• Journal of Microbiology and Biotechnology
• /
• 제25권10호
• /
• pp.1728-1733
• /
• 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.

• 대한수의학회지
• /
• 제40권1호
• /
• pp.145-152
• /
• 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
• /
• 제39권2호
• /
• pp.181-190
• /
• 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.

• 대한수의학회지
• /
• 제41권1호
• /
• pp.89-98
• /
• 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
• /
• 제16권13호
• /
• pp.5219-5223
• /
• 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
• /
• 제39권3호
• /
• pp.206-218
• /
• 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.

• 한국축산식품학회지
• /
• 제36권2호
• /
• pp.186-193
• /
• 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.

• 환경생물
• /
• 제20권1호
• /
• pp.109-109
• /
• 2002

이 연구에서는 해산 연체동물의 폐사를 유발하는 기생성 원생동물인 Perkinsus를 신속하고 특이적으로 검출하기 위하여 PCR 진단법을 개발하였다. 이를 위해 Perkinsus 속 4종을 공통적으로 증폭하거나 P. atlanticus만을 특이적으로 증폭할 수 있는 두 가지의 primer를 제작하였다. PCR분석은 기존 Perkinsus 진단법인 fluid thioglycollate medium (FTM) 방법과 2 M NaOH 기법을 병행하여 실시하였다. 실험구로서 전라남도 완도산, 제주도 김녕산, 제주도 서귀포산, 제주도 성산산 바지락과 in vitro 배양된 바지락포자충이 이용되었으며, 대조구로서 전라남도 강진에서 채집된 꼬막, T. granosa을 사용하였다. 실험 결과 Perkinsus특이성 DNA band가 전남 완도산과 제주도 성산산 바지락, in vitro 배양된 바지락 포자충에서 확인되었으나, 대조구였던 꼬막과 제주도 서귀포산, 제주도 김녕산 바지락에서는 나타나지 않았다. 이같은 진단 결과는 FTM과 2M NaOH 진단 결과와 일치하였다. 한편 P. atlanticus에 특이적인 primer에 의해 증폭된 band가 확인됨에 따라 국내산 바지락에서 검출되는 바지락포자충은 P. atlanticus와 동일 종임이 확인되었다. 결론적으로, 본 연구를 통하여 개발된 PCR을 이용한 진단법은 해산 연체동물내 Perkinsus 속 기생충과 P. atlanticus의 감염을 신속하고도 종 특이적으로 진단할 수 있어 수ㆍ출입 수산물의 검역과 바지락 포자충의 생태학적 특성을 규명하는데 효과적으로 이용될 수 있을 것으로 기대된다.

• 환경생물
• /
• 제20권2호
• /
• pp.109-117
• /
• 2002

이 연구에서는 해산 연체동물의 폐사를 유발하는 기생성 원생동물인 Perkinsus를 신속하고 특이적으로 검출하기 위하여 PCR 진단법을 개발하였다. 이를 위해 Perkinsus 속 4종을 공통적으로 증폭하거나 P. atlanticus만을 특이적으로 증폭할 수 있는 두 가지의 primer를 제작하였다. PCR분석은 기존 Perkinsus 진단법인 fluid thioglycollate medium (FTM) 방법과 2 M NaOH 기법을 병행하여 실시하였다. 실험구로서 전라남도 완도산, 제주도 김녕산, 제주도 서귀포산, 제주도 성산산 바지락과 in vitro 배양된 바지락포자충이 이용되었으며, 대조구로서 전라남도 강진에서 채집된 꼬막, T. granosa을 사용하였다. 실험 결과 Perkinsus특이성 DNA band가 전남 완도산과 제주도 성산산 바지락, in vitro 배양된 바지락 포자충에서 확인되었으나, 대조구였던 꼬막과 제주도 서귀포산, 제주도 김녕산 바지락에서는 나타나지 않았다. 이같은 진단 결과는 FTM과 2M NaOH 진단 결과와 일치하였다. 한편 P. atlanticus에 특이적인 primer에 의해 증폭된 band가 확인됨에 따라 국내산 바지락에서 검출되는 바지락포자충은 P. atlanticus와 동일 종임이 확인되었다. 결론적으로, 본 연구를 통하여 개발된 PCR을 이용한 진단법은 해산 연체동물내 Perkinsus 속 기생충과 P. atlanticus의 감염을 신속하고도 종 특이적으로 진단할 수 있어 수ㆍ출입 수산물의 검역과 바지락 포자충의 생태학적 특성을 규명하는데 효과적으로 이용될 수 있을 것으로 기대된다.

• Nutrition Research and Practice
• /
• 제11권1호
• /
• pp.11-16
• /
• 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.