Bacterial Classification and Identification

Vocabulary flashcards covering bacterial taxonomy, key bacterial pathogens, diagnostic tests, and the use of dichotomous keys from the lecture.

Proteobacteria

A large and diverse group of gram-negative, chemoheterotrophic bacteria named after the Greek shape-shifting god Proteus because they can take on many morphological shapes.

Chemoheterotrophic

A metabolic classification for organisms that cannot manufacture their own food and must obtain chemical substances from external sources to survive.

Rickettsia

A genus of alpha-proteobacteria characterized as tiny gram-negative rods that act as obligate intracellular parasites, are transmitted by ticks, cause spotted fever, and can only be identified by methods such as PCR rather than routine lab culture.

Brucella

A representative genus of alpha-proteobacteria that acts as a parasite and causes the disease brucellosis.

Dichotomous Key

A diagnostic reasoning process used to systematically distinguish and identify unknown organisms through a progression of yes-or-no questions.

Ehrlichia

An obligate intracellular parasite belonging to the alpha-proteobacteria that causes disease in humans but does not cause spotted fever.

Neisseria gonorrhoeae

A gram-negative, oxidase-positive bacterium responsible for causing the disease gonorrhea.

Neisseria meningitidis

A gram-negative, oxidase-positive bacterium responsible for causing life-threatening meningitis.

Helicobacter pylori

An oxidase-positive, urease-positive curved rod with multiple flagella that colonizes the stomach, causing stomach ulcers and potentially leading to stomach cancer.

Leptospira

A genus of spirochetes responsible for leptospirosis, a disease against which animals are routinely vaccinated.

Oxidase Test

One of the earliest metabolic tests performed on gram-negative bacteria to determine enzyme activity and narrow down identification pathways on a dichotomous key.

Stain and Microscope

The cheapest and fastest initial laboratory testing procedure used to observe bacterial morphology before conducting metabolic tests.