Surgical site infection with extended-spectrum β-lactamase-producing Enterobacteriaceae after cardiac surgery: incidence and risk factors.

OBJECTIVE: To determine the incidence, microbiology and risk factors for sternal wound infection (SWI) with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) following cardiac surgery.

METHODS: We performed a retrospective analysis between January 2006 and December 2015 of prospective surveillance of a cohort of patients with cardiac surgery at a single centre (Paris, France). SWI was defined as the need for reoperation due to sternal infection. All patients with an initial surgery under extracorporeal circulation and diagnosed with an SWI caused by Enterobacteriaceae isolates were included. We compared patients infected with at least one ESBL-PE with those with SWI due to other Enterobacteriaceae by logistic regression analysis.

RESULTS: Of the 11 167 patients who underwent cardiac surgery, 412 (3.7%) developed SWI, among which Enterobacteriaceae were isolated in 150 patients (36.5%), including 29 ESBL-PE. The main Enterobacteriaceae (n = 171) were Escherichia coli in 49 patients (29%) and Enterobacter cloacae in 26 (15%). Risk factors for SWI with ESBL-PE in the multivariate logistic regression were previous intensive care unit admission during the preceding 6 months (adjusted odds ratio (aOR) 12.2; 95% CI 3.3-44.8), postoperative intensive care unit stay before surgery for SWI longer than 5 days (aOR 4.6; 95% CI 1.7-11.9) and being born outside France (aOR 3.2; 95% CI 1.2-8.3).

CONCLUSIONS: Our results suggest that SWI due to ESBL-PE was associated with preoperative and postoperative unstable state, requiring an intensive care unit stay longer than the usual 24 or 48 postoperative hours, whereas being born outside France may indicate ESBL-PE carriage before hospital admission.