scholarly journals Porphyromonas gingivalis galE Is Involved in Lipopolysaccharide O-Antigen Synthesis and Biofilm Formation

2006 ◽  
Vol 74 (11) ◽  
pp. 6145-6153 ◽  
Author(s):  
Ryoma Nakao ◽  
Hidenobu Senpuku ◽  
Haruo Watanabe

ABSTRACT Porphyromonas gingivalis is a crucial component of complex plaque biofilms that form in the oral cavity, resulting in the progression of periodontal disease. To elucidate the mechanism of periodontal biofilm formation, we analyzed the involvement of several genes related to the synthesis of polysaccharides in P. gingivalis. Gene knockout P. gingivalis mutants were constructed by insertion of an ermF-ermAM cassette; among these mutants, the galE mutant showed some characteristic phenotypes involved in the loss of GalE activity. As expected, the galE mutant accumulated intracellular carbohydrates in the presence of 0.1% galactose and did not grow in the presence of galactose at a concentration greater than 1%, in contrast to the parental strain. Lipopolysaccharide (LPS) analysis indicated that the length of the O-antigen chain of the galE mutant was shorter than that of the wild type. It was also demonstrated that biofilms generated by the galE mutant had an intensity 4.5-fold greater than those of the wild type. Further, the galE mutant was found to be significantly susceptible to some antibiotics in comparison with the wild type. In addition, complementation of the galE mutation led to a partial recovery of the parental phenotypes. We concluded that the galE gene plays a pivotal role in the modification of LPS O antigen and biofilm formation in P. gingivalis and considered that our findings of a relationship between the function of the P. gingivalis galE gene and virulence phenotypes such as biofilm formation may provide clues for understanding the mechanism of pathogenicity in periodontal disease.

2011 ◽  
Vol 80 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Chen Li ◽  
Kurniyati ◽  
Bo Hu ◽  
Jiang Bian ◽  
Jianlan Sun ◽  
...  

ABSTRACTThe oral bacteriumPorphyromonas gingivalisis a key etiological agent of human periodontitis, a prevalent chronic disease that affects up to 80% of the adult population worldwide.P. gingivalisexhibits neuraminidase activity. However, the enzyme responsible for this activity, its biochemical features, and its role in the physiology and virulence ofP. gingivalisremain elusive. In this report, we found thatP. gingivalisencodes a neuraminidase, PG0352 (SiaPg). Transcriptional analysis showed thatPG0352is monocistronic and is regulated by a sigma70-like promoter. Biochemical analyses demonstrated that SiaPgis an exo-α-neuraminidase that cleaves glycosidic-linked sialic acids. Cryoelectron microscopy and tomography analyses revealed that thePG0352deletion mutant (ΔPG352) failed to produce an intact capsule layer. Compared to the wild type,in vitrostudies showed that ΔPG352 formed less biofilm and was less resistant to killing by the host complement.In vivostudies showed that while the wild type caused a spreading type of infection that affected multiple organs and all infected mice were killed, ΔPG352 only caused localized infection and all animals survived. Taken together, these results demonstrate that SiaPgis an important virulence factor that contributes to the biofilm formation, capsule biosynthesis, and pathogenicity ofP. gingivalis, and it can potentially serve as a new target for developing therapeutic agents againstP. gingivalisinfection.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Masaaki Minami ◽  
Hiroshi Takase ◽  
Mineo Nakamura ◽  
Toshiaki Makino

Porphyromonas gingivalis is an important pathogenic anaerobic bacterium that causes aspiration pneumonia. This bacterium frequently forms biofilms in the oral cavity and in respiratory tract-associated medical devices. Bacterial colonization that occurs in association with this biofilm formation is the main reason for incurable aspiration pneumonia. The Lonicera caerulea var. emphyllocalyx (LCE) fruit has been used in folk medicine in Hokkaido, the northern part of Japan. The aim of this study was to elucidate one of the antimicrobial mechanisms of LCE methanol extract (LCEE)—the inhibitory effect of LCEE on biofilm formation by P. gingivalis. Our results show that LCEE significantly reduced biofilm formation by three different P. gingivalis isolates in a concentration- and time-dependent manner that were quantified by the adsorption of safranin red. When LCEE was added to biofilms already formed by P. gingivalis, LCEE did not degrade the biofilm. However, treatment with LCEE significantly promoted the removal of existing biofilm by vibration compared to that of control. We also confirmed biofilm formation in LCEE-treated P. gingivalis in tracheal tubes using scanning electron microscopic (SEM) analysis. Cyanidin 3-O-glucoside (C3G), one of the components of LCE, also inhibited the formation of biofilm by P. gingivalis in a concentration-dependent manner. Our results reveal that LCEE may be an effective antibacterial substance for P. gingivalis-induced aspiration pneumonia because of its role in the suppression of bacterial biofilm formation in the oral cavity.


