microbiology

• Viruses are non-living particles that require a host cell to replicate.
• Enzyme immunoassays (EIA) and polymerase chain reaction (PCR) are examples of diagnostic tests.
• Microbiology is the branch of science that deals with microorganisms, which are too small to be visible with the naked eye, including bacteria, viruses, fungi, protozoa and algae, collectively known as microbes or microorganisms.
• Medical microbiology is the study of causative agents of infectious diseases of humans and their reactions to such infections.
• Bacteriology is the science of bacteria, the causative agents of a member of infectious diseases.
• Virology is the science of viruses, non-cellular living systems, capable of causing infectious diseases in man.
• Immunology is the science which concerned with mechanisms of body protection against pathogenic microorganisms and foreign cells and substances.
• Mycology is the study of fungi pathogenic for man.
• Protozoology deals with pathogenic unicellular animal organisms.
• Microorganisms are widely used in food products, beverages, medicines as antibiotics, vaccines, vitamins, enzymes, etc.
• 87% of microorganisms are beneficial to humans, 10% are opportunistic, 3% are pathogens.
• Anthon van Leeuwenhoek (1632 – 1723) was a lens grinder who produced simple (single lens) microscopes.
• Louis pasteur (1822 – 1895) discovered the process of fermentation and developed a method of “pasteurization” to reduce microbial contamination.
• Many human activities pollute our environment, adversely affecting the water we drink, the air we breathe, and the soil in which we grow food.
• Environmental pollution includes air pollution, water pollution, noise pollution, littering, soil contamination, radioactive contamination, thermal pollution, and visual pollution.
• Microbial pollutants include water borne pathogens such as bacteria, viruses, protozoa, and helminths, and infectious disease organisms contaminated drinking water.
• Environmental pollution can lead to diseases such as cholera, typhoid fever, stomach flu, diarrhea, hepatitis, and paralysis.
• Major laboratory investigations for identification of major microbial agents include examining specimens to detect, isolate, and identify pathogens or their products using microscopy, culture techniques, biochemical methods, and immunological (antigen) tests.
• Microscopy can assist in the diagnosis of microbial infections by examining microorganisms for their morphology, motility, and staining reactions.
• Special stains allow for the distinction of microorganisms with unique characteristics such as capsule staining and acid fast staining.
• Culture techniques involve microbial growth in a nutritional solid, liquid, or semi solid medium which increased numbers of organisms.
• Biochemical methods following culture often require the identification of pathogens by their enzymatic and fermentation reactions.
• Immunological (antigen) tests often enable an early diagnosis or presumptive diagnosis of an infectious disease to be made by using specific antibody (antisera or labelled antibody).
• Robert Koch (1843 - 1910) developed pure culture techniques and proved that Bacillus anthracis caused the disease anthrax in cattle.
• Alexander Fleming (1928) discovered Penicillin.
• The 5 Kingdom classification of microorganisms is based on characteristics such as the presence or absence of a nucleus, mitotic division, DNA associated with histones, chromosome number, presence or absence of membrane-bound organelles, such as mitochondria and lysosomes, size of ribosome, cell wall containing peptidoglycan, and more.
• Prokaryotic cells have a nucleus, no mitotic division, DNA associated with histones, one chromosome, no membrane-bound organelles, such as mitochondria and lysosomes, 70S ribosome, and a cell wall containing peptidoglycan.
• Eukaryotic cells do not have a nucleus, mitotic division, DNA associated with histones, more than one chromosome, membrane-bound organelles, such as mitochondria and lysosomes, 80S ribosome, and a flexible membrane.
• Viruses, bacteria, fungi, protozoa, and algae are medically important organisms with different characteristics such as approximate diameter, type of nucleus, presence or absence of a rigid wall containing peptidoglycan, and method of replication.
• Pollution is defined as the introduction into the environment of substances liable to cause harm to humans and other living organisms.