Microbiology is the scientific study of microscopic organisms, either unicellular (single cell), multicellular (cell colony), or acellular (lacking cells) including protozoans, yeasts, algae, molds, microscopic fungi, bacteria, and viruses. Microbiology is concerned with the structure, function, and classification of these organisms and with ways of controlling and using their activities.
Microbiology encompasses numerous sub-disciplines including virology, mycology, parasitology, and bacteriology. Its foundations were established in the later 19th century, with the work of Louis Pasteur and Robert Koch. Since then, many disease-causing microorganisms have been identified and means of controlling their harmful effects have been developed. In addition, means of channeling the activities of various microorganisms to benefit medicine, industry, and agriculture have been discovered. Molds, for example, produce antibiotics, notably penicillin.
Modern microbiology. The branches of microbiology can be classified into pure and applied sciences. Both general microbiology and its specialized branches are developing extremely vigorously. There are three fundamental reasons for such development. First, microbiology has had the advantage of a large number of new methods of research, through advances made in physics, chemistry, and engineering. Second, the practical usefulness of microorganisms has increased sharply since the 1940ís. Third, microorganisms are being used to solve some of the most important theoretical problems of biology, such as heredity and variability, the biosynthesis of organic compounds, and metabolic regulation.
Medical microbiology related to applied sciences is a branch of medicine concerned with the prevention, diagnosis and treatment of infectious diseases. There are four kinds of microorganisms that cause infectious disease; bacteria, fungi, parasites and viruses. In addition, this field of science studies various clinical applications of microbes for the improvement of health as well.
A microbiologist examining cultures under a stereoscope.
A medical microbiologist studies the characteristics of pathogens, their modes of transmission, mechanisms of infection and growth. Using this information a treatment can be devised. Medical microbiologists often serve as consultants for physicians, providing identification of pathogens and suggesting treatment options. They may also assist in preventing or controlling epidemics and outbreaks of disease. Not all medical microbiologists study microbial pathology; some study common, non-pathogenic species to determine whether their properties can be used to develop antibiotics or other treatment methods.
Exercise 9. Fill in the gaps with prepositions from the box below.
Microbiological culture is the primary method used for isolating infectious disease for study _______the laboratory. Tissue or fluid samples are tested for the presence of a specific pathogen, which is determined ________ growth in a selective or differential medium.
The 3 main types of media used for testing are:
∑ Solid culture: A solid surface is created using a mixture of nutrients, salts and agar. A single microbe on an agar plate can then grow into colonies (clones where cells are identical to each other) containing thousands ________ cells. These are primarily used bacteria and fungi.
∑ Liquid culture: Cells are grown inside a liquid media. Microbial growth is determined by the time taken for the liquid to form a colloidal suspension. This technique is used _________ diagnosing parasites and detecting mycobacteria.
∑ Cell Culture: Human or animal cell cultures are infected with the microbe of interest. These cultures are then observed to determine the effect this new microbe has _______ the cell. This technique is used for identifying viruses.