Is Silver Addition to Scaffolds Based on Polycaprolactone Blended with Calcium Phosphates Able to Inhibit Candida albicans and Candida auris Adhesion and Biofilm Formation?

Candida spp. periprosthetic joint infections are rare but difficult-to-treat events, with a slow onset, unspecific symptoms or signs, and a significant relapse risk. Treatment with antifungals meets with little success, whereas prosthesis removal improves the outcome. In fact, Candida spp. adhere to orthopedic devices and grow forming biofilms that contribute to the persistence of this infection and relapse, and there is insufficient evidence that the use of antifungals has additional benefits for anti-biofilm activity. To date, studies on the direct antifungal activity of silver against Candida spp. are still scanty. Additionally, polycaprolactone (PCL), either pure or blended with calcium phosphate, could be a good candidate for the design of 3D scaffolds as engineered bone graft substitutes. Thus, the present research aimed to assess the antifungal and anti-biofilm activity of PCL-based constructs by the addition of antimicrobials, for instance, silver, against C. albicans and C. auris. The appearance of an inhibition halo around silver-functionalized PCL scaffolds for both C. albicans and C. auris was revealed, and a significant decrease in both adherent and planktonic yeasts further demonstrated the release of Ag+ from the 3D constructs. Due to the combined antifungal, osteoproliferative, and biodegradable properties, PCL-based 3D scaffolds enriched with silver showed good potential for bone tissue engineering and offer a promising strategy as an ideal anti-adhesive and anti-biofilm tool for the reduction in prosthetic joints of infections caused by Candida spp. by using antimicrobial molecule-targeted delivery.

Encapsulation in Oxygen-Loaded Nanobubbles Enhances the Antimicrobial Effectiveness of Photoactivated Curcumin.

In both healthcare and agriculture, antibiotic resistance is an alarming issue. Biocompatible and biodegradable ingredients (e.g., curcumin) are given priority in "green" criteria supported by the Next Generation EU platform. The solubility and stability of curcumin would be significantly improved if it were enclosed in nanobubbles (NB), and photoactivation with the correct wavelength of light can increase its antibacterial efficacy. A continuous release of curcumin over a prolonged period was provided by using innovative chitosan-shelled carriers, i.e., curcumin-containing nanobubbles (Curc-CS-NBs) and oxygen-loaded curcumin-containing nanobubbles (Curc-Oxy-CS-NBs). The results demonstrated that after photoactivation, both types of NBs exhibited increased effectiveness. For Staphylococcus aureus, the minimum inhibitory concentration (MIC) for Curc-CS-NBs remained at 46 µg/mL following photodynamic activation, whereas it drastically dropped to 12 µg/mL for Curc-Oxy-CS-NBs. Enterococcus faecalis shows a decreased MIC for Curc-CS-NB and Curc-Oxy-CS-NB (23 and 46 µg/mL, respectively). All bacterial strains were more effectively killed by NBs that had both oxygen and LED irradiation. A combination of Curc-Oxy-CS-NB and photodynamic stimulation led to a killing of microorganisms due to ROS-induced bacterial membrane leakage. This approach was particularly effective against Escherichia coli. In conclusion, this work shows that Curc-CS-NBs and Curc-Oxy-CS-exhibit extremely powerful antibacterial properties and represent a potential strategy to prevent antibiotic resistance and encourage the use of eco-friendly substitutes in agriculture and healthcare.

Design, Characterization, and Biological Activities of Erythromycin-Loaded Nanodroplets to Counteract Infected Chronic Wounds Due to Streptococcus pyogenes.

