• International Journal of Oral Biology
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• 제35권1호
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• pp.7-12
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• 2010

The aims of this study were to investigate the nosocomial infection route of methicillin-resistant Staphylococcus aureus (MRSA) and explore preventative methods for this pathogen that involve blocking its dispersion. We cultured MRSA from nasal cavity swabs collected between June and July 2008 that we obtained from eight dental healthcare providers, 32 nurses and the sputum specimens of two patients from our hospital. In addition, we used VITEK 2 equipment to measure drug sensitivity, and we further performed biochemical testing and pulse-field gel electrophoresis (PFGE) to isolate MRSA colonies. The incidence of these bacteria on the nasal swabs was 25.0% from dental clinic healthcare providers, 13.6% from the internal medicine ward nurses and 30.0% from intensive care unit nurses. Moreover, MRSA was detectable in sputum specimens of ward patients. The antimicrobial agents resistance and partial PFGE types of MRSA showed a similar pattern. We suggest from these analyses that nasal cavity infection by MRSA could occur by cross contamination between healthcare providers and patients which underscores the importance of stringent MRSA management practices.

• 한국미생물·생명공학회지
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• 제47권4호
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• pp.651-661
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• 2019

Targeting the pathogen viability using drugs is associated with development of drug resistance due to selective pressure. Hence, there is an increased interest in developing agents that target bacterial virulence. In this study, the inhibitory effect of ciclopirox, an antifungal agent with iron chelation potential, on the microbial virulence factors was evaluated in 26 clinical MDR Pseudomonas aeruginosa isolates collected from Alexandria Main University Hospital, a tertiary hospital in Egypt. Treatment with 9 ㎍/ml ciclopirox inhibited the hemolytic activity in 70% isolates, reduced pyocyanin production, decreased protease secretion in 46% isolates, lowered twitching and swarming motility, and decreased biofilm formation by 1.5- to 4.5-fold. The quantitative real-time PCR analysis revealed that treatment with ciclopirox downregulated the expression levels of alkaline protease (aprA) and pyocyanin (phzA1). Ciclopirox is used to treat hematological malignancies and the systemic administration of ciclopirox is reported to have adequate oral absorption with a satisfactory drug safety profile. It is important to calculate the appropriate clinical dose and therapeutic index to reposition ciclopirox from a topical antifungal agent to a promising virulence-modifying agent agent against P. aeruginosa, a problematic Gram-negative pathogen.

• Journal of Oral Medicine and Pain
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• 제24권4호
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• pp.361-374
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• 1999

F. nucleatum is a gram-negative obligate anaerobe which is the principal and most frequent cause of gingival inflammation and is the predominant pathogen isolated in subsequent periodontal breakdown. It is also one of the most numerous bacteria found in subgingival plaque samples from healthy sites; its numbers are about 10-fold greater in plaque from periodontally diseased sites. The purpose of this study is to examine the effects of outer membrane(OM), outer membrane vesicle(OMV), and lipopolysaccharide(LPS) from F. nucleatum ATCC 25586 strain on the growth of human gingival fibroblasts and HOS 941 cells, and on the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression of mouse splenocytes. For the examination of cytotoxic effects, $TNF-{\alpha}$ production and $TNF-{\alpha}$ mRNA expression, the MTT assay, the ELISA and the RT-PCR were performed, respectively. All extracts of F. nucleatum tested were cytotoxic to both of human gingival fibroblasts and HOS 941 cells, and the significant difference of cytotoxic activity among the extracts was not observed. In the effects of these extracts on the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression of mouse splenocytes, all extracts of F. nucleatum tested also stimulated the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression, but the effects of the OM extracts on the $TNF-{\alpha}$ production / $TNF-{\alpha}$ mRNA expression were higher than those of the OMV and the LPS extracts. The pattern of the $TNF-{\alpha}$ mRNA expression was similar to that of the $TNF-{\alpha}$ production. These results indicate that F. nucleatum seems to contribute to the pathogenesis of periodontal diseases at least by its cytotoxicity, directly and its $TNF-{\alpha}$ production, indirectly.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권3호
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• pp.330-336
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• 2000

