Abstract
This study was performed to investigate the mechanisms of in vivo acquisition of colistin resistance in A. baumannii during colistin treatment. Three colistin-susceptible/resistant pairs of A. baumannii were recovered from patients who underwent colistin treatment. All of the 6 isolates included in this study shared an identical sequence type (ST), ST375, and they showed identical SmaI-macrorestriction patterns by pulsed-field gel electrophoresis. The individual colistin-resistant isolates harbored distinct mutations in the pmrB gene. Mutations detected in the pmrB gene were Ala227Val, Pro233Ser, and frame shift from Phe26. In matrix-assisted laser desorption ionization-time of flight analysis, colistin-resistant isolates were different from their colistin-susceptible counterparts, and they showed additional distinct peaks at 1852 m/z, 1937 m/z, 1954 m/z, 1975 m/z, 2034 m/z, and 2157 m/z. In vivo selection of colistin-resistant A. baumannii occurred independently in strains of ST357 during colistin treatment, and the strains acquired colistin resistance via mutations in the pmrB gene resulting in modification of lipid A components.
Original language | English |
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Pages (from-to) | 362-366 |
Number of pages | 5 |
Journal | Diagnostic Microbiology and Infectious Disease |
Volume | 79 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2014 Jul |
Bibliographical note
Funding Information:Funding: This study was supported by a grant of the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea ( A120843 ).
All Science Journal Classification (ASJC) codes
- Microbiology (medical)
- Infectious Diseases