• Microbiology and Biotechnology Letters
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• v.46 no.4
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• pp.346-359
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• 2018

Xanthomonas oryzae, a bacterial pathogen causing leaf blight disease (BLB) in rice, can cause widespread disease and has caused epidemics globally, resulting in severe crop losses of 50% in Asia. The pathogen is seed-borne and is transmitted through seeds. Thus, control of BLB requires the elimination of the pathogen from seeds. Concern about environment-friendly organic production has spurred improvements in a variety of biological disease control methods, including the use of bacteriophages, against bacterial plant pathogens. The present study explored the potential of bacteriophages isolated from diseased plant leaves and soil samples in killing the bacterial pathogen in rice seeds. Eight different phages were isolated and evaluated for their bacteriolytic activity against different pathogenic X. oryzae strains. Of these, a phage designated ${\varphi}XOF4$ killed all the pathogenic X. oryzae strains and showed the broadest host range. Transmission electron microscopy of ${\varphi}XOF4$ revealed it to be a tailed phage with an icosahedral head. The virus was assigned to the family Siphoviridae, order Caudovirales. Seedlings raised from the seeds treated with $1{\times}10^8pfu/ml$ of ${\varphi}XOF4$ phage displayed reduced incidence of BLB disease and complete bacterial growth inhibition. The findings indicate the potential of the ${\varphi}XOF4$ phage as a potential biological control agent against BLB disease in rice.

• The Korea Journal of Herbology
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• v.27 no.2
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• pp.43-46
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• 2012

Objectives : Sanguisorbae Radix(SO) is a plant in the family Rosaceae, which grows widely in open fields Korea. It has been used as traditional medicine for thousands of years, as a treatment for anti-inflammatory and it is widely used for throat infection, tonsilitis, conjuctivitis and lymphadentis. In this study, investigated skin antiaging and anti-bacterial by using SO fractions water, acetone and butanol, chloroform. Methods : The effects of anti-microbial on SO fractions and elastase inhibition activity, collagenase inhibition activity were experimented. Results : 1. The ethyl acetate fraction showed the strongest antimicrobial activity against Staphylococcus epidermidis. 2. The elastase inhibition rate and collagenase inhibition rate of the water fraction of SO was the highest other factions. Conclusions : From the above results, it was confirmed the SO has sufficient potentiality applying itself to industry and also SO can be utilized as antimicrobial natural materials and antiaging cosmetics.

• Proceedings of the Turfgrass Society of Korea Conference
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• 2011.02a
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• pp.35-35
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• 2011

A large patch disease caused by Rhizoctonia solani AG2-2(IV) is a serious problem in turfgrass sites including golf courses and sports fields in Korea. The objectives of this study were to isolate some antagonistic microorganisms and to explain some involving mechanisms. Initially single colonies which were formed from the filtrates of various soil samples were obtained from LB culture and then co-cultured with R.solani AG2-2(IV) on PDA plate to explore some antagonistic microbes against for large patch fungus, Rhizoctonia solani AG2-2(IV). Out of total 82 antagonistic isolates which commonly had inhibition effect on Rhizoctonia solani AG2-2(IV) mycelial growth, one candidate (YPIN22) showed the most antifungal effect, which was confirmed by the longest distance from the edge of bacterial colony to the mycelial edge of the Rhizoctonia solani AG2-2(IV) in the dual culture. A succeeding investigation was to test any potential effect of the isolate on growth inhibition of 5 other turfgrass pathogens including R. solani solani AG2-2(IIIB), P. ultimum, C. caudatum, C. lunata, and F.oxysporum. Preliminary result indicated that the new isolate YPIN22 was also found to have antagonistic potential on the growth inhibition of those turfgrass pathogenic fungi, which was explained by inhibition zones ranging from 8 to 22mm. A further explanation of some characteristics of the isolate YPIN22 will be discussed in detail.

• Biomedical Science Letters
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• v.24 no.3
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• pp.270-274
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• 2018

Chlorine dioxide ($ClO_2$) gas is a neutral chlorine compound. $ClO_2$ gas was proven to effectively decontaminate different environments, such as hospital rooms, ambulances, biosafety level 3 laboratories, and cafeterias. In this study, to evaluate the effects of $ClO_2$ gas, bacteria of clinical importance were applied. Staphylococci, Streptococci and Bacillus strains were applied and Klebsiella, and others e.g., Escherichia coli, Shigella, Salmonella, Serratia were also done for the inhibitory analysis. Bacteria plates were applied with a hygiene stick, namely, "FarmeTok (Medistick/Puristic)" to produce $ClO_2$. $ClO_2$-releasing hygiene stick showed the very strong inhibition of bacterial growth but had different inhibitions to the bacteria above 96.7% except for MRSA of 90% inhibition. It is difficult to explain why the MRSA were not inhibited less than others at this point. It can be only suggested that more releasing $ClO_2$ should be essential to kill or inhibit the MRSA. B. subtilis, S. agalactiae, S. pyogenes, E. coli O157:H7, S. typhi (S. enterica serotype typhi) and S. marcesence were inhibited over 99%. This study will provide fundamental data to research growth inhibition by $ClO_2$ gas with bacteria of clinical importance value.

