• Restorative Dentistry and Endodontics
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• v.43 no.3
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• pp.28.1-28.16
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• 2018

This study investigated the latest findings and notions regarding 'triple antibiotic paste' (TAP) and its applications in dentistry, particularly endodontics. TAP is a combination of 3 antibiotics, ciprofloxacin, metronidazole, and minocycline. Despite the problems and pitfalls research pertaining to this paste has unveiled, it has been vastly used in endodontic treatments. The paste's applications vary, from vital pulp therapy to the recently introduced regeneration and revascularisation protocol. Studies have shown that the paste can eliminate the root canal microorganisms and prepare an appropriate matrix for further treatments. This combination is able to remove diverse groups of obligate and facultative gram-positive and gram-negative bacteria, providing an environment for healing. In regeneration protocol cases, this allows the development, disinfection, and possible sterilization of the root canal system, so that new tissue can infiltrate and grow into the radicular area. Moreover, TAP is capable of creating a discipline in which other wanted and needed treatments can be successfully performed. In conclusion, TAP, as an antibacterial intracanal medication, has diverse uses. Nevertheless, despite its positive effects, the paste has shown drawbacks. Further research concerning the combined paste and other intracanal medications to control microbiota is a must.

• YAKHAK HOEJI
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• v.40 no.1
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• pp.95-101
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• 1996

The in vitro antibacterial activities of LB10522, a new catechol-substituted cephalosporin, were compared with those of cefpirome, ceftazidime, ceftriaxone, and cefoperaz one against clinical isolates and laboratory standard anaerobes. LB10522 had broad spectrum antibacterial activities against both gram-positive and gram-negative microorganisms. It was most active against gram-positve bacteria among the reference cephalosporins tested. Against gram-negative strains such as the family Enterobacteriaceae, LB10522 showed an activity comparable to that of cefpirome. But LB10522 was more potent than ceftazidime, ceftriaxone and cefoperazone. In particular, Pseudomonas aeruginosa was highly susceptible to LB10522, which was 32-fold and 64-fold more active than ceftazidime and cefpirome, respectively. Against anaerobic strains, the activity of LB10522 was similar to those of reference compounds. LB10522 exhibited potent therapeutic activities against experimental local infections in mice. The therapeutic effect of LB10522 against urinary tract infection (UTI) caused by P. aeruginosa 1912E in mice was superior to that of cefpirome. Against experimental respiratory tract infection (RTI) caused by K. pneumoniae DT-S in mice, LB10522 was as effective as cefpirome. The in vivo efficacy of LB10522 was correlated well with its in vitro activity.

• Korean Journal of Microbiology
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• v.46 no.4
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• pp.334-340
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• 2010

It is well known that smoking as well as drinking is a factor of stomatopathy, however there are few investigations about comparison of oral flora between smokers and non-smokers. In this study, we isolated the oral flora of 30 smokers and 30 non-smokers and cultured them on blood agar plates. The isolated pathogenic microorganisms were tested for antibiotic susceptibility and resistance using the Kirby-Bauer antibiotic testing method. Each colony was stained using the Gram staining method and was identified by an automatic identifier, known as the VITEK system. We isolated 41 colonies from smokers' oral cavity, and they were sorted as 63% of Gram-positive cocci, 29% of Gram-negative cocci, 3% of Gram-positive bacilli, and 5% of Gram-negative bacilli by gram staining, whereas 38 colonies were isolated from non-smoters' oral cavity, and their proportions were 55% of Gram-positive cocci, 26% of Gram-negative cocci, 3% of Gram-positive bacilli, and 16% of Gram-negative bacilli. The VITEK system revealed specific distribution of bacteria species that Streptococcus mutans (6/41), Gemella morillorum (6/41), Streptococcus oralis (2/41), Streptococcus pneumoniae (1/41), Staphylococcus aureus (3/41), Streptococcus anginosus (1/41), Streptococcus intermedius (1/41), Streptococcus uberis (1/41), and Streptococcus sanguinis (1/41) in smokers oral cavity whereas Streptococcus sanguinis (8/38), Staphylococcus aureus (1/38), Staphylococcus auricularis (1/38), Streptococcus uberis (1/38), Streptococcus intermedius (1/38), Streptococcus mutans (1/38), and Streptococcus oralis (1/38) in those of non-smokers'. Three cases of Staphylococcus aureus from smokers produced Beta-lactamase and were identified methicillin-resistance Staphylococcus aureus (MRSA). However one case of Staphylococcus aureus from non-smoker did not produce Beta-lactamase and was sensitive to methicillin. In conclusion, the distribution of oral flora was different between smokers' and non-smokers' oral cavity, especially Gemella morillorum and MRSA were predominantly found in smoker's oral cavity. These results are useful in the treatment and prevention of patients with stomatopathy caused by smoking.