Streptococcus pyogenes causes a wide spectrum of diseases varying from mild to life threatening, despite antibiotic treatment. Nanoparticle application could facilitate the foreign pathogen fight by increasing the antimicrobial effectiveness and reducing their adverse effects. Here, we designed and produced erythromycin-loaded chitosan nanodroplets (Ery-NDs), both oxygen-free and oxygen-loaded. All ND formulations were characterized for physico-chemical parameters, drug release kinetics, and tested for biocompatibility with human keratinocytes and for their antibacterial properties or interactions with S. pyogenes. All tested NDs possessed spherical shape, small average diameter, and positive Z potential. A prolonged Ery release kinetic from Ery-NDs was demonstrated, as well as a favorable biocompatibility on human keratinocytes. Confocal microscopy images showed ND uptake and internalization by S. pyogenes starting from 3 h of incubation up to 24 h. According to cell counts, NDs displayed long-term antimicrobial efficacy against streptococci significantly counteracting their proliferation up to 24 h, thanks to the known chitosan antimicrobial properties. Intriguingly, Ery-NDs were generally more effective (104-103 log10 CFU/mL), than free-erythromycin (105 log10 CFU/mL), in the direct killing of streptococci, probably due to Ery-NDs adsorption by bacteria and prolonged release kinetics of erythromycin inside S. pyogenes cells. Based on these findings, NDs and proper Ery-NDs appear to be the most promising and skin-friendly approaches for the topical treatment of streptococcal skin infections allowing wound healing during hypoxia.

Immune Defences: A View from the Side of the Essential Oils.

The use of essential oils is increasingly being investigated among new therapeutic approaches based on medicinal plants and their extracts. With the wide use of synthetic and semi-synthetic antimicrobial drugs, the spread of drug-resistant clinical isolates has increased, and research is directed towards natural products, such as essential oils, as useful antimicrobial resources. In the context of a prospective infection, we compared the impact of essential oils and common antimicrobial agents on the microbicidal activity of human phagocytes. Here, we present the results of our decades-long investigation into the effectiveness of thyme red oil (26.52% thymol chemotype), tea tree oil (TTO), and Mentha of Pancalieri [(Mentha x piperita (Huds) var. officinalis (Sole), form rubescens (Camus) (Lamiaceae)] essential oils on human polymorphonuclear leukocytes (PMNs) capacity to kill clinical strains of Candida albicans and C. krusei when compared to three antifungal drugs used to treat candidiasis (fluconazole, anidulafungin, and caspofungin) These essential oils demonstrate antifungal drug-like and/or superior efficacy in enhancing intracellular killing by PMNs, even at subinhibitory concentrations. Our results are compared with data in the literature on essential oils and immune system interactions. This comparison would aid in identifying therapeutic solutions to the increasingly prevalent antibiotic resistance as well as filling in any remaining knowledge gaps on the bioactivity of essential oils.

In Vitro Antifungal Activity of Selected Essential Oils against Drug-Resistant Clinical Aspergillus spp. Strains.

BACKGROUND: Treatment options for aspergillosis include amphotericin B (AMB) and azole compounds, such as itraconazole (ITZ). However, serious side effects related to these antifungal agents are increasingly evident, and resistance continues to increase. Currently, a new trend in drug discovery to overcome this problem is represented by natural products from plants, or their extracts. Particularly, there is a great interest in essential oils (EOs) recognized for their antimicrobial role towards bacteria, fungi and viruses. METHODS: In this study, we evaluated the antifungal activity of eleven commercial EOs-clove, eucalyptus, geranium, hybrid lavender, lavender, lemon, lemongrass, neroli, oregano, tea tree and red red thyme-in comparison with AMB and ITZ against Aspergillus flavus, A. fumigatus and A. niger clinical isolates. Antifungal activity was determined by broth microdilution method, agar diffusion technique, fungistatic and fungicidal activities and vapor contact assay. RESULTS: Gas chromatography-mass spectrometry analysis displayed two groups of distinct biosynthetical origin: monoterpenes dominated the chemical composition of the most oils. Only two aromatic compounds (eugenol 78.91% and eugenyl acetate 11.64%) have been identified as major components in clove EO. Lemongrass EO exhibits the strongest antimicrobial activity with a minimum inhibitory concentration of 0.56 mg/mL and a minimum fungicidal concentration of 2.25-4.5 mg/mL against Aspergillus spp. strains. Clove and geranium EOs were fairly effective in inhibiting Aspergillus spp. growth. CONCLUSIONS: These results demonstrate the antimicrobial potential of some EOs and support the research of new alternatives or complementary therapies based on EOs.

