• Title/Summary/Keyword: Toxin characteristics

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Detection of $Bacillus$ $cereus$ Group from Raw Rice and Characteristics of Biofilm Formation (쌀로부터 $Bacillus$ $cereus$ Group의 분리와 Biofilm 형성 특성)

  • Kim, Jin-Young;Yoo, Hye-Lim;Lee, Young-Duck;Park, Jong-Hyun
    • The Korean Journal of Food And Nutrition
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    • v.24 no.4
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    • pp.657-663
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    • 2011
  • $Bacillus$ $cereus$ is widely distributed on various foods and is known to cause clinical infections, food poisoning toxin induced diarrhea and vomiting. In this study, $B.$ $cereus$ group detected and analyzed rice, rice bran, and biofilm characterization of $B.$ $cereus$ confirmed. $B.$ $cereus$ was identified in approximately 34.6% of brown rice and 50.0% of rice bran. $B.$ $thuringiensis$ was detected in 3.9% of brown rice and 23% of rice bran, and $B.$ $mycoides$ was isolated from rice bran. The microtiter plate assay detected differences in biofilm-forming ability among $B.$ $cereus$ group isolates. Biofilm of $B.$ $cereus$ seemed to increase the MIC values of antimicrobial agent and antibiotic compounds compared with planktonic cells. Therefore, sufficient attention should be given to good manufacturing practice and good agriculture practice to avoid contamination of $B.$ $cereus$ group raw material including rice.

Studies on Development of Antagonistic Microorganism by Cell Fusion - Biological control of disease - ) (세포융합에 의한 신 길항미생물 육종에 관한 연구 - 목초 병해의 생물학적 방제 -)

  • 최기춘;이영환;전우복
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.15 no.1
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    • pp.1-12
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    • 1995
  • This study was to investigate an effective biological control of forage diseases and provide a basic data and a model in improving variety of antagonistic bacteria, with growth promoting effect on forage, through cell fusion. The results obtained were summarized as follows; 1. The antagonistic himbacterium against soil-borne phathogenic fungi Fusarium oxysporum and Rhizoctonia solani was isolated from continuous cropping himsphere soil of forage, and its biological and physiological characteristics were investigated. This bacterium was identified as Bacillus subrilis and named BS 101. Another strain for cell fusion was Bacillus thur ingiensis ssp. kurstaki HD-I(BT 37669) with insecticidal crystal. 2. The auxotropic mutants of BS 101 and BT 37669 were derived after mutagenesis using N-methyl-N'nitro- Nitrosoguanidine(NTG) to give amino acid requirement marker. n e s e auxotropic mutants of BS 101 and BT 37669 were named BS 1013(his-) and BT 69(asp-), respectively. 3. The best protoplast requirement was obtained using DM 3 medium, containing 5% casamino acid, 1 M $MgCI_2$ and 2% bovine semm albumin, to give Fusant 3, 7 and 8. BT toxin gene was not identified with fusants by Southern blotting. However, SDS-PAGE analysis of strains showed various protein patterns among fusants. 4. From the dark culture experiment, growth of forage in inoculated soil with antagonistic bacteria was delayed than that of non-inoculated soil with antagonistic bacteria in each continuous cropping soil and in each sterilized soil. On the other hand, growth duration of forage was different between continuous cropping soil and sterilized soil. 5. Seed germination of Alfalfa, Italian ryegrass and Orchardgrass were significantly improved by inoculation of antagonistic bacteria(p< 0.05).

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Studies on Pasteurella multocida isolated from pneumonic lungs of slaughter pigs (도축돈의 폐렴병소에서 분리한 Pasteurella multocida 에 대한 연구)

  • Ahn, Byung-chul;Cho, Kwang-hyun;Kim, Bong-hwan
    • Korean Journal of Veterinary Research
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    • v.34 no.3
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    • pp.511-516
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    • 1994
  • P multocida was isolated from 80(17.7%) of 450 pneumonic lungs of slaughter pigs. The majority of the biochemical and cultural characteristics of P multocida isolates were identical to those of the reference strains employed. Seventy seven strains(96.3%) among 80 isolates were capsular serotype A while the remaining 3(3.8%) were serotype D. All isolates were very susceptible to ampicillin, ceftiofur, cephalothin, ciprofloxacin and penicillin-G although some of them were resistant to sulfamethoxin and/or streptomycin. Sixty one(76.3%) of all 80 P multocida isolates were dermonecrotic toxin producers. Out of 77 isolates of serotype A and 3 isolates of serotype D, 59(76.6%) and 2(66.7%) were toxigenic, respectively. No difference was noted in dermonecrotic toxigenicity of the isolates in relation to capsular serotypes.