• Journal of Korean Ophthalmic Optics Society
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• v.2 no.1
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• pp.85-90
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• 1997

The cornea and conjunctiva of the human eye are exposed to external environment and thus are damageable. If the damaged part is infected with some pathogenic microorganisms. serious visual loss may be occured by inflammation. Keratitis or conjunctivitis does not always occur if the eyes are routinely exposed to pathogenic factors because lysozyme in human tears has antimicrobial activity against the microorganisms. 10 this study we have selected 5 strains causing keratitis and/or conjunctivitis. and cultured them in the optimum media. And then we have estimated the growth inhibition of the strains with the addition of various concentration of lysozyme to media to investigate the antimicrobial activity of lysozyme. The results are as follows. The growth of the strains were decreased according to the increase of lysozyme concentration. The growth of Pseudomonas. Neisseria. Klebsiella and Staphylococcus were inhibited 43%, 41%, 35% and 22% respectively by 1 mM concentration of lysozyme. The susceptibility of the gram-negative bacteria to lysozyme is 1.5~2 times higher than the Staphylococcus which is gram-positive bacteria in 1 mM concentration of lysozyme. But lysozyme inhibited the growth of Fusarium which is fungi slightly.

• Food Science and Preservation
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• v.14 no.1
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• pp.87-93
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• 2007

This study investigated the antimicrobial effect of germinated acorn pollen solution on harmful food-borne microorganisms. The antimicrobial activity when 8% (w/v) acorn pollen in 10% (w/v) sugar solution was extracted at $30^{\circ}C$ for 4 days. The minimal inhibitory concentration of this germinated acorn pollen solution was $40\;{\mu}L/mL$ for Gram-positive bacteria and $30\;{\mu}L/mL$ for Gram-negative bacteria. Acetic and lactic acids were present at high levels in germinated acom pollen solution. As pollen germination releases heat, the antimicrobial activities are heat-stable. The activities are tolerant of low pH. In summary, acorn pollen germination solution showed active antibiosis and should be developed as a natural preservative material.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.74-79
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• 1995

Autoclaved juices of common vegetables including cabbage were growth inhibitory to various microorganisms. Sensitivity of microorganisms to antimicrobial action of autoclaved vegetable juices was different depending on microbial strains. Lactic acid bacteria and Gram negative bacteria were less sensitive while non-lactic Gram positive bacteria and yeasts were very much sensitive to antimicrobial action of autoclaved cabbage juice(ACJ). Staphylococcus aureus and Candida utilis whose growth were completely inhibited in ACJ could grow in ACJ diluted with distilled water. This suggests that microorganisms were not able to grow in ACJ because of growth inhibitory compounds produced during heating but not because of the lack of nutrients. Cabbage juice heated at $100^{\circ}C$ for up to 30 min was not inhibitory while that heated at $121^{\circ}C$ for 5 min was. Heating temperature was an important parameter in generating growth inhibitory compound in heated cabbage juice.

• Food Science and Preservation
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• v.6 no.2
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• pp.239-244
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• 1999

Antimicrobial activity to the extracts of Perilla frutescens Briton var. acuta Kudo was investigated against various foodborne pathogenes or food poisioning microorganisms(Aspergillus flavus KCTC 6143 and KCTC 6961, Aspergillus niger ATCC 4695, Listeria monocytogenes ATCC 15313, Staphylococcus aureus 196E ATCC 13565, Escherichia coli O157:H7 ATCC 43895, Salmonella typhimurium ATCC 13311 and Yersinia enterocolitica). The ethanol extract of Perilla frutescens Briton var. acuta Kudo was very stable over heat at $121^{\circ}C$ for 15 min. In concentration of $1000\mu\textrm{g}$/mL into culture broth(TSB), the ethanol extract of Perilla frutescens Briton var. acuta Kudo showed the strongest antimicrobial activities against Listeria monocytogenes, followed by Staphylococcus aureus 196E, Salmonella typhimurium. Gram negative bacteria(Escherichia coli O157:H7, Salmonella 쇼phimurium, Yersinia enterocolitica) were less sensitive than Cram positive bacteria but the growth of Escherichia coli O157:H7 and Yersinia exterocolitica were inhibited with increasing concentrations of the extract in culture broth.

