Introduction to Microbiology (2) PDF

INTRODUCTION TO MICROBIOLOGY MICROBIOLOGY- NURS1111 Objective 1. Give a brief overview of the 2. Define 3. Classify historical microbiology microorganisms development of microbiology; 4. Explain the...

INTRODUCTION TO MICROBIOLOGY MICROBIOLOGY- NURS1111 Objective 1. Give a brief overview of the 2. Define 3. Classify historical microbiology microorganisms development of microbiology; 4. Explain the 6. Discuss 5. Explain the laboratory safety difference in importance of and use of cellular structure micro-organisms laboratory of eukaryotic and as agents of equipment. prokaryotic infectious diseases microorganisms (Lab) Definition of microbiology Microbiology is the Microbe / study of: Microorganism are Microscopic living forms minute living being (Bacteria) large & diverse group of Organisms that live in other microorganisms that exist in cells (Viruses, Bacteria) single cells or clusters Macroscopic forms (fungal molds, parasitic worms) Microorganisms / Microbes located almost everywhere TYPICALLY TOO SMALL TO only a small % are UNICELLULAR SEE WITH UNAIDED EYE pathogens most involved in environmental /ecosystem balance: FUNGI PROTOZOA ALGAE breakdown waste fix nitrogen photosynthesis – foundation of food chain BACTERIA & ARCHAEA VIRUSES digestion in animals vitamin production Overview of Microbiology Relatively young discipline developed in 19th century Since then, it has developed rapidly, spawning new sub-disciplines Bacteriology , Virology , Immunology Mycology, Parasitology Microbiology Microbiology have determined the course of history because of the disease they cause New infectious disease appear due to – Lifestyle changes – Travel – Improvement in isolation techniques New and emerging infection SARs, Zika, Dengue, Pandemics - SARS-COVID-2 Ebola, Cholera, Syphilis, Epidemics of Ebola, Measles…??? chikungunya, Zika and other infectious diseases were the norm. Human immunodeficiency virus (HIV)/AIDS, first identified in 1981 Consider their economic impacts The impact of a new and dangerous infectious disease The impact of a new and dangerous infectious disease: monopolize governmental activities The Jamaican economy contracted by an estimated cause fear and hysteria 5.7 per cent in the January The price of freedom in a to March 2021 quarter, have a significant impact largely due to the impact of COVID-19 world (Jamaica Observer, Tuesday, April the coronavirus (COVID-19) 13, 2021) on the economy pandemic. throughout the world (Dr Wayne, Henry, PIOJ, 2021) freedom of movement of people Microbiology Impact on Human Health Balance of Nature - food source, play a role in decomposition, help other animals digest grass (cattle, sheep, termites). Environmental – provide safe drinking water; development of biodegradable products; use bacteria to clean up oil spills, etc. – called bioremediation. Industrial – foodstuffs (beer, wine, cheese, bread), antibiotics, insulin, genetic engineering Agricultural - research has led to healthier livestock and disease-free crops.  Production of Foods: Microbes are a key component in both home and industrial food preparation. Lactic acid bacteria - make yogurt, cheese, sour cream, buttermilk and other fermented milk products. Vinegars are produced by bacterial acetic acid fermentation. Yeast - manufacture of beer, wine, leavening of breads. also fermentation to convert corn and other vegetable carbohydrates into ethanol to make beer, wine, or gasohol; but bacteria are the agents of most other food fermentations. Other fermented foods include soy sauce, sauerkraut, dill pickles, olives, salami, cocoa and black teas. Beneficial Effects of Microorganisms Decomposition or biodegradat their ability to recycle the primary ion elements that make up all living systems, Nitrogen fixation results in the breakdown of complex organic materials to forms of carbon that can be used by other organisms. slowly or not at all, metabolic processes of fermentation and There is no naturally-occurring respiration, organic molecules are organic compound that cannot me eventually broken down to degraded although some synthetic CO2 which is returned to the compounds such as teflon, atmosphere. styrofoam, plastics, insecticides and pesticides  THE MICROSCOPE Van Leeuwenhoek microscope. The original made in 1673 could magnify the object being viewed almost 300 times. The object being viewed is brought into focus with the adjusting screws. (The replica was made according to the directions given in the American Biology Teacher 30.537,1958.) Note its small size.  