HIỆU QUẢ IN VITRO PHỐI HỢP COLISTIN VỚI MINOCYCLINE VÀ COLISTIN VỚI DOXYCYCLINE TRÊN VI KHUẨN ACINETOBACTER BAUMANNII ĐA KHÁNG

Abstract

Background: Currently Multi-drug resistant (MDR) A. baumannii is one of leading causes of nosocomial infections and antimicrobial resistant incidence is increasing. Colistin is currently assumed as a last resort for treatment, however it causes many nephrotoxic and neurotoxic effects. Therefore, antibiotic combination therapy is recommended for clinical use to help reduce colistin toxicity and MIC of the combination antibiotic, increasing the ability to eradicate bacteria. Objective: To evaluate the in vitro efficacy of antibiotic combination between colistin with minocycline and colistin with doxycycline against MDR A. baumannii. Research method: 96 strains of MDR A. baumannii were collected from the University Medical Center - Ho Chi Minh City from 01/2021-06/2021. Then, antibiotic combination test colistin with minocycline and colistin with doxycycline was performed by the checkerboard microdilution method and determined the FICI index to evaluate effectiveness of the antibiotic combination. Results: Colistin was still effective in vitro against MDR A. baumannii with resistance rate of 4.2% and MIC90 = 2 mg/L. The combination of colistin with minocycline and colistin with doxycycline increased the effectiveness of each other (synergistically or additively) by 94.8% and 96.9% respectively. The combination of colistin concentrations ≤ 2 mg/L significantly reduced the MIC from resistant to sensitive or intermediate of minocycline (96.4%) and doxycycline (35.5%). Conclusion: colistin is still in vitro effecticacy against MDR A. baumannii. The combination of colistin with minocycline and colistin with doxycycline increases the mutual effect at a high rate on MDR A. baumannii.