Intro to Microbiology - Chapter 1 PDF

Microbiology MICROBIOLOGY Joy R. Oliveros, MSES WITH DISEASES BY BODYNat. SYSTEM SECOND Sci. Dept., CAS EDITION  The Scope of Microbiology Microbiology: The study of very small living things or organisms - too...

Microbiology MICROBIOLOGY Joy R. Oliveros, MSES WITH DISEASES BY BODYNat. SYSTEM SECOND Sci. Dept., CAS EDITION  The Scope of Microbiology Microbiology: The study of very small living things or organisms - too small to be seen without magnification Microorganisms or microbes- these microscopic organisms Commonly called “germs, viruses, bacterial agents…” but not all cause disease and many more are useful or essential for human life  Although tiny in size these organisms form the basis for all life on earth. Microorganisms and their activities are vitally important to virtually all processes on Earth. Microorganisms matter because they affect every aspect of our lives – they are in us, on us and around us. Microorganisms are very important to the environment, human health and the economy. These microbes play key roles in nutrient cycling, biodegradation/biodeterioration, produce the soil in which plants grow the cause and control of disease, and biotechnology. in many ways: making life-saving drugs, the manufacture of biofuels, cleaning up pollution, and producing/processing food and drink. fix the atmospheric gases that both plants and animals use. These microbes Have many commercial applications Used in the synthesis of chemical products – acetone, organic acids, enzymes alcohol and many drugs food industry also uses microbes in producing vinegar, pickles, alcoholic beverages, soy sauce, buttermilk, cheese, yogurt and bread Produce cellulose, digestive aids, drain cleaner, therapeutic substances such as insulin Harmful Microorganisms Disease and decay are neither inherent properties of organic objects, nor are caused by physical damage, it is microorganisms that bring about these changes. We are surrounded by bacteria, viruses, and fungi. Many microorganisms cause diseases in cattle, crops and others are known for entering human bodies and causing various diseases. Examples of familiar human diseases are: Bacteria: pneumonia, bacterial dysentery, diphtheria, bubonic plague, meningitis, typhoid, cholera, salmonella, meningococcal Virus: Chickenpox, measles, mumps, German measles, colds, warts, cold sores, influenza Protozoa: amoebic dysentery, malaria, Fungi: ringworm, athlete’s foot Useful Microorganisms As decomposers, bacteria and fungi play an important role in an ecosystem. They break down dead or waste organic matter and release inorganic molecules. Green plants take these nutrients which are in turn consumed by animals, and the products of these plants and animals are again broken down by decomposers. Yeast is a single-celled fungus that lives naturally on the surface of the fruit. It is economically important in bread-making and brewing beer and also in the making of yoghurt. Branches of Microbiology There are various different branches of microbiology, and these include the following: 1. Bacteriology- The study of bacteria 2. Mycology –The study of fungi 3. Phycology- The study of photosynthetic eukaryotes. (Algae- Seaweed) 4. Protozoology – The study of protozoa (Single-celled eukaryotes) 5. Virology- The study of viruses, non-cellular particles which parasitize cells. 6. Parasitology- The study of parasites which include pathogenic protozoa certain insects and helminth worms. 7. Nematology- The study of nematodes.  The Origin and Evolution of Microorganisms Phylogeny- the degree of relatedness between groups of living things Based on the process of evolution- hereditary information in living things changes gradually through time; these changes result in structural and functional changes through many generations Two preconceptions: All new species originate from preexisting species Closely related organisms have similar features because they evolved from a common ancestor Phylogeny usually represented by a tree- showing the divergent nature of evolution  Introduction to Microbiology How Can Microbes Be Classified? Carolus Linnaeus (Swedish) developed taxonomic system for naming plants and animals and grouping similar organisms together in 1735 Scientific names are Latin, assigns each organisms 2 names Genus – is the first name, followed by Species – Ex: Staphylococcus aureus Escherichia coli  Taxonomy: Naming, Classifying, and Identifying Microorganisms Microbial nomenclature- naming microorganisms Taxonomy- classifying living things Identification- discovering and recording the traits of organisms so they can be named and classified  Assigning Specific Names The binomial system of nomenclature The generic (genus) name followed by the species name Generic part is capitalized, species is lowercase Both are italicized or underlined if italics aren’t available Staphylococcus aureus  Introduction to Microbiology How Can Microbes Be Classified? Leeuwenhoek’s microorganisms grouped into six major characteristics, as follows: 1. Fungi 2. Protozoa 3. Algae 4. Bacteria 5. Archaea 6. Virus 7. Animal parasites  Cellular Organization Eukaryotic - organisms whose cells contain a nucleus and other membrane-bound organelles, may be either single-celled or multicellular. Example: animals, plants, fungi, and protists, most algae.  