• Title/Summary/Keyword: bacterial numbers

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Effect of R. leguminisarum Pre-incubated with Inducers, Naringenin and Methyl-jasmonate, on Nitrogen Fixation and the Growth of Pea at Different Salinity Levels

  • Lee, Kyung-Dong
    • Korean Journal of Environmental Agriculture
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    • v.27 no.4
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    • pp.362-367
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    • 2008
  • The legume-rhizobia symbiosis is an important source of plant growth and nitrogen fixation for many agricultural systems. This study was conducted to investigate the effects of salinity stress on nitrogen fixation and growth of pea (Pisum sativum L.), which has antimutagenic activities against chemical mutagen, inoculated with R. leguminosarum bv. viciae cultured with additional plant-to-rhizobia signal compounds, naringenin (NA,15 uM), methyl-jasmonate (MJ, 50 uM) or both, under greenhouse conditions. Three salinity levels (0.6, 3.0 and $6.0\;dS\;m^{-1}$) were imposed at 3 days after transplanting and maintained through daily irrigations. Addition of signal compounds under non-stress and stress conditions increased dry weight, nodule numbers, leaf area and leaf greenness. The inducers increased photosynthetic rate under non-stress and stress conditions, by approximately 5-20% when compared to that of the non-induced control treatment. Under stress conditions, proline content was less in plants treated with plant-to-bacteria signals than the control, but phenol content was significantly increased, compared to that of the control. The study suggested that pre-incubation of bacterial cells with plant-to-bacteria signals could enhance pea growth, photosynthesis, nitrogen fixation and biomass under salinity stress conditions.

Microbial Evaluation of Commercially Packed Kimchi Products

  • Kwon, Eun-A;Kim, Myung-Hee
    • Food Science and Biotechnology
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    • v.16 no.4
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    • pp.615-620
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    • 2007
  • Commercially packed kimchi products from 6 different manufacturers, which are exported overseas as well as sold domestically, were analyzed to determine their microorganism distributions and presence of pathogenic bacteria. All samples showed decreasing pH levels (from 5.7-6.2 to 3.9-4.3) and increasing titratable acidities (from 0.3-0.4 to 0.8-1.2%) during 15 days of storage at $4^{\circ}C$. Total bacterial counts ranged from $2.1{\times}10^5-1.9{\times}10^6\;CFU/mL$ in the initial kimchi samples, and then increased to $1.1{\times}10^8-1.8{\times}10^9\;CFU/mL$. The coliform numbers decreased from approximately $2.5{\times}10^2-1.7{\times}10^4\;CFU/mL$ to zero. Major foodborne pathogens such as Salmonella spp., Staphylococcus aureus, Escherichia coli O157:H7, Listeria monocytogenes, Bacillus cereus, Yersinia enterocolitica, and Shigella spp. were not detected in any of the samples. However, 2 out of the 6 samples carried E. coli, emphasizing the need for improved hygiene practice. Interestingly, Hafnia alvei, belonging to the Enterobacteriaceae family, was isolated in all of the samples. Further study is needed on this newly reported bacterium in kimchi.

Pulmonary Coccidioidomycosis Diagnosed in an Immigrant (외국에서 감염된 콕시디오이데스 진균증)

  • Shin, Jae-Seung;Lee, In-Sung;Shin, Chol;Kim, Ae-Ree
    • Tuberculosis and Respiratory Diseases
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    • v.51 no.5
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    • pp.448-452
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    • 2001
  • Coccidioidomycosis is a common infectious disease in southwestern North America, which is caused by the soil fungus, Coccidioides immitis. Due to the mobility of the modem population, increasing numbers of cases are being diagnosed outside the endemic areas. Moreover, diagnosis in non-endenmic areas may be delayed or confused due to its rarity. Here we report a case of pulmonary coccidioidomycosis in an immigrant. The patient presented with unexplained pulmonary symptoms. A history of recent travel to or immigration from an endemic area may suggest coccidioidomycosis. In addition an early tissue biopsy is helpful in establishing this diagnosis.

