• BMB Reports
• /
• v.41 no.7
• /
• pp.537-541
• /
• 2008

Epilepsy is characterized by the presence of spontaneous episodes of abnormal neuronal discharges and its pathogenic mechanisms remain poorly understood. Recently, we found that the expression of creatine kinase (CK) was markedly decreased in an epilepsy animal model using proteomic analysis. A human CK gene was fused with a HIV-1 Tat peptide to generate an in-frame Tat-CK fusion protein. The purified Tat-CK fusion protein was efficiently transduced into PC12 cells in a time- and dose-dependent manner when added exogenously to culture media. Once inside the cells, the transduced Tat-CK fusion protein was stable for 48 h. Moreover, the Tat-CK fusion protein markedly increased endogenous CK activity levels within the cells. These results suggest that Tat-CK provides a strategy for the therapeutic delivery of proteins in various human diseases including the delivery of CK for potential epilepsy treatment.

• The Korean Journal of Mycology
• /
• v.41 no.3
• /
• pp.192-196
• /
• 2013

Fungal development is largely affected by many environmental factors. In a model filamentous fungus Aspergillus nidulans, asexual development is promoted by exposure of light, presence of salt and non-fermentable sugars. In other hand, sexual development is largely induced by absence of light, fermentable sugars and hypoxic condition. Also, some important genes including veA and nsdD play positive roles in activating sexual development. Here, we reported that the effect of high concentration of $CO_2$ on developmental decision in A. nidulans. When wild-type $veA^+$ strain was cultured in normal condition, sexual and asexual development occurred in balanced manner. However, high concentration of $CO_2$ (~5%) strongly activated sexual development and inhibited asexual development. Furthermore, this $CO_2$ effect was controlled by the veA or nsdD gene. High $CO_2$ culture of $veA^-$ or $nsdD^-$ mutant didn't activate sexual development, suggesting that the activation of sexual development induced by high $CO_2$ cannot overcome the genetic requirement of sexual development such as veA or nsdD. Since 5% $CO_2$ is an important condition for human pathogenic fungi for surviving and adapting in human body, this developmental pattern of A. nidulans affected by $CO_2$ concentration may provide interesting clues for comparative study with human fungal pathogens including Aspergillus fumigatus.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.2
• /
• pp.318-326
• /
• 2002

The pathogenic marine bacterium Vibrio vulnificus is the causative agent of food-borne diseases such as life-threatening septicemia. To better understand this organism's strategies to survive osmotic stress, a mutant that was more sensitive to high osmolarity was screened from a library of mutants constructed by a random transposon mutagenesis. By a transposon-tagging method, putAP genes encoding a proline dehydrogenase and a proline permease were identified and cloned from V. vulnificus. The amino acid sequences deduced from nucleotide sequences of putAP from V. vulnificus were 38 to $59\%$ similar to those of PutA and PutP reported from other Enterobacteriaceae. Functions of putAP genes were assessed by the construction of mutants, whose putAP genes were inactivated by allelic exchanges. When proline as the sole carbon or nitrogen source was used, the putA mutant was not able to grow to the substantial level, revealing the proline dehydrogenase is the only enzyme for metabolic conversion of proline into other amino acids. Although the growth rate of the putP mutant on proline as the sole carbon or nitrogen source was significantly reduced, the mutant still grew. This indicated that at least one more proline permease is produced by V. vulnificus. The putP mutant decreased approximately $2-log_10$ CFU/ml after a hyperosmotic challenge, while the parent strain decreased approximately $l-log_10$ CFU/ml. This result suggests that the gene product of putP contributes to the osmotic tolerance of V. vulnificus.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.3
• /
• pp.232-239
• /
• 2009

This research investigated the characteristics of antibiotic resistance of bacteria in microbial communities from municipal wastewater treatment plants (MWTPs), and monitored seasonal changes of antibiotic resistant bacteria (ARB) from MWTPs and Han river. When antibiotics were amended to either R2A agar (R2A) for general heterotrophs or MacConeky sorbitol agar (MSA) for coliform bacteria, all the MWTP samples exhibited multiple antibiotic resistance on the antibiotic-amended solid media. The antibiotic resistance appearing frequencies of ampicillin and sulfathiazole, respectively, were higher than reported data for other countries. The antibiotic resistance appearances differed depending upon the concentrations of primary substrate and nutrients and the types of cultivation media. The following 16S rRNA gene phylogenetic analysis showed that the identified multiple-antibiotic resistant microbes on R2A plates were more likely to be known human-pathogenic bacteria than the background heterotrophic bacteria were, suggesting a high risk of antibiotic resistance appearance to public health. In addition, according to our investigation of seasonal changes of ARB from urban MWTP and river samples, the frequency of ARB appearances was shown to correlate positively with temperature. This indicates a possibility that global warming result in increase in microbial risk to public health.

