Gingivalis Strains Research Articles

Structural and functional insights into the C-terminal signal domain of the Bacteroidetes type-IX secretion system.

Gram-negative bacteria from the Bacteroidota phylum possess a type-IX secretion system (T9SS) for protein secretion, which requires cargoes to have a C-terminal domain (CTD). Structurally analysed CTDs are from Porphyromonas gingivalis proteins RgpB, HBP35, PorU and PorZ, which share a compact immunoglobulin-like antiparallel 3+4 β-sandwich (β1-β7). This architecture is essential as a P. gingivalis strain with a single-point mutant of RgpB disrupting the interaction of the CTD with its preceding domain prevented secretion of the protein. Next, we identified the C-terminus ('motif C-t.') and the loop connecting strands β3 and β4 ('motif Lβ3β4') as conserved. We generated two strains with insertion and replacement mutants of PorU, as well as three strains with ablation and point mutants of RgpB, which revealed both motifs to be relevant for T9SS function. Furthermore, we determined the crystal structure of the CTD of mirolase, a cargo of the Tannerella forsythia T9SS, which shares the same general topology as in Porphyromonas CTDs. However, motif Lβ3β4 was not conserved. Consistently, P. gingivalis could not properly secrete a chimaeric protein with the CTD of peptidylarginine deiminase replaced with this foreign CTD. Thus, the incompatibility of the CTDs between these species prevents potential interference between their T9SSs.

Complete genome sequences of three Porphyromonas gingivalis strains, isolated from patient with esophageal squamous cell carcinoma and healthy individual in China.

Here, we report the complete genome sequences of three Porphyromonas gingivalis, one from patient with esophageal cancer (LyEC01), and the other two from periodontally healthy individuals (LyG-1 and LyG-2) in 2021 and 2023. The genome sizes of LyEC01, LyG-1, and LyG-2 were 2,408,275, 2,411,440, and 2,411,481 bp, respectively.

Porphyromonas gingivalis Strain W83 Infection Induces Liver Injury in Experimental Alcohol-Associated Liver Disease (ALD) in Mice

The liver plays a vital role in the defense against infections. Porphyromonas gingivalis (P. gingivalis), a dominant etiologic oral bacterium implicated in periodontal disease (PD), has been associated with various systemic diseases. This study aimed to investigate the influence of P. gingivalis on alcohol-associated liver diseases (ALD). Mice were fed a Lieber–DeCarli liquid diet containing 5% ethanol for 10 days after an initial adaptation period on a diet with lower ethanol content for 7 days. Two days before tissue sample collection, the mice were administered P. gingivalis strain W83 (Pg) through intraperitoneal injection (IP). Pair-fed mice with Pg infection (PF+Pg) exhibited an activated immune response to combat infections. However, alcohol-fed mice with Pg infection (AF+Pg) showed liver injury with noticeable abscess lesions and elevated serum alanine aminotransferase (ALT) levels. Additionally, these mice displayed liver infiltration of inflammatory monocytes and significant downregulation of proinflammatory cytokine gene expression levels; and AF+Pg mice also demonstrated increased intrahepatic neutrophil infiltration, as confirmed by chloroacetate esterase (CAE) staining, along with elevated gene expression levels of neutrophil cytosol factor 1 (Ncf1), neutrophilic inflammation driver lipocalin 2 (Lcn2), and complement component C5a receptor 1 (C5ar1), which are associated with neutrophilic inflammation. Interestingly, compared to PF+Pg mice, the livers of AF+Pg mice exhibited downregulation of gene expression levels of NADPH oxidase 2 (Cybb), the leukocyte adhesion molecule Cd18, and the Toll-like receptor adaptor Myd88. Consequently, impaired clearance of P. gingivalis and other bacteria in the liver, increased susceptibility to infections, and inflammation-associated hepatic necrotic cell death were observed in AF+Pg mice, which is likely to have facilitated immune cell infiltration and contributed to liver injury. Furthermore, in addition to the Srebf1/Fasn pathway induced by alcohol feeding, Pg infection also activated carbohydrate response element-binding protein (ChREBP) in AF+Pg mice. In summary, this study demonstrates that P. gingivalis infection, acting as a “second hit”, induces dysfunction of immune response and impairs the clearance of bacteria and infections in alcohol-sensitized livers. This process drives the development of liver injury.