A large number of streptococci that do not fit readily into any of the established classification schemes have been relegated to a large heterogeneous group called the Streptococcus viridans, which are members of the normal flora of the mucous membranes of the body, including the oral cavity, the nasopharynx, and genitourinary tract. This group includes S. mitis, S. oralis, S. sanguis, S. salivarius, S. milleri, etc. Surveying on the literature, it has been reported that infective endocarditis, meningitis, rhabdomyolysis, cholangitis, appendicitis caused by Streptococcus viridans, which were the most important pathogen in children with malignant hematologic disease. Various antibiotics has been chosen for treatment or prophylaxis for these infections, but were generally lower antimicrobial susceptibilities because of an abuse of antibiotics and advent of resistant group. Therefore, surveillant culture must be performed to evaluate personal antimicrobial susceptibilities of intraoral microbes for proper antimicrobial choice for dental procedures. This study examined sampling from subgingival plaque of 60 chidren's microbes. The cultured bacterial isolates, Streptococcus viridans were examined 10 antimicrobial drugs with the Kirby-Bauer agar disk diffusion method. The used drugs were Penicillin, Ampicillin, Oxacillin, Cephalothin, Imipenem, Gentamicin, Erythromycin, Vancomycin, Ciprofloxacin, Clindamycin. The results were as follows : 1. Sampling Streptococcus viridans were S. mitis(65%), S. oralis(22%), S. sanguis(5%), S. intermedius(3%), S. salivarius(2%), S acidominimus(2%), Unidentified streptococcus(2%). 2. The antimicrobial susceptibility of total Streptococcus viridans : Oxacillin< Erythromycin< Pencillin=Ciprofloxacin< Cephalothin< Ampicillin< Clindamycin< Gentamicin< Imipenem=Vancomycin. 3. The antimicrobial susceptibility of S. mitis : Oxacillin=Erythromycin< Ciprofloxacin< Cephalothin< Penicillin=Ampicillin< Gentamicin< Clidamycin< Imipenem=Vancomycin. 4. The antimicrobial susceptibility of S. oralis : Oxacillin< Erythromycin< Penicillin=Ciprofloxacin=Clindamycin< Cephalothin=Gentamicin< Ampicillin< Imipenem=Vancomycin. 5. There was no significant difference in the antimicrobial susceptibility among each Streptococcus viridans group.

• 생약학회지
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• 제54권1호
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• pp.27-37
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• 2023

This research was conducted to investigate the comprehensive effects of methanol extract of Coptidis rhizoma (MECR) against oral pathogen. We studied the antibacterial, anti-biofilm, anti-gingipain and anti-inflammatory activity of MECR. The minimum bactericidal concentration (MBC) of MECR was 100 ㎍/mL against several oral pathogens. The formation of biofilm of Streptococcus mutans was reduced to 8.93~24.12% in the presence of 25 ㎍/mL of MECR. The gingipain activity of Porphyromonas gingivalis were reduced to 3.91~6.23% in case of Kgp and 5.73~7.78% in case of Rgp in the presence of 10 mg/mL of MECR. The expression of fadA mRNA, virulence factor of Fusobacterium nucleatum (F. nucleatum) was 3 folds decreased in the presence of 25 ㎍/mL of MECR. In case of YD-38 cells challenged with F. nucleatum, RQ values of IL-8 and IL-6 were reduced about 12 folds and 5.45 folds in the presence of 2 ㎍/mL of MECR. In case of RAW 264.7 murine cell challenged with F. nucleatum, RQ values of IL-1β and IL-6 were 2.52 folds and 2.55 folds reduced in the presences of 2 ㎍/mL of MECR. Conclusively, MECR showed potent antibacterial and anti-inflammatory effects against oral pathogenic bacteria.

