Manumycin from a new Streptomyces strain shows antagonistic effect against methicillin-resistant Staphylococcus aureus (MRSA)/vancomycin-resistant enterococci (VRE) strains from Korean Hospitals

An antimicrobial compound, highly effective against multidrug-resistant (MDR) bacteria, purified from a Streptomyces strain was identified as manumycin. The minimal inhibitory concentrations (MICs) of manumycin against 8 different strains of methicillin-resistant Staphylococcus aureus (MRSA) were ranged 2 to 32 μg/ml. Similarly, MICs of manumycin against 4 vancomycin-resistant enterococci (VRE) strains were ranged 8 to 32 μg/ml while it remained ineffective against 4 other VRE strains. Compared to vancomycin, manumycin provided slightly weaker activity against MRSA strains but stronger activity against 4 VRE strains. This is the first report of antagonistic effect of manumycin against MDR pathogens.Keywords: Manumycin, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE)African Journal of Biotechnology Vol. 12(17), pp. 2249-225

Beclin 1 functions as a negative modulator of MLKL oligomerisation by integrating into the necrosome complex

Necroptosis is a form of regulated cell death caused by formation of the necrosome complex. However, the factors modulating this process and the systemic pathophysiological effects of necroptosis are yet to be understood. Here, we identified that Beclin 1 functions as an anti-necroptosis factor by being recruited into the necrosome complex upon treatment with TNF alpha, Smac mimetic, and pan-caspase inhibitor and by repressing MLKL oligomerisation, thus preventing the disruption of the plasma membrane. Cells ablated or knocked-out for Beclin 1 become sensitised to necroptosis in an autophagy-independent manner without affecting the necrosome formation itself. Interestingly, the recruitment of Beclin 1 into the necrosome complex is dependent on the activation and phosphorylation of MLKL. Biochemically, the coiled-coil domain (CCD) of Beclin 1 binds to the CCD of MLKL, which restrains the oligomerisation of phosphorylated MLKL. Finally, Beclin 1 depletion was found to promote necroptosis in leukaemia cells and enhance regression of xenografted-tumour upon treatment with Smac mimetics and caspase inhibitors. These results suggest that Beclin 1 functions as a negative regulator in the execution of necroptosis by suppressing MLKL oligomerisation

Identification of MYC as an antinecroptotic protein that stifles RIPK1-RIPK3 complex formation

The underlying mechanism of necroptosis in relation to cancer is still unclear. Here, MYC, a potent oncogene, is an antinecroptotic factor that directly suppresses the formation of the RIPK1-RIPK3 complex. Gene set enrichment analyses reveal that the MYC pathway is the most prominently down-regulated signaling pathway during necroptosis. Depletion or deletion of MYC promotes the RIPK1-RIPK3 interaction, thereby stabilizing the RIPK1 and RIPK3 proteins and facilitating necroptosis. Interestingly, MYC binds to RIPK3 in the cytoplasm and inhibits the interaction between RIPK1 and RIPK3 in vitro. Furthermore, MYC-nick, a truncated form that is mainly localized in the cytoplasm, prevented TNF-induced necroptosis. Finally, down-regulation of MYC enhances necroptosis in leukemia cells and suppresses tumor growth in a xenograft model upon treatment with birinapant and emricasan. MYC-mediated suppression of necroptosis is a mechanism of necroptosis resistance in cancer, and approaches targeting MYC to induce necroptosis represent an attractive therapeutic strategy for cancer

Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

Nocardioides dokdonensis sp. nov., an actinomycete isolated from sand sediment

A strictly aerobic, non-motile, short rod-shaped actinomycete, designated strain FR1436(T), was isolated from sand sediment from a beach on Dokdo Island, Republic of Korea. The major menaquinone was MK-8(H(4)), the predominant cellular fatty acid was iso-C(16:0) (40.4 %) and the G + C content of the DNA was 69.1 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain FR1436(T) formed a lineage within the genus Nocardioides and was closely related to Nocardioides marinisabuli SBS-12(T) (97.8% sequence similarity) and Nocardioides salarius CL-Z59(T) (97.4%). Phenotypic characteristics and DNA-DNA relatedness data served to distinguish strain FR1436(T) from N. marinisabuli. On the basis of the evidence presented in this study, strain FR1436(T) represents a novel species of the genus Nocardioides, for which the name Nocardioides dokdonensis sp. nov. is proposed. The type strain is FR1436(T) (=KCTC 19309(T) = JCM 14815(T)).

