Bacteria & Viruses

References http://www.scienceprojectideas.co.uk/facts-about-bacteria-viruses.html http://www.biology.arizona.edu/cell_bio/tutorials/pev/page2.html http://www.netdoctor.co.uk/health_advice/facts/virusbacteria.htm

Bacteria Facts Different bacteria can live at a huge range of temperatures From ice to hot springs, Can even live in radioactive waste Most bacteria are useful – gut bacteria produce vitamins and help people (and animals) digest their food Bacteria in the roots help legumes (plants in the pea and bean family) get nitrogen out of the soil, which helps them to grow

Bacteria Facts Bacteria are used in making: Bacteria produce oxygen – cheese, yoghurt and sourdough bread (see ‘Make Yoghurt and Grow Yeast’). Bacteria produce oxygen – perhaps as much as half of the oxygen in the atmosphere. Bacteria (usually dead or weak ones) are used to make vaccines. Bacteria are used to clean water in sewage plants. Bacteria can help clean up oil spills.

Bacteria Facts http://www.imagebath.com/fequalsma/bacteria/

Bacteria Facts Bacteria can cause food poisoning– this is why chicken needs to be cooked thoroughly Why some food should be kept in the fridge. Bacterial infections can be cured with antibiotics – drugs that kill bacteria

Bacteria Facts Using antibiotics too often, or for diseases that don’t need them, like colds and flu (caused by viruses) can stop the antibiotics working known as antibiotic resistance. MRSA (methicillin-resistant or Multiple-Resistant Staphylococcus Aureus) Is a resistant form of a common bacterium found on the skin, which can cause infections after surgery

The Archaea The methanogenic archaeon, Metanococcus jannaschii: is found 3 km down, at 85 deg C Has 1738 genes, 56% of which are new to science Has bacteria-like genes and operons But with eukaryotic-like information processing and secretion systems and eukaryotic protein synthesis

The Archaea These findings represent the scientific equivalent of opening a new porthole on Earth and discovering a wholly new view of the universe. In decoding the genetic structure of archaea, we were astounded to find that two-thirds of the genes do not look like anything we've ever seen in biology before. This brings to closure the question of whether archaea are separate and distinct life forms. -Dr. J. Craig Venter

Bacteria Facts: Antibotics Antibiotics come from fungi (see ‘Facts About Fungi, Mushrooms and Toadstools’).

Bacteria fun Facts Sympathy for the life of bacteria If you were bacteria: You have 0.001 times as much DNA as a eukaryotic cell. You live in a medium which has a viscosity about equal to asphalt. You have a wonderful "motor" for swimming. Unfortunately, your motor can only run in two directions and at one speed. In forward, you are propelled in one direction at 30 mph. In reverse your motor makes you turn flips or tumble. You can only do one or the other. You cannot stop.

Bacteria fun Facts While you can "learn", you divide every twenty minutes and have to restart your education. You can have sex, with males possessing a sexual apparatus for transferring genetic information to receptive females. However, since you are both going 30 mph it is difficult to find each other. Furthermore, if you are male, nature gave you a severe problem. Every time you mate with a female, she turns into a male. In bacteria, "maleness" is an infective venereal disease. Also, at fairly high frequencies, spontaneous mutations cause you to turn into a female. Eukaryotes have enslaved some of your "brethren" to use as energy generating mitochondria and chloroplasts. They are also using you as a tool in a massive effort to understand genetics. The method of recombinant DNA is designed to exploit you for their own good. There is no SPCA to protect you.

Bacteria fun Facts The last laugh may be yours. You have spent three and a half billion years practicing chemical warfare. Humans thought that antibiotics would end infectious diseases, But the overuse of drugs has resulted in the selection of drug resistant bacteria. They didn't realize that this was only the first battle, and now the war is ready to begin. Humans think this is their era. A more truthful statement would be that we all live in the age of bacteria.

