Bacteriological Safety of Some Snacks Sold in Fast Food
Shop within Maiduguri Metropolitan Council.
A. M. Bukar, and Y. I. Abadam, B. A. Mohammed, Z. A. Turajo and F. B. Majama
Department of Science Laboratory Technology, Ramat Polytechnic Maiduguri, P.M.B. 1070 Maiduguri,
Borno State- Nigeria.
*Author for correspondence: E-mail: alhmodubuk@gmail.com
ABSTRACT
Ready to eat foods play a significant role in feeding the urban population with cheap, accessible and
nutritious foods. This study aimed at assessing the bacterial colonizers, of snacks (ready to eat food) sold in
within Maiduguri to determine its safety for consumption. Ready to eat food can lead to food poisoning and
consequent food borne illnesses. Standard microbiological methods were used for isolation, enumeration and
identification of bacteria. This study was carried out to investigate bacterial safety in the vending of street
foods in Maiduguri, namely: University Maiduguri, Mr. Biggs and a local kiosk were analyzed for total
heterophic bacteria count on nutrient agar plates. Local kiosk showed the highest bacteria count of meat-pie 4
× 103cfµ, buns 6 × 103cfµ and doughnut 11 × 103cfµ, followed by UNIMAID; meat-pie 1 × 103cfµ, buns 5 ×
103cfµ and doughnut 9 × 103cfµ, then Mr. Biggs with the lowest bacteria load; meat pie 1 × 10 3cfµ, buns 1 ×
103cfµ and doughnut 3 × 103cfµ. Four (5) different bacterial isolates were identified which are Staphylococcus
epidermidis, Bacillus subtilis, Staphylococcus aureus and Corynebacteria speices. The frequency of bacteria
isolated and the percentage of occurrence of bacterial isolated were analyzed in relation to all the retail outlet,
were the highest are Staphylococcus aureus 50%, Bacillus subtilis and Corynebacteria speices 21.43%,
Staphylococcus epidermidis 7.14% which may be due to the poor sanitary practices by food personnel and
could be an indication of possible feacal contamination. The most predominant bacterial contaminants was
Staphylococcus aureus with 50%, this could be traced to the fact that it is abundant in human body (skin, nails,
hair), staphylococcus epidermidis with 7.14%, is normally found on the skin which can cause urinary tract
infections, 21.43% Bacillus species and were isolated; however, pseudomonas species were not detected.
Adoption of good manufacturing practice and hazard analysis critical control point (HACCP) are necessary to
preventing occurrence of food borne illness.
Key words: Food safety, Pathogens, Snacks, Ready to eat foods, food borne illnesses
INTRODUCTION
Snacks are foods that are consumed in the same state as that in which it is sold and
does not include nuts in shell and whole, raw fruits and vegetables that are intended for
hulling, peeling or washing by consumer (Gilbert el al,2000). There is a wide variety of
snacks foods, including sandwiches, meat-pie, doughnuts, buns, samusa, kebabs, salad,
takeaway foods and bakery products. Convenience/modern life style, industrialization,
economic down turn quest for more wealth, materialism, and their associated power are
reason for the increased patronage for snacks (Nielson, 2006).
Food borne illness is disease, usually either infections or toxic in nature, caused by
agents that enter the body through the ingestion of food (WHO, 2007). Microbial agents that
cause food borne illness may include, bacteria such as Salmonella, Staphylococcus aureus,
Escherichia coli, (pathogenic strains) Bacillus species, Clostridium botulinum, Listeria
monocytogens; Viruses such as; hepatitis A and E, Norovirus; molds, fungi, and yeast (CDC,
2010). In addition, poisonous chemicals, or other harmful substance can cause food borne
diseases if they are present in food. Some can cause organ failure. WHO (2007) estimated that
a significant proportion of the approximately 1.5 billion episodes of diarrhea and more than 3
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million deaths globally recorded annually, results from consumption of food with microbial
pathogens and toxins. We live in a microbial world, and there are many opportunities for food
to become contaminated as it is produced and prepared, many of these food borne microbes
are found in healthy animals raised for food (usually in their intestine). Meat and poultry
carcasses can become contaminated and during slaughter by contact with small amounts of
intestinal content. Similarly, fresh fruits and vegetables can be contaminated if they are
washed or irrigated with water that is contaminated with animal manure or human sewage
(Adesiyun, 1995).