Cellular Organization Prokaryotic - organisms whose cells lack a nucleus and other organelles, small, single-celled organisms that have a relatively simple structure. Example: bacteria, algae, archea  1. Fungi Eukaryotic (have membrane-bound nucleus) May be unicellular or multicellular Obtain food from other organisms Possess cell walls – composed of chitin fungi are responsible for breaking down organic matter and releasing carbon, oxygen, nitrogen, and phosphorus into the soil and the atmosphere atmosphere. Composed of Molds – multicellular; have hyphae; reproduce by sexual and asexual spores Yeasts – unicellular; reproduce asexually by budding; some produce sexual spores Mushrooms  2. Protozoa Single-celled eukaryotes Similar to animals in nutrient needs and cellular structure Live freely in water; some live in animal hosts Asexual (most) and sexual reproduction Most are capable of locomotion by Pseudopodia – cell extensions that flow in direction of travel Cilia – numerous, short, hairlike protrusions that propel organisms through environment Flagella – extensions of a cell that are fewer, longer, and more whiplike than cilia  3. Algae Unicellular or multicellular eukaryotic Photosynthetic Cell wall composed of cellulose Simple reproductive structures Abundant in fresh and salt water, soil Need light and air for food production Produce oxygen and carbohydrates – they play important role in the balance of nature.  4. Bacteria Unicellular and lack nuclei Prokaryotic Much smaller Several shapes: coccus, bacillus, spiral soil, water, plants, animals, radioactive waste, deep in the earth's crust, arctic ice and glaciers, and hot springs. Reproduce by binary fission Bacteria – cell walls contain peptidoglycan; some lack cell walls; they manufacture their own food most do not cause diseases and some are beneficial  5. Archaea first prokaryotes were adapted to the extreme habitat or conditions of earth. prokaryotic archaea evolved from gram- positive bacteria Highly diverse and abundant and includes a number of “extremophiles” that thrive in such environments as hot springs, salt lakes, and submarine volcanic habitats Reproduce by binary fission Archaea – have cell walls, lack peptidoglycan Not known to cause disease in humans  6. Virus submicroscopic infectious agent that is considered living only when they multiply inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms A virus cannot replicate alone; instead, it must infect cells and use components of the host cell to make copies of itself.  7. Multicellular Animal Parasites Although they are not strictly microorganism, they are of medical importance 2 major groups of parasitic worms: 1. flatworms 2. roundworms Collectively called helminths  Classification of Microorganisms Before the existence of microbes are known, all organisms are grouped into either animal kingdom or plant kingdom. When microorganisms were discovered in the late 17th century, a new system of classification was needed. In 19 78, Carl Woese devised the classification based on the cellular organization of the organisms. 3 domains 1. Bacteria (cell walls contain peptidoglycan) 2. Archaea (cell walls present, lack peptidoglycan) 3. Eukarya – which includes a. Protists (slime molds, protozoa and algae) b. Fungi ( yeasts, molds, mushrooms) c. Plants ( mosses, ferns, conifers and flowering plants) d. Animals ( sponges, worms, insects and vertebrates)  A Brief History of Microbiology One of the most important discoveries in the history of biology occurred in 1665 with the help of a simple microscope. Robert Hooke, an Englishman, was observing a thin slice of cork – that life’s smallest structural units were “little boxes”- he called “cells”. He was able to improve a compound microscope (with 2 lenses) and was able to see individual cells and that discovery marked the beginning of a cell theory – the theory that all living things are composed of cells. Then, Anton Van Leeuwenhoek, a Dutch scientist was the first to actually observe live microorganisms through magnifying glass, in the year 1673 and 1723.  A Brief History of Microbiology Until recent centuries it was widely believed that living organisms can arise spontaneously in decomposing organic matter. For visible organisms, this notion was dispelled in the 17th century. When Redi demonstrated that the appearance of maggots in decomposing meat depended on the deposition of eggs by flies. However, the idea of spontaneous generation persisted for the new world of microbes. The answer for spontaneous generation has been shown by Spallanzani (1729-1799) who introduced the use of sterile culture media.  