Unit 1 - Microbiology (PDF)

UNIT 1 - MICROBIOLOGY 1. Introduction to Microbiology 1 MICROBIOLOGY Learning Outcomes At the end of the session, the students will be able to :- 1. Define microbiology 2. State the purpose of learning Microbiology 3. Explain the importance of microbiology...

UNIT 1 - MICROBIOLOGY 1. Introduction to Microbiology 1 MICROBIOLOGY Learning Outcomes At the end of the session, the students will be able to :- 1. Define microbiology 2. State the purpose of learning Microbiology 3. Explain the importance of microbiology in nursing 4. State the history of microbiology 5. Define the common terminologies in microbiology  MICROBIOLOGY - INTRODUCTION “ Germs” “ Invisible creatures that could harm you” Some “bugs” going around.  MICROBIOLOGY - INTRODUCTION Micro means very small – anything so small that it must be viewed with a microscope. Biology is the study of living organisms bios = living organisms and logy = the study of Microbiology is the study of very small living organisms called microorganisms or microbes. that only can be seen under microscope Definition of Microbiology The study of microorganisms (microbes) and their effects on living organism  TYPES OF MICROORGANISM w Major groups of microorganisms include:- Bacteria Fungus Parasites Viruses Most can only be seen with the microscope! TYPES OF MICROORGANISM TYPES OF MICROORGANISM BACTERIA VIRUSES FUNGI PROTOZOA MICROBIOLOGY - INTRODUCTION Microorganisms have a close association with human; they are in us, on us and nearly everywhere around us. ( part of the human environment especially hospital environment). MICROBIOLOGY - INTRODUCTION Disease causing microorganisms are known as pathogens and microorganism that do not cause disease are known as non-pathogens. Some of the non-pathogens are beneficial to us and some have no effects on us at all (normal flora) This normal flora may cause disease if it gains access to another area of the body. About 3% of known microbes are capable of causing disease. (pathogenic)  MICROBIOLOGY - INTRODUCTION Although microorganisms are very small, they play significant roles in our lives. Approximately 100 trillion microbes are in our body → known as our indigenous microflora (normal flora) and they are beneficial to us. Some microbes produce oxygen by the process known as photosynthesis.  MICROBIOLOGY - INTRODUCTION Many microorganisms are essential in various food and beverages industries → Biotechnology → uses living organisms to make or to modify products e.g. cheese. butter, fish sauces, pickles, meat products, yoghurt, soy sauce. Algae and bacteria serve as food for tiny animals. MICROBIOLOGY - INTRODUCTION Some microorganisms live in the intestinal tracts of animals → aid in the digestion of food and produce substances that are value to the host animal. Some bacteria and fungi are used to produce antibiotics → effective in killing or inhibiting the growth of other microorganisms. MICROBIOLOGY - INTRODUCTION Genetic engineering → antibodies, vaccines, synthesizing important enzymes and hormones e.g. insulin, proteins. Some microorganisms are capable of decomposing industrial waste → bioremediation e.g. oil spill, sewage treatment, water purification.  WHY STUDY MICROBIOLOGY The study of microbiology helps the nurses in to understand: i. How disease producing microorganisms enters the body ii. Exit from the body iii. How they spread from person to person iv. The principles of disinfection v. Importance of proper collection of specimens vi. How antibiotics and vaccines used in the treatment and prevention of disease  IMPORTANCE OF MICROBIOLOGY IN NURSING The nurses has an important role in infection control by practicing prevention activities: i. Educating patients – control of infectious disease → Learning how diseases are transmitted, the sources and how to prevent it. ii. Awareness of the risks of nasocomial infection and take steps to protect both the patient and themselves. → Using appropriate barrier precaution. ii.Understanding immunization and disease control → Vaccines  History of Microbiology 18  History of Microbiology Few scientists known for their contributions in the field of microbiology and immunology Principle of microscope was discovered by Jansen in 1609 19  History They are optician Contributions to lens manufacturing. The 1st were making Carl Zeiss ( 1816 – 1888) simpler microscopes with one lens in year 1885. Ernst Karl Abbe (1840 – 1905)  Antonie Philips van Leeuwenhoek (1632 –1723) A Dutch scientist The Father of Microbiology First person to see and describe microbes. 