Bacteria Classification and Nomenclature

Flashcards covering the classification, nomenclature, morphological types, and environmental growth factors of bacteria.

Classification

The process of systematically dividing organisms into groups, with the species being the smallest and most definitive level of division.

Nomenclature

The process of naming an organism by international rules according to its characteristics.

Identification

The practical use of a recognised classification scheme to isolate and identify the causative agent of a disease to permit targeted pharmacologic treatment.

Kingdom Procaryotae (Monera)

The oldest known cells that lived over $3.5 \text{ billion}$ years ago; they lack a nucleus and membrane-bound organelles.

Kingdom Protista

Mostly unicellular organisms that lack tissue organization and typically possess flagella during their life cycle.

Kingdom Fungi

Organisms that may be unicellular (yeasts) or multicellular (molds) and are often saprotrophs.

Kingdom Plantae

Multicellular, photosynthetic organisms.

Kingdom Animalia

Multicellular heterotrophs that ingest food through a mouth or oral cavity.

Eubacteria

Known as 'True bacteria,' these have cell walls containing peptidoglycan and are sensitive to antibiotics.

Archaeabacteria

Known as 'Ancient bacteria,' these live in extreme environments, lack peptidoglycan in their cell walls, and are resistant to antibiotics.

Methanogens

A sub-kingdom of Archaeabacteria consisting of strict anaerobes that produce methane.

Extreme Halophiles

Archaeabacteria that require high salt concentrations to survive.

Thermoacidophiles

Archaeabacteria that live in hot, acidic environments.

Prokaryotic Cells

Primitive cells that are less complex, have a lower degree of organization, and contain no membrane-bound organelles.

Eukaryotic Cells

Complex cells evolved from prokaryotes that contain many organelles and a true nucleus separated from the cytoplasm by a membrane.

Binary fission

The method of cell division utilized by prokaryotes.

Mitosis

The method of cell division utilized by eukaryotes.

Binomial nomenclature

A universal system developed by Carl Linnaeus where each organism is given a two-part name consisting of a capitalized Genus (noun) and a lowercase species (adjective).

Bacterial species

A population of cells with similar characteristics.

Bacterial strain

A subgroup of a bacterial species with distinguishing characteristics, identified by numbers, letters, or names (e.g., E. coli O157:H7).

Bergey’s Manual

A reference used for identifying and classifying bacteria based on morphology, metabolism, biochemistry, and sequence analysis.

Cocci

Spherical or oval-shaped bacterial cells.

Diplococci

Cocci arranged in pairs, such as Streptococcus pneumoniae.

Staphylococci

Cocci arranged in grape-like clusters, such as Staphylococcus aureus.

Streptococci

Cocci arranged in chains, such as Streptococcus pyogenes.

Tetrad

Cocci arranged in a group of four, such as Micrococcus spp.

Sarcina

Cocci arranged in a group of eight, such as Clostridia.

Bacilli

Rod-shaped bacteria.

Actinomycetes

Rigid organisms appearing like sun rays that exhibit branching and form filaments, resembling fungi.

Spirochaetes

Long, slender, spiral-shaped microorganisms with several coils.

Mycoplasmas

Bacteria that lack a rigid cell wall and are highly pleomorphic with indefinite shapes.

Rickettsiae and Chlamydiae

Very small obligate parasites that were once considered related to viruses but are now classified as bacteria.

Fastidious

Bacteria that require extra growth factors for cultivation, such as Hemophilus influenzae.

Alpha-hemolysis

Partial hemolysis on Sheep Blood Agar, characteristic of Streptococcus pneumoniae.

Beta-hemolysis

Complete hemolysis on Sheep Blood Agar, characteristic of Streptococcus pyogenes.

Psychrophiles

Bacteria that grow at low temperatures between $15-20^{\circ}C$.

Mesophiles

Bacteria that grow at moderate temperatures between $20-40^{\circ}C$, including most human pathogens.

Thermophiles

Bacteria that grow at high temperatures between $50-60^{\circ}C$.

Obligate aerobes

Bacteria that strictly require oxygen ($O_2$) for growth.

Microaerophilic

Bacteria that grow under reduced oxygen ($5-10\%$), such as Campylobacter jejuni.

Facultative anaerobe

Bacteria capable of growing in either the presence or absence of oxygen, such as E. coli.

Obligate anaerobe

Bacteria that cannot grow in the presence of oxygen, such as Clostridium spp.

Capnophilic

Bacteria requiring an increased concentration of $CO_2$ ($5-10\%$) for growth.

Acidophiles

Bacteria that prefer acidic environments, such as Lactobacillus acidophilus.

Alkaliphiles

Bacteria that prefer alkaline environments, such as Vibrio.