title: Frequency distribution of genes encoding aminoglycoside modifying enzymes in uropathogenic E. coli isolated from Iranian hospital.
abstract: BACKGROUND
  Escherichia coli is considered as the most common cause of urinary tract infection (UTI) and acquired multiple resistances to a wide range of antibiotics such as aminoglycosides. Enzymatic alteration of aminoglycosides (AMEs) by aminoglycoside- modifying enzymes is the main mechanism of resistance to these antibiotics in E. coli. The aim of this study was detection and investigation of frequency of genes encoding aminoglycoside modifying enzymes (aac(3)-IIa and ant(2'')-Ia) in UPEC isolated from hospitalized patients in teaching hospital of Tehran, Iran.
  
  
  RESULTS
  A total of 276 UPEC were obtained from Urine samples in a hospital from Tehran. Antibiotic susceptibility to aminoglycosides was determined by disk diffusion method according CLSI guidelines in UPEC isolates. MICs of target antibiotics were determined by agar dilution method. All isolates were screened for the presence of the AMEs genes using the PCR. The results of disk diffusion showed 21%, 24.6%, 23.18%, 3.62% and 6.15% of isolates were resistant to Gentamicin, Tobramycin, Kanamicin, Amikacin and Netilmicin respectively. The agar dilution's results (MICs) were high, 66.19% for Gentamicin. The aac (3)-IIa and ant(2″)-Ia genes were detected in (78.87%) and 47.88% of isolates respectively.
  
  
  CONCLUSIONS
  This study shows the high frequency of genes encoding (AMEs) aac(3)-IIa and ant(2")-Ia genes and their relationship between different aminoglycoside resistance phenotypes.
authors.affiliation: Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Po Box:14115-158, Tehran, Iran. n.soleimani@modares.ac.ir.
authors.forename: Neda
authors.initials: N
authors.lastname: Soleimani
authors.forename: Mahdi
authors.initials: M
authors.lastname: Aganj
authors.forename: Liaqat
authors.initials: L
authors.lastname: Ali
authors.forename: Leili
authors.initials: L
authors.lastname: Shokoohizadeh
authors.forename: Türkân
authors.initials: T
authors.lastname: Sakinc
mesh_terms: D000583:Amikacin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D052978:Disk Diffusion Antimicrobial Tests; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D005787:Gene Frequency; D005798:Genes, Bacterial; D005839:Gentamicins / Q000494:pharmacology; D006784:Hospitals, Teaching; D006801:Humans; D007492:Iran; D007612:Kanamycin / Q000494:pharmacology; D009428:Netilmicin / Q000494:pharmacology; D014031:Tobramycin / Q000494:pharmacology; D014552:Urinary Tract Infections / Q000188:drug therapy / Q000382:microbiology; D056689:Uropathogenic Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; D009428:Netilmicin; D007612:Kanamycin; D000583:Amikacin; D014031:Tobramycin