• Biomedical Science Letters
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• 제19권2호
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• pp.142-146
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• 2013

Enterotoxigenic Bacteroides fragilis (ETBF) causes inflammatory diarrhea in humans and animals and is also implicated in colorectal cancer. ETBF-infected mice exhibit a prominent large intestinal inflammation characterized by neutrophil infiltration and induction of the Th17 response. In this study, we examined differences in the secreted cytokine profile of the cecum and proximal colon of ETBF-infected mice using an antibody array. Of the cytokines examined, we found that the cecal tissues from ETBF-infected mice secreted elevated levels of G-CSF, IL-6, IL-17 and LIX compared to non-toxigenic Bacteroides fragilis (NTBF) and Mock infected mice. The proximal colon tissues from ETBF-infected mice secreted higher levels of G-CSF, IL-6, KC, LIX, MIP-1g and MCP-1. This study demonstrates that the cecum and colon should be considered separately when assays are used to determine immune responsiveness to enteric infections.

• Journal of Environmental Health Sciences
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• 제35권2호
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• pp.95-99
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• 2009

This study was performed to investigate the possible effect of garlic produced in Korea on the inhibition/reduction of growth of A. parasiticus, a toxigenic strain. The effect was studied using different concentrations of freeze-dried garlic in potato-dextrose agar (PDA) and/or in yeast-extract sucrose (YES) broth at $25^{\circ}C$ for 15 days. While inhibition of the fungal growth due to increasing the concentration of garlic was observed, the more remarkable effect was observed on the ninth day. Reduction of fungal diameter as a result of addition of garlic on PDA was observed to range between 3.4% to 20.1 % while reduction of mycelial weight in YES broth ranged from 9.9% to 30.5%. The 0.5% and 1.0% concentrations of garlic significantly reduced fungal diameter in PDA on the 9th day, while 0.1 %, 0.5%, and 1.0% concentrations of garlic significantly reduced the mycelial weight in YES broth (p<0.05). Dose-response relationships were observed between the concentration of garlic and inhibition of growth both in solid culture and in liquid culture. This study indicates that garlic could be an effective inhibitor at a human consumption level of the growth of A. parasiticus. More research is needed to study the inhibitory effects of the main active component of garlic.

• Food Science and Biotechnology
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• 제15권2호
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• pp.232-237
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• 2006

Bacillus cereus group comprising B. cereus, B. thuringiensis, and B. mycoides was differentiated by polymerase chain reaction (PCR) and colony morphology. Prevalence of B. cereus group in rice and distribution of enterotoxin genes were determined as possible food poisoning agents. PCR using primers targeted for gyrB and cry genes could distinguish B. thuringiensis from B. cereus, and B. mycoides was differentiated by rhizoid morphological characteristics on nutrient agar. Among 136 rice and their processed products, prevalence of B. cereus group was 40%. B. cereus group consisted of 54 B. cereus, 11 B. thuringiensis, and 1 B. mycoides. Major isolates were B. cereus, with B. thuringiensis detected up to 10% among edible rice tested. Five enterotoxin genes, hbl, nhe, bceT, entFM, and cytK, were broadly distributed among B. cereus group, especially in B. cereus and B. thuringiensis. Prevalence of B. cereus group in rice and enterotoxin distribution suggest B. thuringiensis and B. cereus are toxigenic strain that should be controlled in rice and its products.

• Korean Journal of Microbiology
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• 제12권2호
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• pp.59-68
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• 1974

With an aim to disclose causal factors scably grains intoxications, the screening of toxic Fusaria and the detection of toxic priniciples were performed in respect of cultured cells bioassay with HeLa cells, skin-necrotizing effect, histopathological investigation and also chromatographic analysis sith following results ; 1. Among the fungi, Fusarium sp. F-27, F-63 and F-61 were highly toxic to mice, causing liver injury characterized necrosis and inflammation. 2. HeLa cell culture bioassay demonstrated that the cell of the isolated strains of Fusaria were suspected to produce toxic material (Fusarenon-X). 3. The culture filtrates of Fusarium nivale Fn-2B, F-27, and F-63, were injected subcutaneously, and caused inflammation followed by crust on the skin ICR-mice. 4. The observation method of skin-necrotizing effect to the mice can be used to the screening to the toxin-producing fungi isolated from many fusarial contaminations.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제37권3호
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• pp.202-208
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• 2004

The spatio-temporal distribution of dinoflagellate resting cysts was investigated by palynological processing to understand the harmful algal bloom (HAB) potential in the sediment of the Saemangeun area in 2003. In total, thirty-two dinoflagellate species were identified, and their concentrations were in the range of $6-1,618\;cysts{\cdot}g^{-1}$ (dry weight). The concentrations of resting cysts were higher in the spring (26 species, $64-1,101\;cysts{\cdot}g^{-1})$ and summer (30 species, $81-1,618\;cysts{\cdot}g^{-1})$ than in the autumn (32 species, $6-1,150\;cysts{\cdot}g^{-1})$ and winter (24 species, $25-728\;cysts{\cdot}g^{-1}).$ The composition rate of the heterotrophic dinoflagellate species to the total, which is closely related to the eutrophication process, to ranged from 6 to $29\%$ in the study area. The most dominant species was toxic Alexandrium tamarense/catenella $(25\%)$ followed by Gonyaulax scrippsea $(9\%)$ and toxic Protoceratium reticulatum $(5\%).$ Given the high abundance of the toxigenic dinoflagellate species, the Saemangeun area is considered to have the great potential for HABs in the future.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1756-1763
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• 2010

