Related Experiment Video
Updated: May 30, 2026
08:54
Broth Microdilution In Vitro Screening: An Easy and Fast Method to Detect New Antifungal Compounds
Published on: February 14, 2018
Comparative in vitro efficacy of antimicrobial shampoos: a pilot study
Rebecca Young1, Laura Buckley, Neil McEwan
1Department of Infection Biology, School of Veterinary Science, The University of Liverpool, Leahurst Campus, Neston, UK.
Veterinary Dermatology
|July 23, 2011
Summary
Chlorhexidine shampoos demonstrated superior antimicrobial efficacy against various bacteria, including meticillin-resistant Staphylococcus pseudintermedius (MRSP). Benzoyl peroxide and ethyl lactate showed moderate effectiveness, while chloroxylenol and acetic acid-boric acid were less effective overall.
Area of Science:
- Veterinary Dermatology
- Antimicrobial Agents
Background:
- Bacterial and fungal skin infections are common in veterinary medicine.
- The emergence of antimicrobial resistance necessitates evaluation of topical treatments.
- Staphylococcus pseudintermedius and Pseudomonas aeruginosa are key pathogens, alongside Malassezia pachydermatis.
Purpose of the Study:
- To compare the in vitro antimicrobial efficacy of different shampoos.
- To assess activity against key veterinary pathogens, including resistant strains.
- To determine minimal bactericidal concentrations (MBCs) for various active ingredients.
Main Methods:
- Shampoos containing chlorhexidine, benzoyl peroxide, ethyl lactate, chloroxylenol, and acetic acid-boric acid were tested.
- Microorganisms included meticillin-sensitive S. pseudintermedius (MSSP), meticillin-resistant S. pseudintermedius (MRSP), P. aeruginosa (PA), multidrug-resistant P. aeruginosa (MDR-PA), and M. pachydermatis.
- Incubation with diluted shampoos occurred over 10, 30, and 60 minutes, followed by microbial culture to determine MBCs.
Main Results:
- Chlorhexidine exhibited the highest efficacy, with MBCs ranging from 1:512 to 1:5,096 across all tested organisms and time points.
- Benzoyl peroxide and ethyl lactate showed moderate efficacy, with varying MBCs depending on the organism and incubation time.
- Chloroxylenol and acetic acid-boric acid were largely ineffective against bacteria but showed some activity against Malassezia.
Conclusions:
- Chlorhexidine is the most effective topical biocide among the tested shampoos.
- Meticillin-resistant S. pseudintermedius (MRSP) and multidrug-resistant P. aeruginosa (MDR-PA) showed susceptibility comparable to their antibiotic-sensitive counterparts.
- Further in vivo studies with larger isolate numbers are recommended to confirm these findings.
