ABSTRACT

Recently, there were several cases of bacterial food poison in the student community of Ambrose Alli University, Ekpoma. However, there were no studies that Isolated the common bacteria causes of food poison in this environment. The objective of this study was to find causes food poisoning, isolate and characterize the common bacteria food poison in Ekpoma, Nigeria. METHOD: Ten prepared vegetable salad samples obtained at various sales points in Ekpoma were investigated for the isolation of Bacteria using standard cold and noncold enrichment method. RESULT: The result obtained demonstrated the presence of Staphylococcus aureus 50, Bacillus 30, Proteus 20, Yeast 10. The commonly diagnosed Listeria monocytogene was not isolated. CONCLUSION: Appropriate hygienic measures for the consumption of raw food products, canned foods and vegetables should be practiced.

CHAPTER ONE

1.0INTRODUCTION

Certain bacterial agents have been implicated in outbreaks of food poisoning on the basis of presumptive and inconclusive evidence.1 Year after year some of these same agents are reported in the literature without additional proof as to their etiological significance. As a result many misconceptions have arisen in textbooks and scientific journals regarding the role of such agents in food poisoning. It is the purpose of this paper to point out some of the problems in this field and to illustrate with a few examples some of the difficulties in assigning significance to these organisms. Many kinds of microorganisms have been alleged to cause food poisoning merely because they have been found in large numbers in implicated foods, or in the vomitus or stools of patients. Some of these bacteria are natural inhabitants of the intestinal tract of healthy persons and there is no reason other than the circumstantial evidence cited for assigning them causative rBles in food poisoning. Most food at the time of eating contains many kinds of viable bacteria and certain foods may contain millions of bacteria per gram without causing illness. In the latter circumstances it should not be surprising to find the kind of organisms which are isolated from heavily contaminated food also appearing in specimens of vomitus and feces.

When illness follows the eating of a specific item of food there may have been a lapse of many hours before a sample is collected for laboratory study. Often the food specimen is recovered from a garbage pail where it has been subject to contamination from other decaying foods and has been held at a temperature for a sufficient time to change the bacterial population from that present at the time of eating. Another error is the failure to exclude known food poisoning bacteria or their products as the cause of illness. For example, staphylococcus enterotoxin gives rise to well defined symptoms with illness appearing 1 to 5 hours usually 2 1/2 to 3 hours after swallowing the enterotoxin. There is frequently marked prostration, and in some cases shock. Vomiting and diarrhea are prominent symptoms and blood and mucus may be present in the discharges. The illness tends to be more severe when the incubation period is short. When a large number of persons presenting these symptoms is observed, it is important to rule out staphylococcus food poisoning before implicating another organism. Staphylococcus enterotoxin withstands boiling temperatures and for this reason it is possible to have enterotoxin present in a food after the organisms have been killed.

Many bacteria other than staphylococci have been assigned as causative agents in food poisoning outbreaks that were undoubtedly caused by staphylococcus enterotoxin. Although it is possible that other agents may simu late staphylococcus food poisoning, there has never been a clearly proven example of such an exception. Aside from botulism and staphylococcus food poisoning which are caused by toxins preformed in food, other outbreaks of food poisoning follow the ingestion of living organisms. The symptoms and incubation period of the latter group, which include the salmonella and certain alphatype streptococci, may not readily be distinguished or the condition diagnosed except by finding the specific agents and excluding other types of food poisoning. Too often only media selective for the Gramnegative intestinal bacteria have been used for the examination of specimens without concurrent use of media that support growth of the alphatype streptococcus.

Recently several species of microorganisms such as paracolon bacilli, Salmonella pullodum,6 Proteus mirabilis, 7 Clostridium perfringens,8 and hemolytic streptococci9 have been implicated as possible causative agents of food poisoning. All of these microorganisms when grown in suitable media produce substances which are toxic for animals by the parenteral route. This property of culture filtrates of various microorganisms to produce diarrhea and vomiting in animals by the parenteral route has frequently given rise to difficulty in the identification of enterotoxic material. In distinction to the above, a true enterotoxin is toxic when fed in adequate amounts to suitable animals. They may also be toxic by the parenteral route.

Since many of the above microorganisms have been implicated from time to time over a period of years, it is imperative that their role in the etiology of food poisoning be established. A positive solution to the problem would involve the feeding of cultures and filtrates to human volunteers. Obviously this procedure is not to be recommended, since in, the case of many members of the group of Gramnegative intestinal bacteria, their pathogenicity is unknown. Furthermore, in food poisoning outbreaks caused by certain well established salmonella species e.g., S. enteritidis, S. cholera suis, an occasional person may develop a systemic infection. Although there is little evidence that other species of salmonella isolated in association with food poisoning produce systemic infection, the possibility of such infections is sufficient reason for condemning such an approach to the problem.

In the absence of a direct approach involving the feeding of living agents to human volunteers, proof of the etiologic significance of an agent in food poisoning outbreaks rests upon a number of observations and tests. A careful epidemiological study is valuable, especially in outbreaks in which a single item of food may be established as a common denominator for all who were made ill. This becomes difficult in the presence of a prolonged incubation period. If an implicated item of food can be secured, it is important to know what has happened to it and whether or not it has been kept under refrigeration or has been heated since the time of the outbreak. If, by good fortune, the food has been refrigerated, then a quantitative study of the bacteriological flora should be made, including a search for all probable food poisoning agents. A search should be made for agents in the stools and vomitus of patients, and blood cultures may be desirable in infections resembling those caused by salmonella.