Although governments throughout the world are attempting to improve the safety of
the food/snacks supply, the occurrence of borne disease remains a significant health issue in
both developed and developing countries (WHO, 2011). The global incidence of food borne
disease is difficult to estimate, but it has been report that in 2005 alone 1.8 million people
died from diarrheal disease. A great proportion of these cases can be attributed to
contamination of food and drinking water (WHO, 2011). Pathogens and the relationship
between their occurrence and the hygiene practices in Maiduguri. This could of the reveal
potential of food poisoning outbreak relating to snacks consumption and relate this to
handling practices through evaluation pathogen city of the microorganisms isolated from
snacks matrices.
MATERIALS AND METHODS
Study area
The practical was conducted at the Department of Veterinary medicine, University of
Maiduguri. Maiduguri is located on latitude 1150 N and longitude 1350E it has an area of 50,
778 square kilometers. It’s the largest town in north eastern Nigeria. It shares its borders
internationally with the republics of Niger to the north, Chad to the north east and Cameroon
to the East. Within the country, its neighbours are Adamawa to the south, yobe to the west
and Gombe to the south – west. It has an annual rainfall of 650mm and it is inhabited by
about 908,645 people.
Source of sample
Three (3) ready-to-eat food vending sites were choose randomly because they are
highly patronized by members of the general public of different socio-economical classes
(upper, middle and lower class) they are Mr. Biggs (upper class) a snack shops in University
of Maiduguri (middle class) and local kiosk (lower class).
Sample collection
A total of nine (9) samples of Buns, doughnut and meat-pie were aseptically
purchased in a sterilize polyethylene bags. The location of the samples include; University of
Maiduguri, Mr. Biggs and local kiosk and transported to university of Maiduguri laboratory
for further analysis.
Sample preparations
The samples (buns, doughnut and meat-pie) were aseptically blended. Serial dilution
were made up to ten fold dilutions for each prepared samples by weighing 1g of the snacks
sample and dissolve in 9ml of sterile distilled water for the serial dilution experiment. These
were carried out in order to obtain discrete colonies.
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Plating and culturing
0.1ml was taken from 1-10 dilution and the streaking plate method was used on blood
agar and Mac Conkey agar over one corner which has sufficiently dried, the wire loop was
sterilized over a Bunsen flame, cooled and used to make parallel streak from the main
inoculating plate, the plates were then inoculated at 310C for 24hrs before being read.
Identification of micro organism
The isolated were identified by conventional methods as described by (Ogontona and
Tella, 1999). Briefly, using a sterile wire loop a drop of normal saline was put on the centre
of grease. Free slide and a portion of colony was picked and emulsified into the drop of
sample and allowed to air dry before fixing. To gram stain, crystal violet was then applied by
3min. It was then replace with a gram’s iodine for one minutes, prior to rinsing with water
and application of 95% alcohol until no colour appeared on the flow. Slides were then rinsed
with water and safranin applied for 1-2min. this was followed by rinsing and air-drying
before being observed microscopically under xi-00 emersion oil objective. Growth was
interpreted as described by (Chakravarty, 1996). Where interpreted that coccin chain
indicated the present of Gram-positive bacteria and cocci in cluster identify the present of
gram-negative bacteria.
Sub-culturing
After the gram-staining the bacteria were sub-culture onto the chocolate agar which
support the growth of fastidious bacteria such as gram negative bacteria and the gram positive
were sub-culture onto manitol salt agar which is selective media for the growth of
staplyococcus species
Biochemical test
Catalase test
This test was carried out with a drop of 3% hydrogen perioxide put on a clean greasefree slide and a colony of the test organism was picked and emulsified (mixed) in the drop of
the hydrogen perioxide and was examined for a gas bubble which indicate catalase positive
and the absence of gas bubbles indicate catalase negative. The test was used to differentiante
between staphylococcus species and streplococcus species. The gas bubbles observed in the
reaction was due to the breakdown of hydrogen perioxides to oxygen and water by an
enzymes called catalse.
Coagulase test
coagulase test was carried out on all species of staphylococcus using a drop of normal
saline or physiological saline on a clean glass slide. A drop of rabbit plasma was added and
mixed coagulase positive shows dumping or aggutanation immediately this test is used to
differentiate pathogenic staphylococcus aureus from non-pathogenic ones; staplylococi.
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RESULT PRESENTATION
Table 1 show the total heterophic bacteria count on nutrient agar plates that were
recorded. Local kiosk showed the highest bacteria count of meat-pie 4 × 103cfµ, buns 6 ×
103cfµ and doughnut 11 × 103cfµ, followed by unimaid; meat-pie 1 × 103cfµ, buns 5 ×
103cfµ and doughnut 9 × 103cfµ, then Mr. Biggs with the lowest bacteria load; meat pie 1 ×
103cfµ, buns 1 × 103cfµ and doughnut 3 × 103cfµ.
