Synergistic efficacy of phages along with vancomycin for eradication of vancomycin-resistant biofilms.

BACKGROUND

The upsurge of antibiotic resistance is a significant challenge to public health, and the dry pipeline of new antibiotics has prompted the discovery of alternative treatment approaches. () isolates are often multidrug-resistant, posing challenges to antibiotic therapy. Bacteriophage therapy is being explored as an alternative method to treat the growing population of antibiotic-resistant infections. Nevertheless, many inherent limitations of phages diminish their therapeutic utility, notably the restricted host range and quick development of mutants. The specific types and quantities of bacteriophages and antibiotics may be crucial in generating the optimal phage-antibiotic synergy.

AIM

To optimize the doses, order, and timing to optimize the synergy of phages and vancomycin on different bacteria states.

METHODS

A volume of 180 μL of bacteria in the logarithmic growth phase, with a concentration of approximately 1 × 10 colony forming units (CFUs)/mL, was introduced onto a microtitre plate. Subsequently, 20 μL of phage suspension (1 × 10 PFUs/mL), vancomycin (16 µg/mL), or a combination of both was introduced into the designated wells in the specified sequence and incubated at 37 °C for 48 hours. The number of live bacteria was counted at different time points using standardized CFU counting protocols.

RESULTS

The biofilm model demonstrated that combining phages with vancomycin can eradicate the biofilm. Sequential therapy, involving phage application 8 hours before the antibiotic at a concentration of 10 PFUs/mL, proved the most efficient in eliminating the biofilms and killing the planktonic form of

CONCLUSION

The combination of phage ɸEFP01 at a higher concentration with a subinhibitory concentration of vancomycin yields a synergistic antibacterial outcome on strain resistant to vancomycin.