• What is a biofilm?
An aggregate of bacterial cells encased in an extracellular matrix of polymeric substances that protect bacteria from
antibiotics, chemical products, and the body's immune system. It can form on medical
instruments and devices, as well as on body tissues.
This creates resistance to antibiotic therapy: bacteria embedded in a biofilm can be 100 to
1000 times more resistant compared to "free" bacteria.
Some bacterial species can produce biofilms. These include Staphylococcus pseudintermedius, Pseudomonas
aeruginosa (especially in otitis in dogs, Figs. 1 and 2), Proteus mirabilis, Escherichia coli.
In the case of yeasts, Malassezia spp. can also form biofilms, particularly in cases of seborrheic dermatitis in
dogs.
Therapy: topical therapy is one of the most innovative and includes not only the use of effective products but also
their combination to synergize their activity.
• TRIS-EDTA (Ethylenediaminetetraacetic acid):
Has a bactericidal effect on non-growing cells in the biofilm (Ciofu et al, 2017). The combination of EDTA with Tromethamine (TRIS)
leads to damage to the cell wall and increases penetration through the cell membrane. It is well tolerated, not
ototoxic, and synergistically interacts with chlorhexidine (Guardabassi et al, 2010). A recently conducted in vitro experiment showed
that Tris-EDTA is a very effective aid in the treatment of chronic Pseudomonas otitis with potential biofilm presence
when combined with antibiotics (Pye et al, 2014).
• NAC (N-Acetyl Cysteine):
The N-acetylated derivative of the amino acid cysteine has a mucolytic action. By disrupting the production of
exopolysaccharides (EPS), it weakens the matrix EPS. NAC has been used in eight clinical studies as
adjunctive therapy to disrupt existing biofilm and prevent its formation, showing excellent
efficacy and a safe profile. The combination of Tris-EDTA and NAC, applied to the skin or in the ear before applying
topical products such as chlorhexidine, antibiotics, and synthetic antimicrobial peptides allows for increasing
biofilm permeability and its subsequent disintegration. This effectively overcomes the problem of
resistance in the classical antibacterial therapeutic approach.
Instructions for use:
1. Press down on the top of the bottle until
the capsule breaks completely.
2. Shake the vial.
3. With the syringe provided in the package, withdraw
the necessary amount, following the instructions of a veterinarian.
In the ear canal: rinse thoroughly and massage the base of the ear.
On the skin: rinse until the affected area is thoroughly wet.
Repeat treatment as needed or follow
the instructions of a veterinarian.
