• Journal of Veterinary Clinics
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• v.36 no.2
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• pp.98-101
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• 2019

Lactobacillus spp. are the bacteria most commonly used as probiotics and it has been proven that they inhibit pathogenic bacterial growth and improve skin repair in humans. This study was conducted to investigate the growth inhibitory effect of Lactobacillus on Staphylococcus pseudintermedius, the most commonly isolated pathogen in canine pyoderma, and whether Lactobacillus could inhibit the adhesion capability of S. pseudintermedius to canine corneocytes. For this study, L. salivarius and S. pseudintermedius were isolated from healthy beagle fecal samples and the skin surface of dogs with skin infection, respectively. S. pseudintermedius was co-cultured with L. salivarius to assess the inhibitory effect. For the adhesion assay, corneocytes were collected from healthy beagle ventral abdominal skin. Both bacterial species attached to corneocytes and were assessed in number. As a result, L. salivarius significantly inhibited the growth of S. pseudintermedius in the culture medium. Moreover, L. salivarius reduced attachment of S. pseudintermedius in the adhesion assay. These results suggest that L. salivarius has an inhibitory effect on S. pseudintermedius and may be effectively used in the topical therapy of canine skin infections.

• Macromolecular Research
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• v.16 no.5
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• pp.473-480
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• 2008

In this study we investigated bacterial and cell adhesion to poly(propylene carbonate) (PPC) films, that had been synthesized by the copolymerization of carbon dioxide (a global warming chemical) with propylene oxide. We also assessed the biocompatibility and biodegradability of the films in vivo, and their oxidative degradation in vitro. The bacteria adhered to the smooth, hydrophobic PPC surface after 4 h incubation. Pseudomonas aeruginosa and Enterococcus faecalis had the highest levels of adhesion, Escherichia coli and Staphylococcus aureus had the lowest levels, and Staphylococcus epidermidis was intermediate. In contrast, there was no adhesion of human cells (cell line HEp-2) to the PPC films, due to the hydrophobicity and dimensional instability of the surface. On the other hand, the PPC films exhibited good biocompatibility in the mouse subcutaneous environment. Moreover, contrary to expectation the PPC films degraded in the mouse subcutaneous environment. This is the first experimental confirmation that PPC can undergo surface erosion biodegradation in vivo. The observed biodegradability of PPC may have resulted from enzymatic hydrolysis and oxidative degradation processes. In contrast, the PPC films showed resistance to oxidative degradation in vitro. Overall, PPC revealed high affinity to bioorganisms and also good bio-degradability.

• Journal of Microbiology and Biotechnology
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• v.31 no.4
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• pp.592-600
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• 2021

Probiotics can be processed into a powder, tablet, or capsule form for easy intake. They are exposed to frequent stresses not only during complex processing steps, but also in the human body after intake. For this reason, various coating agents that promote probiotic bacterial stability in the intestinal environment have been developed. Silk fibroin (SF) is a material used in a variety of fields from drug delivery systems to enzyme immobilization and has potential as a coating agent for probiotics. In this study, we investigated this potential by coating probiotic strains with 0.1% or 1% water-soluble calcium (WSC), 1% SF, and 10% trehalose. Under simulated gastrointestinal conditions, cell viability, cell surface hydrophobicity, and cell adhesion to intestinal epithelial cells were then measured. The survival ratio after freeze-drying was highest upon addition of 0.1% WSC. The probiotic bacteria coated with SF showed improved survival by more than 10.0% under simulated gastric conditions and 4.8% under simulated intestinal conditions. Moreover, the cell adhesion to intestinal epithelial cells was elevated by 1.0-36.0%. Our results indicate that SF has positive effects on enhancing the survival and adhesion capacity of bacterial strains under environmental stresses, thus demonstrating its potential as a suitable coating agent to stabilize probiotics throughout processing, packaging, storage and consumption.

