effect of temperature on production of ochratoxin a by aspergillus niger in orange juice

This challenging study was carried out to evaluate the temporal production of ochratoxin A (OTA) byAspergillus nigerATCC 16404 and wild typeA. nigerAM at different temperatures in fresh squeezed orange juice (Citrus sinensis[L.] Osbeck cv Tarocco). Each strain, inoculated into the filtered orange juice, was incubated at 4°C, 20°C, and 26°C for 28 days. In the juice, at 26°C and 20°C, the concentration ofA. nigerATCC 16404 increased by more than 2 log10up to the 21st day. At 4°C it remained constant. The microbial load ofA. nigerAM decreased at all temperatures. At 26°C, the maximum OTA accumulation found was 3.44 ng/mL on the 21st day forA. nigerATCC 16404 and 8. 44 ng/mL on the 7th day forA. nigerAM. The OTA synthesis seemed to be an intrinsic strain-dependent mechanism.A. nigerATCC 16404 produced OTA in accordance with the higher temperatures and the biomass concentrations, whereasA. nigerAM produced the toxin at all temperatures regardless of its biomass. These results showed that fresh orange juice contaminated withAspergillus nigeraggregate strains may contain OTA levels

SO045A NATIONWIDE SURVEY ON RADIATION RISK OF CANCER FROM MEDICAL IMAGING IN END STAGE KIDNEY DISEASE AND IN TRANSPLANT PATIENTS

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Efficacy of a Fixed Combination of Tetracycline, Chloramphenicol, and Colistimethate Sodium for Treatment of Candida albicans Keratitis

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Resveratrol role in<i>Staphylococcus aureus</i>-induced corneal inflammation

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Antimicrobial additives for poly(lactic acid) materials and their applications: current state and perspectives

Poly(lactic acid)-based antimicrobial materials received considerable attention as promising systems to control microbial growth. The remarkable physicochemical properties of PLA such as renewability, biodegradability, and US Food and Drug Administration (FDA) approval for clinical use open up interesting perspectives for application in food packaging and biomedical materials. Nowadays, there is an increasing consumer demands for fresh, high-quality, and natural foods packaged with environmentally friendly materials that prolong the shelf life. The incorporation of antimicrobial agents into PLA-based polymers is likely to lead to the next generation of packaging materials. The development of antimicrobial PLA materials as a delivery system or coating for biomedical devices is also advantageous in order to reduce possible dose-dependent side effects and limit the phenomena of antibiotic resistance. This mini-review summarizes the most recent advances made in antimicrobial PLA-based polymers including their preparation, biocidal action, and applications. It also highlights the potential of PLA systems as efficient stabilizers-carriers of various kinds of antimicrobial additives including essential oils and other natural compounds, active particles and nanoparticles, and conventional and synthetic molecules

Activity of Colloidal Silver Solution against Microorganisms Implicated in Ocular Infections

Endophthalmitis most likely originates from both planktonic bacteria suspended in the tear film and bacteria adherent to the conjunctiva and the eyelid. This study aimed to expand the research on the effectiveness of a colloidal silver solution (Silverix&reg;) against ocular microorganisms. The activity of Silverix&reg; was evaluated against methicillin-resistant Staphylococcus aureus, S. epidermidis, ofloxacin-resistant Pseudomonas aeruginosa, and Candida albicans strains, previously characterized for their antibiotic resistance and biofilm-forming capabilities. The microbial killing was estimated at various times in the presence and absence of colloidal silver solution against planktonic and biofilm-embedded cells. The results documented the efficacy of Silverix&reg; on planktonic cells of S. aureus and S. epidermidis (2.49&ndash;2.87 Log CFU/mL reduction) and P. aeruginosa strains (3&ndash;4.35 Log CFU/mL reduction). On the contrary, C. albicans showed mild susceptibility. Regarding early biofilm, the ocular isolates were harder to kill (2&ndash;2.6 Log CFU/mL reduction) than the reference strains, whereas a similar decrease (3.1 Log CFU/mL reduction) was estimated for P. aeruginosa strains. The light microscope images of biofilms treated with colloidal solution confirmed the ability of Silverix&reg; to destroy the biofilm

Activity of Colloidal Silver Solution against Microorganisms Implicated in Ocular Infections

Endophthalmitis most likely originates from both planktonic bacteria suspended in the tear film and bacteria adherent to the conjunctiva and the eyelid. This study aimed to expand the research on the effectiveness of a colloidal silver solution (Silverix®) against ocular microorganisms. The activity of Silverix® was evaluated against methicillin-resistant Staphylococcus aureus, S. epidermidis, ofloxacin-resistant Pseudomonas aeruginosa, and Candida albicans strains, previously characterized for their antibiotic resistance and biofilm-forming capabilities. The microbial killing was estimated at various times in the presence and absence of colloidal silver solution against planktonic and biofilm-embedded cells. The results documented the efficacy of Silverix® on planktonic cells of S. aureus and S. epidermidis (2.49–2.87 Log CFU/mL reduction) and P. aeruginosa strains (3–4.35 Log CFU/mL reduction). On the contrary, C. albicans showed mild susceptibility. Regarding early biofilm, the ocular isolates were harder to kill (2–2.6 Log CFU/mL reduction) than the reference strains, whereas a similar decrease (3.1 Log CFU/mL reduction) was estimated for P. aeruginosa strains. The light microscope images of biofilms treated with colloidal solution confirmed the ability of Silverix® to destroy the biofilm

