Emergence of NDM-1-producing Pseudomonas aeruginosa Sequence Type 773 Clone: Shift of Carbapenemase Molecular Epidemiology and Spread of 16S rRNA Methylase Genes in Korea

Abstract

Imipenemase (IMP)-6-producing Pseudomonas aeruginosa sequence type (ST) 235 is a dominant clone of carbapenemase-producing P. aeruginosa (CPPAE) in Korea. As part of the Antimicrobial Resistance Surveillance System in Korea, we found an increase in the carbapenem resistance rate of P. aeruginosa isolates from blood cultures and a shift in the molecular epidemiology of CPPAE. A total of 212 non-duplicated P. aeruginosa blood iso-lates were obtained from nine general hospitals and two nursing homes. Twenty-four iso-lates were identified as CPPAE. We observed the emergence of the NDM-1 P. aeruginosa ST 773 clone (N= 10), mostly from Gyeongsang Province. The IMP-6 ST 235 clone (N= 11) was detected in all provinces. CPPAE isolates showed very high resistance rates to amika-cin, and all NDM-1 P. aeruginosa strains carried rmtB. This is the first nationwide surveil-lance of the recently emerged NDM-1-producing P. aeruginosa ST773 clone in Korea. Continuous surveillance is necessary to prevent the infection and transmission of carbape- nem-and amikacin-resistant P. aeruginosa in Korea.