II. Epidemiology
- Health Care Associated Infections are caused by multidrug resistant organisms in 16% of cases (especially MRSA)
III. Pathophysiology: Factors Affecting Drug Resistance
-
Antibiotic Overuse
- Viral Upper Respiratory Infections
- Agricultural Antibiotic use
- Increasing Incidence of Immunocompromised patients
- Food supply globalization
IV. Mechanisms: Beta-Lactamase
- Beta-Lactams (Penicillins and Cephalosporins) inhibit transpeptidase
- Transpeptidase cross-links peptidoglycan mesh in the synthesis of the Bacterial cell wall
- Beta-Lactams inhibition of Transpeptidase results in lysis and death of the Bacterial cell
- Beta-Lactams are inactivated by the enzyme Beta-Lactamase
- Beta-Lactamase is produced by beta-lactam resistant Bacteria
- Several Antibiotics have since been developed to be resistant to Beta-Lactamase
- Beta-Lactamase Resistant Penicillins include Dicloxacillin and Nafcillin
V. Causes: Emerging Drug Resistance
- Methicillin Resistant Staphylococcus Aureus (MRSA)
- Penicillin Resistant Pneumococcus
- Vancomycin Resistant Enterococcus (VRE)
- Multi-resistant Gram Negative Bacilli
- ESBL-Producing Enterobacteriaceae
- Carbapenem-Resistant Enterobacteriaceae (CRE)
- Carbapenem-Resistant Klebsiella
- AmpC Beta-Lactamase-Producing Enterobacteriaceae (typically respond to Cefepime)
- Enterobacter cloacae
- Klebsiella aerogenes
- Citrobacter freundii
- Pseudomonas aeruginosa resistance
- Nosocomial outbreaks
- Restricted drug use sometimes beneficial
- Multi-Resistant Neisseria Gonorrhea
- Multi-Resistant Tuberculosis
-
Carbapenem-Resistant Acinetobacter Baumannii
- Lung and Wound Infections or colonization
- Treated with high dose Unasyn (>= 6g sulbactam) AND Minocycline, Tigecycline or polymyxin B
- May be sensitive to Cefiderocol
- Stenotrophomonas maltophilia
- Lung and Wound Infections in Immunocompromised patients (esp. Hematologic Malignancy)
- Treated with two of the following: TMP-SMZ, Minocycline, Tigecycline, cifiderocol, Levofloxacin
- Alternatively treated with Ceftazidime-Avibactam AND Aztreonam
VI. Prevention
-
Antibiotic Stewardship
- Limit Antibiotics to cases in which they are absolutely indicated
- Prevent spread
- See Health Care-Associated Infection
- See Personal Protection Equipment
- Practice good Hand Hygiene before and after seeing each paint
- Follow contact precautions for colonized or infected patients
- Consider culturing for nasal MRSA in high risk hospital settings (e.g. ICU) and decolonization with Bactroban of infected patients
- Decolonization
- Chlorhexidine baths daily for Intensive Care unit patients (esp. MRSA, VRE patients)
VII. Resources
- Centers for Disease Control
- Patient Education Tools on appropriate Antibiotic use
-
Patient Education from FamilyDoctor.org
- Antibiotic Resistance
- Antibiotic Indications