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Immunohistochemical identification of listeria monocytogenes antigen in tissue sections of experimentally infected rats after pretreatment with dexamethasone (Dexamethasone 전처리후 Listeria monocytogenes를 인공감염시킨 랫드의 조직절편내 균체항원 동정)

  • Sur, Jung-hyang;Kim, Soon-bok
    • Korean Journal of Veterinary Research
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    • v.32 no.1
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    • pp.91-98
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    • 1992
  • Listeria monocytogenes antigens were detected with the avidinbiotinperoxidase complex(ABPC) method in formalin-fixed, paraffin-embedded tissues from experimentally infected rats, mice and guinea pigs. The anti-Lirteria monocytogenes serum used as first antibody was prepared by immunizing rabbits with Listeria monocytogenes serotype 1/2a. Rats, mice and guinea pigs that had been given inoculation of L monocytogenes(serotype 4b, Scott A strain) via intraperitoneally allotted to 3 groups. Rats were pretreated with the dexamethasone(DM-rats) for 7 consecutive days, mice and guinea pigs were inoculated intraperitoneally with L. monocytogenes At necropsy white necrotic foci of the liver, spleen and kidney were seen in mice and DM-rats, whereas not in guinea pigs. Organisms stained by the ABPC method were identified as pleomorphic dark brown staining structures in the livers, spleens and kidneys of mice and DM-rats. They were present in high numbers in center and peripherial regions of necrobiotic and necrotic foci of the liver and spleen as well as in glomerulus of the renal cortex. and liable tool for confirmative diagnosis of these bacterial diseases.

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Isolation and Characterization of Ultra-Violet and Gamma-radiation Resistant Bacteria from Natural Habitats (자연 생태계로 부터 자외선 및 방사선 내성 박테리아의 분리 및 특성 연구)

  • 이영남;이인정
    • Korean Journal of Microbiology
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    • v.27 no.3
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    • pp.297-303
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    • 1989
  • Attempts to isolate the naturally occurring ultra-violet resistant bacteria from environmental sources were made. The isolates, designated No.29, 100, and 107, among numbers of bacterial isolates revealed a remarkable resistance to UV ray, whose degree of resistance in dose/response kinetics was comparable to that of an endospore-former, Bacillus subtilis. In a range of 100-300 $Jm^{-2}$/min of UV irradiation, the isolates exhibited 500-1000 fold resistance compated with E. coli. The isolated appeared to possiss cell-bound pigment of organge or crimson-red. The isolate 29 is spherical in pairs or tetrads, whereas the isolates 100 and 107 are rod. All are Gram-gositive bacteria and seemed to be non-endospore-bearer. A number of biochemical studies pursued on the isolates suggested that they are quite different to each other. Electron microscopic examination and the physiological characters of the isolate 29 suggested that this UV resistant spherical bacterium might be one species of Deinococcus, probably Deinococus radiophilus. Since there is no documents on UV resistant, Gram-positive, non-sporeformer bacillus so far, the isolates 100 and 107 might be turned out as new kinds of UV resistant bacteria occurring in nature by further investigation.

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Enhanced and Balanced Microalgal Wastewater Treatment (COD, N, and P) by Interval Inoculation of Activated Sludge

  • Lee, Sang-Ah;Lee, Nakyeong;Oh, Hee-Mock;Ahn, Chi-Yong
    • Journal of Microbiology and Biotechnology
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    • v.29 no.9
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    • pp.1434-1443
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    • 2019
  • Although chemical oxygen demand (COD) is an important issue for wastewater treatment, COD reduction with microalgae has been less studied compared to nitrogen or phosphorus removal. COD removal is not efficient in conventional wastewater treatment using microalgae, because the algae release organic compounds, thereby finally increasing the COD level. This study focused on enhancing COD removal and meeting the effluent standard for discharge by optimizing sludge inoculation timing, which was an important factor in forming a desirable algae/bacteria consortium for more efficient COD removal and higher biomass productivity. Activated sludge has been added to reduce COD in many studies, but its inoculation was done at the start of cultivation. However, when the sludge was added after 3 days of cultivation, at which point the COD concentration started to increase again, the algal growth and biomass productivity were higher than those of the initial sludge inoculation and control (without sludge). Algal and bacterial cell numbers measured by qPCR were also higher with sludge inoculation at 3 days later. In a semi-continuous cultivation system, a hydraulic retention time of 5 days with sludge inoculation resulted in the highest biomass productivity and N/P removal. This study achieved a further improved COD removal than the conventional microalgal wastewater treatment, by introducing bacteria in activated sludge at optimized timing.

