Term
| Why do we study microbiology? |
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Definition
Found everywhere & an important part of our environment
Significant impacts on human and animal health.
Majority of microorganisms are BENEFICIAL
1) Studies of microorganisms can help us to understand processes in other life forms
Simpler to study (unicellular or simple multicellular) than complex life forms.
Can grow large numbers relatively quickly and easily |
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Term
| What is the Significance of microorganisms? |
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Definition
Important part of the food chain.
Aid in digestion & provide food for humans.
Produce valuable industrial products such as antibiotics and steroids.
Degrade organic waste and toxic materials.
Help us to understand genetic processes.
Important cause of human, plant and animal diseases. |
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Term
| Medical/Veterinary Microbiology |
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Definition
| Identification of microorganisms; prevention & treatment of disease |
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Definition
| Water purification, breakdown of waste materials |
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Definition
| Safe production of food; prevention of spoilage |
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Definition
| Production of e.g., enzymes or antibiotics |
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| Agricultural microbiology |
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Definition
| Understanding & dealing with plant diseases; understanding relationship between plants & microorganisms |
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Term
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Definition
| MICROSCOPIC life forms, i.e., we need a microscope to see them (most of them anyway). |
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Term
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Definition
Bacteria
Fungi
Viruses
Algae
Protozoa
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Term
| The major fields of study are? |
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Definition
| Bacteriology, Mycology, Algology, Protozoology |
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Term
Bacteria (plural)
Bacterium (singular) |
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Definition
Single celled organisms
NO cell nucleus: PROKARYOTIC
Reproduce ASEXUALLY
Size range: micrometers (1 μm = 0.000001 cm or 1/100,000th of a cm)
Can absorb nutrients or synthesize their own
Can be MOTILE or NON-MOTILE |
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Term
Fungi (plural)
Fungus (singular) |
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Definition
Yeasts
True nucleus: EUKARYOTIC
Unicellular
Reproduce asexually (cell division), budding or sexually
>Moulds
Eukaryotic
Multicellular
Reproduce sexually & asexually |
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Term
Viruses (plural)
Virus (singular) |
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Definition
ACELLULAR
Composed of nucleic acid (DNA or RNA) and proteins
Can’t replicate outside of a host cell (INTRACELLULAR PARASITES)
Size range: nanometers (1 nm = 0.000000001cm or 1/100 millionth of a cm) |
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Term
Algae (plural)
Alga (singular) |
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Definition
Single celled or multicellular
Eukaryotic
Size range: micrometers to feet
Photosynthesize for food production
Not medically important |
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Term
Protozoa (plural)
Protozoan(singular) |
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Definition
Unicellular
Eukaryotic
Size range: micrometers to mm
Reproduce asexually & sexually |
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Definition
(1632 – 1723) Created early single-lens microscopic
One of first to describe microscopic organisms “animacules” |
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Term
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Definition
the idea that life can arise from nothing (abiogenesis)
Theory (Aristotle): life arose spontaneously from dead organic matter |
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Term
| Francesco Redi & Lazzaro Spallanzani |
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Definition
| Redi challenged the theory of spontaneous regeneration by covering meet with a fine mesh. Spallanzani boiled broth in a sealed container. Neither experiences convinced the public |
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Term
| Louis Pasteur & spontaneous generation |
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Definition
| killed spontaneous generation by the invention of the swan necked flask that trapped bacteria in the neck of the flask |
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Definition
Determined how the process of fermentation worked, Eduart with Buchner
made the rabies vaccine |
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Definition
Credited with “parasite/germ” theory of disease; was the 1st to demonstrate microorganisms could cause disease
<>brDescribed fungus associated with an epidemic disease of silkworms |
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Definition
Further clarified relationship between microorganisms and disease
Vaccine for B. anthracis and tuberculosis
developed a series of criteria called Koch’s Postulates. |
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Term
| What are the 4 Koch Postulates? |
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Definition
1.The suspected causative organism should always be present along with the specific disease and absent in healthy animals
2.The suspected organism can be grown in pure culture
3.Organisms taken from the pure culture should cause disease in a healthy animal
4.The organism can be re-isolated and shown to be the same as the original. |
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Term
| When do Koch's postulates not work? |
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Definition
When there is no animal model
When the organism is unculturable
When organism is normal flora but opportunistic |
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Definition
Brought the practice of variolation back from Ottoman Empire
Used for prevention of smallpox |
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Definition
Observed that milkmaids exposed to cowpox while milking rarely contracted smallpox.
