THE PREVALENCE AND ANTIBACTERIAL SUSCEPTIBILITY OF STAPHYLOCOCCUS AUREUS ISOLATED FROM CABBAGE SOLD UNDER MARKET CONDITION IN KEFFI AND NASARAWA TOWN
CHAPTER ONE
1.0 INTRODUCTION
Cabbage or headed cabbage (comprising several groups of cultivars of Brassica oleracea)
is a leafy green or purple biennial plant, grown as an annual vegetable
crop for its dense-leaved heads. Closely related to other cole crops,
such as broccoli, cauliflower, and brussels sprouts, it descends from B. oleracea var. oleracea,
a wild field cabbage. Cabbage is a leafy vegetable of Brassica family,
and is round or oval in shape. It consists of soft, light green or
whitish inner leaves covered with harder and dark green outer leaves. It
is widely used throughout the words, and can prepared in a number of
ways, but most commonly, it is included as either as cooked or raw part
of many salads.
Cabbage heads are generally picked
during the first year of the plant’s life cycle, but plants intended for
seed are allowed to grow a second year, and must be kept separated from
other Cole crops to prevent cross-pollination. Cabbage is prone to
several nutrient deficiencies, as well as to multiple pests, and
bacterial and fungal diseases (Brassica, 2012).
The Food and Agriculture Organization of
the United Nations (FAO) reports that world production of cabbage and
other brassicas for 2011 was almost 69 million metric tons (68 million
long tons; 75 million short tons). Almost half of these crops were grown
in China, where Chinese cabbage is the most popular Brassica
vegetable. Cabbages are prepared in many different ways for eating. They
can be pickled, fermented for dishes such as sauerkraut, steamed,
stewed, sautéed, braised, or eaten raw. Cabbage is a good source of
vitamin K, vitamin C and dietary fiber. Contaminated cabbage has been
linked to cases of food-borne illness in humans (Ingram et al, 2000).
Cabbage seedlings have a thin taproot
and cordate (heart-shaped) cotyledons. The first leaves produced are
ovate (egg-shaped) with a lobed petiole. Plants are 40–60 cm (16–24 in)
tall in their first year at the mature vegetative stage, and 1.5–2.0 m
(4.9–6.6 ft) tall when flowering in the second year. Heads average
between 1 and 8 pounds (0.5 and 4 kg), with fast-growing,
earlier-maturing varieties producing smaller heads. Most cabbages have
thick, alternating leaves, with margins that range from wavy or lobed to
highly dissected; some varieties have a waxy bloom on the leaves.
Plants have root systems that are fibrous and shallow. About 90 percent
of the root mass is in the upper 20–30 cm (8–12 in) of soil; some
lateral roots can penetrate up to 2 m (6.6 ft) deep (Chantrell et al., 2002).
Cabbage has been selectively bred for
head weight and morphological characteristics, frost hardiness, fast
growth and storage ability. The appearance of the cabbage head has been
given importance in selective breeding, with varieties being chosen for
shape, color, firmness and other physical characteristics. Breeding
objectives are now focused on increasing resistance to various insects
and diseases and improving the nutritional content of cabbage.
Scientific research into the genetic modification of B. oleracea
crops, including cabbage, has included European Union and United States
explorations of greater insect and herbicide resistance. Genetically
modified B. oleracea crops are not currently used in commercial agriculture (Janick et al., 2011)
Cabbage has been linked to outbreaks of some food-borne illnesses, including Listeria monocytogenes and Clostridium botulinum.
The latter toxin has been traced to pre-made, packaged coleslaw mixes,
while the spores were found on whole cabbages that were otherwise
acceptable in appearance. Shigella species are able to survive in shredded cabbage. Two outbreaks of E. coli and Staphylococcus aureus
in the United States have been linked to cabbage consumption.
Biological risk assessments have concluded that there is the potential
for further outbreaks linked to uncooked cabbage, due to contamination
at many stages of the growing, harvesting and packaging processes.
Contaminants from water, humans, animals and soil have the potential to
be transferred to cabbage, and from there to the end consumer.
Cabbage heads generally range from 0.5
to 4 kilograms (1 to 9 lb), and can be green, purple and white.
Smooth-leafed firm-headed green cabbages are the most common, with
smooth-leafed red and crinkle-leafed savoy cabbages of both colors seen
more rarely. It is a multi-layered vegetable. Under conditions of long
sunlit days such as are found at high northern latitudes in summer,
cabbages can grow much larger.
One of their most important celebrated
benefits to health is their powerful antioxidant quality. This means
that cabbage and other similar vegetables scavenge radicals from around
the body, which can be very detrimental to overall health and are major
contributors to things like cancer and hearth disease.
Cabbage also has a number of anticancer
compounds, like lupoeol, sinigrin, and sulforaphane, which are known to
stimulate enzyme activity and inhibit the growth of tumors, which can
lead to cancer. One study, performed primarily on Chinese women, showed a
significant reduction in breast cancer when cruciferous vegetable like
cabbage were regularly added to their diet.