Exploitation of the Antibacterial Properties of Photoactivated Curcumin as 'Green' Tool for Food Preservation.

In the search for non-chemical and green methods to counteract the bacterial contamination of foods, the use of natural substances with antimicrobial properties and light irradiation at proper light waves has been extensively investigated. In particular, the combination of both techniques, called photodynamic inactivation (PDI), is based on the fact that some natural substances act as photosensitizers, i.e., produce bioactive effects under irradiation. Notably, curcumin is a potent natural antibacterial and effective photosensitizer that is able to induce photodynamic activation in the visible light range (specifically for blue light). Some practical applications have been investigated with particular reference to food preservation from bacterial contaminants.

A Rapid and Specific Real-Time PCR Assay for the Detection of Clinically Relevant Mucorales Species.

Infections triggered by filamentous fungi placed in the order Mucorales, phylum Zygomycota, can cause serious harm to immunocompromised patients. Since there is lack of a standardized PCR (polymerase chain reaction) assay for early diagnosis of this fungal infection, this work was aimed to develop a new PCR assay able to detect the presence of Mucorales genera in clinical specimens. Here, we describe a novel diagnostic TaqMan MGB probe assay for precise and rapid detection of the most common clinical species of Mucorales. Zygomycete-specific oligonucleotides were designed to specifically amplify and bind highly conserved sequences of fungal 28S rRNA gene. Additionally, we succeeded in differentiating Mucorales species (i.e., Rhizopus, Lichtheimia, Mucor, and Rhizomucor) in artificially infected serum samples, suggesting that the quantitative capability of this real-time PCR assay could potentially optimize the diagnosis of mucormycosis.

Comparative Evaluation of Different Chitosan Species and Derivatives as Candidate Biomaterials for Oxygen-Loaded Nanodroplet Formulations to Treat Chronic Wounds.

Persistent hypoxia is a main clinical feature of chronic wounds. Intriguingly, oxygen-loaded nanodroplets (OLNDs), filled with oxygen-solving 2H,3H-decafluoropentane and shelled with polysaccharides, have been proposed as a promising tool to counteract hypoxia by releasing a clinically relevant oxygen amount in a time-sustained manner. Here, four different types of chitosan (low or medium weight (LW or MW), glycol-(G-), and methylglycol-(MG-) chitosan) were compared as candidate biopolymers for shell manufacturing. The aim of the work was to design OLND formulations with optimized physico-chemical characteristics, efficacy in oxygen release, and biocompatibility. All OLND formulations displayed spherical morphology, cationic surfaces, ≤500 nm diameters (with LW chitosan-shelled OLNDs being the smallest), high stability, good oxygen encapsulation efficiency, and prolonged oxygen release kinetics. Upon cellular internalization, LW, MW, and G-chitosan-shelled nanodroplets did not significantly affect the viability, health, or metabolic activity of human keratinocytes (HaCaT cell line). On the contrary, MG-chitosan-shelled nanodroplets showed very poor biocompatibility. Combining the physico-chemical and the biological results obtained, LW chitosan emerges as the best candidate biopolymer for future OLND application as a skin device to treat chronic wounds.

Exposure to the agricultural fungicide tebuconazole promotes Aspergillus fumigatus cross-resistance to clinical azoles.

