CHAPTER ONE
1.1 INTRODUCTION
Staphylococcus aureus is a gram-positive cocci, and it is a member of the normal flora of the body, frequently found in the nose, respiratory tract and on the skin. It is a common causes of skin infection including:
- Abscesses
- Respiratory infection
- Pneumonia and even food poisoning.
Staphylococcus aureus was first identified in 1880 in Aberden, Scotland by Surgeon Sir Alexander Ogston in pus from a surgical abscess in and knee joint. (Udo et a.t, 1993). Staphylococcus aureus also is abundant in food that acquired a lot of human handling. Staphylococcus aureus survive in food with high salt and sugar concentration therefore in can survive in fast food e.g. doughnut, hamburger, sandwich etc. (Fessler et at., 2011).
They survive in wide range of temperature so little or mild heat does not destroy the organism in fast food because are prepared with mild heat or no heat at all so Staphylococcus aureus can strive on them.
Staphylococcus aureus is a pathogen that can cause a range of diseases which are significant to public health, and are important food-borne pathogen.
They cause blood stream infection, skin, and soft tissue infections, Pneumonia, hospital-acquired postoperative wound infection etc.
With the reduced time available for food preparation and/or consumption, in recent years, there have been changes in individuals’ eating habits, motivated especially by urbanization processes and the professionalization of women, substantially favouring the consumption of processed products and food prepared away from home.
Thus, the search for ready-to-eat meals produced on a large scale and with an increased in number of fast-foods outlets and individuals eating in cafeteria.
Staphylococcus aureus is considered the third-most important cause of food-borne disease in the world and has two characteristics, toxin production and antimicrobial resistance. This pathogen is considered an excellent indicator of thermal processing inefficiency, inadequate hygienic conditions during food production/preparation, or inadequate cooling after food preparation and improper handling of food during packaging. Regarding antimicrobial resistance, Staphylococcus aureus is one of the most microorganisms implicated in cases of noso-comial infection worldwide.
1.2 METHICILIN-RESISTANT STAPHYLOCOCCUS AUREUS
Methicilin-resistant Staphylococcus aureus refers to a group of gram-positive bacteria that are genetically distinct from other strains of Staphylococcus aureus. (Uwauzike, et al., 2004).
MRSA is any strain of Staphylococcus aureus that has developed, through horizontal gene transfer and natural selection, multiple drug resistance to beta-lactam antibiotics. 8-lactam antibiotics are a broad spectrum group which includes some penicillin derivatives such as methicillin and oxacillin, and cephems such as the cephalosporins. (Agerso et al., 2012).
Staphylococcus aureus resistance to antibiotics is due to the production of a penicillinase, an enzyme that inactivates the beta Iactamico ring of the penicillin molecule, making the antibiotic ineffective against Staphylococcus aureus. Methicillin resistance presented by Staphylococcus aureus is mediated by the presence of the mec A gene, which encodes the 2a protein (PBP2a) found in the cell wall of the microorganism.
In particular, strains of MRSA harboring genes encoding the Panton-Valentine leukocidin (PVL) toxin are of concern from a public health perspective because they are usually capable of causing severe skin and soft tissue infections and occasionally necrotizing pneumonia, which is associated with high mortality.
1.3 FAST FOOD
Fast food is a mass produced food that is typically prepared and served quicker than traditional food. The food is typically less nutritionally valuable compared to other foods and dishes. (Kitai et al., 2005).
Staphylococcus aureus food poisoning is cause by enterotoxins produced by Staphylococcus aureus particularly entero-toxin A-E. (Brown et al., 2005).
Food handlers serves as a source of transfer of Staphylococcus aureus from their skin and nostrils to the food that they handle especially fast food. (Taiwo, et al., 2005).
1.4 STATEMENT OF PROBLEM
Staphylococcus aureus is pathogenic organism commonly implicated in fast food which causes food poisoning in human. Research has shown that this is as a result of contact with food handler because Staphylococcus aureus is a normal flora of the nose, skin and hands of healthy individuals.
1.5 AIM/OBJECTIVE
To investigate the prevalence of methicillin – resistant Staphylococcus aureus in fast food.
The specific objectives are:
- To isolate and identify Staphylococcus aureus from fast food.
- To subject the Staphylococcus aureus isolate to common used antibiotics for its treatment especially methicillin, the guinolones and aminoglycorides, vanco-mycin etc.
1.6 JUSTIFICATION
Staphylococcus aureus is known to cause food poisoning by which is of public health concern; it is by virtue or as a result of enterotoxin A-E. Treatment of Staphylo-coccus food poisoning has ever become difficult or a challenge because of the emergence of methicillin-resistant strain of the organism.
This study therefore aims at investigating the prevalence of methicillin-resistant Staphylococcus aureus in order to alert regulatory agencies to take required actions.