• Journal of Microbiology and Biotechnology
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• v.25 no.6
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• pp.771-781
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• 2015

To examine if the molecular chaperone DnaK operon proteins of Streptococcus suis type 2 (SS2) are involved in adhesion to host cells, the abundance values of these proteins from the surface of two SS2 strains of different adhesion capability were compared. Their roles in growth and adhesion to human laryngeal epithelial cell line HEp-2 cells were investigated on SS2 strain HA9801 and its mutants with DnaK operon genes partially knocked-out (PKO mutant) under heat stress. The major difference was that DnaJ was more abundant in strain HA9801 than in strain JX0811. Pretreatment of the bacteria with hyperimmune sera to DnaJ, but not with those to other proteins, could significantly reduce SS2 adhesion to HEp-2 cells. PKO of dnaJ g ene resulted in decreased SS2 growth at 37℃ and 42℃, and reduced its adhesion to HEp-2 cells. The wild-type strain stressed at 42℃ had increased expression of DnaJ on its surface and elevated adhesion to HEp-2 cells, which was also inhibitable by DnaJ specific antiserum. These results indicate that the DnaJ of S. suis type 2 is important not only for thermotolerance but also for adhesion to host cells. Because DnaJ expression is increased upon temperature upshift with increased exposure on the bacterial surface, the febrile conditions of the cases with systemic infections might help facilitate bacterial adhesion to host cells. DnaJ could be one of the potential candidates as a subunit vaccine because of its good immunogenicity.

• International Journal of Oral Biology
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• v.44 no.2
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• pp.31-36
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• 2019

Streptococcus mutans is one of the important bacteria that forms dental biofilm and cause dental caries. Virulence genes in S. mutans can be classified into the genes involved in bacterial adhesion, extracellular polysaccharide formation, biofilm formation, sugar uptake and metabolism, acid tolerance, and regulation. The genes involved in bacterial adhesion are gbps (gbpA, gbpB, and gbpC) and spaP. The gbp genes encode glucan-binding protein (GBP) A, GBP B, and GBP C. The spaP gene encodes cell surface antigen, SpaP. The genes involved in extracellular polysaccharide formation are gtfs (gtfB, gtfC, and gtfD) and ftf, which encode glycosyltransferase (GTF) B, GTF C, and GTF D and fructosyltransferase, respectively. The genes involved in biofilm formation are smu630, relA, and comDE. The smu630 gene is important for biofilm formation. The relA and comDE genes contribute to quorumsensing and biofilm formation. The genes involved in sugar uptake and metabolism are eno, ldh, and relA. The eno gene encodes bacterial enolase, which catalyzes the formation of phosphoenolpyruvate. The ldh gene encodes lactic acid dehydrogenase. The relA gene contributes to the regulation of the glucose phosphotransferase system. The genes related to acid tolerance are atpD, aguD, brpA, and relA. The atpD gene encodes $F_1F_0$-ATPase, a proton pump that discharges $H^+$ from within the bacterium to the outside. The aguD gene encodes agmatine deiminase system and produces alkali to overcome acid stress. The genes involved in regulation are vicR, brpA, and relA.

• The Journal of Advanced Prosthodontics
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• v.11 no.1
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• pp.41-47
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• 2019

PURPOSE. Surface finishing of a zirconia restoration is essential after clinical adjustment. Herein, we investigated the effects of a surface finishing protocol for monolithic zirconia on final roughness and bacterial adherence. MATERIALS AND METHODS. Forty-eight disk-shaped monolithic zirconia specimens were fabricated and divided into four groups (n = 12) based on initial surface treatment, finishing, and polishing protocols: diamond bur+polishing bur (DP group), diamond bur+stone grinding bur+polishing bur (DSP group), no diamond bur+polishing bur (NP group), and no diamond bur+stone grinding bur+polishing bur (NSP group). Initial and final surface roughness was measured with a profilometer, and shown using scanning electron microscope. Bacterial adhesion was evaluated by quantifying Streptococcus mutans in the biofilm. Kruskal-Wallis and Mann-Whitney U tests were used to compare results among groups, and two-way analysis of variance was used to evaluate the effects of grinding burs on final roughness (${\alpha}=.05$). RESULTS. The DP group had the highest final Ra value, followed by the DSP, NP, and NSP groups. Use of the stone grinding bur as a coarse-finishing step significantly decreased final Ra values when a diamond bur was used (P<.001). Omission of the stone grinding bur increased biofilm formation on specimen surfaces. Combining a stone grinding bur with silicone polishing burs produced the smallest final biofilm values, regardless of the use of a diamond bur in initial surface treatment. CONCLUSION. Coarse finishing of monolithic zirconia with a stone grinding bur significantly decreased final Ra values and bacterial biofilm formation when surfaces had been roughened by a diamond bur.