• Food Science of Animal Resources
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• v.43 no.3
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• pp.402-411
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• 2023

This study was conducted to investigate the bactericidal effect of nisin (Nisin) only, atmospheric pressure plasma (APP) only, and a combination of APP and nisin (APP+Nisin)(APP+Nisin) on beef jerky and sliced ham inoculated with Escherichia coli O157:H7, gram-negative bacteria. The bactericidal effect against E. coli O157:H7 and Listeria monocytogenes was confirmed using a nisin solution at a concentration of 0-100 ppm, and APP+Nisin was tested on beef jerky and sliced ham using 100 ppm nisin. Beef jerky and sliced ham were treated with APP for 5 min and 9 min, respectively. In the bacterial solution, 100 ppm nisin out of 0-100 ppm nisin exhibited the highest bactericidal activity against L. monocytogenes (gram-positive bacteria; p<0.05); however, it did not exhibit bactericidal effects against E. coli O157:H7 (gram-negative bacteria). The APP+Nisin APP+Nisin exhibited a 100% reduction rate in both E. coli O157:H7 and L. monocytogenes compared to the control group, and was more effective than the Nisin. The APP+Nisin decreased the number of colonies formed by 0.80 and 1.96 Log CFU/g for beef jerky and sliced ham, respectively, compared to the control, and exhibited a higher bactericidal effect compared to the Nisin (p<0.05). These results demonstrate the synergistic bactericidal effect of APP and nisin, providing a possible method to improve the limitations of nisin against gram-negative bacteria. In addition, this technology has the potential to be applied to various meats and meat products to control surface microorganisms.

• Animal Bioscience
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• v.37 no.2_spc
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• pp.337-345
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• 2024

Ruminants possess a specialized four-compartment forestomach, consisting of the reticulum, rumen, omasum, and abomasum. The rumen, the primary fermentative chamber, harbours a dynamic ecosystem comprising bacteria, protozoa, fungi, archaea, and bacteriophages. These microorganisms engage in diverse ecological interactions within the rumen microbiome, primarily benefiting the host animal by deriving energy from plant material breakdown. These interactions encompass symbiosis, such as mutualism and commensalism, as well as parasitism, predation, and competition. These ecological interactions are dependent on many factors, including the production of diverse molecules, such as those involved in quorum sensing (QS). QS is a density-dependent signalling mechanism involving the release of autoinducer (AIs) compounds, when cell density increases AIs bind to receptors causing the altered expression of certain genes. These AIs are classified as mainly being N-acyl-homoserine lactones (AHL; commonly used by Gram-negative bacteria) or autoinducer-2 based systems (AI-2; used by Gram-positive and Gram-negative bacteria); although other less common AI systems exist. Most of our understanding of QS at a gene-level comes from pure culture in vitro studies using bacterial pathogens, with much being unknown on a commensal bacterial and ecosystem level, especially in the context of the rumen microbiome. A small number of studies have explored QS in the rumen using 'omic' technologies, revealing a prevalence of AI-2 QS systems among rumen bacteria. Nevertheless, the implications of these signalling systems on gene regulation, rumen ecology, and ruminant characteristics are largely uncharted territory. Metatranscriptome data tracking the colonization of perennial ryegrass by rumen microbes suggest that these chemicals may influence transitions in bacterial diversity during colonization. The likelihood of undiscovered chemicals within the rumen microbial arsenal is high, with the identified chemicals representing only the tip of the iceberg. A comprehensive grasp of rumen microbial chemical signalling is crucial for addressing the challenges of food security and climate targets.

• Journal of Aquaculture
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• v.14 no.3
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• pp.157-163
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• 2001

The antibacterial effect of fish diet soaked in the extract of Salvia miltiorriza was tested to determine its levels of antibacterial activity, minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC). The extract showed strong activity against gram positive bacteria, but was weak against gram negative bacteria. Concentration levels of 13.4~40.3 and 67.2~403.0 $\mu\textrm{g}$/ml were determined as the MIC and MBC, respectively. However, levels above 403.0 $\mu\textrm{g}$/ml was neither bacteriostatic nor bactericidal against Edwardsiella tarta, a gram negative strain. The fish diet, soaked in the extract of Salvia miltiorriza, inhibited the growth of all strains of Streptococcus genus and Vibrio anguillarum. The relationship formula between weight of fish diet and Salvia miltiorriza extract absorbed into the fish diet was Y＝2.4953X＋3.3276 ($R^2$= 0.9999). The antibacterial activity of the fish diet, soaked in the extract, was stable from 10 to 35$^{\circ}C$ during the storage period of 28 days.