Lecture 8 Flashcards
HD
All organisms can be grouped into a series of subdivisions that make up the what?
taxonomic hierarchy
One kind of microorganism, a subdivision of a genus.
Species
Consists of species that differ from each other in certain ways but are related by descent
Genus
All related genera make up a
Family
A group of similar families constitutes an
Order
A group of similar orders makes up a
Class
Related classes make up a
Phylum (PLURAL PHYLA)
Related phyla make up a
Kingdom or Domain
has been described qualitatively e.g. as a collection of genetically similar populations which are capable of genetic interchange, and or interbreeding, and which are evolving together in a common pattern
A species
A collection of cells derived from a single cell
Strain
Strains are identified by numbers, letters, or names that follow the ___________
specific epithet e.g. E.coli OP59.
True of False;
Sometimes the members of a bacterial species are essentially indistinguishable from other species of the same genus morphologically, and further testing is required to identify them.
True
The 18th century Swedish Botanist Carolus Linnaeus is credited with founding the science of taxonomy. He originated ________ _________ the system that is still used today to name all living things.
binomial nomenclature
In the binominal, or “two name” system the first name designates the ________ of an organism, and it’s first letter is _________
genus (plural: genera). Capitalized
The second name is the ___________. Is it capitalized or not? Derived from the name of the person who discovered it.
specific epithet, Capitlalized
The name of an organism often tells something about it, such as
- its shape,
- where is found,
- what nutrients it uses,
- who discovered it,
- or what disease it causes
Growth Dependent Identification methods
Identification of a clinical isolate can frequently be made using a variety of growth dependent assays. On the basis of growth characteristics in primary isolation media, an unknown pathogen is usually sub-cultured on diagnostically useful culture media
Sugar fermentation test: Fermentation of sugars is measured by incorporating what with what reaction?
pH indicator dyes that change color on acidification.
Triple Sugar Iron Agar (diagnostic test for enteric bacteria)
Hydrogen sulfide production is indicated following growth in a medium containing _______ _______. If sulfide is produced,______ ______complexes with H2S to form ______ precipitate of iron sulfide.
ferric iron, ferric iron, black
Production of hydrogen gas and/or carbon dioxide during sugar fermentation is assayed by observing what?
gas production either in gas collection vials or in agar
How many carbons and carboxylic groups does citric acid have?
6 carbons, 3 carboxylic groups
Utilization of citric acid is accompanied by a increase in what?
pH
A specific dye incorporated into the citric acid test medium changes color as conditions become what?
alkaline.