MICROSCOPES VARIOUS TYPES OF MICROSCOPES ARE AVAILABLE FOR USE IN THE MICROBIOLOGY LABORATORY. THE MICROSCOPES HAVE VARIED APPLICATIONS AND MODIFICATIONS THAT CONTRIBUTE TO THEIR USEFULNESS Types of Microscope The light microscope. fluorescent microscope uses dark‐field ultraviolet microscope light as its , which is light source. used to electron observe live microscope spirochetes is a beam of electrons phase‐ contrast Live, unstained organisms are seen clearly with this microscope  Brief History of Microbiology Robert Hooke 1635-1703) – Invented the compound microscope – Posited the Cell theory all living things are composed of cells. – First scientist to observe microorganisms. – He mentioned microscopic fungi in 1665 – Microscope however lacked resolution to see microbes clearly History Anton van Leeuwenhoek 1632- 1723 – Dutch merchant – Possibly the first to see and describe various microorganisms – Between 1673-1723 constructed more that 400 microscopes Anton van Leeuwenhoek’s letter to the royal society in London after seeing microbes "...Very many little animalcules, whereof some were roundish, while others a bit bigger consisted of an oval. On these last, I saw two little legs near the head, and two little fins at the hind most end of the body. Others were somewhat longer than an oval, and these were very slow a-moving, and few in number. These animalcules had diverse colours, some being whitish and transparent; others with green and very glittering little scales, others again were green in the middle, and before and behind white; others yet were ashed grey. And the motion of most of these animalcules in the water was so swift, and so various, upwards, downwards, and round about, that ’twas wonderful to see....“ HISTORY Louis Pasteur (1822-1895) French chemist and microbiologist. Made significant contributions to the field Father of microbiology Discovered microbes involved in fermentation (Pasteur effect) Pasteurization (sterilization process for wine) Disproved theory of spontaneous generation Discovered vaccine for anthrax and Rabies History continued Robert Koch (1843-1910) Father of modern bacteriology (Nobel prize 1905) provided proof that a bacterium causes anthrax using experimental steps now called the Koch’s Postulates Contributed to Germ theory He was the first to use agar as solid culture medium in bacteriology. History continued Ignaz Semmelweis (1818-1865) Hungarian physician demonstrated the importance of disinfection Proved value of handwashing Used chlorinated lime to reduce death on delivery ward.  Joseph Lister (1827-1912) Consider father of antisepsis Scottish surgeon used phenol to reduce postoperative infections The concept od disinfection used to prevent hospital acquired infections History continued Paul Ehrlich (1854-1915) German scientist, father of chemotherapy Introduced the methods of staining cells and tissues Identified the acid-fast property of tubercle bacillus Introduced the concept of minimum lethal dose Developed salvarsan, an arsenical compound (Magic bullet) against the syphilitic spirochete  John Snow (1813-1858) – "father of field epidemiology.” Conducted studies twenty years before the development of the microscope, to discover the cause of cholera and to prevent its recurrence…Broad Street pump (CDC) History continued Edward Jenner’s (1749-1823)vaccine – field of immunology In science credit goes to the man who convinces the world, not the man to whom the idea first occurs. —francis galton https://www.ncbi.nlm.nih.gov/pmc/articles/PM C1200696/ History continued Mary Secole Florence Nightingale Mary Jane Grant (1805- Florence Nightingale (1820- 1881) 1910) Hometown: Kingston, Jamaica known as “The Lady With the Occupation: Nurse and Lamp,” business woman British nurse Known internationally as the See: founder of modern nursing. https://www.natgeokids.com/u See: k/discover/history/general-hist ory/mary-seacole/ https://www.nationalarchives.go v.uk/education/resources/floren https://www.maryseacoletrust ce-nightingale/.org.uk/learn-about-mary/# Mothers of modern nursing FLORENCE MARY SECOLE NIGHTINGALE (1820- (1805-1881) 1910) ORIGINS OF LIFE DEBATE The origin of life debate