Establishment and preliminary application of a rapid pathogen-specific phenotypic antibiotic susceptibility test for Acinetobacter baumannii

Abstract

Objective To establish a rapid phenotypic antibiotic susceptibility testing of Acinetobacter baumannii based on surfactant-propidium monoazide (PMAxx)-qPCR reaction system. Methods The type and optimal concentration of surfactant, exposure time and concentration of PMAxx were optimized successively. The copies of genomic DNA of Acinetobacter baumannii specific discriminant gene (blaOXA-51) was detected by qPCR. The susceptibility of Acinetobacter baumannii to antibiotics was determined by the antibiotic-bacterial co-reaction system. Results The Results indicated that 0.2% sodium lauroylsarcosinate and 20 μmol/L PMAxx after 5 min exposure effectively inhibited the DNA amplification of dead cells but had no effect on that of live cells. The phenotypic antibiotic susceptibility testing model based on this study could quickly (within 2 h) and accurately predict the susceptibility of Acinetobacter baumannii to doxycycline and levofloxacin (P < 0.01), and the reliable susceptibility of cefoperazone/sulbactam was predicted more than 2 h. Conclusion Our phenotypic antibiotic susceptibility test based on the sodium lauroylsarcosinate-PMAxx-qPCR system provides a basis for the treatment of Acinetobacter baumannii within a short time, and guides the clinical precision medication.

Keywords

• acinetobacter baumannii
• rapid pathogen-specific phenotypic antibiotic susceptibility testing
• sodium lauroylsarcosinate
• propidium monoazide
• real-time quantitative pcr
• bacteria-specific identification and quantification genes