COMPARISON OF THE STAND-ALONE ANTIMICROBIAL EFFICACY OF THREE DUAL DISINFECTION MULTIPURPOSE DISINFECTING SOLUTIONS

Title COMPARISON OF THE STAND-ALONE ANTIMICROBIAL EFFICACY OF THREE DUAL DISINFECTION MULTIPURPOSE DISINFECTING SOLUTIONS
Author, Co-Author Hua Zhu, Wu Duojia, Rani Bandara, Mark Willcox
Topic
Year
2011
Day
Program Number
115587
Room
Amphitheater
Affiliation
Brien Holden Vision Institute
Abstract PURPOSE: To compare the disinfection efficacy of multipurpose disinfecting solutions (MPDS) containing either polyquaternium-1 and alexidine dihydrochloride (RevitaLens Ocutec®; PQ/Alexidine), or PQ and polyaminopropyl biguanide (Biotrue™; PQ/PHMB), or PQ and myristamidopropyl dimethylamine (OPTI-FREE® RepleniSH®; PQ/ALDOX) using laboratory and clinical bacterial, fungal and amoebal isolates.

METHODS: The antimicrobial efficacy of the MPDS was measured using the ISO 14729 Stand Alone test. The activity against Acanthamoeba was measured using a modified version of this test. The standard ATCC isolates of bacteria and fungi were used along with 2 clinical isolates of Staphylococcus aureus, 8 clinical isolates of Gram-negative bacilli and 2 clinical isolates of fungi. Acanthamoeba polyphaga ROS and Acanthamoeba castellanii trophozoites and cysts were used.

RESULTS: All 3 MPDS passed the Stand Alone criteria. However, there were differences in the ability of the MPDS to kill the clinical isolates. PQ/Alexidine and PQ/PHMB were significantly better at killing the 2 clinical staphylococci (>5log reduction ) than PQ/ALDOX (p<0.0001). PQ/Alexidine was significantly better at killing clinical isolates of Pseudomonas aeruginosa (>5 log reduction) than either PQ/PHMB (p<0.05) or PQ/ALDOX (<0.0001). PQ/Alexidine and PQ/PHMB were better at killing Serratia marcescens clinical isolates (≥ 5 log reduction) than PQ/ALDOX. PQ/ALDOX was unable to kill more than 1 log of Delftia acidovorans, Stenotrophomonas maltophilia or Candida albicans whereas PQ/Alexidine and PQ/PHMB gave >5 log reduction (p<0.001). PQ/Alexidine was significantly better at killing cysts of both Acanthamoeba strains (≥1.8 log reduction) than either PQ/PHMB or PQ/ALDOX (≤1 log reduction; p=0.0001).

CONCLUSIONS: The combination of PQ/Alexidine was better at killing many clinical isolates of Gram-negative bacteria and fungi than the combination of PQ/ALDOX. PQ/Alexidine had significantly more anti-acanthamoebal cyst activity than either PQ/ALDOX or PQ/PHMB.
Affiliation of Co-Authors Brien Holden Vision Institute, Brien Holden Vision Institute, University of New South Wales, School of Optometry and Vision Science
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