2018 ◽  
Vol 200 (11) ◽  
pp. e00790-17 ◽  
Author(s):  
Christopher J. Rocco ◽  
Lauren O. Bakaletz ◽  
Steven D. Goodman

ABSTRACTThe oral cavity is home to a wide variety of bacterial species, both commensal, such as various streptococcal species, and pathogenic, such asPorphyromonas gingivalis, one of the main etiological agents of periodontal disease. Our understanding of how these bacteria ultimately cause disease is highly dependent upon understanding how they coexist and interact with one another in biofilm communities and the mechanisms by which biofilms are formed. Our research has demonstrated that the DNABII family of DNA-binding proteins are important components of the extracellular DNA (eDNA)-dependent matrix of bacterial biofilms and that sequestering these proteins via protein-specific antibodies results in the collapse of the biofilm structure and release of the resident bacteria. While the high degree of similarity among the DNABII family of proteins has allowed antibodies derived against specific DNABII proteins to disrupt biofilms formed by a wide range of bacterial pathogens, the DNABII proteins ofP. gingivalishave proven to be antigenically distinct, allowing us to determine if we can use anti-P. gingivalisHUβ antibodies to specifically target this species for removal from a mixed-species biofilm. Importantly, despite forming homotypic biofilmsin vitro,P. gingivalismust enter preexisting biofilmsin vivoin order to persist within the oral cavity. The data presented here indicate that antibodies derived against theP. gingivalisDNABII protein, HUβ, reduce by half the amount ofP. gingivalisorganisms entering into preexisting biofilm formed by four oral streptococcal species. These results support our efforts to develop methods for preventing and treating periodontal disease.IMPORTANCEPeriodontitis is one of the most prevalent chronic infections, affecting 40 to 50% of the population of the United States. The root cause of periodontitis is the presence of bacterial biofilms within the gingival space, withPorphyromonas gingivalisbeing strongly associated with the development of the disease. Periodontitis also increases the risk of secondary conditions and infections such as atherosclerosis and infective endocarditis caused by oral streptococci. To induce periodontitis,P. gingivalisneeds to incorporate into preformed biofilms, with oral streptococci being important binding partners. Our research demonstrates that targeting DNABII proteins with an antibody disperses oral streptococcus biofilm and preventsP. gingivalisentry into oral streptococcus biofilm. These results suggest potential therapeutic treatments for endocarditis caused by streptococci as well as periodontitis.


2017 ◽  
Vol 50 (2) ◽  
pp. 55
Author(s):  
Zulfan M. Alibasyah ◽  
Ambrosius Purba ◽  
Budi Setiabudiawan ◽  
Hendra Dian Adhita ◽  
Dikdik Kurnia ◽  
...  

Background: Porphyromonas gingivalis (P. gingivalis) is a pathogenic bacteria present in the oral cavity involved in the pathogenesis of chronic periodontitis and biofilm. This mass of microorganisms represents one of the virulent factors of P. gingivalis which plays an important role as an attachment initiator in host cells. Sarang semut is a natural material possessing the ability to inhibit the growth of P. gingivalis. Purpose: This study aims to analyze the effect of sarang semut extract on the formation of P. gingivalis biofilm. Methods: The study used methanol sarang semut extract and P. gingivalis ATCC 33277 and phosphomycin as a positive control. Treatment was initiated by means of culturing. Biofilm test and P. gingivalis biofilm formation observation were subsequently performed by means of a light microscope at a magnification of 400x. Results: The formation of P. gingivalis biofilms tended to increase at 3, 6, and 9 hours. Results of the violet crystal test showed that concentrations of 100% and 75% of the sarang semut extract successfully inhibited the formation of P. gingivalis biofilm according to the incubation time. Meanwhile, the sarang semut extracts at concentrations of 50%, 25%, 12.5%, and 6.125% resulted in weak inhibition of the formation of P. gingivalis biofilm. The biofilm mass profile observed by a microscope tended to decrease as an indicator of the effects of the sarang semut extract. Conclusion: Sarang semut extract can inhibit the formation of P. gingivalis biofilm, especially at concentrations of 100% and 75%. Nevertheless, phosphomycin has stronger antibiofilm of P. gingivalis effects than those of the sarang semut extract at all of the concentrations listed above.