Leeuwenhoek’s discovery (animalcule) reignited scientific debate on the origin of life: Spontaneous generation (revisited)- the hypothetical process by which living organisms develop from nonliving matter; appearance of maggots on decaying meat. However, by the 18th century it had become obvious that higher organisms could not be produced by nonliving material. The origin of life debate cont’d Francesco Redi 1626-1697 first to challenge notion of spontaneous generation – Maggots did not arise spontaneously from decaying meat (1668) – Demonstrated that maggots come from eggs of flies (Brittanica.com) Redi’s experiment 1. Redi took six jars 2. and divided in two groups of three: Flies could only enter the uncovered jar, and in this, maggots appeared. In the jar that was covered with gauze, maggots appeared on the gauze but did not survive. The origin of life debate cont’d John Needham (1713-1781) – Supporter of spontaneous generation – Refuted Redi’s claims with his chicken and corn broth experiment Broth found teeming with microbes after boiling and cooling – ?endospores – ?Air contamination – ?Not sterile experimental – ? Broth not boiled long enough to kill microbes The origin of life debate cont’d Lazzaro Spallanzini (1729- 1799) – Twenty years after Needham’s experiment postulated that microbes from the air may have entered the experiment. – Showed nutrient fluid sealed in a flask and heated showed no microbial growth The debate Spallanzani experiment Microbes move through air Microbes could be killed by boiling. The origin of life cont’d German scientist, Rudolf Virchow (1821- 1902)challenged spontaneous generation with biogenesis Biogenesis - living cells can arise only from pre-existing living cells Cells was the basic unit of the body that had to be studied to understand disease The origin of life cont’d Louis Pasteur: – Settled the spontaneous generation debate – Demonstrated presence of microbes in air and that they can act as contaminants – Microbes can be present in/on nonliving matter – Microbes can be destroyed by heat and other methods (basis of aseptic techniques) PASTEUR’S EXPERIMEN T The golden age of microbiology The period 1857-1914 Rapid advances in the sciences of microbiology Pasteur and Koch integral Significant discoveries during this period: – Agents of diseases – Role of immunity in disease prevention and cure The Golden age During this period scientists searched for answers to four questions 1. Is spontaneous generation of microbial life possible? 2. What causes fermentation? 3. What causes disease? 4. How can we prevent infection and disease? Koch’s Postulates 1. The microbe must always be present in every case of the disease 2. It must be isolated in pure culture on artificial media 3. When inoculated into healthy animal host it should produce the same disease 4. It must be isolated from the diseased animal again  KOCH’S POSTULATE Classification of micro-organisms Classification of microorganisms TYPES OF MICROORGANISMS Microorganisms are quite diverse – Prokaryotes( Bacteria & Archae ) – Eukaryotes (Protozoan & Fungi) – Viruses are acellular – Parasitic helminths are included in the study of microbiology as the infectious and diagnostic stages are microscopic Human pathogenic microorganisms Acellular/ subcellular infectious Viruses, Prions particles Prokaryotic microorganisms Bacteria Eukaryotic microorganisms Fungi, Protozoan Eukaryotic macroorganisms Helminths ( parasitic worms) Microbiology for nurses Classification of microorganisms Taxonomy- the science of the classification of living forms – To show degree of similarities between organism – Reference for identification of organisms Classification of Microorganisms Taxonomy Formal system originated by Carl von Linné (1707-1778) Identifying and classifying organisms according to specific criteria (visible) Each organism placed into a classification system – Plantae and Animalia See  https://www.youtube.com/watch ?v=Gb_IO-SzLgk  https://www.youtube.com/watch ?v=F38BmgPcZ_I Making the news Classification of microorganisms -Phylogeny Study of the evolutionary history of groups of organisms Achieved by molecular and morphologic studies Group common organisms together by juxtaposing similarities and differences All Species inventory: http://sciencenetlinks.com/science-news/science-updates/all-species-i nventory/ Evolution - living