title: Characterization of the enzyme aac(3)-Id in a clinical isolate of Salmonella enterica serovar Haifa causing traveler's diarrhea.
abstract: BACKGROUND
  The objective of this investigation was to identify the mechanism of decreased susceptibility to gentamicin in a Salmonella clinical isolate, leading to the detection of a aminoglycoside acetyltransferase gene found in a class 1 integron.
  
  
  METHODS
  A multidrug-resistant Salmonella strain was recovered from feces of a traveler to Egypt. The antimicrobial susceptibility test to 12 antimicrobial agents was performed with the Kirby-Bauer method. The presence of class 1 integron was determined by PCR. The amplified product was recovered and sequenced in order to establish the genes carried. In addition, susceptibility to gentamicin C1a, gentamicin C1, sisomicin, neomycin, dibekacin, kanamycin, tobramycin, amikacin, netilmicin, apramycin, dactimicin, spectinomycin, streptomycin, lividomycin and butirosin, was established. The Champion pET101 Directional TOPO Expression Kit was used to clone and express the aac(3)-I gene.
  
  
  RESULTS
  The isolate was identified as Salmonella enterica serovar Haifa, showing resistance to nalidixic acid, tetracycline and decreased susceptibility to gentamicin. One integron with a size circa 1,500 bp, encoding an aac(3)-Id plus aadA7 genes was observed. The analysis of the susceptibility to different aminoglycosides in the E. coli TOP10F' transformed with the vector carrying aac(3)-Id gene showed resistance to gentamicin C1a, gentamicin C1, and dactimicin, in accordance with the presence of this enzyme but, was susceptible to sisomicin. The homology of the amino acid and nucleotide sequences with the AAC(3)-Id enzyme was of 100%.
  
  
  CONCLUSIONS
  The presence of the AAC(3)-Id enzyme was described for the first time in a S. Haifa.
authors.affiliation: Servicio de Microbiología, IDIBAPS, Hospital Clínic, Barcelona, Spain.
authors.forename: Roberto
authors.initials: R
authors.lastname: Cabrera
authors.forename: Joaquím
authors.initials: J
authors.lastname: Ruiz
authors.forename: Javier
authors.initials: J
authors.lastname: Sánchez-Céspedes
authors.forename: Pilar
authors.initials: P
authors.lastname: Goñi
authors.forename: Rafael
authors.initials: R
authors.lastname: Gómez-Lus
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Jiménez de Anta
authors.forename: Joaquím
authors.initials: J
authors.lastname: Gascón
authors.forename: Jordi
authors.initials: J
authors.lastname: Vila
mesh_terms: D000123:Acetyltransferases / Q000302:isolation & purification*; D003967:Diarrhea / Q000382:microbiology*; D006801:Humans; D019779:Salmonella enterica / Q000145:classification* / Q000201:enzymology* / Q000302:isolation & purification; D014195:Travel
chemical_list: D000123:Acetyltransferases; C019681:aminoglycoside acetyltransferase