Introduction to Microbiology
The history of microbiology dates its origin back to 1674 when a Dutch merchant, Antoni van Leeuwenhoek was able to see, for the first time, microbial organisms. The invention of the microscope was, however, the most important step towards the development of microbiology. Microscopic observations made it possible to study and understand bacteria and other microscopic organisms. The discovery of the use of cowpox in the vaccination against smallpox, by Edward Jenner, was a major development in immunity. However, it represented only a small area in the field of microbiology. Therefore, the description of Jenner as the “greatest microbiologist of all time” is extremely biased and totally misplaced because other scientists have made more significant discoveries in microbiology yet have not received such credit.
Louis Pasteur was the French chemist who developed germ theory. He discovered that fermentation occurred due to the multiplication of micro-organisms in liquids. He also discovered that pasteurization could be used as a preservation method. He experimentally showed that meat decayed due to the activity if microbes and used this discovery to argue that multiplication of germs in the body was behind the cause of diseases. He developed a new method of vaccination – weakening germs through prolonged exposure to air made chicken immune to cholera.
Robert Koch was a German doctor who made major contributions in the field of bacteriology. He built on the germ theory by Pasteur to prove that Bacillus anthracis was the causative agent of anthrax. He extracted the bacterium from the tissue of a sheep that had succumbed to anthrax, isolated the organism in pure culture then repeatedly introduced it mice. The mice developed anthrax which made Koch conclude that anthrax is caused by Bacillus anthracis. He also promoted the use of stains and solid media. He published Koch’s postulates used to determine the causative agent of certain diseases.
Bubonic plague was the most common cause of death in the medieval periods of Western Europe. Black Death was the massive outbreak, which occurred between 1348 and 1349. This outbreak massively affected the population, economy and social structure of Western Europe. The 16th and 17th centuries had sporadic episodes of bubonic plague outbreaks but frequent infections occurred in urban centers especially London. The survival rates for bubonic plague was relatively higher than other plagues like pneumonic or septicaemic plague. However, mortality rates were higher among children, the elderly and the poor.
Bubonic plague is a rodent’s disease, particularly rats. Infection occurs when the bacterium, Yersinia pestis, enters the blood stream. It is a vector borne disease transmitted by fleas, which carry the bacterium from the rodents to humans. Bubonic is derived from the word buboes, which means large red swellings. These occur mainly in the groin or the armpits. For a full scale bubonic plague to occur the rats have to be infected with the bacterium and the population of the fleas has to be high enough to transmit the bacillus from the rats to humans and/or to other rats. It was noted that ships from the Middle East were at risk of transporting infected rats, therefore, spreading the disease. It is a common belief that the Black Death was responsible for the deaths of 33-50% of Western Europe’s population.
Some of the public health measures employed in a bid to control the plague included: isolation of infected individuals. Normally, they were sent to hospitals where most of them succumbed to the infection. Suspected ships were quarantined for a certain period time and only released after the plague was over. A whole community could also be isolated with minimized trade and migration.
References
Encyclopedia. (2003). History of Microbiology. Retrieved from Encyclopedia.com: http://www.encyclopedia.com/doc/1G2-3409800277.html
Microbiologybytes. (2005, January 19). A Brief History of Microbiology. Retrieved from Microbiologybytes: http://www.microbiologybytes.com/introduction/History.html
Scott. (2012, December 3). Edward Jenner and the Discovery of Vaccination. Retrieved from University of South Carolina: http://www.sc.edu/library/spcoll/nathist/jenner2.html
Understanding Epidemics. (2013). Historical Epidemics: Bubonic Plague. Retrieved from Understanding Epidemics: http://pcwww.liv.ac.uk/epidemics/HIST_bubonic.htm
