A molecular survey of Greek hospitals shows the emergence and rapid spread of two new high-risk Klebsiella pneumoniae strains, researchers reported last week in Eurosurveillance.
For the study, a team led by researchers from Greece's National Public Health Organization and the European Centre for Disease Prevention and Control analyzed whole-genome sequences and epidemiologic data of 310 carbapenemase-producing K pneumoniae (CPKP) isolates collected from 15 Greek hospitals from 2013 to 2022. The purpose of the study was to determine the distribution of K pneumoniae sequence type (ST) 39, a highly drug-resistant clade that was detected in 12 of 15 Greek hospitals that participated in a European Union/European Economic Area (EU/EEA) genomic surveillance project on carbapenemase-producing Enterobacterales in 2019.
Five STs accounted for more than 90% of the CPKP isolates in the dataset: ST258/512 (101 isolates), ST11 (93), ST39 (56), ST147 (21), and ST323 (13). Even though the number of ST39 isolates found in 2022 was lower than in the same hospitals in 2019, the study showed it had spread to all 15 hospitals by 2022, marking it as a high-risk clone that can now be considered endemic in Greek hospitals. In addition, ST323, another highly drug-resistant clone that was not detected in the 2019 survey, was detected in 6 of the 15 hospitals.
"Even in a country with long-standing endemicity for CPKP such as Greece, the emergence of new high-risk clones is relevant as this is the starting point for further spread of these clones which usually have additional antimicrobial resistance mechanisms and/or are better adapted to transmission in healthcare settings," the study authors wrote.
Within-hospital transmission drives rapid emergence
Analysis of isolates collected in 2022 identified 44 within-hospital CPKP transmission events, a finding the authors say is likely responsible for the rapid emergence of ST39 and ST323 and needs to be urgently addressed.
"This situation is of concern and highlights the need for molecular surveillance and enhanced IPC [infection prevention and control] measures in hospitals in Greece and in other EU/EEA countries, and more generally increased efforts to control antimicrobial resistance in the EU/EEA and beyond," they concluded.