An evaluation of the suitability of the European suspension test to reflect in vitro activity of antiseptics against clinically significant organisms

• Published in: Letters in applied microbiology Vol. 28; no. 1; pp. 7 - 12
• Main Authors: Payne, D. N., Babb, J. R., Bradley, C. R.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science, Ltd 01-01-1999; Blackwell Science
• Subjects: Anti-Infective Agents, Local - pharmacology; Antibiotics, microbial producers, chemotherapic agents, antiseptics, disinfecting agents; Applied microbiology; Biological and medical sciences; Candida albicans - drug effects; Disinfecting agents, antiseptics; Europe; Evaluation Studies as Topic; Fundamental and applied biological sciences. Psychology; Gram-Negative Bacteria - drug effects; Gram-Negative Bacterial Infections - microbiology; Gram-Positive Bacteria - drug effects; Gram-Positive Bacterial Infections - microbiology; Humans; Microbial Sensitivity Tests; Microbiology; Pseudomonas aeruginosa; Staphylococcus aureus; Europe; Pseudomonadales; In vitro; European directive; Antiseptic; Condition of use; Bacteria; Micrococcales; Pseudomonadaceae; Pseudomonas aeruginosa; Micrococcaceae; Clinical isolate; Comparative study; Staphylococcus aureus
• ISSN: 0266-8254; 1472-765X
• DOI: 10.1046/j.1365-2672.1999.00482.x

The effectiveness of four antiseptics representing soluble phenolics (Dettol), Quaternary Ammonium Compounds (QAC) (Dettol Hospital Concentrate: DHC), mixed QAC/chlorhexidine (Hibicet Hospital Concentrate: HHC) and povidone iodine (Betadine) was assessed using the proposed phase 2 step 1 European Suspension test. The in vitro activity of the antiseptics against two of the proposed challenge strains, i.e. Staphylococcus aureus and Pseudomonas aeruginosa, was compared with that of 14 problematic clinical isolates of bacteria from a range of genera, including some multiple antibiotic resistant strains, and a clinical isolate of Candida albicans. In addition to the 5 min contact time recommended in the European test, a 1 min time was included. All four products, at their recommended use dilutions and a contact time of 5 min, achieved a Microbicidal Effect (ME) log reduction of at least 5 against the majority of organisms. Differences in activity between products were more pronounced and therefore the tests more discriminatory, when the contact time was reduced to 1 min. The clinical strains were not overtly more resistant to antiseptics than the standard test strains, suggesting that the CEN test strains mimic the antiseptic susceptibility of clinical isolates.