Effect of Marination with Black Currant Juice on the Formation of Biogenic Amines in Pork Belly during Refrigerated Storage

  • Cho, Jinwoo;Kim, Hye-Jin;Kwon, Ji-Seon;Kim, Hee-Jin;Jang, Aera
    • Food Science of Animal Resources
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    • v.41 no.5
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    • pp.763-778
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    • 2021
  • The effect of marination with black currant juice (BCJ) was investigated for their effects on meat quality and content of biogenic amines (BAs) [putrescine (PUT), cadaverine (CAD), histamine (HIM), tyramine (TYM), and spermidine (SPD)] in pork belly during storage at 9℃. BCJ was shown to have antibacterial activities against Escherichia coli and Pseudomonas aeruginosa. Additionally, the pH of pork belly marinated with BCJ (PBB) was significantly lower than that of raw pork belly (RPB) during storage. No significant difference in microorganisms between RPB and PBB was observed at day 0 of storage. However, at days 5 and 10 of storage, volatile basic nitrogen (VBN) was significantly decreased in PBB compared to RPB, and PBB also demonstrated significantly lower numbers of bacteria associated with spoilage (Enterobacteriaceae and Pseudomonas spp.) at these time-points. PBB was also associated with significantly reduced formation of BAs (PUT, CAD, TYM, and total BAs) compared to RPB at days 5 and 10 of storage. These results indicated that BCJ can be regarded as a natural additive for improving meat quality by preventing increased pH, VBN, bacterial spoilage, and inhibiting BAs formation during refrigerated storage.

The change of PHP index and copy numbers of periodontal bacteria in patients with professional periodontal prevention management (PHP INDEX에 따른 전문가 치주예방관리 환자의 치주질환 원인균 copy 수 변화)

  • Mi-Young, Jin;Byeng-Chul, Yu
    • Journal of Korean Dental Hygiene Science
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    • v.5 no.2
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    • pp.155-164
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    • 2022
  • Background: By regulating the factors that contribute to oral diseases in a healthy way, oral health can be maintained and prevented. Methods: The general characteristics, PHP index, oral health behavior, and clinical periodontal index of each group were calculated by frequency analysis, and a cross-analysis (χ2 test) was conducted to assess the homogeneity of the general characteristics, oral health behavior, and clinical periodontal index of the study subjects. An Oral bacteriological examination was performed by gargling with saliva. Results: The expert periodontal prevention group showed a decrease in the copy number of periodontal disease causative bacteria, and A. actinomycetemcomitans, P. gingivalis, T. forsythus, andT. denticolashowed a significant difference before and after treatment (p=0.021). In the periodontal treatment group, A. actinomycetemcomitans, P. gingivalis, T. forsythus, andT. denticolaall showed a decrease in copy number, but there was no significant difference. Conclusions: This study showed professional periodontal prevention management had some effect on periodontal bacterial reduction.

Effect of Gamijipaesan Extracts against Mastitis Induced by Staphylococcus aureus Infection in a Rat Model through Anti-inflammatory and Antibacterial Effects (가미지패산(加味芷貝散)의 포도상구균 감염 유방염에 대한 항균활성 및 항염 효과)

