Exam one: L5-L8

Question 1

L5: what is the definition of epidemiology?

Answer 1

It is the study of disease and populations of factors that determine its occurrence overtime

Question 2

L5: what is the historical origin of epidemiology?

Answer 2

John Snow identified the cause of the London epidemic because he believed that sewage and water could contaminate water. Snow removed the pump eliminated in the area 

Question 3

L5: what are the roles and applications of epidemiology in public health?

Answer 3

It studies the etiology of disease to determine positive factors for assist, and understanding pathogenicity, it identifies describes and determines infection, patterns and disease and populations. It assists in the development of health, initiatives and prevention.

Question 4

L5: what is an agent? What are its characteristics and what is the intervention for it?

Answer 4

An agent is a microorganism that causes disease if characteristics are variance, dose, toxicity, and living conditions, the intervention is to control/eliminate infection at its source

Question 5

L5: what is a host? What are its characteristics and what is the intervention for it?

Answer 5

A host is the thing that gets a disease. It depends on exposure/behavior, susceptibility and response, intervention, for it is treat infection immunize, and behavior modification 

Question 6

L5: what is an environment? What are its characteristics and what its interventions

Answer 6

An environment is backwards that affect the agent and exposure opportunities. Characteristics depend on place insects/biological factors and socioeconomic patterns, it’s interventions or sanitation water, prevention, services, and bug pillows.

Question 7

L5: what is the reservoir?

Answer 7

Is an environment where infectious agent lives and multiplies

Question 8

L7: What are the different B-lactams and common ending?

Answer 8

cilin, cef/ceph, penem, cefiderocol

Question 9

L7: What are the ways that a bacteria resists B-lactams?

Answer 9

By using beta-lactamases, mutating PBPs, efflux pumps, decreasing membrane permeability

Question 10

L7: How do we combat B-lactamases and which bacteria make B-lactamases?

Answer 10

We use combination therapy with B-lactamases, a bacteria that makes B-lactamase is enterococcus and acinetobacter

Question 11

L7: What bacteria mutates their PBPs and how does it work?

Answer 11

MRSA mutates its PBP by acquiring mecA which encodes for PBP2a which decreases affinity for common B-lactams

Question 12

L7: What drug resistant bacteria uses efflux pumps and decreased membrane permeability as a defense?

Answer 12

Pseudomas Aeruginosa

Question 13

L7: What is the most common glycopeptide and what class of Ab is it?

Answer 13

Vancomycin, it is a cell-wall inhibitor

Question 14

L7: What does vancomycin do?

Answer 14

It binds D-ala D-ala to block Tpase activity

Question 15

L7: What does vancomycin resistance look like? And what does it?

Answer 15

VR enterococcus, it mutated D-ala into D-lac so that vancomycin does not recognize it anymore

Question 16

L7: What are DNA targeting antibiotics called? And what do they do? What do the drugs end with?

Answer 16

Fluoroquinolones, interfere with topoisomerase t2 to cause double stranded breaks. Drugs end in floxacin

Question 17

L7: What is a common resistance mechanism against flouroquinolones?

Answer 17

Mutating topoisomerase and gyrase, efflux pumps and permeability barriers

Question 18

L7: What are the ribosomal inhibitors and where do they act?

Answer 18

A site: tetracycline and aminoglycosides
B site: oxazolidinones
C site: macrolides/lincosamides

Question 19

L7: What do nitromidazoles do and what is unique about them?

Answer 19

nitromidazole is a prodrug that when inside an anaerobic cell, makes extremely reactive nitroso intermediates that cause ds breaks in DNA

Question 20

L7: What does rifampin do and what is it good for?

Answer 20

Rifampin blocks RNA polymerase to prohibit translation, it is commonly used in combination bc resistance is easily acquired and it can penetrate osteoblasts and biofilms

Question 21

L7: What do sulfonamides do? What bacteria has intrinsic resistance?

Answer 21

Sulfonamides block the folate synthesis pathway, altering DNA synthesis. Enterococcus has intrinsic resistance because it can take up folate from the environment.

Question 22

L7: What do polymyxins do?

Answer 22

Polymyxins act in G(-) cells to disrupt the outer membrane with hydrophillic cationic ring and hydrophobic tail.

Question 23

L7: What is the good polymyxin and which is the bad one?

Answer 23

pmB is good, in Neosporin
pmA is bad, very toxic and should be used as a last resort.

Question 24

L8: When testing antibiotic susceptibility, which genes do we look for in VRE, MRSA, and TB?

Answer 24

VRE: vanA and vanB
MRSA: MecA
Mycobacterium TB: rpoB