Defining Porphyromonas gingivalis strains associated with periodontal disease

Porphyromonas gingivalis, a Gram-negative anaerobic bacterium commonly found in human subgingival plaque, is a major etiologic agent for periodontitis and has been associated with multiple systemic pathologies. Many P. gingivalis strains have been identified and different strains possess different virulence factors. Current oral microbiome approaches (16S or shotgun) have been unable to differentiate P. gingivalis strains. This study presents a new approach that aims to improve the accuracy of strain identification, using a detection method based on sequencing of the intergenic spacer region (ISR) which is variable between P. gingivalis strains. Our approach uses two-step PCR to amplify only the P. gingivalis ISR region. Samples are then sequenced with an Illumina sequencer and mapped to specific strains. Our approach was validated by examining subgingival plaque from 153 participants with and without periodontal disease. We identified the avirulent strain ATCC33277/381 as the most abundant strain across all sample types. The W83/W50 strain was significantly enriched in periodontitis, with 13% of participants harboring that strain. Overall, this approach can have significant implications not only for the diagnosis and treatment of periodontal disease but also for other diseases where P. gingivalis or its toxins have been implicated, such as Alzheimer's disease.

A pleiotropic role of sialidase in the pathogenicity of Porphyromonas gingivalis.

As one of the keystone pathogens of periodontitis, the oral bacterium Porphyromonas gingivalis produces an array of virulence factors, including a recently identified sialidase (PG0352). Our previous report involving loss-of-function studies indicated that PG0352 plays an important role in the pathophysiology of P. gingivalis. However, this report had not been corroborated by gain-of-function studies or substantiated in different P. gingivalis strains. To fill these gaps, herein we first confirm the role of PG0352 in cell surface structures (e.g., capsule) and serum resistance using P. gingivalis W83 strain through genetic complementation and then recapitulate these studies using P. gingivalis ATCC33277 strain. We further investigate the role of PG0352 and its counterpart (PGN1608) in ATCC33277 in cell growth, biofilm formation, neutrophil killing, cell invasion, and P. gingivalis-induced inflammation. Our results indicate that PG0352 and PGN1608 are implicated in P. gingivalis cell surface structures, hydrophobicity, biofilm formation, resistance to complement and neutrophil killing, and host immune responses. Possible molecular mechanisms involved are also discussed. In summary, this report underscores the importance of sialidases in the pathophysiology of P. gingivalis and opens an avenue to elucidate their underlying molecular mechanisms.

Comparative analysis of Porphyromonas gingivalis A7436 and ATCC 33277 strains reveals differences in the expression of heme acquisition systems.

Periodontitis belongs to a group of multifactorial diseases, characterized by inflammation and destruction of tooth-supporting tissues. P. gingivalis is one of the most important microbial factors involved in the initiation and progression of periodontitis. To survive in the host, the bacterium must acquire heme as a source of iron and protoporphyrin IX. P. gingivalis strains respond differently to changing iron and heme concentrations, which may be due to differences in the expression of systems involved in iron and heme acquisition. The ability to accumulate iron intracellularly, being different in more and less virulent P. gingivalis strains, may influence their phenotypes, production of virulence factors (including proteins engaged in heme acquisition), and virulence potential of this bacterium.

In-vitro polymicrobial oral biofilm model represents clinical microbial profile and disease progression during implant-related infections.

Clinically relevant in-vitro biofilm models are essential and valuable tools for mechanistically dissecting the etiopathogenesis of infectious diseases and test new antimicrobial therapies. Thus, the aim of this study was to develop and test a clinically relevant in-vitro oral polymicrobial biofilm model that mimics implant-related infections in terms of microbial profile. For this purpose, 24-well plate system was used to model oral biofilms, using three different microbial inoculums to grow in-vitro biofilms: (1) human saliva from periodontally healthy patients; (2) saliva as in inoculum 1+Porphyromonas gingivalis strain; and (3) supra and subgingival biofilm collected from peri-implant sites of patients diagnosed with peri-implantitis. Biofilms were grown to represent the dynamic transition from an aerobic to anaerobic community profile. Subsequently, biofilms were collected after each phase and evaluated for microbiological composition, microbial counts, biofilm biomass, structure, and susceptibility to chlorhexidine (CHX). Results showed higher live cell count (P<.05) for biofilms developed from patients' biofilm inoculum, but biomass volume, dry weight, and microbiological composition were similar among groups (P>.05). Interestingly, according to the checkerboard DNA-DNA hybridization results, the biofilm developed from stimulated human saliva exhibited a microbial composition more similar to the clinical subgingival biofilm of patients with peri-implantitis, with proportions of the main pathogens closer to those found in the disease. In addition, biofilm developed using saliva as inoculum was shown to be susceptible to CHX with significant reduction in bacteria compared with biofilms without exposure to CHX (P<.05). The findings suggested that the in-vitro polymicrobial biofilm developed from human saliva as inoculum is a suitable model and clinically relevant tool for mimicking the microbial composition of implant-related infections.

