Abstract:
Background: Phage therapy is reemerging due to the rise in antimicrobial resistance. Despite
the growing interest in the use of bacteriophage (phage) for the prevention, control and removal
of bacterial biofilms, limited scientific data exist on phage application to serve as dual purposes
of preventing bacterial colonization and removing preformed biofilms on medical implant
surfaces.
Objective: The study objective was to isolate, partially characterize and assess phages as
potential antibiofilm agents to prevent and/or reduce multidrug-resistant (MDR) Pseudomonas
aeruginosa clinical isolate biofilm from medical implant surfaces at Jimma Medical Center
(JMC).
Methods: Seven well identified clinical strains of MDR P. aeruginosa were obtained from
different specimens of various patients at JMC. Specific phages were isolated and characterized
based on standard protocols. The phages were tested for their antibiofilm effects after coating
the phage in preventing colonization as well as for their treatment effects in reducing preformed
biofilms of MDR P. aeruginosa on catheter and endotracheal tube segments.
Results: Two P. aeruginosa specific phages (ΦJHS-PA1139 and ΦSMK-PA1139) were isolated
from JMC compound sewage sources. The phages were partially characterized of being
thermally stable up to 40ºC and viable between pH 4.0 and 11.0. The two phages tested against
six clinical MDR strains of P. aeruginosa showed broad host ranges but not on other tested
bacterial species. Both phages reduced MDR bacterial biofilms during screening step. The
phage-coated segments showed 1.2 log 10 up to 3.2 log 10 inhibition relative to non-coated
segments after 6 h of exposure to microbial load. In both phages, 6 h treatment of the segments
with 10 6 PFU/mL yielded 1.0 log 10 up to 1.6 log 10 reductions for ΦJHS and 1.6 log 10 up to 2.4
log 10 reductions for ΦSMK.
Conclusion: The results of this study suggest that phages in this study have great potential for
the development of surface coating agents for preventing MDR bacterial colonization of medical
implants and biofilm removal agents in implant-associated infections
