Clinical Implications of Antimicrobial Resistance Flashcards
What defines a nosocomial infection
- Not incubating at the time of admission
- Develops 48 hours after admission
What defines a multidrug-resistant pathogen?
- Resistance or intermediate susceptibility to > or = to 3 antimicrobials or antimicrobial groups
What classifies a MDR Pseudomonas aeruginosa?
– Non‐susceptibility (e.g., resistant or intermediate) to at least one agent in at least 3 antimicrobial classes of the following 5 classes:
– Cephalosporins (cefepime, ceftazidime)
– β‐lactam/β‐lactamβ‐lactamase inhibitor combination (piperacillin, piperacillin/tazobactam)
– Carbapenems (imipenem, meropenem, doripenem)
– Fluoroquinolones (ciprofloxacin or levofloxacin)
– Aminoglycosides (gentamicin, tobramycin, or amikacin)
Example of a central-line associated bloodstream infection
MRSA
Example of a catheter associated UTI
ESBL E. Coli
What can cause Ventilator-associated pneumonia?
- MDR Gram Negatives like Pseudomonas aeruginosa
- MRSA
EBSL?
Extended spectrum beta lactamases Stops: - Penicillin - Cephalosporins - Aztreonam (Monobactam)
Who do we find ESBL in and what do we worry about?
Found in Gram negative organisms like Klebsiella, E.Coli, Enterobacter, Proteus, Pseudomonas
- Also associated with other antimicrobial resistances like fluoroquinolones, aminoglycosides, TMP-SMX
How do we treat ESBL gram negatives?
Have to use Carbapenems like Imipenem and Ertapenem
So what happens when we get Carbapenem-resistant Enterobacteriaceae?
Urgent CDC issue, we see it with persistent Kelbsiella.
We got to use weird ass antibiotics: Colistin (bad neuro and nephrotoxicity) and another agent like Tigecycline.
What is the Hypervirulent strain of C. Diff?
NAP-1: Increased toxin production
What puts you at risk for C.Diff?
- Hospitalization with antibiotic exposure
- Advanced age ( > 65 years = 10x increased risk)
- Proton pump inhibitors ( 3x increased risk)
- Surgery and chemotherapy
C. iff colitis can present in two ways:
- Pseudomembranous colitis
- Fulminant colitis
Discuss symptoms of pseudomembranous colitis
- Diarrhea + pseudomembranes seen on endoscopy
- Thickened colonic wall
Discuss symptoms of fulminant colitis
- Fever
- Diarrhea (may have ileus)
- Severe abdominal pain and cramping
- Hypotension/lactic acidosis
- Marked leukocytosis-leukemoid (>40K WBC)
- Toxic Megacolon
- Bowel perforation
How do we treat C. Diff?
- Stop antibiotic that is causing the issue
- Avoid anti-motility agents like loperamide
- Correct electrolytes and fluid loss
- GIVE antibiotic therapy: Fidaxomicin (new agent) or give fecal transplant
- Surgery if perforated or about to perforate
Spores are RESISTANT to alcohol, be VERY careful
Risk factors for the gram negative rod Acinetobacter
- Prologed hospitalization
- ICU admission
- Recent surgery
- Recent antibiotics
- Central venous catheters
- Nursing home
How do we treat MDR Aceinetobacter?
Toxic/unconventional treatments
- Colistin (again, nephro and neurotoxic)
- Aminoglycosides (nephro and ototoxicity)
- Sulbactam
Risk factors for Methicillin Resistant Staph Aureus (MRSA)
- Hospitalization in previous 12 months
- Nursing home resident
- Close contact with MRSA patients
- Hemodialysis
- Indwelling intravenous catheters
- Prolonged antimicrobial therapy
- Surgical procedures
How do we treat hospitalized patients with MRSA?
– Vancomycin‐ first line therapy – Daptomycin (not for pneumonia) – Linezolid – Ceftaroline (SSTI) – New agents: oritavancin, telavancin, dalbavancin
How do we treat outpatient with MRSA?
– TMP‐SMX – Clindamycin – Doxycyline – Linezolid – Tedizolid
What disease agents are classified as urgent threats by the CDC due to antibiotic resistance
- C. diff
2. Carbapenem resistant Enterobacteriaceae
What disease agents are classified as serious threats by the CDC due to antibiotic resistance
- Multidrug resistance Actinobacter
- Extended spectrum B-lactamase producing Enterobacteriaceae
- Methicilin resistant Staph aureus