Pasteurella multocida serogroup D strain, which produces P. multocida toxin (PMT), is a widespread and harmful pathogen of respiratory diseases such as pneumonia and progressive atrophic rhinitis (PAR) in swine. Vaccination has been considered the most desirable and effective approach for controlling the diseases caused by toxigenic P. multocida. To investigate the antigenicity and immunogenicity of partial fragments of recombinant PMT, recombinant proteins of the N-terminal (PMT-A), middle (PMT-B), C-terminal (PMT-C), and middle-C-terminal (PMT2.3) regions of PMT were successfully produced in an Escherichia coli expression system. The molecular masses of PMT-A, PMT-B, PMT-C, and PMT2.3 were ca. 53, 55, 35, and 84 kDa, respectively, purified by nickel-nitrilotriacetic acid (Ni-NTA) affinity column chromatography. All the recombinant proteins except for PMT-A showed immune responses to antisera obtained from a swine showing symptoms of PAR. Moreover, high titers of PMT-specific antibodies were raised from mice immunized with each of the recombinant proteins; however, the immunoreactivities of the antibodies to authentic PMT and heat-inactivated whole bacteria were different, respectively. In the protection study, the highest protection against homologous challenge was shown in the case of PMT2.3; relatively poor protections occurred for the other PMT fragments.

• Journal of Environmental Science International
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• 제14권7호
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• pp.649-655
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• 2005

Microcystis aeruginosa is common form of cyanobacteria (blue-green algae) capable of producing toxic heptapeptide (microcystin) that cause illness or death. The comparison of molecular genetic method with the morphological characteristics of cyanobacteria was conducted. We have designed PCR primers (JJM98F, JJM1141R) for cyanobacterial 16S rRNA and phycocyanin intergenic spacer (PC-IGS) gene domain. To confirm the production of microcystins, PCR primers for the N-methyltransferase (NMT) domain of microcystin synthetase gene mcyA were designed using 21 cyanobacteria strains Most of isolated strains from the Nakdong River was classified as Microcystis aeruginosa and the similarities were $99\%$ with M. aeruginosa AF 139292. $38.1\%$ of isolated strains contained microcystin synthesis gene. NMT (N-methyltransferase) were not detected in isolated strain in several strains, which means non-toxic. However, the NMTs of the strains were detected during the cultivation.

• Journal of Microbiology and Biotechnology
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• 제22권2호
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• pp.248-255
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• 2012

In order to develop a protocol to quantify cyanobacteria and Microcystis simultaneously, the primers and probe were designed from the conserved regions of 16S rRNA gene sequences of cyanobacteria and Microcystis, respectively. Probe match analysis of the Ribosomal Database Project showed that the primers matched with over 97% of cyanobacterial 16S rRNA genes, indicating these can be used to amplify cyanobacteria specifically. The TaqMan probe, which is located between two primers, matched with 98.2% of sequences in genus GpXI, in which most Microcystis strains are included. The numbers of cyanobacterial genes were estimated with the emission of SYBR Green from the amplicons with two primers, whereas those of Microcystis spp. were measured from the fluorescence of CAL Fluor Gold 540 emitted by exonuclease activity of Taq DNA polymerase in amplification. It is expected that this method enhances the accuracy and reduces the time to count cyanobacteria and potential toxigenic Microcystis spp. in aquatic environmental samples.

• Journal of Veterinary Clinics
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• 제34권2호
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• pp.112-114
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• 2017

Two one-month-old dairy calves which have Eimeria oocysts in their bloody diarrhea died acutely a few days after showing the first clinical signs. At necropsy, hemorrhagic and congestive gastrointestinal organs were observed in both calves, and abomasal ulcerations existed. As a prevalent agent in all of the collected intra-intestinal specimens, Clostridium perfringens was isolated and the strain was identified as type A possessing alpha and beta2-toxins. In these clinical cases, intercurrent infection by C. perfringens type A and Eimeria through contaminated environment may be responsible for acute hemorrhagic enteritis.

• Korean Journal of Microbiology
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• 제54권3호
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• pp.214-221
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• 2018

Clostridium difficile infection (CDI) is a rapidly emerging infection that may have devastating consequences. Prompt and accurate diagnosis is crucial for management and control. The aim of this study was to determine the incidence of C. difficile associated diarrhea among hospitalized patients, and to compare different diagnostic laboratory methods for detection of toxin producing strains in clinical specimens. The study was conducted at a university hospital in Cairo during the period from May 2013 till June 2015. Subjects were under antibiotic therapy and presented with hospital-acquired diarrhea. Four hundred and sixty-five stool specimens were processed by different microbiological methods. C. difficile was recovered in culture in 51 of stool specimens. Of these, 86.3% to 98% were positive for toxin production by 2 different methods. This study showed that antibiotic intake is the major risk factor for development of hospital-acquired diarrhea. We evaluated different microbiological methods for diagnosis of C. difficile. We recommend the use of toxigenic culture as a gold standard for microbiological diagnosis of C. difficile.