Investigating Bacteriophages Targeting the Opportunistic Pathogen Acinetobacter baumannii

Area of Science:

• Microbiology
• Infectious Diseases
• Bacteriophage Therapy

Background:

• Acinetobacter baumannii is a significant opportunistic pathogen causing nosocomial infections.
• Multi-drug resistance (MDR) in A. baumannii necessitates novel therapeutic strategies.
• Bacteriophages are explored as a potential alternative to conventional antibiotics.

Purpose of the Study:

• To investigate bacteriophages from hospital wastewater for activity against clinical A. baumannii isolates.
• To evaluate the safety and efficacy of a selected bacteriophage, vB_AbaM_PhT2.
• To assess potential synergistic effects with existing antibiotics.

Main Methods:

• Isolation and characterization of bacteriophages from hospital wastewater.
• Host range determination against 150 multidrug-resistant A. baumannii clinical isolates.
• Whole genome sequencing to identify virulence factors and antibiotic resistance genes.
• Endotoxin level assessment and in vitro cytotoxicity assays.
• Cellular protection assays using human brain and bladder cell lines.
• Synergy testing with the antibiotic colistin.

Main Results:

• Bacteriophage vB_AbaM_PhT2 demonstrated a 28% host range against MDR A. baumannii isolates.
• Genome sequencing revealed no known virulence or antibiotic resistance genes; endotoxin levels were below preclinical safety thresholds.
• vB_AbaM_PhT2 protected human cell lines from A. baumannii-induced damage and showed synergy with colistin.

Conclusions:

• Bacteriophage vB_AbaM_PhT2 is a safe and effective candidate for controlling A. baumannii infections.
• This bacteriophage shows potential for development as a surface antimicrobial agent in hospital settings.
• Synergy with colistin suggests a potential role in combination therapy against MDR A. baumannii.