  • Kwon, Ji-Myung;Kim, Dong-Chul
    • The Journal of Korean Obstetrics and Gynecology
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    • v.26 no.1
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    • pp.1-24
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    • 2013
  • Objectives: The object of this study was to observe the protective effect of Gamijipaesan aqueous extracts(GJS), which has been traditionally used in Korean medicine in obstetrics & gynecological fields as anti-infectious and anti-inflammatory agents, against mastitis induced by Staphylococcus aureus infection in a rat model through antibacterial, antiinflammatory, immunomodulatory, and anti-oxidant effects. Methods: Antibacterial activities of GJS against S. aureus were detected using standard agar microdilution methods, with the effects on the bacterial invasion and intracellular killing of individual test materials in human mammary gland carcinoma cell(MCF-7) and murine macrophages(Raw 264.7) at MIC1/2, MIC and MIC2 concentration levels. In addition, the effects on the cell viability, nitric oxide(NO), tumor necrosis factor(TNF)-${\alpha}$ and interleukin (IL)-6 productions of LPS activated Raw 264.7 cells. The changes on the mammary tissue viable bacterial numbers, myeloperoxidae(MPO), inducible nitric oxide synthetase(iNOS), TNF-${\alpha}$ and IL-6 contents were observed in the S. aureus in vivo intramammary infectious rat model. The anti-bacterial and anti-inflammatory effects were compared with ciprofloxacin and piroxicam, respectively in the present study. Results: MIC of GJS and ciprofloxacin against S. aureus were detected as $0.860{\pm}0.428$ (0.391-1.563) mg/ml and $0.371{\pm}0.262$(0.098-0.782) ${\mu}g/ml$, respectively. In addition, GJS and ciprofloxacin were also showed marked dosage-dependent inhibition of the both bacterial invasion and intracellular killing assays using MCF-7 and Raw 264.7 cells at MIC1/2, MIC and $MIC{\times}2$ concentrations, respectively. $ED_{50}$ against LPS-induced cell viabilities and NO, TNF-${\alpha}$ and IL-6 releases of GJS were detected as 0.72, 0.04, 0.08 and 0.11 mg/ml, and as 19.04, 4.18, 5.37 and 4.27 ${\mu}g/ml$ in piroxicam, respectively. 250 and 500 mg/kg of GJS also inhibit the intramammary bacterial growth, MPO, iNOS, TNF-${\alpha}$ and IL-6 contents in S. aureus in vivo intramammary infected rats, respectively. GJS 500 mg/kg showed quite similar antibacterial and anti-infectious effects as compared with ciprofloxacin 40 mg/kg and also showed similar anti-inflammatory effects as piroxicam 10 mg/kg, in S. aureus in vivo intramammary infectious models. Conclusions: The results obtained in this study suggest that over 250 mg/kg of GJS showed favorable anti-infectious effects against S. aureus infection in a rat model through their antibacterial, anti-inflammatory, immunomodulatory and anti-oxidant effects and therefore expected that GJS can be used as alternative therapies, having both anti-inflammatory and anti-infectious activities. However, more detail mechanism studies should be conducted in future with the efficacy tests of individual herbal composition of GJS and the screening of the biological active compounds in individual herbs. In the present study, GJS 500 mg/kg showed quite similar anti-infectious effects were detected as compared with ciprofloxacin 40 mg/kg treated rats, and also GJS shows quite similar anti-inflammatory effects as compared with piroxicam 10 mg/kg in S. aureus in vivo intramammary infectious rats, but ciprofloxacin did not showed any anti-inflammatory effects, and piroxicam did not showed anti-infectious effects in this study.

Bactericidal Efficacy of Fumagari OPP®, Fumigant Against Escherichia coli and Salmonella typhimurium (훈증소독제, Fumagari OPP®의 Escherichia coli와 Salmonella typhimurium에 대한 살균효과)

  • Park, Eun-Kee;Kim, Yongpal;Yu, Eun-Ah;Yoo, Chang-Yeol;Choi, Hyunju;Kim, Suk;Lee, Hu-Jang
    • Journal of Food Hygiene and Safety
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    • v.28 no.3
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    • pp.234-240
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    • 2013
  • This test was performed to evaluate the bactericidal efficacy of Fumagari OPP$^{(R)}$, fumigation disinfectant, containing 20% ortho-phenylphenol against Escherichia coli (E. coli) and Salmonella typhimurium (S. typhimurium). In preliminary tests, both E. coli and S. typhimurium working culture suspension number (N value) was $4.0{\times}10^8$ CFU/mL. And all of the colony numbers on the carriers exposed the fumigant (n1, n2, n3) were higher than 0.5N1 (the number of bacterial test suspentions by pour plate method), 0.5N2 (the number of bacterial test suspentions by filter membrane method) and 0.5N1, respectively. In addition, the mean number of bacteria recovered on the control-carriers (T value) was $3.4{\times}10^6$ CFU/mL. In the bactericidal effect of the fumigant, the reduction number of S. typhimurium and E. coli (d value) was 5.26 and 5.64 logCFU/mL, respectively. According to the French standard for the fumigant, the d value for the effective bactericidal fumigant should be over than 5 logCFU/mL. With the results of this study, Fumagari OPP$^{(R)}$ has an effective bactericidal activity, then the fumigant can be applied to disinfect food materials and kitchen appliances contaminated with pathogenic bacteria.