Cabbage is known to accumulate a
build-up of cadmium-binding complexes in its leaves, and one of the main
component of that is glutamine. Glutamine is a strong anti-inflammatory
agent, so consuming cabbage can reduce the effects of many type of
inflammation, irritation, allergies, joint pain, fever, and various skin
disorders.
Food must be visibly clean and free from
noxious materials. It should be also nourishing and attractive as the
aim of food hygiene should be the product and service of food which is
both safe and suitable for consumption, the safety of cabbage with
respect to food born disease is of great concern around the world (Yilma
et al., 2007).
A vegetable is the tender plant part
which is not sweet and may be flavored or spiced with condiments before
consumption. These plant or plant parts may be eaten raw as salad or
added to some cooked foods like rice vegetables are known to be reach in
vitamins, iron, calcium, proteins, fats and minerals. Leafy green and
yellow vegetables are valued highly for their vitamin A and iron
contents, vegetables are helpful in neutralizing the acid substances
provided in the course of digestion of meat, cheese and other foods as
they are valued as roughage which promote digestion and helps to prevent
constipation (Oyenugu and Fetuga, 1985).
While growing, cabbage may be exposed to
many source of contamination like contaminated sewage used in watering
the gardens from where these vegetables are grown. Salmonella species
and other pathogens are derived from raw and treated sewage.
Contamination of cabbage can been
reduced depending on the use of good agricultural practices in
harvesting picking, transporting and processing particular washing. The
importance of washing vegetable properly especially those eaten raw is
to effectively remove from the vegetables, any pathogenic microorganism
which may cause infections upon ingestion. Chlorine containing solutions
or other antibacterial compounds has been employed to reduce the number
of contaminating microorganisms in such vegetable (Lund, 1983).
Some food born infections outbreaks have
been reported to be due to field contamination before these greens are
even harvested. This exercise is essentially to establish the
bacteriological load of some fresh leafy vegetables that are usually not
cooked before consumption.
Staphylococcus aureus is a gram
positive coccus that occurs in grape –like clusters. It is a
enbacterium that is found on the surface of the human skin and mucous
membranes (Prescott et al., 2005). They form part of the normal
microbial flora of the skin, upper respiratory tract and intestinal
tract (Cheesborough. 2005).
Staphylococcus aureus is a type
of bacterial species commonly found on the skin and hair as well as in
the noses and throats of people and animals. These bacterial are present
in up to 25% of healthy people and even more common among those with
skin, eye, nose and throat infection. Staphylococcus aureus can
cause food poisoning when a food handler contaminates food and then the
food is properly refrigerated. Other sources of food contamination
include the equipment and surface on which food is prepared. These
bacteria multiply quickly at room temperature to produce a toxin that
cause illness. Staphylococcus is killed by cooking and pasteurization.
Drug resistance by the organism is also a
major concern (Weinstain, 1998). Both methicillin (oxacillin or
cefoxitin) and glycopeptide (vancomycin and teicoplanin) resistance may
occur in Staphylococcus aureus. The emergence of antibiotic resistance microorganisms (e.g Staphylococcus aureus
) is increasing extremely rapidly around the globe, creating a serious
threat to the spread and treatment of infectious disease (Oli et al,
2013). Antibiotic resistance is a world wide. Health leaders have
described antibiotics resistant microorganisms as “nightmare bacteria”
that “pose a catastrophic threat” to people in every country in the
world (Bocksteal and Aerschot, 2009).
1.1 STATEMENT OF THE RESEARCH PROBLEM
The occurrence of bacterial pathogens in
cabbage is recognized as a sources of potential health hazard to man.
This is due to their production of bacteriotoxic compounds which are
capable of inducing several critical symptoms in man following
ingestion. The contamination of fruits and vegetable (cabbage) by
bacteria (Staphylococcus aureus) could also be as a result of
poor handling practice in food supply chain storage condition,
distribution, marketing practice and transportation.
1.2 JUSTIFICATION FOR THE STUDY
Cabbage is an important part of healthy
diet and provide a source of many nutrients including potassium, fiber,
folate (folic acid) and vitamins A,E and C. the nutrient in vegetables
are vital for health and maintance of once body. So also fresh
vegetables could carry abundant bacteria on their surface which are
pathogenic.
Cabbage are healthy for man but they are
also the largest source of food born contamination. About 2.2 million
people get sick annually from eating contaminated leafy vegetables that
represent about 23% of the 9.6 million cases of food born illness each
year. Symptoms in an infected individual include diarrhea, vomiting and
Nausea. Its presence in food id by not properly washing of the cabbage
before consumption.
1.3 AIM OF THE STUDY
The aim of this research work was to determine the prevalence and antibacterial susceptibility of Staphylococcus aureus isolated from cabbage sold under market condition in Keffi and Nasarawa town.
1.4 SPECIFIC OBJECTIVE
The specific objectives of this study are to:
- Isolate and identify Staphylococcus aureus from cabbage sold under market condition in both keffi and Nasarawa towns.
- To determine the antibiotic susceptibility profile of the Staphylococcus aureus isolate
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