3Course Introduction Instructor: Dr Elena Romancenco Department of Microbiology, Virology and ImmunologyWEBSITE:
4Course objectivesList major groups of microorganisms and their habitats.Overview and history of Microbiology.Describe the system of scientific nomenclature used to name microorganisms.
5DefinitionMicrobiology (mikros bios logos – small, live, study) study microorganisms and their activities.Microbiology is the study of microorganisms usually less than 1mm in diameter which requires some form of magnification to be seen clearly.Microbiology - study the organisms that can exist as single cells, contain a nucleic acid genome for at least some part of their life cycle, and are capable of replicating that genome themselves or getting replicated with the help of host cells
6Branches of Microbiology Bacteriology: study of bacteriaMycology: study of fungiVirology: study of virusesBeijerinck, NE: discovered intracellular reproduction of TMV; coined the term “virus” (1899)Parasitology: study of protozoa and parasitic worms
7Branches of Microbiology Immunology: study of immunityEdward Jenner, UK: developed vaccination (1798)Metchnikoff, RU: discovered phagocytes (1884)Paul Ehrlich, DE: theory of immunity (1890)ChemotherapyTreatment of disease by using chemical meansAntibiotics produced naturallySynthetic drugsPaul Ehrlich (1878) – used arsenic compounds to fight disease
8Branches of Microbiology ChemotherapyAlexander Fleming, Scotland (1928) discovered penicillinSelman Waksman, Ukraine (1944) discovered streptomycinProblemsToxicity of drugs => Selective toxicityResistance of bacteria to drugs
9Affect our lives in many different ways. Microorganisms are everywhere, but why is so important to learn about them?Affect our lives in many different ways.
10Microbes are capable of growing in a wide variety of environments. Bacteria will grow in frigid glaciers to boiling volcanic springs, dry sands to the open ocean.
12IMPORTANCE OF MICROORGANISMS Microorganisms are the oldest forms of life.Nutrient production & energy flowProduction of foodsDecomposition (bioremediation)Without certain microorganism life could not exist; produce O2 and N2Production of drugs & vaccinesGenetic engineeringCausing diseaseMicroorganisms have killed more people than have ever been killed in war.
13Why Study Medical Microbiology? The majority of serious diseases in humans (especially those of early childhood) are due to microbial infections.Prior to the discovery of antibiotics and vaccines, a large proportion of children died before adulthood because of infectious disease.Till 1900, the average life expectancy in the United States was 40 years of age.In years, largely due to the near eradication of most serious early childhood diseases.This trend is seen in the gap between developed and developing countries in terms of causes of death (mortality).
14MICROBESMICROBES includes all those living organisms that can not be viewed (seen) in any detail by the human eye.Alternatively, a MICROBE is any living creature that must be examined with a magnifying lens in order to see its unique physical characteristics (size, shape, motility, color).
15Microbes Pathogen or pathogenic - capable of producing disease. Though only a minority of microorganisms are pathogenic, practical knowledge of microbes is necessary for their treatment so is highly relevant to medicine and related health sciences.Normal flora [normal microbiota] - not typically-disease-causingmicroorganisms normally found in and on healthy individuals.on the skin,in the eyes,in the nose,in the mouth,in the upper throat,in the lower urethra,in the lower intestine.
16the Bacterium Escherichia coli; a photosynthetic cyanobacteriuma fungusEbola virusthe malaria parasite (a protozoan16
17A, Influenza virus;B, West Nile Virus;C, Staphylococcus aureus;D, Streptococcus pneumoniae.
18Microbiologists may be interested in various characteristics or activities of microbs and may study: Microbial morphologyMicrobial cytologyMicrobial physiologyMicrobial ecologyMicrobial genetics and molecular biologyMicrobial taxonomy
20For many years, living organisms were divided into two kingdoms: Animalia (animal) andPlantae (vegetable).
21Classification Schemes Two kingdomsPlantaePlantaeAnimalia
22But after 1800s, scientists realized that these two kingdoms could not adequately express the diversity of life.Since the 1960s, the most widely used scheme - five kingdoms.Viruses are separate group of biological entities, although not organisms in the same sense as Eukaryotes, Archaea and Bacteria.
24Classification of Life 3 major Domains of lifeBacteriaArchaeaEukaryota (Eukarya)The first two are Prokaryotes (Bacteria and Archaea)- without true nucleus, while the Eukaryotes all have a true nucleus in each cell.The 3 Domains. Source:
26Kingdom Monera All organisms in the Kingdom Monera are prokaryotes. lack nuclei and organellesmost of their cell walls are made of peptidoglycan (the exceptions are the archaebacteria).The archaebacteria have cell walls that lack peptidoglycan, cell membranes that utilize different lipids, and ribosomes similar to those found in eukaryotes.The bacteria (eubacteria-true bacteria) are characterized by how they metabolize resources, their means of motility, and their shape.Most organisms in the Kingdom Monera reproduce through binary fission (asexual) or conjugation (sexual).