Resistance to clinical triazoles in Aspergillus fumigatus is a growing concern for individuals at high risk of Aspergillus infection. Two triazole resistance selection routes are currently being investigated: one occurring in triazole-treated patients in healthcare settings, and the second taking place in the environment due to the widespread use of agricultural triazoles. This study aimed to assess the ability of agricultural azoles to promote cross-resistance to clinical azoles in A. fumigatus. Five A. fumigatus isolates susceptible to clinical azoles were exposed to the triazole 14α-demethylase inhibitor, tebuconazole (TBC), and then antifungal susceptibility tests for voriconazole, itraconazole, posaconazole and isavuconazole were performed. Under TBC selection pressure, all A. fumigatus isolates exhibited resistance to clinical triazoles. However, only two displayed a multiresistant phenotype to clinical azoles. TBC exposure was also associated with delayed conidia formation and progressive absence of conidiation. Noteworthy, no TBC-exposed clones harbored TR34/L98H mutation, as judged by real-time PCR assays. The observation that TBC exposure promotes cross-resistance to clinical triazoles warrants careful and thorough assessment of the human health risk associated with agricultural azoles. The absence of TR34/L98H mutation in cross-resistant A. fumigatus isolates suggests that other cyp51A mutations may be involved in clinical azole cross-resistance.

Antifungal Activity of Melaleuca alternifolia Essential Oil (TTO) and Its Synergy with Itraconazole or Ketoconazole against Trichophyton rubrum.

Over the past 20-30 years, Trichophyton rubrum represented the most widespread dermatophyte with a prevalence accounting for 70% of dermatophytosis. The treatment for cutaneous infections caused by Trichophyton spp. are imidazoles (ketoconazole (KTZ)) and triazoles (itraconazole (ITZ)). T. rubrum can develop resistance to azoles after prolonged exposure to subinhibitory concentrations resulting in therapeutic failures and chronic infections. These problems have stimulated the search for therapeutic alternatives, including essential oils, and their potential use in combination with conventional antifungals. The purpose of this study was to evaluate the antifungal activity of tea tree oil (TTO) (Melaleuca alternifolia essential oil) and the main components against T. rubrum and to assess whether TTO in association with KTZ/ITZ as reference drugs improves the antifungal activity of these drugs. We used a terpinen-4-ol chemotype (35.88%) TTO, and its antifungal properties were evaluated by minimum inhibitory and minimum fungicidal concentrations in accordance with the CLSI guidelines. The interaction between TTO and azoles was evaluated through the checkerboard and isobologram methods. The results demonstrated both the fungicide activity of TTO on T. rubrum and the synergism when it was used in combination with azoles. Therefore, this mixture may reduce the minimum effective dose of azole required and minimize the side effects of the therapy. Synergy activity offered a promise for combination topical treatment for superficial mycoses.

The Inhibition of Non-albicans Candida Species and Uncommon Yeast Pathogens by Selected Essential Oils and Their Major Compounds.

The epidemiology of yeast infections and resistance to available antifungal drugs are rapidly increasing, and non-albicans Candida species and rare yeast species are increasingly emerging as major opportunistic pathogens. In order to identify new strategies to counter the threat of antimicrobial resistant microorganisms, essential oils (EOs) have become an important potential in the treatment of fungal infections. EOs and their bioactive pure compounds have been found to exhibit a wide range of remarkable biological activities. We investigated the in vitro antifungal activity of nine commercial EOs such as Thymus vulgaris (thyme red), Origanum vulgare (oregano), Lavandula vera (lavender), Pinus sylvestris (pine), Foeniculum vulgare (fennel), Melissa officinalis (lemon balm), Salvia officinalis (sage), Eugenia caryophyllata (clove) and Pelargonium asperum (geranium), and some of their main components (α-pinene, carvacrol, citronellal, eugenol, γ-terpinene, linalool, linalylacetate, terpinen-4-ol, thymol) against non-albicans Candida strains and uncommon yeasts. The EOs were analyzed by GC-MS, and their antifungal properties were evaluated by minimum inhibitory concentration and minimum fungicidal concentration parameters, in accordance with CLSI guidelines, with some modifications for EOs. Pine exhibited strong antifungal activity against the selected non-albicans Candida isolates and uncommon yeasts. In addition, lemon balm EOs and α-pinene exhibited strong antifungal activity against the selected non-albicans Candida yeasts. Thymol inhibited the growth of all uncommon yeasts. These data showed a promising potential application of EOs as natural adjuvant for management of infections by emerging non-albicans Candida species and uncommon pathogenic yeasts.

