Comparative gene expression analysis of Porphyromonas gingivalis ATCC 33277 in planktonic and biofilms states

Abstract

Background and objectivePorphyromonas gingivalis is a keystone pathogen in the onset and progression of periodontitis. Its pathogenicity has been related to its presence and survival within the subgingival biofilm. The aim of the present study was to compare the genome-wide transcription activities of P. gingivalis in biofilm and in planktonic growth, using microarray technology.Material and methodsP. gingivalis ATCC 33277 was incubated in multi-well culture plates at 37°C for 96 hours under anaerobic conditions using an in vitro static model to develop both the planktonic and biofilm states (the latter over sterile ceramic calcium hydroxyapatite discs). The biofilm development was monitored by Confocal Laser Scanning Microscopy (CLSM) and Scanning Electron Microscopy (SEM). After incubation, the bacterial cells were harvested and total RNA was extracted and purified. Three biological replicates for each cell state were independently hybridized for transcriptomic comparisons. A linear model was used for determining differentially expressed genes and reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used to confirm differential expression. The filtering criteria of ≥ ±2 change in gene expression and significance p-values of <0.05 were selected.ResultsA total of 92 out of 1,909 genes (4.8%) were differentially expressed by P. gingivalis growing in biofilm compared to planktonic. The 54 up-regulated genes in biofilm growth were mainly related to cell envelope, transport, and binding or outer membranes proteins. Thirty-eight showed decreased expression, mainly genes related to transposases or oxidative stress.ConclusionThe adaptive response of P. gingivalis in biofilm growth demonstrated a differential gene expression.

Helicobacter pylori Biofilm Involves a Multigene Stress-Biased Response, Including a Structural Role for Flagella

“…To gain insights into the mechanisms behind the biofilm formation in H. pylori , we used RNA sequencing and carried out a comparative transcriptomic analysis between biofilm cells and those in the planktonic state. Using this approach, we observed that 8.18% of genes were significantly differentially expressed between biofilm and planktonic cells, similar to what has been reported in other bacterial systems ( 43 , 45 , 46 ). In our experimental design, we compared a static biofilm mode of growth, where attached cells adhered to the bottom of the wells, with planktonic nonattached cells in the same wells.…”

The Helicobacter pylori biofilm involves a multi-gene stress-biased response including a structural role for flagella

“…To gain insights into the mechanisms behind the biofilm formation in H. pylori, we used RNA sequencing and carried out a comparative transcriptomic analysis between biofilm cells and those in the planktonic state. Using this approach, we observed that 8.18% of genes were significantly differentially expressed between biofilm and planktonic cells, similar to that reported in other bacterial systems (43,45,46). In our experimental design, we compared a static biofilm mode of growth, where attached cells adhered to the bottom of the wells, with planktonic non-attached cells in the same wells.…”

A Novel Mechanism, Linked to Cell Density, Largely Controls Cell Division in Synechocystis

“…This observation suggests that Synechocystis growth regulation differs when cultured on an agar surface or in liquid. Data from the literature show that heterotrophic bacteria exhibit different gene expression patterns in biofilm and in planktonic growth (Imanaka et al, 2010;He and Ahn, 2011;Romero-Lastra et al, 2017). Among the genes that are up-regulated under biofilm conditions, some encode proteins located in the outer membrane or cell envelope and involved in transport or binding (Romero-Lastra et al, 2017).…”

“…Data from the literature show that heterotrophic bacteria exhibit different gene expression patterns in biofilm and in planktonic growth (Imanaka et al, 2010;He and Ahn, 2011;Romero-Lastra et al, 2017). Among the genes that are up-regulated under biofilm conditions, some encode proteins located in the outer membrane or cell envelope and involved in transport or binding (Romero-Lastra et al, 2017). Furthermore, a significant number of the genes differentially expressed encode for proteins of unknown functions (Imanaka et al, 2010).…”