[Monoclonal spread of multi-drug resistant CTX-M-15-producing Klebsiella pneumoniae. Impact of measures to control the outbreak]

Rev Esp Quimioter. 2018 Jun;31(3):237-246. Epub 2018 May 18.
[Article in Spanish]

Abstract

Objective: To describe an outbreak of multi-drug resistant extended-spectrum β-lactamases-producing Klebsiella pneumoniae (MDR-ESBL-KPN) and the impact of measures for its control.

Methods: We reviewed the patients´ clinical records with MDR-ESBL-KPN isolation during 2013-2016 with resistance to fluoroquinolones, aminoglycosides, fosfomycin, and nitrofurantoin; susceptible to imipenem, meropenem, colistin, and tigecycline and variable to ertapenem and cotrimoxazole (Vitek-2). The genetic relationship between 35 isolates was established by PFGE and MLST. Control measures were put in place in January 2016.

Results: We detected 269 patients colonized and/or infected by KPN-ESBL-MDR with a common resistance phenotype; the strains studied carried the blaCTX-M-15 gene and formed a single cluster belonging to ST11. The outbreak was detected at the end of 2015, although it began in 2013 in an elderly center. The acquisition source of the strains was: 6% community-acquired, 37% hospital-acquired (76% in internal medicine) and 57% related to long health care facilities (78% of hospitalizations in the last year). Ninety-four percent of patients had at least one underlying disease, 90% received antibiotics previously and 49% had some invasive devices. After the introduction of control measures, the incidence of cases in the quarter was reduced from 29 to 15.

Conclusions: We detected a monoclonal outbreak of MDR-CTX-M-15-KPN in 2015, with predominance of health-care associated cases. The success in the rapid spread of the outbreak was due to the delay in its detection and to the fact that most of the patients had previously received antibiotics. The control measures reduced the number of isolates by 50%.

Objetivo: Describimos un brote por Klebsiella pneumoniae productora de β-lactamasas de espectro extendido multirresistente (KPN-BLEE-MDR) y el impacto de las medidas de control.

Material y métodos: Revisamos las historias clínicas de los pacientes con aislamiento de KPN-BLEE-MDR durante 2013-2016 con resistencia a fluoroquinolonas, aminoglucósidos, fosfomicina y nitrofurantoína, sensibilidad a imipenem, meropenem, colistina, tigeciclina y variable a ertapenem y cotrimoxazol (Vitek-2). La relación genética entre 35 aislados se estableció mediante PFGE y MLST. En enero de 2016 se implantaron medidas para el control del brote.

Resultados: Detectamos 269 pacientes colonizados y/o infectados por KPN-BLEE-MDR con un fenotipo de resistencia común; las cepas estudiadas portaban el gen blaCTX-M-15 y formaban un único clúster perteneciente al ST11. El brote se detectó a finales de 2015, con origen en 2013 en una residencia de mayores. La adquisición de las cepas fue: 6% comunitaria, 37% hospitalaria (76% en medicina interna) y 57% relacionada con asistencia sanitaria (78% de ingresos en el último año). El 94% presentó al menos una patología de base, el 90% había recibido antibióticos previamente y el 49% presentó algún tipo de instrumentación. Tras implantar las medidas de control el número de colonizados/infectados trimestral pasó de 29 a 15.

Conclusiones: En 2015 detectamos un brote monoclonal de KPN-CTX-M-15-MDR relacionado fundamentalmente con la asistencia sanitaria. El éxito de su difusión se debió al retraso en su detección y a que la mayoría de los pacientes había recibido antibióticos previamente. Las medidas adoptadas para su control redujeron en un 50% el número de aislamientos.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / pharmacology
  • Child
  • Community-Acquired Infections / microbiology
  • Cross Infection / microbiology
  • Disease Outbreaks
  • Drug Resistance, Multiple, Bacterial / genetics*
  • Female
  • Humans
  • Incidence
  • Klebsiella Infections / drug therapy*
  • Klebsiella Infections / epidemiology
  • Klebsiella Infections / microbiology
  • Klebsiella pneumoniae / drug effects*
  • Klebsiella pneumoniae / enzymology
  • Male
  • Middle Aged
  • Phenotype
  • Retrospective Studies
  • Young Adult
  • beta-Lactamases / genetics
  • beta-Lactamases / metabolism*

Substances

  • Anti-Bacterial Agents
  • beta-Lactamases