• International Journal of Oral Biology
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• v.31 no.1
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• pp.7-10
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• 2006

Mitis-salivarius sucrose bacitracin(MSB) medium is widely used in the selective isolation of mutans streptococci(MS), a designation for a group of oral cariogenic species. Recently, we have isolated three bacterial strains grown on MSB agar from human dental plaques. The three strains exhibited biochemical characteristics similar to those of the biotype IV of MS, with the exception that they manifested a positive reaction for arginine deaminase. The objective of this study was to identify and characterize these three clinical isolates. The bacteria were identified with biochemical tests as well as by 16S rDNA cloning and sequencing. In order to compare the antibiotics susceptibility of the clinical isolates with that of type strain, the minimum inhibitory concentrations of 9 antibiotics were determined using broth dilution assays. The results identified all of our three clinical isolates as Enterococcus faecalis. All E. faecalis strains were found to be susceptible to penicillin G, amoxicillin, augmentin, and vancomycin, but were resistant to ciprofloxacin, cefuroxim axetil, and clindamycin. Our findings indicate that E. faecalis is capable of growing on MSB agar, and suggest that the MSB medium be improved so that only MS should be recoverable on the medium, as originally devised for their selection.

• International Journal of Oral Biology
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• v.39 no.2
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• pp.87-95
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• 2014

The purpose of this study was to isolate and identify bacteria from the 4 patients with non-odontogenic infectious lesions (mucormycosis, chronic inflammation from wound infection, and two actinomycosis) and determine their antimicrobial susceptibility against eight antibiotics. Bacterial culture was performed under three culture conditions (anaerobic, $CO_2$, and aerobic incubator). The bacterial strains were identified by 16S rRNA gene (16S rDNA) sequence comparison analysis method. For investigating the antimicrobial susceptibility of the bacteria against eight antibiotics, penicillin G, amoxicillin, tetracycline, cefuroxime, erythromycin, clindamycin, vancomycin, and Augmentin$^{(R)}$ (amoxicillin + clavulanic acid), minimum inhibitory concentration (MIC) measurement was performed using broth microdilution assay. Nosocomial pathogens such as Enterococcus faecalis, Klebsiella pneumoniae, Bacillus subtilis, and Neisseria flavescens were isolated from mucormycosis. Veillonella parvula, Enterobacter hormaechei, and Acinetobacter calcoaceticus were isolated from chronic inflammatory lesion. Actinomyces massiliensis was isolated from actinomycosis in parotid gland. Capnocytophaga ochracea was isolated from actinomycosis in buccal region in anaerobic condition. There was no susceptible antibiotic to all bacteria in mucormycosis. Tetracycline was susceptible to all bacteria in chronic inflammation. C. ochracea was resistant to vancomycin and penicillin G; and other antibiotics showed susceptibility to all bacteria in actinomycosis. The results indicated that the combined treatment of two or more antibiotics is better than single antibiotic treatment in mucormycosis, and penicillin is the first recommended antibiotic to treat actinomycosis.

• Journal of Periodontal and Implant Science
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• v.52 no.2
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• pp.141-154
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• 2022

Purpose: C57BL/6 mice, which are among the most common backgrounds for genetically engineered mice, are resistant to the induction of periodontitis by oral infection with periodontal pathogens. This study aimed to develop a periodontitis model in C57BL/6 mice using coaggregation between human pathogens and the mouse oral commensal Streptococcus danieliae (Sd). Methods: The abilities of Porphyromonas gingivalis ATCC 33277 (Pg33277), P. gingivalis ATCC 49417 (Pg49417), P. gingivalis KUMC-P4 (PgP4), Fusobacterium nucleatum subsp. nucleatum ATCC 25586 (Fnn), and F. nucleatum subsp. animalis KCOM 1280 (Fna) to coaggregate with Sd were tested by a sedimentation assay. The Sd-noncoaggregating Pg33277 and 2 Sd-coaggregating strains, PgP4 and Fna, were chosen for animal experiments. Eighty C57BL/6 mice received oral gavage with Sd once and subsequently received vehicle alone (sham), Fna, Pg33277, PgP4, or Fna+PgP4 6 times at 2-day intervals. Mice were evaluated at 5 or 8 weeks after the first gavage of human strains. Results: Fnn, Fna, and PgP4 efficiently coaggregated with Sd, but Pg33277 and Pg49417 did not. Alveolar bone loss was significantly higher in the PgP4 group at both time points (weeks 5 and 8) and in all experimental groups at week 8 compared with the sham group. The PgP4 group presented greater alveolar bone loss than the other experimental groups at both time points. A higher degree of alveolar bone loss accompanied higher bacterial loads in the oral cavity, the invasion of not only PgP4 but also Sd and Fna, and the serum antibody responses to these bacteria. Conclusions: Periodontitis was successfully induced in C57BL/6 mice by oral infection with a P. gingivalis strain that persists in the oral cavity through coaggregation with a mouse oral commensal bacterium. This new model will be useful for studying the role of human oral bacteria-host interactions in periodontitis using genetically engineered mice.