A case report of tinea capitis in infant in first year of life.

BACKGROUND: Tinea capitis is a cutaneous fungal infection common among 3 to 7 year old children but it is rare in the first year of life. CASE PRESENTATION: We present a case of a 12-month-old infant with erythematous scalp lesions combined with hair loss. He was suspected of dermatophytosis and mycological analysis of all suspected lesions was performed. Clinical features and culture results confirmed tinea capitis caused by Microsporum canis. The infant patient was treated with griseofulvin for 2 months. However, 15 days later at the end of treatment he presented with a single vesicle positive for M. canis. Griseofulvin therapy continued for another month. After 3 months of follow-up, no recurrence was observed. CONCLUSIONS: In infant, sometimes tinea capitis is misdiagnosed and underreported because it is similar to other scalp pathologies. Therefore, if erythematous scalp lesions are present, they must be examined from a mycological point of view to inform the differential diagnosis. Once diagnosed, treatment of tinea capitis can pose a dilemma because different factors may influence the choice between equally effective therapies (i.e. safety, age, formulation, cost). This case report suggests that it is important to establish an accurate diagnosis and  treatment for this dermatophytosis to avoid recurrences or therapeutic failures, especially in infants.

Enhanced Killing of Candida krusei by Polymorphonuclear Leucocytes in the Presence of Subinhibitory Concentrations of Melaleuca alternifolia and "Mentha of Pancalieri" Essential Oils.

The aim of this study was to evaluate the influence of tea tree oil (TTO) and "Mentha of Pancalieri" essential oil (MPP) on intracellular killing of Candida krusei, often resistant to conventional drugs, by polymorphonuclear leucocytes (PMNs). Intracellular killing was investigated by incubating yeasts and PMNs with essential oils (EOs) at 1/4 and 1/8 × MIC (Minimal Inhibitory Concentration), in comparison with anidulafungin, used as a reference drug. Killing values were expressed as Survival Index (SI) values. The cytotoxicity of EOs was evaluated by 3-[4,-5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Both EOs were more efficaceous at 1/8 × MIC than 1/4 × MIC, with killing values higher than observed in EO-free systems and in presence of anidulafungin, indicating that the decreasing concentrations did not cause lower candidacidal activity. This better activity at 1/8 × MIC is probably due to the EOs' toxicity at 1/4 × MIC, suggesting that at higher concentrations EOs might interfere with PMNs functionality. TTO and MPP at 1/8 × MIC significantly increased intracellular killing by PMNs through their direct action on the yeasts (both EOs) or on phagocytic cells (MPP), suggesting a positive interaction between EOs and PMNs to eradicate intracellular C. krusei. These data showed a promising potential application of TTO and "Mentha of Pancalieri" EO as natural adjuvants in C. krusei infection management.

Evaluation of the Antifungal Activity of Mentha x piperita (Lamiaceae) of Pancalieri (Turin, Italy) Essential Oil and Its Synergistic Interaction with Azoles.

The promising antimicrobial activity of essential oils (EOs) has led researchers to use them in combination with antimicrobial drugs in order to reduce drug toxicity, side effects, and resistance to single agents. Mentha x piperita, known worldwide as "Mentha of Pancalieri", is produced locally at Pancalieri (Turin, Italy). The EO from this Mentha species is considered as one of the best mint EOs in the world. In our research, we assessed the antifungal activity of "Mentha of Pancalieri" EO, either alone or in combination with azole drugs (fluconazole, itraconazole, ketoconazole) against a wide panel of yeast and dermatophyte clinical isolates. The EO was analyzed by GC-MS, and its antifungal properties were evaluated by minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) parameters, in accordance with the CLSI guidelines, with some modifications. The interaction of EO with azoles was evaluated through the chequerboard and isobologram methods. The results suggest that this EO exerts a fungicidal activity against yeasts and a fungistatic activity against dermatophytes. Interaction studies with azoles indicated mainly synergistic profiles between itraconazole and EO vs. Candida spp., Cryptococcus neoformans, and Trichophyton mentagrophytes. Thus, the "Mentha of Pancalieri" EO may act as a potential antifungal agent and could serve as a natural adjuvant for fungal infection treatment.

