Untitled Flashcard Set

What is an antiseptic?

A chemical used on living tissue to reduce or eliminate microorganisms. ex: alcohol & hydrogen peroxide

Define aseptic.

An environment or procedure free of contamination by pathogens.

What is degerming?

The process that reduces almost all microbes but does not completely remove them, like hand-washing with soap.

What does disinfection do?

Inactivates most microbes on surfaces using antimicrobial chemicals or heat.

Define pasteurization.

A gentle heating process to kill pathogens and spoilage organisms in food and drinks.

What is sanitation?

Lowering microbial counts to safe public health levels.

What is sterilization?

The complete destruction or removal of all microorganisms, including endospores.

What is the difference between a fungicidal agent and a fungistatic agent?

A fungicidal agent kills fungi, while a fungistatic agent only inhibits their growth.

How do antimicrobials work?

They damage cell walls or membranes and interfere with protein or nucleic acid synthesis.

What are the characteristics of the ideal antimicrobial?

Fast acting, stable, easy to prepare, inexpensive, and easy to use.

What factors affect antimicrobial efficacy?

Environment (temperature, pH) and microbial susceptibility.

How does heat kill microbes?

By denaturing proteins and destroying cell membranes.

How does desiccation differ from lyophilization?

Desiccation removes water with heat; lyophilization removes water by freezing and vacuum drying (perserves shape and allows rapid rehydration).

How does osmotic pressure stop microbial growth?

It draws water out of cells, dehydrating and killing them

What type of microbe survives well with high osmotic pressure?

halophiles 

How does radiation kill microbes?

By damaging DNA and causing mutations or breaks in nucleic acids.

Who discovered antibiotics from Streptomyces?

Waksman.

Who discovered penicillin?

Fleming.

Who discovered sulfanilamide?

Domagk.

Who used arsenic compounds as ‘magic bullets’?

Ehrlich.

What are natural antibiotics?

Antibiotics produced by microorganisms in nature, such as fungi.

What are semisynthetic antibiotics?

Chemically modified derivatives of natural antibiotics.

What are synthetic antibiotics?

Antibiotics completely manufactured by chemical synthesis, not found in nature. man-made

Define selective toxicity.

Drugs harm the microbe without damaging the host.

Why are there more antibiotics effective against bacteria than eukaryotic pathogens and viruses?

Bacteria are prokaryotic and structurally different from human cells, whereas eukaryotes and viruses are similar to host cells.

List the six mechanisms of antibiotic action.

1. Inhibit cell wall biosynthesis. 2. Inhibit protein biosynthesis. 3. Disrupt membranes. 4. Antimetabolites. 5. Inhibit nucleic acid synthesis. 6. Mycobacterial ATP synthase inhibitor.

What is the ideal antibiotic?

Selectively toxic, stable, easy to administer, effective in low doses, and not lead to resistance.

What is a narrow-spectrum antibiotic?

Antibiotics that target a specific set of bacteria. (only target gram-positive bacteria or target only gram-negative bacteria).

What is a broad-spectrum antibiotic?

Antibiotics that target a wide variety of bacteria. both gram-positive and gram-negative), and is used as to cover a wide range of pathogens while waiting on the laboratory identification of the infecting pathogen.

Is there a disadvantage to using a broad-spectrum antibiotic?

yes.

What are the positive attributes of topical antibiotics?

Applied on skin; low side effects but limited use.

What are the positive/ negatives attributes of oral antibiotics?

Convenient but takes longer to reach peak levels.

What are the advantages of intravenous antibiotics?

Concentration peaks very fast and gradually decreases.

what are the positive / negative atributes of intramuscular antibiotics

takes longer for concentration to reach its peak

List 3 examples of how the use of antibiotics cause a patient harmful side effects.

Toxicity to organs, allergic reactions, disruption of normal microbiota.

How can microbes become resistant to antibiotics? list 5 mechanisms of resistance

1. Enzyme destroys or deactivates the drug. 2. Prevent drug entry. 3. Alter drug target. 4. Pump drug out of cell. 5. Bypass metabolic pathway.

How can we slow down the development of antibiotic resistance?

Finishing prescriptions, using drugs only when needed, combining therapies, and preventing infections through hygiene and vaccination.