things change gradually over millions of years Changes favoring survival are retained and less beneficial changes are lost All new species originate from preexisting species Closely related organism have similar features because they evolved from common ancestral forms Evolution usually progresses toward greater complexity Taxonomy Domain Kingdom MNEMONIC Phylum Dear Class King Phillip Order Came Family Over For Genus Great species Soup 3 Domains Eubacteria true bacteria, peptidoglycan Archaea odd bacteria that live in extreme environments, high salt, heat, etc. (methanogens,extremophiles) Eukarya have a nucleus & organelles (humans, animals, plants)  Though diverse in morphology and organization, living organisms are generally classified into five kingdoms – Kingdom Monera== Bacteria & Archae (prokaryotes) – Protista==single celled eukaryotes – Fungi== a network of hypgae (eukaryotes) – Plantae== chlorophyl pigment & cell wall made of cellulose – Anamilia== lack cell wall, multicellular (eukaryotes) Five kingdom classification Taxonomy 4 main eukaryotic kingdoms: – Protista – Fungi – Plantae – Animalia  Scientific Nomenclature...Thanks to Carl Von Linne Binomial (scientific) nomenclature Gives each microbe 2 names: – Genus - noun, always capitalized – species - adjective, lowercase Scientific Nomenclature Organsism Nomenclature latinized each organism has unique two part genus species name: e.g. Escherichia coli written in italics or underlined genus with Capital first letter species/specific epithet all lowercase after first use in documents can abbreviate genus: E. coli name often describes organism: shape, habitat, name of discoverer, etc. Scientific Nomenclature Both italicized or underlined – Staphylococcus aureus (S. aureus) – Entamoeba coli (E. coli) – Escherichia coli (E. coli)  Full name must be noted before using abbreviated form e.g. Escherichia coli(E. coli)  Why is this important? Scientific Names Scientific Source of Source of Binomial Genus Specific Epithet Salmonella Honour Stupor in typhimurium Daniel Mice ( muri-) Salomon Streptococcus Chains of Forms pus pyogenes cells(strepto-) (pyo) Classification Systems in the Procaryotae Microscopic morphology- size, gram reaction (+/-) Macroscopic morphology – colony appearance no internal structure that are inclosed by membrane Physiological / biochemical characteristics Chemical analysis Serological analysis Genetic and molecular analysis Species and Subspecies 1. Species 1. collection of bacterial cells which share an overall similar pattern of traits in contrast to other bacteria whose pattern differs significantly 2. Strain or variety 1. culture derived from a single parent that differs in structure or metabolism from other cultures of that species. The slight distinction generally does not give rise to a new species but a strain 3. Type 1. subspecies that can show differences in antigenic makeup (serotype or serovar), susceptibility to bacterial viruses (phage type) and in pathogenicity (pathotype)  Bacterial Taxonomy Based on Bergey’s Manual Bergey’s Manual of Determinative Bacteriology – five volume resource covering all known procaryotes – classification based on genetic information – phylogenetic – two domains: Archaea and Bacteria – five volumes covering all known bacteria Major Taxonomic Groups of Bacteria Domain Archaea – primitive, adapted to extreme habitats(temperature, salinity) and modes of nutritional requirements(some require certain sulfurur compounds to grow Domain Bacteria Further division: – Gram-negative cell walls – mainly Gram-positive cell walls Archaea: The Other Procaryotes Archaea Have unique membrane lipids and cell wall construction Live in the most extreme habitats in nature, extremophiles Adapted to heat, salt, acid pH, pressure and atmosphere Includes: methane producers, hyperthermophiles, extreme halophiles, and sulfur reducers Eukaryotes classification Protista Fungi Plantae Animalia Algae  Fungal Classification Sexual reproduction – Spores are formed following fusion of male and female strains and formation of sexual structure Sexual spores and spore-forming structures are one basis for classification – Zygospores – Ascospores – Basidiospores Fungal Classification Subkingdom Amastigomycota – Terrestrial inhabitants including those of medical importance: 1. Zygomycota – zygospores; sporangiospores and some conidia 