Aims:  The in vitro activity of some essential oils (EO) (thyme red, fennel, clove, pine, sage, lemon balm and lavender) against clinical and environmental fungal strains was determined. Methods and Results:  The minimal inhibitory concentrations were determined by a microdilution method in RPMI 1640 and by a vapour contact assay. The composition of oils was analysed by gas chromatography (GC) and GC/mass spectrometry. The results indicated that the oils antifungal activity depended on the experimental assay used. The inhibiting effects of EO in vapour phase were generally higher than those in liquid state. According to both methods thyme red and clove were found to be the oils with the widest spectrum of activity against all fungi tested. Conclusions:  Despite the differences between the two methods, our results demonstrate that some EO are very active on dermatophytes and dematiaceous fungi. However, more data will be necessary to confirm this good in vitro efficacy. Significance and Impact of the Study:  This study could identify candidates of EO for developing alternative methods to control environmental and clinically undesirable filamentous fungi.

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Eye drops are widely accepted as formulations for targeting the anterior segment notwithstanding their limitations in terms of bioavailability. The unique structure of the eye requires specially-designed formulations able to favor the pharmacokinetic profile of administered drugs, mainly minimizing the influence of ocular barriers. Nanotechnology-based delivery systems lead to significant technological and therapeutical advantages in ophthalmic therapy. The aim of the present study was to determine whether tobramycin as ion-pair incorporated in mucoadhesive Solid Lipid Nanoparticles (SLN) reaches the inner parts of the eye favoring drug activity. After technological characterization of the tobramycin entrapped SLN formulation (Tobra-SLN), a pharmacokinetic study in rabbits after topical instillation and intravenous administration of the formulation has been carried out. In addition, the intracellular activity of Tobra-SLN formulation against phagocytosed Pseudomonas aeruginosa was investigated. The SLN were spherical in shape, and showed a hydrodynamic diameter of about 80nm, a negative zeta potential (-25.7mV) with a polydispersity index of 0.15, representative of a colloidal dispersion with high quality, characterized by an unimodal relatively narrow size distribution. As demonstrated by FTIR and DSC, tobramycin ion-pair could be concentrated into lipid inner core of SLN, without interaction with the stearic acid, thus promoting a slow and constant drug release profile in the dissolution medium. Surprisingly, the drug concentration was significantly higher in all ocular tissues after ocular and intravenous administration of Tobra-SLN formulation with respect to reference formulations and only Tobra-SLN allowed the penetration of drug into retina. Furthermore, the use of Tobra-SLN resulted in both higher intraphagocytic antibiotic concentrations in polymorphonuclear granulocytes and greater bactericidal activity against intracellular Pseudomonas aeruginosa, probably due to the ability of Tobra-SLN to penetrate either into phagocytic cells, or alternatively to cross bacterial barrier. The present study broadens the knowledge on the use of SLN as carriers for ocular drug delivery to the posterior chamber and might open new avenues for treatment of ocular infections, representing a strategy to overcome the microbial resistance.

BackgroundCryptococcal infections, besides being a problem for immunocompromised patients, are occasionally being a problem for immunocompetent patients. In addition, the lower susceptibility of this yeast to azoles is a growing problem in health care. To date, there are very few molecules with any activity towards Cryptococcus neoformans, leading to heightened interest in finding new alternatives or adjuvants to conventional drugs for the treatment of mycosis caused by this yeast. Since the essential oils (EOs) are considered as a potential rich source of bioactive antimicrobial compounds, we evaluated the antifungal activity of Origanum vulgare (oregano), Pinus sylvestris (pine), and Thymus vulgaris (thyme red) EOs, and their components (α-pinene, carvacrol, thymol) compared with fluconazole, itraconazole, and voriconazole, against C.neoformans clinical strains. Then, we investigated the effect of EOs and components in combination with itraconazole.MethodsEO composition was analysed by Gas chromatography-mass spectrometry (GC-MS). A broth microdilution method was used to evaluate the susceptibility of C.neoformans to azoles, EOs and components. Checkerboard tests, isobolograms and time-kill assays were carried out for combination studies.ResultsSix C.neoformans isolates were susceptible to azoles, while one C.neoformans exhibited a reduced susceptibility to all tested azole drugs. All EOs exerted a good inhibitory activity against all C.neoformans strains. Pine EO was the most effective. Among components, thymol exerted the most remarkable activity. By checkerboard testing and isobolographic analysis, combinations of itraconazole with oregano, pine, or thyme EOs, and carvacrol were found to be synergistic (FICI≤0.5) against azole susceptible C.neoformans. Regarding the azole not susceptible C.neoformans strain, the synergistic effect with itraconazole was observed with thyme EO (chemotype: thymol 26.52%; carvacrol 7.85%), and carvacrol. Time-kill assays confirmed the synergistic effects of itraconazole and oregano or thyme EO against azole susceptible C.neoformans. Binary mixtures of itraconazole/thyme EO or carvacrol yielded additive effects on the azole not susceptible C.neoformans.ConclusionsOur findings highlight the potential effectiveness of thyme, oregano EOs, and carvacrol as natural and cost-effective adjuvants when used in combination with itraconazole. Identification of EOs exerting these effects could be one of the feasible ways to overcome drug resistance, reducing drug concentration and side effects.

Intestinal colonization by lactobacilli is suggested to be a prerequisite to normal mucosal immune functions. An inadequate level of lactobacilli may be involved in appearance of allergic disease of which, infantile colic, is often considered an early clinical manifestation. The aim of the study is to evaluate intestinal lactobacilli in breast-fed infants with infantile colic and healthy infants. Fifty-six breast-fed infants, aged 15-60 days were enrolled in the study and divided into two groups: colicky (30 cases) and healthy (26 cases) according to Wessel's criteria. Stool samples were collected, diluted and cultured on selective media. The colonies were counted, reported as colony forming unit (cfu) per gram of faeces and identified by biochemical methods. Different colonization patterns of lactobacilli were found among colicky and healthy infants. Lactobacillus brevis (4.34 x 10(8) cfu/g) and L. lactis lactis (2.51 x 10(7) cfu/g) were found only in colicky infants while L. acidophilus (2.41 x 10(7) cfu/g) was found only in healthy infants. Lactobacillus brevis and L. lactis lactis might be involved in the pathogenesis of infantile colic increasing meteorism and abdominal distension. Further studies are required to understand how the observed differences may be involved in the pathogenesis of this common disorder.