What is symbiosis?

A relationship between organisms.

What is mutualism?

A relationship where both organisms benefit.

What is commensalism?

A relationship where one organism benefits and the other is unaffected.

What is parasitism?

A relationship where one organism benefits and the other is harmed.

What are normal microbiota? where do they live?

Microorganisms that live on/in the body without causing disease.

How can normal microbiota become opportunistic pathogens?

By moving to a new location, when the immune system is suppressed, or when disrupted by antibiotics.

What are reservoirs of infection?

Sites where pathogens are maintained and can infect new hosts.

What are zoonoses?

Animal diseases transmissible to humans.

Give an example of a helminthic zoonosis.

Tapeworms in animals.

Give an example of a protozoan zoonosis.

Malaria from mosquitoes.

Give an example of a fungal zoonosis.

Ringworm from cats.

Give an example of a bacterial zoonosis.

Anthrax from cattle.

Give an example of a viral zoonosis.

Rabies from dogs.

What is a human carrier?

Infected individuals who spread disease without symptoms.

What are nonliving reservoirs?

Soil, water, and food.

What is contamination?

The presence of microbes on a surface or object.

What is infection?

Invasion and growth of microbes in the body.

What are portals of entry?

Routes through which pathogens enter the body. (mouth, skin, etc.)

What is virulent?

Highly infectious or harmful.

What is avirulent?

Not harmful.

What does morbidity mean?

Rate of disease occurrence.

What are signs of disease?

Observable/measurable evidence of disease.

What are symptoms?

Subjective feelings of illness.

What is a syndrome?

A group of signs/symptoms characteristic of a disease.

What is etiology?

The study or cause of disease.

How do microbes attach to hosts?

Using adhesion factors like fimbriae, pili, or surface proteins.

What are the types of diseases?

1. Heredity. 2. Congenital. 3. Degenerative. 4. Endocrine. 5. Immunological. 6. Idiopathic. 7. Infectious. 8. Nutritional. 9. Neoplastic. 10. Iatrogenic. 11. Nosocomial.

Heredity

errors in DNA for parents

congenital 

defects present at birth

degenerative

results from aging

endocrine

excess or deficient hormones

immunological

defective immune response

idiopathic

cause unknown

infectious

caused by infectious agent

nutritional

result from lack of nutrients

neoplastic

abnormal cell growth

latrogenic

caused by medical treatment

nosocomial

acquired in health setting

What are the three categories of virulence factors?

Adhesion factors, extracellular enzymes, toxins or antiphagocytic factors.

What happens during the incubation stage of disease?

No symptoms; the pathogen is multiplying.

What occurs during the prodromal stage?

Mild symptoms begin.

What are the characteristics of the illness stage?

Most severe signs/symptoms.

What happens during the decline stage?

Symptoms subside; the immune response wins.

What occurs during convalescence?

Recovery and repair of tissues.

What are portals of exit?

Routes through which pathogens leave the body. ex. nose mouth feces urine skin flakes blood etc.

What is direct contact transmission?

Person-to-person contact such as touching or kissing.

What is indirect contact transmission?

Transmission through contaminated objects, also known as fomites.

What is droplet transmission?

Transmission via mucus droplets from sneezing or coughing.

What are fomites?

Contaminated nonliving objects.

What is vehicle transmission?

Transmission via air, water, food, or bodily fluids.

What is waterborne transmission?

Transmission through contaminated water.

What is airborne transmission?

Transmission via dust or droplets in the air.

What is bodily fluid transmission?

Transmission through saliva, semen, blood, etc.

What are biological vectors?

Animals, especially arthropods, that transmit pathogens. ex. mosquitos

What is an asymptomatic?

A disease without symptoms.

What is a latent?

A disease that appears long after exposure.

What is an acute?

symptoms and course of disease run quickly

What is a contagious?

An infection/disease that is easily spread.

What is a noncommunicable disease?

A disease from opportunistic infection.

What is a chronic?

A disease with mild symptoms, slow and long-lasting progression.

What is a systemic infection?

A widespread infection.

What is a focal infection?

An infection that serves as a source of pathogens for other body sites.

What is a communicable infection?

An infection transmitted from one host to another.