• Allergy, Asthma & Immunology Research
• /
• v.10 no.6
• /
• pp.698-715
• /
• 2018

Purpose: Hrd1 has recently emerged as a critical regulator of B-cells in autoimmune diseases. However, its role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) remains largely unexplored. This study aimed to examine Hrd1 expression and B-cell accumulation and their possible roles in CRSwNP. Methods: Quantitative real-time polymerase chain reaction, immunohistochemistry, enzyme-linked immunosorbent assay and Western blotting were used to assess gene and protein expression in nasal tissue extracts. Cells isolated from nasal tissues and peripheral blood mononuclear cells were characterized by flow cytometry. Local antibody production was measured in tissue extracts with a Bio-Plex assay. Additionally, changes in Hrd1 expression in response to specific inflammatory stimuli were measured in cultured dispersed polyp cells. Results: Nasal polyps (NPs) from patients with eosinophilic CRSwNP (ECRS) had increased levels of Hrd1, B-cells and plasma cells compared with NPs from patients with non-eosinophilic CRSwNP (non-ECRS) or other control subjects (P < 0.05). The average Hrd1 levels in B-cells in NPs from ECRS patients were significantly higher than those from non-ECRS patients and control subjects (P < 0.05). NPs also contained significantly increased levels of several antibody isotypes compared with normal controls (P < 0.05). Interestingly, Hrd1 expression in cultured polyp cells from ECRS patients, but not non-ECRS patients, was significantly increased by interleukin-$1{\beta}$, lipopolysaccharide and Poly(I:C) stimulation, and inhibited by dexamethasone treatment (P < 0.05). Conclusions: Differential Hrd1 expression and B-cell accumulation between the ECRS and non-ECRS subsets suggests that they can exhibit distinct pathogenic mechanisms and play important roles in NP.

• Journal of Applied Biological Chemistry
• /
• v.63 no.4
• /
• pp.387-392
• /
• 2020

Pseudomonas tolaasii is a pathogen causing brown blotch disease in cultivated mushrooms. In previous study, various strains of P. tolaasii were isolated from the mushrooms with disease symptoms and they were further divided into Ptα, Ptβ, and Ptγ subtypes according to the 16S rRNA gene analysis. To investigate the secretion of peptide toxins, tolaasin and its analog peptides, culture extracts of Pt group strains were analyzed by gel permeation chromatography. Those of Ptα subtype strains contained two chromatographic peaks, band A and B. Meanwhile, those of Ptβ and Ptγ subtype strains contained mainly band A component and a little of band B. Molecular weights of toxic peptides of culture extracts were measured by MALDI-TOF mass spectrometry. In Ptα subtype strains, the peptide compositions of band A and B were same including tolaasin I (1,987 Da), tolaasin II (1,943 Da), and its two analog peptides, 1,973 Da and 2,005 Da. The strains of Ptβ and Ptγ subtype secreted many components of MW 1,100-1,200 Da, but they did not synthesize any tolaasin-like peptides. These results suggest that the only Ptα subtype strains secrete tolaasin and its analog peptide toxins and the strains of Ptβ and Ptγ subtypes have different pathogenic characters causing brown blotch disease.

• Journal of Marine Life Science
• /
• v.1 no.1
• /
• pp.18-24
• /
• 2016

Since April 2012, doctor fish in the breeding tank and in the quarantine tank in Hanwha Aquaplanet Yeosu Aquarium have been dying, accompanied by diffuse bleeding around the mouth, in the chin, and at the bottom of the abdomen. In this study, the cause of death would be examined through the bacteriological study of doctor fish and the rearing water quality in the aquarium. The water quality and the bacterial counts of the rearing water in the exhibit tank and in the quarantine tank were analyzed once a week, starting from August to November 2014. Water quality was measured based on the following data: temperature was in the range of 24.5~26.8℃, pH at 6.77~7.94, DO at 6.15~8.61 ppm, ammonia at 0~0.93 ppm, nitrite at 0.009~0.075 ppm, and nitrate at 1.1~40.9 ppm. Studies revealed that the differences in these water quality factors were not related to the death of doctor fish. Bacterial counts in the rearing waters of Garra rufa slightly increased to 10³~10⁴ CFU/ml, just before the death of the doctor fish. Twelve strains of bacteria were isolated from the dead fish and rearing waters. The isolates were identified as Aeromonas veronii, Citrobacter freundii, Pseudorhodoferax aquiterrae, Shewanella putrefaciens, and Vibrio anguillarum on the basis of 16S rRNA gene sequences. The most dominant species was C. freundii, which showed medium sensitivity to florfenicol and norfloxacin, and was resistant to amoxacillin, doxycycline, oxytetracycline, tetracycline, and trimethoprim. Ten isolates were confirmed to be pathogenic to the doctor fish. Doctor fish infected with C. freundii and S. putrefaciens showed high mortality in the experimental groups. These results indicate that the variation in bacterial numbers in the rearing water was related to the death of doctor fish. C. freundii and S. putrefaciens were directly implicated in causing the death of doctor fish in the aquarium.

