Project description:Wild type Porphyromonas gingivalis strain ATCC33277 (V3176) and PG1626 - deficient mutant (V3177) were grown in iron replete conditions was used to compare to Porphyromonas gingivalis strains grown in iron chelated conditions.
Project description:RNA-Seq of wild-type Porphyromonas gingivalis compared to ΔPGN_1524 mutant Illumina based RNA-Seq was used to probe transcriptome differences between wild-type Porphyromonas gingivalis and ΔPGN_1524 mutant
Project description:Periodontal diseases are one of the most common human maladies and appear to be caused by the interaction of proximal pathogens such as Porphyromonas gingivalis but only as part of the polymicrobial community known as dental plaque. Streptococcus gordonii is an early colonizing oral organism that binds to oral surfaces and provides adherence for organisms such as P. gingivalis. Together P. gingivalis and S. gordonii form one of the simplest models of potentially pathogenic dental plaque. We used RNA sequencing to monitor the transcriptome of P. gingivalis over time in a biofilm model both in the presence and absence of S. gordonii. Samples were taken at 5, 30, 120, 240, and 360 minutes after shifing from planktonic to sessile conditions and growth media to PBS. When compared to planktonic cells increased transcripts were found for stress, amino acid catabolism, and comeptence and decreased transcripts for DNA replication. The presence of S. gordonii resulted in fewer changes from planktonic cells implying physiological support to Pl gingivalis making the transition from planktonic to sessile easier.
Project description:Porphyromonas gingivalis and Treponema denticola are periodontalpathogens that are associated with the severity and progression of periodontal diseases. This study investigates the gene expression of Porphyromonas gingivalis during co-culture with Treponema denticola
Project description:Porphyromonas gingivalis and Treponema denticola are periodontalpathogens that are associated with the severity and progression of periodontal diseases. this study investigates the gene expression of Treponema denticola during co-culture with Porphyromonas gingivalis.
Project description:Porphyromonas gingivalis is a keystone periodontal pathogen that has been associated with autoimmune disorders. The cell surface proteases Lys-gingipain (Kgp) and Arg-gingipains (RgpA and RgpB) are major virulence factors and their proteolytic activity is enhanced by small peptides such as glycylglycine (GlyGly). The reaction kinetics suggested that GlyGly may function as an acceptor molecule for gingipain-catalysed transpeptidation. Purified gingipains and P. gingivalis whole cells were used to digest selected substrates including human haemoglobin in the presence or absence of peptide acceptors. Mass spectrometric analysis of the substrates digested with gingipains in the presence of GlyGly showed that transpeptidation outcompeted hydrolysis while the trypsin-digested controls exhibited predominantly hydrolysis activity. The transpeptidation levels increased with increasing concentration of GlyGly. Purified gingipains and whole cells exhibited extensive transpeptidation activities on human haemoglobin. All haemoglobin cleavage sites were found to be suitable for GlyGly transpeptidation and this transpeptidation enhanced haemoglobin digestion. The transpeptidation products were often more abundant than the corresponding hydrolysis products. In the absence of GlyGly, haemoglobin peptides produced during digestion were utilised as acceptors leading to the detection of up to 116 different transpeptidation products in a single reaction. P. gingivalis cells were able to digest haemoglobin faster when acceptor peptides derived from human serum albumin were included in the reaction suggesting that gingipain-catalysed transpeptidation may be relevant for substrates encountered in vivo. The transpeptidation of host proteins in vivo may potentially lead to the breakdown of immunological tolerance culminating in autoimmune reactions.
Project description:This project investigated the phenotypic characteristics of Metronidazole-tolerant Porphyromonas gingivalis persisters, the relevant modulatory effects of hemin and their underlying survival mechanisms. Proteomic analysis was performed to delineate the protein expression profiles of Metronidazole-tolerant P. gingivalis persister fractions and the controls incubated with different levels of hemin supplementation.