Corydalis saxicolaBunting total alkaloid eliminates Porphyromonas gingivalis strain 33277 internalized into macrophages by inhibition of TLR2

ObjectiveThis study aimed to investigate the impact of Corydalis Saxicola Bunting Total Alkaloid (CSBTA) on Porphyromonas gingivalis internalization within macrophages and explore the potential role of Toll-Like Receptor 2 (TLR2) in this process. MethodsWe established a P. gingivalis internalization model in macrophages by treating P. gingivalis-infected macrophages (MOI=100:1) with 200 μg/mL metronidazole and 300 μg/mL gentamicin for 1 h. Subsequently, the model was exposed to CSBTA at concentrations of 0.02 g/L or 1 μg/mL Pam3CSK4. After a 6 h treatment, cell lysis was performed with sterile water to quantify bacterial colonies. The mRNA expressions of TLR2 and interleukin-8 (IL-8) in macrophages were analyzed using RT-qPCR, while their protein levels were assessed via Western blot and ELISA respectively. ResultsP. gingivalis could internalize into macrophages and enhance the expression of TLR2 and IL-8. Activation of TLR2 by Pam3CSK4 contributed to P. gingivalis survival within macrophages and increased TLR2 and IL-8 expression. Conversely, 0.02 g/L CSBTA effectively cleared intracellular P. gingivalis, achieving a 90 % clearance rate after 6 h. Moreover, it downregulated the expression of TLR2 and IL-8 induced by P. gingivalis. However, the inhibitory effect of CSBTA on the internalized P. gingivalis model was attenuated by Pam3CSK4. ConclusionCSBTA exhibited the ability to reduce the presence of live intracellular P. gingivalis and lower IL-8 expression in macrophages, possibly by modulating TLR2 activity.

Isolation, characterization, and fibroblast uptake of bacterial extracellular vesicles from Porphyromonas gingivalis strains.

Periodontitis is an inflammatory condition caused by bacteria and represents a serious health problem worldwide as the inflammation damages the supporting tissues of the teeth and may predispose to systemic diseases. Porphyromonas gingivalis is considered a keystone periodontal pathogen that releases bacterial extracellular vesicles (bEVs) containing virulence factors, such as gingipains, that may contribute to the pathogenesis of periodontitis. This study aimed to isolate and characterize bEVs from three strains of P. gingivalis, investigate putative bEV uptake into human oral fibroblasts, and determine the gingipain activity of the bEVs. bEVs from three bacterial strains, ATCC 33277, A7A1-28, and W83, were isolated through ultrafiltration and size-exclusion chromatography. Vesicle size distribution was measured by nano-tracking analysis (NTA). Transmission electron microscopy was used for bEV visualization. Flow cytometry was used to detect bEVs and gingipain activity was measured with an enzyme assay using a substrate specific for arg-gingipain. The uptake of bEVs into oral fibroblasts was visualized using confocal microscopy. NTA showed bEV concentrations from 108 to 1011 particles/mL and bEV diameters from 42 to 356 nm. TEM pictures demonstrated vesicle-like structures. bEV-gingipains were detected both by flow cytometry and enzyme assay. Fibroblasts incubated with bEVs labeled with fluorescent dye displayed intracellular localization consistent with bEV internalization. In conclusion, bEVs from P. gingivalis were successfully isolated and characterized, and their uptake into human oral fibroblasts was documented. The bEVs displayed active gingipains demonstrating their origin from P. gingivalis and the potential role of bEVs in periodontitis.

