Emergence of Enterobacteriaceae producing VIM-1 metallo-b-lactamases in a tertiary hospital in Spain: clinical and epidemiological characteristics

Abstract number: R2427

Horcajada J.P., Segura C., Sorlí L., Salvadó M., Alvarez-Lerma F., Miró E., Navarro F., Knobel H.

Objectives: The emergence of carbapenemases in Enterobacteriaceae is becoming a matter of concern. We report the clinical and epidemiological data of patients infected or colonised with Enterobacteriaceae producing VIM-1 metallo-b-lactamases (MBL).

Methods: Retrospective descriptive study of patients infected or/and colonised with MBL producing Enterobacteriaceae in a 450-bed Hospital from December 2006 to May 2007. Clinical and epidemiological data were collected by means of charts and hospital data base review. Identification and susceptibility of isolates were done by MicroScan system (Urine ComboS1 and NC36 panels). To confirm carbapenem resistance, imipenem and ertapenem disc diffusion, imipenem and imipenem+EDTA E-test and the cloverleaf test were performed.

Results: During the study period 12 MBL-producing Enterobacteriaceae were isolated. One of them was isolated from a flexible endoscope in a rutine control. Data from one patient could not be obtained. Finally, 10 patients were studied. Six had E. cloacae, 3 K. oxytoca and 1 K. pneumoniae. Six (60%) were women. Mean (SD) age was 73 (14) years. Seven (70%) patients had chronic underlying conditions. Three (30%) patients had bacteraemia, 3 (30%) skin and soft tissue infection, 2 (20%) IV catheter colonisation, 1 (10%) respiratory infection and 1 (10%) peritonitis. All episodes were nosocomial acquired with a mean (SD) previous hospital stay of 27 (17) days (range 2–55). During the previous month, 8 (80%) patients had indwelling urinary catheter, 6 (60%) IV catheter, 5 (50%) had previous surgery, and 4 (40%) mechanical ventilation. Seven (70%) patients received antibiotics during the previous 2 months. Four of them received >3 Gram-negative active drugs and 3 patients were treated with carbapenems. Empirical treatment was inappropriate in 5 of 5 patients. However, none of them dead under empirical treatment. Antibiogram guided treatment was amikacin in 3 cases (one monotherapy, one combined with cotrimoxazole and one with colistin) and tygeciclin monotherapy in 2 cases, with good clinical outcome in all of them. Crude mortality rate was 60% and related mortality rate 1 (10%). Mean (SD) stay was 47 (28) days (range 17–102).

Conclusions: Emergence of VIM-1 MBL-producing Enterobacteriaceae in Spain is reported. Isolates are nosocomial acquired. Most of the patients have chronic conditions, receive multiple antimicrobials previously, and undergo invasive procedures during prolonged hospital stay.