21  Antonie Philips van Leeuwenhoek known for his work on the improvement of the microscope. 22  Antonie Philips van Leeuwenhoek First to observe and describe single celled organisms, which he originally referred to as animalcules, and which we now refer to as microorganisms First to record microscopic observations of muscle fibers, bacteria, spermatozoa and blood flow in capillaries (small blood vessels) 23 Leeuwenhoek’s Microscope  Joseph Lister Joseph Lister, UK (1827 – 1912) Father of Antiseptic surgery An English surgeon found carbolic acid called phenol can kill bacteria. This solution is being use to clean the equipment in operation theater. This technique is called aseptic technique to prevent from infection. 25 Louis Pasteur (1822 – 1895) French biologist and chemist. Steam Sterilizer Autoclave Hot Air Oven  Louis Pasteur 1st studies – disease could arise from microbes. Discovered about fermentation Introduced the terms ‘aerobes’ and ‘anaerobes’. Developed the process of pasteurization – kill pathogens in many types of liquids. - Discovering that weak forms of micro could be used as an immunization / vaccination - Studied anthrax, Rabies and chicken cholera (Failed)  Robert Koch (1843 – 1910) Robert Koch, a German physician. Father of Bacteriology → made significant contributions to the germ theory of disease. → developed methods of fixing, staining and cultivating bacteria. → discovered the bacterium that causes tuberculosis and cholera. → work on tuberculin in diagnosing tuberculosis. Staining Technique Culture Technique Robert Koch In 1882, he discovered the tubercle bacillus & the cholera vibrio. In 1905, he was awarded Nobel Prize in Physiology and Medicine. The lifelong achievements of Robert Koch are: Discovery of use of solid medium in bacteriology Discovery of causative agents of Tuberculosis and Cholera Koch’s postulates 30  Koch’s Postulates Koch's Postulates → criteria designed to establish a causal relationship between a causative microbe and a disease Koch's Postulates are used to prove the cause of an infectious disease. Figure 14.3.1  Discovery of Bacteria in 19th century Year Organism Discovered by 1874 Mycobacterium leprae Hansen 1879 Neisseria gonorrhoeae Neisser 1882 Mycobacterium tuberculosis Robert Koch 1883 Vibrio cholerae Robert Koch 32  Antimicrobial Agents Antimicrobial Agents: Agents to kill microbes without damaging the body tissues. Alexander Fleming, Scotland (1928) discovered penicillin Selman Waksman, Ukraine (1944) discovered streptomycin First human disease proved to be caused by virus – yellow fever Chemotherapy: Treatment of disease by using chemical means Problems Toxicity of drugs Resistance of bacteria to drugs 33  Ignaz Semmelweis, (1847) states that the fever after giving birth is cause by the infection from person hands who handle the process. → peurperal fever Edward Jenner (1849 - 1923) English Scientist “Father of Immunology” Credited as pioneer of smallpox vaccine Smallpox  John Snow (1854) An English Surgeon has found that water is the source of infection for Cholera (Taun) which manifestation by vomiting and diarrhoea.  Walter Read (1851 – 1902) An army Surgeon confirm that protozoa can cause malaria. Malaria is a parasitic disease that involves high fevers, shaking chills, flu-like symptoms, and anemia. Malaria is caused by a parasite that is passed from one human to another by the bite of infected Anopheles mosquitoes.  Modern Stage - 1882 and above Sir Alexander Fleming (1929) Scientist who found antibiotic Penicilin prevent fungus Penicillium and bacteria infection. Modern Stage - 1882 and above Salk (1953) Salk has found vaccine for yellow fever. Modern Stage - 1882 and above Sabin (1955) He has found vaccine for poliomyelitis. Poliomyelitis is a viral disease that can affect nerves and can lead to partial or full paralysis Poliomyelitis is a disease caused by infection with the poliovirus TERMINOLOGIES IN MICROBILOGY  COMMON TERMINOLOGIES Aerobic microorganism A microorganism that is able to live and grow in the presence of oxygen e.g. Pseudomonas Anaerobic microorganism A microorganism that is able to live and grow in the absence of oxygen e.g. Clostridium tetani Commensals An microorganisms that lives in or on another organism without harming it and that benefits from the relationship. COMMON TERMINOLOGIES Antigen Any substance that the body regards as foreign or potentially dangerous. Antibody A protein substance produced by lymphocytes in response to an antigen; it protects the host in some manner. COMMON TERMINOLOGIES Antibiotic Substance derived from one microorganism that kill or inhibit the growth of other microorganisms. Vaccine A substance that contains an antigen to which the immune system responds.  