Bacteria: These are tiny microorganisms, they cannot be seen with the naked eye. They exist on virtually every living thing or object in the environment i.e. dirt, water, caves, trees, dead animals, and within everybody living on earth. Its nutrition is from its surroundings. We carry bacteria in the body, mainly in the intestines, on the genitalia or on the skin. Bacteria can be good or bad. It can help our immune system but there are bad bacteria which make you become ill. Meningitis is a bacterial infection, this can be life threating to a young baby and is most common in young children. It is an infection of the membranes covering the brain and/or spinal cord, this is a reason it can be life-threatening. MRSA is another big bacteria illness, this commonly affect hospitals and is due to lack of hygiene. Food poisoning is a common cause of illness caused by bacteria. This is because bacteria lives on food. If cooked and food has not reached a high enough temperature to kill off bacteria then it can cause the bacteria to rapidly grow and cause sickness to a person. The types of food poisoning are; salmonella, E. coli, norovirus, campylobacter, listeria, clostridium perfringens. These are also linked with viruses too.
Also most sexual transmitted diseases are a bacterial infection i.e. syphilis, gonorrhea. Also Lyme disease, this is spread by the bite of a deer ticks most common around wooded, rural areas. If untreated it causes an arthritis-like condition that can last for months. Viruses: This is a disease producing agents which are far smaller than bacteria. They are enclosed in a protein coating which makes them more difficult to destroy. These replicate only inside the living cells of organisms. They can infect all types of life forms i.e. plants, animals, and bacteria. The most common virus is the flu, it’s a contagious infection (it spreads from one person to the next). Foot-and-mouth is a virus disease which is caused within an animal. Plant viruses such as mild mottle virus eat away at the flesh of i.e. peppers. This can cause harm onto animals and people if they consume the food. Some viruses can replicate within archaea, these are double stranded DNA viruses with unusual shapes. Chicken pox is another virus illness, this affects normally in children. Fungi: This comes from the plant kingdom but are quite different from green plants.
The basic unit of a fungus is a hypha which is a hollow tube. This spreads out over and into the food material making a visible mesh. Some mass together to create toadstools, releasing spores into the environment. Some fungi can be quite dangerous causing hallucinations but some can even result in death. There are 1.5 million different types of fungi in the world. Out of that only 300 are known to cause illness. Aspergillosis – this normally occurs with a person who has a lung disease or a weakened immune system. Dermatophytes – this in fungal infection to the skin and nail i.e. athletes foot. Fungal keratitis- this is the inflammation of the cornea (the clear front part of the eye). Parasites: A parasite lives in a close relationship with another organism (host) this causes harm. It is dependent on the host for its life functions e.g. viruses are common parasites. It lives, grows and multiplies off the host. A hookworm is a common type of parasite, pets can get these and transfer then onto humans. Hookworms attach in the lining of the small intestine, causing disease and malnutrition as well they eat the nutrition and prevent the host from getting them. Parasites can give off toxins that make the host sick resulting in an infection. Malaria is one of the deadliest parasite diseases, this is why when flying abroad you must ensure all injections against parasites are up-to-date. So there are three types of organisms where parasitic infects; protozoa, helminths and ectoparasites.
Protozoa are singled celled that live and multiply within humans. An infection caused by this is giardiasis, this is caused from drinking water infected with protozoa. Helminths are multi-celled organisms that can live alone or in humans and animals. These are commonly known as flatworms, tapeworms, ringworms, roundworms. Ectoparasites are multi-celled organisms that live or feed of the skin of humans such as mosquitos, fleas, ticks and mites.
When we have an invasion of the body of microorganisms which are not normally present, we call it an infection. This is when germs such as parasites, microbes etc. attack our body and cause harm (disease) or even death unto a host (organism) body. An infection may remain localised in the body (stay in one place) or it may spread through the blood or lymphatic vessels to become systemic (body wide). So something which is linked with ‘infection’ is something called ‘colonisation’. This is the process in the biology by which a microorganism will spread to new areas/part of the body. Colonisation is the development of a bacterial infection on/in an individual. The individual becomes a carrier to the infection but may have no signs or symptoms of illness. They do have the potential to infect others.
Systemic infections affect not just one part but all of the body, examples of this are flu/HIV. And localised infections are limited to one area ear/eye infection.
