• Title/Summary/Keyword: shigella

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Acid Tolerance Response of Streptococcus mutans at Anaerobic Condition (Streptococcus mutans의 혐기적 산 내성도 평가)

  • Han, Yang-Keum;Song, Sang-Sun;Lee, In-Soo
    • Journal of dental hygiene science
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    • v.1 no.1
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    • pp.7-11
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    • 2001
  • Streptococcus mutans is one of the primary bacteria that cause dental caries which further result in plaque build up. Acid production resulted from carbohydrate metabolism can threaten survival of the bacteria. However some populations of S. mutans which are exposed to low acidic condition for a period of time would develop resistance and tolerance of cells to acidity that will enhance the chance of survival. Similar acid tolerances has been reported in case of Salmonella enterica serovar typhimurium, E. coli, Shigella flexneri. These acid tolerance responses(ATR) have been evolved in a similar manner as S. mutans. The protein produced in acidic condition has been proven to be important for ATR and confirmed by using chloramphenicol procedure. We hypothesize here that proteins synthesized in response to acid shock and other elements are important for ATR of cells. In this study we have confirmed that S. mutans developed acid tolerance and resistance against anaerobic condition. Mutational DNA analysis responsible for acid tolerance should be additionally required in the future. Since the development of acid tolerance that is essential for the survival of S. mutans and development of dental caries, ATR of S. mutans shoule be farther to prevent dental caries.

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Antibacterial Activities of Cordyceps spp., Mugwort and Pine Needle Extracts (동충하초, 쑥 및 솔잎 추출물의 항균작용)

  • 박찬성;권충정;최미애;박금순;최경호
    • Food Science and Preservation
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    • v.9 no.1
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    • pp.102-108
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    • 2002
  • The purpose of this study was to investigate antibacterial activity of extracts of Cordyceps spp.(Paecilomyces japonica and Cordyceps militaris), mugwort and pine needle. Fruiting body and mycelium of Cordyceps spp., mugwort and pine needle were extracted with water and 70% ethanol. Antibacterial activities of each extracts against 3 kinds of Gram positive (Bacillus subtilis, Listeria monocytogenes and Staphylococcus aureus) and 3 kinds of Gram negative pathogenic bacteria(Escherichia coli O157 : H7, Shigella sonnei and Salmonella typhimurium) were tested. The yields of water and ethanol extracts of fruiting body (39∼58%) were 2.4 ∼4.4 times higher than mycellium(9∼24%) in Cordyceps sup., while those of mugwort and pine needle were less than 9%. Ethanol extract of P. japonica mycelium(JFE) had antibacterial to S. monocytogenes at 1% level and ethanol extract of C. militaris fruiting body (MFE) had antibacterial to S. aureus at 3% level. Ethanol extract of mugwort was antibacterial against L monocytogenes and S. aureus at 1% level. Water extracts of Cordyceps spp.(P. japonica and C. militaris) and mugwort had no antibacterial activity against tested bacterial strains. Water extract of pine needle had antibacterial activity against all bacterial strains except E. coli and ethanol extract had antibacterial activity against all tested bacterial strains at 1% level. Pine needle extracts had the most wide antibacterial spectrum against bacterial strains used for this experiment. Growth inhibiting activities of pine needle extracts were higher in ethanol extract than water extract for most of tested bacteria in tryptic soy broth.

Changes of Indicator Microorganisms and Pathogenic Bacteria in Spinach during Cook-Chill Process (시금치의 cook-chill 가공 중 오염지표균 및 병원성세균의 변화)

