Natascia Bruni
Istituto Farmaceutico Candioli, Italy
Title: In vitro bactericidal activity of lactoferricin and other enzymes on bacteria selected from dogs with pyoderma
Biography
Biography: Natascia Bruni
Abstract
Lactoferricin (LFcin) is a peptide with antimicrobial activity against microorganisms such as Gram negative and positive bacteria,
including some antibiotic-resistant pathogens. Others enzymes like dextrozyme, alcalase and amylase may be associated to the
LFcin to enhance its antimicrobial action. The aim of this study was to evaluate the in vitro activity of LFcin associations with
dextrozyme (LFD), alkalase (LFL) and amylase (LFM) against Staphylococcus pseudintermedius, Escherichia coli, Proteus vulgaris
and Pseudomonas aeruginosa strains isolated from dogs with pyoderma. The evaluation was performed using minimum inhibitory
concentrations with a microtiter plate dilution method starting by an LFcin/enzymes solution at 11%. The bacterial inoculums in
log-phase growth were prepared in brain heart infusion broth (BHI) with a turbidity of 0.5 McFarland, corresponding to 102 to 103
cells/ml. Dilutions in BHI at 2:1 (7.5%), 1:1 (5.5%), 1:2 (3.7%) and 1:5 (1.8%) were used for each bacteria. Negative and positive
controls were included. All the wells were incubated 10 μl on blood agar at 37 °C for 48 hours to confirm the bacterial inhibition. The
associations LFD and LFM showed bactericidal activity against all the isolates at 7.3%, at 5.5%, only for S. pseudintermedius at 3.7%.
The LFL showed inhibition at 3.7% for all strains and resistance at 1.8%. These results suggest that the associations of LFcin with other
enzymes improve its antimicrobial activity. The LFL exhibits in vitro bactericidal activity even against a strain of multidrug resistant
P. aeruginosa at low concentrations. LFcin and its associations should be a new topical treatment of skin infections.