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© 2017 Wiley Periodicals, Inc. Contact lens (CL) wear is a risk factor for development of microbial keratitis, a vision threatening infection of the eye. Adverse events associated with colonization of lenses, especially by the multi-drug resistant and biofilm forming bacterium Pseudomonas aeruginosa remain a major safety issue. Therefore, novel strategies and compounds to reduce the onset of CL-associated ocular infections are needed. Recently, the activity of the frog skin-derived antimicrobial peptide Esc(1-21) and its diastereomer Esc(1-21)-1c was evaluated against both planktonic and sessile forms of this pathogen. Furthermore, Esc(1-21) was found to significantly reduce the severity of P. aeruginosa keratitis in a mouse model and preserve antipseudomonal activity in the presence of human basal tears. Here, we have analyzed the activity of the peptides on P. aeruginosa biofilm formed on soft CLs. Microbiological assays and scanning electron microscopy analysis indicated that the peptides were able to disrupt the bacterial biofilm, with the diastereomer having the greater efficacy (up to 85% killing vs no killing at 4 μM for some strains). Furthermore, upon covalent immobilization to the CL, the two peptides were found to cause more than four log reduction in the number of bacterial cells within 20 minutes and to reduce bacterial adhesion to the CL surface (77%-97% reduction) in 24 hours. Importantly, peptide immobilization was not toxic to mammalian cells and did not affect the lens characteristics. Overall, our data suggest that both peptides have great potential to be developed as novel pharmaceuticals for prevention and treatment of CL-associated P. aeruginosa keratitis.

In this preliminary study, a digestive method used in forensic context to extract diatoms has been applied in organs taken from ten wildlife animals belonging three species of mammals (a deer, a roe and five otters) and one species of birds (two magpies). Only four carcasses were recovered from aquatic environments (bath trough for animals, bathtub irrigation, river) and only in three cases out of ten that the cause of death was ruled out as drowning. In seven cases, the death was due to other causes: gunshot injuries for one otter, blunt trauma for a magpie, and traumatic injuries followed by motor vehicle collision in other four otters and a roe. Post-mortem examination was performed in all carcasses. The diatom test protocol was performed according to the Italian guidelines for analysis of benthic diatoms for ecological status assessment of inland waters. Five grams of lung, liver, and kidney was taken from all the animal carcasses. In some cases, additional tissue samples were also available among which brain, heart, spleen, and bone marrow. In all four cases found in water, the drowning medium was also available. Hydrogen peroxide (H2O2) digestion was performed, and identification of 21 genera of diatoms was obtained. The method proved to be suitable for the identification of diatoms in the organs of the animals drowned supporting the final diagnosis of drowning. Only in otters, all died for causes other than drowning, diatoms did not prove to be suitable for the diagnosis of drowning since their presence in the internal organs was mainly related to their main diet based on fishmeal. The authors believe that this first trial is very promising, and the results suggest that diatom test can be easily applied in forensic veterinary context.