Characterization and validation of an alternative reference bacterium Korean Pharmacopoeia Staphylococcus aureus strain.

The National Culture Collection of Pathogens (NCCP) is a microbial resource bank in Korea that collects pathogen resources causing infectious disease in human and distributes them for research and education. The NCCP bank attempts to discover strains with various characteristics and specific purposes to provide diverse resources to researchers. Staphylococcus aureus American Type Culture Collection (ATCC) 6538P is used as a reference strain in the microbial assay for antibiotics in the Korean and in the United States Pharmacopoeias. We aimed to analyze domestically isolated microbial resources from the NCCP to replace the S. aureus reference strain. Staphylococcus aureus strains were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and the VITEK-2 system and characterized by multilocus sequence typing, 16S rRNA sequencing, and antibiotic susceptibility testing. Several candidate strains had similar characteristics as the reference strain. Among them, the nucleotide sequence of the 16S rRNA region of NCCP 16830 was 100% identical to that of the reference strain; it was sensitive to six types of antibiotics and showed results most similar to the reference strain. A validity evaluation was conducted using the cylinder-plate method. NCCP 16830 presented valid results and had the same performance as ATCC 6538P; therefore, it was selected as an alternative candidate strain.

Complete Genome Sequences of Micrococcus luteus Strains NCCP 15687 and NCCP 16831, Isolated in South Korea.

In this study, the complete genome sequences of Micrococcus luteus strains NCCP 15687 and NCCP 16831 were determined and deposited in the National Culture Collection for Pathogens (NCCP) of South Korea. Genomic DNA was isolated from blood samples from patients infected with M. luteus.

Sulforaphane exerts its anti-inflammatory effect against amyloid-ß peptide via STAT-1 dephosphorylation and activation of Nrf2/HO-1 cascade in human THP-1 macrophages.

Alzheimer's disease (AD) is the most common neurodegenerative disorder worldwide, accounting for most cases of dementia in elderly individuals, and effective therapies are still lacking. This study was designed to investigate the anti-inflammatory properties of sulforaphane against Aß1-42 monomers in human THP-1 microglia-like cells. The results showed that sulforaphane preferentially inhibited cathepsin B- and caspase-1-dependent NLRP3 inflammasome activation induced by mostly Aß1-42 monomers, an effect that potently reduced excessive secretion of the proinflammatory cytokine interleukin-1ß (IL-1ß). Subsequent mechanistic studies revealed that sulforaphane mitigated the activation of signal transducer and activator of transcription-1 induced by Aß1-42 monomers. Sulforaphane also increased nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation, which was followed by upregulation of heme-oxygenase 1 (HO-1). The anti-inflammatory effect of sulforaphane on Aß1-42-induced IL-1ß production was diminished by small interfering RNA-mediated knockdown of Nrf2 or HO-1. Moreover, sulforaphane significantly attenuated the levels of microRNA-146a, which is selectively upregulated in the temporal cortex and hippocampus of AD brains. The aforementioned effects of sulforaphane were replicated by the tyrosine kinase inhibitor, herbimycin A, and Nrf2 activator. These results indicate that signal transducer and activator of transcription-1 dephosphorylation, HO-1 and its upstream effector, Nrf2, play a pivotal role in triggering an anti-inflammatory signaling cascade of sulforaphane that results in decreases of IL-1ß release and microRNA-146a production in Aß1-42-stimulated human microglia-like cells. These findings suggest that the phytochemical sulforaphane has a potential application in AD therapeutics.