Introduction To Bacteriology PDF Handout

8/12/2024 ...

8/12/2024  4 GROUPS OF MICROBES ▪ Viruses Very simple microbes, BACTERIOLOGY consisting of nucleic acid, a few proteins,  and (in some) a lipid envelope ▪ Fungi Prepared by: Giane Paola T. Tanjuaquio, RMT heterotrophic eukaryotes that obtain nutrients through absorption.   WHAT IS MICROBIOLOGY? ▪ Parasites Eukaryotic organisms that live at the expense of their ▪ includes the study of certain nonliving entities as hosts exist as unicellular well as certain living organisms. Collectively, organisms of microscopic these nonliving entities and living organisms are size whereas others are called microbes. multicellular organisms. ▪ Bacteria ▪ A branch of biology which deals with the study of living organisms that are too small to be seen Are prokaryotic, unicellular by the naked ey organisms that lack a nuclear membrane and true nucleus.  BRANCHES OF MICROBIOLOGY  DEFINITION OF TERMS ▪ Pathogens: Disease causing microorganisms such as bacteria, fungi, protozoans and viruses ❖ Types of Pathogens a. True Pathogen: Refers to an organism that will cause disease in a healthy host b. Opportunistic Pathogens: Refers to organisms that will cause disease in an immunocompromised host ▪ Pathogenicity: Refers to the ability of an organism to cause disease in a host organism 1  8/12/2024   ▪ Disease: An altered health state in an infected host ▪ Virulence ▪ Infectious Disease: Is an illness caused by a pathogen which invades Refers to the degree of pathogenicity; the power by which body tissues and causes damage a pathogen can cause severe disease ▪ Communicable Disease: Is an infectious disease that is capable of ▪ Pathogenic Determinants/ Virulence Factors spreading from person to person Refers to any genetic, biochemical or structural features that ▪ Symptoms: Refers to any subjective evidence of disease. These are enable a pathogen to cause disease in a host organism usually perception of the patient having the disease such as ▪ Infection headache, dizziness, etc. Refers to the entry, invasion and multiplication of pathogens in or ▪ Signs: Refers to readily observable evidence of disease. These are on to the host body system which results to subsequent tissue injury usually physical manifestation of the disease such as rashes, and progress to overt disease bleeding etc.   TYPES OF INFECTION A. Based on Source of Pathogen ▪ Normal Flora: Bacteria that are in or on different sites of the Endogenous Infection: Infection arising from colonizing flora body that usually do not harm the host unless the host defense is compromised Exogenous Infection: Infection arising from invading pathogen from the external environment ▪ Colonization: Refers to the establishment of substantial number of microorganisms usually in the skin or mucosa B. Based on Clinical Onset of Signs and Symptoms but there’s no penetration of tissues Acute Infection: Rapid/ sudden onset of signs and symptoms which are usually severe to fatal that may lead to death Chronic Infection: Gradual onset of signs and symptoms that are usually mild to moderate that may progress to long standing infection   C. Based on Etiologic/ Causative Agent Earliest Known Infectious Diseases Nosocomial Infection: Infection acquired during hospitalization ▪ 3180 BC Pestilence and Plague Zoonotic Infection (Zoonosis): Is an animal disease which can ✓ Fatal epidemic disease caused by a bacteria called Yersinia spread to humans; animal acquired infection pestis – Black Death D. Based on Clinical Manifestation Represent the first recorded epidemic Subclinical/ Asymptomatic/ Nonapparent: No obvious appearance of ▪ Around 1900 BC Bubonic Plague signs and symptoms and the person is unaware of the infection ✓ near the end of the Trojan war, the Greek army was decimated Clinical/ Symptomatic/ Apparent: Associated with presence of by this epidemic overt signs and symptoms of the disease ▪ 1500 BC Ebers papyrus ✓ describing epidemic