A preliminary study of in vitro and in vivo synergistic effects of ciprofloxacin and D-tyrosine against Pseudomonas aeruginosa isolates

摘要

Purpose: To investigate the synergistic antimicrobial effects of ciprofloxacin and D-tyrosine against drug-resistant bacteria. Method: The antimicrobial effects of ciprofloxacin and D-tyrosine on clinical isolates of multidrug-resistant (MDR) Pseudomonas aeruginosa (P. aeruginosa) no. 3556 were determined in vitro based on time-kill curve, and in vivo in P. aeruginosa-zebrafish infection model. Furthermore, 30 clinical isolates of multidrug-resistant P. aeruginosa were used in vitro to ascertain the synergistic effect of the two agents. Results: Combined use of ciprofloxacin and D-tyrosine produced synergistic effects against the clinical isolate of P. aeruginosa no. 3556 in vitro and in vivo. Synergism occurred in 96.67 % (95 % CI, range 83.33 - 99.41 %) of the clinical isolates, and ciprofloxacin dose was reduced in 90 % (95 % CI, range 74.38 - 96.54 %) of the clinical isolates in vitro. Conclusion: These preliminary results suggest that the combination of ciprofloxacin and D-tyrosine is a promising therapeutic strategy against MDR P. aeruginosa infections.