• Journal of Veterinary Science
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• 제21권4호
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• pp.68.1-68.8
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• 2020

A fluorescent microsphere-based immunochromatographic strip test (FICT) was developed for the rapid, sensitive, and quantitative detection of porcine reproductive and respiratory syndrome virus (PRRSV) antibodies at the pen-side. The assay was based on the formation of a sandwich immune-complex (anti-pig IgG-PRRSV antibodies-NSP7/N), which was validated by a comparison with IDEXX-ELISA using 3325 clinical specimens. The diagnostic specificity, sensitivity, and accuracy of FICT were 97.28, 93.41, and 94.95%, respectively. FICT showed a good correlation with the virus neutralization assay. Overall, a promising pen-side diagnostic tool was developed for the rapid and quantitative detection of PRRSV antibodies within 15 min.

• Journal of Microbiology and Biotechnology
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• 제32권7호
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• pp.844-854
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• 2022

Helicobacter pylori, a group 1 carcinogen, colonizes the stomach and affects the development of stomach diseases. Progranulin (PGRN) is an autocrine growth factor that regulates multiple cellular processes and plays a tumorigenic role in many tissues. Nevertheless, the mechanism of action of PGRN in gastric cancer caused by H. pylori infection remains unclear. Here, we investigated the role of PGRN in cell cycle progression and the cell proliferation induced by H. pylori infection. We found that the increased PGRN was positively associated with CDK4 expression in gastric cancer tissue. PGRN was upregulated by H. pylori infection, thereby promoting cell proliferation, and that enhanced level of proliferation was reduced by PGRN inhibitor. CDK4, a target gene of PGRN, is a cyclin-dependent kinase that binds to cyclin D to promote cell cycle progression, which was upregulated by H. pylori infection. We also showed that knockdown of CDK4 reduced the higher cell cycle progression caused by upregulated PGRN. Moreover, when the PI3K/Akt signaling pathway (which is promoted by PGRN) was blocked, the upregulation of CDK4 mediated by PGRN was reduced. These results reveal the potential mechanism by which PGRN plays a major role through CDK4 in the pathological mechanism of H. pylori infection.

• 대한미생물학회지
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• 제21권4호
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• pp.417-422
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• 1986

The specimens were collected from 89 diarrheal patients who had visited Pusan National University Hospital from June to September 1985. They were cultured and tested for the bacteriological identification of causative agents. In this study we identified 5 strains of Salmonella species, 5 strains of Shigella species, 2 strains of Y. enterocolitica, and 17 strains of enteric pathogenic E. coli. Enteric pathogenic E. coli were classified into enterotoxigenic E. coli, enteropathogenic E. coli, and enteroinvasive E. coli by serological type. We tried to isolate V. cholerae and V. parahaemolyticus too but we cannot find them out.

• 한국미생물·생명공학회지
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• 제47권3호
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• pp.459-464
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• 2019

This study aimed to identify and characterize the antimicrobial activity of prodigiosin produced by Serratia sp. $PDGS^{120915}$ isolated from stream water in Busan, Korea; the identification was performed using phonological, biochemical, and molecular techniques, including 16S rRNA sequence analysis. Prodigiosin from the bacterial culture was purified by high-performance liquid chromatography (HPLC), and its antimicrobial activity and minimum inhibitory concentrations (MICs) were evaluated against 10 intestinal pathogenic gram-positive and negative bacteria. The results revealed that the isolated prodigiosin exhibited high antimicrobial activity against Listeria monocytogenes, Bacillus cereus, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus, and Vibrio parahaemolyticus; further, the isolated prodigiosin showed minimum inhibitory concentrations (MICs) between $3{\mu}g/ml$ and 30 mg/ml, but they were not active against Bacillus subtilis, Enterococcus faecalis, Klebsiella pneumonia, and Escherichia coli. In conclusion, prodigiosin isolated from Serratia sp. $PDGS^{120915}$ showed high antimicrobial activity against intestinal pathogenic bacteria and has potential applications in the development of new antimicrobial agents.

• Journal of Microbiology and Biotechnology
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• 제16권3호
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• pp.349-354
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• 2006

Furaneol, a key aroma compound found in strawberry, pineapple, and processed foodstuffs, has been known to possess various biological activities on animal models. In this study, the antimicrobial effects of furaneol against human pathogenic microorganisms were investigated. The results indicated that furaneol displayed a broad spectrum of antimicrobial activities against Gram-positive and Gram-negative bacteria and fungi without hemolytic activity on human erythrocyte cells. To confirm the antifungal activity of furaneol, we examined the accumulation of intracellular trehalose as a stress response marker on toxic agents and its effect on dimorphic transition of Candida albicans. The results demonstrated that furaneol induced significant accumulation of intracellular trehalose and exerted its antifungal effect by disrupting serum-induced mycelial forms. These results suggest that furaneol could be a therapeutic agent having a broad spectrum of antimicrobial activity on human pathogenic microorganisms.

• 한국미생물·생명공학회지
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• 제31권1호
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• pp.32-35
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• 2003

This study was carried out to determine the inhibitory effect of garlic juice against Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhimurium, Shigella flexneri. Staphylococcus aureus, Streptococcus mutans, Virio. parahaemolyticus which are food pathogenic bacteria and Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus casei, Lactobacillus plantarum, Lactococcus. lactis, Leuconostoc mesenteroides which are lactic acid bacteria. An aqueous extract of garlic was bacteriocidal against Gram-positive and Gram-negative bacteria in all concentrations (0.1∼2.5(w/v)%) tested in this experiment. Especially 0.5(w/v)% garlic juice inactivated completely E. coli, S. typhimurium, S. flexineri, V. parahaemolyticus and 1.0(w/v)% garlic juice perfectly reduced P. aeruginosa, S. mutans. Generally, the experiment result indicate that garlic juice restrains the growth of the pathogenic bacteria better than the lactic acid bacteria. Therefore, garlic has potential for the preservation of processed foods.

