• The Journal of the Korean Society for Microbiology
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• v.12 no.1
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• pp.1-10
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• 1977

40 strains of E. coli isolated from residents of a doctorless area in Korea in 1976 and 40 strains of E. coli isolated from patients of Seoul National University Hospital from 1975 to 1976 were examined for susceptibilities to 14 antimicrobial agents by the agar dilution method. The susceptibilities of the two groups to each antimicrobial agent were compared and correlations in the antimicrobial susceptibility of the 80 strains of E. coli among the 14 antimicrobial agents were also analyzed. The results were obtained as follow: 1. With Tetracycline, Oxytetracycline, Doxycycline and Ampicillin, the mean MIC's of E. coli isolated from patients of Seoul National University Hospital were 8.6 to 14 times higher than. those of E. coli isolated from residents of a doctorless area. 2. With Streptomycin, Minocycline and Carbenicillin, the mean MIC's o{ E. coli isolated from patients of Seoul National University Hospital were 4.1 to 5.6 times higher than those of E. coil isolated from residents of a doctorless area. 3. With Kanamycin, Penicillin and Cotrimoxazole, the mean MIC's of E. coli isolated from patients of Seoul National University Hospital were 2.6 to 3.7 times higher than those of E. coli isolated from residents of a doctorless area. 4. There were no significant differences in susceptibility to Erythromycin respectively between E. coli isolated from patients of Seoul National University coli isolated from residents of a doctorless area. 5. E. coli isolated from patients of Seoul National University Hospital were resistant to Erythromycin(100%), Streptomycin(75%), Tetracycline(72.5%), Oxytetracycline(72.5%), Doxycycline(72.5%), Minocycline(67.5%), Penicillin(82.5%), Ampicillin(60%) and Carbenicillin(65%) respectively and were sensitive to Gentamicin(97.5%), Cephalexin(92.5%) and Kanamycin(72.5%) respectively. 6. E. coli isolated from residents of a doctorless, area were resistant to Erythromycin(100%), Streptomycin(40%) and Penicillin(50%) respectively and were sensitive to Gentamicin(100%), Kanamycin(92.5%), Tetracycline(87.5%), Oxytetracycline(87.5%), Doxycycline(87.5%), Minocycline(87.5%), Ampicillin(95%), Carbenicillin(92.5%) and Cephalexin(97.5%) respectively. 7. There were high correlations among the suscebtibilities of the 80 strains of E. coli to Tetracycline analogues(Tetracycline, Oxytetracycline, Doxycycline and Minocycline) and among susceptibilities of the 80 strains of E. coli to Penicillin analogues(Penicillin, Ampicillin and Carbenicillin). 8. There were relatively high correlations between the susceptibilities of the 80 strains of E. coli to Penicillin analogues and those to Tetracycline analogues, between the susceptibilities to Penicillin analogues and those to Streptomycin and between the susceptibilities to Tetracycline analogues and those to Streptomycin.

• Journal of Periodontal and Implant Science
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• v.29 no.3
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• pp.677-693
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• 1999

Extracellular matrix component is degraded by enzymes of thematrix metalloproteinases(MMPs). MMPs are produced by both hemopoietic and structural cells. Increased activity of MMP-3 in periodontium is strongly associated with inflammatory periodontal disease. The purpose of the present study was to determine the effect of tetracycline analogues on the activity of MMP-3. Tetracycline-HCl, doxycycline-HCl, and minocycline-HCl were applied to huamn gingival fibroblasts at various concentrations of 10, 25, 50, 100, 200${\mu}g$/ml, and 1 hour later IL-$1{\beta}$ of 25ng/ml was added. After incubation for 24 hours the cells were reacted by enzyme-linked immunosorbent assay using proMMP-3 ELISA kit. The optical density was measured by microwell plate reader at 450nm. The relative activity of MMP-3 was calculated as the percentage of the optical density of each experimental group to that of the control. The difference of the optical density and the relative activity of MMP-3 between the experimental groups and the control wasstatistically analyzed by one way ANOVA. The results were as follows: 1. Tetracycline-HCl showed the tendency to inhibit the activity of MMP-3 at the concentration lower than 25${\mu}g$/ml, but increased significantly the activity of MMP-3 at the concentration of 200${\mu}g$/ml(p<0.05). 2. Doxycycline-HCl inhibited significantly the activity of MMP-3 at the concentration lower than 100${\mu}g$/ml, but increased significantly the activity of MMP-3 at the concentration of 200${\mu}g$/ml(p<0.05). 3. Minocycline-HCl inhibited the activity of MMP-3 at the concentration in the range of 10 to 200${\mu}g$/ml. Within the limit of the present study, the above results suggested that the low concentration of tetracycline analogues could inhibit the activity of MMP-3 induced by IL-$1{\beta}$ in human gingival fibroblasts.

