Serratiopeptidase: a well-known metalloprotease with a new non-proteolytic activity against S. aureus biofilm

Background The use of indwelling medical devices is associated with a significant risk of infections by Staphylococcus aureus (S. aureus) which possesses a variety of virulence factors including many toxins and the ability to invade eukaryotic cells or to form biofilm on biotic and abiotic surfaces. The virulence factors above described are often related to proteins exposed on the bacterial surface. Blocking S. aureus colonization may reduce the incidence of invasive infectious diseases. Previously reports evaluated the anti-infective properties of serratiopeptidase (Spep), an extracellular metalloprotease produced by Serratia marcescens ATCC 21074 (E-15), in impairing virulence-related staphylococcal properties, such as attachment to inert surfaces and adhesion/invasion on eukaryotic cells. However, to date its mechanism of action is unknown. Methods Spep gene was PCR amplified and cloned into expression vector pET28b(+). The mutant EspepA was constructed from plasmid pET28b-Spep applying the one-step overlap extension PCR strategy. There sulting plasmids were costransformed in EcBL21(DE3) cells with the plasmid pRuW4inh1 harboring the Erwinia chrysanthemi secretion system. Bacterial pellets and supernatants were collected and analyzed by SDS-PAGE and zymography. The unambiguous identification and a detailed structure characterization of both the wild type and the mutant Spep were obtained by mass spectrometric analyses. The resultant supernatants sterilized by filtration were separately used to condition biofilm formation of S. aureus. Quantification was based on crystal violet method. Results In this work we constructed Spep mutant by substituting the glutamic acid in the catalytic site with a residue of alanine. In this manner we were able to evaluate the anti-biofilm activity of Spep mutant in absence of proteolytic activity. As expected, this mutant did not display protease activity but it retained its anti-biofilm properties, suggesting that this action is independent by enzymatic activity. Conclusions New knowledge obtained from data reported in this paper calls attention to a novel mechanism of action of Spep. This protein could be developed as a potential “antipathogenic agent” capable to impair the ability of S. aureus to form biofilm on prostheses, catheters and medical devices, exploiting a mechanism different from the proteolytic activity

Scalp psoriasis: report of efficient treatment with secukinumab

Background: Psoriasis is a chronic inflammatory skin disease affecting 2-3% of the population in the world. The scalp is the most common, and frequently the first site of disease involvement. Occasionally it may be the only localization of psoriasis. Objective: Treatment of scalp psoriasis is often unsatisfactory, due to limited available topical therapy and reduced efficacy of some systemic drugs. Biologic therapies are recommended for severe psoriasis, resistant to topical treatment, but evidence from randomized, controlled studies is lacking regarding effectiveness on scalp-localized lesions. The aim of this paper is to show our experience on the efficacy of secukinumab on scalp psoriasis involvement. Methods: Adult patients with moderate to severe plaque psoriasis located in the scalp, who were eligible for biological therapy were selected for treatment with secukinumab. Results and Conclusion: Several clinical studies have shown the efficacy of secukinumab on plaque psoriasis, and some encouraging experience suggest the use in difficult sites such as the scalp; this article reports effective treatment with secukinumab of a series of patients with plaque and scalp psoriasis

Timing of quality of life improvements in psoriatic patients treated with different systemic therapies

Psoriasis impacts the quality of life (QoL) by disrupting overall health and social life. Thus, the use of a QoL evaluation item is crucial in assessing a therapeutic regimen. Also, faster improvements in QoL lead to better patient compliance, but very few studies compare psoriasis traditional and biologic therapies timing. To evaluate how much different systemic therapies improve disease severity and QoL, a retrospective analysis was performed on 56 patients. Subjects were administered different drugs and their vital statistics, psoriasis area severity index (PASI) and PSOdisk were collected at baseline and after 30 days. We found a moderate correlation between PASI and PSOdisk score with (r): .62. In terms of clinical scores improvement after 30 days, Ustekinumab turned out to be the fastest therapy available, while cyclosporine, among the systemic therapies available, appeared as highly competitive if not better than other biologic therapies