (Ankolekar et al; 2009) food associated with
outbreaks of B cereus diarrhoea fr4equency include protein rich foods and researcher’s
have emphasized the importance of the presence of microorganism or its spores in
meat and meat products for the occurrence of such outbreaks practices such as inadequate
temperature during food processing are indicated as the main factors
contributing to the spread of the microorganism in these foods, with the
objective of investigating the growth of enterotoxin producing B. Cereus in
processed meat, this study was carried out using cultures of the microorganism from
different origin (Bernhard et al; 1978) it is frequently isolated from milk and
dairy products (Ahmed et al 1983) in
milk B. Cereus causes a defect known as “bitty” cream or sweet curding. It is found
in rice, rice products oriental dishes and ingredients (Blaky et al; 1980) a
variety of foods have been implicated in food-poisoning (Johnson, 1984)
frequently isolated from soil and growing plants in the intestinal track of
insect and mammals (Arnesen et al; 2008)
Germination of most of the enterotoxigenic
strain of B. Cereus adhered to CaC0-2 cells is stimulated while another celline
HEP-2 does not trigger germination (Wijnands et al, 2007). The germination stimulated
by Cac0-2 cells is related to the normal functions of germination receptors (Horustra
et al, 2009) Beta-lactamase type I occur in the sporalated for run in
penicillin-resistant B Cereus (Fenselau et al, 2008)
B. Cereus is easily isolated and identified
from samples clinical specimens and food samples are collected, stored temporary
at refrigerating temperature and plated on selective agar media (Boschioits et
al, 1983) low level of peptone and the absence of carbohydrates in KG medium facilitated
formation of spore (Johnson, 1984). A columbia base 5% blood agar surface-spread
with polymyxin B is recommended by Kramer et al. (Kramer et l, 1982) for better
colonly characteristic and colony types are easily differentiated for serological
testing in enumeration by most probable number method, trypticase soy polymyxin
broth is recommended.
Bacaragar is a modified selective agar
and also contains Bacara and egg yolk. Pyruuate is found in rice, rice
products, oriental dishes and ingredients (Blakey et. Al. 1980; et al, 1986). A
variety of foods have been implicated in food-poisoning.
Emetic syndrome caused by bacillus
cereus is highly associated with rice and rice products (Johnson, 1984).
Reauire both Gerl and area germination
receptors for germination in inosine as the sole germinant, whereas the Gerl
receptor is responsible for most of the response to L-alarine as the sole
germinant, with a smaller contribution from identify with its homolog Gern
which is a Na+/H+-K+ antiporter that is
required for normal spore germination, while it has a significant role in
outgrowth; gert mutant spores do not outgrow efficiently under alkaline
conditions and outgrow more slowly than the wild type in the presence of high
Nacl concentrations. The Gert protein in B. Cereus therefore countibutes to the
success of spore outgrowth from the germinated state during alkaline or Na+
stress (senior et al, 2008).
Germination of most of the
enterotoxigenic strains of B. cereus adhered to caco-2 cells is stimulated
while another celline, Hep-2, does not trigger germination (wijnards et al;
2007). The germination stimulated receptors (Hornstra et al. 2009).
Beta-lactamase type I occurs in the
sporulated from the in penicillin resistant B. cereus (fenselau et alp; 2008)
B. cereus is easily isolated and identified from samples chemical; specimens
and food samples are collected, stored temporary at refrigerating temperature
if necessary, diluted if necessary, and plated on selective agar media.
Mami egg yolk polymyxin agar (MYP) is
usually recommended, polymyxin is the selective agent, and egg yolk and
mannitol are differential agents. Typical colonies are rough with.
B. Cereus is differentiated from other
non motile species by forming diffuse growth on predried nutrient agar as B.
Cereus Var. mycoides B.cereus is usually strong B-hemolytic on trypticase soy
sheep blood agar plate, whereas, B. thuringiensis and B. cereusvar. Mycoides
are often weakly hemolytic and B. anthracis is non motile and non hemolytic.
Endotoxcin crystals are found in B. thuringiensis (Harmon, 1978). Other
biochemical tests used in confirming B. cereus are: acid is produced from
anaerobic glucose fermentation, nitrate reduction, VP positive, tyrosine,
decomposition, selective growth on blood agar and bacara agar, Kramer etal,
1982) recommended the following biochemical test for confirmation of B. cereus:
Glucose +, mannotol, Xyclose-. And arabinose-, serotyping is recommended by a
number of investigators (Bernhard et al 1978).
B. anthracis and other Bacillus species
including B.cereus can also be identified by the rapid apitests with the aid of
computer programmes (Logan et al., 1985).
Among those strains of B. cereus
isolated from different foods and environmental samples, predominance of small
cluster of serotypes characteristics of the source is apparent, (Gilbert et
al., 1982)
Nonhaemolytic enterotoxin and cytotoxin
k are currently considered the aetiological agents of B. cereus related
diarrhoeal food borne disease. Hbi and Nhe are related three component toxins,
while the single component cytk belongs to the family of b-barrel pore-forming toxin.
In addition, several other protein cy totoxins, haemolysis and degraduative enzymes
have been described that may potentially contribute to the pathogenicity of B,
cereus diarrhoeal disease. These include cereolysin O, haemolysin TT haemolysin
III and three phosphotipases C (Stenfors et al, 2008)
CHARACTERISTIC
OF THE TWO TYPES OF BACILLUS COREUS FOODBORNE DISEASE
|
Characteristics
|
Diarrhoeal disease
|
Emetic disease
|
|
Types of Toxin
|
Protein: Enterrotoxin(S) Hbl, Nhe,
Cytk implicated
|
Cyclicpeptide: emetic toxin
(cereulides)
|
|
Location of Toxin
|
In the small intestine of the host.
|
performed in foods
|
|
Infective Dose
|
105-106CFU
(total) the total number required is lower for spores compared to vegetative
cells
|
105-106 cells
is often found in implicated foods but live cells are not required for intoxication
ceretice 8-10kg-7 weight caromal mode(s)
|
|
Incubahon Time
|
8-16h (occasionally 24h)
|
5-6h
|
|
Duration of Illness
|
12-24h (occasionally several days)
|
6-24h
|
|
Symptoms
|
Abdominal pain, watery diarrhoea
and occasionally nausea lethality has occurred
|
Nausea, Vomiting and Malaise. A few
lethal cases *(Possibly due to liver damage)
|
|
Food most Frequently Implicated
|
Protein aceous foods, meat products,
so ups, vegetables, puddings, Sauces, milk and milk product
|
Starch rich foods, fried and cooked
rice, pasta and noodles.
|
(Stenfors et al, 2008)
AIMS AND OBJECTIVES
The main objective of this project is
to;
Ø Determinacy
the highest frequently of bacillus cereus occurrence in selected food samples.
Ø Formulation
of a provincial food monitoring system.
Ø Proper
isolation and control
Ø Education
of food handler/sellers and analysis in food safely.
Ø Give
strategic directives for the development of food control and food safety.
Ø Outline
the nature of food monitoring which are needed in the medium
Ø Identify
the facilities, resources and staff required for rendering the monitoring
Ø Promotion
of the management system for food safety assurance.
Ø To
find an effective cure to the food-borne disease
Ø To
know its occurrence in food and management.
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