Use of Pinus sylvestris L. (Pinaceae), Origanum vulgare L. (Lamiaceae), and Thymus vulgaris L. (Lamiaceae) essential oils and their main components to enhance itraconazole activity against azole susceptible/not-susceptible Cryptococcus neoformans strains.

BACKGROUND: Cryptococcal 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. METHODS: EO 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. RESULTS: Six 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. CONCLUSIONS: Our 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.

Advances in Microbiology, Infectious Diseases and Public Health: Fungal Occurrence in the Hair and Skin of Symptomatic Pets in Turin, Italy.

Companion animals, often asymptomatic reservoir of fungi, can be important sources of infection in humans, due to the close contact with their owners. The present study was aimed to assess the occurrence of dermatophytes and other fungi isolated from pet dermatological lesions in Turin, Italy. Dermatological specimens were examined for fungal elements by direct microscopy and cultured to detect dermatophytes, other filamentous fungi and yeasts: 247 pets (118 cats, 111 dogs and 18 dwarf rabbits) were positive for fungal detection in culture. Microsporum canis was the most frequent dermatophyte in cats and dogs, whereas Trichophyton mentagrophytes was the most common in rabbits. Among the other fungi, for all examined pets, dematiaceous fungi were the most isolated, followed by Mucorales, penicilli, yeasts and yeast-like fungi, and aspergilli. No gender predisposition was detected for dermatophyte growth; on the contrary, for the other fungi male cats were more susceptible than female. The highest fungal occurrence was recorded in <1-year-old cats for dermatophytes, and in <5-year-old cats and dogs for the other fungi. Autumn was the period associated with a relevant incidence of fungal infection. Finally, fungi were more frequent in non pure-breed cats and in pure-breed dogs. These data underline the importance to timely inform pet owners about the potential health risk of infection caused not only by dermatophytes but also by non-dermatophyte fungi, routinely considered to be contaminants or harmless colonizers, since their role as source of zoonotic infections is not to be excluded.

Advances in Microbiology, Infectious Diseases and Public Health: Refractory Trichophyton rubrum Infections in Turin, Italy: A Problem Still Present.

Dermatophytosis caused by Trichophyton rubrum is the most common cutaneous fungal infection in industrialized countries and worldwide with high recurrence and lack of treatment response. In addition, patients with cutaneous and concurrent toenail lesions are often misdiagnosed and therefore treated with an inappropriate therapy. In this study, we evaluated five previously misdiagnosed cases of T.rubrum chronic dermatophytosis sustained by two variants at sites distant from the primary lesion. Our patients were successfully treated by systemic and topical therapy, and 1 year after the end of therapy follow-up did not show any recurrence of infection.Our data indicate that the localization of all lesions, the isolation and the identification of the causative fungus are essential to establish the diagnosis and the setting of a correct therapeutic treatment to avoid recurrences.

Liquid and vapour-phase antifungal activities of essential oils against Candida albicans and non-albicans Candida.