Exploring the genetic and functional diversity of Porphyromonas gingivalis long fimbriae.

Porphyromonas gingivalis is a key pathobiont in periodontitis. Its long fimbriae consist of a single anchor (FimB), a varying number of stalk (FimA), and three accessory (tip-related) proteins (FimC, FimD, and FimE). Based on 133 strains/genomes available, it was our aim to investigate the diversity within FimA and FimB and explain the variety of long fimbriae (super-)structures. Combining the new forward primer fimAnewF with the established fimAunivR, we were able to amplify and sequence fimA including its leader region covering all genotypes and serotypes for phylogenetic analysis. We designed two primer pairs sensing the presence of an internal stop codon in fimB with an impact on fimbrial length. Finally, we examined fimbrial secondary structures by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The phylogeny of fimA/FimA revealed two new subtypes (IIa and IIb) with specific changes in functional domains and thus adding to the current classification scheme (I, Ib, and II-V). Regarding evolution, we confirm that Porphyromonas gulae fimA-type A is closely related to human P. gingivalis strains of cluster Ib and might be its ancestor genotype. A fimB internal stop codon is rare and was found in ATCC 33277 only. Comparing P. gingivalis TEM/SEM pictures of type I ATCC 33277 with type V OMI622 revealed a broad spectrum of fimbrial structures including bundling, cell-cell knotting, and brick-wall formation. In conclusion, FimA forms more distinct subtypes than previously known. The bundling of long fimbriae, a mechanism known from EPEC/EHEC and Salmonella, is proposed and supported by TEM/SEM pictures for the first time here. The role and variations of terminal accessory FimC-E in superstructure formation and/or (co-) adhesion should be investigated more closely next.

Systematic analysis of prophages carried by Porphyromonas gingivalis.

To systematically investigate the prophages carrying in Porphyromonas gingivalis (P. gingivalis) strains, analyze potential antibiotic resistance genes (ARGs) and virulence genes in these prophages. We collected 90 whole genome sequences of P. gingivalis from NCBI and utilized the Prophage Hunter online software to predict prophages; Comprehensive antibiotic research database (CARD) and virulence factors database (VFDB) were adopted to analyze the ARGs and virulence factors (VFs) carried by the prophages. Sixty-nine prophages were identified among 24/90 P. gingivalis strains, including 17 active prophages (18.9%) and 52 ambiguous prophages (57.8%). The proportion of prophages carried by each P. gingivalis genome ranged from 0.5% to 6.7%. A total of 188 antibiotic resistance genes belonging to 25 phenotypes and 46 different families with six mechanisms of antibiotic resistance were identified in the 17 active prophages. Three active prophages encoded 4 virulence genes belonging to type III and type VI secretion systems. The potential hosts of these virulence genes included Escherichia coli, Shigella sonnei, Salmonella typhi, and Klebsiella pneumoniae. In conclusion, 26.7% P. gingivalis strains carry prophages, while the proportion of prophage genes in the P. gingivalis genome is relatively low. In addition, approximately 39.7% of the P. gingivalis prophage genes have ARGs identified, mainly against streptogramin, peptides, and aminoglycosides. Only a few prophages carry virulence genes. Prophages may play an important role in the acquisition, dissemination of antibiotic resistance genes, and pathogenicity evolution in P. gingivalis.

Antimicrobial activity, viability, and physicochemical properties of an MTA-type cement with different concentrations of bismuth trioxide

Abstract In medicine, bismuth is used as an antimicrobial agent. In dentistry, it is used primarily to increase radiopacity in some endodontic materials. The objective is to evaluate the antimicrobial activity, cell viability, pH, solubility, film thickness, and setting time of a mineral trioxide aggregated (MTA)-types of cement with different concentrations of bismuth trioxide. Three experimental MTA-types of cement with a bismuth trioxide (Bi2O3) concentration of 15 wt%, 20 wt%, and 25 wt% were used. The antimicrobial activity test was conducted on Streptococcus mutans and Porphyromonas gingivalis strains. Cell viability was measured by the quantitative colorimetric assay using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide) assay on a mouse fibroblast cell line (L929). Solubility, film thickness, and setting time were performed according to ISO 6876. The lowest Bi2O3 concentrations showed the best antimicrobial activity and cell viability. pH, solubility, setting time, and film thickness did not show statistically significant differences between the different Bi2O3 concentrations tested.

