Microbiology Disciplines

• Microbiology studies microorganisms and agents too small for clear unaided vision.

Basic Disciplines in Microbiology

• Phycology studies algae, aquatic organisms ranging from single-celled forms to large seaweeds.
• Bacteriology studies bacteria,simplest, single-celled prokaryotic microorganisms which replicate through binary fission.
• Mycology studies fungi and microscopic eukaryotic forms like molds and yeasts.
• Cant be identified simply by microscope, other tests needed to determine if the organism is mold or yeast.
• Protozoology studies protozoans and mainly single-celled eukaryotic organisms.
• Virology the infectious agents containing DNA or RNA that replication/reproduction requires living cells.
• No virus has 2 genomes either DNA or RNA
• HIV = RNA but goes into nucleus becoming DNA then is called retrovirus
• Parasitology studies parasitism and parasites including pathogenic protozoa, helminth worms and some insects.

Applied Disciplines in Microbiology

• Agricultural Microbiology focuses on microbes and crops and control of plant diseases, enhancing yields.
• Food Microbiology studies microorganisms and food about bioprocessing, spoilage, and preventing foodborne illnesses.
• Dairy Microbiology involves ensuring good quality dairy products.
• Industrial Microbiology uses microbes in the production of alcoholic beverages, vitamins, amino acids, enzymes, antibiotics and other drugs.
• Marine Microbiology focuses on microorganisms and their activity in humans, animals in flesh, estuarine, and marine environments.
• Air Microbiology studies the role of aerospora in food contamination, spoilage, and plant & animal diseases spreading through the air.
• Exo Microbiology explores microbial life in outer space.
• Diagnostic Microbiology uses principles and techniques in the study of pathogenic organisms and diagnosis of infectious diseases.
• Epidemiology & Public Health Microbiology monitors, controls, and spreads knowledge of treating diseases in communities.
• Biotechnology manipulates living organisms to produce useful product.

History of Microbiology

• Robert Hooke (1665) developed the compound microscope and first described cells.
• Aristotle (383-322 B.C) believed that animals could originate from soil via "spontaneous generation" and life from nonliving things
• Francesco Redi (1668) disproved Aristotle's theory of spontaneous generation by demonstrating that maggots arise from flies, not decaying meat, using jars with that substance
• John Needham (1745) filled flasks with nutrient broth, heated them, and left them unsealed, resulting in microbial growth over time.
• Lazarro Spallanzani (1765) boiled nutrient solutions in flasks and sealed them, preventing microbial growth.

Theories in the Origin of Living Things

• Biogenesis was proposed by Rudolf Virchow in 1858 and states theory of development of living forms from other living things

Classical Golden Age of Microbiology

• Louis Pasteur (1850-1880) disproved spontaneous generation in 1861 with Swan Neck Flask Experiment and stated thatmicroorganisms are present in the air
• With the swan neck flask he used with a bend on top, there was no microbial growth on the broth while it remained unsealed but the bend had it

Koch's Pastulates

• Robert Koch (1843-1910) formulated criteria as proof a specific organism causes a disease (1876).
• Koch started studying a mice who had died and took blood, isolated killed cells and used microscope to identify cell
• Then injected cells into healthy mice to make them die with the same disease
• It ended with the mice dying from the same disease, proving microorganisms causes specific diseases
• Consisted of bacteria causing anthrax

Nobel Laureates

Charles Jules Henry Nicolle (1866-1936)

• Identified lice as the transmitter of epidemic typhus
• The experiment earned him a Nobel Other Notable people of note
• 1944 Joseph Erlanger and Herbert S. Gasser: Highly differentiated functions of single nerve fibres
• 1945 Sir Alexander Fleming, Ernst B: Discovery of penicillin and its curative effect in various infectious diseases
• Chain and Sir Howard Florey
• 1947 Hermann J. Muller: Production of mutations by means of X-ray irradiation Carl Cori, Gerty Cori and Bernardo Houssay
• 1948 Paul Müller: High efficiency of DDT as a contact poison against several arthropods
• 1949 Walter Hess and Egas Moniz: Discovery of the functional organization of the interbrain and the therapeutic value of leucotomy in certain psychoses
• 1950 Edward C. Kendall, Tadeus Reichstein and Philip S. Hench:Hormones of the adrenal cortex, their structure and biological effects
• 1951 Max Theiler: Yellow fever and how to combat it More information
• Alexander Flemming Discovered penicillin (1945): Base for antibiotics
• Edward Jenner: Pioneer of smallpox vaccine
• Emil Von Behring Prepared antitoxins for diphtheria and tetanus