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Screening and Characterization of Potential Bacillus Starter Cultures for Fermenting Low-Salt Soybean Paste (Doenjang)

  • Jeon, Hye Hee;Jung, Ji Young;Chun, Byung-Hee;Kim, Myoung-Dong;Baek, Seong Yeol;Moon, Ji Young;Yeo, Soo-Hwan;Jeon, Che Ok
    • Journal of Microbiology and Biotechnology
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    • v.26 no.4
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    • pp.666-674
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    • 2016
  • The bacterial strains were screened as potential starters for fermenting low-salt doenjang (a Korean traditional fermented soybean paste) using Korean doenjang based on proteolytic and antipathogenic activities under 6.5-7.5% NaCl conditions. Phylogenetic analysis based on 16S rRNA gene sequences showed that they all belonged to the genus Bacillus. Proteolytic and antipathogenic activities against Escherichia coli, Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, and Aspergillus flavus, as well as fibrinolytic, amylase, and cellulase activities of the 10 strains were quantitatively evaluated. Of these, strains D2-2, JJ-D34, and D12-5 were selected, based on their activities. The functional, phenotypic, and safety-related characteristics of these three strains were additionally investigated and strains D2-2 and D12-5, which lacked antibiotic resistance, were finally selected. Strains D2-2 and D12-5 produced poly-γ-glutamic acid and showed various enzyme activities, including α-glucosidase and β-glucosidase. Growth properties of strains D2-2 and D12-5 included wide temperature and pH ranges, growth in up to 16% NaCl, and weak anaerobic growth, suggesting that they facilitate low-salt doenjang fermentation. Strains D2-2 and D12-5 were not hemolytic, carried no toxin genes, and did not produce biogenic amines. These results suggest that strains D2-2 and D12-5 can serve as appropriate starter cultures for fermenting low-salt doenjang with high quality and safety.

Anterior open bite with temporomandibular disorders treated with intermaxillary traction using skeletal anchorage system

  • Kim, Hye-Sun;Lee, Sang-Hoon;Youn, Taegyun;Kim, Hyung-Gon;Huh, Jong-Ki
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.38 no.5
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    • pp.284-294
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    • 2012
  • Objectives: The anterior open bite with temporomandibular disorders (TMD) is one of the most challenging cases both orthodontically and surgically. We introduce an intermaxillary traction treatment for patients with anterior open bite and TMD using a skeletal anchorage system (SAS). Materials and Methods: This study was comprised of 52 patients with anterior open bite and TMD. A total of four mini-screws were inserted, two screws each into the maxilla and mandible, to obtain a class II pattern of elastic application with 120-200 g force. Adjunctive muscle relaxation treatments, such as splint therapy, medication, and botulinum toxin injection were applied during or before intermaxillary traction. At least one treatment among adjunctive muscle relaxation treatment, mentioned above, was applied to 96.2% of patients. We evaluated the clinical characteristics of patients, TMD symptom changes, amount of open bite improved. The degree of open bite improvement was compared between the open bite-reduced group (21 patients) and not-reduced group (5 patients). Results: TMD symptoms (muscle/joint pain, joint sound, mouth opening) remained or improved in most patients, and worsened in about 10% of patients for each items. Anterior open bite was improved by a mean of 1.75 mm (P<0.01) during treatment. The open bite-reduced group exhibited a significant open bite improvement compared to the not-reduced group (P<0.05), with 37% of open bite improvement occurring during the first 3 months of treatment. Conclusion: The intermaxillary traction technique using SAS is a valid modality for correction of anterior open bite and improvement of TMD symptoms.

