Korea University · Medicine
Professor Jae-Jun Song's research lab focuses on microbial biofilm-related infections, particularly those caused by *Staphylococcus aureus*, *Streptococcus pneumoniae*, and *Pseudomonas aeruginosa*. The lab investigates the molecular mechanisms of biofilm formation, quorum-sensing systems (such as LuxS/AI-2), and host-pathogen interactions in chronic infections like otitis media, wound infections, and cystic fibrosis. It also explores novel therapeutic strategies, including natural compounds (e.g., eugenol, sinefungin), repurposed drugs (e.g., disulfiram), and neuromodulation (e.g., transcutaneous auricular VNS) to disrupt biofilms and reduce inflammation.
Figures are computed from collected data and may differ slightly.
This study demonstrated that eugenol exhibits notable activity against MRSA and MSSA clinical strains biofilms. Eugenol inhibited biofilm formation, disrupted the cell-to-cell connections, detached the existing biofilms, and killed the bacteria in biofilms of both MRSA and MSSA with equal effectiveness. Therefore, eugenol may be used to control or eradicate S. aureus biofilm-related infections.
<b>Objective:</b><i>Streptococcus pneumoniae</i> colonizes the nasopharynx of children, and from nasopharynx it could migrate to the middle ear and causes acute otitis media (AOM). During colonization and AOM, the pneumococcus forms biofilms. <i>In vitro</i> biofilm formation requires a functional LuxS/AI-2 quorum-sensing system. We investigated the role of LuxS/AI-2 signaling in pneumococcal middle ear infection, and identified the genes that are regulated by LuxS/AI-2 during pneumococcal biofi
<i>Staphylococcus aureus</i> (SA) and <i>Pseudomonas aeruginosa</i> (PA) are known to cause biofilm-related infections. MRSA and PA have been frequently isolated from chronically infected wounds, cystic fibrosis, chronic suppurative otitis media (CSOM), and from indwelling medical devices, and these bacteria co-exist; however, their interaction with each-other or with the host is not well known. In this study, we investigated MRSA and PA multi-species biofilm communities <i>in vitro</i> and thei
In treating patients with HNSCC, DSF may contribute to improved HNSCC patient's survival. The characteristic anti-cancer effects of DSF on HNSCC may suggest new therapeutic potential for this medication in HNSCC patients.
Pneumococcal colonization and disease is often associated with biofilm formation, in which the bacteria exhibit elevated resistance both to antibiotics and to host defense systems, often resulting in infections that are persistent and difficult to treat. We evaluated the effect of sinefungin, a nucleoside analogue of S-adenosylmethionine, on pneumococcal in vitro biofilm formation and in vivo colonization. Sinefungin is bacteriostatic to pneumococci and significantly decreased biofilm growth and
Vagus nerve stimulation (VNS) is considered a potential method for anti-inflammation due to the involvement of the VN in the cholinergic anti-inflammatory pathway (CAP) formation of a connection between the central nervous system and peripheral immune cells that help relieve inflammation. However, whether a non-invasive transcutaneous auricular VNS (taVNS) modulates the inflammation levels via altering the parameter of taVNS is poorly understood. This study aimed to determine the differential in
Human amniotic membrane extracts contain numerous growth factors and bioactive substances. However, osteogenic effects of amnion and chorion membrane extracts (AME and CME, respectively) on osteoblasts are unclear. In this study, we explored the ability of AME and CME to promote the osteogenic differentiation of osteoblast-like MG-63 cells. MG-63 cells were cultured in osteogenic induction medium (OIM) with or without exogenous AME and CME. CME enhanced the osteogenic differentiation of MG-63 ce
In this study, we investigate the antimicrobial activities of both Eugenia caryophyllata (Ec) extract and its major component eugenol (4-allyl-2-methoxyphenol) against Streptococcus pneumoniae. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by microdilution method. Pneumococcal biofilms were detected by crystal-violet microtiter plate assay, followed by colony-forming unit counts and visualized by scanning electron microscope (SEM). The sy
<b>Background:</b><i>Streptococcus pneumoniae</i> colonize the human nasopharynx in the form of biofilms. The biofilms act as bacterial reservoirs and planktonic bacteria from these biofilms can migrate to other sterile anatomical sites to cause pneumonia, otitis media (OM), bacteremia and meningitis. Human amniotic membrane contains numerous growth factors and antimicrobial activity; however, these have not been studied in detail. In this study, we prepared amniotic membrane extract and chorion
The poly(3-hydroxybutyrate) (PHB) synthase of Ralstonia eutropha, which was produced by a recombinant strain of Escherichia coli and purified in one step with a methyl-HIC column to a purity of more than 90%, was used to polymerize 3-hydroxypropionyl-CoA (3HPCoA) and to copolymerize 3HPCoA with 3-hydroxybutyryl-CoA (3HBCoA). A Km of 189 microM and a kcat of 10 s-1 were determined for the activity of the enzyme in the polymerization reaction of 3HPCoA based on the assumption that the dimer form o
CAPE significantly inhibited LPS-induced up-regulation of TNF-alpha in a dose-dependent manner. IL-8 production by LPS was significantly suppressed by the CAPE pretreatment. Furthermore, LPS-induced IkappaB-alpha degradation was suppressed by the CAPE pretreatment.
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