chapter 10 vocab

Taxonomy

The science of characterizing and naming organisms and arranging them into hierarchical groups (taxa); includes identification, classification, and nomenclature.

Identification

The process of characterizing an isolate to determine the group (taxon) to which it belongs.

Classification

The process of arranging organisms into similar or related groups (taxa).

Nomenclature

The system of assigning names to organisms.

Bacteria

One of the three domains; unicellular prokaryotes that lack a membrane-bound nucleus, generally have peptidoglycan in their cell walls, and have 70S ribosomes.

Archaea

One of the three domains; unicellular prokaryotes distinct from Bacteria that lack peptidoglycan and have 70S ribosomes and distinctive membrane lipids.

Eukarya

One of the three domains; organisms whose cells contain a membrane-bound nucleus and membrane-bound organelles and generally have 80S ribosomes.

Phenotype

The observable characteristics or traits of an organism, such as morphology, staining characteristics, culture characteristics, and metabolic capabilities.

Morphology

The size, shape, arrangement, and physical appearance of a microorganism, especially when viewed microscopically.

Culture characteristics

Characteristics of microbial growth in culture that provide clues to identity, such as colony color, pigment, odor, appearance, hemolysis, or growth on differential media.

Biochemical tests

Tests used to determine the metabolic capabilities of a microorganism, such as which sugars it ferments, enzymes it produces, or metabolic end products it makes.

Serological tests

Tests that use antibodies to detect specific microbial proteins or polysaccharides that can serve as identifying markers.

Protein profile

A characteristic pattern or fingerprint of a microorganism's proteins that can be compared with a reference database to identify the organism; MALDI-TOF MS can be used.

Genotype

The genetic makeup or genetic characteristics of an organism; genotype-based identification examines DNA or RNA.

NAATs

Nucleic acid amplification tests that increase the number of copies of specific nucleotide sequences so they can be detected and used as identifying markers; PCR is an example.

FISH

Fluorescence in situ hybridization; a technique using fluorescently labeled probes to detect specific nucleotide sequences within intact cells, often targeting 16S rRNA.

rRNA sequencing

Analysis of ribosomal RNA or the DNA encoding it to identify microorganisms and determine evolutionary relationships; 16S is especially useful for bacteria and archaea and 18S for eukaryotes.

Whole genome sequencing

Sequencing an organism's entire genome to identify an isolate, determine genetic relatedness, and potentially predict antibiotic resistance.

G + C Content

The percentage of guanine-cytosine base pairs in an organism's DNA; it can be used to roughly compare genetic relatedness.

Antibiograms

Antimicrobial susceptibility patterns that show which antimicrobial drugs inhibit or kill an organism and can be used to distinguish different strains.