• Journal of Microbiology and Biotechnology
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• v.25 no.10
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• pp.1728-1733
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• 2015

This study was done to establish a mouse model for catheter-related biofilm infection suitable to bioluminescence imaging (BLI). Biofilm formation of Pseudomonas aeruginosa (P. aeruginosa) Xen5 grown on catheter disks in vitro and in an implanted mouse model was real-time monitored during a 7-day study period using BLI. The numbers of integrated brightness (IB) and viable bacterial count (VBC) in the biofilm disks in vitro were highest at 24 h after inoculation; the IB of biofilm in vivo was increased until 24 h after implantation. A statistical correlation was observed between IB and VBC in vitro by linear regression analysis. The actual VBC value in vivo can be estimated accurately by IB without sacrifice. In addition, we monitored the change in white blood cells (WBCs) during infection. The number of WBCs on day 7 was significantly higher in the infection group than in the control group. This study indicates that BLI is a simple, fast, and sensitive method to measure catheter biofilm infection in mice.

• Korean Journal of Veterinary Research
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• v.40 no.1
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• pp.145-152
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• 2000

This study was performed to study the sequential clinical and pathologic changes of Korean isolate KBA-2 of Neospora caninum in SCID mice following intraperitoneal infection. Also the results of PCR and in vitro isolation was compared during the study. The infection appears to be disseminated hematogenously, when the infection was chased every 3days up to 21 days following infection. The PCR method was determined to be more effective than in vitro isolation regarding early detection of the organism follwing infection.

• The Plant Pathology Journal
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• v.39 no.2
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• pp.181-190
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• 2023

The fungal pathogen Pseudocercospora fuligena, known to affect tomatoes in the tropics and subtropics, has been reported from temperate climates including the United States and Turkey in recent years. In this study, an isolate from fresh tomatoes and the disease it causes were characterized and infection mechanisms investigated. Macroscopically, both sides of tomato leaves show indistinct effuse patches but prolific production of fuliginous lesions is conspicuous on the abaxial side first but also on the adaxial side later on as infection progressed. Microscopically, fascicles of conidiophores (11-128 ㎛ × 3.5-9 ㎛) arising from stromata and conidia with up to 12 septations were observed. Molecular characterization of the isolate revealed high homology (99.8%) to other P. fuligena isolated from tomatoes in Turkey. Out of the 10 media tested, P. fuligena grew significantly well and sporulated better on unsealed tomato oatmeal agar and carrot leaf decoction agar, both supplemented with CaCO₃. Direct transfer of conidia from profusely sporulating lesions was the easiest and quickest method of isolation for in-vitro studies. Light and scanning electron microscopy on cleared and intact tomato leaves further confirmed stomatal penetration and egress as well as prevalence of primary and secondary infection hyphae. In situ, blocked stomatal aperture areas of 154, 401, and 2,043 ㎛² were recorded at 7, 12, and 17 days after inoculation, respectively. With the recent expanded horizon of the pathosystem and its consequential impact, such studies will be useful for a proper diagnosis, identification and management of the disease on tomato worldwide.

• Korean Journal of Veterinary Research
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• v.41 no.1
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• pp.89-98
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• 2001

This study was conducted to detect the toxoplasma specific-DNA in circulating blood and organs collected from slaughtered pigs at slaughtering house and experimentally infected pigs with Toxoplasma gondii tachyzoites by polymerase chain reaction(PCR), and also PCR was applied to diagnose for acute phase of swine toxoplasmosis as a newly developed diagnostic test. The sensitivity of oligonucleotide primer, T-1 & T-2, designed from toxoplasma B1 gene amplification method was compared with Tp parasite detection by mouse inoculation(MI). On the other hand, latex agglutination test(LAT) was conducted to detect the serum antibodies comparing with the detection of toxoplasma by PCR and MI. The results obtained were summarized as follows. PCR was able to determine at the lowest level of $10^0/ml$ T. gondii in blood samples which were blended with a serial diluted T gondii in vitro. On the other hand, $10^2/5g$ of T gondii could detect from a variety of tissues including lung, diaphragm, liver, heart, spleen and brain in vitro. The primer was proved to specifically determine T gondii in blood and tissues in vitro but it did not detect Neospora caninum used as a negative control. DNA of T. gondii was effectively extracted by freezing, thawing and grinding twice both tissues mixed with T gondii in vitro and in experimentally infected pig's tissues. PCR detected specific DNA in the blood of experimentally infected pigs at 108 hrs and 120 hrs post-infection, it was the same time that the pigs showed fever and parasitaemia. In case of tissue, specific DNA was, however, detected only lung from experimentally infected pigs. Even though the duration of acute phase was from 3 to 7 days post-infection, but the latex agglutination test (LAT) results appeared from 8 days post-infection. A comparison of sensitivity in determining T gondii in blood samples between PCR and MI, PCR positive rate ranged from 25 to 33.3%, but that of MI covered from 75 to 100%.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5219-5223
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• 2015

