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A BEGINNING TO MEDICAL MICROBIOLOGYDr.T.V.Rao MDDr.T.V.Rao MD1

What is Microbiology?Microbes, or microorganisms are minute living things that are usually unable to be viewed with the naked eye.What are some examples of microbes?Bacteria, fungi, protozoa, algae, viruses are examples!Some are pathogenicMany are beneficial as Commensal bacteria

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Microbiology defined as the study of organisms too small to be seen with the naked eye. These organisms include viruses, bacteria, algae, fungi, and protozoa. Microbiologists are concerned with characteristics and functions such as morphology, cytology, physiology, ecology, taxonomy, genetics, and molecular biology. Defining Microbiology

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What is Microbiology

Study of different MicroorganismsCan be Bacteria Viruses Parasites Fungus

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Microbial World is FascinatingVirusesBacteria (Eubacteria) and ArchaeabacteriaFungi (Yeasts and Molds)ProtozoaMicroscopic Algae

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What are Microorganisms

Microbes are products of evolution, Consequence of Natural selection operating upon vast array of genetically diverse organismsDr.T.V.Rao MD6

History of Microbiology1673-1723, Antoni van Leeuwenhoek (Dutch) described live microorganisms that he observed in teeth scrapings, rain water, and peppercorn infusions.

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Scientific History of MicrobiologyThe Germ Theory of Disease1835: Agostino Bassi showed a silkworm disease was caused by a fungus.1865: Pasteur believed that another silkworm disease was caused by a protozoan.1840s: Ignaz Semmelweis advocated handwashing to prevent transmission of puerperal fever from one OB patient to another.Dr.T.V.Rao MD8

The Germ Theory of Disease1860s: Joseph Lister used a chemical disinfectant to prevent surgical wound infections after looking at Pasteurs work showing microbes are in the air, can spoil food, and cause animal diseases.

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Pioneers of MicrobiologyRobert Hooke, UK (1665)Proposed the Cell TheoryObserved cork with crude microscopeAll living things are composed of cellsSpontaneous generationSome forms of life could arise spontaneously from non-living matterFrancesco Redi, IT (1668)Redis experiments first to dispprove S.G.Dr.T.V.Rao MD10

Pioneers of MicrobiologyAntoni van Leeuwenhoek, DE (1673)First observed live microorganisms (animalcules)Schleiden and Schwann, DEFormulated Cell Theory: cells are the fundamental units of life and carry out all the basic functions of living thingsPasteur, FR and Tyndall, UK (1861)Finally disproved S.G.

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Pioneers of MicrobiologyLouis Pasteur (1822-1895), ChemistFermentation (1857)Pasteurization: heat liquid enough to kill spoilage bacteria (1864)Vaccine development rabies Proposed the germ theory of diseaseProposed aseptic techniques (prevent contamination by unwanted microbes)Director of Pasteur Institute, Paris (1894)Dr.T.V.Rao MD12

Pioneers of MicrobiologyJoseph Lister, UK (1867)Used phenol (carbolic acid) to disinfect woundsFirst aseptic technique in surgeryRobert Koch, DE (1876)Postulates Germ theory (1876)Identified microbes that caused anthrax (1876), tuberculosis (1882) and cholera (1883)Developed microbiological media & streak plates for pure culture (1881)Dr.T.V.Rao MD13

History of microbiology Anton van Leeuwenhoek (16321723): was the first microbiologist and the first person to observe bacteria using a single-lens microscope of his own design.

Louis Pasteur (18221895): Pasteur developed a process (today known as pasteurization) to kill microbes. pasteurization is accomplished by heating liquids to 63 to 65C for 30 minutes or to 73 to 75C for 15 seconds.

Robert Koch (18431910): was a pioneer in medical microbiology and worked in cholera, anthrax and tuberculosis. He was awarded a Nobel prize in 1905 (Koch's postulates) he set out criteria to test.

Alexander Fleming (1929): Discovered penicillin.

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Joseph Lister1860s: Joseph Lister used a chemical disinfectant to prevent surgical wound infections after looking at Pasteurs work showing microbes are in the air, can spoil food, and cause animal diseases.