COMMON TERMINOLOGIES Antiseptic A chemical agent that can be safely used externally on tissues to destroy microorganisms or inhibit their growth. Antisepsis The process of preventing by inhibiting or arresting the growth and multiplication of microorganisms. Disinfectant Chemical substance that prevents infection by killing microorganisms except spores.  COMMON TERMINOLOGIES Asepsis A condition free from germs / microorganisms. Sepsis The presence of pathogens or their toxins in the bloodstream; and can cause septic shock.  COMMON TERMINOLOGIES Colonization Is the process where the microorganisms become resident flora, grow and multiply but do not cause disease. Inflammation The body’s defensive response to tissue damage caused by microbial infection. Infection The presence and multiplication of a pathogen on or within the body.  COMMON TERMINOLOGIES Primary infection Infection in a previously healthy person. Secondary infection Infection that immediately follows a primary infections. Super-infection An overgrowth of one or more particular microbes and often antibiotic-resistant microbes. Latent-infection An infection that does not produce visible signs of a disease but may be able to transmit to another host. INFLAMMATION & INFECTIONS  COMMON TERMINOLOGIES Disease A disturbance in the state of health wherein the body cannot carry out all its normal functions. Communicable disease Infectious disease that can be spread fro one host to another.  COMMON TERMINOLOGIES Acute A disease that having a sudden onset and short duration. Sub-acute A disease that is intermediate between an acute and a chronic Chronic A disease that develops more slowly than an acute disease is usually less severe and persists for a long period.  COMMON TERMINOLOGIES Microorganism Very small organisms; usually microscopic; also called microbes; includes viruses, bacteria, protozoa and fungi. Pathogen Is a microorganism that causes disease. Non Pathogen Is a microorganism that does not cause disease. Normal flora Microorganism that normally reside on / in human under normal circumstances and do not cause disease. PATHOGENS  COMMON TERMINOLOGIES Endogenous An infection caused by opportunistic microorganisms already present in the body Exogenous An infection caused by microorganisms that enter the body from the environment. Fomites An object that may be contaminated with infectious agents.  COMMON TERMINOLOGIES Endemic A disease that occur continuously in a particular population. Epidemic Occurrence of an infectious disease or condition that attack many people at the same time in the same geographical area.  COMMON TERMINOLOGIES Carrier A person who harbors a specific pathogenic organism but does not show any signs and symptoms of the disease and who is potentially capable of spreading the organisms to others. Host A person or animal which is infected with the microorganisms. Reservoir Any person, animal, plants, soil or substance in which the infectious agent live and multiplies / harbour.  COMMON TERMINOLOGIES Transmission Transfer of anything, as a disease or hereditary characteristics. Vector An insect or animal that spreads pathogens. Virulence Ability to produce disease VECTOR BACTERIAL VIRULENCE FACTORS  COMMON TERMINOLOGIES Immunity Protection from disease especially infectious disease. Toxin A poisonous substance produced by a microorganism. Toxoid Ability to produce disease Vaccine A substance that contains an antigen to which the immune system responds.  COMMON TERMINOLOGIES Sterilization Process of completely removing or destroying all microorganisms on a substance e.g. on surgical instruments. Isolation Practices that prevent the transmission of pathogens from one host to another  COMMON TERMINOLOGIES Incubation period The time from the moment of infection to the appearance of the first symptoms. Window period Is the time between first infection and when the test can reliably detect that infection. Zoonosis Any disease caused by animals to human.