• Journal of Microbiology and Biotechnology
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• 제17권7호
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• pp.1191-1197
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• 2007

The detection and kinetics of mucosal pathogenic bacteria binding on polysaccharide ligands were studied using a surface plasmon resonance biosensor. The kinetic model applied curve-fitting to the experimental surface plasmon resonance sensorgrams to evaluate the binding interactions. The kinetic parameters for the mucosal pathogenic bacteria (Pseudomonas aeruginosa, Pseudomonas fluorescens, Serratia marcescens) with the alginate ligand were determined from a kinetic model. In addition, the binding interactions of the mucosal pathogenic bacteria with polysaccharide binding pairs (Pseudomonas aeruginosa/alginate, Streptococcus pneumoniae/pneumococcal polysaccharide, Staphylococcus aureus/pectin) were also compared with their kinetic parameters. The rate constants of association for Pseudomonas aeruginosa with the alginate ligand were higher than those for Pseudomonas fluorescens. Serratia marcescens had no detectable interaction with the alginate ligand. The adhesion affinity of Pseudomonas aeruginosa with alginate was higher than that for the other binding pairs. The binding affinities of the pathogenic bacteria with their own polysaccharide were higher than that of Staphylococcus aureus with pectin. Measuring the contact angle was found to be a feasible method for detecting binding interactions between analytes and ligands.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2003년도 2003 Annual Meeting, BioExhibition and International Symposium
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• pp.154-154
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• 2003

• 미생물학회지
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• 제50권4호
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• pp.285-295
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• 2014

병원성 대장균은 최근 3년간 경기도에서 발생한 학교급식식 중독의 주된 원인균으로서 그 역학적 특성을 정리하고 PFGE typing과 항생제 감수성 시험으로 분리균주의 특성을 알아보고자 하였다. 2010년부터 2012년까지 19건의 학교급식 식중독에 대한 역학조사보고서를 분석한 결과, 급식의 주된 운영방식은 직영(18건, 95%)이며, 고등학교에서 주로 발생하였다. 계절적 요인으로는 13건(65%)이 6월부터 9월에, 특히 여름방학 후 학기 초인 8월말부터 9월에 더 많이 발생하였다. 수요일(7건, 37%)과 목요일(7건, 37%)에 최초환자가 발생되어, 목요일 7건(37%) 금요일 5건(26%)에 주로 신고가 이루어 졌다. 추정위험에는 월요일(4건, 21%), 화요일(7건, 37%), 수요일(4건, 21%)에 노출되었고, 추정원인체로서 가능성이 높은 식품은 김치류가 50%(5건)를 차지하였다. 분리된 98균주는 EPEC, ETEC, EAEC, EHEC가 각각 50%, 34%, 15%, 1%이며, 항생제 감수성 시험 결과 ampicillin, nalidixic acid, sulfamethoxazole/trimethoprim, tetracycline에 대하여 각각 40%, 37%, 24%, 19%의 내성을 나타내었고, 2, 3세대 cephalosporins계, cabarpenem계, aminoglycosides계, 2세대 quinolones계 항생제에는 감수성이 있었으며, cefalotin, ampicillin/sulbactam, chloramphenicol에는 각각 29%, 25%, 6%가 중간내성을, 그리고 70%에서 한 가지 이상의 항생제에 내성이 관찰되었다. PFGE 분석결과, 57.6%의 similarity로 8개의 group과 32개의 profiles로 분류되었다. 개별적인 소규모 식중독에서 항생제 감수성과 유전자형의 연관성을 찾기가 어려웠으며, 동시에 발생한 대규모 식중독의 경우, 항생제 내성과 PFGE 유형이 매우 유사하여 동일 기원으로부터 유래한 병원성대장균에 의해 식중독 사고가 발생한 것으로 추정이 가능하였다.

• Journal of Microbiology and Biotechnology
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• 제5권6호
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• pp.324-334
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• 1995

The actinomycete strain A 11 was antagonistic to plant pathogenic fungi Phytophthora capsid and Magnaporthe grisea. Based on the diaminopimelic acid (DAP) type and morphological characteristics examined by scanning electron microscopy, the strain A 11 was confirmed to belong to the genus Streptomyces. Based on Willcox probability and similarity level, the strain A 11 was numerically identified as Streptomyces flaveus using TAXON program of Ward and Goodfellow. Antibiotic production of S. flaveus strain A 11 was most favorable when cultured on glycerol yeast extract peptone (GYP) agar for 20 days at $28^{\circ}C$. The crude antibiotics from solid GYP agar cultures of the strain A 11 were most effective against Phytophthora capsici and Sclerotinia sclerotiorum among the fungi tested. Antifungal activity of the antibiotics against Alternaria solani, Botryosphaeria dothidea, Cercospora capsici, Magnaporthe grisea, and Rhizoctonia solani was somewhat high, whereas Colletotrichum gloeosporioides and Fusarium oxysporum f. sp. cucumerinum were rarely inhibited even at high concentrations.