Antimicrobial and antistaphylococcal biofilm activity from the sea urchin Paracentrotus lividus.

AIMS: 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. METHODS AND 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. SIGNIFICANCE AND IMPACT OF THE STUDY: 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.

[Postoperative pain in laparoscopic surgery]. / Il dolore post-operatorio in chirurgia laparoscopica.

The occurrence of post-operative pain, although less severe and frequent than in open surgery, may affect length of hospital stay and early return to normal activity in some patients operated on with laparoscopic surgery. Although several pathogenetic factors have been indicated in the literature, the mechanism responsible for post-operative pain after laparoscopy; still remains unclear. In this study the Authors evaluated post-operative pain in 90 patients submitted to laparoscopic cholecystectomy and correlated it to the length of operation, endoabdominal CO2 pressure maintained during surgery, and use of local anesthesia instilled din the liver bed and in the sites of introduction of trocars. Measuring post-operative pain by means of a modified Scott-Huskisson Visual Analogue Scale, no difference in the severity of the pain was noted in the two subgroups of patients with a length of operation inferior or superior to 60 minutes, respectively. Conversely, a statistical significant difference (p = 0.04 and p = 0.049 according to Fisher exact test and Pearson test, respectively) was observed evaluating the use of local anesthesia and the level of CO2 endoabdominal pressure, with less pain in patients whose pressure was maintained under 10 mmHg and in patients treated with instillation of local anesthetic drugs in the liver bed and in the sites of introduction of trocars.

Detection and localisation of disulphide bonds in a synthetic peptide reproducing the sequence 1-30 of Par j 1.0101 by electrospray ionisation mass spectrometry.

The structural characterisation of a synthetic peptide reproducing the sequence 1-30 of Par j 1.0101, a major allergenic protein present in the pollen of Parietaria judaica, by combined use of chemical and enzymatic cleavage, reversed-phase high-performance liquid chromatography and electrospray ionisation mass spectrometry (ESI-MS), is described. Direct ESI-MS of the synthetic peptide after reaction with methyl iodide showed that the product is a mixture of two peptides: one form in which two out of the four cysteine residues present in the sequence are oxidised and a minor amount of another form in which all the cysteines are fully reduced. It was ascertained, using the combined procedure indicated above and without prior separation of the two species, that the disulphide bond in the partially oxidised form is located between cysteines 29 and 30. These results show the usefulness of this approach for characterising synthetic peptides containing multiple cysteine residues in the sequence.