2006 ◽  
Vol 188 (15) ◽  
pp. 5510-5523 ◽  
Author(s):  
Mary E. Davey ◽  
Margaret J. Duncan

ABSTRACT Periodontitis is a biofilm-mediated disease. Porphyromonas gingivalis is an obligate anaerobe consistently associated with severe manifestations of this disease. As an opportunistic pathogen, the ability to proliferate within and disseminate from subgingival biofilm (plaque) is central to its virulence. Here, we report the isolation of a P. gingivalis transposon insertion mutant altered in biofilm development and the reconstruction and characterization of this mutation in three different wild-type strains. The mutation responsible for the altered biofilm phenotype was in a gene with high sequence similarity (∼61%) to a glycosyltransferase gene. The gene is located in a region of the chromosome that includes up to 16 genes predicted to be involved in the synthesis and transport of capsular polysaccharide. The phenotype of the reconstructed mutation in all three wild-type backgrounds is that of enhanced biofilm formation. In addition, in strain W83, a strain that is encapsulated, the glycosyltransferase mutation resulted in a loss of capsule. Further experiments showed that the W83 mutant strain was more hydrophobic and exhibited increased autoaggregation. Our results indicate that we have identified a gene involved in capsular-polysaccharide synthesis in P. gingivalis and that the production of capsule prevented attachment and the initiation of in vitro biofilm formation on polystyrene microtiter plates.


2017 ◽  
Vol 45 (1) ◽  
pp. 4
Author(s):  
Andresa De Cássia Martini ◽  
Lianna Ghisi Gomes ◽  
Letícia Camara Pitchenin ◽  
Fábio Dumit Pizzinatto ◽  
Dábila De Araújo Sônego ◽  
...  

Background: Periodontal disease (PD) is the most common disease of the oral cavity in cats and dogs, and it affects up to 80% of these animals. PD begins with the accumulation of bacteria on the surface of the teeth, and it poses a risk for the health of pets. Research on PD in dogs has focused on the identification and characterization of bacterial communities present in the oral cavity. Porphyromonas gingivalis is highly prevalent in the oral cavity. Therefore, the aim of this study was to detect P. gingivalis before and after dental eruption in 15 English bulldog newborn puppies, hoping to contribute to early guidance of oral hygiene management and prevent future PD.Materials, Methods & Results: Fifteen English bulldog newborn puppies were used in this study. Two groups (G1 and G2) were formed with eight and seven puppies, respectively. Oral swab samples were taken from the maxillary incisor region of animals from G1 and G2 10 days after birth (T10). At this moment, the clinical evaluation of the oral cavity showed healthy gums with a thin, shiny, pinkish, and firm margin, without any odor or granular appearance, and with no tooth eruption. On postnatal day 25 (T25), a subgingival sample was collected with a Gracey curette from the maxillary incisors; the oral cavity examination revealed healthy gums and presence of gingival sulcus. Bilateral subgingival samples were also collected from the maxillary canines and fourth premolars of the dams at T10 and T25. All newborn puppies were fed maternal breast milk and supplementation exclusively with commercial milk for dogs in individual bottles. The dams were fed commercial dry food. The average weight of G1 and G2 at T10 was 625.87 ± 85.26 g and 543.50 ± 92.88 g, respectively, and 100% (15/15) of the animals were negative for PG as assessed by polymerase chain reaction (PCR) on oral swab samples. At T25, puppies from groups G1 and G2 weighed 1.465 ± 194 g and 1.206 ± 201 g, respectively, and 100% (15/15) of the puppies were positive for P. gingivalis as assessed by PCR on subgingival samples collected with a Gracey curette. The dams of the puppies in G1 and G2 were positive for PG at T10 and T25 as determined by PCR on subgingival samples.Discussion:An important finding of this study was that the dams of the puppies in G1 and G2 were positive for P. gingivalis at T10. Several species of bacteria that cause periodontal disease can be transmitted from humans to pets; therefore, transmission from dam to puppy would be possible, but was not observed in this study at T10, when 100% (15/15) of the animals were negative for P. gingivalis. Subgingival microbiota associated with periodontitis consists essentially of Porphyromonas spp., and the presence of gingival sulcus and dental eruption are determinant factors for the presence of P. gingivalis in the oral cavity. Nevertheless, the hygiene habits of dogs, with the dam licking the puppies after dental eruption, could have been a relevant factor for transmission and appearance of P. gingivalis in the subgingival sample in 100% (15/15) of the puppies at T25. The oral microbiota is closely related to many diseases, and resident pathogenic oral bacteria can be transferred by close contact. Certain species of bacteria present in the subgingival biofilm exhibit higher etiologic relevance during the onset and progression of periodontitis, and Porphyromonas spp. is among the most important of these species. It is important to keep in mind that age is a relevant factor to prevent periodontitis. Therefore, providing owners with instructions for thorough dental brushing of animals when they still have deciduous teeth can prevent the appearance of future PD.