  • Kim, Hye-Jung;Park, Jae-Kap;Lee, Dong-Sun;Paik, Hyun-Dong
    • Korean Journal of Food Science and Technology
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    • v.34 no.5
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    • pp.927-930
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    • 2002
  • Spinach minimally processed using cook-chill and sous vide techniques was vacuum-packed in low gas permeable plastic film, pasteurized at $70^{\circ}C$ for 2 min, cooled rapidly at $3^{\circ}C$, and stored at 3 and $10^{\circ}C$. Contents of mesophilic bacteria, psychrophilic bacteria, anaerobic bacteria, spore-forming bacteria, total coliforms, yeast and molds, fecal Streptococcus, and Enterobacteriacea were measared to identify the degree of food contamination. Number of mesophilic bacteria, detected at $2.2{\times}10^8\;cfu/g$ in raw spinish, decreased to about $6.0{\times}10^3\;cfu/g$ after cook-chill process. During the storage at 3 or $10^{\circ}C$, levels of mesophilic, psychrophilic and anaerobic bacteria increased, whereas total coliforms, yeast and molds, fecal Streptococcus, and Enterobacteriacea were not detected. Twelve strains of Aeromonas hydphila, Escherichia coli O157:H7, Plesiomonas shigelloides, Pseudomonas aeruginosa, Salmonella spp., Shigella spp., Yersinia enterocolitica, Bacillus cereus, Campylococcus spp., Clostridium perfringens, Listeria monocytogenes, and Staphylococcus aureus were examined for detecting the presence of pathogenic bacteria in spinach. B. cereus and C. perfringens were isolated from raw, washed, and cook-chilled spinach, whereas A. hydrophila was isolated only from washed spinach. S. aureus was isolated from raw and washed spinach, but not from cook-chilled spinach. Other pathogenic organisms were not detected in raw, washed, and cook-chilled spinach.

Evaluation of Physicochemical Properties and Biological Activities of Steamed and Fermented Deodeok (Codonopsis lanceolata) (증숙 및 발효 더덕의 이화학적 특성 및 생리활성 변화)

  • Jung, Lae-Seung;Yoon, Won-Byung;Park, Sung-Jin;Park, Dong-Sik;Ahn, Ju-Hee
    • Korean Journal of Food Science and Technology
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    • v.44 no.1
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    • pp.135-139
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    • 2012
  • This study was designed to evaluate the physicochemical properties and biological activities of steamed and fermented Codonopsis lanceolata. The treatments included NS-NF (non-steamed and non-fermented), NS-LF (non-steamed and L. rhamnosus fermented), S-NF (steamed and non-fermented), and S-LF (steamed and L. rhamnosus fermented). Total polyphenol amounts of S-NF and S-LF were significantly increased to more than 26 mg GAE/g. The highest DPPH scavenging activities were observed for S-NF and S-LF, showing $EC_{50}$ values of 0.8 and 0.6 mg/mL, respectively. The growths of Staphylococcus aureus, Listeria monocytogenes, Salmonella Typhimurium, and Shigella boydii were effectively inhibited by S-LF (MIC < 9 mg/mL). The NS-LF and S-LF ($EC_{50}$ <6 mg/mL) effectively inhibited ${\alpha}$-Glucosidase and tyrosinase activities compared to NS-NF ($EC_{50}$ <17 mg/mL). The S-LF exhibited the highest acetylcholinesterase (AChE) inhibitory activity ($IC_{50}$ <32 mg/mL). Therefore, the results suggest that the application of the steaming process combined with probiotic fermentation can effectively enhance the biological and pharmacological activities in C. lanceolata.

Probiotic Potential of Pediococcus pentosaceus BCNU 9070 (프로바이오틱 Pediococcus pentosaceus BCNU 9070 균주)

  • Shin, Hwa-Jin;Choi, Hye-Jung;Kim, Dong-Wan;Ahn, Cheol-Soo;Lee, Young-Geun;Jeong, Young-Kee;Joo, Woo-Hong
    • Journal of Life Science
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    • v.22 no.9
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    • pp.1194-1200
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    • 2012
  • Lactic acid bacteria are generally recognized as beneficial probiotic organisms. Recent studies revealed that the potential of probiotic strains was essentially dependent on the bacterial-binding and adhesion capabilities to gut epithelial cells and the hydrophobicity of the cell surface. In this study, we screened some indigenous lactic acid bacteria from Kimchi and selected one lactic acid bacterium as a potential probiotic based on its cell surface hydrophobicity. Analysis of the 16S rRNA gene sequences of probiotic isolates indicated that the selected isolate (BCNU 9070 strain) was a member of Pediococcus pentosaceus. P. pentosaceus BCNU 9070 showed resistance to bile acids and acidic pH. The P. pentosaceus BCNU 9070 strain also inhibited the cell growth of six food-borne pathogens including Listeria monocytogenes and Shigella sonnei. In addition, the P. pentosaceus BCNU 9070 strain expressed bile salt hydrolase activity and showed an ability to assimilate cholesterol in vitro. On the basis of these results, P. pentosaceus BCNU 9070 is considered to have probiotic potential for applications in functional foodstuffs.