Responses of Labeo rohita to Dietary Lathyrus sativus Seeds

  • Barse, A.V.;Jadhao, S.B.;Sahu, N.P.;Srivastava, P.P.;Jain, K.K.;Pal, A.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.1
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    • pp.127-130
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    • 2004
  • Lathyrus sativus, locally known as Khesari, is a leguminous pulse crop grown in many parts of the world for food (used by poor people) and animal feed/fodder. Its seeds are rich in protein and energy but contains anti-nutritional factors prominent among which is ${\beta}$-N-Oxalylamino-L-Alanine (BOAA), a neurotoxin causing lathyrism in humans due to prolong consumption. Keeping in view the chemical characteristics of this toxin and literary facts on L. sativus feeding in terrestrial animals, it was hypothesized that aquatic species may better utilise this ingredient in mixed extruded diets. Diets were prepared with varying levels (0, 10, 18, 26 and 34%) of L. sativus seeds and fed for 60 days to study growth, body composition and digestibility of nutrients. Final body weight, specific growth rate and feed and protein conversion ratio did not differ (p>0.05) between treatments. Crude protein digestibility was reduced (p<0.01) beyond 26% inclusion level of L. sativus. Final carcass composition with regard to protein, lipid and ash did not differ (p>0.05) among the treatments. Comparable craniosomatic, viscerosomatic, renosomatic and hepatic indices and no mortality implies no apparent adverse effect on the vital organs and fish health. It was concluded that L. sativus can be a promising feed ingredient that can be used up to 34% or possibly higher level in fingerlings diet. To our knowledge, it appears to be the first report of its kind under laboratory conditions.

Prospect and Roles of Molecular Ecogenetic Techniques in the Ecophysiological Study of Cyanobacteria (남조류의 생리·생태 연구에서 분자생태유전학적 기법의 역할 및 전망)

  • Ahn, Chi-Yong
    • Korean Journal of Ecology and Environment
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    • v.51 no.1
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    • pp.16-28
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    • 2018
  • Although physiological and ecological characteristics of cyanobacteria have been studied extensively for decades, unknown areas still remain greater than the already known. Recently, the development of omics techniques based on molecular biology has made it possible to view the ecosystem from a new and holistic perspective. The molecular mechanism of toxin production is being widely investigated, by comparative genomics and the transcriptomic studies. Biological interaction between bacteria and cyanobacteria is also explored: how their interactions and genetic biodiversity change depending on seasons and environmental factors, and how these interactions finally affect each component of ecosystem. Bioinformatics techniques have combined with ecoinformatics and omics data, enabling us to understand the underlying complex mechanisms of ecosystems. Particularly omics started to provide a whole picture of biological responses, occurring from all layers of hierarchical processes from DNA to metabolites. The expectation is growing further that algal blooms could be controlled more effectively in the near future. And an important insight for the successful bloom control would come from a novel blueprint drawn by omics studies.

Studies on enterotoxigenic Escherchia coli isolated from piglets with diarrhea (설사 자돈에서 분리된 병원성 대장균에 관한 연구)

  • 김광재;윤교복;최봉출;신은경;김종술;박양주;이유섭
    • Korean Journal of Veterinary Service
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    • v.20 no.4
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    • pp.359-370
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    • 1997
  • This study was carried out to Investigate the biochemical characteristics, antibiotic susceptibility, serogroups and pili producibility test of enterotoxigenic Escherichia coli(ETEC) isolated from piglets with diarrhea in Kangwon province from March to October 1996. 1. Sixty eight E coli strains were isolated from 72 piglets with diarrhea and the biochemical and cultural reaction were compared with the classification criteria of Edwards and Ewing. 2. The serogroups of 26 isolates were classified as 08 : K87 6(8.8%), O20 : K1O1 4(5.9%), O141 : K85 4(5.9%), 09 : K103 : P987 3(4.4%), O45 : K 2(2.9%) 0139 : K82 2(2.9%), O64 : $K^{-}$2(2.9%), O149 : K91 1(1.5%), O157 : K88ac 1(1.5%) and O115 : $K^{-}$1(1.5%), respectively. 3. In antibiotic susceptibility test, the isolates showed high susceptible to Ak, Eno, Na, Gm, Am and Km, whereas resistance to Tc, Sm and Cf. 4. Sixty one strains(89.7%) of 68 I coli Isolates were resistant to one or more drugs. The isolates resistant to 2 and 3 or more drugs were 60.3% and 19.1%, respectively. Amog the 16 multiple resistant patterns, Sm Tc(11.5% ), Cf Sm Tc(11.5% ), Cf Cp Sm Su Tc(9.8% ) and Cf Cp Sm Su Tc(8.2%) patterns were frequently observed. 5. MRHA of guinea pig erythrocytes was detected in 9 out of 26 OK serotype and 9 out of 42 unidentified serotypes. MRHA titers of serotypes showed from 16 to 32 in O141 : K85 and no titers in O139 : K82. 6. By the GM1 ganglioside ELISA, $\beta$-, $\alpha$-, and $\gamma$-hemolysin producing strains was detected as 36, 6, and 5 from heat labile enterotoxin(LT) of 47 ETEC, respectively. The distribution of LT toxin from 112 isolates was showed $\beta$- hemolysin, 2 isolates $\alpha$-hemolysin and 3 isolates $\gamma$-hemol-ysin from 26 OK serotypes.

