Fungal infection mostly caused by marine oomycetes had hindered crustacean production thus searching for natural and safe treatment is currently needed. Thus, this study was conducted to investigate the antimycotic effect of different seaweed extract against marine oomycetes (Lagenidium spp. and Haliphthorosspp) . Two seaweeds species (Eucheuma cottonii and Caulerpa lentillifera) were extracted using ethanol, methanol and water. Each extracts was tested on four fungi strains of marine oomycetes species for minimum inhibitory concentration (MIC) and fungicidal activities. C. lentillifera ethanol extract showed the highest antifungal effect where it can inhibit three from four fungal strains. Meanwhile, E. cottonii ethanol extract has lowest MIC (500 ppm) and inhibit L. thermophilum IPMB 1401 and H. sabahensis IPMB 1402 hyphal growths. Antimycotic effect on zoospores production shows reduction in production after 12 h immersion for three marine oomycetes species. Seaweed extracts toxicity on Artemia sp. showed approximately 5% mortality at 12 h immersion. It is suggested that 12 h immersion of seaweed extract is a suitable treatment for marine oomycetes in aquaculture. This study does not only show potential alternative control method for crab larvae health management, it may also contribute to the sustainable development and food security of aquaculture industry.
Role of Trichoderma species is well documented as antagonists as well as plant growth enhancers. Presently, the fungicidal potential of three Trichoderma species namely, T. koningii (FCBP769) , T. viride (FCBP904) , and T. harzianum (FCBP1277) was assessed against Alternaria alternata that causes leaf necrotic spots of Syzygium cumini and broad range of other plants using 0, 15, 30, 45, 60 and 75% dilutions of filtrates. There was a significant reduction of around 40-95%, 22-86% and 52-91% in fungal biomass by T. koningii, T. viride and T. harzianum, respectively. In fractionation bioassays, Trichoderma metabolites were partitioned using organic solvents viz., n-butanol, n-hexane, chloroform and ethyl acetate. Antifungal activity at different concentrations (10, 20, 30, 40 and 50 ppm) was assessed against the pathogen. Ethyl acetate fraction of T. koningii extract displayed the most promising activity resulting in 10-90% suppression in biomass. In case of T. viride butanol fraction proved the most effective in retarding the growth of pathogen from 20 to 80%. While T. harzianum extract revealed 55-85% arrest in fungal biomass due to n-hexane fraction. Present study concludes that test Trichoderma species demonstrated a strong fungicidal activity against A. alternata. Current research offers the possibility of developing strategies for controlling pathogens with bioactive metabolites of Trichoderma.
In 2017, 2 household washing machines which were used at a house in Saitama prefecture were tested for fungal flora sampling. The fungi were identified in detail via genetic analysis of the ITS region. The number of fungi which were isolated were 8.7×106～6.1×107 cfu/100cm2 and dematiaceous fungi such as Ochroconis musae, Exophiala, Cyphellophora, Knufia epidermidis were dominant. As for Knufia epidermidis, this is the first report for identification from a Japanese household. The number of isolated Cladosporium, which is common in the environment, was fewer compared with the above 4 genera. The identified fungi were Cladosporium halatolerans, which is recently being recognized as the main species of Cladosporium. In our research, we have cleaned the 2 washing machines with different bleaches. Residual fungi was detected in washing machine A, which was cleaned with an oxygen bleach. On the other hand, no fungi was detected in washing machine B, which was cleaned with a chlorine bleach.
Hydrogen peroxide is widely used as a disinfectant by generating oxidative stress. The chelate of ethylenediaminetetraacetic acid (EDTA) and ferrous iron (EDTA-Fe) was used to increase oxidative stress and bactericidal effects. The Escherichia coli (E. coli) was added to a beef extract culture medium and treated with various doses of test reagents, including hydrogen peroxide, EDTA-Fe chelate, and antioxidants (vitamin C and vitamin E) . All reagents were scanned individually or in combination to trace potential interference in optical density (OD) measurements and eliminate reagent-related interference. Medium supplemented with 13.79 mM hydrogen peroxide resulted in a large increase in the mortality of E. coli, and the highest disinfection efficiency for EDTA-Fe was observed at a neutral pH. The death of the cell of E. coli was significantly inhibited by the presence of catalase, but not vitamins C and E, suggesting that hydroxyl radicals were not generated during the EDTA-Fe-hydrogen peroxide reaction.
