Microbiology exam 3

What is sterilization?

A process that destroys or removes all viable microorganisms, including viruses.

What does disinfection do?

It destroys vegetative pathogens but not bacterial endospores and removes harmful products of microorganisms from material.

What is decontamination/sanitization?

A cleansing technique that mechanically removes microorganisms and debris to reduce contamination to a safe level.

What is antisepsis/degermation?

It reduces the number of microbes on human skin and is a form of decontamination on living tissue.

What does autoclaving involve?

The process involves steam.

What are gamma and X rays classified as?

Ionizing radiation.

What is the definition of bacteriostatic?

Chemical agents that prevent the growth of bacteria on tissues or objects in the environment.

What is thermal death time?

The shortest length of time required to kill all microbes at a specific temperature.

What is thermal death point?

The lowest temperature required to kill all microbes in a sample in 10 minutes.

What are aqueous chemicals?

Chemicals dissolved in pure water as the solvent.

What are tinctures?

Chemicals dissolved in pure alcohol or alcohol-water mixtures.

What is the function of chlorine in microbial control?

Chlorine kills endospores slowly and combines with water to release HOCl to denature enzymes.

What is the role of iodine in microbial control?

Iodine kills endospores slowly and interferes with metabolic functions and bonding of proteins.

What is quinine used for?

It is the principal treatment for malaria, but no single drug is universally effective.

What is artemisinin?

A treatment for malaria.

What are probiotics?

Preparations of live microorganisms fed to animals and humans to improve intestinal biota.

What are fecal transplants used for?

To treat recurrent Clostridioides difficile infection and ulcerative colitis.

What is microbiota?

Normal microbial colonists of healthy body surfaces, mostly harmless with few pathogens.

What are broad-spectrum antimicrobials?

They destroy good biota as well as pathogens.

What is a superinfection?

When microbes that were small in number overgrow and cause disease.

What are true pathogens?

Microbes capable of causing disease in healthy persons.

What does virulence refer to?

The degree of pathogenicity.

What are exoenzymes?

Substances secreted by microbes that damage host tissue.

What is a toxin?

A chemical product of microbes that is poisonous to other organisms.

What are endotoxins?

Toxins found inside bacterial cells that are released when the cell lyses.

What is the incubation period?

The time from initial contact with the infectious agent to the appearance of symptoms.

What does selectively toxic mean?

Killing/inhibiting microbes without damaging host tissue.

What is the prodromal phase?

The 1-2 day period of earliest symptoms.

What is the Kirby-Bauer technique?

A method to measure the zone of inhibition on an agar plate.

What is the convalescent period?

The period during which a patient begins to respond to the infection and symptoms decline.

What are Koch’s postulates?

They are proofs that became the standard for determining the causation of infectious diseases.

What is a reservoir in the context of infectious diseases?

The primary habitat from which a pathogen originates (e.g., human, soil).

What type of drugs are tetracycline antibiotics?

Broad-spectrum drugs.

What is polymyxin?

A narrow-spectrum drug.

How does drug resistance develop?

Through spontaneous mutation and conjugation gene transfer.