• The Journal of the Korean Society for Microbiology
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• v.13 no.1
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• pp.63-73
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• 1978

28 strains of Enterococci isolated at doctorless areas in Korea from Oct. 1976 through Mar. 1977 and 30 strains of Enterococci isolated at Seoul National University Hospital from Sep. 1976 through Dec. 1976 were examined for susceptibilities to 14 antimicrobial agents by agar dilution method. The susceptibilities of two groups to each antimicrobial agent were compared and incidence of resistant strains in each antimicrobial agent, incidence of multiply resistant strains and correlations in the antimicrobial susceptibility of 58 strains of Enterococci among 14 antimicrobial agents were analyzed. 1. With Tetracycline, Oxytetracline, Doxycycline, Minocycline and Erythromycin, the mean MIC's of Enterococci isolated at Seoul National University Hospital were 1.9-2.5 times higher than those of Enterococci isolated at doctorless areas, though there were no statistical significance. 2. Frequency of resistant strains in Enterococci isolated at Seoul National University Hospital was the highest with Cephalexin(100%), Gentamicin(100%), and Streptomycin(100%), followed by Kanamycin(93.3%), Carbenicillin(90%), Tetracycline(26.7%), Oxytetracycline(26.7%), Doxycycline(26.7%), Minocycline(20%), Erythromycin(10%), Troleandomycin(10%), Penicillin(6.7%), Cotrimoxazole(6.7%) and Ampicillin(0%). 3. Frequency of resistant strains in Enterococci isolated at doctorless areas was the highest with Kanamycin(100%) and Streptomycin(100%), followed by Cephalexin(96.4%), Gentamicin(96.4%), Carbenicillin(92.9%), Tetracycline(10.7%), Oxytetracycline(10.7%), Doxycycline(10.7%), Minocycline(10.7%), Cotrimoxazole(10.7%), Penicillin(3.6%), Ampicillin(0%), Erythromycin(0%), and Troeandomycin(0%). 4. In study with Penicillin, Ampicillin, Tetracycline, Cotrimoxazole, Erythromycin and Troleandomycin, there were no multiply resistant strains in Enterococci isolated at doctorless areas, while 4 strains of Enterococci isolated at Seoul National University Hospital showed multiple resistance. 5. There were high correlation in susceptibility of 58 strains of Enterococci among Tetracycline, Oxytetracycline, Doxycycline and Minocycline(correlation coefficients 0.86-0.97). Correlation coefficients of susceptibility among penicillin analogues(Penicillin, Ampicillin, Carbenicillin and Cephalexin) ranged between 0.75-0.89. Correlation coefficients of susceptibility among aminoglycosides(Kanamycin, Gentamicin and Streptomycin) ranged between 0.09-0.51.

• Journal of Periodontal and Implant Science
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• v.39 no.1
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• pp.37-44
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• 2009

Purpose: Tetracycline and its chemically modified non-antibacterial analogues can inhibit certain host-derived tissue destructive collagenases such as matrix metalloproteinases. The purpose of this study was to evaluate clinical and microbiologic effects of the subantimicrobial dose of doxycycline(SDD) in conjunction with scaling and root planing. Materials and methods: A total of 30 patients with chronic periodontitis who were going to receive scaling and root planing were randomly allocated to receive either a doxycycline hyclate for 3 months or nothing. Clinical probing depth, clinical attachment level, gingival recession, and bleeding on probing were measured by one periodontist. After a periodontal examination, microbial samples were collected using sterile paper points. The effect of SDD in conjunction with scaling and root planing on alterations of the periodontal pathogens (Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Porphyromonas gingivalis) were also assessed using l6S rRNA polymerase chain reaction. Results: During the treatment period, clinical parameters for both treatment group and control group were improved. After 3 months, reductions in probing depth and gains in clinical attachment level were significantly greater for the SDD group than control group. Microbial analysis showed that there was no alteration of the periodontal pathogens and no difference between the groups. Conclusion: This study suggested that the subantimicrobial dose of doxycycline as an adjunct therapy with scaling and root planing might be effective and safe in the management of chronic periodontitis.