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Learning Objectives To teach the basic immunological principlesImmunological methods for the study immunological disorders

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We all should be Familiar withGeneral MicrobiologyBacteriologyMycologyVirologyImmunologyParasitologyDr.T.V.Rao MD17

Microbes in Our LivesMicroorganisms are organisms that are too small to be seen with the unaided eye.Germ refers to a rapidly growing cell.

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Microbes make the Universe

There are > 5 x 1030 types Microbes in the worldHumans have intimate relation with Microbes > 90% of the cells in our Body are MicrobesDr.T.V.Rao MD19

Classification of MicroorganismsThree domainsBacteriaArchaeaEukaryaProtistsFungiPlantsAnimals

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Naming and Classifying Microorganisms

Carolus Linnaeus (1735) established the system of scientific nomenclature.Each organism has two names: the genus and specific epithet.Are italicized or underlined. The genus is capitalized and the specific epithet is lower case.

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Edward Jenner Vaccinating aChild

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Louis Pasteur1922 - 1995Contributed best in MicrobiologySterilizationHot Air ovenAutoclaveAnthrax vaccineRabies vaccineBuilt the Pasteur Institute

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Louis Pasteur

Vacca Cow cow pox virus are given for the prevention of Small Pox Louis Pasteur considered the father of Modern MicrobiologyPasteur coined the word Vaccine

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Robert Koch1843 - 1910A German scientistFormulated the Bacteriological techniquesStaining MethodsDiscovered the Mycobacterium and Vibrio cholera

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Koch's Postulates1.Microorganisms are isolated from dead animals

2.Microorganisms are grown in pure culture

2b.Microorganisms are identified

3.Microorganisms are injected into healthy animals

4.Disease is reproduced in second animal

5.Microorganisms are grown in pure culture

5b.Identification of identical microorganism.Dr.T.V.Rao MD26

Kochs Postulates

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Figure 14.3, steps 12Dr.T.V.Rao MD28

Figure 14.3, steps 34Dr.T.V.Rao MD29

Figure 14.3, step 5Dr.T.V.Rao MD30

Exceptions to Kochs PostulatesMicroorganisms that are unable to be cultured on artificial media (example: Treponema pallidum) More organism work in synergy to cause a disease.Symptoms and diseases can be causes by any one of several microbes.

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Biological Principles illustrated by MicrobiologyDr.T.V.Rao MD32

MicroorganismsNon-cellular organismProkaryotesEukaryotesOthersPrionsViroidFungiBacteriumVirus

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Organisms included in the study of Microbiology1. Bacteria2. Protozoans3. Algae4. Parasites5. Yeasts and MoldsFungi6. VirusesBacteriologyProtozoologyPhycologyParasitology

MycologyVirologyDr.T.V.Rao MD34

How to Study Medical Microbiology?Dr.T.V.Rao MD35Fundamentals of MicrobiologyBacteriologyVirologyMycologyBiological PropertiesMorphology, identification, Antigenic structurePathogenesis and PathologyClinical findingsDiagnostic Laboratory TestsImmunityTreatment & PreventionEpidemiology & Control

Basic Classification of MicroorganismEukaryotes Large in size Mitochondria Present Membrane bound Nucleus Eg Algae Protozoa Fungi Slime Moulds Contains all enzymes for production of metabolic energy Prokaryotes Small in Size DNA not separated from cytoplasm Mitochondria absent

Eg Bacteria

Contains all enzymes like EukaryotesDr.T.V.Rao MD36

Prokaryotic Cell Structure Prokaryotic cells are about 10 times smaller than eukaryotic cells. A typical Escherichia coli cell is about 1 m wide and 2 to 3 m long. Structurally, prokaryotes are very simple cells when compared with eukaryotic cells, and yet they are able to perform the necessary processes of life. Reproduction of prokaryotic cells is by binary fission, the simple division of one cell into two cells, after DNA replication and the formation of a separating membrane and cell wall. Dr.T.V.Rao MD37