In the case of food poisoning agents such as salmonella, which are associated with infection rather than intoxication, there may be some valuable information collected with reference to the development of agglutinins or other immune bodies in patients recovering from attacks of the disease. The interpretation of low agglutinin titers is unsatisfactory. In all cases where the agglutination test is employed the limitations of the test should be borne in mind, and the possibility of previous exposures or immunizations should be considered. It is well known that in mild attacks of gastrointestinal illness caused by salmonella, slight or no rise in agglutinin titers may be found in the sera of patients during convalescence.

1.1BACKGROUND OF STUDY

Food borne diseases are multi factorial in origin. It could follow ingestion of Food containing infectious organisms or non infectious substances. Foodborne diseases FBDs constitute a serious public health problem worldwide. 1 There is an estimated 2 million deaths in children worldwide. 2 Chemicals, heavy metals, parasites, fungi, viruses and bacteria can cause food borne illness. However, bacteria related food poisoning is the most common, but less than 20 of the many thousands of different bacteria actually are the culprits. More than 90 percent of the cases of food poisoning each year are caused by Staphylococcus aureus, Salmonella, Clostridium perfringens, Campylobacter, Listeria monocytogenes, Vibrio parahaemolyticus, Bacillus cereus, and Enteropathogenic Escherichia coli, proteus. Yeast have also been reported as contaminants from reuse of rubber bags. 3 These bacteria are commonly found on raw foods like salads, eggs, beef, vegetables, cheese, ice cream, unpasteurized milk, fish, fresh fruits, canned foods, mushrooms etc. 4 Incubation periods of the various organisms causing food poison differs. Normally a large number of foodpoisoning bacteria must be present to cause illness.

There is neither racial, age nor sex predilection noted. However, some researchers have reported outbreaks of food poison involving specific group of bacteria in some areas. This depends on the source of food and method of food preparation which of course might be culture determined. Outbreaks of Staphylococcus aureus, Bacillus and proteus food poisons after eating in a restaurant have been reported by some researchers. In 2001, Norinaga Miwa reported an outbreak of staphylococcus aureus food poison due to the consumption of eggs in boxed launches prepared at their company cafeteria

Bacterial are group of microorganism all of which lack a distinct nuclear membrane and hence are considered more primitive than animal and plant cells and most of which have a cell wall of unique composition. Most bacterial are unicellular; the cells may be spherical coccu rod shaped bacillus, spiral spirillum, comma shaped vibrio or corkscrewshaped spierocheate. Generally, they range in size between 0.5 and 5um. Elizabeth and Martin, 2003.

Food is any substance that people or animal eat or drink or that plants absorb to maintain life and growth. Food is any substance consumed for nutritional support for the body; it is usually of plant or animal origin. Ezeronye, 2007. Food consists of chemical compounds which heterophilic living thing consumes in order to carry out metabolic processed. They are also substances which when introduced to the digestive system under normal circumstances contribute to growth, repair and production of energy.

Infectious agents comprise the largest category of food poisoning, but as seen from the above top categories, viral infections comprise the bulk of infected patients but are far less likely to cause hospitalizations and deaths than Salmonella bacteria. Because the bulk of unspecified causes is probably similar to the makeup of the diagnosed causes, this grouping of viruses and bacteria is considered to be the main causes of food poisoning in Nigeria.

Certain chemicals are considered toxins that can cause food poisoning. Although there are over 80,000 chemicals used in the country, only a few have been well studied. While most do not enter into foods, some do and cause food poisoning. An example of such a chemical is mercury, found in drinking water and in fish such as tuna and marlin. Other examples of chemicals that can be toxic if enough contaminates food and water are pesticides, polychlorinated biphenyls, and lead.

1.2 STATEMENT OF PROBLEM

Food poison has happen to be a major problem to the society, mostly to the eateries and fast food joints, any open place where eatable food are prepare and sold too people. The research have discovered that most of this food after a test on its sample happens to have virus types of food poisoning agents in them. Comparing it with most of the food prepared at individual homes. Due to this it cut the attention of the researcher to carry out this study, for more details causes of this food poisoning.

1.3OBJECTIVE OF THE STUDY

The undisputed reason for this research which the whole work is center upon is to further the analysis and causes of food poisoning among the hospitality industry using the caterer as the study point.

Other objectives of this research work are.

1.Highlight the importance of food hygiene to human health.

2.Aviate the possible means and methods for preventing food poisoning and its outbreak in our society.

3.Create awareness on the effect of food poisoning to the body system and for good living.

1.4 SIGNIFICANCE OF THE STUDY

This research work is significantly important to the society, the entire humans. This research will expose if not all, every source of food poisoning and the means of preventing them, this research work will also, create the awareness of the impending danger of food poisoning to the human body mechanism / system.

1.5 DEFINITION OF TERMS

Poisons: poisons are substances that cause disturbances in organisms, usually by chemical reaction or other activity on the molecular scale, when an organism absorbs a sufficient quantity

Food: Food is any substance that people or animal eat or drink or that plants absorb to maintain life and growth.

Food poisoning: Food poisoning is an illness caused by eating or drinking food or water contaminated with viruses, bacteria, toxins, parasites, or chemicals.