27Bacteria Most utilize flagella for movement. Digestion is extracellular (outside the cell) and nutrients are absorbed into the cell.Circulation and digestion in Kingdom Monera is accomplished through diffusion.
29According the metabolism Autotrophs manufacture their own organic compounds.Heterotrophs obtain their energy by feeding on other organic substances.Saprophytes, a special kind of heterotroph, obtain energy by feeding on decaying matter.
30According the symbiotic relationships with other organisms: In parasitism, harm is caused to the host.In commensalism, one organism benefits while the other is unaffected.In mutualism, both organisms benefit.
31According the respiration: In obligate aerobes, the prokaryotes must have oxygen to live.In obligate anaerobes, the organisms cannot survive in the presence of oxygen.And in facultative anaerobes they can survive with or without oxygen.
32According the shapes: cocci (spherical), bacillus (rod shaped), and spirillum (spirals).
33Classification of bacteria CocciMicrococcusStaphylococciIrregular clusters of cocciDiplococciPairs of cocciStreptococciChains of cocci
34Classification of bacteria BacilliRod likeDiplobacilliPairs of bacilliStreptobacilliChains of bacilliSpirochetesSpiral
36Size of bacteria Unit of microbial measurement micrometers (um)1 um being 10-6 m or m(1/25,000 inch)nanometers 1 nm being 10-9 or m.Pathogenic bacterial species vary from approximately 0.4 to 2 um in size
38TaxonomyTaxonomy is the classification of organisms. The most common system in use today is the Five Kingdoms:Monera (Prokaryota),Protista,Fungi,Plantae, andAnimalia.Organisms in each kingdom are divided into phyla.In each phylum, organisms are separated into classes.In each class, organisms are segregated into orders.In each order, organisms are divided into families.In each family, organisms are separated by genus.And finally, in each genus organisms are divided into species.Just remember that King Philip Can Order For Genial Students.
39Naming micoorganisms Binomial (scientific) nomenclature Gives each microbe 2 namesGenus - noun, always capitalized and may be abbreviatedspecies - adjective, lowercase, never abbreviatedA genus name may be used alone to indicate a genus group; a species name is never used aloneeg: Bacillus subtilis B. subtilisBoth italicized or underlinedStaphylococcus aureus (S. aureus)Bacillus subtilis (B. subtilis)Escherichia coli (E. coli)
40Nomenclature Common or descriptive names (trivial names) Names for organisms that may be in common usage, but are not taxonomic nameseg: tubercle bacillus (Mycobacterium tuberculosis)meningococcus (Neiserria meningitidis)Group A streptococcus (Streptococcus pyogenes)
45Historical YEAR NAME ACHIEVEMENT 1st century BC Varo Concept of “Animalia minuta”1546FracostoriusContagion- Cause of syphilis1590JensenHand lens1683Antony van LeeuwenhoekFirst Microscope“Animalcules”1678Robert HookCompound microscope1745Needham (Priest)Abiogenesis1836Schulze & SchwanAir contains microbes1840Oliver Homes, Poet physicianContageousness & Puerperal fever1846Ignaz SemmelweisCause, concept & prophylaxis of child-bed fever1853Augustino BassiSilk worm disease due to a fungus
46Pioneers of Microbiology Robert 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)Redi’s experiments first to dispprove S.G.
47Antonie van Leeuwenhoek First to observe living microbeshis single-lens magnified up to 300X( )
48Louis Pasteur (1822-1895) French chemist Father/Founder of Modern MicrobiologyFermentation – a microbiological processBeer/Wine not produced without microbesShowed microbes caused fermentation & spoilageDisproved spontaneous generation of m.o.Developed aseptic techniques.Developed a rabies vaccine.( )
50Joseph Lister 1867 Prof of Surgery, Glasgow Royal Infirmatory Introduced Antiseptic SurgeryCalled Father of Antiseptic Surgery
51Robert Koch (1843-1910) German general practitioner Perfected bacteriological techniquesIsolated pure cultures of bacteria for the first timeDiscovered Anthrax bacilli, Cholera vibrio, M. tuberculosisFather of Medical MicrobiologyHypersensitivityEstablished a sequence of experimental steps to show that a specific m.o. causes a particular disease.( )
53Highlights in the History of Microbiology 1900Proved mosquitoes carried the yellow fever agent (Walter Reed)1910Discovered cure for syphilis (Paul Ehrlich)1928Discovered Penicillin (Alexander Fleming)1887Invented Petri Dish(R.J. Petri)1892Discovered viruses (Dmitri Iosifovich Ivanovski)1899Recognized viral dependence on cells for reproduction (Martinus Beijerinck)
54Highlights in the History of Microbiology 1977Developed a method to sequence DNA (W. Gilbert & F. Sanger)1983Polymerase Chain Reaction invented (Kary Mullis)1995First microbial genomic sequence published (H. influenzae) (TIGR)