Microbial Food Poisoning - Coursework Example

Microbial Food Poisoning Introduction Microorganisms are minute living things that are only visible under a microscope. Some organisms contaminate foods and cause diseases. Microbial contaminants account for most foodborne ailments. A comprehensive understanding of the growth, reproduction and spread of microorganisms is, therefore, critical to the prevention of foodborne illnesses brought about by these microorganisms. There are primarily four types of food contaminating microorganisms; bacteria, viruses, fungi and parasites. Under food contamination, these can further be divided into pathogens and spoilage microorganisms. Spoilage microorganisms ruin food quality without necessarily contributing to the spread of foodborne illnesses. For instance, mold ruins the taste and smell of foodstuffs but they may not necessarily cause illness. Pathogens, on the other hand, have been known to cause foodborne ailments without affecting the taste, smell or overall quality of food. Of the foodborne microorganisms known to man, bacteria provide the greatest concern in food preparation. This is because, under the right conditions, the reproduction and growth of bacteria can be expeditious. Bacteria may also survive under low temperatures and can easily adapt to new developing conditions, Educational Foundation of the National Restaurant Association (2006). Food Poisoning Food poisoning refers to illnesses caused by the consumption of contaminated food. Food poisoning is often caused by poor handling, storage and preparation methods. It can lead to severe illnesses and in some instances, even death. Food poisoning covers a wide range of illnesses and continues to be a growing challenge towards overall public health. Cases of food poisoning have been observed to occur due to poor practices during food production and consumption processes. Environmental contamination has also been attributed to the rising cases of food poisoning. Food poisoning usually manifests itself through gastrointestinal ailments. It has, however, been noted that gynaecological, neurological and immunological symptoms can, however, present themselves as a result of food poisoning. In more severe cases, food poisoning has been known to cause failures in multiple body organs and even cancer, World Health Organization (2014). Food poisoning contributes to approximately two billion illnesses globally in a year. It is estimated that about 700,000 deaths are reported yearly due to food poisoning in Asia alone. Approximately 2 million children worldwide die each year as a result of illnesses resulting from food and water contamination. Unfortunately, it has been noted that very few people visit their medical practitioners on food poisoning cases. UK’s Food Standards Agency (FSA) for instance reports that although roughly 5.5 million people in the country are affected by food contamination illnesses each year, only about 100,000 cases are tested and determined to be actual food poisoning, Teinaz (2006). In the USA, roughly 48 million people are victims of food poisoning though only about 128,000 are hospitalized and 3,000 succumb to death, Centres for Disease Control and Prevention (2014). In Australia, about 5.4 million cases of food poisoning result in gastroenteritis each year while about 120,000 cases of food poisoning related diarrhea are reported in Thailand each year. Foodborne bacterial diseases are common in Africa. Each year, about 800,000 children die from dehydration and diarrhea, Center for Science in the Public Interest (2005). Types of Food Poisoning Agents It is important to comprehensively know and understand the different agents of foodborne illnesses. Food microbiology dedicates itself to the study of the interplay between foods and the pathogens that exist in them. The discipline sets out to predict, prevent and control foodborne ailments through understanding the behavioral patterns of microorganisms in different conditions. Salmonella spp. Is a Gram-negative bacterial microorganism that causes a common foodborne illness known as salmonellosis. Salmonella spp. are a rod shaped bacteria belonging to the family Enterobacteriaceae. They have relatively minimal nutritional demands and survive in food over longer periods. Their existence depends on external factors such as pH, water activity and temperature. Once inside the gastrointestinal tract, they generate heat changes that lead to the loss of fluids in the intestines and in turn causes diarrhea. The heat changes may also result in damage to the mucosal surface of the intestines leading to inflammation. Salmonella spp. are transmitted via the fecal-oral route through contaminated food or from direct contact with other infected animals CFSANZ (2013). Escherichia coli, commonly referred to as E. coli, are a bacterium that is usually found in gut flora of warm-blooded animals including man. Most E. Coli are considered harmless. Others, such as the Shiga toxin-producing strain, have been known to cause serious illnesses in humans. An example is the haemolytic uraemic syndrome which can be deadly to humans. Their growth and survival