title: Molecular detection of ESBLs production and antibiotic resistance patterns in Gram negative bacilli isolated from urinary tract infections.
abstract: BACKGROUND
  β-lactam resistance is more prevalent in Gram negative bacterial isolates worldwide, particularly in developing countries. In order to provide data relating to antibiotic therapy and resistance control, routine monitoring of corresponding antibiotic resistance genes is necessary.
  
  
  OBJECTIVE
  The aim of this study was the characterization of β-lactam resistance genes and its plasmid profile in bacteria isolated from urinary tract infection samples.
  
  
  METHODS
  In this study, 298 Gram negative bacteria isolated from 6739 urine specimens were identified by biochemical standard tests. Antimicrobial susceptibility testing was performed by the disk diffusion method. Extended-spectrum β-lactamase (ESBL)-producing strains were also detected by the double-disk synergy test. The presence of blaTEM and blaSHV genes in the strains studied was ascertained by polymerase chain reaction.
  
  
  RESULTS
  Of all Gram negative bacteria, Escherichia coli (69.1%) was the most common strain, followed by Klebsiella sp. (12.1%), Enterobacter sp. (8.4%), Proteus sp. (4.4%), Citrobacter (4%) and Pseudomonas sp. (2%). The most antibiotic resistance was shown to tetracycline (95.16%), nalidixic acid (89.78%) and gentamycin (73.20%) antibiotics. Among all the strains tested, 35 isolates (11.75%) expressed ESBL activity. The prevalence of TEM and SHV positivity among these isolates was 34.29%, followed by TEM (31.43%), TEM and SHV negativity (20.0%) and SHV (14.29%), respectively.
  
  
  CONCLUSIONS
  Regular monitoring of antimicrobial drug resistance seems necessary to improve our guidelines in the use of the empirical antibiotic therapy.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Kargar
authors.affiliation: Department of Microbiology, Jahrom Branch, Islamic Azad University, Jahrom, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Kargar
authors.forename: Mohammad Zareian
authors.initials: MZ
authors.lastname: Jahromi
authors.forename: Akram
authors.initials: A
authors.lastname: Najafi
authors.forename: Sadegh
authors.initials: S
authors.lastname: Ghorbani-Dalini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D005260:Female; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D014552:Urinary Tract Infections / Q000382:microbiology*; D055815:Young Adult; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism*
chemical_list: D001618:beta-Lactamases