Author(s):  
Assadawy M ◽  
Helmy E

Introduction: Biofilm formation on implants is the primary factor for implant loss. Porphyromonas gingivalis is a highly virulent pathogen that contributes to the development of periodontal disease and implant failure.


2015 ◽  
Vol 84 (1) ◽  
pp. 127-137 ◽  
Author(s):  
S. Hathroubi ◽  
M. A. Hancock ◽  
J. T. Bossé ◽  
P. R. Langford ◽  
Y. D. N. Tremblay ◽  
...  

Actinobacillus pleuropneumoniaeis a Gram-negative bacterium belonging to thePasteurellaceaefamily and the causative agent of porcine pleuropneumonia, a highly contagious lung disease causing important economic losses. Surface polysaccharides, including lipopolysaccharides (LPS) and capsular polysaccharides (CPS), are implicated in the adhesion and virulence ofA. pleuropneumoniae, but their role in biofilm formation is still unclear. In this study, we investigated the requirement for these surface polysaccharides in biofilm formation byA. pleuropneumoniaeserotype 1. Well-characterized mutants were used: an O-antigen LPS mutant, a truncated core LPS mutant with an intact O antigen, a capsule mutant, and a poly-N-acetylglucosamine (PGA) mutant. We compared the amount of biofilm produced by the parental strain and the isogenic mutants using static and dynamic systems. Compared to the findings for the biofilm of the parental or other strains, the biofilm of the O antigen and the PGA mutants was dramatically reduced, and it had less cell-associated PGA. Real-time PCR analyses revealed a significant reduction in the level ofpgaA,cpxR, andcpxAmRNA in the biofilm cells of the O-antigen mutant compared to that in the biofilm cells of the parental strain. Specific binding between PGA and LPS was consistently detected by surface plasmon resonance, but the lack of O antigen did not abolish these interactions. In conclusion, the absence of the O antigen reduces the ability ofA. pleuropneumoniaeto form a biofilm, and this is associated with the reduced expression and production of PGA.


2006 ◽  
Vol 74 (10) ◽  
pp. 5756-5762 ◽  
Author(s):  
Carlo Amorin Daep ◽  
DeAnna M. James ◽  
Richard J. Lamont ◽  
Donald R. Demuth

ABSTRACT Porphyromonas gingivalis is a periodontal pathogen whose primary niche is the anaerobic environment of subgingival dental plaque, but initial colonization of the oral cavity is likely to occur on supragingival surfaces that already support robust biofilm communities. Our studies have shown that P. gingivalis adheres to Streptococcus gordonii through interaction of the minor fimbrial antigen Mfa1 with a specific region of the streptococcal SspB polypeptide (residues 1167 to 1193) designated BAR. We show that a synthetic peptide comprising the BAR sequence potently inhibits P. gingivalis adherence to S. gordonii (50% inhibitory concentration = 1.3 μM) and prevents the development of P. gingivalis biofilms. However, a retroinverso peptide that possessed the same side chain topology as that of BAR was inactive, suggesting that interactions of Mfa1 with the peptide backbone of BAR are important for binding. A conformationally constrained analog of BAR inhibited P. gingivalis adherence and biofilm formation but at a lower specific activity than that of BAR. Therefore, to further define the structural features of the Mfa1-BAR interaction, we functionally screened combinatorial libraries of BAR in which active site residues (Asn1182, Thr1184, and Val1185) were replaced with each of the 19 common amino acids. Peptides containing positively charged amino acids at position 1182 or hydrophobic residues at position 1185 bound P. gingivalis more efficiently than did control peptides containing Asn and Val at these positions, suggesting that electrostatic and hydrophobic interactions may contribute to Mfa1-SspB binding. In contrast, replacement of Pro or Gly at these positions was detrimental to adherence, suggesting that perturbation of the BAR secondary structure influences activity. The net effect of substitutions for Thr1184 was less pronounced either positively or negatively than that at the other sites. These results define physicochemical characteristics of the interacting interface of Mfa1 and SspB and suggest that peptides or peptidomimetics with greater specific inhibitory activity than that of BAR can be developed. These compounds may represent potential therapeutics that target some of the first molecular interactions that allow P. gingivalis to colonize the oral cavity.


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