Outbreak of CTX-M-3-type extended-spectrum β-lactamase-producing Enterobacter cloacae in a pediatric ward

A first resistant strain of Enterobacter cloacae was isolated from a blood specimen in a pediatric patient with immature teratoma-developed sepsis after combination chemotherapy. The strain produced extended-spectrum β-lactamase (ESBL), and the same ESBL-producing strains were detected in urine samples from other patients in the pediatric ward. All strains harbored genes for blaCTX-M-3 by polymerase chain reaction (PCR) and sequencing analysis. Analysis of pulsed-field gel electrophoresis revealed that all strains were the same clonal type. These results suggest that ESBL-producing strains might be transmitted in the ward via contact among patients or medical staff.