Helicobacter pylori (H. pylori) infection as a serious problem in both adults and children can induce chronic gastritis, peptic ulcer disease (PUD), and possibly gastric cancer. The aim of the current study was to survey antibiotic resistance and also to determine influence of PPAR$\gamma$ polymorphism in patients with H. pylori infection. During an 11-month-period, 98 H. pylori isolates were collected from 104 biopsy specimens. In vitro susceptibility of H. pylori isolates to 4 antimicrobial agents metronidazole, clarithromycin, amoxicillin and tetracycline were assessed by quantitative method according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guideline. PPAR$\gamma$ polymorphism was determined using polymerase chain reaction-restriction fragment length polymorphism assay. The frequency of H. pylori infection in our study was 94.2%. In vitro susceptibility data showed that highest level of resistance was related to metronidazole (66.3%), and the majority of H. pylori isolates were highly susceptible to amoxicillin and tetracycline (94.9% and 96.9%, respectively). Genotypic frequencies were 25.5% for CC (Pro12Pro), 40.8% for GC (Pro12Ala) and 33.7% for GG (Ala12Ala). In our study, CG genotype had highest distributions among infected patients with H. pylori. The study suggests that the PPAR-$\gamma$ Pro12Ala polymorphism could be evaluated as a potential genetic marker for susceptibility to gastric cancer in the presence of H. pylori infection.

• Mycobiology
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• v.39 no.3
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• pp.206-218
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• 2011

The seed-borne mycoflora of sorghum and foxtail millet collected from different growing areas in South Korea were isolated and taxonomically identified using dry inspection, standard blotter and the agar plate method. We investigated the in vitro and in vitro germination rates of disinfected and non-disinfected seeds of sorghum and foxtail millet using sterilized and unsterilized soil. The percent recovery of seed-borne mycoflora from the seed components of sorghum and foxtail millet seeds was determined and an infection experiment using the dominant species was evaluated for seedling emergence and mortality. A higher number of seed-borne fungi was observed in sorghum compared to that of foxtail millet. Eighteen fungal genera with 34 fungal species were identified from the seeds of sorghum and 13 genera with 22 species were identified from the seeds of foxtail millet. Five dominant species such as Alternaria alternata, Aspergillus flavus, Curvularia lunata, Fusarium moniliforme and Phoma sp. were recorded as seed-borne mycoflora in sorghum and 4 dominant species (Alternaria alternata, Aspergillus flavus, Curvularia lunata, Fusarium moniliforme) were observed in foxtail millet. The in vitro and in vitro germination rates were higher using disinfected seeds and sterilized soil. More seed-borne fungi were recovered from the pericarp compared to the endosperm and seed embryo. The percent recovery of seed-borne fungi ranged from 2.22% to 60.0%, and Alternaria alternata, Curvularia lunata and 4 species of Fusarium were isolated from the endosperm and embryo of sorghum and foxtail millet. Inoculation of the dominant seed-borne fungi showed considerable mortality of seedlings. All the transmitted seed-borne fungi might well be a primary source of infection of sorghum and foxtail millet crops.

• Food Science of Animal Resources
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• v.36 no.2
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• pp.186-193
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• 2016

This study aimed to inhibit Escherichia coli (E. coli) O157:H7 artificially contaminated in fresh meat using bacteriophage. Among 14 bacteriophages, the highly lytic bacteriophage BPECO19 strain was selected to inhibit E. coli O157:H7 in artificially contaminated meat samples. Bacteriophage BPECO19 significantly reduced E. coli O157:H7 bacterial load in vitro in a multiplicity of infection (MOI)-dependent manner. E. coli O157:H7 was completely inhibited only in 10 min in vitro by the treatment of 10,000 MOI BPECO19. The treatment of BPECO19 at 100,000 MOI completely reduced 5 Log CFU/cm² E. coli O157:H7 bacterial load in beef and pork at 4 and 8h, respectively. In chicken meat, a 4.65 log reduction of E. coli O157:H7 was observed at 4 h by 100,000 MOI. The treatment of single bacteriophage BPECO19 was an effective method to control E. coli O157:H7 in meat samples.

• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.109-109
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• 2002

Detection of protozoan parasites Perkinsus sp. and P. atlanticus was developed in this study using a specific polymerase chain reaction (PCR) to diagnose the presence of those organisms that causes extensive mortalities of marine shellfishes. The PCR was conducted together with fluid thioglycollate medium (FTM) method and 2 M NaOH lysis method. For the test, Manila clams, Ruditapes philippinarum, were collected from four coastal locations in Korea including Wando Island, Gimnyeong, Sungsan and Sogwipo in Jeju. In addition, trophozites of Perkinsus sp. cultivated in vitro and the granular ark clam, Tegillarca granosa, taken from Gangjin on the south coast of Korea, were used as positive and negative controls, respectively. Expected DNA bands were detected in the samples from Wando Island, Sungsan and the in vitro cultured Perkinsus sp. when the probes specific for the genus Perkinsus and P. atlanticus were used. The samples were also positively diagnosed by the FTM and 2 M NaOH methods. In contrast, the Manila clams from Gimnyeong and Sogwipo, and the granular arks clams from Gangjin showed no detectable signs of infection with the PCR, the FTM method and the 2 M NaOH lysis method. On the other hand, being amplified by p. atlanticus specific primer, it is suggested that the protozoan parasite Perkinsus sp. found in the Korean Manila clam is P. atlanticus. Finally the PCR- based assay developed in the present study can be used in detection of Perkinsus infection and discrimination of Peykinsus species in quarantine stations or laboratories due to the high sensitivity and specificity as well as its rapid detection.

• Korean Journal of Environmental Biology
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• v.20 no.2
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• pp.109-117
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• 2002

Detection of protozoan parasites Perkinsus sp. and P. atlanticus was developed in this study using a specific polymerase chain reaction (PCR) to diagnose the presence of those organisms that causes extensive mortalities of marine shellfishes. The PCR was conducted together with fluid thioglycollate medium (FTM) method and 2 M NaOH lysis method. For the test, Manila clams, Ruditapes philippinarum, were collected from four coastal locations in Korea including Wando Island, Gimnyeong, Sungsan and Sogwipo in Jeju. In addition, trophozites of Perkinsus sp. cultivated in vitro and the granular ark clam, Tegillarca granosa, taken from Gangjin on the south coast of Korea, were used as positive and negative controls, respectively. Expected DNA bands were detected in the samples from Wando Island, Sungsan and the in vitro cultured Perkinsus sp. when the probes specific for the genus Perkinsus and P. atlanticus were used. The samples were also positively diagnosed by the FTM and 2 M NaOH methods. In contrast, the Manila clams from Gimnyeong and Sogwipo, and the granular arks clams from Gangjin showed no detectable signs of infection with the PCR, the FTM method and the 2 M NaOH lysis method. On the other hand, being amplified by p. atlanticus specific primer, it is suggested that the protozoan parasite Perkinsus sp. found in the Korean Manila clam is P. atlanticus. Finally the PCR- based assay developed in the present study can be used in detection of Perkinsus infection and discrimination of Peykinsus species in quarantine stations or laboratories due to the high sensitivity and specificity as well as its rapid detection.

• Nutrition Research and Practice
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• v.11 no.1
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• pp.11-16
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• 2017

BACKGROUND/OBJECTIVES: Helicobacter pylori (H. pylori) colonization of the stomach mucosa and duodenum is the major cause of acute and chronic gastroduodenal pathology in humans. Efforts to find effective anti-bacterial strategies against H. pylori for the non-antibiotic control of H. pylori infection are urgently required. In this study, we used whey to prepare glycomacropeptide (GMP), from which sialic acid (G-SA) was enzymatically isolated. We investigated the anti-bacterial effects of G-SA against H. pylori in vitro and in an H. pylori-infected murine model. MATERIALS/METHODS: The anti-bacterial activity of G-SA was measured in vitro using the macrodilution method, and interleukin-8 (IL-8) production was measured in H. pylori and AGS cell co-cultures by ELISA. For in vivo study, G-SA 5 g/kg body weight (bw)/day and H. pylori were administered to mice three times over one week. After one week, G-SA 5 g/kg bw/day alone was administered every day for one week. Tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), IL-$1{\beta}$, IL-6, and IL-10 levels were measured by ELISA to determine the anti-inflammatory effects of G-SA. In addition, real-time PCR was performed to measure the genetic expression of cytotoxin-associated gene A (cagA). RESULTS: G-SA inhibited the growth of H. pylori and suppressed IL-8 production in H. pylori and in AGS cell co-cultures in vitro. In the in vivo assay, administration of G-SA reduced levels of IL-$1{\beta}$ and IL-6 pro-inflammatory cytokines whereas IL-10 level increased. Also, G-SA suppressed the expression of cagA in the stomach of H. pylori-infected mice. CONCLUSION: G-SA possesses anti-H. pylori activity as well as an anti-H. pylori-induced gastric inflammatory effect in an experimental H. pylori-infected murine model. G-SA has potential as an alternative to antibiotics for the prevention of H. pylori infection and H. pylori-induced gastric disease prevention.