Microbiology and Bacterial Characteristics

Vocabulary flashcards covering core concepts of microbiology, bacterial structures, modes of transmission, growth parameters, and environmental classifications.

Microorganisms

A varied group of microscopic unicellular or multicellular organisms capable of carrying out all their vital functions independently.

Vector

A living organism that participates as a transmitting agent of disease.

Fomites

Inanimate objects that act as vehicles or agents for transmitting disease.

Direct Transmission

Transmission of a pathogen via droplets of saliva when sneezing or coughing, or through intimate contact.

Indirect Transmission

Transmission of a pathogen through disease vehicles such as contaminated food and water, or inanimate objects (fomites).

Infection

The acquisition of a microbial agent that possesses the capacity to multiply inside a host.

Infectious Disease

A condition in which clear symptoms resulting from a microbial infection are observed.

Subclinical Infection

An infection in which no clear symptoms are observed in the host.

Plasmid

Small rings of DNA located outside the main chromosomal DNA in bacteria that contain extra genes.

Bacterial Capsule

An external protective shield present in some bacteria, located above the peptidoglycan cell wall or above a second membrane.

Gram Stain

A differential staining method used to categorize bacteria into Gram-positive and Gram-negative groups to guide antibiotic selection.

Septum

A dividing wall formed during bacterial reproduction that splits the progenitor cell into two daughter cells.

Psychrophiles

Microorganisms that develop between $-5^\text{o}\text{C}$ and $30^\text{o}\text{C}$, with an optimal growth temperature between $10^\text{o}\text{C}$ and $20^\text{o}\text{C}$.

Mesophiles

Microorganisms that develop between $10^\text{o}\text{C}$ and $45^\text{o}\text{C}$, with an optimal growth temperature between $20^\text{o}\text{C}$ and $40^\text{o}\text{C}$.

Thermophiles

Microorganisms that develop between $25^\text{o}\text{C}$ and $80^\text{o}\text{C}$, with an optimal growth temperature between $50^\text{o}\text{C}$ and $60^\text{o}\text{C}$.

Hyperthermophiles

Microorganisms that develop between $70^\text{o}\text{C}$ and $130^\text{o}\text{C}$, with an optimal growth temperature between $80^\text{o}\text{C}$ and $100^\text{o}\text{C}$.

Acidophiles

Microorganisms that grow best in media with a $\text{pH} < 5$ (optimal $\text{pH} = 3$) and maintain an internal $\text{pH} = 6.5$.

Neutrophiles

Microorganisms that proliferate best in a $\text{pH}$ range of $6$ to $8$ and maintain an internal $\text{pH} = 7.5$.

Alkaliphiles

Microorganisms that develop best in environments with a $\text{pH} > 9$ (optimal $\text{pH} = 10.5$) and maintain an internal $\text{pH} = 9.5$.