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Response of Growth and Toxigenicity to Varying Temperature and Nutrient Conditions in Aphanizomenon flos-aquae (Cyanophyceae) (환경조건에 따른 Aphanizomenon flos-aquae (Cyanophyceae) 균주의 성장 반응 및 독소 생성)

  • Ryu, Hui-Seong;Shin, Ra-Young;Lee, Jung-Ho
    • Journal of Korean Society on Water Environment
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    • v.33 no.5
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    • pp.538-545
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    • 2017
  • The purpose of this study is to investigate growth response and toxigenicity under various temperature and nutritional conditions, in order to understand the physioecological characteristics of Aphanizomenon flos-aquae, which is a bloom-forming cyanobacterium in the Nakdong River. The strain was inoculated into media under combinations of four temperatures (4, 12, 21, $30^{\circ}C$) and three nutrients (modified CB medium, P-depleted CB medium, N-depleted CB medium) for 28 days. The algae-inhibition tests were performed to assess the potential allelopathic effects of the strains' filtrates on the growth of four algae strains (Microcystis aeruginosa, Aulacoseria ambigua f. spiralis, Aphanizomenon flos-aquae, Scenedesmus obliquus). Toxin production of a strain was measured by Enzyme-Linked ImmunoSolbent Assay (ELISA). The optimal growth temperature (Topt) of strains was $19.9^{\circ}C$ ($18.3-21.2^{\circ}C$), and the temperature range for growth was from $-0.3^{\circ}C$ to $34.3^{\circ}C$. Specific growth rate (${\mu}$) in modified CB medium varied from 0.10 to $0.16day^{-1}$, and the maximum growth rate (${\mu}_{max}$) was $0.17day^{-1}$. Although growth curves under N-existed and N-depleted conditions were almost the same, growth under N-depleted condition was relatively slowed (${\mu}=0.09$ to $0.14day^{-1}$), with a decreased maximum cell density. However, growth under the P-depleted condition was restricted for all temperatures, Two stains of Aphanizomenon flos-aquae were confirmed as not producing toxins, because saxitoxin and cylindrospermopsin were not detected by ELISA. The exudates or filtrates from the Aphanizomenon flos-aquae (DGUC003) resulted in significant inhibition of algal growth on the Aulacoseira ambigua f. spiralis (DGUD001) and Aphanizomenon flos-aquae (DGUC001) (p < 0.01).

Characterization and Zoonotic Potential of Uropathogenic Escherichia coli Isolated from Dogs

  • Nam, Eui-Hwa;Ko, Sungjin;Chae, Joon-Seok;Hwang, Cheol-Yong
    • Journal of Microbiology and Biotechnology
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    • v.23 no.3
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    • pp.422-429
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    • 2013
  • The aim of this study was to investigate the characteristics of canine uropathogenic Escherichia coli (UPEC) and the interaction between canine UPEC and human bladder epithelial cells. Ten E. coli isolates collected from dogs with cystitis were analyzed for antimicrobial resistance patterns, the presence of virulence factors, and biofilm formation. The ability of these isolates to induce cytotoxicity, invade human bladder epithelial cells, and stimulate an immune response was also determined. We observed a high rate of antimicrobial resistance among canine UPEC isolates. All virulence genes tested (including adhesins, iron acquisition, and protectin), except toxin genes, were detected among the canine UPEC isolates. We found that all isolates showed varying degrees of biofilm formation (mean, 0.26; range, 0.07 to 0.82), using a microtiter plate assay to evaluate biofilm formation by the isolates. Cytotoxicity to human bladder epithelial cells by the canine UPEC isolates increased in a time-dependent manner, with a 56.9% and 36.1% reduction in cell viability compared with the control at 6 and 9 h of incubation, respectively. We found that most canine UPEC isolates were able to invade human bladder epithelial cells. The interaction between these isolates and human bladder epithelial cells strongly induced the production of proinflammatory cytokines such as IL-6 and IL-8. We demonstrated that canine UPEC isolates can interact with human bladder epithelial cells, although the detailed mechanisms remain unknown. The results suggest that canine UPEC isolates, rather than dogspecific pathogens, have zoonotic potential.