• 치위생과학회지
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• 제15권4호
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• pp.383-392
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• 2015

치과치료를 위해 다양한 용도로 DCU에서 배출되는 물이 사용된다. 이 DCU 물의 질에 관한 계속되는 논란으로 인한 환자들의 불안감을 줄이고 양질의 치과 치료를 제공하기 위해서는 DCU 물이 음용수만큼 깨끗하게 유지되어야 한다. 따라서 본 논문은 DCU 물의 세균 오염 수준과 오염된 DCU 물의 임상적 위험성에 대하여 설명하고, 세균 오염을 방지하기 위한 여러 가지 관리 방법들을 검토하였다. 여러 국가에서 DCU 물을 대상으로 오염도를 확인하는 연구가 많이 진행되어 DCU 물이 높은 수준으로 오염되어있다는 것이 입증되었다. 오염된 DCU 물로 인해 감염된 일부 사례도 보고되었고 이는 DCU 물이 감염의 잠재적인 원인일 수 있음을 보여주었다. DCU 물로 인한 잠재적 감염의 위험성을 줄이기 위해서는 효율적인 소독방법을 사용하고 자체적인 모니터링 또한 시행되어야 한다. 하지만 제안되고 있는 여러 가지 수관관리 소독방법으로 인해 치과종사자들의 혼란이 야기되고 있으며, 효율적인 소독방법을 보편화하기 위해서는 관련 연구가 더 진행되어야 할 것으로 생각된다. 치과치료를 받는 환자들을 안심시킬 수 있는 좋은 치과서비스를 제공하기 위해서는 정책적인 개선과 국내 치과 상황에 맞는 수관 관리 지침이 빠른 시일 내에 시행되어야 할 것으로 생각된다.

• Journal of Microbiology and Biotechnology
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• 제31권5호
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• pp.705-709
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• 2021

Porphyromonas gingivalis (P. gingivalis) is a major bacterial pathogen that causes periodontitis, a chronic inflammatory disease of tissues around the teeth. Periodontitis is known to be related to other diseases, such as oral cancer, Alzheimer's disease, and rheumatism. Thus, a precise and sensitive test to detect P. gingivalis is necessary for the early diagnosis of periodontitis. The objective of this study was to optimize a rapid visual detection system for P. gingivalis. First, we performed a visual membrane immunoassay using 3,3',5,5'-tetramethylbenzidine (TMB; blue) and coating and detection antibodies that could bind to the host laboratory strain, ATCC 33277. Antibodies against the P. gingivalis surface adhesion molecules RgpB (arginine proteinase) and Kgp (lysine proteinase) were determined to be the most specific coating and detection antibodies, respectively. Using these two selected antibodies, the streptavidin-horseradish peroxidase (HRP) reaction was performed using a nitrocellulose membrane and visualized with a detection range of 10³-10⁵ bacterial cells/ml following incubation for 15 min. These selected conditions were applied to test other oral bacteria, and the results showed that P. gingivalis could be detected without cross-reactivity to other bacteria, including Streptococcus mutans and Escherichia fergusonii. Furthermore, three clinical strains of P. gingivalis, KCOM 2880, KCOM 2803, and KCOM 3190, were also recognized using this optimized enzyme immunoassay (EIA) system. To conclude, we established optimized conditions for P. gingivalis detection with specificity, accuracy, and sensitivity. These results could be utilized to manufacture economical and rapid detection kits for P. gingivalis.

• 대한치과교정학회지
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• 제52권4호
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• pp.278-286
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• 2022

Objective: To evaluate differences in the adhesion levels of the most common oral pathogens, Streptococcus mutans and Porphyromonas gingivalis, in human saliva-derived microcosm biofilms with respect to time and raw materials of orthodontic brackets. Methods: The samples were classified into three groups of bracket materials: 1) monocrystalline alumina ceramic (CR), 2) stainless steel metal (SS), and 3) polycarbonate plastic (PL), and a hydroxyapatite (HA) group was used to mimic the enamel surface. Saliva was collected from a healthy donor, and saliva-derived biofilms were grown on each sample. A real-time polymerase chain reaction was performed to quantitatively evaluate differences in the attachment levels of total bacteria, S. mutans and P. gingivalis at days 1 and 4. Results: Adhesion of S. mutans and P. gingivalis to CR and HA was higher than the other bracket materials (SS = PL < CR = HA). Total bacteria demonstrated higher adhesion to HA than to bracket materials, but no significant differences in adhesion were observed among the bracket materials (CR = SS = PL < HA). From days 1 to 4, the adhesion of P. gingivalis decreased, while that of S. mutans and total bacteria increased, regardless of material type. Conclusions: The higher adhesion of oral pathogens, such as S. mutans and P. gingivalis to CR suggests that the use of CR brackets possibly facilitates gingival inflammation and enamel decalcification during orthodontic treatment.