• Journal of Pharmacopuncture
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• v.25 no.1
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• pp.37-45
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• 2022

Objectives: The quorum-sensing-inhibitory and anti-biofilm activities of the methanol extract of E. globulus leaves were determined against clinically isolated multidrug-resistant Pseudomonas aeruginosa. Methods: The preliminary anti-quorum-sensing (AQS) activity of eucalyptus was investigated against a biosensor strain Chromobacterium violaceum ATCC 12472 (CV12472) by using the agar well diffusion method. The effect of sub-minimum inhibitory concentrations (sub-MICs) of the methanol extract of eucalyptus on different quorum-sensing-regulated virulence factors, such as swarming motility, pyocyanin pigment, exopolysaccharide (EPS), and biofilm formation, against clinical isolates (CIs 2, 3, and 4) and reference PA01 of Pseudomonas aeruginosa were determined using the swarm diameter (mm)-measurement method, chloroform extraction method, phenol (5%)-sulphuric acid (concentrated) method, and the microtiter plate assay respectively, and the inhibition (%) in formation were calculated. Results: The preliminary AQS activity (violacein pigment inhibition) of eucalyptus was confirmed against Chromobacterium violaceum ATCC 12472 (CV12472). The eucalyptus extract also showed concentration-dependent inhibition (%) of swarming motility, pyocyanin pigment, EPS, and biofilm formation in different CIs and PA01 of P. aeruginosa. Conclusion: Our results revealed the effectiveness of the E. globulus extract for the regulation of quorum-sensing-dependent virulence factors and biofilm formation at a reduced dose (sub-MICs) and suggest that E. globulus may be a therapeutic agent for curing and controlling bacterial infection and thereby reducing the possibility of resistance development in pathogenic strains.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.19 no.1
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• pp.1-10
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• 2006

This experimental study was performed to investigate the effect of herbal eye drops, Tangpo-san and Coptidis rhizoma on Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa keratitis. The following results were obtained by using Minimum inhibition Concentration(MIC) and inhibition Zone. 1. MIC on Staphylococcus aureus in Tangpo-san was 100%, in Coptidis rhizoma was 100% and in Cravit was 0.1% 2. MIC on Staphylococcus epidermidis in Tangpo-san was 100%, in Coptidis rhizoma was 10% and in Cravit was 0.1%. 3. MIC on Pseudomonas aeruginosa in Tangpo-san, Coptidis rhizoma was not showing and in Cravit was 0.1%. 4. The size of inhibition zone on Staphylococcus aureus for Tangpo-san was 13.3mm in $50{\mu}{\ell}$, for Coptidis rhizoma was 26mm in $50{\mu}{\ell}$ and for Cravit was 31mm in $50{\mu}{\ell}$, showing the highest antibacterial effect. 5. The size of inhibition zone on Staphylococcus epidermidis for Tangpo-san was 16mm in $50{\mu}{\ell}$, for Coptidis rhizoma was 25mm in $40{\mu}{\ell}$ and for Cravit was 34mm in $50{\mu}{\ell}$, showing the highest antibacterial effect. 6. The size of inhibition zone on Pseudomonas aeruginosa for Tangpo-san, Coptidis rhizoma was not and for Cravit was 24.7mm in $50{\mu}l$, showing the antibacterial effect. In addition, the results shows that the herbal eye drops, Tangpo-san and Coptidis rhizoma can be used to cure Staphylococcus aureus, Staphylococcus epidermidis keratitis and if further study is performed, the use of herbal eye drops will be valuable and beneficial in the clinical medicines.

• The Journal of Korean Obstetrics and Gynecology
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• v.27 no.1
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• pp.65-80
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• 2014

