title: [The relevance of correct identification and interpretation of susceptibility testing of Aeromonas spp. bacteremia isolates].
abstract: OBJECTIVE
  To assess the relevance of correct identification and interpretation of susceptibility testing of Aeromonas spp. bacteremia isolates using newly developed molecular methods in comparison to previous conventional methods.
  
  
  METHODS
  The study included 22 patients with bacteremia due to Aeromonas hydrophila group, microbiologically characterized using the MicroScan system. Further identification to species level was performed by mass spectrometry, and confirmed by sequencing the rpoB gene. The MIC of imipenem, cefotaxime, piperacillin-tazobactam, ciprofloxacin and cotrimoxazole was studied using a commercial broth microdilution and antibiotic gradient strips with low and high inocula. Detection of carbapenemase production was performed using the modified Hodge test, and was confirmed by amplifying the cphA gene by PCR.
  
  
  RESULTS
  A total of 9 (40.9%) isolates were identified as Aeromonas hydrophila, 8 (36.4%) as Aeromonas veronii, and the remaining 5 (22.7%) isolates as Aeromonas caviae. Resistance to beta-lactams according to both the commercial microdilution and MIC gradient strips methods was: 36%-50% to imipenem; 4%-56% to cefotaxime, and 27%-56% to piperacillin/tazobactam. The agreement between results generated by the automated system and the diffusion antibiotic gradient strip was, for all 3 species, 68% for imipenem, 50% to cefotaxime, and 46% to piperacillin/tazobactam. No resistance to cotrimoxazole and ciprofloxacin was found by either of the two methods, although 22.7% of the strains were resistant to nalidixic acid.
  
  
  CONCLUSIONS
  It is essential to identify the isolates of Aeromonas spp. at the species level, due to the fact that beta-lactam resistance is species- and method-dependent. The high rate of resistance to beta-lactam and quinolones reduce their application as empiric treatments for invasive infection by Aeromonas ssp.
authors.affiliation: Unidad Clínica de Enfermedades Infecciosas, Microbiología y Medicina Preventiva (UCEIMP), Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, España. Electronic address: anichi00@hotmail.com.
authors.forename: Ana
authors.initials: A
authors.lastname: Ruiz-Castillo
authors.affiliation: Unidad Clínica de Enfermedades Infecciosas, Microbiología y Medicina Preventiva (UCEIMP), Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, España.
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Lepe-Jiménez
authors.affiliation: Facultad de Medicina, Universidad de Sevilla, Sevilla, España.
authors.forename: María José
authors.initials: MJ
authors.lastname: Torres-Sánchez
authors.affiliation: Unidad Clínica de Enfermedades Infecciosas, Microbiología y Medicina Preventiva (UCEIMP), Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, España.
authors.forename: María José
authors.initials: MJ
authors.lastname: Artacho-Reinoso
authors.affiliation: Unidad Clínica de Enfermedades Infecciosas, Microbiología y Medicina Preventiva (UCEIMP), Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, España.
authors.forename: Javier
authors.initials: J
authors.lastname: Aznar-Martín
mesh_terms: D000333:Aeromonas / Q000187:drug effects*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D018440:beta-Lactam Resistance; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams
keywords: Aeromonas; Antibiotics; Antibióticos; MALDI-TOF; Resistance; Resistencia; Tratamiento; Treatment