Antibiotic-resistant bacteria“Antibiotics” is the name given to the group of chemicals, particularly in medicine, that stop or inhibit the growth of microorganisms such as fungi, bacteria and parasites, or that they kill the microorganism. However, they are completely ineffective against viruses. There are two types of antibiotics, namely bactericides, which interfere with the cell wall or contents of the bacteria, killing them, and bacteriostatics, which prevent the bacteria from reproducing. They are used to treat bacterial infections in humans and animals. Bacteria are microorganisms made up of single cells and reproduce by mitosis. They usually live in colonies. Some bacteria and other microorganisms produce antibiotics to kill other species, making more resources available. Ironically, it was this that led to the discovery of antibiotics in 1928, when Alexander Fleming noticed that the fungus Penicillium notatum, which had contaminated a sample of pathogenic bacteria, had killed bacterial colonies in a Petri dish. Some bacteria cause disease and are called pathogens. They cause disease by producing toxins that damage body tissues. Others are harmless or even helpful, performing many vital functions in the body, such as aiding digestion. Bacteria are living organisms and as such have the ability to evolve through mutation and natural selection. This is the process by which random genetic mutations create individuals better suited to their environment, who then live to reproduce. The offspring of this individual will then undergo this mutation and thus a species will evolve. One of the major problems facing the medical profession today is the harmful one, which... middle of paper...ics.Bibliography1. (2007). What are antibiotics? - Medical news today. Retrieved March 30, 2014, from http://www.medicalnewstoday.com/articles/10278.php.2. (2007). Antibiotic resistance - Science Daily. Retrieved March 30, 2014, from http://www.sciencedaily.com/articles/a/antibiotic_resistance.htm.3. (2006). Antibiotic resistant bacteria | Better healthcare channel. Retrieved March 30, 2014, from http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Antibiotic_sensitive_bacteria.4. Regina Bailey (2012). Stopping Antibiotic Resistance - Biology - About.com. Retrieved April 4, 2014, from http://biology.about.com/b/2012/04/06/stopping-antibiotic-resistance.htm.5. (2008). Penicillium notatum (mushroom) -- Encyclopedia Britannica. Retrieved April 7, 2014, from http://www.britannica.com/EBchecked/topic/449894/Penicillium-notatum.