In vitro activity of eravacycline and cefoperazone/ sulbactam against extensively-drug resistant and pan-drug resistant Acinetobacter baumannii isolates from a tertiary hospital in Greece.

We evaluated the in vitro activity of eravacycline and cefoperazone/sulbactam against 42 XDR and 58 PDR Acinetobacter baumannii isolates from blood and bronchoalveolar infections. The minimum and maximum MICs for eravacycline were 0.125 and 4 mg/L, respectively. The MIC50 was 2 mg/L and the MIC90 was 3 mg/L. The minimum and maximum MICs for cefoperazone/sulbactam were 24 and >256 mg/L, respectively. The MIC50 and MIC90 were both >256 mg/L. These novel agents were not adequate for the treatment of A. baumannii infections in our hospital and we recommend that mi- crobiology laboratories perform their own evaluations before including them in clinical practice.

Rapid Reversal of Carbapenemase-Producing Pseudomonas aeruginosa Epidemiology from blaVIM- to blaNDM-harbouring Isolates in a Greek Tertiary Care Hospital.

Carbapenemase-producing Pseudomonas aeruginosa strains present a specific geographical distribution regarding the type of carbapenemase-encoding genes that they harbor. For more than twenty years, VIM-type enzymes were the only major carbapenemases that were detected among P. aeruginosa isolates in Greece until the emergence of NDM-1-encoding P. aeruginosa in early 2023. In the present study, we present the rapid reversal of the carbapenemase-producing P. aeruginosa epidemiology from blaVIM- to blaNDM-harbouring isolates that occurred in our hospital since then. Between January 2023 and February 2024, 139 isolates tested positive for carbapenemase production with the NG-Test CARBA 5 immunochromatographic assay. Eight isolates were processed with the Hybrispot antimicrobial resistance direct flow chip molecular assay, and the first NDM-producing isolate was further analyzed through whole genome sequencing and bioinformatics analysis. Multiple resistance genes were detected by molecular techniques in accordance with the extensively drug-resistant phenotype. The isolate that was subjected to whole-genome sequencing belonged to the P. aeruginosa high-risk clone ST308, and the blaNDM was located in the chromosome in accordance with previously reported data. During the study period, NDM-producing isolates were increasingly detected, and only five months after their emergence, they overcame VIM producers. Our results indicate the potential of this new clone to spread rapidly and predominate within healthcare institutions, further restricting the already limited treatment options.

Probable Three-Species In Vivo Transfer of blaNDM-1 in a Single Patient in Greece: Occurrence of NDM-1-Producing Klebsiella pneumoniae, Proteus mirabilis, and Morganella morganii.

NDM carbapenemase-encoding genes disseminate commonly among Enterobacterales through transferable plasmids carrying additional resistance determinants. Apart from the intra-species dissemination, the inter-species exchange of plasmids seems to play an additional important role in the spread of blaNDM. We here present the genetics related to the isolation of three species (Klebsiella pneumoniae, Proteus mirabilis, and Morganella morganii) harboring the blaNDM-1 gene from a single patient in Greece. Bacterial identification and antimicrobial susceptibility testing were performed using the Vitek2. Whole genome sequencing and bioinformatic tools were used to identify resistance genes and plasmids. BlaNDM-1 harboring plasmids were found in all three isolates. Moreover, the plasmid constructs of the respective incomplete or circular contigs showed that the blaNDM-1 and its neighboring genes form a cluster that was found in all isolates. Our microbiological findings, together with the patient's history, suggest the in vivo transfer of the blaNDM-1-containing cluster through three different species in a single patient.