An Original Use of a Bioluminescence Assay to Test the In Vitro Efficacy of Polihexanide in the Eradication of Acanthamoeba Cysts.

Purpose: Acanthamoeba keratitis is a rare ocular disease caused by Acanthamoeba spp. The current Acanthamoeba keratitis treatments consist of unlicensed drugs, most commonly polihexanide (PHMB), a biguanide derivative, either as monotherapy or combined with a diamidine. The main purpose of this study was to develop an in vitro bioluminescence assay able to differentiate the antiamoebic activity of PHMB concentrations (0.

Susceptibility of methicillin-resistant Staphylococci clinical isolates to netilmicin and other antibiotics commonly used in ophthalmic therapy.

Purpose: The aim of this study was to test the activity of selected antimicrobial agents commonly used in the treatment of ocular infections against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) isolates.

Methods: A total of 43 staphylococci from respiratory tract and ocular infections were characterized for methicillin resistance using the Epsilometer test (E-test), the polymerase chain reaction for mecA gene detection and the PBP2' latex agglutination test. A perfect agreement among them was observed in 20 isolates (8 MRSA and 12 MRSE) which were then employed in the susceptibility test by using the agar disk diffusion test (NCCLS).

In vitro activity of carvacrol against staphylococcal preformed biofilm by liquid and vapour contact.

Carvacrol is an important component of essential oils and recently has attracted much attention as a result of its biological properties, such as a wide spectrum of antimicrobial activity. The aim of this study was to evaluate the effect of carvacrol in liquid and vapour phase on preformed biofilms of Staphylococcus aureus and Staphylococcus epidermidis by determining biofilm biomass and cultivable cell numbers, and by using epifluorescence and scanning electron microscopy. Carvacrol was able to reduce biofilm biomass and cell viability more effectively when used with liquid contact rather than with vapour phase.

Effects of oregano, carvacrol and thymol on Staphylococcus aureus and Staphylococcus epidermidis biofilms.

The aim of this study was to evaluate the effect of oregano essential oil, carvacrol and thymol on biofilm-grown Staphylococcus aureus and Staphylococcus epidermidis strains, as well as the effects of the oils on biofilm formation. For most of the S. aureus (n=6) and S.

Epigallocatechin gallate inhibits biofilm formation by ocular staphylococcal isolates.

Epigallocatechin gallate (EGCg), the main polyphenol component of green tea, has several antibacterial properties. Here we show that sub-MICs of EGCg appear to decrease slime production, therefore inhibiting biofilm formation by ocular staphylococcal isolates previously characterized for the presence of ica genes by the Congo red agar plate assay and for adhesion to microtiter plates.

Epigallocatechin-gallate enhances the activity of tetracycline in staphylococci by inhibiting its efflux from bacterial cells.

Epigallocatechin-gallate (EGCg), the major catechin present in green tea extracts, has been shown to have several antibacterial activities, limiting bacterial growth and invasion and acting in synergy with beta-lactam antibiotics. In this article, we report that EGCg at doses half and below its calculated MIC of 100 microg/ml, is able to reverse tetracycline resistance in staphylococcal isolates expressing the specific efflux pump Tet(K) and appears to improve the MICs of tetracycline for susceptible staphylococcal isolates as well. The visible effect of EGCg is an increased accumulation of tetracycline inside bacterial cells.

Susceptibility of methicillin-resistant staphylococci to oregano essential oil, carvacrol and thymol.

The aim of this study was to evaluate the susceptibility of methicillin-susceptible and methicillin-resistant staphylococci (MSS, MRS) to oregano essential oil, carvacrol and thymol. The commercial aerial parts of Origanum vulgare L. were hydrodistilled and the essential oil analysed by gas- chromatography/electron impact mass spectrometry.