fevers 2  8/12/2024   Anton van Leeuwenhoek (1632–1723) ▪ 1122 BC Smallpox ▪ First person to see live bacteria and protozoa ✓ occurred in China ▪ “Father of Microbiology, Bacteriology, ▪ 790, 710, and 640 BC Epidemics of plague Protozoology” ✓ occurred in Rome and in Greece around 430 BC ▪ He ground tiny glass lenses, which he mounted in ▪ There are early accounts of rabies, anthrax, dysentery, smallpox, small metal frames, thus creating what today ergotism, botulism, measles, typhoid fever, typhus fever, diphtheria, are known as single-lens microscopes or simple microscopes and syphilis ▪ He observed various tiny living creatures, which he called “animalcules” (bacteria and protozoa)   ▪ Syphilis (Treponema pallidum) Louis Pasteur (1822–1895) ✓ First appearance in Europe in 1493 ✓ Was carried to Europe by Native Americans who were ▪ Demonstrated that different types of brought to Portugal by Christopher Columbus microbes produce different fermentation products ✓ Neapolitan Disease (French) ✓ French or Spanish Disease (Italian) ▪ Disproved theory of spontaneous generation/ Abiogenesis ✓ French pox (English) Life can arise spontaneously from ✓ Spanish, German, Polish and Turkish pocks non-living materials ✓ The infection was named “Syphilis” in 1530 ▪ He introduced the terms “aerobes” (requires oxygen) and “anaerobes” (does not requires oxygen)   ▪ Pasteurization Heating liquids to 63 – 65’C for 30 minutes or 73 – 75’C for 15 seconds PIONEERS IN MICROBIOLOGY Type of sterilization. Only kills pathogens ▪ Germ Theory of Disease Specific microbes cause specific infectious diseases Developed vaccines to prevent chicken cholera, anthrax and swine erysipelas 3  8/12/2024   The Development of Aseptic Techniques Robert Koch (1843–1910) ▪ Dr. Oliver Wendell Holmes ▪ Made many significant contributions to the observed that mothers who gave birth at home experienced fewer germ theory of disease infections than did mothers who gave birth in the hospital ▪ Discovered that B. anthracis produces spores, ▪ Dr. Ignaz Semmelweis capable of resisting adverse conditions Father of Hand Hygiene ▪ Developed methods of fixing, staining, and showed quite clearly that women became infected in the photographing bacteria, methods of cultivating maternity ward after examinations by physicians coming directly from bacteria on solid media the autopsy room ▪ Discovered the bacterium (M. tuberculosis) that ▪ Joseph Lister causes tuberculosis and the bacterium (Vibrio cholerae) that causes cholera first to introduce aseptic techniques aimed at reducing microbes in a medical setting and preventing wound infections PERIOD KEY SCIENTIST/S DEVELOPMENTAL NOTES  1665 Robert Hooke Publication of the first description of microbes Koch’s Postulates 1667 Anton van Leeuwenhoek Observation of “little animals” 1796 Edward Jenner Smallpox Vaccination – first scientific validation Advocating handwashing in the prevention of 1850 Ignaz Semmelweis the spread of disease 1861 Louis Pasteur Spontaneous generation disproved Publication of the paper supporting the germ 1862 Louis Pasteur theory of disease 1867 Joseph Lister Practice of Antiseptic Surgery Discovery of Bacillus anthracis which became the 1876 Robert Koch first proof of germ theory Utilization of solid culture media for bacterial 1881 Robert Koch growth 1882 Robert Koch Outlined Koch’s postulate Paul Erlich Development of Acid-fast stain 1884 Hans Christian Gram Gram stain developed PERIOD KEY SCIENTIST/S DEVELOPMENTAL NOTES  The Discovery of Spores and 1885 Louis Pasteur First Rabies Vaccination Sterilization 1887 Richard J. Petri Invention of the Petri Dish 1892 Dmitri losifovich Ivanovski Discovery of Viruses ▪ John Tyndall 1893 T. Smith and F.I. Kilbourne Zoonosis – first described Provided the initial evidence that some of the microbes in dust and air Viral dependence on living host cells for 1899 Martinus Beijerinck reproduction recognized have very high heat resistance and that particularly