Antimicrobial and antistaphylococcal biofilm activity from the sea urchin Paracentrotus lividus.
OBJECTIVE
Staphylococcal biofilm-associated infections are resistant to conventional antibiotics. Consequently, new agents are needed to treat them. With this aim, we focused on the effector cells (coelomocytes) of the sea urchin Paracentrotus lividus immune system.


RESULTS
We tested the activity of the 5-kDa peptide fraction of the cytosol from coelomocytes (5-CC) against a group of Gram-positive, Gram-negative bacteria and fungi. We determined minimal inhibitory concentrations (MICs) ranging from 253.7 to 15.8 mg ml(-1). We observed an inhibitory activity and antibiofilm properties of 5-CC against staphylococcal biofilms of reference strains Staphylococcus epidermidis DSM 3269 and Staphylococcus aureus ATCC 29213. The antimicrobial efficacy of 5-CC against the biofilms of clinical strain Staph. epidermidis 1457 was also tested using live/dead staining in combination with confocal laser scanning microscopy. At a sub-MIC concentration (31 x 7 mg ml(-1)) of 5-CC the formation of young (6-h old) and mature (24-h old) staphylococcal biofilms was inhibited.


CONCLUSIONS
The biological activity of 5-CC could be attributed to three peptides belonging to the sequence segment 9-41 of a beta-thymosin of P. lividus.


CONCLUSIONS
The effector cells of P. lividus represent an interesting source of marine invertebrates-derived antimicrobial agents in the development of new strategies to treat staphylococcal biofilms.
Schillaci
D
D
Department of Medicinal Chemistry and Technology, Università degli Studi di Palermo, Via Archirafi, 32 - 90123 Palermo, Italy. dschill@unipa.it
Arizza
V
V
Parrinello
N
N
Di Stefano
V
V
Fanara
S
S
Muccilli
V
V
Cunsolo
V
V
Haagensen
J J A
JJ
Molin
S
S
D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects*; D002458:Cell Fractionation; D003600:Cytosol / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D018613:Microscopy, Confocal; D047328:Paracentrotus / Q000166:cytology* / Q000276:immunology / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D013194:Staining and Labeling; D013203:Staphylococcal Infections / Q000517:prevention & control; D013211:Staphylococcus aureus / Q000187:drug effects*; D013212:Staphylococcus epidermidis / Q000187:drug effects*; D013947:Thymosin / Q000737:chemistry / Q000235:genetics
D000890:Anti-Infective Agents; D010455:Peptides; D013947:Thymosin