• Polymer(Korea)
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• v.30 no.3
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• pp.247-252
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• 2006

The long-term use of indwelling urinary catheters can allow bacterial adhesion to their surfaces, followed by the catheter-associated urinary tract infection. In an attempt to minimize the bacterial adhesion, various amphiphilic polyurethanes (APUs) were synthesized as potential coating materials for urinary catheters. By varying composition of the soft segments such as PEO, PTMO, and PDMS, four different polyurethanes were synthesized. All the APU-coated urinary catheters had the smooth surfaces and showed higher hydrophilicity, compared to the commercial silicone catheters. In particular, the use of APUs with the higher PEG content significantly augmented hydrophilicity and remarkably reduced the total amount of bacteria adhering to the surface. Overall, the APUs prepared in this study provided the promising potential as coating materials for urinary catheters.

• 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.

• The Journal of Advanced Prosthodontics
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• v.3 no.2
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• pp.81-84
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• 2011

PURPOSE. The aim of this in vitro study was to investigate the adhesion of initial colonizer, Streptococcus sanguis, on resin, titanium and zirconia under the same surface polishing condition. MATERIALS AND METHODS. Specimens were prepared from Z-250, cp-Ti and 3Y-TZP and polished with $1 {\mu}m$ diamond paste. After coating with saliva, each specimen was incubated with Streptococcus sanguis. Scanning electron microscope, crystal violet staining and measurement of fluorescence intensity resulting from resazurin reduction were performed for quantifying the bacterial adhesion. RESULTS. Surface of resin composite was significantly rougher than that of titanium and zirconia, although all tested specimens are classified as smooth. The resin specimens showed lower value of contact angle compared with titanium and zirconia specimens, and had hydrophilic surfaces. The result of scanning electron microscopy demonstrated that bound bacteria were more abundant on resin in comparison with titanium and zirconia. When total biofilm mass determined by crystal violet, absorbance value of resin was significantly higher than that of titanium or zirconia. The result of relative fluorescence intensities also demonstrated that the highest fluorescence intensity was found on the surface of resin. Absorbance value and fluorescence intensity on titanium was not significantly different from those on zirconia. CONCLUSION. Resin specimens showed the roughest surface and have a significantly higher susceptibility to adhere Streptococcus sanguis than titanium and zirconia when surfaces of each specimen were polished under same condition. There was no significant difference in bacteria adhesion between titanium and zirconia in vitro.

• Journal of Microbiology and Biotechnology
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• v.33 no.3
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• pp.329-338
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• 2023

Enterohemorrhagic Escherichia coli (EHEC) is a foodborne pathogen that produces attaching and effacing lesions on the large intestine and causes hemorrhagic colitis. It is primarily transmitted through the consumption of contaminated meat or fresh produce. Similar to other bacterial pathogens, antibiotic resistance is of concern for EHEC. Furthermore, since the production of Shiga toxin by this pathogen is enhanced after antibiotic treatment, alternative agents that control EHEC are necessary. This study aimed to discover alternative treatments that target virulence factors and reduce EHEC toxicity. The locus of enterocyte effacement (LEE) is essential for EHEC attachment to host cells and virulence, and most of the LEE genes are positively regulated by the transcriptional regulator, Ler. GrlA protein, a transcriptional activator of ler, is thus a potential target for virulence inhibitors of EHEC. To identify the GrlA inhibitors, an in vivo high-throughput screening (HTS) system consisting of a GrlA-expressing plasmid and a reporter plasmid was constructed. Since the reporter luminescence gene was fused to the ler promoter, the bioluminescence would decrease if inhibitors affected the GrlA. By screening 8,201 compounds from the Korea Chemical Bank, we identified a novel GrlA inhibitor named Grlactin [3-[(2,4-dichlorophenoxy)methyl]-4-(3-methylbut-2-en-1-yl)-4,5-dihydro-1,2,4-oxadiazol-5-one], which suppresses the expression of LEE genes. Grlactin significantly diminished the adhesion of EHEC strain EDL933 to human epithelial cells without inhibiting bacterial growth. These findings suggest that the developed screening system was effective at identifying GrlA inhibitors, and Grlactin has potential for use as a novel anti-adhesion agent for EHEC while reducing the incidence of resistance.