title: Effect of multipurpose solutions against Acinetobacter carrying QAC genes.
abstract: OBJECTIVE
  Acinetobacter has low virulence but causes infections in subjects with reduced immunity. It has been reported in ocular infections including those of patients using contact lenses. Treatment is difficult because Acinetobacter is frequently multidrug resistant. Antibiotic-resistant strains frequently also harbor genes for antiseptic resistance (quaternary ammonium compound [QAC]) genes. Because Acinetobacter is part of the normal flora, it may contaminate contact lens and accessories. This study aims to investigate carriage rates of QAC genes in household and clinical isolates of Acinetobacter and to determine the effectiveness of two multipurpose solutions (MPSs) for soft lenses against organisms carrying QAC genes.
  
  
  METHODS
  DNA was extracted from 11 bathroom isolates and 15 clinical isolates and amplified by polymerase chain reaction to determine the presence of qacEΔ1. Gene-positive and gene-negative control strains were used to challenge the two MPSs, and minimum inhibitory concentrations (MICs) of these organisms to benzalkonium chloride and chlorhexidine gluconate were determined.
  
  
  RESULTS
  More than 90% of isolates carried qacEΔ1. The MICs of clinical isolates were higher than those of isolates of bathrooms. Both MPSs were able to produce a 3-log reduction in the numbers of all isolates.
  
  
  CONCLUSIONS
  Although most isolates carried qacEΔ1 and elevated MICs to benzalkonium chloride and chlorhexidine gluconate were observed, all were susceptible to both MPSs tested. However, if there were to be poor compliance with care procedures, it is probable that such organisms could survive in the presence of diluted or expired solutions.
authors: *DPhil, FIBMS †BSc, MLT ‡MD §PhD, FAAO Department of Health Technology and Informatics (MVB, JC), and School of Optometry (G-sS, PC), The Hong Kong Polytechnic University, Hong Kong SAR, China.
authors: Maureen V
authors: MV
authors: Boost
authors: Jessica
authors: J
authors: Chan
authors: Guang-sen
authors: GS
authors: Shi
authors: Pauline
authors: P
authors: Cho
mesh_terms: D000150:Acinetobacter / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D001548:Benzalkonium Compounds / Q000494:pharmacology*; D002710:Chlorhexidine / Q000494:pharmacology*; D003263:Contact Lenses, Hydrophilic / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction
chemical_list: D000891:Anti-Infective Agents, Local; D001426:Bacterial Proteins; D001548:Benzalkonium Compounds; D004269:DNA, Bacterial; D002710:Chlorhexidine