Restricción programada de cefalosporinas de tercera generación en contexto de un brote de bacilos gramnegativos productores de β-lactamasas tipo AmpC en unidades críticas: una experiencia de la vida real

Background: Programmed restriction (PR) of antimicrobials can selectively decrease the rate of infections by certain microorganisms. In this sense, AmpC β-lactamase-producing gram-negative bacilli (GNB- bla AmpC ) are selected for the overuse of third generation cephalosporins (3GC). These bacteria also acquire genes and co-produce other β-lactamases, such as Nueva Delhi ones (GNB- bla NDM ). Aim: To decrease the isolation rate of GNB- bla AmpC and GNB- bla NDM in cultures from ICU patients after a PR of 3GC. Methods: Quasi-experimental study, before (P 1 = 12 months) and after (P 2 = 12 months) a PR of 3GC in an adults´ hospital. The use of antibiotics was expressed as “percentage days of treatment (%DOT)” /100 beds occupied per day (100-BOD). The rates of GNB- bla AmpC and GNB- bla NDM were compared in blood cultures (BC), mini-bronchio alveolar lavages (mB) and urine cultures (UC) in the ICU. Results: In P 2 , 3GC consumption was 2.5% DOT/100-COD. There was a decrease in GNB- bla AmpC from BC (RR 0,48 [0,2-0,9] p<0,02) and mB (RR 0,52 [0,3-0,9] p<0,02), as well as of GNB- bla NDM from BC (RR 8,1 [1,6-39,4] p<0,00). Conclusions: PR of 3GC was linked to the reduction of GNB- bla AmpC and GNB- bla NDM in BC, as well as GNB- bla AmpC in mB from ICU patients.