• International Journal of Oral Biology
• /
• 제33권4호
• /
• pp.149-154
• /
• 2008

Porphyromonas gingivalis, a major periodontal pathogen, has been implicated in the initiation and progression of periodontal disease. Endothelial dysfunction (Editor note: Aberrant and dysfunction are somewhat redundant. The authors may want to choose one or the other.) contributes to chronic periodontal inflammation. Using cDNA-representational difference analysis, we found that P.gingivalis lipopolysaccharide differentially induces a number of genes in human microvascular endothelial cells. Among these upregulated genes, we focused on intercellular adhesion molecule-1 (VCAM-1), which is crucial for leukocyte recruitment during vascular inflammation. P. gingivalis LPS significantly increased the expression of vascular cell adhesion molecule-1 (VCAM-1) as well as ICAM-1. Promoter assays revealed that the transcription of these cell adhesion molecules was mainly regulated by nuclear factor-${\kappa}B$ (NF-${\kappa}B$) in endothelial cells. Furthermore, P. gingivalis LPS significantly increased leukocyte adhesiveness to microvascular endothelial cells and to aortic endothelium. Taken together, our results demonstrate that P. gingivalis LPS activates microvascular endothelial cells through NF-${\kappa}B$-dependent expression of cell adhesion molecules.

• 한국미생물·생명공학회지
• /
• 제38권2호
• /
• pp.117-123
• /
• 2010

BT toxin is produced by a soil bacterium Bacillus thuringiensis and has long been used as a biological insecticide without any competition. Recently, Photorhabdus, a symbiotic bacterium from entomopathogenic nematodes, family Heterorhabditae, has been researched and discussed as alternatives to B. thuringiensis. Photorhabdus, which lives in the gut of entomopathogenic nematodes, is a highly virulent pathogen of a wide range of insect larvae. When an insect is infected by the nematodes, the bacteria are released into the cadaver, and produce a number of insecticidal toxins. The biological role of the different Photorhabdus toxins in the infection process is still unclear. Photorhabdus toxin complex (Tc) is highly secreted gut-active toxin and has been characterized as a potent three-component (A, B and C) insecticidal protein complex. These components are necessary for full oral activity against insect larvae. The Photorhabdus PirAB binary toxins exhibit a potent injectable activity for Galleria mellonella larvae, and have oral toxicity against mosquitoes and caterpillar pest Plutella xylostella. Other toxin, 'makes caterpillars floppy' (Mcf) showed injectable activity on caterpillars. Recombinant Mcf triggers apoptosis in both insect hemocytes and the midgut epithelium and carries a BH3 domain. In this review, the relationship between the Photorhabdus and the nematode is discussed and recent important insecticidal toxins from Photorhabdus are described.

• International Journal of Oral Biology
• /
• 제46권3호
• /
• pp.127-133
• /
• 2021

We previously showed that γ-glutamyltranspeptidase (GGT), an enzyme involved in glutathione metabolism, in Bacillus subtilis acts as a virulence factor for osteoclastogenesis via the RANKL-dependent pathway. Hence, it can be hypothesized that GGT of periodontopathic bacteria acts as a virulence factor in bone destruction. Because Fusobacterium nucleatum, which is a periodontopathic pathogen, has GGT with a primary structure similar to that of B. subtilis GGT (37.7% identify), the bone-resorbing activity of F. nucleatum GGT was examined here. Recombinant GGT (rGGT) of F. nucleatum was expressed in Escherichia coli and purified using the His tag of rGGT. F. nucleatum rGGT (Fn rGGT) was expressed as a precursor of GGT, and then processed to a heavy subunit and a light subunit, which is characteristic of general GGTs, including the human and B. subtilis enzymes. Osteoclastogenesis was achieved in a co-culture system of mouse calvaria-derived osteoblasts and bone marrow cells. Fn rGGT induced osteoclastogenesis to a level similar to that of B. subtilis rGGT; furthermore, osteoclastogenesis was induced in a dose-dependent manner. These results suggest that F. nucleatum GGT possesses a virulent bone-resorbing activity, which could play an important role in the pathogenesis of periodontitis.

• International Journal of Oral Biology
• /
• 제46권3호
• /
• pp.99-104
• /
• 2021

Associations between periodontal infection and cardiovascular disease have been documented. Porphyromonas gingivalis is a well-established periodontal pathogen, and tissue factor (TF) is a key initiator of the coagulation cascade. In this context, P. gingivalis has been reported to enhance TF expression in human endothelial cells. The present study investigated the underlying mechanisms of TF induction by P. gingivalis in human umbilical vein endothelial cells. P. gingivalis increased TF expression in a dose- and time-dependent manner. Not only live bacteria but also glutaraldehyde-fixed bacteria increased TF expression to the same extent. However, sonicates of P. gingivalis did not induce TF expression. Cytochalasin D and SMIFH2, which are inhibitors of actin polymerization and actin nucleation, respectively, inhibited the TF expression induced by P. gingivalis. Finally, TF production was decreased or increased in the presence of various signaling inhibitors, including mitogen-activated protein kinases. These results suggest that P. gingivalis induces endothelial TF expression by a bacterial internalization-dependent mechanism and through diverse signal transduction mechanisms.

