introduction

Question 1

How do we categorize bacterial pathogens?

Answer 1

largely by shape and gram staining

Question 2

gram positive shape

Answer 2

mostly cocci and few rods

Question 3

gram negative shape

Answer 3

mostly rods and few cocci

Question 4

if the bacteria contains LPS

Answer 4

gram negative

LPS= endotoxin

Question 5

divergent antibiotic susceptibility

Answer 5

there is different philic and phobic properties of the wall; gram negative are hydrophillc while gram positive have a hydrophobic

Question 6

gram stain for positive and negative

Answer 6

gram positive- blue/purple

gram negative- red/pink

Question 7

the most important atypical bacteria

Answer 7

Mycobacterium tuberculosis

the cell wall is a waxy lipid mycolic acid

Question 8

gold standard for detection of pathogens

Answer 8

culture

Question 9

Anaerobic bacteria are bacteria that do not live or grow when oxygen is present. In humans, these bacteria are most commonly found in the

Answer 9

gastrointestinal tract

Question 10

what do we see in a slide of patient with chickenpox

Answer 10

multinucleated giant cell – epithelial cell containing numerous nuclei, viral inclusions give nuclei a homogenous, glassy appearance

Question 11

Antibiotics act at 4 major sites in the bacterium

Answer 11

1. Cell wall
2. Cell membrane
3. Sites of protein synthesis
4. Sites of nucleic acid synthesis

Question 12

Bacteriostatic-

Answer 12

inhibits growth of bacteria

Question 13

Bactericidal-

Answer 13

> 99.9% killing (3 logs) of bacteria at 24 hrs

Question 14

drug concentration at which visible growth of organism is inhibited in test tube

Answer 14

MIC- minimum inhibitory concentration of drug

Question 15

drug concentration at which the subculture of the MIC tube shows no growth -99.9% of original inoculum of organisms is killed

Answer 15

MBC- minimum bactericidal concentration