In this study, six in situ gelling formulations based on Gelrite were prepared and evaluated for the retained ophthalmic delivery of Moxifloxacin (Mox). The effectiveness of the best developed formula G5 was compared with photodynamic therapy (PDT), the recent expanding approach for the treatment of ophthalmologic disorders after the assessment of optimum photodynamic inactivation parameters that permit efficient pathogens eradication. It was found that, Staphylococcus aureus (S. aureus) (Gram-positive) was more susceptible to effective lethal photosensitization that reaches 93.5% reduction in viable count than Escherichia coli (E. coli) (Gramnegative) of 76.1% using 3 mg/mL Hematoporphyrin (HP), illuminated by 630 nm Light Emitting Diode (LED) at 9 J/cm(2) and incubated for 15 min. Following topical instillation of G5 to rabbits corneas, higher amount of Mox was retained in the aqueous humor up to 24 h with significant 6-fold increase in the C(max) and AUC((0-∞)) compared to vigamox commercial eye drops. After post corneal infection with S. aureus, both approaches were effectively treating the infection without causing ocular irritation or collateral damage to corneal tissue where G5 showed remarkable improvement after four days compared to seven days of PDT treatment.

In an in vitro study with five clinical isolates of dermatophytes, the MIC 50 and MIC 100 values of silver nanoparticles (AgNPs) ranged from 5 to16 and from 15 to 32 mg ml 21, respectively. The combined treatment of AgNPs with atmospheric pressure-air cold plasma (APACP) induced a drop in the MIC 50 and MIC 100 values of AgNPs reaching 3-11 and 12-23 mg ml 21, respectively, according to the examined species. Epidermophyton floccosum was the most sensitive fungus to AgNPs, while Trichophyton rubrum was the most tolerant. AgNPs induced significant reduction in keratinase activity and an increase in the mycelium permeability that was greater when applied combined with plasma treatment. Scanning electron microscopy showed electroporation of the cell walls and the accumulation of AgNPs on the cell wall and inside the cells, particularly when AgNPs were combined with APACP treatment. An in vivo experiment with dermatophyte-inoculated guinea pigs indicated that the application of AgNPs combined with APACP was more efficacious in healing and suppressing disease symptoms of skin as compared with the application of AgNPs alone. The recovery from the infection reached 91.7 % in the case of Microsporum canis-inoculated guinea pigs treated with 13 mg ml 21 AgNPs combined with APACP treatment delivered for 2 min. The emission spectra indicated that the efficacy of APACP was mainly due to generation of NO radicals and excited nitrogen molecules. These reactive species interact and block the activity of the fungal spores in vitro and in the skin lesions of the guinea pigs. The results achieved are promising compared with fluconazole as reference antifungal drug.

No abstract

F UNGAL infections due to fluconazole-resistant Candida albicans are a serious clinical problem, requiring new efficient antifungal treatment. The present study evaluated the susceptibility of fluconazole-resistant C. albicans to green silver nanoparticles. A total of 40 isolates were examined for the expressions of CDR1, CDR2, and MDR1 gene by quantitative reverse transcription polymerase chain reaction. The antifungal activities of green silver nanoparticles alone and/or in combination with fluconazole (to improve antifungal activity) were assessed by broth microdilution assay and transmission electron microscopy. The effect of fluconazole and/or green silver nanoparticles on the production of C. albicans to protease and phospholipase was also evaluated. And finally, animal model was used to prove the safe and effective use of green silver nanoparticles in the treatment of fluconazole-resistant C. albicans. For all the tested C. albicans strains, the minimum inhibitory concentrations (MICs) of fluconazole and green silver nanoparticles were 64 and 4.84 µg/ml, respectively. Green silver nanoparticles decrease the production of protease and phospholipase enzymes. The expression of both CDR1 and CDR2 were decreased after exposure to green silver nanoparticles, while the expression of CDR 1, CDR 2 and MDR 1 were all decreased when fluconazole and green silver nanoparticles were used. Green silver nanoparticles may be causing suppression of the CDR1, CDR2 and MDR1 expression in fluconazole-resistant C. albicans. The results suggest the use of green silver nanoparticles as a safe and effective treatment against fluconazole-resistant C. albicans.