• 한국동물위생학회지
• /
• 제43권4호
• /
• pp.245-250
• /
• 2020

Infectious bovine keratoconjunctivitis (IBK) is the most common ocular disease in cattle, manifesting as corneal opacity, corneal ulcerations and potentially vision loss. The present report describes a 10-month-old Holstein Friesian heifer with IBK treated by systemic tulathromycin, and subconjunctival injection of penicillin and dexamethasone. We investigated changes in the hematological indices and microorganisms related to IBK after treatment. Neutrophils and monocytes decreased during recovery, so it was assumed that these two types of white cells are associated with IBK. Moraxella bovoculi was cleared in the eye, nasal cavity, and oral cavity after treatment. The distribution of M. bovoculi before treatment indicated that a combined systemic and subconjunctival treatment was necessary. The lesioned eye was found to be overwhelmed by Mycoplasma bovoculi, while pathogen abundance was reduced in the nasal cavity and oral cavities. These results suggest that antibiotic treatment can alter the composition and relative abundance of microorganisms.

• 한국미생물·생명공학회지
• /
• 제27권5호
• /
• pp.419-425
• /
• 1999

Prophylactic effects of Bifidobacterium longum HY8001, Korean isolate, against Escherichia coli O157:H7 and Salmonella typhimurium DT104 enteric infection were examined at four groups of specific pathogen free(SPF)-ICR mouse for each pathogen. B. longum HY8001+B. typhimurium DT104+B. longum HY8001(BL+ST+BL) group and B. longum HY8001+E. coli O157:H7+B. longum HY8001(BL+E+BL) group were fed with B. longum HY8001 before and after E. coli O157:H7 or s. typhimurium DT104 challenge, while B. longum HY8001+S. typhimurium DT104(BL+ST) and B. longum HY8001+e. coli O157:H7(BL+E) groups were fed with B. longum HY8001 only before E. coli O157:H7 or S. typhimurium DT104 challenge. E. coli O157:H7(E) and S. typhimurium DT104(ST) groups were challenged with each pathogen without B. longum HY8001 administration and control groups were administered with phosphate buffered solution(PBS). After the oral administration with B. longum HY8001(109cfu), th emice were challenged with E. coli O157:H7(2$\times$1010cfu) or S. typhimurium DT104(108cfu) and the mortality rate and the fecal shedding of challenged pathogen were also examined define the reactivity of the B. longum HY8001. Production of toxin neutralizing substance(s) of B. longum HY8001 was determined by cell cytotoxicity assay using Vero cells. Fecal shedding of th eS. typhimurium DT104 was significantly decreased in BL+ST+BL group fed with B. longum HY8--1 before and after challenge(p<0.05), while the fecal shedding s of S. typhimurium DT104 in BL+ST and St groups remained more than 106cfu. the protective effect of the B. longum HY8001 against E. coli O157:H7 was significantly high only in BL+E+BL group fed with b. longum Hy8001 before and after E. coli O157:H7 challenge from the result of fecal E. coli O157:H7 isolation rate, mortality rate, and intestinal contents culture to detect E. coli O157:H7. the mortality rate of the BL+e and E groups. The cytopathic effect (CPE) of the Vero cytotoxin (Shiga like toxin I & II) in Vero cell was neutralized in B. longum HY8001 culture supernatant added wells which indicate the presence of soluble Vero cytotxin neutralizing substance(s) in B. longum HY8001 culture suprnatant.

• Journal of Oral Medicine and Pain
• /
• 제35권1호
• /
• pp.19-29
• /
• 2010

나무가 갖는 특유의 향인 피톤치드는 휘발성 화학물질로서, 식물이 방어를 위해 스스로 생성하여 발산하는 물질이며, 항균, 방충, 소취 등 다양한 기능을 가지고 있는 천연 물질이다. 편백나무(Chamaecyparis obtusa Sieb. et Zucc.; Japanese cypress)에서 추출한 피톤치드 정유가 구강 내 상주균주이면서 구강 캔디다증을 일으키는 Candida albicans에 미치는 효과를 알아보기 위해 편백 피톤치드와 함께 C. albicans 를 배양한 후, 성장정도, 생존력 및 형태적 변화를 관찰한 결과, 피톤치드는 C. albicans에 강한 항진균력을 보였고, C. albicans에 대한 피톤치드의 최소억제농도(MIC)는 0.25%, 최소살균농도(MFC)는 0.5%였으며, 성장 곡선 상에서, MIC에 근접한 농도의 피톤치드는 C. albicans의 성장을 억제하였다. 피톤치드를 첨가하여 배양한 C. albicans는 투과전자현미경 상에서, MIC 농도에서 대다수의 세포가 세포질 내 전자밀도가 높은 과립물질과 공포를 보이는 비전형적인 형태를 보였다. 이상의 결과로, 피톤치드는 C. albicans에 대해 살균작용에 의한 항진균효과를 갖고 있는 것으로 판단된다. 따라서, 피톤치드의 항진균력은 구강 내 상주균주이면서 특별한 경우에 구강 캔디다증을 일으키는 C. albicans에 유효하게 작용하며, 이를 이용한 구강 위생용품의 적용으로 구강 캔디다증의 예방과 치료 및 예후관리에도 매우 유용하게 사용되리라고 생각된다.

