ABSTRACT
FimA has been characterized as an important virulence factor for Porphyromonas gingivalis (Pg). These structures play a major role in the mechanisms of adhesion and invasion of Pg to host cells, and can induce cellular activation and cytokines release. FimA can also promote biofilm formation and induce immuno-inflammatory response of host cells. Many studies have characterized FimA to be associated with periodontitis and cardiovascular disease. Pg strains are classified into six types based on divergent nucleotide sequences of the fimA gene (types Ⅰ、Ⅰb、Ⅱ、Ⅲ、Ⅳ andⅤ). The expression of fimbriae is regulated by the fimA gene, which may be the key factor that leads to virulence diversities of Pg, At present, the research on the pathogenesis of FimA mainly focuses on periodontitis and atherosclerosis, which is of great significance for the prevention and treatment of diseases. This paper reviewed the pathogenic effect of FimA in the development of above mentioned two diseases and its application in the prevention.
ABSTRACT
Objective: To construct gine expression plasmid and to purify the protein of fimbriae(FimA) of Porphyromonas gingivalis (P. gingivalis). Methods: The bacteria DNA was extracted from P. gingivalis by using commercial kit. FimA gene was cloned after PCR. Plasmid was constructed and transformed into competent cells. Optimal conditions of protein induction were chosen. The fusionprotein was purified by Glutathione S-Transferase affinity chromatography. Fusion protein was confirmed by Western blot method. Results: The highest protein expression by the constructed plasmid was obtained at the low temperature and high concentration after 12 hours induction. The protein was confirmed by Western blot. Conclusion: A highly purified P. gingivalis FimA protein was successfully obtained.
ABSTRACT
La diabetes gestacional (DG) es una de las complicaciones médicas que más frecuentemente afectan a las mujeres embarazadas; algunos autores reportan una prevalencia entre el 9,7 y el 13,9%. La DG puede ser causa de efectos adversos como: nacimiento pretérmino, macrosomia, nacimiento por cesárea, hiperbilirrubinemia, hipertensión gestacional, así como la predisposición de desarrollar posteriormente diabetes mellitus tipo 2 y síndrome metabólico. La literatura señala la asociación entre los microorganismos presentes en el biofilm subgingival, etiológicos de la inflamación de los tejidos de soporte dentarios y diabetes mellitus. Uno de estos microorganismos, Porphyromonas gingivalis, expresa, entre otros factores de virulencia, una proteína llamada fimbrilina, la cual presenta variaciones genotípicas relacionadas con su capacidad de inducción en la expresión de mediadores inflamatorios; los genotipos fimA II y fimA IV se consideran con mayor capacidad de virulencia y su presencia se ha asociado con la resistencia a la insulina. En este estudio analizamos la prevalencia de los genotipos fimA II y fimA IV en un grupo de mujeres mexicanas de la región central de México con DG, en mujeres con embarazo sin diabetes y mujeres sin embarazo y sin diabetes. Los resultados encontrados muestran una elevada presencia del genotipo fimA II en mujeres con DG (p < 0,05)
Gestational diabetes (GD) is one of the most common complications in pregnant women, with some authors reporting prevalence between 9.7% and 13.9%. GD can lead to the following adverse effects: preterm birth, macrosomia, cesarean birth, hyperbilirubinemia, gestational hypertension, and predisposition to later develop diabetes mellitus type 2 and metabolic syndrome. The literature shows an association between microorganisms in the subgingival biofilm, which produces inflammation of the dental support tissue, and diabetes mellitus. Porphyromonasgingivalis is one of these microorganisms, and among other virulence factors, it expresses a protein called fimbrilin which has genotypic variations related to its ability to induce expression of inflammatory mediators. Genotypes fimA II and fimA IV are considered to have a greater virulence and their presence has been associated with insulin resistance. An analysis is made on the prevalence of genotypes fimA II and fimA IV in a group of women in central region of Mexico with GD, pregnant women without diabetes, and non-pregnant women without diabetes. The results show an elevated presence of genotype fimA II in women with GD (P <.05)
Subject(s)
Humans , Female , Pregnancy , Adult , Diabetes, Gestational , Bacteroidaceae Infections/epidemiology , Porphyromonas gingivalis , Porphyromonas gingivalis/genetics , Fimbriae Proteins/genetics , Pregnant Women , Genotype , Epidemiology, Descriptive , Prevalence , Cross-Sectional Studies , Observational Study , MexicoABSTRACT
Many Salmonella Typhimurium isolates produce type 1 fimbriae and exhibit fimbrial phase variation in vitro. Static broth culture favours the production of fimbriae, while solid agar medium inhibits the generation of these appendages. Little information is available regarding whether S. Typhimurium continues to produce type 1 fimbriae during in vivo growth. We used a type 1 fimbrial phase-variable strain S. Typhimurium LB5010 and its derivatives to infect RAW 264.7 macrophages. Following entry into macrophages, S. Typhimurium LB5010 gradually decreased the transcript levels of fimbrial subunit gene fimA, positive regulatory gene fimZ, and global regulatory gene lrp. A similar decrease in transcript levels was detected by RT-PCRwhen the pH of static brothmediumwas shifted frompH 7 to amore acidic pH 4. A fimA-deleted strain continued to multiply within macrophages as did the parental strain. An lrp deletion strain was unimpaired for in vitro growth at pH 7 or pH 4, while a strain harboring an lrp-containing plasmid exhibited impaired in vitro growth at pH 4. We propose that acidic medium, which resembles one aspect of the intracellular environment in a macrophage, inhibits type 1 fimbrial production by down-regulation of the expression of lrp, fimZ and fimA.
