Makindo Medical Notes

Related Subjects: Asthma |Acute Severe Asthma |Exacerbation of COPD |Pulmonary Embolism |Cardiogenic Pulmonary Oedema |Pneumothorax |Tension Pneumothorax |Respiratory (Chest) infections Pneumonia |Fat embolism |Hyperventilation Syndrome |ARDS |Respiratory Failure |Diabetic Ketoacidosis

⚠️ Klebsiella pneumoniae is a major cause of hospital-acquired pneumonia. Rising antibiotic resistance, including carbapenem resistance, makes it a critical healthcare challenge.

📖 About

• Originally called Friedländer's bacillus, part of the Enterobacteriaceae family.
• Lactose-fermenting Gram-negative bacillus 🦠.
• Large polysaccharide capsule is the main virulence factor → protects against phagocytosis and immune clearance.
• Capsule-deficient strains are far less virulent.

🌍 Source

• Normal flora in the GI tract and oropharynx.
• Opportunistic pathogen in hospitals → respiratory & urinary tract infections.
• High virulence and resistance → major concern in nosocomial outbreaks.

🔬 Characteristics

• Gram-negative, encapsulated rods.
• Aerobic / facultative anaerobe.
• Ferments glucose & lactose → pink colonies on MacConkey agar 🎨.
• Oxidase-negative, catalase-positive, reduces nitrates to nitrites.

🩺 Clinical Presentation

• Respiratory: Severe lobar pneumonia, currant jelly sputum (thick, bloody), dyspnoea, fever, sepsis.
• High-risk groups: 🍺 alcoholics, 🩸 diabetics, ventilated patients, chronic lung disease.
• May show bulging fissure sign on CXR (due to lobar expansion).

⚠️ Pathogenicity

• Pneumonia: Classically affects debilitated or alcoholic patients → necrotising, cavitating infection.
• UTIs: Associated with long-term catheterisation or diabetes.
• Pyogenic Liver Abscess: Invasive syndrome with bacteremia, especially in diabetics or immunocompromised.

🧪 Resistance

• ESBLs: Extended-spectrum beta-lactamases → resistant to many penicillins & cephalosporins.
• Carbapenem resistance: Carbapenemase-producing strains (KPC, NDM) → highly resistant, limited options.
• Multidrug resistance to fluoroquinolones, aminoglycosides, etc. is increasingly common.

💊 Management

• Supportive care: Oxygen, airway management, chest physiotherapy, HDU/ICU support if severe.
• Antibiotics: Guided by microbiology & sensitivity results:
  • Non-resistant strains → 3rd-gen cephalosporins (ceftriaxone), fluoroquinolones, aminoglycosides.
  • ESBL-producing strains → carbapenems (meropenem, imipenem) 🚑.
  • Carbapenem-resistant strains → combination regimens: colistin, tigecycline, fosfomycin, ± ceftazidime-avibactam.
• Prognosis: Mortality remains high (30–50%), especially in elderly, diabetic, or immunosuppressed patients.