vigorous Proof the mosquitoes carry the agent of yellow treatment is required to destroy them. 1900 Walter Reed fever Developed Tyndallization 1910 Paul Erlich Discovered the cure for syphilis 1928 Alexander Fleming Discovery of Penicillin ▪ Ferdinand Cohn 1953 J. Watson and F. Crick Proposed and built the DNA model Clarified the reason that heat would sometimes fail to completely 1977 W. Gilbert, F. Sanger Development of the DNA sequencing method eliminate all microorganisms Kary Mulis Invention of the Polymerase Chain Reaction “Sterile” was established (PCR) 4  8/12/2024   Classification ▪ Carl von Linné (Linnaeus; 1701–1778) Naming, Classifying and Identifying ▪ a Swedish botanist Microorganism ▪ laid down the basic rules for classification and established taxonomic categories, or taxa   Carl Von Linne’s Classification System TAXONOMY Greek taxes: arrangement; Greek nomos: law is the orderly classification and grouping of organisms into taxa (categories). It is based on similarities and differences in genotype and phenotype 1. Genotype: genetic makeup of an organism, or combinations of forms of one or a few genes under scrutiny in an organism's genome. 2. Phenotype: readily observable physical and functional features of an organism expressed by its genotype.   Three Categories of Taxonomy ▪ Nomenclature ▪ Robert Whittaker is the assignment of scientific names to the various taxonomic categories Whittaker’s tree and individual organisms based on structural similarities and ▪ Classification differences, such as prokaryotic and Attempts the orderly arrangement of organisms into a hierarchy of taxa eukaryotic cellular organization, and the (categories) way these organisms obtained their ▪ Identification nutrition. Is the process of discovering and recording the traits or organisms so that they may be recognized or named and placed in overall taxonomic scheme (genotypic and phenotypic characteristics) 5  8/12/2024   Nomenclature Whittaker Tree ▪ International Code of Nomenclature of Bacteria (ICNB) or the Bacteriological Code (BC) provides the accepted labels by which organisms are universally recognized ▪ Binomial system of nomenclature every organism is assigned a genus and a species of Latin or Greek derivation Each organism has a scientific “label” consisting of two parts: o Genus – the first letter is always capitalized o Species – first letter is always lower case o Printed in italics or underlined in script (separate line for genus and species)   Standard rules for denoting bacterial names ▪ Carl R. Woese devised a Three-Domain System of ▪ Family name is capitalized and has an "-aceae" ending (Micrococcaeceae) Classification ▪ Genus name is capitalized and followed by the species epithet, which begins there are two domains of with a lowercase letter, both the genus and the species should be italicized in print but underlined when written in script (eg. Staphylococcus aureus or procaryotes – base on cellular Staphylococcus aureus) organization and function (Archaea and Bacteria) and one ▪ Abbreviated by using the first letter (capitalized) of the genus followed by a domain (Eucarya or Eukarya), period and the species epithet (S. aureus). which includes all eucaryotic ▪ First two letters or the first syllable are used when two or more genera names organisms. begin with the same first letter (Staph. And Strept. For Staphylococcus and Streptococcus) ▪ Escherichia coli (E. coli or Esch. coli) is a bacterium, but Entamoeba coli (Ent. coll) is an intestinal parasite   Three-Domain System of Classification Identification ▪ Genotypic characteristics relate to an organism’s genetic makeup, including the nature of the organism’s genes and constituent nucleic acids ▪ Phenotypic characteristics are based on features beyond the genetic level and include both readily observable characteristics and characteristics that may require extensive analytic procedures to be detecte 6  8/12/2024   GENOME CHARACTERISTIC PROKARYOTE