title: [Copper activity against multiresistant Gram negative bacilli isolated from Chilean hospitals].
abstract: BACKGROUND
  Multiresistant nosocomial pathogens, especially Gram-negative bacilli (GNB), are a serious problem for public health systems worldwide. Due to their antimicrobial properties, copper alloys have been suggested as an alternative for the control of bacterial burden in surfaces in hospital environment. However, antibiotic multiresistance and copper resistance could be associated in GNB, and there is evidence that both kind of resistance genes (antibiotic and copper) can be located on the same genetic structures. For this reason antibiotic-multiresistant strains could survive in the presence of copper, selecting for bacterial phenotypes resistant to both antibacterial agents.
  
  
  OBJECTIVE
  To evaluate antibacterial activity of copper against nosocomial extended-spectrum β-lactamases (ESBL) (+) and ESBL (-) GNB, and carbapenems resistant or susceptible strains.
  
  
  METHODS
  This study included 390 strains of GNB isolated from Chilean hospitals: Acinetobacter baumannii and Pseudomonas aeruginosa resistant (CAR R) and susceptible (CAR S) to carbapenem antibiotics, and Klebsiella pneumoniae and Escherichia coli producers and non-producers of ESBL. Susceptibility levels to cupric sulphate were determined by agar dilution method and statistical analysis were used to determine the significance of the differences in the copper tolerance levels between the strains groups.
  
  
  RESULTS
  Statistically superior copper tolerance levels were found in the CAR R and ESBL producing strains of A. baumannii and K. pneumoniae, in relation with the CAR S and ESBL not-producing strains.
  
  
  CONCLUSIONS
  A relation between a diminished susceptibility to ionic copper and to recent generation antimicrobial agents was observed in K. pneumoniae y A. baumannii strains.
authors: Departamento de Microbiología, Universidad de Concepción, Concepción, Chile.
authors: Tomás
authors: T
authors: Kappes
authors: Mariana
authors: M
authors: Domínguez
authors: Helia
authors: H
authors: Bello
authors: Sergio
authors: S
authors: Mella
authors: Gisela
authors: G
authors: Riedel
authors: Gerardo
authors: G
authors: González-Rocha
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003300:Copper / Q000494:pharmacology*; D019327:Copper Sulfate / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects*; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D003300:Copper; D001618:beta-Lactamases; D019327:Copper Sulfate