Related Experiment Video
Updated: Jul 12, 2026
Therapeutic Effectiveness of a Dietary Supplement for Management of Halitosis in Dogs
Published on: July 6, 2015
In vitro activity of lactoferricin solution against Malassezia pachydermatis from otitis externa in dogs and cats
Antonio Corona1, Antonella Vercelli1, Natascia Bruni2
1Città di Torino" Veterinary Clinic, c.so Traiano 99/c, 10135 Turin, Italy.
Background:
Malassezia pachydermatis is a commensal organism of the skin, yet it may induce dermatitis and/or otitis. Lactoferricin (Lfcin) is an antimicrobial peptide obtained by the pepsin-mediated digestion of lactoferrin, a multifunctional innate-defence milk protein. The antibacterial activity of Lfcin is thought to cause alteration of bacterial membrane permeability, thus inducing cell death.
Objectives:
The aim of this study was to evaluate in vitro antifungal activity of different dilutions of Lfcin solution against M. pachydermatis strains isolated from ears of dogs and cats with otitis externa.
Methods And Materials:
Fifty clinical Malassezia isolates from 40 dogs and 10 cats were tested. A dilution method in microtitre plates was used starting with a 20% Lfcin water solution. The different dilutions were 2:1 (13.3%), 1:1 (10%), 1:2 (6.7%), 1:5 (3.3%) and 1:10 (1.8%). Results were expressed as the value at which the growth of 50% (minimal fungicidal concentration MFC50 ) and 90% (MFC90 ) of yeast cells was inhibited.
Results:
All strains showed susceptibility to 20% Lfcin solution (100%). With 1:5 and 1:10 dilutions corresponding to 3.3% and 1.8% Lfcin solutions, all strains showed resistance. The MFC50 and MFC90 values were observed at 13.3% and 20% Lfcin solutions.
Conclusions And Clinical Relevance:
The results indicated that Lfcin solution exhibits the antimicrobial activity specific to antimicrobial peptides. In particular, the 20% solution can be effective in killing M. pachydermatis isolated strains. Some susceptibilities also are evident at lower concentrations of ≤6.7% for four strains.
Insights
Lactoferricin (Lfcin) shows antifungal activity against Malassezia pachydermatis, a common cause of otitis externa in pets. A 20% Lfcin solution effectively inhibited yeast growth, suggesting its potential therapeutic use.
Area of Science:
- Veterinary Mycology
- Antimicrobial Peptides
- Dermatology
Background:
- Malassezia pachydermatis is a yeast that can cause skin and ear infections (otitis externa) in dogs and cats.
- Lactoferricin (Lfcin) is a peptide derived from lactoferrin with known antimicrobial properties.
Purpose of the Study:
- To evaluate the in vitro antifungal effectiveness of various Lactoferricin dilutions against Malassezia pachydermatis.
- To determine the minimal fungicidal concentrations (MFC50 and MFC90) of Lfcin against clinical isolates.
Main Methods:
- Fifty clinical isolates of Malassezia pachydermatis from dogs and cats with otitis externa were tested.
- A microtitre plate dilution method was employed, starting with a 20% Lfcin solution and creating serial dilutions.
- Fungicidal activity was assessed by determining the minimal fungicidal concentration (MFC50 and MFC90).
Main Results:
- All Malassezia strains were susceptible to the 20% Lfcin solution.
- Resistance was observed at lower concentrations (1.8% and 3.3% Lfcin).
- Effective fungicidal activity (MFC50 and MFC90) was achieved with 13.3% and 20% Lfcin solutions.
Conclusions:
- Lactoferricin solution demonstrates potent in vitro antifungal activity against Malassezia pachydermatis.
- A 20% Lfcin solution is effective in eliminating Malassezia strains, indicating its potential for treating otitis externa.
- Some activity was noted at lower concentrations (≤6.7%) for a subset of strains.
