Resistance

Question 1

what are the 2 types of resistance?

Answer 1

1. intrinsic
2. acquired

Question 2

what is intrinsic resistance?

Answer 2

already always resistance
don’t have to do anything
just don’t respond

Question 3

what is acquired resistance?

Answer 3

get from somewhere else

Question 4

what are some ways of acquiring resistance?

Answer 4

environment
- pee in lakes
- animals
not finishing a course of antibiotics
taking antibiotics when you don’t need them
skipping doses

Question 5

how are antibiotics tested?

Answer 5

in vitro
1. zone of inhibition
2. micro broth dilution

Question 6

how does zone of inhibition determine antibiotic effectiveness?

Answer 6

bigger zone = more susceptible = more effective

Question 7

how is micro-broth dilution used to determine antibiotic effectiveness?

Answer 7

minimum inhibitory concentration
smallest amount of antibiotic needed for bacteria to respond

Question 8

what are the 4 mechanisms of resistance?

Answer 8

1.efflux pump
2. reduced permeability
3. enzymatic inactivation
3. altered binding site

Question 9

what are some examples of enzymes produced by bacteria as a resistance mechanism?

Answer 9

penicillinases
cephalosporinases
carbapenemenases

Question 10

what do penicillinases act on?

Answer 10

penicillins

Question 11

what do cephalosporinases act on?

Answer 11

penicillins
cephalosporins

Question 12

what do carbapenemenases act on?

Answer 12

penicillins
cephalosporins
carbapenems

Question 13

what are the 3 ways that bacteria share resistance?

Answer 13

1. conjugation
2. transformation
3. transduction

Question 14

how is resistance shared by conjugation?

Answer 14

bacteria form a bridge between each other
transfer plasmid by direct contact

Question 15

how is resistance shared by transformation?

Answer 15

pick up free DNA or DNA plasmids from environment

Question 16

how is resistance shared by transduction?

Answer 16

bacteriophages carrying resistant mutations attack bacteria

Question 17

what is a bacteriophage?

Answer 17

virus that attacks bacteria

Question 18

what are the 3 gram POSITIVE resistant organisms?

Answer 18

1. MRSA
2. VRE
3. C. diff

Question 19

what type of bacteria is VRE?

Answer 19

gram positive cocci

Question 20

what type of bacteria is C. diff?

Answer 20

gram positive bacilli

Question 21

what are the 2 gram NEGATIVE resistant organisms?

Answer 21

1. ESBL
2. CROs

Question 22

. aureus is a common colonizer of the _____________

Answer 22

skin
nose
perineum

Question 23

S. aureus is one of the most common causes of __________

Answer 23

SSIs
bacteremia
endocarditis
pneumonia
wound infections

Question 24

S. aureus is the most __________

Answer 24

virulent

Question 25

what are the 2 types of S. aureus?

Answer 25

1. MSSA 2. MRSA

Question 26

what is the only treatment for MRSA?

Answer 26

vancomycin

Question 27

what is the MRSA resistant mechanism?

Answer 27

S. aureus cell wall made up of penicillin binding protein-2 MecA resistant gene changes PBP2 to PB2a prevents beta-lactam antibiotics from binding

Question 28

how do we screen for MRSA?

Answer 28

swab nose and butt

Question 29

what precautions are indicated for MRSA?

Answer 29

contact

Question 30

what is the most effective way to prevent spread of MRSA?

Answer 30

wash hands

Question 31

what are the 2 types of enterococcus?

Answer 31

1. enterococcus faecium 2. enterococcus faecalis

Question 32

enterococcus is a norma colonizer of the _________

Answer 32

gut

Question 33

what are the 2 strains of enterococcus?

Answer 33

1. VSE 2. VRE

Question 34

VRE has a significant amount of ______________, so there are very few options for treatment

Answer 34

intrinsic resistance

Question 35

how do we screen for VRE?

Answer 35

swab butthole

Question 36

what is the most effective way to prevent spread of VRE?

Answer 36

environmental cleaning

Question 37

what is the VRE resistant mechanism?

Answer 37

VanA gene changes D-Ala binding sites to D-Ala-Lac prevents vancomycin from binding

Question 38

__________ is the mot common nosocomial infections

Answer 38

C. diff

Question 39

children _________ don't get C. diff because they ___________

Answer 39

less than 2 years don't have receptors

Question 40

how does C. diff cause infection?

Answer 40

produces highly stable toxic spores

Question 41

is C. diff a normal colonizer?

Answer 41

NO

Question 42

when is C. diff treated?

Answer 42

3+ diarrheal episodes

Question 43

what does C. diff cause?

Answer 43

diarrhea intestinal inflammation ulcerative colitis toxic megacolon

Question 44

what is the most effective way to prevent C. diff spread?

Answer 44

environmental cleaning

Question 45

what are the treatments for C. diff?

Answer 45

vancomycin metronidazole

Question 46

what is the problem with treating C. diff with vancomycin?

Answer 46

increases risk of developing VRE increases risk of re-infection or incomplete eradication of spores

Question 47

what is an alternative therapy for C. diff?

Answer 47

fecal microbial therapy

Question 48

what is fecal microbial therapy?

Answer 48

infuse healthy door stool into C. diff gut

Question 49

what are 2 examples of ESBLs?

Answer 49

1. E. coli 2. klebsiella

Question 50

what is the ESBL mechanism of resistance?

Answer 50

produce enzymes that break down beta lactam ring

Question 51

what beta-lactams are ESBLs resistant to?

Answer 51

penicillins cephalosporins NOT carbapenems

Question 52

what are the ultimate superbugs?

Answer 52

CROs

Question 53

what are the CROs?

Answer 53

any gram negative in gut and resistant to carbapenems

Question 54

how are CROs treated?

Answer 54

last line drugs very broad spectrum beta lactam