Chang-Eun Park

Naegleria fowleri Lysate Induces Strong Cytopathic Effects and Pro-inflammatory Cytokine Release in Rat Microglial Cells

Naegleria fowleri, a ubiquitous free-living ameba, causes fatal primary amebic meningoencephalitis in humans. N. fowleri trophozoites are known to induce cytopathic changes upon contact with microglial cells, including necrotic and apoptotic cell death and pro-inflammatory cytokine release. In this study, we treated rat microglial cells with amebic lysate to probe contact-independent mechanisms for cytotoxicity, determining through a combination of light microscopy and scanning and transmission electron microscopy whether N. fowleri lysate could effect on both necrosis and apoptosis on microglia in a time- as well as dose-dependent fashion. A 51Cr release assay demonstrated pronounced lysate induction of cytotoxicity (71.5%) toward microglial cells by 24 hr after its addition to cultures. In an assay of pro-inflammatory cytokine release, microglial cells treated with N. fowleri lysate produced TNF-α, IL-6, and IL-1β, though generation of the former 2 cytokines was reduced with time, and that of the last increased throughout the experimental period. In summary, N. fowleri lysate exerted strong cytopathic effects on microglial cells, and elicited pro-inflammatory cytokine release as a primary immune response.

Study on Convergence Technique Using the Antimicrobial Resistance and Virulence Genes Analysis in Escherichia coli

This study was conducted to investigate the characteristics of antibiotic resistant E. coli. its antibiotic susceptibility and pathogenicity were analyzed via molecular convergence technique, for the relationship of antibiotic susceptibility and pathogenicity. The 60 isolated strains consisted of ESBL(+)(8) and ESBL(-)(52) strains. The ESBL(+)(8) strains consisted of 2 strains without a pathogenic gene, stb(3), flich7(1), and flich7-eae(2). The ESBL(-)(52) strains consisted of 26 strains without a pathogenic gene, stx1(3), stb(10), flich7(2), eae(2), stx1-flich7(2), stx1-stb(4), flich7-stb(2), and flich7-stb-eae(1). In conclusion, antibiotic resistance is increasingly, Focused on molecular convergence, showed the correlation of pathogenicity with antibiotic resistance was poor. However, It will be able to find the exact pathogenic factor in the future through convergence technique including the analysis of virulence genes.