• 한국임상수의학회지
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• 제27권6호
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• pp.704-712
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• 2010

Porcine circovirus-2 (PCV2) 는 돼지에서 여러 형태의 질병과 증후군의 발생과 관련이 되어있어 현재는 PCV-associated diseases (PCVAD)로 총괄적으로 분류된다. PCVAD에 의한 높은 경제적 손실 때문에 많은 양돈장들이 PCV2의 감염을 확인하기 위하여 혈청을 검사하고 있다. 하지만, 기존의 혈액채취법은 비용이 높고 많은 인력이 소요되므로 큰 규모의 병원체 검사에는 어려움이 있었다. 이에 본 연구에서는 혈액채취법을 이용한 돈군의 PCV2 검사법에 대한 대체방법으로 돈방 단위의 구강액채취법의 유용성을 실제 농장에서 평가하였다. 세 곳의 다른 양돈 농장들에서 각각 6개의 25두 규모의 돈방들을 선정하여 생후 3, 5, 8, 12, 16주에 돈방 마다 하나의 구강액과 5개의 혈청을 채취하였다. 모든 시료들은 real-time PCR을 이용하여 PCV2 DNA를 검사하였고 IgG 또는 IgA 간접형광항체 검사법및 세 가지의 ELISA 검사법 (blocking ELISA, indirect ELISA, and IgG/IgM sandwich ELISA)을 이용하여 PCV2에 대한 항체를 검사하였다. 구강액에서 PCV2 DNA는 8주까지는 간헐적으로 검출이 되다가 16주에는 모든 돈방에서 검출이 되었으며, 모체유래 PCV2 특이 IgG는 3주부터 검출이 되었고 모든 농장에서 5-8주까지 지속이 되었다. 16주에는 한 농장 (Site 1)의 모든 돈방에서 감염에 의한 IgG와 IgA가 검출되었다. 혈청에서의 PCV2 DNA와 PCV2 항체의 검출은 구강액에서의 검출과 높은 상관관계를 보였다. 따라서 구강액은 돈군의 PCV2 감염을 모니터링 하기 위해 혈청대신 사용할 수 있는 저비용, 고효율의 시료가 될 수 있을 것으로 사료된다.

• 생명과학회지
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• 제31권12호
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• pp.1072-1078
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• 2021

구강 병원체 Streptococcus mutans는 인간 충치를 일으키는 주요한 원인균 중 하나로 알려져 있다. 효과적인 구강 건강관리를 위해 치약과 구강 청결제를 포함한 다양한 치과 위생 제품을 사용하고 있지만, 음식 섭취 후 구강 미생물의 재발은 빈번하게 발생한다. 본 연구는 치아우식증의 원인균인 S. mutans를 장시간 배양 시, 관찰된 급격한 세포사가 어느 시점에 유도되는지 분석하고 이러한 생장특성이 특이 대사물질의 분비와 밀접한 관련이 있는지 평가하고자 하였다. 특히, S. mutans의 생균수는 전체 72시간의 배양 중 24시간 이후에 급격히 감소한 반면, 지표균주인 대장균은 동일한 시간에 일정한 수준의 생균수를 유지하였다. 다음으로 S. mutans 배양액에 동종의 세포사를 유도하는 특정 신호물질이 포함되어 있는지를 확인하기 위해 균주의 배양 24시간 후에 배양액을 회수하였다. 비록 세포의 성장이 완전히 복구되지 않았지만, 배양액의 산성 pH를 중화하고 포도당을 보충한 조건에서 복구된 표현형이 일부 관찰되었다. 그러나 배양액의 낮은 pH의 중화만으로는 세포 생장이 전혀 회복되지 않았다. 이러한 S. mutans의 세포사는 영양소 고갈뿐만 아니라 신호전달과 밀접하게 연관될 수 있으므로 이러한 생존 표현형에 대한 이해는 S. mutans의 생물학에서 세포 간 신호전달체계에 대한 새로운 지식을 제공할 수 있다.