Evolución de la sensibilidad y de los aislados productores de β-lactamasas de espectro extendido en microorganismos gramnegativos en el estudio SMART en España (2011-2015)

espanolIntroduccion. El estudio SMART (Study for Monitoring Antimicrobial Resistance Trends) monitoriza la sensibilidad antimicrobiana y las β-lactamasas de espectro extendido (BLEE) en bacilos gramnegativos obtenidos de infecciones intraabdominales (IIA). Material y Metodos. Se ha analizado la sensibilidad antimicrobiana (microdilucion estandar, criterios EUCAST) y las BLEE (deteccion fenotipica) de 5.343 aislados de IIA en 11 centros del programa SMART-Espana durante 2011-2015 en comparacion con 2002-2010. Resultados. Escherichia coli, el microorganismo mas prevalente, disminuyo significativamente en las IIA de origen comunitario (60,9% 2002-2010 vs. 56,1% 2011- 2015, P=0,0003). Fue seguido en prevalencia por Klebsiella pneumoniae que aumento tanto en IIA comunitaria (8,9% vs. 10,8%, P=0,016) como nosocomial (9,2% vs. 10,8%, P=0,029) y por P. aeruginosa que aumento en la IIA comunitaria (5,6% vs. 8,0%, P=0,0003). Las BLEE fueron mas prevalentes en la IIA nosocomial por K. pneumoniae (16,3%) que por E. coli (9,5%), siendo mas frecuentes en pacientes de mayor edad (>60 anos). Considerando todas las Enterobacteriaceae, ertapenem (92,3- 100%) y amikacina (95,5%-100%) fueron los antimicrobianos mas activos. La sensibilidad a ertapenem, al contrario que a amoxicilina-clavulanico o piperacilina-tazobactam, se mantuvo sin cambios en E. coli con (98,8%) y sin BLEE (100%). Su sensibilidad disminuyo en BLEE-K. pneumoniae (74,7%) pero fue mayor que la de amoxicilina-clavulanico (14,0%) o piperacilina-tazobactam (24,0%). Es de resaltar que esta actividad se mantuvo >60% en los aislados con BLEE resistentes a amoxicilina-clavulanico, piperacilina-tazobactam o fluoroquinolonas. Conclusiones. El estudio SMART-Espana sustenta las guias actuales que incluyen al ertapenem como tratamiento empirico en la IIA leve-moderada comunitaria, en particular con BLEE. Estas recomendaciones precisaran actualizarse con la reciente introduccion de nuevos antimicrobianos. EnglishIntroduction. The SMART (Study for Monitoring Antimicrobial Resistance Trends) surveillance study monitors antimicrobial susceptibility and extended spectrum β-lactamases (ESBLs) in Gram-negative bacilli recovered from intra-abdominal infections (IAI). Material and methods. Antimicrobial susceptibility of 5,343 isolates from IAI recovered in 11 centres during the 2011-2015 SMART-Spain program was analysed by standard microdilution (EUCAST criteria) and compared with that from 2002-2010. ESBLs were phenotypically detected. Results. Escherichia coli, the most common isolate, significantly decreased in community acquired IAI (60.9% 2002-2010 vs. 56.1% 2011-2015, P=0.0003). It was followed in prevalence by Klebsiella pneumoniae that increased both in the community (8.9% vs. 10.8%, P=0.016) and nosocomial (9.2% vs. 10.8%, P=0.029) IAI and P. aeruginosa, which significantly increased in community acquired IAI (5.6% vs. 8.0%, P=0.0003). ESBLs were more prevalent in K. pneumoniae (16.3%) than in E. coli (9.5%) of nosocomial origin and were more frequently isolated from elderly patients (>60 years). Considering all Enterobacteriaceae, ertapenem (92.3-100%) and amikacin (95.5%-100%) were the most active antimicrobials. Ertapenem activity, unlike amoxicillinclavulanate or piperacillin-tazobactam, remained virtually unchanged in ESBL (100%) and non-ESBL (98.8%) E. coli producers. Its activity decreased in ESBL-K. pneumoniae (74.7%) but was higher than that of amoxicillin-clavulanate (14.0%) and piperacillin-tazobactam (24.0%). Interestingly, ertapenem susceptibility was maintained in >60% of ESBL isolates that were resistant to amoxicillin-clavulanate, piperacillin-tazobactam or fluoroquinolones. Conclusions. SMART-Spain results support current guidelines which include ertapenem as empiric treatment in mild-moderate community-acquired IAI, particularly with ESBL producers. These recommendations will need to be updated with the recently introduction of new antimicrobials.