• Journal of fish pathology
• /
• v.21 no.1
• /
• pp.29-34
• /
• 2008

In this study, we examined in vitro antimicrobial activity of the hydrolysis compound (MBT-01108) of cactus stem (Opuntia ficus-indica var. saboten Makino) against 18 strains of fish pathogenic bacteria, Edwardsiella tarda, Listonella anguillarum, Vibrio sp., Lactococcus garvieae, L. raffinose, Streptococcus parauberis and S. iniae. Antibiotic susceptibility of the same bacteria was also assayed to commercial discs containing various antibacterials. According to these results, MBT-01108 showed the excellent antimicrobial activity against the tested pathogenic bacteria.

• Journal of Life Science
• /
• v.17 no.9 s.89
• /
• pp.1278-1283
• /
• 2007

The 30% resistant frequencies of pathogenic bacteria were identified against generally utilizing disinfectants. Among the used disinfectants, foodsef, Taego, and Iodo 175 were dictated by lower sensitivities against pathogenic bacteria, as well as higher resistant frequencies when compared with other disinfectants. The resistant frequencies against antibiotics were also dictated by 30% through MIC (minimal inhibitory concentration) and paper disc methods. Especially, the used bacteria exhibited resistances against gentamycin, kanamycin, and streptomycin, which included in all aminoglycoside group. The MBT-01108 material, which extracted and purified from a powder obtained by processing of Opunita ficus-indica var. saboten Makino trunk, did not develop or grow resistant bacteria. Interestingly, the multi-drug resistant bacteria such as MRSA, resistant Pseudomonas aeruginosa, VRE, and E. coli 0157 did not resistant against MBT-01108 material. These results suggest that MBT-01108 material uses as an anti-microbial agent.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.42 no.1
• /
• pp.34-40
• /
• 2009

In fresh water fish hatcheries and farms, Saprolegniales often cause serious mortality to the fish and their eggs. Malachite green is an effective antifungal agent, but is carcinogenic to fish and humans. Alternative antifungal agents are needed. Presently, we tested various concentrations of MBT-01108 (Opuntia ficus-indica extracts) alone and in combination with bronopol, formalin and sodium chloride (MBT-01108 mixture) on in vitro mycelial growth and in vivo remediation of adult eel, Anguilla japonica, infected with Saprolegnia sp. and fertilized eggs of chum salmon, Oncorhynchus keta, to evaluate the compounds' antifungal efficacy on eyed-egg and hatching rates. MBT-Oll08 mixtures incorporating bronopol and formalin at respective concentrations of 50 and 30 parts per million (ppm), and 100 and 20 ppm were most effective in controlling Saprolegnia in vitro and in vivo (P<0.05). Repeated daily exposures to 50 ppm and 100 ppm MBT-01108 were more effective than exposure every 2-3 days post-fertilization for the inhibition of Saprolegnia infection of rainbow trout, Oncorhynchus mykiss eggs as compared with control (0 ppm).

• Journal of fish pathology
• /
• v.20 no.2
• /
• pp.179-187
• /
• 2007

Hydrolysis compound of cactus of opuntia genus, Opuntia ficus-indica var. saboten Makino, has predominant anti-bacterial, anti-fungal effects. In this study, we wont to know a preventive effects of bacterial disease on cultured flounder using the compound (MBT-01108), and physical and physiological responses of those fishes were examined additionally. The MBT-01108 shown any side effect on physical, hematological and histological conditions of fishes. Immunologically, CL (chemiluminescense) response were appeared at MBT-01108 (0.1%) feeding group for 4 weeks. The results of comparative livability at a experimental infection with E.tarda and S.iniae were 82.5% and 13.5% at 4 weeks MBT (0.1%) feeding group.

• Journal of Life Science
• /
• v.17 no.7 s.87
• /
• pp.915-922
• /
• 2007

In order to discover physiologically active substance, we investigated a powder obtained by processing of Opuntia ficus-indica var. saboten Makino trunk. The powder was treated by sulfuric acid and then extracted by several solvents such as methanol, methylene chloride, ethanol etc. Among them, the best antimicrobial activity was showed by methylene chloride extract. To identify materials exhibiting physiological activation, the acid hydrolyzed extract was separated by 7 fractions through preparative silica gel TLC. The effective fraction exhibiting the best broad antimicrobial activity was identified, named as MBT-01108. From structural analysis of the products extracted to acid hydrolysis, a compound exhibiting the antimicrobial activities is identified to levulinic acid. Levulinic acid isolated from Opuntia ficus-indica var. saboten Makino may be applicable as a natural preservative of food or cosmetic and for prevention of bacterial diseases, an ingredient of acne, ageing and whitening cosmetics and an antimicrobial agent.

• Journal of fish pathology
• /
• v.20 no.2
• /
• pp.147-160
• /
• 2007

Four strains of water mold, ChS-E0511, RaT-E0511, RaT-A0512 and MaS-F0512, were isolated from salmonid fish and/or their eggs taken from culture farms in Yangyang, Milyang and Pyeongchang, Korea in 2005. Descriptions of their morphological aspects, the results of the phylogenetic analysis conducted, and the sequence of the small sub-unit 18S rRNAs of the isolates confirmed that they all belong to the species Saprolegnia parasitica. Only one species, ChS-E0511, which was isolated from fertilized eggs of the chum salmon, was classified as part of the S. parasiticaGroup 1 according to its oogonia and gemmae production. The chemotherapeutic effects of various chemicals on the ChS-E0511 strain were assessed from the inhibitory effects of growth in GY media and the relative ratio of eyed eggs to fertilized eggs of the rainbow trout. Malchite green, a prohibited substance in food animals, was better than others, such as the Opuntia ficus-indicaextract, 2-bronopol, and sodium chloride. These results suggest that the fungi isolated from salmonids and/or their eggs identified as S. parasitica were composed of more than two groups. These isolates will be useful in an intensive evaluation of therapeutic agents.