Purpose: Tigecycline has been considered as one therapeutic choice for carbapenem resistant Klebsiella pneumoniae (CRKP). Once the CRKP has resistance to tigecycline, the treatment option is more difficult. We investigated the clinical and microbiological characteristics of dual tigecycline and carbapenem resistant Klebsiella pneumoniae (TR-CR KP) in Taiwan. Methods: We collected 11 TR-CR K.P isolates from 6 different hospitals in Taiwan in 2012. The tests performed included antibiotic susceptibility tests; detection of carbapenemase, extended-spectrum β-lactamases (ESBL), and AmpC β-lactamases genes; outer membrane porin profiles; gene sequence of ramR, which is a repressor of efflux pump and genetic relationship with pulsed-field gel electrophoresis and multilocus sequence type. K. Pneumoniae isolates with resistance to tigecycline were identified by E-test using the US Food and Drug Administration criteria. Clinical data of the patient was recorded retrospectively. Results: Of 11 isolates, 8 caused urinary tract infection, 2 caused pneumonia and one was peritonitis. The MIC50 and MIC90 of tigecycline were 8 and 16 mg/L, respectively. Two isolates had KPC-2 detection; three had IMP-8 detection; 7 isolates had extended spectrum β-lactamases and/or DHA-1 genes. No major cluster of isolates was found by PFGE. The mutation of ramR was found in 7 isolates including, the mutation over A→V (19) in 5 isolates. Overall 28-day mortality was 45.5% (5/11) in patients with . Conclusions: The high mortality rate of patients with TR-CR KP is an emerging critical problem. The mutation of ramR over the A→V (19) is associated with increased tigecycline resistance. Current data showed no clonal spread of single lineage of TR-CR KP in Taiwan. Continuous monitor of the situation of tigecycline resistant isolate is necessary.
Date:
2015-04
Relation:
Journal of Microbiology, Immunology and Infection. 2015 Apr;48(2, Suppl.1):S175-S176.