The bactericidal activity of heated bio-shell calcium oxide (BiSCaO) powder suspension (pH 12.4) , hypochlorous acid (HClO; pH 6), sodium hypochlorite (NaClO; pH 8) , povidone-iodine (Isodine solution®) , and chlorhexidine gluconate (Hibiscrub®) under organic matter contaminated environments were compared for tests conducted on wood scraps and pig skin pieces that were incubated with normal bacterial flora (total viable counts and coliform bacteria) . The test results showed that BiSCaO suspension had higher bactericidal activity than HClO and NaClO. Furthermore, more than 10-fold higher concentrations of antiseptics such as povidone-iodine and chlorhexidine gluconate were required to achieve bactericidal activity comparable to that of BiSCaO suspension. Our results demonstrate the possibility of using BiSCaO suspension under organic matter contaminated environments as a disinfectant for environmental and food hygiene applications.
Folk herbs are vital to the Japanese health care system, with some being used to treat fungal skin infections. We tested folk herbs used in traditional Japanese medicine for in vitro antifungal activity against Trichophyton rubrum, the most common pathogen in patients with superficial dermatitis. Acetone, ethanol, methanol, water, and acetic acid extracts from 15 species of Japanese folk herbs (Bi-wa, Aka-me-gashiwa, Ta-mushi-ba, Yomogi, Shi-so, Ku-ko, So-ba, Yama-momo, Kuro-mo-ji, Ichi-ji-ku, Kaki-no-ki, Kuwa-no-ki, Kusa-gi, Chimaki-zasa, and I-bukijya-kou-sou) were evaluated for fungal growth inhibition, as measured by absorbance. Crude acetic acid extracts of Aka-me-gashiwa, Ta-mushi-ba, Yomogi, Ku-ko, Kaki-no-ki, and I-bukijya- kou-sou exhibited antifungal activity comparable to that of amphotericin B. Although the active compounds and underlying antifungal mechanisms are not known, the data contribute to the development of new and safe antifungal drugs, highlight new extraction methods for herbs, and support the traditional use of Japanese folk herbs against fungal infections.
This study was to survey the capturing rate in Japanese dental clinics of the Lasioderma serricorne (cigarette beetles) , and to evaluate the beetle’s potential as a carrier for transmission of nosocomial pathogens. L. serricorne imagoes were captured in pheromone traps in 14 Japanese dental clinics in August and September 2012 and 2013, and their numbers recorded. Polymerase chain reaction (PCR) for the bacterial antibiotic-resistant genes mecA, vanA, vanB, blaIMP, and blaVIM was performed on the captured L. serricorne imagoes. Bacterial species in the captured specimens were identified by 16S rRNA PCR and sequencing analysis. The L. serricorne imagoes were captured from 10 dental clinics (71.4%) . We failed to detect the presence of nosocomial antibiotic-resistant pathogens in L. serricorne imagoes. The bacterial species detected most commonly in the imagoes was Wolbachia sp., an intracellular proteobacterium infecting certain insect species. Monitoring of insects including L. serricorne should be incorporated into regiment of the infection control.
Fumigation has been the most convenient method in the field of pest control in museums. In this study, as fumigants, ethanol 70%, deltamethrin (commercial pesticide (CP) ) , essential oil (EO) from Pinus regida, and low oxygen microenvironment (0.1%, (LOM) ) were tested individually and jointly against museum fungal strain Alternaria alternata. Three concentrations of each CP and EO were chosen for evaluating the individual effect. In the joint action fumigation process, three lower concentrations of CP and EO were tested in LOM. The rate of mycelial growth inhibition at each fumigation process was determined by two steps: 1) directly after the fumigation process and 2) after 7 d of the inoculation of the fumigated spores in new medium and incubating it in normal condition. The results demonstrated that applying of each chemical (CP or EO) in LOM enhanced its fungicidal activity and that effect of EO improved from fungistatic to fungicidal by jointing with LOM.