Objectives: The object of this study was to observe the in vitro antibacterial effects of Gagam-seopyoungjeon aqueous extracts (GGSYJ) against Gardnerella vaginalis and the possible synergic combination effects with clindamycin. Methods: Antibacterial activities against Gardnerella vaginalis of GGSYJ were detected using minimal inhibition concentration (MIC), and the effects on the bacterial growth curve were also monitored at MIC and MIC${\times}$2 levels. The combination effects of GGSYJ with clindamycin were observed by checkboard microtiter assay, and the effects of bacterial growth curve treated with GGSYJ MIC+clindamycin MIC, 1/2 MIC and 1/4 MIC, respectively. The effects on the bacterial invasion and intracellular killing of GGSYJ were also observed using human vaginal epithelial (VK2) and murine macrophage (Raw264.7) cells with combination effects with clindamycin after treatment of GGSYJ MIC+clindamycin 1/2 MIC, 1/4 MIC and 1/6 MIC, respectively. Results: The MIC of clindamycin and GGSYJ against Gardnerella vaginalis were detected as $0.012{\pm}0.006$ (0.004~0.016)${\mu}g/ml$ and $1.016{\pm}0.524$ (0.391~1.563) mg/ml, respectively. Clindamycin and GGSYJ were also showed marked dosage-dependent inhibition of bacterial growth, and significant decreases of viable cells were detected in clindamycin MIC+GGSYJ MIC and clindamycin 1/2 MIC+GGSYJ MIC treatment as compared with each of single clindamycin MIC and GGSYJ MIC treatments. And significant decreases of intraepithelial and intra-macrophage viable bacteria numbers were detected in clindamycin 1/2 MIC+GGSYJ 1/2 MIC and clindamycin 1/4 MIC+GGSYJ 1/2 MIC treatment as compared with each of single clindamycin GGSYJ 1/2 MIC treatments, respectively. Conclusions: GGSYJ showed slight antibacterial effects against Gardnerella vaginalis, but they showed dosage-dependent inhibitory effects on the bacterial growth and VK2 epithelial invasions of bacteria with favorable accelerating effects of intracellular killing activities of macrophages. In addition, combination of GGSYJ also increased the inhibitory effects of clindamycin on the epithelial invasions of Gardnerella vaginalis and intracellular killing activities of macrophages against Gardnerella vaginalis as 2-fold higher as compared with clindamycin single treatment, respectively. Therefore, we expected that the clinical dosages of clindamycin can be reduced as 1/2 levels as combination with GGSYJ.

• KSBB Journal
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• v.16 no.1
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• pp.41-47
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• 2001

H. pylori is known to be a key pathogen of chronic gastric and duodenal ulcers. Bacterial adhesion to hosts is an essential step for bacterial infection and the inhibition of this adhesion provides a possible method for the treatment of the infection. The inhibitory effect of antibody lgY, produced from immunized hens with H. pylori antigen, was studied in vitro. The inhibition of H. pylori adhesion to AGS was as high as 90% using 0.5mg/ml of lgY, and almost 80% of the detachmentwas also achieved. The inhibitory effect of adhesion-inhibition candidates was investigated. Additives in combination with lgY increased the adhesion-inhibiting effect by about 30-50%. However, the adhesion molecules of H. pylori were varied and complex, therefore the further studies are necessary to develop an adhesion inhibitor and effective enough to be employed for the treatment of H.pylori, in vivo.

• Korean Journal of Veterinary Research
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• v.52 no.1
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• pp.33-38
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• 2012

Germanium biotite, a natural mineral, has been used as a feed supplement to reinforce innate immune ability. The aim of the present study was to evaluate the effects of germanium biotite on the adsorptive and inhibition of growth abilities against Escherichia (E.) coli and Salmonella spp. in vitro. Two strains of enterotoxigenic E. coli and four strains of two Salmonella serotypes (Salmonella Derby and Salmonella Typhimurium), major bacterial diarrheal pathogens, were used for this experiment. The absorptive ability of germanium biotite against most Salmonella used in present experiment was observed weakly. The germanium biotite, however, showed significant effect of bacterial growth inhibition in most experiment bacteria. These results suggest that the use of the germanium biotite as feed supplement could alleviate diarrhea following inhibition of bacteria growth. It is also presumed that antibiotics usage for farm animals, considered as causes of antibiotic residue in meat and emerging antibiotic resistance, could be reduced through the use of germanium biotite as a feed supplement, in place of antibiotics used for the prevention of diarrhea.

• Journal of Veterinary Science
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• v.25 no.3
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• pp.47.1-47.12
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• 2024

Importance: Staphylococcus aureus and Escherichia coli contribute to global health challenges by forming biofilms, a key virulence element implicated in the pathogenesis of several infections. Objective: The study examined the efficacy of various generations of cephalosporins against biofilms developed by pathogenic S. aureus and E. coli. Methods: The development of biofilms by both bacteria was assessed using petri-plate and microplate methods. Biofilm hydrolysis and inhibition were tested using first to fourth generations of cephalosporins, and the effects were analyzed by crystal violet staining and phase contrast microscopy. Results: Both bacterial strains exhibited well-developed biofilms in petri-plate and microplate assays. Cefradine (first generation) showed 76.78% hydrolysis of S. aureus biofilm, while significant hydrolysis (59.86%) of E. coli biofilm was observed by cefipime (fourth generation). Similarly, cefuroxime, cefadroxil, cefepime, and cefradine caused 78.8%, 71.63%, 70.63%, and 70.51% inhibition of the S. aureus biofilms, respectively. In the case of E. coli, maximum biofilm inhibition (66.47%) was again shown by cefepime. All generations of cephalosporins were more effective against S. aureus than E. coli, which was confirmed by phase contrast microscopy. Conclusions and Relevance: Cephalosporins exhibit dual capabilities of hydrolyzing and inhibiting S. aureus and E. coli biofilms. First-generation cephalosporins exhibited the highest inhibitory activity against S. aureus, while the third and fourth generations significantly inhibited E. coli biofilms. This study highlights the importance of tailored antibiotic strategies based on the biofilm characteristics of specific bacterial strains.