Investigation of Plasmid-mediated High-level Aminoglycoside Resistance in Carbapenem-resistant Klebsiella pneumoniae Isolates

Introduction: Carbapenemase-producing Klebsiella pneumoniae has become a leading cause of nosocomial infections in recent years, and aminoglycoside antibiotics have gained importance in the treatment of these infections due to their broad antimicrobial spectra, rapid bactericidal effects, and synergistic interactions with other antimicrobials. However, the excessive use of aminoglycosides has led to resistance. The aim of this study was to investigate plasmid-mediated, high-level resistance to aminoglycosides associated with 16S ribosomal RNA methyltransferases (16S-RMTase) in carbapenem-resistant K. pneumoniae isolates

In vitro susceptibility of OXA-48, NDM, VIM and IMP enzyme-producing Klebsiella spp. and Escherichia coli to fosfomycin

Introduction: Infections caused by Carbapenemase-producing Enterobacterales (CPE) are an important public health issue. Intravenous fosfomycin can be considered as an alternative for the treatment of serious infections caused by CPE. In this study, in vitro activity of fosfomycin was investigated among CPE isolates

EUCAST rapid antimicrobial susceptibility testing (RAST) in blood cultures: Validation in 55 european laboratories

© The Author(s) 2020.Objectives: When bloodstream infections are caused by resistant bacteria, rapid antimicrobial susceptibility testing (RAST) is important for adjustment of therapy. The EUCAST RAST method, directly from positive blood cultures, was validated in a multi-laboratory study in Europe. Methods: RAST was performed in 40 laboratories in northern Europe (NE) and 15 in southern Europe (SE) from clinical blood cultures positive for Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus or Streptococcus pneumoniae. Categorical results at 4, 6 and 8 h of incubation were compared with results for EUCAST standard 16–20 h disc diffusion. The method, preliminary breakpoints and the performance of the laboratories were evaluated. Results: The total number of isolates was 833/318 in NE/SE. The number of zone diameters that could be read (88%, 96% and 99%) and interpreted (70%, 81% and 85%) increased with incubation time (4, 6 and 8 h). The categorical agreement was acceptable, with total error rates in NE/SE of 2.4%/4.9% at 4 h, 1.1%/3.5% at 6 h and 1.1%/3.3% at 8 h. False susceptibility at 4, 6 and 8 h of incubation was below 0.3% and 1.1% in NE and SE, respectively, and the corresponding percentages for false resistance were below 1.9% and 2.8%. After fine-tuning breakpoints, more zones could be interpreted (73%, 89% and 93%), with only marginally affected error rates. Conclusions: The EUCAST RAST method can be implemented in routine laboratories without major investments. It provides reliable antimicrobial susceptibility testing results for relevant bloodstream infection pathogens after 4–6 h of incubation