Theory of Biogenesis In 1858, Rudolf Virchow, a German scientist challenged spontaneous generation with the concept of biogenesis – which claim that living cells can arise only from preexisting living cells. Arguments about spontaneous generation continued until 1861, when the issue was resolved by Louis Pasteur, a French scientist. Series of ingenious experiments, Pasteur showed that microorganisms can be present in non-living matter – on solids, liquids and in the air. Also, Pasteur demonstrated that microbial life can be destroyed by heat. These discoveries form the basis of aseptic techniques – techniques that can prevent contamination – which is now the standard practice in the laboratories and many medical procedures.  The Golden Age of Microbiology For about 60 years, beginning with the work of Pasteur, there was an explosion of discoveries in microbiology. The period from 1857 to 1914 has been appropriately named The Golden Age of Microbiology. During this period, there were rapid advances lead by Pasteur and Robert Koch that lead to the establishment of microbiology as a science. Discoveries included 1. the agents of many diseases and 2. the role of immunity for the prevention and cure of diseases 3. studied the chemical activities of microorganisms 4. improved techniques in microscopy and culturing microorganisms 5. developed vaccines and surgical techniques Milestone in Microbiology. Highlighting those that occurred during the Golden Age of Microbiology. It was during this period that numerous discoveries led to the establishment of microbiology as a science.  Louis Pasteur A. Fermentation It is the process of central metabolism in which an organism converts a carbohydrate, such as starch or sugar, into an alcohol or an acid in the absence of air or oxygen. This is used to make wine and beer. the process in which a substance breaks down into a simpler substance. Microorganisms like yeast and bacteria usually play a role in the fermentation process, creating beer, wine, bread, kimchi, yogurt and other foods. B. Pasteurization Pasteur’s solution to the spoilage problem was to hear the beer and wine just enough to kill most of the bacteria that caused the spoilage. It is commonly used to kill spoilage and potentially harmful bacteria in milk as well as in some alcoholic drinks. involves heating liquids at high temperatures for short amounts of time. Pasteurization kills harmful microbes in milk without affecting the taste or nutritional value.  The Germ Theory of Disease The germ theory of disease is the currently accepted scientific theory for many diseases. It states that microorganisms known as pathogens or "germs" can cause disease. These small organisms, too small to be seen without magnification, invade humans, other animals, and other living hosts. states that many diseases are caused by microorganisms such as bacteria, viruses, protozoa, or fungi. These diseases are caused by the growth and replication of microorganisms. The germ theory of disease was devised by Louis Pasteur. Louis Pasteur developed attenuated vaccines ( consists of live, whole bacterial cells or viral particles)  Definition of Life What characteristics must an organism have in order to considered alive?  Metabolism: Transformation of energy by converting chemicals and energy into cellular components (anabolism) and decomposing organic matter (catabolism). Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life.  Reproduction: The ability to produce new individual organisms either asexually, from a single parent organism, or sexually, from at least two parent organisms.  Types of Microorganisms Based on Acquiring Nutrition Autotrophic - are the producers in the food chain, they create their own nutrients and energy. Example: bacteria, fungi, algae Heterotrophic - living organism that eats other organisms for their energy source, they consume producers or other consumers. Example: bacteria, fungi, yeast Saprophytic - microorganism that lives and feed on wastes and dead or decaying organic matter. Example: fungi, mushrooms, molds, bacteria  Why Microbiology is important to Nurses? Microbiology is an integral part of nursing studies and is significant part of nursing profession. Microbiology encompasses the study of microorganisms which cause infectious diseases. The ability to identify and understand these basic properties of specific microorganism is essential for everyone in the health profession especially the nurses who play a vital role in patient care. Nurses are responsible for implementing appropriate measures to reduce hospital infections, especially with multidrug resistant bacteria. This helps them to understand bacterial dissemination and infectious disease control, since nurse practitioners are independently diagnosing and treating infectious disease.  Why Microbiology is important to Nurses? Nurses must have sufficient education and training in microbiology to perform many roles within clinical nursing practice administering antibiotics, collecting specimens, preparing specimens for transport and delivery, educating patients and families, communicating results to the healthcare team, and developing care plans based on results of microbiology studies and patient immunological status