also depend on external environmental factors. Infection by harmful E. coli may or may not have clinical signs. Clinical symptoms can manifest as abdominal cramps, diarrhea, fever and vomiting. Once ingested, the bacterium attaches itself to the walls of the gastrointestinal tract and cause lesions to appear. Often this leads to the appearance of blood in diarrhea. E. coli are also transmitted via the fecal-oral route through contaminated food or from direct contact with other infected animals CFSANZ (2013). Bacillus Cereus refers to a spore forming bacterium whose toxins cause vomiting and diarrhea in humans. They are rod-shaped bacterium belonging to the genus Bacillus and are usually found in nature and the soil. They produce two toxin types; emetic, that leads to vomiting, and diarrhea. They occur usually as either psychrotrophic or mesophilic strains. Whereas mesophilic strains thrive in temperatures ranging between 10-37º C, psychrotrophic strains do well in refrigeration temperatures and fair worse off at 37º, CFSANZ (2013). Botulism is a rare paralytic ailment caused by a toxin produced by Clostridium botulinum. The bacterium exists usually in soil and thrives well in low oxygen conditions. They can survive in an inert state over long periods of time by forming pores to support their development. There exists seven kinds of botulism toxins each designated by the alphabetic letters A to G though only A, B, E and, sometimes F, are disease causing. At the initial stages, botulism is characterized by blurry vision and droopy eyes though later symptoms manifest through speech impediment, difficulty in swallowing and even paralysis. Botulism can be diagnosed through other ailments like myasthenia gravis, the Guillain-Barré Syndrome and strokes, Department of Health, California (2005). The Hepatitis A virus (HAV) causes damage to the liver through inflammation and eventually jaundice. In many developing countries, Hepatitis A is an endemic whereas in more developed nations, few cases are observed. The virus belongs to the genus Hepatovirus which comprises of minute non-enveloped viruses and are better suited to environmental adaptability as compared to enveloped viruses. HAV requires a living host in order to replicate. Therefore, their rate of replication is considerably slowed during food handling process. It has been noted that, under typical environmental conditions, HAV remains infectious for up to about thirty days after being dried. Infection by HAV usually results in mild illnesses in humans or no clinical ailments at all. Where they occur, diseases are signaled by muscular and abdominal pain, vomiting, diarrhea, nausea and fever among others. HAV, however, targets the liver. Once they are ingested, they enter the liver through the vascular system where they use liver cells to replicate, often leading to inflammation of the liver CFSANZ (2013). Causes of Food Poisoning Bacteria pose the greatest concern when it comes to food safety. Disease causing bacteria are single-celled organisms that may be transmitted through food, water or other organisms such as man. Bacteria are menacing due to their quick growth and reproduction rates. In addition to this, they are able to form pores to enable them endure unfavorable conditions. As earlier mentioned bacteria can either spoil food or cause disease in humans through the toxins they produce or as they metabolize, reproduce and die. Bacteria usually thrive Examples of disease causing bacteria include salmonella spp. and bacillus cereus. Examples of foodborne illnesses caused by bacteria include fever, diarrhea, septicemia and meningitis among others, Educational Foundation of the National Restaurant Association (2006). Viruses are the tiniest of all the microbial contaminants. Viruses do not have a typical cellular structure and they do not replicate in food. They are different from other microorganisms in that they need other living hosts in order for them to replicate. As such, viruses, even prey on other microbial organisms such as fungi and bacteria. An Example of foodborne diseases attributed to viruses is Hepatitis A. Viruses can be transmitted through both food and water or between people and food contact surfaces. The most efficient prevention method for foodborne virus ailments is through the practice of proper personal hygiene, Centre for Disease Control and Prevention (2012). Parasites are organisms that depend entirely on other organisms, hosts, for their protection and nourishment. They are not necessarily microscopic and are usually transmitted between animals and humans through contact. They live in-between tissues and in the organs of infected hosts such as humans, rodents or pigs. Parasites may vary from single-celled organisms such as protozoa to multi-cellular organisms such as helminths. Examples of common parasites include Ascaris lumbricoides (roundworms), Taenia saginata (beef tapeworm) and Taenia solium (pork tapeworm). Examples of foodborne ailments caused by parasites include giardiasis, cryptosporidiosis and cyclosporiasis. All these ailments are characterized by diarrhea, abdominal cramps and mild fevers, United States