A population-based study of the salivary prevalence of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans in Saudi Arabian adults with chronic periodontitis

AimsThis study was designed to investigate the incidence of subgingival Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans infections and their relationship with genetic variability in Saudi Arabian adults with chronic periodontitis and to evaluate the correlation between infection frequency and other variables. MethodsMultiplex polymerase chain reaction (PCR) assays were developed to detect P. gingivalis 16 ​S rDNA, fimbria (fimA), and collagenase (prtC) genes, as well as the A. actinomycetemcomitans 16 ​S rDNA, leukotoxin (lktA), and fimbria-associated protein (fap) genes in saliva samples from 50 patients with periodontitis and 51 healthy subjects. ResultsThe incidence of both P. gingivalis and A. actinomycetemcomitans infections was higher (72% and 14%) in the “Periodontal disease” group than in the healthy subjects (P ​< ​0.001). The P. gingivalis 16 ​S rDNA, fimA, and prtC genes were detected in 43.56%, 61.36%, and 84.09% of saliva samples, respectively, while A. actinomycetemcomitans 16 ​S rDNA, lktA, and fap genes were detected in 6.93%, 71.43%, and 0%, respectively. P. gingivalis strains with the fimA+/prtC ​+ ​genotype were found in 61.11% and 25% of chronic periodontitis patients and healthy subjects, respectively. By comparison, A. actinomycetemcomitans strains with the lktA+ ​genotype were found in 71.43% of chronic periodontitis patients. ConclusionInfection with fimA+ and prtC+ ​P. gingivalis or lktA+ ​A. actinomycetemcomitans was correlated with periodontal disease occurrence in Saudi adults. Nevertheless, A. actinomycetemcomitans lktA and P. gingivalis fimA and prtC are closely linked to periodontal destruction, whereas A. actinomycetemcomitans fap is not.

Accessory fimbrial subunits and PPAD are necessary for TLR2 activation by Porphyromonas gingivalis.

Porphyromonas gingivalis is an oral pathogen that promotes dysbiosis by quenching the bactericidal activity of the host immune system while maintaining chronic inflammation, leading to periodontitis. This involves the secretion of virulence factors such as P. gingivalis peptidyl arginine deiminase (PPAD), which converts the C-terminal Arg residues of bacterial and host-derived proteins and peptides into citrulline. We have previously shown that PPAD activity and major fimbriae (containing FimA) are necessary for P. gingivalis to activate Toll-like receptor 2 (TLR2). TLR2 is an important component of the innate immune system and plays a predominant role in the recognition of P. gingivalis by host cells. Here, we extend those findings to show that P. gingivalis strains deficient for PPAD and fimbriae induced almost identical transcriptional profiles in infected primary human gingival fibroblasts (PHGFs), but these differed substantially from the transcriptome elicited by the wild-type ATCC 33277 strain. Apparently, PPAD-modified fimbriae trigger the host cell response to P. gingivalis, as confirmed by showing that the proinflammatory host cell response mediated by TLR2 is dependent on PPAD activity and the presence of fimbriae, with type I fimbriae as the most potent TLR2 activators. We also found that PPAD-modified accessory fimbrial subunits (FimC, FimD, and FimE) alone or in combination are TLR2 ligands in a reporter cell line. Although FimA polymerization to form the fimbrial shaft was not required for TLR2 activation, the secretion and proteolytic maturation of FimA were necessary for signaling by accessory Fim proteins. This was supported by showing that the proinflammatory activation of PHGFs is dependent on PPAD and accessory fimbrial subunits. We conclude that accessory fimbrial subunits are modified by PPAD and stimulate the response to P. gingivalis infection in a TLR2-dependent manner.