Table 2 show the bacterial isolated from the snacks samples, which are
staphylococcus epidermidis, Bacillus subtilis, staphylococcus aureus and corynebacteria
speices.
Table 3 show the morphological appearance; gram reaction and biochemical
characterization of bacteria isolated from the snacks sample, that were observed and recorded
on blood and macconkey agar respectively.
Table 4 show the frequency of bacteria isolated from the (9) snacks sample and the
percentage of occurrence of bacterial isolated in relation to all the retail outlet, were the
highest are staphylococcus aureus 50%, bacillus subtilis and corynebacteria speices 21.43%
with 30% which may be due to the poor sanitary practices by food personnel and could be an
indication of possible feacal contamination.
Table 1: Mean Count of the Bacterial Load obtained from different Snacks sources
analyzed in the study.
Snacks
Locations
Mr. Biggs
UNIMAID
Local kiosk
Meat-pie
1 × 103cfµ
1 × 103cfµ
4 × 103cfµ
Buns
1 × 103cfµ
5 × 103cfµ
6 × 103cfµ
Doughnut
3 × 103cfµ
9 × 103cfµ
11 × 103cfµ
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Table 2: Identification of bacteria isolation based on colonial morphology, gram
reaction and biochemical test from snacks samples
Colonial morphology
Coagulase
test
Catalase
test
Gram
reaction
species
Cocci arranged ingrape-like
cluster, colony on blood
agar
–
+
+
Staphylococcus
edipermidos
Large rod colony on
marconkey agar
–
+
+
Bacillus subtilis
Small rod colony on blood
agar
–
+
+
Corynebacteria
Circular yellow colony on
blood agar
+
+
+
Staphylococcus
aureus
Table 3: Bacteria isolated from nine (9) snack samples analyzed
Snacks
Location
Mr. Biggs
Unimaid
Local kiosk
Meat-pie
No growth
No growth
Corynebacteria species
Buns
No growth
Staphylococcus
Bacillus subtilis
Bacillus subilis
Staphylococcus aureusn
Corynebacteria species
Corynebacteria species
Doughnut Bacillus subtilis
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Table 4: Percentage, frequency of bacteria isolated from nine snacks samples analyzed
Bacteria isolate
Frequency
Percentage (%)
Bacillus substills
3
21.43
Staphylococcus aureus
7
50
Staphylococcus epidermidis
1
7.14
Corynebscteria species
3
21.43
Total
14
100
Discussion
The most predominant bacterial contaminants was staphylococcus aureus with 50%,
this could be traced to the fact that it is abundant in human body (skin, nails, hair) (Balaban et
al., 2000) staphylococcus aureus is normally found on the skin which can cause urinary tract
infection with, with 10% Bacillus species were isolated; however, pseudomonas species were
not detected. Pseudomonas species is known to be environmental contaminants and
opportunistic pathogens (Eni et al., 2010), have been implicated in food borne disease, and
are known to cause food spoilage that can lead to economic loss. A comparison of the level of
contamination of snacks from sampling points representing 3 socio-economic classes: upper,
middle and lower class shows differences in their level of contamination although the Mr.
Biggs have lowest contamination compared to the unimaid and local kiosk with reatively
higher level of contaminations (Nielson, 2006).
Snacks (ready to eat foods) are eaten by all age groups with high popularity amongst
school children and youths, it is therefore mandatory that these foods must be free from
contamination as much as possible. Food borne illness can be prevented by good hygiene
practice during the preparation of food. To prevent occurrence of food borne illness it is
therefore, important to ensure that food sold are safe and hygienic, public awareness
programs should be employed to educate personnel involved in food preparation, food
processors, and food vendors. The general public should be educated on the need for food
safety and requirement for water meant for human consumption and for food processing
(Taulo et al., 2008). Proper and regular hand washing, sanitization of all equipment and
utensils, care for the environment and the packaging materials so as to prevent the spread of
contaminants will help in safety of food. Adoption of the HACCP (Hazard analysis Critical
Control Point) principle in snacks preparation is advocated
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5.2
CONCLUSIONS
In conclusion, studies have indicated that snacks and foods preparation surfaces may
be reservoirs for microbial contamination (Mankee et al., 2005) food borne microorganisms
cause disease through infection or intoxication. There was need to study the strain
distribution and pathogenicity of presumptive food pathogens and the relationship between
their occurrence and relate to the hygienic practices in Nigeria. This could reveal potential of
food poisoning outbreaks relating to snacks consumption
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