Microbiology 1 Flashcards
Microbiology
the study of microscopic forms of life
Microscopic groups
bacteria, fungi, protazoa, viruses
Pathogenicity
certain mircobes cause disease, learning how diseases are transmitted is important to health sciences.
Bioremediation
process using naturally occurring or genetically engineered microorganisms to degrade or detoxify environmental hazards (ex. oil spills)
Microbes biological roles
are essential to web of life, some are photosynthetic, others decompose dead organisms and some provide nitrogen to plants
Fundamental biology
microbiology provides insight into life processes of all life forms
Microbes
are useful in research, are prokaryotes
antibiotics
can be isolated from microbes (ex penicillium notatum)
genetic engineering
microbes can be used to create useful human proteins (ex insulin and HGH)
Characteristics of microbes
ubiquitous, microscopic, unicellular (some are multicellular), sexual and/or asexual reproduction, growth in number, metabolic activity, free living (some are parasitic), respond to stimuli, mutations, range in size from 20nm to 100um
Domains
Domain Archaea (extremeophiles), Domain Bacteria, Domain Eukarya
Microbe types
Bacteria, Algae, Fungi, Viruses, Protazoa
Bacteria
are unicellular, microscopic, some are photosynthetic, no nucleus, have 3 types of morphology
Bacteria shapes
round, rod, tight spiral, loose spiral, comma shaped
Round bacteria
cuccus, cocci
Rod shapes bacteria
bacillus, bacilli
Tight spiral shaped bacteria
spirochetes
Loose spiral shaped bacteria
spirillum
Comma shaped bacteria
vibrio
Algae
unicellular or multi-cellular, eukaryotic
Fungi
kingdom fungi, in domain eukaria, unicellular yeasts, multi-cellular molds, macroscopic (mushrooms), are an important source of antibiotics
Mushrooms
absorb their nutrients and decompose, no photosynthesis
Viruses
not living things, need host cell to reproduce, are more like complex chemicals, have neuclaic acid genome and protein capsid-“neucleoproteins”, obligate intracellular parasites
Protazoa
Eukaryotic organism, has many vacules and organelles, are motile, ameba
Robert Hooke & Anton Van Leeuwenhoek
Invented the first microscope, first to see living organisms under microscope, 1600’s. Hooke coined term “cell”
Carolus Linneaus
developed binomial nomenclature by using genus and species. Genus is capitalized, species is not, 1735
Compound light microscope
system of magnifying lenses arranged to produce an enlarged image of an otherwise invisible object, has two lenses (ocular and and objective)
Theodore Schwann
developed the cell theory
Cell theory
cells are the fundamental units of life and carry out the functions of living things
Germ theory of disease
microorganisms can invade other organisms and cause disease
Spontaneous generation
the belief that life can spontaneously arise from non-living matter
Redi
1668, disproved the theory that maggots come from meat
Needham
boiled chicken broth and put it into different containers to prove spontaneous generation for microbes in 1745
Spallanzani
repeated Needham’s experiment but containers, no bacteria formed, critics said it was because of lack of oxygen
Pasteur
1861, disproves spontaneous generation and proves biogenesis, also developed aseptic technique, pasteurization, rabies vaccine, fermentation
Biogenesis
all life comes from living things
Robert Koch
1884, developed pure culture technique
Koch’s postulates
- the specific causative agent must be found in every case of disease
- the disease organism must be isolated in pure culture
- inoculation of the culture into healthy susceptible animal must produce the same disease
- the disease organism must be recovered from the inoculated animal
Semmelweiss
1840’s, hand washing, pioneer of aseptic technique
Mortality and handwashing
handwashing use lowered mortality rate fom 10-35% to 1% in maternity ward
Lister
1860’s developed use of chemical disinfectants in surgery
Alexander Flemming
1928, discovered penecillin
Chemotherapy
treatment of a disease with a chemical
Antibiotics
microbe made chemicals
Synthetics
man made chemicals
Microscpoe
a system of magnifying lenses arranged in an order to provide a visible image of an otherwise non-visible object
Polio Virus size
20nm (0.02um)
Small Pox Virus size
300nm (0.3um)
Staphylococcus aureus
0.5um, typical coccus shape (round)
Pseudomonas aeruginosa
5um long, typical bacillus shape (oblong)
Treponema pallidum
20um long, very thin, spirochete shape
Resolution
R= λ / 2 x NA
NA
numerical aperture, a mathematical expression relating to the extent that light is concentrated by the condenser lens and collected by the objective
λ
wavelength, is directly proportional to resoulution, as the wavelength decreases, the resolving power increases
Important features of a microscope
magnification, resolution
Resolution
smaller numbers make a clearer image, is a number that indicates the smallest microbe or part of a microbe that can be viewed with clarity
Light microscopy
uses light as the illuminating source, uses glass lenses, λ=550nm
Electron microscopy
uses electrons as illuminating source, uses electromagnetic lenses, λ= 0.005nm, has 100,000 fold resolution than light microscopy
Light properties
light can be reflected, transmitted and absorbed, we want to avoid refraction
Index of refraction
speed at which light passes through material
Microscope types
compound bright field (compound light microscope), dark field, phase contrast, fluorescence, electron
Compound bright field
field of view is brightly lit, magnification=2,000x, resolution with oil objective=0.2um
Compound bright field uses
clinical, research, fixed and stained microbes
Compound bright field limitations
poor image production of viable microbes, can not see anything under resolution of 0.2um
Dark field microscope
light reflected off surface of specimen to view, background is dark, magnification=2,000x, resolution with oil objective=0.2um
Dark field uses
image production of viable microbes that are not easily stained or cultured in vitro
Major use: diagnosis of tetranemapalidum (syphilis) which is a clinical use
Dark field limitations
poor image production of classically fixed and stained microbes, can not see anything under resolution of 0.2um
Phase contrast microscope
dual beam-light comes from two sources
magnification=2,000x
resolution with oil objective=0.2um