Isolation and Characterization of a Paenibacillus incheonensis YK5 with Antimicrobial Activity aginst MRSA (항MRSA 활성을 보이는 Paenibacillus incheonensis YK5의 분리 및 특성)

  • Yoon, Young-Jun;Kim, Hye-Yoong;Lee, Tae-Soo;Kim, Jung-Wan
    • Korean Journal of Microbiology
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    • v.44 no.4
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    • pp.326-332
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    • 2008
  • Various bacteria were isolated from Korean soil samples based on their capability inhibiting the growth of MRSA strains. Among them, strain YK5 with the highest activity was a Gram positive sporulative bacillus with motility. It did not produce indole and no acid was formed from mannitol by the bacterium. The 16S rRNA sequence of the strain showed $95{\sim}98%$ homology with those of Paenibacillus spp.. The bacterial isolate shared the highest homology with that of P. elgii (98%), but was named as Paenibacillus incheonensis YK5 due to differences in physiological properties. Butanol extract of the P. incheonensis YK5 culture grown in SST medium at $37^{\circ}C$ for 96 hr showed a broad antimicrobial activity against Gram-positive (MRSA and Streptococcus pneumoniae) and negative (Pseudomonas aeruginosa, Salmonella spp., Shigella spp., Escherichia coli, Klebsiella pneumoniae) pathogenic bacteria and fungi (Cryptococcus neoformans and Trichophyton). The antimicrobial activity in the crude extract was stable in a broad range of temperature and pH, $20{\sim}100^{\circ}C$ and $3.0{\sim}6.0$, respectively. Therefore, the antimicrobial activity of P. incheonesis YK5 had potential as a novel antibiotics for pathogens including MRSA.

Prevalence of Multi-drug Resistant Bacteria Belonging to Gram Negative Enterobacteriaceae Isolated from a Domestic Stream (국내 하천에서 분리된 그람 음성 Enterobacteriacaea의 항생제 다제내성)

  • Jang, Yejin;Song, Ki-Bong;Chung, In-Young;Kim, Hyuk;Seok, Kwang-Seol;Go, Eun Byeul;Kim, Byeori;Yoo, Yong-Jae;Rhee, Ok-Jae;Chae, Jong-Chan
    • Microbiology and Biotechnology Letters
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    • v.43 no.4
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    • pp.396-400
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    • 2015
  • Enterobacteriaceae is one of the major families responsible for public health threats. Due to the emergence of pathogens with antibiotic resistance, great concern has been raised regarding the prevalence of antibiotic resistant bacteria in natural environments. Therefore, the diversity of Gram negative Enterobacteriaceae was investigated in water samples collected from five streams in Korea using the cultivation method. Profiling of multi-drug resistance was conducted with isolates via disk diffusion assay. The results indicated that the Gram negative Enterobacteriaceae consisted of the following genus; Citrobacter, Enterobacter, Escherichia, Klebsiella, Kluyvera, Pantoea, Plesiomonas, Raoultella, Shigella and Enterobacter. These latter strains represented 49% of identified isolates. In addition, 78.3% of the identified genus exhibited resistance against more than seven out of thirteen tested antibiotics, suggesting a high prevalence of multi-drug resistant bacteria in natural environments.