• Journal of fish pathology
• /
• v.30 no.2
• /
• pp.89-96
• /
• 2017

The majority of freshwater ornamental fish are imported and distributed domestically, causing high risk of exposure to exotic pathogens and drug resistant bacteria in Korea. Aeromonas hydrophila is known as a common species of fresh water bacteria and opportunistic fish pathogen, as well as a species causing zoonotic infection. In this study, we isolated motile aeromonads from various imported freshwater ornamental fish and studied the characters of the isolates. Imported freshwater ornamental fish were purchased on day 1 after the fish were deposited in the aquarium. Bacteria were isolated from the liver, kidney and spleen of fish using 0.5% NaCl containing tryptic soy agar medium. Bacteria were grouped on the basis of their morphological characteristics. The colonies with clear zone on starch-ampicillin agar (SA agar) were tentatively identified as Aeromonas spp. Two hundred and twenty-six strains, about 70% of total isolates were assumed to be Aeromonas spp. Nine isolates were further identified based on the result of the API 20E test and PCR using primers specific for A. hydrophila 16S rRNA gene. The isolates were identified as A. hydrophila and the API 20E test showed differences in trisodium citrate, D-sucrose, D-melibiose, amygdalin and L-arabinose availability between the nine isolates and standard A. hydrophila. The susceptibilities of the isolated bacteria to 10 antibacterial agents were confirmed by the disk diffusion method. Isolated strains were found to be resistant to amoxicillin and ampicillin and sensitive to florfenicol. However, 7 isolates showed multiple drug resistances to erythromycin, oxytetracycline, nalidixic acid etc. Pathogenicity of the isolates was determined by the artificial challenge test on goldfish (Carassius auratus). Three isolates caused 60 ~ 80% mortality in goldfish within 5 days after the initiation of challenge. These results indicate that multiple drug resistant, highly pathogenic and exotic A. hydrophila can spread to domestic aquarium and the preventive treatment of fish before sale is necessary.

• Korean Journal of Soil Science and Fertilizer
• /
• v.26 no.4
• /
• pp.271-277
• /
• 1993

An antagonistic bacteria was isolated from rhiaosphere of pepper and corn and identified as Bacillus (B.) subtilis. These B. subtilis B-5 was transformed and marked with the plasmid pCPP4 which possess neomycine resistan. gene. The marked stranins showed growth inhibition to Rhizoctonia (R.) solani, Fusarium (F.) solani, and F. oxysporum in vitro, and were used in studying growth promoting effects on sesame and cabbage. All the identified strains utilize glucose, sucrose, fructose, lactose, mannitol and sorbitol as carbon source, but not rhamnose, and the marked strains also showed characteristics similar to wild-type strains. Germination rate of chinese cabbage and sesame seeds was increased by about 10% or more in the plot to which these strains were inoculated and the effect was higher in soil than in petri dish. The early growth promoting effects of these strains appeared higher, as compared with control plot, in the plots to which B. subtilis B-5 and pathogenic fungi was inoculated together. When the marked strains, B. subtilis B-5NEOr, were inoculated in the rhizosphere of chinese cabbage and sesame with $1.1{\times}10^8CFU/g$ dry soil, the number of inoculated strain was decreased slowly to the level of $10^5{\sim}10^6CFU/g$ dry soil after 4 weeks and the number of Pseudomonas spp. maintanied the level of $10^5CFU/g$ dry soil throught total period, but the number of fungi was decreased rapidly from the early level of $10^8CFU/g$ dry soil to $10^3CFU/g$ dry soil after 4 weeks.

• Korean Journal of Food Science and Technology
• /
• v.49 no.6
• /
• pp.599-604
• /
• 2017

The purpose of this study was to explore methods for efficient management of the quality and safety of simple processed agricultural products in Busan. We tested 258 samples of simple processed agricultural products for distribution of aerobic bacteria and coliforms, and identified food-borne pathogens. The average aerobic bacterial and coliforms counts were 7.1 and 4.1 log CFU/g in simple processed vegetables, 6.8 and 3.5 log CFU/g in dried vegetables, and 6.2 and 2.9 log CFU/g in simple processed fruits. Additionally Staphylococcus aureus, Salmonella spp., Campylobacter jejuni/coli and Listeria monocytogenes were not detected in any samples. However, Bacillus cereus, Clostridium perfringens and E. coli were detected in 41 samples (16.3%), 2 samples (0.8%), and 4 samples (1.6%), respectively. This analysis revealed that none of C. perfringens and E. coli isolates harbored pathogenic toxic genes. However, all of B. cereus isolates carried at least 1 toxin gene.