Structural and antigenic characterization of a novel genotype of Mfa1 fimbriae in Porphyromonas gingivalis

ABSTRACT Background Mfa1 fimbriae of the periodontal pathogen Porphyromonas gingivalis are responsible for biofilm formation and comprise five proteins: Mfa1–5. Two major genotypes, mfa170 and mfa153, encode major fimbrillin. The mfa170 genotype is further divided into the mfa170A and mfa170B subtypes. The properties of the novel mfa170B remain unclear. Methods Fimbriae were purified from P. gingivalis strains JI-1 (mfa170A), 1439 (mfa170B), and Ando (mfa153), and their components and their structures were analyzed. Protein expression and variability in the antigenic specificity of fimbrillins were compared using Coomassie staining and western blotting using polyclonal antibodies against Mfa170A, Mfa170B, and Mfa153 proteins. Cell surface expression levels of fimbriae were analyzed by filtration enzyme-linked immunosorbent assays. Results The composition and structure of the purified Mfa1 fimbriae of 1439 was similar to that of JI-1. However, each Mfa1 protein of differential subtype/genotype was specifically detected by western blotting. Mfa170B fimbriae were expressed in several strains such as 1439, JKG9, B42, 1436, and Kyudai-3. Differential protein expression and antigenic heterogeneities were detected in Mfa2–5 between strains. Conclusion Mfa1 fimbriae from the mfa170A and mfa170B genotypes indicated an antigenic differencesuggesting the mfa170B, is to be utilized for the novel classification of P. gingivalis.

Identification of novel drug targets in Porphyromonas gingivalis and proposing inhibitors against acetate kinase using structure-based virtual screening

Porphyromonas gingivalis is the conductor of the orchestration of periodontium inflammation. Considering that a wide range of antibiotics have lost their activities in the last century, this study aimed to introduce novel and broad-spectrum drug targets against this pathogen. For this purpose, the core proteins of 17 P. gingivalis strains were obtained. Out of 1418 core proteins, 166 cytoplasmic, essential factors with no sequence similarity to host were selected. Fifty-two P. gingivalis metabolome-specific proteins were detected and then 31 novel drug targets were identified using the DrugBank database. Finally, nine broad-spectrum, novel drug targets were introduced. Acetate kinase (Ack) was selected as a novel target for drug discovery procedure due to the crucial role of this protein in the survival of P. gingivalis. Subsequently, structure-based virtual screening revealed six lead compounds with the most desirable features. Neoagarohexaose, Lucensomycin, Tetrafibricin, Naquihexcin_H, Tetramycin_A, and Platensimycin_D. Interestingly, Platensimycin_D1 had highest drug-likeness features in comparison to other lead compounds. While, Tetramycin_A and Lucensomycin showed better ADMET properties. The hit compounds identified here would be an initial compounds for experimental susceptibility testing against this pathogen. In addition, these findings might help out with the future studies on development of new therapeutic agents against P. gingivalis.

Circulating IgG antibodies to periodontal bacteria and lung cancer risk in the CLUE cohorts.

Oral health is a key indicator of overall health, well-being, and quality of life. Several studies have provided new evidence about the role of oral diseases, specifically periodontitis, in generating risk for various forms of cancers, including lung, colorectal, and pancreatic cancers. Incident lung cancer cases (n = 192) and matched controls (n = 192) were selected from participants of the CLUE I and CLUE II cohorts. Archived serum samples collected from participants in 1974 (in CLUE I) were analyzed using immunoblotting for immunoglobulin G (IgG) antibody levels to 13 bacteria of the periodontium. Associations between antibody levels and lung cancer were estimated using conditional logistic regression. Most of the periodontal bacterial antibodies measured were inversely associated with lung cancer risk; of these, 3 were statistically significant (Prevotellaintermedia, Actinomyces naeslundii, and Veillonella parvula). A statistically significant positive association was observed for one of the Porphyromonas gingivalis strains after adjusting for P. intermedia. The sum of the logarithm of antibodies against the 13 measured bacteria was inversely associated with risk of lung cancer when the analysis was restricted to a longer follow-up (31-44 years after blood collection, highest vs lowest quartile: odds ratio = 0.26, 95% confidence interval = 0.08 to 0.84). Findings from this study highlight the complexity of using serum IgG antibodies to periodontal bacteria to identify associations between oral pathogens and risk of lung cancer. The inverse associations observed for antibodies to periodontal bacteria suggest that these may represent markers of immunity that provide some advantage in reducing the development of lung cancer.

High-fat diet and oral infection induced type 2 diabetes and obesity development under different genetic backgrounds.

