Microbiology Practice Flashcards

Sixty vocabulary flashcards covering prokaryotic and eukaryotic cells, microbial types, structures, virulence factors, disease stages, and control methods based on the lecture notes.

$70S$ ribosomes

The specific type of ribosomes found within bacterial cells.

$80S$ ribosomes

The specific type of ribosomes characteristic of eukaryotic cells.

Peptidoglycan

The cell-wall material in bacteria that is thick in gram-positive and thin in gram-negative organisms.

Nucleoid

The area within a bacterial cell that contains the DNA.

Endospore

An inactive, protective survival form produced by some bacteria.

Chemotaxis

The movement of a bacterium toward or away from chemicals.

Sporulation

The developmental process of a vegetative cell turning into a mature endospore.

LPS

A component of the gram-negative outer membrane; its lipid A part acts as an endotoxin.

Lipid A

The part of LPS in gram-negative outer membranes that acts as an endotoxin causing fever and shock.

Hyphae

The individual filaments that make up the body of a fungus.

Dimorphic fungus

A fungus that can grow as either a yeast or a mold, such as Histoplasma capsulatum.

Monoecious

An organism that possesses both male and female reproductive organs.

Dioecious

A condition where male and female reproductive organs are located in separate organisms.

$$ID_{50}$$

The number of microbes required to infect $50\%$ of a test group.

$$LD_{50}$$

The number of microbes required to kill $50\%$ of a test group.

Primary pathogen

A pathogen capable of causing disease in healthy individuals.

Antigenic drift

Small, gradual mutations occurring in viral antigens.

Antigenic shift

A major change in viral antigens resulting from the reassortment of viral genomes, which can cause pandemics.

Mycotoxins

Fungal toxins that can damage organs, cause cancer, or suppress immunity.

Septicemia

A condition where bacteria are multiplying in the blood, resulting in serious systemic illness.

Exoenzymes

Secreted enzymes that help pathogens invade tissues and obtain nutrients.

Endotoxin

A heat-stable toxin, specifically the lipid A part of LPS in gram-negative outer membranes, released when cells die or divide.

Exotoxin

A powerful, usually heat-sensitive protein secreted by living gram-positive or gram-negative bacteria.

Superantigens

Toxins that overstimulate T cells, causing excessive cytokine release and severe inflammation.

Quorum sensing

Cell-to-cell communication in microbes based on population size, utilizing autoinducers.

EPS

Extracellular polymeric substances; the sticky material made of sugars, proteins, and DNA that holds biofilms together.

TEM

Transmission Electron Microscope; uses electrons passing through a thin specimen to show internal structures.

SEM

Scanning Electron Microscope; scans the specimen surface to provide detailed $3D$ images.

Mordant

A substance like iodine that fixes a dye into a specimen during the staining process.

Extremophiles

Organisms adapted to live in extreme environmental conditions.

Rhizosphere

The soil area around plant roots where microbes assist plants in accessing nutrients.

Mutualism

A symbiotic relationship in which both species benefit from the interaction.

Commensalism

A symbiotic relationship where one species benefits while the other remains unaffected.

Resident microbiota

The microorganisms that normally live in or on the body over the long-term.

Iatrogenic disease

A disease that is the direct result of medical care or a medical procedure.

Nosocomial disease

A disease acquired specifically within a healthcare setting.

Vertical transmission

The transmission of a pathogen from a parent to a child.

Fomite

A nonliving object that facilitates the spread of microbes.

Definitive host

The host in which a parasite reaches its state of sexual maturity.

TORCH infections

A group of infections that can cross the placenta, including Toxoplasmosis, Rubella, Cytomegalovirus, and Herpes simplex.

Adhesins

Attachment factors used by pathogens, such as pili, fimbriae, capsules, and viral proteins.

Incubation period

The period after infection during which the host has no symptoms.

Prodromal period

The disease stage where the host experiences mild or general symptoms.

Convalescence

The final stage of disease characterized by recovery.

PAMPs

Common pathogen structures, such as peptidoglycan and flagellin, recognized by the innate immune system.

Morbidity

A state of illness or the rate of disease within a population.

Prevalence

The total number of existing cases of a disease at a specific time.

Etiologic agent

The specific microorganism or cause of a disease.

Index case

The first identified case in a disease investigation.

D-value

The amount of time required to kill $90\%$ of microbes under specific conditions.

HEPA filter

High-efficiency particulate air filters that remove tiny particles and microbes from the air.

Selective toxicity

The ability of a drug to harm a target microbe more than the host.

Gram stain

A staining technique used to classify bacteria as gram-positive or gram-negative, revealing their shape and arrangement.

Acid-fast stain

A differential stain used to identify bacteria with waxy mycolic acids in their cell wall, particularly Mycobacterium species like tuberculosis.

Endospore stain

A special staining technique used to detect endospore-forming bacteria, commonly Bacillus and Clostridium.

Wet mount

A technique for examining a living sample under a microscope to observe motility and live microorganisms like fungi or protozoa.

Capsule stain

A staining method used to visualize bacterial capsules, aiding in the identification of encapsulated bacteria that evade phagocytosis.

Negative stain

A staining technique used to observe the size and outline of cells or capsules without heat-fixing, preventing distortion.

Simple stain

A basic staining method used to visualize the shape, size, and arrangement of bacterial cells.

Differential stain

A method that distinguishes between different types of microbes based on structural differences, including Gram and acid-fast stains.

Synergism

A scenario where two or more drugs work together to produce a greater effect than the sum of their individual effects.

Antagonism

A condition in which one drug reduces or counteracts the effect of another drug, leading to decreased efficacy.

Drug inactivation

Enzymes destroy or modify the drug; for example, β-lactamase breaks down β-lactams.

Blocked entry/efflux

Mechanisms that prevent drug entry into the cell or pump the drug out, rendering it ineffective.

Target modification

Changes in the target site of a drug that prevent the drug from binding effectively.

Target overproduction/bypass

Increased production of the target or the use of an alternative pathway to evade drug action.

Target mimicry

The production of a fake target that protects the real target from drug action.

MDR (Multidrug Resistance)

A condition where an organism is resistant to multiple classes of drugs, making treatment challenging.

Humoral immunity

The aspect of immunity mediated by B cells and antibodies, primarily targeting extracellular pathogens.

Cellular immunity

The type of immunity that involves T cells attacking and destroying infected or cancerous cells.