[Bacteremia caused by Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae. A retrospective study of 7 years].

OBJECTIVE: Bacteremia caused by Klebsiella pneumoniae carbapenemase-producing strains (Kp-KPC) is associated with high mortality. The hypothesis of our work is that there was an increase in the levels of resistance to different antimicrobials in Kp-KPC isolated from bacteremia.

METHODS: Retrospective and descriptive study in two periods: Period 1 (P1) 2010-2014 and period 2 (P2) 2015-2016. We included patients ≥18 years old with bacteremia caused by Kp-KPC in a General Hospital. We defined active drug (AD) if it was in vitro susceptible and in the case of meropenem if it had a MIC ≤ 8 mg/L in combination treatment.

RESULTS: Fifty episodes of bacteremia caused by Kp-KPC were analyzed in 45 patients. (P1: 21 and P2: 29). The following variables were similar in both periods: median age (53 vs. 52 years); male sex (45 vs. 62%); site of infection: primary bacteremia (52 vs.45%), bacteremia associated with catheter (24 vs.17%), and other (24 vs. 38%). During P2 there was a significant increase in colistin resistance (28 vs. 69%) (p <0.01), an increase in MIC to meropenem ≥ 16 mg/L (74 and 97%) (p = 0.02), and decrease in tigecycline resistance (29 vs. 4%) (p = 0.02). The overall mortality was 40 in P1 and 32% in P2 (p=0.7). There was not difference in mortality when the definitive treatment was with an active antimicrobial vs. two active antimicrobials, as well as between the different antimicrobials used.

CONCLUSIONS: There was a significant increase in bacteremia caused by Kp-KPC and the level of colistin resistance and MIC to meropenem. Overall mortality was high in both periods.