Studies on the Antibacterial Activity of Poria cocos (복령의 항균력(抗菌力)에 관한 연구(硏究))

  • Lee, Kook-Sung;Lee, Min-Woong;Lee, Ji-Yul
    • The Korean Journal of Mycology
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    • v.10 no.1
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    • pp.27-31
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    • 1982
  • The antibacterial activity of Poria cocos against the human pathogenic bacteria and general bacteria was observed. The results obtained were as follows; 1. There wasn't any anti­bacterial activity at the Poria cocos powders, pieces and its extracts in every different kinds and places of origin. 2. Hyphae of Poria cocos in every different kinds and places of origin had the antibacterial activity against four Gram positive bacteria, i.e., Staphylococcus aureus, S. epidermidis, Bacillus subtilis and Streptococcus faecalis, on the other hand, hadn't the antibacterial activity against six Gram negative bacteria, Salmonella typhi, Shigella dysenteriae, Pseudomonas aeruginosa, Escherichia coli, Proteus vulgaria and Klebsiella pneumoniae. 3. The average inhibitory zone was 13.6mm for S. aureus, 14.7mm for S. epidermidis, 12.7mm for B. subtilis, and 13.2mm for S. faecalis at the concentration of $335{\mu}g$ of hyphae of Poria cocos.

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Profiling and Priority Selection of Foodborne Pathogens in Fresh Produce (국내 신선 농산물 생물학적 위해요소 우선순위 설정)

  • Lee, Chaeyoon;Sung, Dongeun;Oh, Sangsuk
    • Journal of Food Hygiene and Safety
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    • v.27 no.4
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    • pp.356-365
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    • 2012
  • There have been growing concerns among people about food safety due to insufficient information on foodborne pathogens. In this study, we developed a risk priority of 15 foodborne pathogens. For the priority determination we collected risk profile criteria information from CODEX Alimentarius Commission and developed countries. The basis for criteria we selected from information of surveillance were frequency and severity of disease, frequency of consumption and probability of cross-contamination. We also considered foodborne pathogens which have been managed in developed countries though those pathogens are not currently managed appropriately in Korea. Priorities were divided into three groups following these consideration. The first priority group includes Norovirus, pathogenic E. coli, Salmonella spp, Clostridium botulinum and Listeria monocytogenes. The second priority group includes Vibrio parahaemolyticus, Stapylococcus aureus, Campylobacter jejuni and Bacillus cereus, and the third priority group includes Clostridium perfringens, Yersinia enterocolitica, Shigella spp, Cronobacter sakazakii and Hepatitis A virus. Our results could be applied to prevent foodborne illness from fresh produce.

Improvement effect of cooked soybeans on HFD-deteriorated large intestinal health in rat model (쥐 모델에서 고지방사료로 악화된 대장 건강에 대한 콩의 개선 효과)

  • Choi, Jae Ho;Shin, Taekyun;Ryu, Myeong Seon;Yang, Hee-Jong;Jeong, Do-Youn;Unno, Tatsuya
    • Journal of Applied Biological Chemistry
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    • v.64 no.4
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    • pp.383-389
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    • 2021
  • Obesity is associated with impaired intestinal epithelial barrier function, which contribute to host systemic inflammation and metabolic dysfunction. Korean traditional foods, fiber-rich bean products, have been various biological activities in anti-inflammatory responses, but has not reported the large intestinal health. In this study, we investigated the intestinal health promoting effect of cooked soybeans (CSB) on high fat diet (HFD)-induced obesity model. SD rat were fed either a HFD or HFD supplemented with 10.6% CSB (HFD+CSB) for animal experimental period. CSB treatment significantly decreased the HFD-induced weights of body and fat. Also, CSB treatment improved HFD-reduced tight junction components (ZO-1, Claudin-1, and Occludin-1) mRNA expression in large intestine tissue. Additionally, histopathological evaluation showed that CSB treatment attenuated the HFD-increased inflammatory cells infiltration and epithelial damages in large intestine tissue. At the genus level, effects of CSB supplement not yet clear, while dietary effects showed differential abundance of several genera including Lactobacillus, Duncaniella, and Alloprevotella. NMDS analysis showed significant microbial shifts by HFD, while CSB did not shift gut microbiota. CSB increased the abundance of the genera Anaerotignum, Enterococcus, Clostridium sensu stricto, and Escherichia/Shigella by linear discriminant analysis effect size analysis, while reduced the abundance of Longicatena and Ligilactobacillus. These findings indicate that CSB supplement improves HFD-deteriorated large intestinal health by the amelioration of tight junction component, while CSB did not shift gut microbiotas.