clinical impact of antibiotic resistance Flashcards
do not give antibiotics when _____
they are not necessary
4 steps in abx resistance development
1 - lots of germs; a few are resistant
2 - abx kill bill bad and good bateria protecting body from infection
3 - drug resistant bacteria are now allowed to grow and take over
4 - some bacteria give their drug resistance to other bacteria, causing increased issues
why is abx resistance such a big problem currently?
- lots of microbes
- short replication time
- mobile resistance
- use and misuse of abx and pressure from patient to treat
- high [ ] and exchange in hospitals
- little new drug development
according to CDC
2 URGENT threats?
3 serious threats?
urgent = c. dificile and CRE (carbapenem resistant enterobacteriaceae)
serious =
MDR acinetobacter
ESBLs (extended spectrum B-lactamase producing enterobacteriaceae)
MRSA (methicillin resistant staph aureus)
c dif causes
abx related diarrhea
second line agents are often….
more toxic
nosocomial infections
- def?
- characteristics?
hospital acquired rather than community acquired (not incubating at time of admission and develops 48 hours after admission)
or
healthcare associated - can be d/t long term care, dialysis, infusion, home wound care
multidrug resistant pathogen (MDR)
resistance or decreased susceptibility to >3 antimicrobials
MDR pseudomonas aeruginosa
not susceptible to at least 1 agent in 3 different abx classes (of the following 5)
- cephalosporins (cef-)
- B-lactam or B-lactamase inhibitors
- carbapenems
- fluoroquinolones
- aminoglycosides
2 cephalosporins
cefepime
ceftazidime
a B lactam? and a B-lactamase inhibitor?
piperacillin
tazobactam
3 carbapenems
imipenem
meropenem
doripenem
2 fluoroquinolones
ciprofloxacin
levofloxacin
3 aminoglycosides
gentamicin
tobramycin
amikacin
what causes central line-associated bloodstream infections?
MRSA (methicillin resistant staph aureus)
what causes catheter associated UTIs?
ESBL e. coli
what causes ventilator associated pneumonia?
MDR gram negatives (pseudomonas aeruginosa)
or
MRSA
what causes abx associated diarrhea?
c. dificile
- fever, watery diarrhea, abdominal pain and leukocytosis
ESBL producing organisms
extended spectrum B lactamase producing enterobacteriaceae
a serious threat
klebsiella and e. coli commonly show esbl organisms; only gram negatives
narrowed zone of abx clearance on culture
what color is gram negative stain?
pink
what is esbl?
extended spectrum b-lactamase
enzyme that confers resistance to penicillins, cephalosporins, and aztreonam (monobactam)
it hydrolyzes B-lactam ring (abx cant get in) and is plasmid mediated
gram negatives only
ESBL and CRE are found only in ________
gram negative bacteria
e coli and klebsiela
esbl restricts treatment to ______
carbapenems
CRE
carbapenem resistant enterobacteriaceae
e coli or kelbsiella that produce both B-lactamase (ESBL) and carbapenemase!
an URGENT threat
carbapenemase enzymes confer resistance to all B-lactam drugs (penicillins, cephalosporins, monobactam, and carbapenems)
gram negatives only
how do you treat CRE?
very limited options….colistin (has neuro and nephrotoxicity)
c dificle characteristics
gram positive spore forming bacillus
produces toxins A and B that leads to diarrhea and colitis
resistant to purell (alcohol antiseptics) –> MUST wash hands
NAP1 c dificile strain
hypervirulent strain–> increased toxin production
more severe, resistant to therapy, increased relapse
c dif can cause what bad conditions?
pseudomembranous colitis = diarrhea and pseudomembranes (thick colonic wall)
fulminant colitis = fever, diarrhea, severe abd pain, hypotension/lactic acidosis, leukocytosis >40k wbc, toxic megacolon, bowel perforation
toxins A and B are produced by
c dificile
how to treat c dif associated colitis
stop abx
avoid anti-motility (loperamide) agents
correct electrolyte and fluid losses
therapy with metronidazole or vancomycin
or fecal transplant
surgery for perforations
mainstay of infection prevention control is
contact prevention