Identifying poor practise that could lead to infection are fairly simple and basic. Ensuring that you wear clean clothes every day, washing hands very regularly, wearing all correct PPE. Incorrect storing or cooking of foods will lead to infection so you must ensure that things are stored correctly i.e. fresh meat should not be kept on top shelf of the fridge above fruit and veg, contamination of blood could occur. 2.1 What conditions are needed for the effect of growth on micro-organisms? Food is the main source, organisms need food to survive, foods with high protein such as fish and poultry. Warmth is another key factor, anything between 20-40 degrees will really encourage microorganisms to develop and grow, and moisture enables the multiplying process further. Air (usually) although some microorganisms do not need the use of air to spread. So all of these factors seems very every day and very easy for an organism to grow very quickly although a single M.O becomes 2 every 20 minutes. This means the process can take fairly long so regularly cleaning surfaces and storing food correctly will decrease the contamination. 2.2 Infectious organisms that can enter the body are many. They can potentially cause harm to the body, they enter through different openings in the human body. As well as this they can be transferred from mother to baby during pregnancy. The respiratory system – the infectious organisms that cause communicable diseases such as common cold, flu, and pneumonia.
They enter through the nose and then begin to multiple, if not treated right away they can cause other additional problems. The digestive system – with this the organisms are found in food i.e. food poisoning. If food is not correctly cooked at a high enough temperature to enable the bacteria to be killed off. The organisms enter the digestive system and can make you sick when the body is trying to digest the tainted food. Some food poisoning can be fatal if they’re left untreated. Penetrating through the skin – infections organisms that can cause sickness like tetanus and hepatitis C enter the body through the skin. Once entered they start to multiply and can cause more serious problems if untreated. Sexual transmission – some infections such as sexually-transmitted diseases like HIV and gonorrhoea, are transmitted through body fluids such as semen. Once it has entered the body the infection multiplies and can cause complications if it’s not treated. Contact with animals – if you come in contact with an animal that is infected with i.e. rabies the virus can enter your body through the skin. Transferring from mother to child – a woman who is pregnant can transfer lots of kinds of infections such as rubella, German measles, this can be done without realising, and vaccinations for babies once born must be given to prevent the infections.
Infections are a significant problem which humans have to face on a daily basis. They can affect the body in some of the most unpleasant ways. They have multitude causes, some are completely uncontrollable. Some people can have an infection and not even know (asymptomatic infections). There are actually five types of microorganisms called bacteria, viruses, fungi, rickettsia, and protozoa. Microorganisms are normally found in the human body in small amounts and are actually indispensable. Sources of infection can be classified as endogenous and exogenous. In endogenous infections, the agent causing the problem comes from the human body. Some of the microorganisms living here exceed their limits ad start causing damage. This might happen because the immunity is compromised and it is very common in patients who have had surgery or in undernourished people. Exogenous are sources of infections that microorganisms from outside the human body find their way inside and cause illnesses or diseases. Exogenous sources of infections that can be split into three main categories: a human origin, of animal origin and of environmental origin. Animals are a source of infection. If an animal bites you, they can transfer the infection. Water, air and soil are significant other sources of infection. This can be contaminated water from parasites. Air and soil are not sources of infection themselves but they mainly contain non-pathogenic agents that can get contaminated microorganisms carried by humans or animals and contribute in spreading them. Air is one of the most important sources of spreading as we breathe air in.
The term of how an infective agent can be transmitted to a person is the transmission of microorganisms directly from one person to another by one or more reasons. These being: Droplet contact – coughing or sneezing on another person
Direct physical contact – touching an infected person, including sexual contact Indirect physical contact – usually by touching i.e. soil contamination or a contaminated surface. Airborne transmission- if the microorganism can remain in the air or long periods. Fecal-oral transmission – usually from contaminated food or water sources. So transmitting of a microorganism can have many routes in which it can be caught. It can be indirect, via another organism, either a vector (mosquito) or an intermediate host (tapeworm) indirect transmission could involve zoonoses (infectious disease that can be transmitted form non-human animals) or more typically larger pathogens like macro parasites with more complex life cycles. Times when an infection is more likely to occur is when a person has a low immunity or is on long term antibiotic therapy. Poor hygiene when treating wounds or dealing with personal care can aid the transmission of infection. Any contact with bodily fluids, hygiene i.e. dirty services or clothes (contamination).