BACKGROUND: The management of Candida infections faces many problems, such as a limited number of antifungal drugs, toxicity, resistance of Candida to commonly antifungal drugs, relapse of Candida infections, and the high cost of antifungal drugs. Though azole antifungal agents and derivatives continue to dominate as drugs of choice against Candida infections, there are many available data referring to the anticandidal activity of essential oils. Since we have previous observed a good antimicrobial activity of some essential oils against filamentous fungi, the aim of this study was to extend the research to evaluate the activity of the same oils on Candida albicans, C.glabrata and C.tropicalis clinical strains, as well as the effects of related components. Essential oils selection was based both on ethnomedicinal use and on proved antibacterial and/or antifungal activity of some of these oils. Fluconazole and voriconazole were used as reference drugs. METHODS: The minimum inhibitory concentration (MIC) and the minimal fungicidal concentration (MFC) of essential oils (thyme red, fennel, clove, pine, sage, lemon balm, and lavender) and their major components were investigated by the broth microdilution method (BM) and the vapour contact assay (VC). RESULTS: Using BM, pine oil showed the best activity against all strains tested, though C.albicans was more susceptible than C.glabrata and C.tropicalis (MIC50-MIC90 = 0.06 %, v/v). On the contrary, sage oil displayed a weak activity (MIC50-MIC90 = 1 %, v/v). Thyme red oil (MIC50-MIC90 ≤ 0.0038 %, v/v for C.albicans and C.tropicalis, and 0.0078- < 0.015 %, v/v for C.glabrata), followed by lemon balm, lavender and sage were the most effective by VC. Carvacrol and thymol showed the highest activity, whereas linalyl acetate showed the lowest activity both by two methods. α-pinene displayed a better activity by BM than VC. CONCLUSION: Results show a good activity of essential oils, mainly thymus red and pine oils, and their components carvacrol, thymol and α-pinene against Candida spp., including fluconazole/voriconazole resistant strains. These data encourage adequately controlled and randomized clinical investigations. The use in vapour phase could have additional advantages without requiring direct contact, resulting in easy of environmental application such as in hospital, and/or in school.

Key Roles of Human Polymorphonuclear Cells and Ciprofloxacin in Lactobacillus Species Infection Control.

Lactobacilli have the potential to act as reservoirs of antibiotic resistance genes similar to those found in human pathogens, with the risk of transferring these genes to many pathogenic bacteria. In this study, we investigated the role of human polymorphonuclear cells (PMNs) against Lactobacillus spp. both resistant and susceptible to ciprofloxacin (a fluoroquinolone) and the effect of ciprofloxacin on the interaction between PMNs and three Lactobacillus spp. with different patterns of susceptibility to this drug. Hence, the primary functions of PMNs, such as phagocytosis and bacterial intracellular killing, against lactobacilli were investigated. The rate of PMN phagocytosis was high for ciprofloxacin-sensitive and ciprofloxacin-resistant strains. The patterns of intracellular killing of ciprofloxacin-sensitive and ciprofloxacin-resistant strains by PMNs underline that PMNs alone were able to kill lactobacilli. The addition of ciprofloxacin to PMNs did not result in a significant increase in the bacterial uptake by phagocytes. On the contrary, ciprofloxacin had a marked effect on PMN intracellular killing, resulting in increased numbers of killed ciprofloxacin-sensitive bacteria in comparison with antibiotic-free controls. Our data show that by itself, the profile of antibiotic resistance does not constitute an intrinsic factor of greater or lesser pathogenicity toward the host. The ability of PMNs to kill a diverse array of bacterial pathogens is essential for human innate host defense, primarily in immunocompromised patients.

In vitro antifungal activity of fluconazole and voriconazole against non-Candida yeasts and yeast-like fungi clinical isolates.

The risk of opportunistic infections caused by non-Candida yeasts and yeast-like fungi is increasingly common, mainly in immunocompromised patients. Appropriate first-line therapy has not been defined and standardized, mainly due to the low number of cases reported. To improve empirical treatment guidelines, we describe the susceptibility profile to fluconazole and voriconazole of 176 non-Candida yeasts and yeast-like fungi collected from hospitals in Piedmont, North West Italy from January 2009 to December 2013. The results showed that most isolates are susceptible to voriconazole (94%), but less susceptible to fluconazole (78%), suggesting that voriconazole could be used as first-line therapy in infections caused by these fungi.