in vitro pharmacokinetics of ll-37 and oncorhyncin ii combination against acinetobacter baumannii

Background: multidrug-resistant (mdr) acinetobacter baumannii is one of the most common nosocomial pathogens. antimicrobial peptides (amps) have been introduced as a viable alternative to antibiotics in the treatment of mdr pathogens.objectives: this study was designed to assess the in vitro pharmacokinetics of the combination of two potent amps, ll-37 and on-corhyncin ii, against a. baumannii (atcc19606).methods: the synthesized genes of oncorhyncin ii and ll-37 were introduced into escherichia coli bl21 as the expression host. the minimum inhibitory concentration (mic), time-kills, and growth kinetics of these peptides were used to evaluate their antimicro-bial eÿciencies against a. baumannii (atcc19606).results: ll-37 and oncorhyncin ii recombinant peptides showed mic of 30.6 and 95.87 µg/ml against a. baumannii, respectively. additive action was confirmed by combining the generated amps at the checkerboard approach. the combination of ll-37 and oncorhyncin ii at 2 × mic resulted in a rapid drop in log10 cfu/ml of a. baumannii in the time-kill and growth kinetic findings studies.conclusions: the combination of the produced ll-37 and oncorhyncin ii synergizes the bioactivity of the individual peptides. therefore, these peptides or their combinations might function as novel antibiotics and be used to develop and produce new an-timicrobial drugs for the treatment of infections caused by a. baumannii.