ABSTRACT
Fimbriae (fimA) of Porphyromonas gingivalis are filamentous components on the cell surface and are thought to play an important role in the colonization and invasion of periodontal tissue. P. gnigivalis fimA gene encoding fimbrillin, a subunit of fimbriae, has been classified into 5 genotypes (typesI to V) based on the nucleotide sequences. In the present study, we examined the prevalence of these fimA genotypes in patients with dental implant and the relationship between prevalence of these genotypes and peri-implantitis. Dental plaque specimens obtained from 80 peri-implant sulci of 50 patients with dental implants were analyzed by 16S rRNA fimA gene-directed PCR assay. P. gingivalis were detected in 74.4% of the samples of the control group (healthy peri-implant sulci; probing depth or =5mm). Among the P. gingivalis-positive samples of the control group, the most prevalent fimA type was typeI(29.3%), followed by typeII(26.8%). In contrast, a majority among the P. gingivalis-positive samples of the test group was typeII(56.5%), followed by typeI(43.5%). TypeII fimA genotype organisms were detected more frequently in the test group and a significant difference in the occurrence of typeII was observed between test and the control groups. A correlation between specific fimA types and peri-implant health status was found in typeII(OR 3.545) and only a weak relationship was revealed in typeIV(OR 3.807). These findings indicate that P. gingivalis strains that possess typeII fimA are predominant in peri-implant sulci with peri-implantitis and are closely associated with peri-implant health status. P. gingivalis with typeII fimA may be involved in peri-implantitis.
Subject(s)
Humans , Base Sequence , Colon , Dental Implants , Dental Plaque , Genotype , Peri-Implantitis , Polymerase Chain Reaction , Porphyromonas gingivalis , Porphyromonas , PrevalenceABSTRACT
Porphyromonas gingivalis is a gram negative, black-pigmented anaerobe, associated with periodontitis & peri-implantitis. Fimbriae(fimA) of P. gingivalis are filamentous components on the cell surface and important in the colonization and invasion of periodontal tissue. But all P. gnigivalis strains don't have equal pathogenicity, inequality among strains originates from different fimA genotype. P. gnigivalis fimA gene encoding fimbrillin(structural subunit of fimbriae) has been classified into 5 genotypes(typesI to V) based on the nucleotide sequences. In the present study, we examined the prevalence of these fimA genotypes in patients with dental implant and the relationship between prevalence of these genotypes and a condition of peri-implant tissue. Dental plaque specimens obtained from 189 peri-implant sulci of 97 patients with dental implants were analyzed by 16S rRNA fimA gene-directed PCR assay. P. gingivalis were detected in 86.2% of the alll samples. Among the P. gingivalis-positive samples, a significant difference in the occurrence of typeII was observed between test and the two control groups. In two control groups, typeII fimA were detected in 6.3%(PD or =5mm/BOP+), typeII fimA genotype were detected most frequently in 50.0% . And a correlation between specific fimA types and peri-implantitis was found in typeII(R(2)=1.105). These results suggest that P. gingivalis strains that possess typeII fimA are gradually increased, as a condition of peri-implant tissue is getting complicated and are closely associated with peri-implant health status. We speculate that these organisms be involved in peri-implantitis