2. Ascomycota – ascospores; conidia 3. Basidiomycota – basidiospores; conidia 4. Deuteromycota – majority are yeasts and molds; no sexual spores known; conidia Protozoan Classification Difficult to classify because of diversity Simple grouping is based on method of motility, reproduction, and life cycle 1. Mastigophora – primarily flagellar motility, some flagellar and amoeboid 2. Sarcodina – primarily ameba; asexual by fission; most are free-living 3. Ciliophora – cilia; most are free-living, harmless 4. Apicomplexa – motility is absent except male gametes; sexual and asexual reproduction; complex life cycle – all parasitic Classification: Pathogenic vs Non Pathogenic Pathogenic organisms – Capable of causing disease Non-pathogenic organisms Classification of micro-organisms Classification according to Groups I. Bacteria: cocci, bacilli, spirilla and spirochetes – Ubiquitous single-celled organisms. – Small cells observable with the aid of a microscope. Bacterial microscopy  Schematic illustration of bacterial structure. Flagellum- organelle used for locomotion  Cellular structure of prokaryotic and eukaryotes cells cont’d Eukaryote Prokaryote  Cell wall - gives the cell its shape and retains the constituents Cell membrane-for filtering food and discharging waste products; semipermeable Nucleus -stores genetic material of the cell Cytoplasm - semiliquid substance which containing starch, fat and enzymes. Contents of a simple bacterial cell Classification: Viruses Small obligate intracellular parasites contain either a RNA or DNA genome surrounded by a protective, virus-coded protein coat A complete virus particle is called a virion May be enveloped or naked Viruses are grouped on the basis of size and shape, chemical composition and structure of the genome, and mode of replication. Types of viruses Micro-organisms as agents of infectious diseases Infections may be caused by: – bacteria, viruses, fungi, and parasites. Causative agents of infections may be: – Exogenous i.e. acquired from an external source – Endogenous i.e. acquired from normal flora Can you give examples of either types of infections? Portals of entry The portal of entry is the site at which a microbe enters the body Is dependent on how microbe travel from reservoir to the host Portals of entry include: – respiratory tract – gastrointestinal tract – genitourinary tract – Skin – mucous membranes. Mode of disease transmission There are various ways of disease transmission – Direct contact - Touching an infected host – Indirect contact - Touching a contaminated surface – Droplet contact - Coughing or sneezing – Faecal–oral route - consumption of faecal contaminated food or water – Airborne transmission - spores bearing pathogens e.g. fungi Mode of disease transmission cont’d Vector - Organism serves mechanical purpose by transmitting pathogens from one host to another but is unaffected by it Fomite - An inanimate object or substance capable of carrying infectious germs or parasites Environmental - Nosocomial infections Microbiology: its application Food & beverage industry – Bread, Cheese, Yoghurt – Wines, beers – Genetically modified foods Environmental science – Bioremediation-the process of using bacteria to chew up and detoxify the PCB pollutants. Biotechnology – GMOs, cloning Future trends Microbiology is required to face threat of new and reemerging human infectious disease & develop industrial technologies that are more efficient & environmentally friendly Future trends Production of new drugs & vaccines to counter the spread of multiple antibiotic resistance Further development of molecular techniques to facilitate study of microbes in their natural environment (microbial ecology) Vaccination==the impact of the www on vaccination policy etc  The knowledge of microbiology in the nursing profession is essential to the practice of medicine: A. Collection and transportation of specimen to the laboratory  Inappropriate/ Microbiolo inadequate/contaminated samples===impair analysis B. Interpretation of results received from the laboratory gy and  Must be au fait with the procedure for specimen analysis and conclusion nurses C. Prevention of hospital acquired infections  Have a good understanding of principles & procedures required to prevent HAI D. Waste disposal  Careful disposal & knowledge of microbiology paramount in keeping environs free of HAI