Emergence of pan-resistant VIM1 producing Klebsiella pneumoniae in Belgian hospitals

Abstract number: P1692

Glupczynski Y., Rodrigues-Villalobos H., Bogaerts P., Blairon L., Gérard M., Aoun M., Deplano A., Struelens M.J., Jans B.

Objectives: The emergence of carbapenemases in Enterobacteriaceae is becoming a matter of concern. We studied the microbiological characteristics and epidemiological data of VIM-1 producing K. pneumoniae (VPKP) isolates recovered from clinical specimens of patients hospitalised in Belgian hospitals.

Methods: Antibiotic susceptibilities were determined using standard agar diffusion, VITEK2 and Etest MIC determination. The production of metallo-b-lactamase (MBL) was examined by synergy testing with imipenem and EDTA. Isolates were typed by PFGE. Detection of blaVIM-1 and mapping of the VIM-1 encoding integrons were performed by PCR-sequencing. b-lactamase activities were analyzed by IEF and spectrophotometry.

Results: Between 06/08 and 08/08, 5 patients with VPKP isolates were identified in 3 teaching hospitals in Brussels. At hospital A and B, VPKP were detected from rectal swabs by screening upon admission in 2 patients transferred from a Greek hospital where they had been treated in an ICU. At hospital C, VPKP were found in clinical specimens (post-operative wounds [2], lower respiratory tract [1]) in 3 patients with severe underlying diseases hospitalised in 3 units. All patients were colonised and none of them developed an infection. No common epidemiological transmission link could be established between any patients. By PFGE, the 5 isolates clustered in 2 clones and 4 variants.

All VPKP isolates showed a positive synergy test with EDTA, had high resistance level to meropenem and imipenem (MICs >32 mg/L) detected by disk diffusion and automated systems. They were pan-resistant but susceptible to aztreonam and gentamicin only; 4/5 strains were also resistant to colistin (MIC= 16 mg/L). Tigecycline was active against 4/5 strains (one isolate with intermediate resistance, MIC= 4 mg/L). blaVIM-1 was part of a class 1 integron that also carried aacA7, dhfr1, aadA1 and sul1. After implementing additional contact precautions and a nationwide alert system, no new cases were observed after 4 months of surveillance in the concerned hospital. Only one additional sporadic case was detected at another hospital.

Conclusions: Emergence of VIM-1 MBL-producing, pan-resistant K. pneumoniae is reported for the first time in Belgium. This event confirms the potential risk of spread of multiresistant bacteria with international transfer of patients between acute care hospitals and highlights the value of early screening and control measures to contain their spread.