"father of vaccines"
Tested theory by inoculating small boy with material from cowpox lesions
Then exposed the boy to smallpox |
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Definition
Father of modern epidemiology
Identified source of cholera outbreak in London |
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Definition
| Identified that handwashing decreased infection rates in hospital patients. (milk fever) |
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Definition
Recognised important of Pasteur’s work & applied it with regard to control of infections.
Theorised: infections of open surgical wounds = due to microorganisms in air.
Used early aseptic technique: sprayed air with carbolic acid (phenol) |
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Definition
Searched for “magic bullet” to kill microorganisms without harming humans.
Initiated branch of medical microbiology called “chemotherapy” |
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Definition
| (Re)Discovered of penicillin |
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Definition
Discovered an antimicrobial dye (prontosil)
long with Fleming, laid the groundwork for modern antimicrobial chemotherapy (use of antibiotics) |
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Definition
| population of microorganisms (also used to describe the techniques for growing bacteria) |
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Definition
| Population containing only one type (species) of microorganism |
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Definition
Population containing >1 species of microorganisms.
In natural environments, most microorganisms exist as mixed culture |
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Term
| Features used for characterisation of mircoorganisms? |
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Definition
Morphological
Chemical
Cultural
Metabolic
Antigenic
Genetic
Pathogenicity
Ecological |
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Term
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Definition
Cell size, shape & structures
Cell arrangement
Staining reaction
Motility
Developmental forms |
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Definition
Presence of proteins, carbohydrates, etc.
Enzymes |
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Definition
Nutritional requirements
Physical conditions required for growth |
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Definition
How energy is obtained and used
Types of chemical reactions |
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Definition
| Determination of antigenic properties |
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Definition
Characteristics of hereditary material
Presence of other genetic information, e.g., plasmids |
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Definition
| Ability to cause disease. Not all microorganisms are pathogenic! |
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Definition
Habitat & distribution in nature
Interaction with other species |
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Term
| What system do we use for classifying microorganisms? |
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Definition
Currently accepted: Carl Woese’s 3 DOMAINS system
Uses 16S RNA for differentiation
(Phylogenetic characterisation) |
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Definition
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Term
| The system by which we name Bacteria? |
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Definition
TAXONOMY: Carolus Linnaeus’s classification. Sometimes called “bionomial classification” (literally “two names”).
= formal system of ordering, classifying & naming |
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Term
| In taxonomy the seven descending groups after the Domain are? |
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Definition
| Kingdom > Phylum > Class > Order > Family > Genus > Species |
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Term
| What must we know in order to identify a bacteria to species and genus level |
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Definition
Uses a combination of:
1.Physical characteristics
2.Growth and energy requirements
3.Metabolic processes carried out
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Term
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Definition
Process of transferring or introducing microbial cells into fresh growth media.
What’s being transferred = the inoculum. Sources might be:
CLINICAL SAMPLE - blood, urine, CSF, feces, etc
2.HABITAT SAMPLE - soil, water, sewage, food, etc
3.EXISTING PURE CULTURE - from ATCC culture collection or frozen stocks |
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Definition
| Place the Microorganism in conditions necessary to obtain growth |
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Definition
| Tool being used to innoculate |
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Term
| Blood, urine, CSF, feces, etc. |
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Definition
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Term
| Soil, water, sewage, food, etc |
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Definition
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Term
| From ATCC culture collection or frozen stocks |
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Definition
| EXISTING PURE CULTURE (reference microbes) |
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Term
MEDIA (plueral)
Medium (singular) |
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Definition
Function: to provide the nutrients that will enable the microorganisms to grow.
Can be: liquid, semi-solid, or solid. |
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Term
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Definition
| Water based solutions, do not solidify at temperatures above freezing, flow freely in containers, ie: BROTHS, MILKS |
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Term
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Definition
Mid-way between liquid and solid.
Soft custard-like consistency
Exact solidity depends on amount of solidifying agent (agar/gelatin - 0.3-0.5%)
Uses: to determine motility, localize reaction at specific sites |
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Term
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Definition
Firm, set jelly-like surface, allows cells to form discrete colonies
Necessary for ISOLATION & SUBCULTURING
Liquid media can be converted to solid media by addition of a gelling agent –usually AGAR – before media is autoclaved.