Bacteria

ProkaryotesPeptidoglycan cell wallsBinary fissionFor energy, use organic chemicals, inorganic chemicals, or photosynthesis

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Bacterial Cell Wall The structure of bacterial cell walls is quite different from the relatively simple structure of eukaryotic cell walls, although they serve the same functions, providing rigidity, strength, and protection. The main constituent of most bacterial cell walls is a complex macromolecular polymer known as peptidoglycan (murein), consisting of many polysaccharide chains linked together by small peptide (protein) chains. Peptidoglycan is only found in bacteria. The thickness of the cell wall and its exact composition vary with the species of bacteria. The cell walls of Gram-positive bacteria have a thick layer of peptidoglycan combined with teichoic acid and lipoteichoic acid molecules. The cell walls of Gram-negative bacteria have a much thinner layer of peptidoglycan, but this layer is covered with a complex layer of lipid macromolecules, usually referred to as bacteria capsule.Dr.T.V.Rao MD39

Figure 1-9: Gram Stain Dr.T.V.Rao MD40

Figure 3-1. Various forms of bacteria, including single cocci, diplococci, tetrads, octads, streptococci, staphylococci, single bacilli, diplobacilli, streptobacilli, branching bacilli, loosely coiled spirochetes, and tightly coiled spirochetes.Dr.T.V.Rao MD41

Capsule stain. The capsule stain is an example of a negative staining technique. The bacterial cells and the background stain, but the capsules do not. The capsules are seen as unstained halos around the bacterial cells.Dr.T.V.Rao MD42

. Flagellar arrangement. The four basic types of flagellar arrangement on bacteria: peritrichous, flagella all over the surface; lophotrichous, a tuft of flagella at one end; amphitrichous, one or more flagella at each end; monotrichous, one flagellum.Dr.T.V.Rao MD43

Binary fission. Note that DNA replication must occur before the actual splitting (fission) of the parent cell.Dr.T.V.Rao MD44

Pathogenic ProkaryotesMycoplasmaBacteriaSpirochetesRickettsiaChlamydiaeActinomycesDr.T.V.Rao MD45

VirusesViruses lack many of the attributes of cells, including the ability to replicate. Only when it infects a cell does a virus acquire the key attribute of a living system: reproductionA viral particle consists of a nucleic acid molecule, either DNA or RNA, enclosed in a protein coat, or capsid

Viruses are known to infect all cells, including microbial cells. Host-virus interactions tend to be highly specificDr.T.V.Rao MD46

Discovery of VirusIwanovskia Russian chemist, 1892Tobacco Mosaic DiseaseBeijerinck confirmedWalter Reed, USAYellow fever virusIst human virusDr.T.V.Rao MD47

Tobacco mosaic disease, caused by the tobacco mosaic virus

Viruses

A virus is not a cell!Viruses are replicated only when they are in a living host cellConsist of DNA or RNA coreCore is surrounded by a protein coatCoat may be enclosed in a lipid envelope

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What are Viruses

Viruses Dependent on Host cells for necessary functions and MultiplicationIntracellular parasitesContain either DNA or RNA never both.

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PrionA kind of infectious protein that can resist the digestion of proteinaseThe cellular form of the prion protein (PrPc) is encoded by the hosts chromosomal DNAAn abnormal isoform of this protein (PrPres) is the only known component of the prion and is associated with transmissibility. Kuru, Creutzfeldt-Jakob disease (CJD), Gerstmann-Strussler-Scheinker disease, fatal familial insomnia, and Bovine spongiform encephalopathy (BSE)Dr.T.V.Rao MD50

ViroidSmall, single-stranded, covalently closed circular RNA molecules existing as highly base-pairedrod-like structures; they do not possess capsidsThey range in size from 246 to 375 nucleotides in length. The extracellular form of the viroid is naked RNAthere is no capsid of any kindThe RNA molecule contains no protein-encoding genes, and the viroid is therefore totally dependent on host functions for its replicationThe RNAs of viroids have been shown to containinverted repeated base sequences at their 3' and 5' ends, a characteristic of transposable elements and retroviruses. Thus, it is likely that they have evolvedfrom transposable elements or retroviruses by the deletion of internal sequencesDr.T.V.Rao MD51

1928: Alexander Fleming discovered the first antibiotic.He observed that Penicillium fungus made an antibiotic, penicillin, that killed S. aureus.1940s: Penicillin was tested clinically and mass produced.

