Pathogenic bacteria are microorganisms that contribute to the development of bacterial diseases. There are infectious diseases that are well known in historical context that have caused epidemics, such as plague, smallpox, cholera, typhus, and typhus (Wassenaar, 2009). Special drugs called antibiotics are used to prevent or treat diseases. Antibiotics are chemicals that kill, damage, or inhibit the growth of pathogenic bacteria. The resurgence of anitibiotic consumption began with the discovery of penicillin, which played a significant role in the pharmaceutical industry. According to the American Chemical Society (2004) one of the greatest discoveries is the discovery of penicillin. Before the existence of antibiotics, people died in hospitals just from pathogenic bacteria in their wounds. The history of the use of penicillin as a drug begins in ancient times, when the Egyptians put bread with mold on bleeding wounds. However, it is assumed that the discovery of penicillin as an antibiotic belongs to Alexander Fleming in 1928. The American Chemical Society (2004) states that Alexander Fleming was examining Petri dishes with colonies of pathogenic bacteria when he saw the unusual thing: in the contaminated Petri dish mold bacteria did not grow at all. As a result, he began work on separating the substance that killed several bacteria, but was unsuccessful. Fleming's failed experiments were continued in 1939 by Howard Florey, Ernst Chain and their colleagues at Oxford University. Because of the war, it was difficult for scientists to carry out experiments on the purification of penicillin, while hospitals overcrowded with patients needed medicines capable of curing all bacterial diseases. In 1940 F...... middle of paper ......a cocktail of different antibiotics was used to treat particular bacterial diseases, but even this was not effective enough. The main goal of today's pharmaceutical companies is to find a drug that is as effective as penicillin was in the 1940s. References: American Chemical Society. 2004. The discovery and development of penicillin.http://acswebcontent.acs.org/ (accessed 2 September 2011) Betsy, T. and J. Keogh. 2005. Microbiology demystified. USA: McGraw-Hill Professional Publishing Chemistry of Life. 2011. Discovery of penicillin. http://portal.acs.org/ (accessed 3 September 2011) Mulvey R., AE Simor.2009. Antimicrobial resistance in hospitals: how concerned Wassenaar, T. 2009. Bacterial diseases in history. http://www.bacteriamuseum.org/cms/special-features/bacterial-diseases-in-history.html (accessed September 2, 2011)