Bacteriophages: The promising therapeutic approach for enhancing ciprofloxacin efficacy against bacterial infection

BACKGROUND: The emergence of ciprofloxacin‐resistant bacteria is a serious challenge worldwide, bringing the need to find new approaches to manage this bacterium. Bacteriophages (phages) have been shown inhibitory effects against ciprofloxacin‐resistance bacteria; thus, ciprofloxacin resistance or tolerance may not affect the phage's infection ability. Additionally, researchers used phage‐ciprofloxacin combination therapy for the inhibition of multidrug‐resistant bacteria. RESULTS: The sublethal concentrations of ciprofloxacin could lead to an increase in progeny production. Antibiotic treatments could enhance the release of progeny phages by shortening the lytic cycle and latent period. Thus, sublethal concentrations of antibiotics combined with phages can be used for the management of bacterial infections with high antibiotic resistance. In addition, combination therapy exerts various selection pressures that can mutually decrease phage and antibiotic resistance. Moreover, phage ciprofloxacin could significantly reduce bacterial counts in the biofilm community. Immediate usage of phages after the attachment of bacteria to the surface of the flow cells, before the development of micro‐colonies, could lead to the best effect of phage therapy against bacterial biofilm. Noteworthy, phage should be used before antibiotics usage because this condition may have allowed phage replication to occur first before ciprofloxacin interrupted the bacterial DNA replication process, thereby interfering with the activity of the phages. Furthermore, the phage‐ciprofloxacin combination showed a promising result for the management of Pseudomonas aeruginosa infections in mouse models. Nevertheless, low data are existing about the interaction between phages and ciprofloxacin in combination therapies, especially regarding the emergence of phage‐resistant mutants. Additionally, there is a challenging and important question of how the combined ciprofloxacin with phages can increase antibacterial functions. Therefore, more examinations are required to support the clinical usage of phage‐ciprofloxacin combination therapy.