Nosocomial spread of Klebsiella pneumoniae isolates producing blaGES-4 carbapenemase at a Japanese hospital

Abstract Six Klebsiella pneumoniae clinical isolates resistant to various cephalosporins and cephamycins were identified in a Japanese general hospital, a tertiary care hospital, between November 2009 and April 2010. All K. pneumoniae isolates carried bla GES-4 and bla SHV-1 , while 2 K. pneumoniae isolates also harbored bla CTX-M-15 . The pulsed-field gel electrophoresis patterns revealed that these 6 K. pneumoniae isolates were almost identical, suggesting their clonal relatedness. Plasmid profiles and conjugation assays revealed that these bla GES-4 genes were located on similar conjugative plasmids. These data indicate that nosocomial spread caused by K. pneumoniae isolates producing bla GES-4 carbapenemase occurred at a Japanese general hospital. K. pneumoniae isolate harboring bla GES-4 is rarely reported in Japan, and, to the best of our knowledge, this is the second report of K. pneumoniae isolates harboring bla GES-4 that occurred nosocomial spread in Japan.