The objective of this research was to investigate the effect of silver nanoparticles (AgNPs), free or conjugated with monoclonal antibody and mediated by Q-switched Nd:YAG laser on five dermatophytes. The laser was applied for 45 s at 532 nm and 0.8 J/cm2. The application of AgNPs combined with laser caused an increase in fungal susceptibility compared to application of AgNPs alone. The MIC50 and MIC100 recorded 3 and 9 μg/ml in the case of E. floccosum (the most susceptible species), 10 and 19 μg/ml for T. rubrum (the most tolerant species), respectively. A decrease in keratinase activity reaching 76.1, 67.1, and 62.4% was attained in the case of M. gypseum, T. rubrum, and T. mentagrophyte, respectively, on application of 10 μg/ml AgNPs combined with Nd:YAG laser. Under the same conditions of application, a steady increase in leaked materials coupled with reduction in ergosterol synthesis was reached. The structural alterations occurred to the fungus were more observed on the application of AgNPs in combination with laser where the conidia and hyphae lost their cellular integrity, become flaccid, permanently destructed, and completely killed. The monoclonal antibody conjugated AgNPs did not result in significant variation in in vitro experiments compared with that produced by nonconjugated nanoparticles. However, the conjugates achieved significantly more curing of M. canis-inoculated guinea pigs compared with nonconjugated nanoparticles.

No abstract

Bacterial skin infections are a common problem encountered in clinical practice and causing great economic losses for sheep and goats producers. Increasing multidrug resistance of pathogens paves the way for reconsidering alternative medicine. The present study was carried out to explore the antibacterial activities of different volumes; 5, 25, 50 and 100 µL of gold nanoparticles (NPS) and the aqueous and ethanolic extracts of garlic, turmeric and cinnamon at different concentrations (20, 40, 80 and 100%) against molecularly confirmed Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa and Escherichia coli isolated from skin pyogenic lesions in humans, sheep and goats using disc diffusion assay. The results compared with ciprofloxacin (5 µg mL −1). Gold nanoparticles (NPS) 100 µL were highly effective against Pseudomonas aeruginosa and Escherichia coli in comparing with ciprofloxacin (5 µg mL −1 ). Garlic has shown better activity against Staphylococcus aureus and Streptococcus pyogenes in aqueous solution while the ethanolic extract of cinnamon and turmeric was more efficient than the aqueous extract. Among the three tested spices, turmeric was the least effective against tested bacteria. The proven activity of 100 µL Gold nanoparticles (NPS) and 100% aqueous garlic extract compared with ciprofloxacin (5 µg mL −1 ), suggests their use in clinical trials as an alternative medicine to reduce the side effects and progressively increasing drug resistance of pathogens.

A m i r a A . E l -ad l y Im a n I. S hab a na N ahl a A . B o uq el l ah He matoporphy rin -me diated phot osen sitiz ation of aflat oxin -producing Aspergillus s peci es isol ated from meat prod ucts ABSTRACT: Aspergillus spp. grow on foods and feeds generating aflatoxins, which is the most potent carcinogen, therefore the present study aimed to evaluate the deactivation of growth and aflatoxin production of A. flavus and A. parasiticus in the presences of hematoporphyrin dihydrochloride and LED light. One hundred samples of different meat products (hamburger, luncheon, sausage and pastrami) have been used for the study. The isolates were identified classically and molecularly by amplification of ITS regions. The aflatoxin regulatory gene (aflR gene) was amplified and a phylogenetic tree was employed to aflR gene and the AFLR protein sequences. Different concentrations of hematoporphyrin combined with visible light (530 nm) were tested against aflatoxin-producing Aspergillus isolates in vitro and in vivo, using a piece of hamburger. A total of nineteen isolates (15 A. flavus and 4 A. parasiticus) were recovered from the collected samples. Aflatoxin-B1 was detected in 6 isolates (4 A. flavus and 2 A. parasiticus), and aflR gene sequences was assigned in GenBank accession no. KY769955-KY769960. The phylogenetic analysis of aflR genes and the predicted AFLR protein sequences among the strains were greater than 94%. hematoporphyrin photosensitization completely inhibited the growth and aflatoxin production in vitro and in vivo of both A. flavus and A. parasiticus at a concentration of 250 µg/ml. The biochemical analysis of the contaminated hamburger piece showed a decrease in the protein, carbohydrates, and fat content. The results suggest that hematoporphyrin-mediated photosensitization has a potential effect on the inhibition of the growth, spore formation and aflatoxin production of Aspergillus strains in meat products.