Emerging

Antibiotic Resistance

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Antibiotic Resistance, Antibiotic Resistant Infection, Antimicrobial Resistance, Multidrug-Resistant Organism, Multi-Drug Resistant Bacteria, Beta-Lactamase

  • See Also
  1. Emerging Infections
  2. Nosocomial Pneumonia
  3. Health Care-Associated Infection
  4. Antibiotic Stewardship
  • Epidemiology
  1. Health Care Associated Infections are caused by multidrug resistant organisms in 16% of cases (especially MRSA)
  • Pathophysiology
  • Factors Affecting Drug Resistance
  1. Antibiotic Overuse
    1. Viral Upper Respiratory Infections
    2. Agricultural Antibiotic use
  2. Increasing Incidence of Immunocompromised patients
  3. Food supply globalization
  • Mechanisms
  • Beta-Lactamase
  1. Beta-Lactams (Penicillins and Cephalosporins) inhibit transpeptidase
  2. Transpeptidase cross-links peptidoglycan mesh in the synthesis of the Bacterial cell wall
    1. Beta-Lactams inhibition of Transpeptidase results in lysis and death of the Bacterial cell
  3. Beta-Lactams are inactivated by the enzyme Beta-Lactamase
    1. Beta-Lactamase is produced by beta-lactam resistant Bacteria
  4. Several Antibiotics have since been developed to be resistant to Beta-Lactamase
    1. Beta-Lactamase Resistant Penicillins include Dicloxacillin and Nafcillin
  • Causes
  • Emerging Drug Resistance
  1. Methicillin Resistant Staphylococcus Aureus (MRSA)
  2. Penicillin Resistant Pneumococcus
  3. Vancomycin Resistant Enterococcus (VRE)
  4. Multi-resistant Gram Negative Bacilli
    1. ESBL-Producing Enterobacteriaceae
    2. Carbapenem-Resistant Enterobacteriaceae (CRE)
    3. Carbapenem-Resistant Klebsiella
    4. AmpC Beta-Lactamase-Producing Enterobacteriaceae (typically respond to Cefepime)
      1. Enterobacter cloacae
      2. Klebsiella aerogenes
      3. Citrobacter freundii
    5. Pseudomonas aeruginosa resistance
    6. Nosocomial outbreaks
    7. Restricted drug use sometimes beneficial
  5. Multi-Resistant Neisseria Gonorrhea
  6. Multi-Resistant Tuberculosis
  7. Carbapenem-Resistant Acinetobacter Baumannii
    1. Lung and Wound Infections or colonization
    2. Treated with high dose Unasyn (>= 6g sulbactam) AND Minocycline, Tigecycline or polymyxin B
    3. May be sensitive to Cefiderocol
  8. Stenotrophomonas maltophilia
    1. Lung and Wound Infections in Immunocompromised patients (esp. Hematologic Malignancy)
    2. Treated with two of the following: TMP-SMZ, Minocycline, Tigecycline, cifiderocol, Levofloxacin
    3. Alternatively treated with Ceftazidime-Avibactam AND Aztreonam
  • Prevention
  1. Antibiotic Stewardship
    1. Limit Antibiotics to cases in which they are absolutely indicated
  2. Prevent spread
    1. See Health Care-Associated Infection
    2. See Personal Protection Equipment
    3. Practice good Hand Hygiene before and after seeing each paint
    4. Follow contact precautions for colonized or infected patients
    5. Consider culturing for nasal MRSA in high risk hospital settings (e.g. ICU) and decolonization with Bactroban of infected patients
  3. Decolonization
    1. Chlorhexidine baths daily for Intensive Care unit patients (esp. MRSA, VRE patients)
  • Resources
  1. Centers for Disease Control
    1. Patient Education Tools on appropriate Antibiotic use
      1. http://www.cdc.gov/antibioticresistance/tools.htm
  2. Patient Education from FamilyDoctor.org
    1. Antibiotic Resistance
      1. http://www.familydoctor.org/handouts/659.html
    2. Antibiotic Indications
      1. http://www.familydoctor.org/handouts/680.html
  • Reference
  1. (1995) Lecture: M Osterholm, MD, Minneapolis, MN
  2. Hooton (2001) Am Fam Physician 63(6):1087-6 [PubMed]
  3. Hsu (2014) Am Fam Physician 90(6): 377-82 [PubMed]
  4. Sensakovic (2001) Med Clin North Am 85:115-23 [PubMed]
  5. Tamma (2023) Clin Infect Dis +PMID: 37463564 [PubMed]