Chapter 10: Identifying & Classifying Microorganisms

Species

A group of closely related strains or individuals

Genus

A collection of similar species

Family

A collection of similar genera. In prokaryotic nomenclature, the name of the family ends in the suffix -aceae

Order

A collection of similar families. In prokaryotic nomenclature, the name of the order ends in the suffix -ales

Class

A collection of sililar orders

Phylum

(sometimes called a division) A collection of similar classes

Kingdom

A collection of similar phyla or division

Domain

A collection of similar kingdoms. The domain reflects the characteristics of the cells that make up the organism.

Cytoplasmic membrane lipids (archaea)

Hydrocarbons (not fatty acids) linked to glycerol by ether linkage

Cytoplasmic membrane lipids (bacteria)

Fatty acids linked to glycerol by ester linkage

Cytoplasmic membrane lipids (eukarya)

Fatty acids linked to glycerol by ester linkage

Metabolic capability determination

Revealed by biochemical tests like the catalase test or pH indicators, relies on a dichotomous key

Fluorescence in situ hybridization (FISH) probes

Used to determine if DNA and unknown DNA strand is binded

Whole Genome Squencing (WGS)

Advances in DNA sequencing methods have made it easier to detect subtle differences among phenotypically identical strains.

PulseNet

A CDC network that tracks foodborne disease outbreaks

Genome Trakr

An FDA-associated network of laboratories

Global Microbial Identifier

a database of WGS data from around the world

Phage Typing

Relies on differences in bacteriophage susceptibility

DNA-DNA Hybridization

Relatedness of organisms determined by similarity of nucleotide sequences

G + C content

Percentage of G-C base pairs in DNA