Scientific era of Antibiotics

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Discovery of AntibioticsAlexander Fleming (1881-1955)

Sir Alexander Fleming Ernst Boris Chain Sir Howard Walter FloreyDr.T.V.Rao MD53

Microbes are used to produce Antibiotics Penicillin

PenicillinMold Pencillium notatum1928 Alexander FlemingDr.T.V.Rao MD54

How to Study Medical Microbiology?Dr.T.V.Rao MD55Fundamentals of MicrobiologyBacteriologyVirologyMycologyBiological PropertiesMorphology, identification, Antigenic structurePathogenesis and PathologyClinical findingsDiagnostic Laboratory TestsImmunityTreatment & PreventionEpidemiology & Control

Bacteria - what comes to mind?DiseasesInfectionsEpidemicsFood SpoilageOnly 1% of all known bacteria cause human diseasesAbout 4% of all known bacteria cause plant diseases95% of known bacteria are non-pathogensDr.T.V.Rao MD56

Staphylococcus aureusStaphylococcus epidermidisStreptococcus pneumoniaVibrio choleraRhodospirillium rubrumBacillus subtilisMicrococcus luteus

Escherichia coliBacillus anthrasisSalmonella enteridisStreptococcus pyogenesSteptococcus lactisStreptococcus faecalisErlichia canisCampylobacter jujuniHelicobacter pyloriEnterobacter aerogenesDr.T.V.Rao MD57

Microbes Benefit Humans1.Bacteria are primary decomposers - recycle nutrients back into the environment (sewage treatment plants)2. Microbes produce various food products cheese, pickles, sauerkraut, green olivesyogurt, soy sauce, vinegar, breadBeer, Wine, AlcoholDr.T.V.Rao MD58

Microbes are also capable of causing many diseasesPneumoniaWhooping CoughBotulism Typhoid Fever MeaslesCholeraScarlet Fever MumpsSyphilisGonorrhea Herpes 1Chlamydia Tuberculosis Herpes 2Meningitis Tetanus RMSVStrep Throat Lyme Disease AIDSBlack PlagueDiarrhea GangreneDr.T.V.Rao MD59

Progress of Hepatitis Viruses1947, concepts of hepatitis A and serum-transmitted hepatitis1970, Dane particle was observed (hepatitis B virus)1973, hepatitis A virus1978, non-A, non-B hepatitis viruses (NANBV)1989, hepatitis C virus (HCV), hepatitis E virus (HEV)1990-1994, non A-E hepatitis viruses1995, hepatitis G virus (HGV)1997, TT virus (TTV)Dr.T.V.Rao MD60

Human Immunodeficiency Virus & AIDS1981, the first cases report about AIDS1983, HIV was isolated1990s, HAART (cocktail therapy) was employedSo far, no effective vaccine availableDr.T.V.Rao MD61

HIV AIDS

Luc Montaigner and Robert Gallo announce their discovery of the immunodeficiency virus (HIV) believed to cause AIDS. (American Society for Microbiology Archives)Dr.T.V.Rao MD62

ParasitologyParasitology is the study of parasites .and their interactions with their hosts. The science of parasitology has a long history and has its roots in zoology, with its emphasis on the identification and classification of parasites and of life cycles,

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Taxonomic classification of parasitic organismsThe classification of parasites is controversial - there is no universally accepted systemParasites form part of the animal kingdom which comprises some 800,000 identified species categorised into 33 phyla (but it is estimated that there may be ~10m species in total)The parasitic organisms that are of importance for human health are eukaryotes - they have a well defined chromosome in a nuclear membrane (as opposed to prokaryotes which have no nuclear membrane, e.g. bacteria)Dr.T.V.Rao MD64

