The Route of Antimicrobial Resistance From the Hospital Effluent to the Environment: Focus on the Occurrence of KPC-producing Aeromonas Spp. And Enterobacteriaceae in Sewage

Diagn Microbiol Infect Dis. 2013 May;76(1):80-5. doi: 10.1016/j.diagmicrobio.2013.02.001. Epub 2013 Mar 9.


We investigated the antimicrobial resistance profile and the occurrence of Klebsiella pneumoniae carbapenemase (KPC)-producing Gram-negative rods in sewage samples obtained from a Brazilian teaching hospital and from the wastewater treatment plant (WWTP) that receives it for treatment. We identified multidrug-resistant bacteria as well as KPC-2-producing Aeromonas spp. and several Enterobacteriaceae species, including Kluyvera spp., in the hospital effluent and in different sites of the WWTP. Most isolates showed the blaKPC-2 gene harbored on a transposon that was carried by conjugative plasmids. The presence of KPC production among Aeromonas spp., Kluyvera spp., and other Enterobacteriaceae indicates the adaptability of such isolates to aquatic environments, not only in the hospital effluent but also throughout the WWTP. Although secondary treatment seems to decrease the amount of KPC producers in sewage, multidrug-resistant isolates are continually disposed in the urban river. Thus, sewage treatment regulations are urgently needed to decelerate the evolution of antimicrobial resistance beyond hospitals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter / drug effects
  • Acinetobacter / isolation & purification
  • Aeromonas / drug effects
  • Aeromonas / isolation & purification*
  • Bacterial Proteins / genetics*
  • Brazil
  • DNA Transposable Elements
  • Drug Resistance, Multiple, Bacterial*
  • Enterobacteriaceae / drug effects
  • Enterobacteriaceae / isolation & purification*
  • Hospitals, Teaching
  • Kluyvera / drug effects
  • Kluyvera / isolation & purification*
  • Microbial Sensitivity Tests
  • Plasmids / genetics
  • Pseudomonas / drug effects
  • Pseudomonas / isolation & purification
  • Sewage / microbiology*
  • beta-Lactamases / genetics*


  • Bacterial Proteins
  • DNA Transposable Elements
  • Sewage
  • beta-Lactamases
  • carbapenemase-2, Klebsiella pneumoniae