Interaction of lytic phage T1245 with antibiotics for enhancement of antibacterial and anti-biofilm efficacy against multidrug-resistant Acinetobacter baumannii

Abstract

Biofilms associated with multidrug-resistant (MDR) Acinetobacter baumannii on medical devices remain a big clinical problem. Antibiotic susceptibility tests were performed with eight commonly employed antibiotics against clinical isolates. The effects of antibiotics in combination with well-characterized lytic phage T1245 were studied to assess their antibacterial and anti-biofilm efficacy. Ceftazidime, colistin, imipenem, and meropenem significantly reduced bacterial density up to approximately 80% when combined with phage T1245, compared with control. Phage T1245 in combination with ceftazidime, colistin, and meropenem at subinhibitory concentrations demonstrated significant reduction in biomass and bacterial viability of 3-day established biofilms, compared with antibiotic alone. In addition, electron microscopy further confirmed the disruption of biofilm structure and cell morphology upon treatment with phage T1245 and antibiotics, including ceftazidime, colistin, and meropenem. Combined treatment of phage T1245 with these antibiotics could be employed for the management of A. baumannii infections and eradication of the bacterial biofilms.

Keywords:

• Acinetobacter baumannii
• multidrug resistance
• bacteriophage
• synergistic effect
• biofilm
• antibiotic

Disclosure statement

No conflict of interest was reported by the authors.

Additional information

Funding

This study was funded by the Thailand Research Fund through the Royal Golden Jubilee PhD Programme (Grant No. PHD/0106/2559) and the National Research Council of Thailand (Grant No. N41A640071).