Microbiology: Biofilms and Toxins

A sticky community of bacteria attached to a surface, embedded in a protective layer.

A toxin produced inside a bacterium during growth, then released into the environment.

A toxin part of the gram-negative bacteria cell wall released when the cell dies.

A 3 step process of bacterial cells attaching to a surface, developing into 3D structure, and eventually detaching to extend to new locations.

Bacteria with a cell wall that contains peptidoglycan and no outer membrane; exotoxins are produced from them.

Bacteria with a cell wall containing peptidoglycan and an outer membrane, endotoxins are from them.

The invasion or colonization of the body by pathogenic microorganisms; often without symptoms.

Pathological changes and visible symptoms resulting from a host-organism interaction.

A bacterial species' ability to cause disease.

The degree of pathogenicity determined by factors like virulence factors.

Live freely in nature; do not usually cause disease.

Always cause disease.

Live in or on a living host without causing disease.

Live in or on a living host, likely causing disease.

Potential pathogens causing disease under specific conditions (like weakened immunity or changing habitats).

Released by living bacteria, both Gram-positive and Gram-negative.

Part of the Gram-negative bacteria cell wall, released when bacteria dies.

Found on chromosomes, plasmids, or phages (bacterial viruses).

Found only in the bacteria's main chromosome.

Very strong immune response.

Weak or poor immune response.

Protein based.

Lipopolysaccharide (LPS) molecule, specifically lipid A.

Easily destroyed by heat.

Resistant to heat.

Can be converted into a toxoid.

Cannot be converted into a toxoid.

Has a specific target or action.

Non-specific action. Causes general symptoms.

Highly toxic.

Relatively low toxicity.

Structures allowing bacteria to attach to host surfaces.

Allow bacterial attachment to surfaces like heart valves (staphylococci, streptococci).

Allow E. coli attachment to urinary tract.

Enable bacteria to invade host tissues via enzymatic activity.

Found in staphylococci and neutralizes harmful oxygen.

Destroys immune cells (PMNLs, macrophages).

Breaks down IgA antibodies, evading immune response.

Breaks down DNA to aid tissue invasion.

Factors helping bacteria evade the host's immune cells.

A protective layer preventing phagocytosis.

Protect bacteria from the immune system (e.g., Staphylococcus, Streptococcus).

Makes clots to hide bacteria.

A group of bacteria embedded in a protective substance.

The origin of a disease-causing microorganism, including exogenous (outside the body), endogenous (from normal flora), or from a hospital (nosocomial), community, environment, or living being(s).

How a disease-causing microorganism spreads from one host to another, including contact, droplet, airborne, ingestion, and vector-borne methods.

The specific site where a pathogen enters the human body, such as mucosal membranes, skin, or parenteral route.

The route by which a pathogen leaves the host, including urine, stool, blood, and secretions.

Transmission of infection through physical touch between an infected and a healthy person.

Transmission of infection through contact with contaminated objects.

Transmission of infection through large droplets expelled during coughing or sneezing, traveling short distances.

Transmission of infection through small, airborne particles (droplet nuclei) that can travel long distances.

Transmission of infection through the consumption of contaminated food or water.

Transmission of infection through an intermediary organism, like a mosquito.