Gene expression profile of early in vitro biofilms of Streptococcus pneumoniae.
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.
Department of Otorhinolaryngology-Head and Neck Surgery, Dongguk University Ilsan Hospital, 814 Siksa-Dong, Goyang, Gyeonggi, South Korea.
Mukesh Kumar
MK
Yadav
Seong Keun
SK
Kwon
Chang Gun
CG
Cho
Seok-Won
SW
Park
Sung-Won
SW
Chae
Jae-Jun
JJ
Song
D018441:Biofilms; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005809:Genes, Regulator; D020411:Oligonucleotide Array Sequence Analysis; D014176:Protein Biosynthesis; D011685:Purine Nucleotides / Q000235:genetics / Q000378:metabolism; D011742:Pyrimidine Nucleotides / Q000235:genetics / Q000378:metabolism; D012329:RNA, Bacterial / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013296:Streptococcus pneumoniae / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D013729:Terpenes / Q000378:metabolism; D014158:Transcription, Genetic; D059467:Transcriptome
D011685:Purine Nucleotides; D011742:Pyrimidine Nucleotides; D012329:RNA, Bacterial; D013729:Terpenes