Mối liên quan giữa mức độ kháng carbapenem và sự xuất hiện gen mã hóa carbapenemase của các chủng Acinetobacter baumannii phân lập tại một số bệnh viện

Abstract

In addition to virulence factors, antibiotic resistance has helped strains of Acinetobacter baumannii become one of the most common agents of hospital-acquired infections. In A. baumannii, carbapenem resistance is mainly mediated by carbapenemase. In this study, 144 strains of A. baumannii isolated from 9 hospitals in representing 3 regions of Vietnam were studied to detect the minimum inhibitory concentration (MIC) and find an association between carbapenem resistance levels and the appearance of some carbapenemase coding genes. Results: more than 70.8% of the isolated were resistant to 7/9 antibiotics tested; 83.3% strains were resistant to 3 carbapenem antibiotics with MIC50, and MIC90 values were 32-64 µg/ml and ≥64 µg/ml, respectively; 100% strains were susceptible to colistin (MIC50=0.25 µg/ml and MIC90=0.5 µg/ml). Strains with only blaOXA-51 showed much lower rates of antibiotic resistance and MIC than those with ≥2 carbapenemase genes (p<0.01). 100% strains carrying blaOXA-23 and blaNDM-1 were resistant to carbapenem with very high MIC values. Conclusion: there is an association between carbapenem resistance and the appearance of gene blaOXA-23 and blaNDM-1. Colistin is the last resort for the treatment of multidrug-resistant A. baumannii.