Type 2 diabetes (T2D) is an adult-onset and obese form of diabetes caused by an interplay between genetic, epigenetic, and environmental components. Here, we have assessed a cohort of 11 genetically different collaborative cross (CC) mouse lines comprised of both sexes for T2D and obesity developments in response to oral infection and high-fat diet (HFD) challenges. Mice were fed with either the HFD or the standard chow diet (control group) for 12 weeks starting at the age of 8 weeks. At week 5 of the experiment, half of the mice of each diet group were infected with Porphyromonas gingivalis and Fusobacterium nucleatum bacteria strains. Throughout the 12-week experimental period, body weight (BW) was recorded biweekly, and intraperitoneal glucose tolerance tests were performed at weeks 6 and 12 of the experiment to evaluate the glucose tolerance status of mice. Statistical analysis has shown the significance of phenotypic variations between the CC lines, which have different genetic backgrounds and sex effects in different experimental groups. The heritability of the studied phenotypes was estimated and ranged between 0.45 and 0.85. We applied machine learning methods to make an early call for T2D and its prognosis. The results showed that classification with random forest could reach the highest accuracy classification(ACC=0.91) when all the attributes were used. Using sex, diet, infection status, initial BW, and area under the curve (AUC) at week 6, we could classify the final phenotypes/outcomes at the end stage of the experiment (at 12 weeks).

Intestinal cancer development in response to oral infection with high-fat diet-induced Type 2 diabetes (T2D) in collaborative cross mice under different host genetic background effects.

Type 2 diabetes (T2D) is a metabolic disease with an imbalance in blood glucose concentration. There are significant studies currently showing association between T2D and intestinal cancer developments. High-fat diet (HFD) plays part in the disease development of T2D, intestinal cancer and infectious diseases through many biological mechanisms, including but not limited to inflammation. Understanding the system genetics of the multimorbidity of these diseases will provide an important knowledge and platform for dissecting the complexity of these diseases. Furthermore, in this study we used some machine learning (ML) models to explore more aspects of diabetes mellitus. The ultimate aim of this project is to study the genetic factors, which underline T2D development, associated with intestinal cancer in response to a HFD consumption and oral coinfection, jointly or separately, on the same host genetic background. A cohort of 307 mice of eight different CC mouse lines in the four experimental groups was assessed. The mice were maintained on either HFD or chow diet (CHD) for 12-week period, while half of each dietary group was either coinfected with oral bacteria or uninfected. Host response to a glucose load and clearance was assessed using intraperitoneal glucose tolerance test (IPGTT) at two time points (weeks 6 and 12) during the experiment period and, subsequently, was translated to area under curve (AUC) values. At week 5 of the experiment, mice of group two and four were coinfected with Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn) strains, three times a week, while keeping the other uninfected mice as a control group. At week 12, mice were killed, small intestines and colon were extracted, and subsequently, the polyp counts were assessed; as well, the intestine lengths and size were measured. Our results have shown that there is a significant variation in polyp's number in different CC lines, with a spectrum between 2.5 and 12.8 total polyps on average. There was a significant correlation between area under curve (AUC) and intestine measurements, including polyp counts, length and size. In addition, our results have shown a significant sex effect on polyp development and glucose tolerance ability with males more susceptible to HFD than females by showing higher AUC in the glucose tolerance test. The ML results showed that classification with random forest could reach the highest accuracy when all the attributes were used. These results provide an excellent platform for proceeding toward understanding the nature of the genes involved in resistance and rate of development of intestinal cancer and T2D induced by HFD and oral coinfection. Once obtained, such data can be used to predict individual risk for developing these diseases and to establish the genetically based strategy for their prevention and treatment.

Evaluation the effectivness of Phycocyanin as antibiotic against Porphyromonas gingivalis

Porphyromonas gingivalis (P. gingivalis) is considered as one of the major causes for periodontitis that eventually lead to health complications and teeth loss. In this study, crude protein extract of phycocyanin (C-PC) from Spirulina platensis that extract by precipitation and freezing/thawing methods, was assessed for its antimicrobial activity against its growth ATCC 33277, W50 wild type and W50 (Kgp-) W50 (Rgp-) mutant type P. gingivalis strains were used to evaluate C-PC action in the bacterial inhibition at different concentrations. The results showed that there was a decrease in ratio of the surface area for growth of bacteria has encountered in the W50 mutation strain at higher concentrations. This knowledge can be useful for the development of new oral hygienic treatments containing C-PC in the future