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What Are Fungi

Considerable variation in size.Internal Molecular systemWell defined cell wall composed of polysaccharidesGaining importance in Immunosupressed patients and increased use of Antibiotics

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Zoonotic Diseases

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How Humans Respond to InfectionsStudy of Immunology

In spite of Infection we survive with our ability to protect with a system inherent in our BodyCalled the Immune response comprises the Medical Immunology

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Modern Developments in MicrobiologyImmunology is the study of immunity. Vaccines and interferons are being investigated to prevent and cure viral diseases.The use of immunology to identify some bacteria according to serotypes (variants within a species) was proposed by Rebecca Lancefield in 1933.

Figure 1.4 (3 of 3)Dr.T.V.Rao MD68

PathogenesisImmunity

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Why we should learn Medical Microbiology

We study the Microbes which infects and causes DiseasesWe study their Diagnosis Prevention Treatment

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Modern Developments in MicrobiologyImmunology is the study of immunity. Vaccines and interferons are being investigated to prevent and cure viral diseases.The use of immunology to identify some bacteria according to serotypes (variants within a species) was proposed by Rebecca Lancefield in 1933.

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Must learn

Natural History of the DiseaseEtiologyPathogenesisLaboratory DiagnosisTreatment and Control and PreventionDr.T.V.Rao MD72

We must be familiar with Knowledge On .

Names of the MicrobesNames of the diseasesMode of transmissionPathogenic MicrobesCommensal OrganismsIdentify wether Bacteria, Virus, Parasite or FungiTreating and Preventing

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The Birth of Modern ChemotherapyTreatment with chemicals is chemotherapy.Chemotherapeutic agents used to treat infectious disease can be synthetic drugs or antibiotics.Antibiotics are chemicals produced by bacteria and fungi that inhibit or kill other microbes.Quinine from tree bark was long used to treat malaria.1910: Paul Ehrlich developed a synthetic arsenic drug, salvarsan, to treat syphilis.1930s: Sulfonamides were synthesized.Dr.T.V.Rao MD74

Commonly Used AntibioticsPenicillinCephalosporins,Tetracycline's QuinolonesVancomycinChloramphenicolDrugs for Tuberculosis eg StreptomycinDr.T.V.Rao MD75

Vaccines Produce Immunityand Prevents Several Infections

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Commonly used VaccinesSmall pox eradicatedBCG,MMRPolio oral VaccineTriple AntigenHepatitis B Vaccine

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Course objectivesTo provide the student with the basic knowledge of micro-organisms in generalTo study the main characteristics of Microbes of medical importanceTo teach aseptic techniquesTo provide an understanding of antimicrobial agents Dr.T.V.Rao MD78

What Skills You should Develop

Able to identify the Infective ConditionsTimely DiagnosisChoosing appropriate testsSelection of AntibioticsImplement measures to prevent diseases in patients and Society

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Protect Yourself from Infections

Certain infections can infect youEg HIV, Hepatitis B infections,Tuberculosis,Many respiratory infections

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Working In the Hospital

Hospitals are not safe Follow Universal precaution protect yourself as our patients can be source of Infection if you don't handle the matters with scientific knowledge.

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Medical Microbiology advanced Beyond our ImaginationCan we handle it ???

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Major Selected Nobel Prizes in Physiology or Medicine* The first Nobel Prize in Physiology or Medicine.Dr.T.V.Rao MD831901* von BehringDiphtheria antitoxin1902RossMalaria transmission1905KochTB bacterium1908MetchnikoffPhagocytes1945Fleming, Chain, FloreyPenicillin1952WaksmanStreptomycin1969Delbrck, Hershey, LuriaViral replication1987TonegawaAntibody genetics1997PrusinerPrions

Students requirement for the courseTimetable Literature books, etc Practical manualLaboratory coatAttendance and active participationSeek advice timelyDr.T.V.Rao MD84

The Programme Created by Dr.T.V.Rao MD for medical and paramedical Students in the Developing World Emaildoctortvrao@gmail.com Dr.T.V.Rao MD85