A novel nano-sulphur and essential oil-based room freshener

Introducción: Alternaria spp y Candida spp. son hongos patógenos de ambientes interiores como la casa, la oficina, el aula, etc., causan enfermedades como asma crónica e infecciones sistémicas en individuos inmunodeprimidos a través de la secreción de diversas sustancias tóxicas. Los ambientadores a base de productos químicos disponibles comercialmente que se utilizan para controlar la carga de hongos en el ambiente interior no son beneficiosos para la salud humana. Objetivo: proporcionar una alternativa viable en forma de enfoque basado en nanopartículas para el manejo de hongos transmitidos por el aire. Metodología: aislamiento, identificación microscópica y bioquímica de hongos de interior; Síntesis de nanopartículas de azufre (SNP) mediadas por Azadirachta indica, su detección y caracterización; y evaluación in vitro de SNP contra hongos aislados presentes en el ambiente interior. Resultado: Los hongos aislados se identificaron como especies de Alternaria spp y Candida spp. Los SNP mostraron máximos de absorbancia a 291 nm. El análisis NTA mostró un tamaño medio de 188,4 nm y un potencial zeta de -4,94 mV, lo que representa una síntesis de SNP estables. El patrón XRD confirmó la naturaleza cristalina cúbica centrada en la cara de los SNP. El espectro FTIR representó la presencia de compuestos polihidroxilo, nitrilo, ceto, aromáticos y carboxílicos que estabilizaron los SNP. Los ensayos antifúngicos demostraron la actividad significativa de los SNP formulados y del ambientador infundido con aceite de eucalipto. Conclusión: Los SNP mediados por A. indica se pueden aplicar en la formulación y fabricación de un ambientador ecológico para el manejo de hongos patógenos de interior como Alternaria spp y Candida spp.

Introduction: Alternaria spp. and Candida spp. are the main fungal pathogen of indoor environment like house, office, classroom, etc. These may cause various diseases and infections like systemic infections, or chronic asthma in immunocompromised individuals through secretion of various toxic substances. Chemical-based commercially available room fresheners used to control the fungal load of indoor environment are not beneficial to human health. Objective: was to provide viable alternative in the form of nanoparticle-based approach for the management of air-borne fungi. Methodology: The present study primarily focuses on the isolation, microscopic and biochemical identification of indoor fungi; Azadirachta indica-mediated sulphur nanoparticles (SNPs) synthesis, their detection and characterization; and in vitro assessment of SNPs against isolated fungi present in indoor environment. Result: The isolated fungi were identified as Alternaria spp and Candida spp. The SNPs showed absorbance maxima at 291 nm. NTA analysis showed average size of 188.4 nm, and zeta potential of -4.94 mV which represented synthesis of stable SNPs. XRD pattern confirmed the face centered cubic, crystalline nature of SNPs. FTIR spectrum depicted the presence of polyhydroxyl, nitrile, keto, aromatic and carboxylic compounds which stabilized the SNPs. The antifungal assays demonstrated the significant activity of the formulated SNPs and eucalyptus oil infused air freshener. Conclusion: It can be concluded that A. indica-mediated SNPs can be applied in the formulation and manufacture of an ecofriendly air freshener for the management of indoor fungal pathogens like Alternaria spp. and Candida spp.

Infectious Crystalline Keratopathy Caused by Alternaria

PURPOSE: To report a case of infectious crystalline keratopathy caused by Alternaria in the corneal center. CASE SUMMARY: A 66-year-old male visited our clinic with right ocular pain and visual loss after corneal trauma caused by a foreign body hitting his right eye while performing farm work 1 month prior to his visit. The patient had no history of corneal surgery and long-term use of topical corticosteroid. A corneal epithelial defect and whitish snowflake margin infiltration around the corneal stroma were observed in the corneal center, but there was an absence of conjunctival injection and anterior segment inflammation. Cultures and a biopsy of the corneal scrapings revealed Alternaria species fungus. The patient was treated with 1% topical voriconazole and 0.5% moxifloxacin, together with oral voriconazole (400 mg/day). After 2 months of treatment, the disease was completely cured, with a minute corneal opacity. CONCLUSIONS: We successfully treated a rare case of infectious crystalline keratopathy caused by Alternaria, which has not been previously reported in the Republic of Korea.

