A case of sepsis caused by Enterobacter cloacae producing both type SHV-12 and type CTX-M-14 ESBLs in a post bone-marrow transplantation patient

Third-generation cephalosporin-resistant Enterobacter cloacae was isolated from the blood culture of a 31-year-old woman after bone-marrow transplantation. Since this strain was resistant to third-generation cephalosporins, the production of extended-spectrum beta-lactamases (ESBLs) was suspected. PCR and a sequence analysis confirmed two ESBL genes, bla(SHV-12) and bla(CTX-M-14). No bacteria were detected after meropenem was administered, and symptoms abated. This is, to our knowledge, the first report in Japan of E. cloacae clinical isolates simultaneously producing both SHV-12 and CTX-M-14 ESBL. In cases where chromosomal AmpC over-production of E. cloacae concomitantly produces ESBL, caution should be exercised due to the potential development of resistance against extended-spectrum beta-lactam agents.