Bacterial and Mycotic Diseases
Bacteria and fungi are microscopic organisms which are ubiquitous in nature and are widely present in soil, fresh and salt water, air, vegetation, human beings and animals. Many of them are capable of causing diseases in man, animals, fishes and even in insects. The study of these microorganisms is called Microbiology.
Examination of bacteria and fungi The microscope is an essential tool for observing microbes which can not be seen by naked eyes. The unit of measurement employed in microbiology is the micron or micrometer (one millionth of a meter). A light microscope can enlarge the objects (bacteria and fungi) up to 100 times. Bacteria are examined under oil immersion (100x) while fungi can be examined at 10× or 45 × under the microscope. In bacteria, Grams staining (the stain goes in the name of Christian Hans Grams) is used to differentiate and identify bacteria as Gram’s positive (purple) and Gram’s negative (pink). Phase contrast microscopy can be used to study finer details of the unstained bacteria. In fungi, KOH (10%) mount of sample or lactophenol blue stained samples are used to examine the type of fungi.