Anti-Pigmentary Effect of (-)-4-Hydroxysattabacin from the Marine-Derived Bacterium Bacillus sp.

Bioactivity-guided isolation of a crude extract from a culture broth of Bacillus sp. has led to the isolation of (-)-4-hydroxysattabacin (1). The inhibitory effect of (-)-4-hydroxysattabacin (1) was investigated on melanogenesis in the murine melanoma cell line, B16F10, and human melanoma cell line, MNT-1, as well as a pigmented 3D-human skin model. (-)-4-Hydroxysattabacin treatment decreased melanin contents in a dose-dependent manner in α-melanocyte stimulating hormone (α-MSH)-stimulated B16F10 cells. Quantitative real time PCR (qRT–PCR) demonstrated that treatment with (-)-4-hydroxysattabacin down-regulated several melanogenic genes, including tyrosinase, tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2) while their enzymatic activities were unaffected. The anti-melanogenic effects of (-)-4-hydroxysattabacin were further demonstrated in a pigmented 3D human epidermal skin model, MelanodermTM, and manifested as whitening and regression of melanocyte activation in the tissue

Luteimonas marina sp. nov., isolated from seawater

A marine bacterial strain, designated FR1330(T), was isolated from a seawater sample collected near Ganghwa Island, the Republic of Korea. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain FR1330(T) belonged to the Gammaproteobacteria and was related to the genus Luteimonas; its closest neighbours were the type strains of Luteimonas composti (97.9 % sequence similarity) and Luteimonas mephitis (95.0 %). DNA-DNA relatedness values for strain FR1330(T) with Luteimonas composti CC-YY255(T) and Luteimonas mephitis KACC 11391(T) were 33 and 10 %, respectively. Cells of strain FR1330(T) were Gram-negative, aerobic, rod-shaped and oxidase- and catalase-positive. The predominant respiratory lipoquinone was ubiquinone-8. The major fatty acids were branched-chain saturated iso-C(15:0) (26.2 %) and unsaturated iso-C(17:1)omega 9c (26.0 %). The DNA G + C content was 67.6 mol%. On the basis of several phenotypic characteristics, strain FR1330(T) could be differentiated from Luteimonas composti and Luteimonas mephitis. The data obtained from the polyphasic study demonstrated clearly that strain FR1330(T) represents a novel species of the genus Luteimonas. The name Luteimonas marina sp. nov. is proposed, with strain FR1330(T) (=KCTC 12327(T) = JCM 12488(T) = IMSNU 60306(T)) as the type strain.

Photobacterium ganghwense sp. nov., a halophilic bacterium isolated from sea water

A marine bacterial strain, designated FR1311(T), was isolated from a sea-water sample from Ganghwa. Island, South Korea. Cells were Gram-negative, facultatively anaerobic, catalase- and oxidase-positive, motile, oval or rod-shaped and halophilic, (optimum sea-salt concentration for growth of 5-6%). Phylogenetic analysis of its 16S rRNA gene sequence revealed that it represented a distinct line of descent within the genus Photobacterium. The major fatty acids were straight-chain saturated (C-16:0) and monounsaturated fatty acids (C(16:)1 omega 7c and C-18:1 omega 7c). The predominant respiratory lipoquinone was Q-8. The DNA G + C content was 44 mol%. The phenotypic features of strain FR1199(T) were similar to those of Photobacterium damselae subsp. damselae and Photobacterium damselae subsp. piscicida, but several physiological and chemotaxonomic properties readily distinguish the new isolate from them. On the basis of the polyphasic results revealed in this study, FR1311(T) is considered to be the type strain of a novel species, for which the name Photobacterium ganghwense sp. nov. is proposed. The type strain is FR1311(T) (=IMSNU 60287(T) =KCTC 12328(T)=JCM 12487(T)).