Module 1: Introduction to Clinical Microbiology Flashcards
Classification
Arrangement of organisms into taxonomic groups on the basis of similarities
Identification
Determining in which taxonomic group a new isolate belongs
Eukaryotic
“True nucleus”
Organized nucleus with membrane, several chromosomes
Prokaryotic
“Primitive nucleus”
Lack organized nucleus
Single circular chromosome
Order of taxonomic groups
Kingdom, division/phylum, class, order, family, tribe, genus, species
Family
Uses the ending -aceae
Tribe
Only used where there are a large number of bacteria in one family
Uses the ending -eae
Biotype (biovar)
Type of subspecies distinguished by biochemical or physiological properties that differ from the type strain
Serotype (serovar)
Type of subspecies distinguished by distinctive antigenic or serological properties that differ from the type strain
Key system
Used in early classification
Bacterial characteristics were identified and weighted
Base composition of nucleic acid
Percentage of guanine-cytosine in nucleic acid
Same species = same content (percentage)
Closely related species would have similar content
Nucleic acid hybridization
Heat to separate DNA strands, reunite when cooled
Mix strands from different organisms, degree of hybridization determines similarity between the two
Numerical taxonomy
Characteristics weighted equally
Percent of similarity
90% or higher usually indicates the same