• 한국치위생학회지
• /
• 제17권1호
• /
• pp.13-25
• /
• 2017

Objectives: The purpose of this study was to compare colony forming unit (CFU) method and multiplex real-time polymerase chain reaction (MRT-PCR) method for accurate quantitative analysis of bacteria. Methods: We compared the CFU method and the MRT-PCR method, which are still used in Korea, for Prevotella intermedius (P. intermedius), a periodontal disease pathogen selected by MRT-PCR, and Streptococcus mutans (S. mutans), a dental caries causative organism. The subjects of this study were 30 patients who visited the C dental hospital. Results: Total microorganisms in MRT-PCR method were significantly higher in both types of bacteria (p<0.05), since DNA of dead bacteria was also analyzed. This was because the periodontal dise(-) anaerobes, and even dead bacteria contain large amounts of toxic substances called LPS in the extracellular membrane, and fimbriae and pili, which are motility structures, still remain as a strong toxic substance in periodontal tissue. Conclusions: Therefore, in terms of the total amount of bacteria found, the MRT-PCR method will be a useful technique for searching all the bacteria in the oral cavity including live bacteria, as well as sterilization.

• Molecules and Cells
• /
• 제27권2호
• /
• pp.257-261
• /
• 2009

Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) is an important pathogen casuing aggressive periodontitis. The present study was designed to investigate the chemokines expression regulated by A. actinomycetemcomitans lipopolysaccharide (LPS). Chemokines genes expression profiling was performed in Raw 264.7 cells by analyses of microarray and reverse transcription-polymerase chain reaction (RT-PCR). Microarray results showed that the induction of monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-$1{\alpha}$ (MIP-$1{\alpha}$), MIP-$1{\beta}$, MIP-$1{\gamma}$, regulated upon activation, normal T-cell expressed and secreted (RANTES), macrophage inflammatory protein-2 (MIP-2), and interferon-${\gamma}$ inducible protein 10 (IP 10) by A. actinomycetemcomitans LPS was increased to 12.5, 1.53, 9.09, 17.3, 2.82, 16.1, and 18.1 folds at 18 h, respectively. To check these chemokines expression by A. actinomycetemcomitans LPS, we examined gene expressions by RT-PCR, and found that the expression of MIP-$1{\beta}$, MIP-$1{\gamma}$, RANTES, MIP-2, and IP 10 was increased 107.1, 93.6, 106.8, 86.5, and 162.0 folds at 18 h, respectively. These results indicate that A. actinomycetemcomitans LPS stimulates the several chemokines expressions (MIP-$1{\alpha}$, MIP-$1{\beta}$, MIP-$1{\gamma}$, RANTES, MIP-2, and IP 10) in Raw 264.7 cells.

• Journal of Microbiology and Biotechnology
• /
• 제7권6호
• /
• pp.423-428
• /
• 1997

Vibrio vulnificus is a halophilic gram-negative human pathogen, which affects people with underlying liver diseases or a suppressed immune system, often leading to primary septicemia with a mortality rate of higher than 60%. In an effort to develop an oral vaccine against V. vulnificus infection, we prepared a whole cell killed vaccine of V. vulnificus on a large scale and compared the immunogenicity and protective efficacy of the vaccine administered in three formulation forms in rabbits. Since V. vulnificus O-antigen serotypes 1, 2, 3, 4, 5, and 7 account for more than 95% of clinical isolates, we prepared cell lysates from these six serotype strains and mixed in equal amounts for a vaccine. The vaccine was administered to rabbits intramuscularly (i.m.), orally as granules or as enteric-coated granules. In rabbits, all three formulation forms elicited a high level of serum IgG antibody reactive not only to the six strains but also to other O-antigen serotypes 6, 8 and 9, indicating cross-reactivities among the strains. Immunotherapeutic efficacy of the antisera was also evaluated by a passive immunization assay, which revealed that the orally immunized antisera as well as the i.m. immunized antisera was protective against a subsequent lethal challenge of V. vulnificus. These data demonstrate that oral immunization with a V. vulnificus whole cell lysate vaccine induced a systemic immune response and suggest the feasibility of development of this vaccine preparation as an oral vaccine.