Molecular Characteristics of GES-Type Carbapenemase-Producing Pseudomonas aeruginosa Clinical Isolates from Long-Term Care Facilities and General Hospitals in South Korea

Since carbapenems have been used for the treatment of infections in medical settings, multidrug-resistant Pseudomonas aeruginosa containing resistance for carbapenems has become a major cause of nosocomial infections worldwide. Information on carbapenemase-producing P. aeruginosa isolates at community hospitals, including long-term care facilities and general hospitals, has rarely been reported in South Korea. The aims of this study were to describe the characteristics of seven carbapenemase-producing P. aeruginosa isolates recovered from two long-term care facilities in South Korea. The carbapenemase genes were identified by PCR and sequencing. Strain typing was assessed by pulsed field gel electrophoresis and multilocus sequence typing (MLST) analysis. Isolates with a genomic island and class I integron surrounding bla(GES-type) were confirmed by the PCR mapping method. Of seven GES-type carbapenemase-producing P. aeruginosa isolates, the bla(GES-24) gene was detected in six isolates, and the bla(GES-5) gene was detected in one isolate. The epidemiological relatedness of the seven isolates carrying bla(GES-24) and bla(GES-5) showed >81% similarity. Five isolates carrying bla(GES-24) were sequence type 155 (ST155) by MLST, followed by one ST244 isolate carrying bla(GES-24) and one ST308 isolate carrying bla(GES-5). bla(GES-type) genes were embedded in two different class I integrons in a genomic island-15-like region. Our results indicate the possible spread of carbapenemase-producing P. aeruginosa and present a current threat of antimicrobial resistance in community hospitals.