Phytochemical characterization, and antioxidant and antimicrobial properties of agitated cultures of three rue species : <I>Ruta chalepensis, Ruta corsica,</I> and <I>Ruta graveolens</I>

The in vitro cultures of the following three species of the genus Ruta were investigated: R. chalepensis, R. corsica, and R. graveolens. The dynamics of biomass growth and accumulation of secondary metabolites in the 3-, 4-, 5-, 6-, and 7-week growth cycle were analysed. The antioxidant capacity of the methanol extracts obtained from the biomass of the in vitro cultures was also assessed by different in vitro assays: 1,1-diphenyl-2-picrylhydrazil (DPPH), reducing power, and Fe(2+) chelating activity assays. Moreover, a preliminary screening of the antimicrobial potential of the extracts was performed. The extracts were phytochemically characterized by high-performance liquid chromatography (HPLC), which highlighted the presence of linear furanocoumarins (bergapten, isoimperatorin, isopimpinellin, psoralen, and xanthotoxin) and furoquinoline alkaloids (γ-fagarine, 7-isopentenyloxy-γ-fagarine, and skimmianine). The dominant group of compounds in all the cultures was coumarins (maximum content 1031.5 mg/100 g DW (dry weight), R. chalepensis, 5-week growth cycle). The results of the antioxidant tests showed that the extracts of the three species had varied antioxidant capacity: in particular, the R. chalepensis extract exhibited the best radical scavenging activity (IC(50) = 1.665 ± 0.009 mg/mL), while the R. graveolens extract displayed the highest chelating property (IC(50) = 0.671 ± 0.013 mg/mL). Finally, all the extracts showed good activity against Staphylococcus aureus with MIC values of 250 μg/mL for the R. corsica extract and 500 μg/mL for both R. graveolens and R. chalepensis extracts

Antioxidant potential and enhancement of bioactive metabolite production in in vitro cultures of <I>Scutellaria lateriflora</I> L. by biotechnological methods

Studies carried out using three different in vitro assays and a biological setting (Escherichia coil) demonstrated the antioxidant activity of Scutellaria lateriflora microshoot extract. Moreover, the extract exhibited no toxicity in a brine shrimp lethality bioassay. These results indicated that microshoots are a rich, safe source of antioxidants, which encouraged us to enhance their production in vitro. In agar and agitated cultures, two biotechnological strategies were applied: feeding the cultures with the biogenetic precursors of the phenolics&mdash;phenylalanine and tyrosine, and eliciting them with methyl jasmonate. Specific Scutellaria flavonoids and verbascoside were analysed by HPLC. Feeding with precursors (1 g/L) in agar cultures decreased the production of the metabolites. In agitated cultures, different concentrations of precursors (1.0&ndash;2.5 g/L) and the elicitor (10; 50; 100 &micro;M) were tested. Additionally, parallel feeding with the precursor and elicitor in a concentration of 50 &micro;M were applied. The best strategy for total flavonoid and verbascoside production was phenylalanine feeding (1.5 g/L), max. 3765 and 475 mg/100 g DW, respectively, after 7 days. This is the first report documenting the high antioxidant production in S. lateriflora microshoots after feeding with phenylalanine. Moreover, for the first time, bioreactor cultures were successfully maintained, obtaining attractive results (max. total flavonoid content 2348 and verbascoside 485 mg/100 g DW)

Efficacy of poly(lactic acid)/carvacrol electrospun membranes against Staphylococcus aureus and Candida albicans in single and mixed cultures

Carvacrol (CAR) is one of the most promising essential oil components with antimicrobial activity. New technologies aimed to incorporate this active molecule into carrier matrix to improve the stability and prolong the biological activity. The goal of this study was to investigate the feasibility of incorporating CAR into electrospun membranes of poly(lactic acid) (PLA) for potential applications as active antimicrobial system. To this end, PLA membranes containing homogeneously dispersed CAR were successfully prepared and a series of systematic tests including morpho-mechanical properties, in vitro release rate, and antimicrobial/antibiofilm activities against Staphylococcus aureus and Candida albicans were carried out. The results revealed that CAR has a good compatibility with PLA and acts as a plasticizer, improving flexibility and extensibility of the matrix. The gradual release of CAR from PLA membranes warranted a significant antimicrobial activity up to 144&nbsp;h and reduced the biofilm production by 92\u201396 and 88\u201395% of S. aureus and C. albicans in single and mixed cultures. A strong decrease of cell count, biomass, metabolic activity, and vitality of established 24- and 48-h biofilms were also demonstrated. In conclusion, this work highlights the potential of electrospun nanofibrous membranes as efficient stabilizers-carriers of CAR and opens up interesting perspectives on the use of this system as new tool for skin and wound bacterial\u2013fungal infections