A geographic cluster of healthcare-associated carbapenemase-producing hypervirulent Klebsiella pneumoniae sequence type 23

Hypervirulent Klebsiella pneumoniae has typically been associated with invasive, community-associated infections. This study describes the molecular, epidemiological and clinical characteristics of a cluster of carbapenemase-producing hypervirulent K. pneumoniae in the South-East of Ireland. It highlights the increasing risk that hypervirulent K. pneumoniae poses to healthcare and residential care populations. A retrospective analysis of sequences on K. pneumoniae isolates in the K. pneumoniae database of the National Carbapenemase-Producing Enterobacterales Reference Laboratory Service was performed to identify cases of hypervirulent K. pneumoniae from one hospital network. Hypervirulence scores were assigned based on the presence of recognised hypervirulence genes. A retrospective review of patient records was carried out for all confirmed cases of hypervirulent K. pneumoniae identified and clinical, epidemiological and molecular characteristics described. Twenty-eight cases of hypervirulent OXA-48 producing K. pneumoniae were identified over a 2-year period. All isolates were sequence-type 23 with a hypervirulence score of 5. All isolates carried the bla OXA-48 carbapenemase gene. All cases had a record of current or recent hospitalisation or residence in a long-term residential care facility. This study describes extensive dissemination of hypervirulent K. pneumoniae within healthcare facilities and an ongoing outbreak in our region. It shows the convergence of hypervirulence and antibiotic resistance determinants. Healthcare facilities need to consider their infection prevention, control and surveillance strategies to monitor and prevent further dissemination among a vulnerable population. Diagnostic laboratories need to ensure they have the ability and capacity for testing. Readily deployed laboratory methods for detection of hypervirulence are required.