Acinetobacter Infections: Clinical Overview, Resistance Challenges, and Prevention

Acinetobacter is a genus of Gram-negative, non-fermenting coccobacilli ubiquitous in soil, water, and healthcare environments. While often colonizers, they are significant opportunistic pathogens, particularly in immunocompromised and critically ill patients.

Key Species

Acinetobacter baumannii accounts for ~80% of human infections and is notorious for multidrug resistance (MDR), including carbapenem resistance (CRAB). Other species (A. pittii, A. nosocomialis) are less common but also develop resistance.

Clinical Syndromes

• Ventilator-associated pneumonia (VAP) – Most common manifestation in ICUs.
• Bloodstream infections (BSI) – Often catheter-related; high mortality in septic patients.
• Skin and soft tissue infections – Burn wounds, surgical sites, traumatic injuries.
• Urinary tract infections – Usually catheter-associated.
• Meningitis – Rare, post-neurosurgery or trauma.

Treatment Challenges

MDR A. baumannii often leaves few options: colistin, polymyxin B, tigecycline, aminoglycosides, or newer agents (cefiderocol, sulbactam-durlobactam). Combination therapy is frequently used, but evidence is limited. Susceptibility testing is essential.

Prevention and Control

• Hand hygiene: WHO 5 Moments; alcohol-based hand rub effective against Acinetobacter.
• Contact precautions: Gown/gloves for colonized/infected patients; dedicated equipment.
• Environmental cleaning: Enhanced terminal cleaning with sporicidal agents (e.g., hydrogen peroxide vapor, UV-C) for high-touch surfaces and equipment.
• Antimicrobial stewardship: Restrict broad-spectrum antibiotics; de-escalate based on cultures.
• Device bundle compliance: Central line, ventilator, and urinary catheter bundles reduce entry points.
• Surveillance cultures: Active screening in high-risk units (ICU, burn) during outbreaks.

No vaccine exists. Early recognition, source control, appropriate empiric therapy (guided by local antibiograms), and rigorous infection control are the cornerstones of management.