Basics for Bacterial Cell

• Organization of microorganisms that share similar morphologic, physiologic & genetic traits into groups or taxa.
• KINGDOM has similar divisions
• DIVISION has composed of similar classes
• CLASS has composed of similar orders
• ORDER has composed of similar families
• FAMILY composed of similar genera
• GENUS composed of similar species
• SPECIES basic group with bacterial strains sharing common physiologic/genetic features
• Taxonomy: the orderly classification and organisms are grouped into taxa, based on Genotype/Phenotype

Basis of Classification for the Bacterial Cell

• Genotype = DNA/RNA (not readily observable)
• Phenotype = Observable trait such as black Hair
• Collection of bacterial that share common and various physiologic and genetic features
• Subspecies can be Biotype, Serotype, or Genotype

Binomial Systems

• Assigns every organism a two-part name, always capitalizing the genus and never capitalizing species designation
• Both are italicized or are underlined
• i.e. Streptococcus pneumoniae, Streptococcus pyogenes; S. pneumoniae, S. pyogenes

Common and Informal names

• Always memorize is gonococcus= Neisseria gonorrhoea
• The process by which the microorganisms key features are delineated so that it can be assigned a genus and a name, that include Genotyping and Phenotyping
• Three Microorganism Types: Prokaryotes, Eukaryotes, and Archaeobacteria.

Cell wall

• Cell walls never contain peptidoglycan but have S-layer
• do not contain nucleus and other organelles but contain gas vesicles and Grow in extreme conditions methanogens, halophiles and thermophiles
• Eukaryotes have membrane bound
• Prokaryotes: no nuclear membrane, in nucleoid
• No Pili unless prokaryote
• Outer most to deepest layers are: outer membrane, cell wall, Periplasm and plasma membrane

Cell Division and other key qualities

• Peptidoglycan aka murein layer maintainsshape composed of NAM and NAG
• Has teichoic acid alcohol for phosphates
• Gramm (+) = Cell wall single peptidoglycan layer
• Distinct Gram= has lipopolysaccharides = Major Comstituents: Lipid A, core polysaccharide, Antigenic O
• If gram+ has lipid A it can cause fever

Cellular distinctions

• Eukaryotes contain more cell components than prokaryotes
• Prokaryotes have Common Pili for attachment and Sex Pili for Conjugation

Axial Filamenents

• Axial movements move Axial filoamants to create spiriral motion
• Spirochetes are hard to view and require a dark feild microscope"
• Eukaryotes have "true nucleus"
• higher plants and some animals, fungi, contains membrane bound organelles include ER, golgi body, mitochondria and nucleus
• Sterilization removes infectious diseases but are made up of different factors
• Cocci is spherical or Ellipsoidal
• Basciili is Cylindrical or Rod shaped
• Spirochetes is Sprial

More on Basic Microbiology

• Cocci is a Sphere with:*
• Diplococci occurs in pairs*
• Streptococci arranged in Chains*
• Staphylococci in bunch of Grapes*
• Tetrads and carinae cube of more cells* Spirochetes: Vibrio: comma shaped* Spirillum: Loosely Coiled* Treponema: Tightly coiled
• Environmental Factors: pH, temp, gaseous atmosphtere, osmotic pressure

More on Oxygen Requirements

• Aerobe* use oxygen in room air Oligate (Needs more Oxygen)
• Anaerobic* needs No Oxygen Obligate (Does not require oxygen at all) Facultative: can exist without oxygen
• Aero* can exists either in presence or absence Bacterial Cell: Requires Heat, time, the organism presence, organic material on site