Viruses

Viruses What are viruses? Viruses are too small to be seen by the naked eye. They can't multiply on their own They have to invade a 'host' cell and take over its machinery in order to be able to make more virus particles. Viruses consist of genetic materials (DNA or RNA) surrounded by a protective coat of protein. They are capable of latching onto cells and getting inside them. The cells of the mucous membranes, such as those lining the respiratory passages that we breathe through, are particularly open to virus attacks Because they are not covered by protective skin.

Viral Facts Viruses are simpler than bacteria, made up of genetic code (DNA or RNA) with a protein shell – some scientists do not describe them as being alive. Viruses are 20 to 250 nanometres in size. Viruses can’t reproduce (make new viruses) on their own – they need to take over another cell (plant, animal or human).

Viral Facts Some viruses are useful – Most viruses cause disease – viruses called bacteriophages (means ‘bacteria eater’) kill bacteria and are used to protect people against harmful bacteria in food. Most viruses cause disease – colds and flu are caused by viruses, as well as common diseases like chickenpox, measles, mumps and German measles (rubella). HIV, which causes AIDS, is a virus. Once people have had some viral infections, like chickenpox, it makes them immune from having it again – vaccination creates the same kind of immunity, so can prevent people from getting the viral infections.

Viral Facts The more people who are vaccinated reduces the amount of infection in a population, protecting even those people who are not vaccinated – this is called ‘herd immunity’. Depending on the virus, 85-95% of people need to be vaccinated to protect the rest of the people – this is why vaccination is important. There is no vaccine against colds, as there are so many different viruses that cause colds. Flu vaccines change every year, as there are a number of different flu viruses, and the viruses themselves mutate (change) all the time.

Viral Facts Plants can get virus infections – they can make leaves and flowers change colour, or make leaves and stems twisted. Viral infections cannot be cured with antibiotics – most viral infections, like a cold or flu, or some chest infections, just get better on their own. Viruses are passed on by sneezing and coughing, or by touching someone who has a viral infection – this is why it is important to cough or sneeze into tissues and wash hands regularly when infected with a cold or other viral infection.

How are infections with viruses and bacteria spread? Viral and bacterial infections are both spread in basically the same ways. A person with a cold can spread the infection by coughing and/or sneezing. Bacteria or viruses can be passed on by touching or shaking hands with another person. Touching food with dirty hands will also allow viruses or bacteria from the intestine to spread. Body fluids such as blood, saliva and semen can contain the infecting organisms and transmission of such fluids Example: by injection or sexual contact, is important, particularly for viral infections like hepatitis or AIDS

How to avoid infection Wash your hands thoroughly Often one of the best ways to avoid catching a cold Shaking hands with someone who has a cold is risky So avoid rubbing your eyes or nose afterwards. Food should be cooked or cooled down as quickly as possible. Vegetables and meat must be stored separately and prepared on separate chopping boards. Meat should preferably be served well-done

How to avoid infection Remember that food with these invisible organisms does not necessarily smell bad. Some organisms are killed as the food is cooked, But they can still leave toxic substances that may cause diarrhoea and vomiting. The use of condoms during sexual intercourse reduces the likelihood of spreading sexually transmitted diseases

Treatment Bacterial infections are usually treated with a special antibiotic that only kills the bacterium that has caused the disease. To make sure that you get the right treatment, your doctor may take a sample Swab from the throat or a urine sample.

Treatment Viruses can't multiply until they are inside the body's cells. This is the reason why the treatment of virus infections is usually left up to the patient's own immune system Although it may be hard to accept when the doctor says the only cure is for 'nature to take its course'. The treatment of virus infections such as influenza will usually involve: drinking plenty of water. staying at home. People who go to work or school in this condition not only risk spreading the virus to their colleagues, But Also run a higher risk of catching a bacterial infection.

Treatment taking a painkiller such as paracetamol (eg Panadol) or ibuprofen (eg Nurofen) to bring your temperature down. vaccines have been developed against most viral diseases. The vaccine gives the body some help in quickly and effectively fighting the virus.