Antibacterial mechanisms of endophytic fungi Alternaria alternata of ethyl acetate extract on Escherichia coli / 中草药

Objective To study the antibacterial mechanisms of ethyl acetate extract (B06e) from the fermentation liquid of an endophytic fungus Alternaria spp. Alternaria spp isolated from the medicinal plant Humata tyermanni. Methods Double dilution method was adopted to measure the minimum inhibitory concentration (MIC) of B06e against Escherchia coli. Then, the changes of electric conductivity of bacterial culture, nucleic acid and protein concentration before and after treated by B06e were analysed, respectively. Besides, flow cytometry, scanning electron microscopy, gel retardation experiments, circular dichroism spectrum and Real-time quantitative PCR were introduced to study the antimicrobial mechanisms of B06e against E. coli. Results The results showed that MIC value of B06e against E. coli was 25 μg/mL. The electric conductivity of 3 × MIC treatment group was 1.01 times the value of the control group. The β-galactosidase activity of 3 × MIC treatment group was 11.6 times more than the value of the control group. Flow cytometry analysis showed that PI positive cells ratio of 3 × MIC treatment group was 286.5 times the value of the control group. Scanning electron microscopy showed that cell surface becomes rough after the treatment of B06e, a large number of cell membrane collapse. These results suggested that B06e can increase the permeability of cell membrane, destroy the integrity of cell membrane. The results of gel retardation experiments and circular dichroism spectrum applied that B06e can be inserted into DNA structure at particular position, however, can not cause DNA degradation. Real-time quantitative PCR results showed that the expressions of recA and recN genes were both up-regulated with the values of 2.9 and 3.7 times the value of the control group, respectively. This result suggested that B06e can destroy the DNA structure, which force E. coli to initiate SOS repair. Conclusion B06e can kill E. coli cell by destroying the cell membrane and damaging DNA structure.

Plant extracts and essential oils on the control of Alternaria alternata, Alternaria dauci and on the germination and emergence of carrot seeds (Daucus carota L.) / Extratos e óleos essenciais vegetais no controle de Alternaria alternata, Alternaria dauci e na germinação e emergência de sementes de cenoura (Daucus carota L.)

ABSTRACT: The present study aims to investigate garlic, pepper and coriander plant extract as well as neem and orange peel essential oil effective ness to control Alternaria alternata and Alternaria dauci and their efficiency during carrot seeds germination and emergence. A completely randomized design was used in three different experiments. The first experiment evaluated the effect of plant extracts and essential oils on the incidence of A. alternata and A. dauci. It was done by means of a factorial design applied to five treatments (garlic, pepper, coriander, and neem and orange peel essential oils) at three concentrations (10, 20 and 30%).They also evaluated the controls untreated and with fungicide (Thiram).The second experiment evaluated the effect of the treatment at30% concentration on the germination and emergence of seedlings assessed on trays, and in the third experiment, the presence of A. alternata and A. dauci on the pericarp, endosperm and on the embryo. A. alternata showed higher incidence than A. dauci. The garlic extract and the orange essential oil showed the potential to control A. dauci and A. alternata, because their lower concentrations were able to sufficiently reduce the incidence of these fungi and because they do not affect carrot seeds germination and emergence. A. alternata conidia were found on the embryo (8%), pericarp (17%) and endosperm (31%).

RESUMO: O presente estudo teve por objetivo verificar a eficiência de extratos vegetais de alho (Allium sativum L.), pimenta dedo-de-moça (Capsicum baccatum L.), coentro (Coriandrum sativum L.), óleos essenciais de nim (Azadirachta indica A. Juss.) e laranja (Citrus sinensis L. (Osbeck)) no controle de A. alternata e A. dauci, bem como, sobre a germinação e emergência de sementes de cenoura. Foram realizados três experimentos com delineamento experimental inteiramente casualizado. No primeiro experimento, avaliou-se o efeito dos extratos e óleos essenciais vegetais sobre a incidência de A. alternata e A. dauci, em esquema fatorial com cinco tratamentos (alho, pimenta, coentro e óleos essenciais de nim e de laranja), em três concentrações (10, 20 e 30%), acrescido das testemunhas sem tratamento e com fungicida (Thiram). No segundo experimento, avaliou-se o efeito dos tratamentos a 30%, sobre a germinação e emergência de plântulas em bandejas e, no terceiro, a presença de A. alternata e A. dauci no pericarpo, endosperma e embrião. O fungo A. alternata apresentou maior incidência que A. dauci. O extrato de alho e o óleo essencial de laranja demonstraram potencial para o controle de A. alternata e A. dauci, pois, na menor concentração, reduziram satisfatoriamente a incidência desses fungos e foram inócuos a germinação e emergência de sementes de cenoura. Conídios de A. alternata foram identificados no embrião (8%), pericarpo (17%) e endosperma (31%).