Department of Agriculture Food Safety and Inspection Service (2011). Fungi are non-motile, single-celled organisms that vary in size from microscopic to larger multi-cellular organisms. They occur naturally in air, soil, animals and foods. Like bacteria, fungi can either ruin food or cause disease. They thrive in sweet, acidic foods that have little water activity. Examples of fungi include yeast, mold and mushrooms. Molds produce aflatoxins that lead to food spoilage. Molds can be eliminated through heating though some toxins need other methods of removal. Yeasts are also common food spoilers. They breakdown food and produce carbon dioxide and alcohol as products. As a result of this, the color and smell of food are significantly altered and this affects the quality of food. Fungi can be poisonous. Consumption of certain mushrooms for instance has been known to result in tracheal inflammation and blockage, nausea, hallucinations and even diarrhea. Pathogens A pathogen usually refers to a biological agent considered infectious and cause diseases as well as disease to its host, Koo (2009). Pathogens often interfere with the normal physiological functioning of the plant and a multicellular organism. However, pathogens can affect unicellular organisms across the different biological kingdoms. Bacteria and viruses are the common microbes that are infectious and have the capacity to cause diseases in their host. In addition, fungi and protozoans are parasites that are considered as pathogens, Koo (2009). It has been mentioned that food borne pathogens have numerous modes of inhabiting their hosts. Humans come into contact with the foodborne pathogens mainly through certain foods, water, and the environment or even by contacting an infected person. According to Minnesota Department of Health, sources of food borne pathogens include raw food that is mainly of animal origin. Foods falling under this category include meat, ground meat, organ meat, vacuum packaged meat, milk, unpasteurized milk, raw eggs and raw fish. The other source of foodborne pathogens includes fruits and vegetables. The fruits and vegetables may be contaminated by animal waste in the form of manure during application of fertilizer. The fruits and vegetables may be contaminated by how they are handled. The fruits and vegetables might be unwashed when someone consumes them. Unclean water may also wash them, MDH (2010). The other major source of foodborne pathogens is coming into contact with an infected person. This is through the food that comes into contact with others infected by vomit or diarrhea. This applies for cases where an individual was recently ill, as well. The food that is exposed to the factors mentioned is bound to be contaminated and without proper preparation in terms of cooking they in turn can affect the other people. The food included salad or cut fruit, MDH (2010). Microorganisms and Food Spoilage Food spoilage refers to the metabolic process in which food is altered to an unacceptable state for human consumption, Virginia Polytechnic Institute and State University (2012). Spoiled foods are as a result of microbial activity, enzyme degradation, insect damage and insect injury. The elements that show food spoilage include the appearance of food, changes in the food texture and changes in food taste and odour. Different food categories are affected by different microorganisms, storage conditions and handling techniques. The temperature at which meat is stored is the greatest factor that leads to its spoilage. The growth of molds is inhibited at temperatures below 5ºC. High humidity leads to bacterial spoilage of meat. This is noted in ground meat as the intrinsic and extrinsic parameters encourage bacterial growth. Handling of ground meat causes contamination and its spoilage can be detected from bad odour, sour taste, greening and slime. Poultry also exhibits same trends as fresh meat. The microbial load increases with additional processing steps. Bad odour and slime indicate spoilage in poultry. The skin is usually affected first as it encourages bacterial growth. When one considers seafood and most specifically fish, their microbial quality is determined by the quality of water that they were harvested. Unsanitized processing plants majorly cause spoilage in fish. This encourages bacteria that are concentrated on the gills; intestine and outer slime of fish. The gill region is the easiest way to detect spoilage in fish by smelling the odour it produces, Virginia Polytechnic Institute and State University (2012). Vegetables and fruits spoil mainly due to yeast, mold and bacteria. Vegetables get contaminated by surface contamination, during harvesting, packaging, in the processing plant and at the markets courtesy of handling. Fruits are affected by mold and yeast due to the high pH of fruits. The easiest way to detect spoilage in vegetables and fruits it the odour and appearance they exhibit. Dairy products spoil mainly due to yeast, mold and bacteria. When stored in unsuitable temperatures and pH the microorganisms multiply and make the products unsuitable for consumption. The consumption of spoilt food leads to