title: Frequency of Antiseptic Resistance AmongStaphylococcus aureusand Coagulase-Negative Staphylococci Isolated From a University Hospital in Central Iran.
abstract: OBJECTIVE
  Reduced biocide susceptibility in Staphylococci is associated with various antiseptic resistance genes encoding efflux systems. Our aim was to determine the susceptibility to three disinfectant agents, including benzalkonium chloride (BAC), benzethonium chloride (BZT), and chlorhexidine digluconate (CHDG) among clinical isolates ofStaphylococcus aureusand coagulase-negative Staphylococci (CoNS).
  
  
  METHODS
  The minimum inhibitory concentration (MIC) of 60 methicillin-resistantS. aureus(MRSA), 54 methicillin-sensitiveS. aureus(MSSA) and 51 CoNS isolates from a single hospital to three biocidal agents (BAC, BZT, and CHDG) was determined. Biocide resistance genes (qacA/B, smr, qacG, qacH, qacJ, and norA) were analyzed by the polymerase chain reaction assay.
  
  
  RESULTS
  All isolates had MICs for BAC and BZT from 0.25 to 8 µg/mL, and for CHDG from 0.5 to 64 µg/mL.qacA/Bwas the most common biocide resistance gene among all 165 Staphylococcus isolates (76; 46%), which comprised 38 (63.3%) MRSA, 14 (25.9%) MSSA, and 24 (47%) CoNS. Eleven (6.7%) and 24 (14.5%) isolates among the 165 Staphylococci carriedsmrandnorAgenes, respectively. In contrast, other resistance genes such asqacG,qacH, andqacJwere absent in all Staphylococci studied. TheqacA/Bandsmrgenes were detected concomitantly in 3% of isolates, and 23.6% strains of the total 165 Staphylococcus isolates were negative for each studied gene.
  
  
  CONCLUSIONS
  The carriage of several biocide resistance genes, includingqacA/B,smr, andnorA, alone or concurrently, is associated with reduced susceptibility. Use of antiseptics may select for antibiotic-resistant strains and assist their survival in the healthcare environment.
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Nona
authors.initials: N
authors.lastname: Taheri
authors.affiliation: Laboratory Sciences Research Center, Golestan University of Medical Sciences, Gorgan, Iran; Department of Microbiology, Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Abdollah
authors.initials: A
authors.lastname: Ardebili
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Amouzandeh-Nobaveh
authors.affiliation: Department of Medical Microbiology, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran; Molecular Research Center, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Ehsanollah
authors.initials: E
authors.lastname: Ghaznavi-Rad
keywords: Antiseptics; Methicillin-resistant Staphylococcus aureus