Makindo Medical Notes

🦠 Burkholderia cepacia complex (Bcc) is a group of Gram-negative bacteria notorious for causing severe pulmonary disease in patients with cystic fibrosis (CF). It is highly antibiotic-resistant, transmissible between CF patients, and associated with the dreaded “cepacia syndrome” (rapid respiratory decline, sepsis, and high mortality).

📖 About

• Originally known as Pseudomonas cepacia.
• Now classified as the Burkholderia cepacia complex (≥20 related species).
• Primarily problematic in CF and chronic granulomatous disease (CGD) patients.

🧬 Characteristics

• Gram-negative, aerobic bacillus.
• Motile but non-capsulated.
• Can grow on simple culture media; produces distinctive earthy odour.
• Forms smooth or rough colonies on selective media such as Burkholderia cepacia selective agar.

🔥 Virulence Factors

• Secretes proteases, lipases, and cytotoxins that damage airway epithelium.
• Forms biofilms in the CF lung → chronic colonisation.
• Resistant to neutrophil killing → worsens outcomes in CGD.

🌍 Source & Transmission

• Environmental reservoirs: soil, water, hospital disinfectants, contaminated medical devices.
• Highly transmissible between CF patients through close contact or shared environments.
• Outbreaks have occurred in CF clinics and wards ➡️ reason for strict infection-control policies.

⚠️ Pathogenicity

• In CF: chronic infection → progressive decline in lung function and frequent exacerbations.
• Cepacia syndrome: acute, necrotising pneumonia with rapid deterioration, septicemia, and poor prognosis.
• Also causes opportunistic infections: UTIs, septic arthritis, catheter-associated infections in immunocompromised hosts.

🔎 Investigations

• Sputum culture: gold standard in CF patients.
• Gram stain and biochemical ID, but molecular typing (PCR, MALDI-TOF) may be required to differentiate species within the complex.
• Antibiotic susceptibility testing is essential as resistance patterns vary widely.

🛡️ Resistance Profile

• Intrinsic resistance to aminoglycosides, polymyxins, and many β-lactams.
• Resistance due to efflux pumps and β-lactamase enzymes.
• Known for multidrug resistance → therapy is very challenging.

💊 Sensitivities

• Some strains may remain sensitive to:
  • 💊 Meropenem or Imipenem (carbapenems)
  • 💊 Trimethoprim–sulfamethoxazole (Co-trimoxazole)
  • 💊 Ceftazidime, Piperacillin–tazobactam, or Minocycline (strain-dependent)
• Therapy often requires combination regimens based on specialist microbiology advice.

🩺 Management

• 📌 Strict segregation/isolation of infected CF patients to prevent cross-infection (“cepacia rules” in CF clinics).
• Antibiotics guided by culture and sensitivity; prolonged IV courses often needed.
• Multidrug regimens sometimes used to suppress rather than eradicate infection.
• Monitoring: frequent lung function tests, chest imaging, sputum cultures.
• For cepacia syndrome → aggressive IV antibiotics + intensive supportive care (mortality remains high).
• CF patients colonised with B. cepacia are usually excluded from lung transplant programmes in some centres due to poor outcomes.

📚 Exam Tips

• Think of B. cepacia in a CF patient with unexpectedly severe deterioration or poor response to standard Pseudomonas therapy.
• Cepacia syndrome = rapid necrotising pneumonia, bacteremia, and death ➡️ exam favourite.
• Infection control is as important as antibiotic therapy due to transmissibility.