EUKARYOTE ▪ Subspecies - based on phenotypic differences (abbreviated "subsp.") ❑ Location In the nucleoid, at the In the nucleus ▪ Serovarieties - based on serologic differences (antigenic properties) mesosome (abbreviated "serovar") ❑ Chromosomal DNA Circular; complexed with Linear; complexed with ▪ Biovarieties - based on biochemical or physiological test result RNA basic histones and other proteins differences (abbreviated "biovar") ❑ Extrachromosomal Plasmids, small circular circular DNA molecule of DNA containing In mitochondria and ▪ Phage typing - based on susceptibility to specific bacterial phages accessory information; most chloroplasts ▪ Analysis of ribosomal RNA (rRNA) commonly found in gram- negative bacteria; each carries genes for its own replication; can confer resistance to antibiotics CHARACTERISTIC PROKARYOTE EUKARYOTE  By Cellular Type ❑ Reproduction Asexual (binary fission) Sexual and asexual ❑ Membrane-bound Absent All ▪ Prokaryotes ▪ Eukaryotes Organelles Gr. “before kernel” (nucleus) Gr. eu: “well or good” and Gr. ❑Golgi Bodies Absent in all Present in some Karyon: kernel domains Archaea and Bacteria(Eubacteria) fungi, algae, protozoa, ❑Lysosomes Absent in all Present in some; contain o Simple cells that lacking animals, and plants hydrolytic enzymes membrane-bound nucleus o With membrane-bound nucleus ❑ Endoplasmic Absent in all Present in all; lipid o Prokaryotes fall under the Reticulum synthesis, transport domain Archaea and o Categorized under the Bacteria. Bacteria fall in domain Eukarya ❑ Mitochondria Absent in all Present in most either of these two domains CHARACTERISTIC PROKARYOTE EUKARYOTE  COMPARISON OF PROKARYOTIC AND ❑ Nucleus Absent in all Present in all EUKARYOTIC CELL ORGANIZATION ❑ Chloroplasts for Absent in all Present in algae and plants photosynthesis Present in all ❑ Ribosomes: site of Present in all CHARACTERISTIC PROKARYOTE EUKARYOTE protein synthesis (nonmembranous) Size 70S consisting of 50S and Size 80S consisting of 60S ❑Typical Size 0.4-2 um in diameter 10-100um in diameter 30S subunits and 40S subunits 0.5-5 um in length >10 um in length ❑ Electron Transport for In the cell membrane; no In the inner membrane of ❑ Nucleus No nuclear membrane, Membrane-bound energy mitochondria present mitochondria and nucleoid region of the nucleus chloroplasts cytosol ❑ Sterols in cytoplasmic Absent except in Present membrane Mycoplamatacaeae 7  8/12/2024 CHARACTERISTIC PROKARYOTE EUKARYOTE  ❑ Plasma membrane Lacks carbohydrates Also contains glycolipids and glycoproteins ▪ Extremophiles ❑ Cell wall, if present Peptidoglycan in most Cellulose, phenolic lovers of the extreme conditions bacteria polymers, lignin (plant), E.g. Sulfurovum epsilonproteobacteria chitin (fungi), other glycans (algae) ❑ Glycocalyx Present in most as an Present; some animal cells ▪ Halophiles organized capsule or salt-loving cells unorganized slime layer in Utah's Great Salt Lake Found in ❑ Cilia Absent Present environments high in salinity or salt concentrations ❑ Flagella, if present Simple flagella Complex cilia or flagella E.g. Salinibacter ruber ❑ Pili and Fimbriae Present Absent  ▪ Thermophiles heat-loving cells in hot springs and deep ocean vents. Thrive in environments with extreme heat. E.g. Bacillus stearothermophilus ▪ Anaerobic methanogens give off swamp gas and inhabit the intestinal tracts of animals. E.g. Methanobacterium wolfei  ▪ Archaea (Archaeobacteria) more closely related to eukaryotic cells / found in microorganisms that grow under extreme environmental peptidoglycan conditions/lack o Greek: (archaics) ancient, origin from the earliest cells o Those that belong in the domain Archaea are some of the most resistant organisms are they are found in extreme environmental conditions. o Has cell wall, plasma membrane, ribosomes and flagella (no nucleus and membrane-bound organelles o Never contain peptidoglycan contain protein or glycoprotein wall structure known as S-layer 8