cases of food poisoning. Susceptibility to Food Poisoning Food poisoning can affect anyone. However, certain groups in society are more susceptible to food poisoning than others. Similarly, the effects of food poisoning are seen to differ among several people, particularly between healthy people and vulnerable groups. Vulnerable groups refer to the elderly, disabled persons, infants, persons diagnosed with long-term ailments, pregnant women alcoholics and a variety of groups whose conditions make them prone to foodborne ailments. In the year 2007, the Ad Hoc group carried out an assessment on the increased cases of listeriosis among the elderly groups in the UK. The study showed that the elderly and other vulnerable groups were more susceptible to this foodborne ailment. This was attributed to the likelihood that vulnerable groups have underlying conditions, such as reduced immunity, that makes them more susceptible to listeriosis and other foodborne ailments as compared to able-bodied persons, Ad Hoc Group (2009). Signs and Symptoms of Food Poisoning There is no defined set of foodborne illness symptoms. However, the most common symptoms include diarrhea, vomiting, abdominal discomfort and nausea. In some cases, headaches, fevers, muscle aches and sometimes hallucinations can be seen. In extreme cases, food poisoning victims can exhibit difficulty in breathing, irregular heartbeats and even paralysis. In the case that two different people exhibit similar symptoms after having shared a meal, chances are likely that they are suffering from food poisoning. Medical practitioners always consider food poisoning where they observe vomiting and diarrhea, Commonwealth of Massachusetts (2008). Diagnosis and Prevention of Food Poisoning During the diagnosis of foodborne ailments, health care providers often make enquiries about the symptoms, recent food and water consumption and the patients’ medical history. Further tests may also be conducted, Davis (2009). These tests may consist of a stool culture, vomit sample and a sample of the suspected food, where it exists. These samples are tested and analyzed to determine the presence of infections and diseases. Where symptoms of foodborne diseases appear to be mild, diagnostic tests can be ruled out, National Digestive Diseases Information Clearinghouse (2014). The best prevention practice for food poisoning is cleanliness. The spread of microbial organisms can be mitigated by observing good personal hygiene. Individuals should learn to regularly wash their hand after leaving the washroom and when handling foodstuffs, work surfaces and utensils. In addition, peoples with cuts and sores should also abstain from handling food as dictated by good hygiene practices. Secondly, proper cooking kills harmful microbes in food. Bacteria cannot survive under high temperatures. The third way of preventing food contamination is through chilling food. This ensures that temperatures are rightly maintained to prevent bacterial growth and production of toxins in food. Finally, food handlers should be well aware of proper food handling techniques and methods to prevent cross contamination, Food Standards Agency (2007). Rapid Food Spoilage Detection Biotechnological advancements have significantly simplified the methods for detection of pathogens in food. Neogen’s Soleris detection technology is one such method that detects the presence of spoilage microorganisms much faster than in would take in traditional methods. The system has a unique ready-to-use vial that detects microbial presence by keeping track of chemical reactions and pH changes. Microbial growth medium and samples of about 5ml are mixed in the vial. The Soleris Unit takes note of changes in color and chemical traits of the growth medium as metabolic processes occur. The vial has an agar plug from which optical changes are observed every six minutes. This technology has been proven to give accurate results within 48 hours whereas traditional methods take up to five days. The system has been used to carry out the Direct Yeast and Mold *DYM to test foods affected by mold and yeast such as fruits, meat and milk products, Neogen (2013) . Conclusion Food poisoning has become an ever increasing public health concern in modern societies. Despite the technological advancements, cases of food poisoning still result in the deaths of people. These deaths can only be avoided through hygienic health practices if food handling, preparation and storage. Similarly, losses incurred due to food spoilage can as well be prevented through appropriate food storage methods. . 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(2009) Food Allergies: Clinical Manifestations, Diagnosis, and Management, pp. 236-237 (Retrieved Online) http://meds.queensu.ca/assets/pedsgi/Food_Allergies_-_Clinical_Manifestations_Diagnosis_and_Management.pdf Department of Health, California (2005) Botulism, pp. 1-3 (Retrieved Online) http://www.cdph.ca.gov/healthinfo/discond/Documents/Botulism.pdf Doyle M. Ellin (2007) Microbial Food Spoilage — Losses and Control Strategies, Food Research Institute, p. 3. 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