Infectious Diseases

Question 1

What are the classes of pathogenic microorganisms?

Answer 1

Bacteria, viruses, parasites, fungi, prions

Question 2

What are the eukaryotic pathogens? Prokaryote? Subcellular?

Answer 2

Parasites and Fungi

Bact

Prions and viruses

Question 3

What are the characteristics of fungi?

Answer 3

Eukaryote; thicc carbohydrate cell wall; singlecellular to long, extensive chains

Cause Mycoses (superficial, subcutaneous, systemic)

Question 4

What are the characteristics of parasitic pathogens?

Answer 4

Eukaryotic; multi-formed (from single cell-> multicellular)

Question 5

What are the characteristics of bacteria?

Answer 5

Unicellular; prokaryotic; cell walls; no organelles/nucleus

Question 6

What are the characteristics of prions?

Answer 6

Protein particles without a nucleus

• cause misfolding protein disease
• resistent to inactivation

Question 7

What are the routes of transmission?

Answer 7

• Direct contact
• Contamination
• Airborne
• Exchange of fluids
• Vector (animal/arthropod)

Question 8

How are bacteria differentiated in a lab setting?

Answer 8

Multitude of lab tests including gram stains, catalase, blood agar, etc. to differentiate presence or absence of enzymes, composition of cell wall, etc

Question 9

What is a key characteristic of anaerobic gram + cocci?

Answer 9

Part of normal flora, but can cause infection when spread to a sterile area

Question 10

What are the two types of gram + bacteria?

Answer 10

Cocci and bacili

Question 11

What test can differentiate staph from strep?

Answer 11

Catalase test (staph is + and strep is -)

Question 12

How can staph aureus be diff from other staph infections?

Answer 12

Coagulase (S. aureus = +)

Question 13

What can staph aureus cause?

Answer 13

Superficial lesions, scalded skin syndrome, toxic shock syndrome

-systemic infections can also occur

Question 14

What is an issue with the structure of biofilms?

Answer 14

Increased resistance to antimicrobials

-breakdown can lead to systemic infections

Question 15

What methods can test efficacy of antibiotics on a bacteria?

Answer 15

Broth dilution, antimicrobial gradient, and disc diffusion

Question 16

What antibiotics inhibit protein synthesis?

Answer 16

• aminoglycosides
• chloramphenicol
• macrolides
• streptothricin
• tetracycline

Question 17

What antibiotics inhibit DNA/RNA synthesis?

Answer 17

• Quinolones

- Rifampin

Question 18

What antibiotics interfere with the cell wall?

Answer 18

• Beta-Lactams

- Glycopeptides

Question 19

What ABX inhibits energy metabolism?

Answer 19

• Sulfonamides

- Trimethoprim

Question 20

What are some ways bacteria can resist antibiotics?

Answer 20

Changes of permeability to cell wall

• Efflux of ABX
• Enzymatic modification
• degredation of ABX
• Modification of ABX target

Question 21

What are three sources of gene transport for bacterii?

Answer 21

Conjugation (bacteria sex), transformation (environment), transduction (bacteriophage)

Question 22

What kind of hemolysis is clear and complete lysis of RBC?

Answer 22

Beta-hemolytic

Question 23

What type of hemolysis is partially lysed RBC?

Answer 23

Alpha-hemolytic (green)

Question 24

What type of hemolysis is associated with no hemolytic activity?

Answer 24

Gamma-hemolytic

Question 25

What are ways to test for type of strep infection?

Answer 25

Colony morphology, hemolytic patterns, biochem reactions, serological specificityq

Question 26

What is the most common “strep fever” strain?

Answer 26

Strep pygenes - beta-hemolytic - gram + - “clumped” colony

Question 27

What does strep pneumoniae cause?

Answer 27

Pneumonia, menengitis, etc - A-hemolytic - Optochin sensitive - Gram +

Question 28

What are some gram - cocci that are most clinically foundational?

Answer 28

Neisseria (gonorrhoeae/meningitidis) Moraxella (catarrhalis)

Question 29

T or F: Gram - is festidious and requires a specific medium to grow.

Answer 29

True

Question 30

What are the two most common plates used to diff gram - species?

Answer 30

Blood and chocolate agar

Question 31

What two sub-tests can diff niseria species?

Answer 31

Oxidase and catalase

Question 32

What is the shape of Gram - bacilli?

Answer 32

Shorter, but still rod-like

Question 33

What is a common gram - bacteria that is associated with food poisoning, gastroenteritis, and newborn meningitis

Answer 33

E. Coli

Question 34

What diseases is pseudomonas aeruginosa associated with?

Answer 34

Lung and UTI

Question 35

What is a high risk for gram - bacterial infection?

Answer 35

Hospitalization and catheters (most risk) - recent sx - war wounds - dialysis - mechanical ventilator - decr immune system

Question 36

Where can gram - samples be obtained?

Answer 36

Stool, blood, urine, sputum, lumbar puncture, abscess/lesion culture

Question 37

What decides where a gram - specimen is obtained?

Answer 37

Nature of the symptoms (eg. diarrhea=stool sample)

Question 38

What media should be used for gram -?

Answer 38

Blood or McConkey agar

Question 39

What does a MacConkey agar measure?

Answer 39

Lactose fermentation and it has bile

Question 40

Signs of what immune cell in a culture is indicative of bacterial infection?

Answer 40

Neutrophils

Question 41

What are signs of viral infections in a blood culture?

Answer 41

Elevated leukocyte counts

Question 42

What type of gram bacteria is most common in UTIs?

Answer 42

Gram -