Screening of ESBL-producing Enterobacteriacae concomitant with low degree of transmission in intensive care and bone marrow transplant units.

Background: Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) are spreading worldwide in both hospital and community settings. In this study, the molecular epidemiology and the transmission modalities of ESBL-E in intensive care- and bone marrow transplant were investigated.

Methods: All patients included in this study were screened for presence of ESBL-E on admission and weekly. Relevant β-lactamase genes were identified by PCR and sequencing.

Results: A total of 669 patients were included in this study. On admission, ESBL-producing Escherichia coli were detected in 49 (7.3%) patients and ESBL-producing Klebsiella pneumoniae in one patient. The most common ESBL types among E. coli isolates were CTX-M-15 (38.8%) and CTX-M-1 (38.8%). Furthermore, 12 of 49 (24.5%) ESBL-producing E. coli could be assigned to the epidemic clone ST131. A single patient acquired ESBL-producing E. coli during the hospital stay but cross-transmission could not be demonstrated. Among 1095 environmental samples none revealed ESBL.

Conclusions: Our results suggest that early detection of ESBL-producing Enterobacteriaceae and consequent implementation of basic hygiene measures and contact isolation may reduce the transmission rate during the hospital stay.