Impact of Tigecycline's MIC in the Outcome of Critically Ill Patients with Carbapenemase-Producing <i>Klebsiella pneumoniae</i> Bacteraemia Treated with Tigecycline Monotherapy-Validation of 2019's EUCAST Proposed Breakpoint Changes

• Main Authors: Matthaios Papadimitriou-Olivgeris (Author), Christina Bartzavali (Author), Alexandra Nikolopoulou (Author), Fevronia Kolonitsiou (Author), Virginia Mplani (Author), Iris Spiliopoulou (Author), Myrto Christofidou (Author), Fotini Fligou (Author), Markos Marangos (Author)
• Format: Book
• Published: MDPI AG, 2020-11-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Background: Tigecycline is a therapeutic option for carbapenemase-producing <i>Klebsiella pneumoniae</i> (CP-Kp). Our aim was to evaluate the impact of the tigecycline's minimum inhibitory concentration (MIC) in the outcome of patients with CP-Kp bacteraemia treated with tigecycline monotherapy. Methods: Patients with monomicrobial bacteraemia due to CP-Kp that received appropriate targeted monotherapy or no appropriate treatment were included. Primary outcome was 30-day mortality. MICs of meropenem, tigecycline, and ceftazidime/avibactam were determined by Etest, whereas for colistin, the broth microdilution method was applied. PCR for <i>bla</i>_KPC, <i>bla</i>_VIM, <i>bla</i>_NDM, and <i>bla</i>_OXA genes was applied. Results: Among 302 CP-Kp bacteraemias, 32 isolates (10.6%) showed MICs of tigecycline ≤ 0.5 mg/L, whereas 177 (58.6%) showed MICs that were 0.75-2 mg/L. Colistin and aminoglycoside susceptibility was observed in 43.0% and 23.8% of isolates, respectively. The majority of isolates carried <i>bla</i>_KPC (249; 82.5%), followed by <i>bla</i>_VIM (26; 8.6%), both <i>bla</i>_KPC and <i>bla</i>_VIM (16; 5.3%), and <i>bla</i>_NDM (11; 3.6%). Fifteen patients with tigecycline MIC ≤ 0.5 mg/L and 55 with MIC 0.75-2 mg/L were treated with tigecycline monotherapy; 30-day mortality was 20.0% and 50.9%, respectively (<i>p</i> = 0.042). Mortality of 150 patients that received other antimicrobials was 24.7%; among 82 patients that received no appropriate treatment, mortality was 39.0%. No difference in 30-day mortality was observed between patients that received tigecycline (MIC ≤ 0.5 mg/L) or other antimicrobials. Conclusion: Tigecycline monotherapy was as efficacious as other antimicrobials in the treatment of bloodstream infections due to CP-Kp isolates with a tigecycline's MIC ≤ 0.5 mg/L.

Item Description

10.3390/antibiotics9110828
2079-6382