Survey of pharmacological synergism of mellitin with antibiotics against multi-drug resistant P. aeruginosa and A. baummanni

Background and aim: In this study the synergism of mellitin and some antibiotics including colistin, ceftazidim, doxycycline and doripenem on MDR A. baumanni and P. aeruginosa isolates were evaluated.Materials and methods: At first 50 isolates of P. aeruginosa and 50 A. baumanni isolates from burn patients were identified and collected. The bee‟s venom was purchased and its mellitin fractionized by reverse HPLC. Further mellitin confirmation was done by SDS-PAGE method.124Based on CLSI the sensitivity or resistant (AST) to selected antibiotics was done by disk diffusion method and minimum inhibitory concentration (MIC) of each antibiotics alone and in combination to mellitin were determined by microdilution method. In continuous, the cytotoxicity of mellitin against HEK 293 was determined by MTT test for synergism‟s MIC concentration.Results: Mellitin confirmation was done by SDS-PAGE after detection of a 2.824Kd band in front of standard mellitin. Based on the AST, of 50 P. aeruginosa isolates the most resistant rate was to gentamicin 93% (28/ 50) and the least resistant to piperacillin-tazobactam 23% (7/ 50).Also, of 50 A. baumanni the most resistant to ceftazidim 100% and the least was to doxycycline 40%.The most synergism was seen between mellitin and doripenem among MDR P. aeruginosa isolates which was 0.8-6.4μg/mL. The cytotoxicity of mellitin on HEK 293 cells in its synergism MIC dose was 43 to 96.4%.Conclusion: In the recent study, the most synergy effect was seen between mellitin and doripenem which shows high decreasing from 102.4 to 0.4 μg/mL This result was in accordance of Issam Al-Ani and colleagues in Heidelberg‟s university.

کلیدواژه ها:

mellitin ، antibiotic ، synergism