Gene expression profile of early in vitro biofilms of Streptococcus pneumoniae

Abstract

In this study, the gene expression profile of early in vitro Streptococcus pneumoniae biofilm with respect to planktonic cells in cDNA microarray analysis is reported. Microarray analysis with respect to planktonic cells was performed on total RNA extracted from biofilms grown in 24‐well microtiter plates. To validate the microarray results, real‐time RT‐PCR was performed on 13 differentially expressed genes and one constitutively expressed gene. The cDNA‐microarray analyses identified 89 genes that were significantly differentially expressed in biofilm and planktonic cells. Genes involved in isoprenoid biosynthesis, cell wall biosynthesis, translation and purine and pyrimidine nucleotide metabolic pathways were exclusively expressed in the biofilms, whereas transcription regulator genes were exclusively expressed in planktonic cells. The real‐time RT‐PCR results of 13 differentially regulated genes were completely in agreement with the microarray data. The exclusive up regulation in biofilms of genes involved in the mevalonate pathway, cell wall biosynthesis, translation and purine and pyrimidine nucleotide metabolic pathways suggests that expression of these genes may be required for initial biofilm formation, and growth and survival of bacteria in biofilms. The up regulation of related genes suggests that cells in biofilms may be under stress conditions and possibly actively involved in the protein synthesis required to adapt to a new environment.

Morphological and proteomic analysis of biofilms from the Antarctic archaeon, Halorubrum lacusprofundi

“…The requirement for purine synthesis is a characteristic of bacterial biofilms707172; for example, Bacillus cereus produces extracellular material containing extracellular DNA, but mutants with defects in purine biosynthesis fail to synthesize biofilms70. For some bacterial biofilms, cell lysis and/or secretion of DNA are the main sources of extracellular DNA737475.…”

Inhibition of Salmonella enterica Biofilm Formation Using Small-Molecule Adenosine Mimetics

“…DeoD also has been previously implicated in bacterial multicellular behavior, having been found to be significantly increased in biofilms of E. coli lacking the biofilm-repressing ycfR (63). Additionally development of rugose colony morphology in Vibrio (64) and early attachment and biofilm formation in Streptococcus have been shown to be dependent on DeoD activity (65). Subsequent studies will focus on employing heterologous deletions in these putative target proteins to establish whether they are important in Salmonella biofilm formation and to better understand how compound 7955004 is working in the early stages of biofilm formation.…”

Initial biochemical and functional characterization of a 5′-nucleotidase from Xylella fastidiosa related to the human cytosolic 5′-nucleotidase I

“…3). Studies focusing on the differential gene expression between the biofilm and planktonic lifestyles of bacterial growth commonly use techniques such as RT-PCR and DNA microarray technology [20,31,32]; however, such techniques only provide an indication of the presence of mRNA and do not confirm the presence of expressed protein. In contrast, experimental approaches based on direct protein detection may lead to more accurate results concerning the presence and biological role played by a certain protein.…”