• International Journal of Oral Biology
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• v.45 no.3
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• pp.77-83
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• 2020

In the oral cavity, complex microbial community is shaped by various host and environmental factors. Extensive literature describing the oral microbiome in the context of oral health and disease is available. Advances in DNA sequencing technologies and data analysis have drastically improved the analysis of the oral microbiome. For microbiome study, bacterial 16S ribosomal RNA gene amplification and sequencing is often employed owing to the cost-effective and fast nature of the method. In this review, practical considerations for performing a microbiome study, including experimental design, molecular analysis technology, and general data analysis, will be discussed.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.677-684
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• 2001

To isolate mutanse-producing bacteria, soil samples were collected from several areas in chonnam Province, South Korea. A total of 70 strains of actinomycetes were isolated from the soil samples. All isolated actinomycetes were inoculated on mutanase screening media to identify new bacterial strains producing mutanase activity. One strain in particular exhibited a strong mutanase-producing activity, and was identified as Microbispora rosea based on its morphological, cultural, and physiological characteristics, and also by 16S rDNA sequences.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2004.06a
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• pp.142-142
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• 2004

• Journal of Korean society of Dental Hygiene
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• v.9 no.3
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• pp.306-318
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• 2009

Objectives : There were reports about the decreasing of quit-smoking ratio because of taking professional advices. This study were to investigate smoking prevalence rate of the dental hygienist study in nationwide and quit-smoking counseling activity for patients in dental clinic. Methods : The registered Korea Dental Hygienists Association Meeting in 2005 were recruited as subjects. The personal surveyed, 486(87.7%) returned completed questionnaires. Results : The smoking rate of dental hygienist is 3.1%, past smoking rate 1.4% and smoking cessation 95.5%. In smoking cessation counseling activity, only 20.8% of dental hygienist would advise to quit smoking. However, 63.8% intended to advise to quit smoking but they have no idea about quit smoking program and 15.4% had no intention of advising to quit. It is a whole consent that Smoking dental hygienist is tend to against smoking and necessary training about smoking cessation same opinion. Conclusions : Dental hygienist is more effective for health care professional to help people stop smoking, therefore dental hygienist is important for them to have through knowledge of subject and confidence in their role in smoking cessation.

• Journal of Microbiology
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• v.43 no.4
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• pp.331-336
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• 2005

The objective of this study was to assess the strain-specificity of a DNA probe, Fu12, for Fusobacterium nucleatum subsp. nucleatum ATCC $25586^T$ (F. nucleatum ATCC $25586^T$), and to develop sets of strain-specific polymerase chain reaction (PCR) primers. Strain-specificity was tested against 16 strains of F. nucleatum and 3 strains of distinct Fusobacterium species. Southern blot hybridization revealed that the Fu12 reacted exclusively with the HindIII-digested genomic DNA of F. nucleatum ATCC $25586^T$. The results of PCR revealed that three pairs of PCR primers, based on the nucleotide sequence of Fu12, generated the strain-specific amplicons from F. nucleatum ATCC $25586^T$. These results suggest that the DNA probe Fu12 and the three pairs of PCR primers could be useful in the identification of F. nucleatum ATCC $25586^T$, especially with regard to the determination of the authenticity of the strain.

• Journal of Microbiology and Biotechnology
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• v.26 no.10
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• pp.1817-1823
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• 2016

Areca nut (AN) chewing is a habit in many countries in Central, Southern, and Southeast Asia. It is strongly associated with the occurrence of oral, pharyngeal, and esophageal cancer as well as systemic inflammation. However, the association between AN intake and the development of gastric lesions has not yet been identified. The aim of this study was to investigate the effect of AN on gastric diseases using a mouse model for Helicobacter pylori infection. We studied four groups of mice: those fed a normal diet (ND), those fed a diet containing 2.5% AN (AD), those fed ND and infected with H. pylori PMSS1 strain (ND/HP), and those fed AD and infected with H. pylori PMSS1 strain (AD/HP). Food intake and body weight were monitored weekly during the experiments. At 10 weeks, the mice were sacrificed, and the stomach weight, H. pylori colonization, and gastric inflammation were evaluated. The stomach weight had increased significantly in the ND/HP and AD/HP groups along with increases in H. pylori colonization; however, there was no significant difference between these two groups with respect to stomach weight and colonization. On histological grading, mononuclear cell infiltration was severer in the AD/HP group than in the ND/HP group. These data suggest that chronic gastric inflammation was aggravated by AN treatment in the mice with H. pylori-induced gastric lesions. Furthermore, as previously suggested, this animal model is useful to determine the effect of potential carcinogens on gastric lesions induced by H. pylori infection.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.2
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• pp.105-110
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• 2016

Oral mucormycosis is a fungal infection observed mainly in elderly immunocompromised patients. In rare instances, the disease occurs in healthy individuals and those patients that are below preschool age. Although this condition mainly involves the maxilla, it may also manifest in any part of the oral cavity based on the source of infection. Mucormycosis of the maxilla spreads rapidly, leading to necrosis of the palatal bone and palatal perforation. Such patients are usually rehabilitated using bone grafting or free flap surgeries. However, when surgeries are delayed, palatal prosthesis is an interim treatment modality that can prevent nasal regurgitation and aspiration of food or fluids. Palatal prostheses also help with mastication, speech, and swallowing. The present case describes a rare case of oral mucormycosis in an 18-month-old male involving the maxilla that was managed by palatal prosthesis.