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Microbiology and Parasitology


Microbiology is often incorrectly classed as the study of germs or of bacteria. While some microbiologists  may specifically study viruses, also called virology, or bacteria, also called bacteriology, microbiology encompasses the whole of studying microscopic organisms. This includes the study of bacteria, protozoa, fungi, some types of algae, and often viruses.

The origins of microbiology can be traced to scientists positing that small unseeable things might affect other organisms. Anton van Leeuwenhoek was able to observe tiny bacteria in a primitive microscope in the 17th century. Many cite microbiology of medical origin as having been founded by Louis Pasteur and Robert Koch in the mid to late 19th century.

Later discoveries in the 20th century, like the discovery of viruses proved of immense importance to medical use of microbiology. Most physicians today credit microbiology with some of the most important work related to human illness that has ever been conducted.

Medical microbiology is only one facet of the field of microbiology. Other subsections of study in microbiology include applications of the science to the following: Physiology, Genetics, Environmental studies, Evolutionary Biology and Pharmaceutical Studies.

In each case, microbes are studied and knowledge about them contributes to these other disciplines. For example, understanding the basic make-up of microbes, and how they develop and die is part of physiological microbiology. As well, evaluation of how microbes interact with each other in a complex environment enhances our understanding of our environment.

Microbiology in simple applications can also help us understand some of the basic functions of our baking ingredients. For example studies into the behavior of yeast allows us to understand how to effectively use yeast to bake bread. It also helps to explain why our loaf may fall flat.

Scientists in microbiology see the world as composed of almost uncountable numbers of tiny unseen parts that influence us in many ways. The field is constantly uncovering more that may be of benefit to all humans interacting with their environment.

Microbiology is only getting started as a science. Scientists estimate that about 99% of the microbes existing on earth have not yet been studied. This suggests that greater application of microbiology may further help us understand some of the mysteries of life that still daunt us.


Parasitology is the scientific study of parasites. Some parasitology studies evaluate the relationship between parasitic organisms and their hosts. Other studies look for and describe different types of parasites. Parasitology has applications in human and veterinary medicine. The study of parasites draws on other scientific disciplines, such as microbiology, organic chemistry, and cytology.

Though the name parasite has negative connotations, not all parasites adversely affect their hosts. In some cases, parasitology demonstrates how the relationship of a parasite to its host is mutually beneficial, called mutualism. The parasite and the host may gain protection from each otherís presence or provide each other with food. When parasite and host cannot exist apart, their relationship is called symbiotic. The two organisms are equally and mutually dependent upon each other.

Parasitology, when used in applications in human and veterinary medicines, tends to examine the relationship between parasites that invade and cause damage to the animal or human body. For example, insects that are vectors for disease are studied to see to what degree they pass those diseases on to humans or animals. The mosquito is a parasite that affects not only human populations, but also birds and horses. Some mosquitoes carry West Nile Virus, which in severe cases can result in encephalitis and sometimes death. In order to improve medicineís understanding of West Nile Virus, parasitologists must understand the mosquito.

From past studies, parasitologists determined that not all mosquitoes are equally dangerous, and not all carry West Nile Virus. Only female mosquitoes bite, while male mosquitoes drink nectar. More recent parasitology studies have identified that mosquitoes that carry West Nile Virus have a tendency to survive and be present through winter in moderate climates. So from this, we know that the presence of a mosquito in December in the US means more risk to us of contracting West Nile Virus.

In veterinary medicine, parasitologists work specifically to eliminate flea infestation on cats and dogs. Recent technology has evolved to allow dogs or cats to either take a pill a month, or have a spot treatment on their back that either retards fleas from maturing, thus preventing bites, or directly kills fleas that bite. Some fleas can be vectors for diseases. Fleas on rats caused the Black Plague of the Middle Ages. Improved flea protection can minimize health risks and reduce flea infestation, providing relief to both pets and their owners.

Parasitology also studies the one-celled organisms that can make us ill, which can be either bacteria or fungi. Such studies depend on the ability to identify and describe cells, cytology, or microbiology at the microscopic level. Description of these cells and their presence has lead to better detection of certain bacterial and parasitic infections.

Parasitology must concentrate not only on identifying and describing harmful cells, but also on evolving methods for destroying them. From this information, medications are developed to treat specific infections. Understanding parasites led to the understanding of the role of antibiotics in treating bacterial infections, arguably one of the most significant medical developments in history.