Solid media is sometimes referred to just as “agar”.
Agar = powdered seaweed. |
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Term
| What are the 2 Forms of solid media? |
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Definition
LIQUEFIABLE: reversible solid, agar, thermoplastic
NON LIQUEFIABLE: NOT thermoplastic ie. cooked meat, potato slices, egg media. |
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Definition
Precise amounts of inorganic compounds added to water
Usually contains single carbon source. |
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Definition
Mixture of inorganic and organic compounds
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Term
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Definition
contains 1 or more inhibitory agents
e.g., dyes, acid, antibiotics. Examples:
MANNITOL SALT AGAR - 7.5% NaCl, inhibitory to most human pathogens
SABOURAUD’S AGAR (for growth of Fungi) - pH 5.6 (acid); inhibits bacteria by including antibiotics. |
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Term
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Definition
Allows for growth of several types BUT highlights differences between them.
(e.g., based on colony colour, formation of gas or a precipitate)
CONTAINS DYES (differential agents) - act as pH indicators, colour change due to production of acid or base
Example: EMB agar |
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Term
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Definition
Both Selective & differential
o Selective due to: High Bile salt concentration (prevents growth of Gram +ve bacteria).
Differential due to: inclusion of lactose and neutral red (a pH indicator). Production of acid as the bacteria utilize the lactose changes the pH indicator and produces pink colonies |
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Term
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Definition
| Addition of Thioglycollic acid or cystine absorbs oxygen/slows penetration of oxygen THUS reducing availability = REQUIRED for growing ANAEROBIC BACTERIA |
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Term
| CARBOHYDRATE FERMENTATION media |
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Definition
| Specific sugars included to look for bacterial ability to ferment them, producing acid and/or gas.
REQUIRED for BIOCHEMICAL/IDENIFICATION TEST |
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Term
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Definition
Maintains and preserves samples from when they are taken until they get the lab for culture.
Examples: STUART’S + AMIES contains salts, buffers & absorbents. Prevents cell destruction, pH changes, toxic substances. Doesn’t actually support growth. |
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Definition
Used when carrying out specific tests
e.g, looking at effectiveness of antimicrobial agents such as disinfectants or antibiotics |
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Definition
| Used in food and water industry: allows enumeration (counting) of organisms in milk, water, food and soil samples |
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Definition
| enlarging the appearance of an object |
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Term
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Definition
| the ability of an optical system to form distinguishable images of objects separated by small angular distances. |
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Term
| What are the different types of Light Microscopes? |
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Definition
Brightfield: Extensively used; enables viewing of stained specimens
Epifluorescent:Specimen stained with a certain dye; viewed using a special filter
Darkfield:Eliminates need for staining; provides contrast between specimen and background
Phase Contrast:Eliminates need for staining; can view both structures and living organisms
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Term
| What are the different tapes of Electron Microscopes? |
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Definition
Scanning Electron Microscope:Surface detail and 3D images
Transmission Electron Microscope:Ultrastructure. Very high magnifications possible
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Term
| What is the microscope that is has a laser and can produyce 3D images? |
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Definition
| Confocal Scanning Laser Microscope: Ultrastructure; 3D images! |
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Term
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Definition
| process involving the application of chemical STAIN/DYE to a specimen |
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Term
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Definition
imparts colour to cell or cell parts - become affixed through chemical
reaction
2 types:
1. BASIC (cationic) +ve charge: E.g., Crystal violet, methylene blue, Safranin.
2. ACIDIC (anionic) -ve charge: E.g., Nigrosin, India Ink. |
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Term
| What is the principle of staining? |
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Definition
“opposites attract”
POSITIVE STAINING: +ve stain - sticks to specimen providing colour
NEGATIVE STAINING: -ve stain - (reverse) settles around specimen boundary forms a silhouette (stains the glass slide) |
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Term
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Definition
| a single stain/dye, uncomplicated procedure |
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Definition
2 colored dyes, a primary and a counter stain: more complex procedure.
Distinguishes cell types and parts |
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Term
| TYPES OF DIFFERENTIAL STAIN (for bacteria |
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Definition
| Gram's stain & acid fast stain |
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