Sphingomonas gotjawalisoli sp. nov., isolated from soil of a lava forest.

A bacterial strain, designated SN6-9T, was isolated from soil of the Gotjawal, lava forest, located in Jeju, Republic of Korea. Strain SN6-9T was Gram-stain-negative, motile, oxidase- and catalase-negative, yellow-pigmented and rod-shaped. It contained summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) as the major fatty acids, Q-10 as the predominant isoprenoid quinone, sym-homospermidine as the major polyamine and diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid and two unidentified phospholipids as the polar lipids. The DNA G+C content was 64.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the strain formed a separate lineage in the genus Sphingomonas. Based on the results from this polyphasic taxonomic study, it is concluded that strain SN6-9T represents a novel species in the genus Sphingomonas. The name Sphingomonas gotjawalisoli sp. nov. is proposed; the type strain is SN6-9T (=KCTC 52405T=NRRL B-65395T).

Nocardioides daeguensis sp. nov., a nitrate-reducing bacterium isolated from activated sludge of an industrial wastewater treatment plant.

A Gram-reaction-positive, rod-shaped, non-spore-forming bacterium (strain 2C1-5(T)) was isolated from activated sludge of an industrial wastewater treatment plant in Daegu, South Korea. Its taxonomic position was investigated by using a polyphasic approach. On the basis of 16S rRNA gene sequence similarity, the closest phylogenetic relatives were the type strains of Nocardioides nitrophenolicus (98.6 % similarity), N. kongjuensis (98.5 %), N. caeni (98.4 %), N. simplex (98.3 %), N. aromaticivorans (98.1 %) and N. ginsengisoli (97.5 %); the phylogenetic distance from other species with validly published names within the genus Nocardioides was greater than 3 %. Strain 2C1-5(T) was characterized chemotaxonomically as having ll-2,6-diaminopimelic acid in the cell-wall peptidoglycan, MK-8(H4) as the predominant menaquinone and iso-C16 : 0, C16 : 0 and C17 : 1ω6c as the major fatty acids. The G+C content of the genomic DNA was 74.9 mol%. These chemotaxonomic properties and phenotypic characteristics supported the affiliation of strain 2C1-5(T) to the genus Nocardioides. The results of physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain 2C1-5(T) from existing species with validly published names. Therefore, strain 2C1-5(T) represents a novel species of the genus Nocardioides, for which the name Nocardioides daeguensis sp. nov. is proposed, with the type strain 2C1-5(T) ( = JCM 17460(T) = KCTC 19799(T)).

Brevibacterium daeguense sp. nov., a nitrate-reducing bacterium isolated from a 4-chlorophenol enrichment culture.

A Gram-reaction-positive, non-spore-forming, aerobic actinobacterial strain (2C6-41(T)) was isolated from the activated sludge from an industrial wastewater treatment plant in Daegu, South Korea. Its taxonomic position was investigated by using a polyphasic approach. On the basis of 16S rRNA gene sequence similarity, closest phylogenetic relatives to strain 2C6-41(T) were Brevibacterium pityocampae DSM 21720(T) (97.2 %), Brevibacterium salitolerans KCTC 19616(T) (96.7 %), Brevibacterium album KCTC 19173(T) (96.2 %) and Brevibacterium samyangense KCCM 42316(T) (96.2 %). The DNA G+C content of strain 2C6-41(T) was 66.4 mol%. Chemotaxonomic data, which included MK-8(H(2)) as the major menaquinone; meso-diaminopimelic acid, glutamic acid and alanine as cell-wall amino acids; ribose, mannose and glucose as major cell-wall sugars; and anteiso-C(15 : 0), anteiso-C(17 : 0), C(16 : 0) and iso-C(15 : 0) as major fatty acids, supported the affiliation of strain 2C6-41(T) to the genus Brevibacterium. The aromatic ring cleavage enzyme catechol 1,2-dioxygenase was not detected in strain 2C6-41(T), but catechol 2,3-dioxygenase was detected. The results of physiological and biochemical tests, and the low level of DNA-DNA relatedness to the closest phylogenetic relative enabled strain 2C6-41(T) to be differentiated genotypically and phenotypically from recognized species of the genus Brevibacterium. The isolate is therefore considered to represent a novel species in the genus Brevibacterium, for which the name Brevibacterium daeguense sp. nov. is proposed. The type strain is 2C6-41(T) (=KCTC 19800(T) = JCM 17458(T)).

Variovorax defluvii sp. nov., isolated from sewage.

A polyphasic taxonomic study was carried out on 2C1-b(T) and 2C-21, two strains isolated from sewage flowing into River Geumho in Korea. Cells of the two strains were Gram-negative, non-spore-forming, motile and oval or rod-shaped. Comparative 16S rRNA gene sequence studies showed a clear affiliation of these two isolates with members of the Betaproteobacteria; they were most closely related to Variovorax boronicumulans KCTC 22010(T), Variovorax dokdonensis KCTC 12544(T), Variovorax ginsengisoli KCTC 12583(T), Variovorax paradoxus ATCC 17713(T) and Variovorax soli KACC 11579(T) showing 16S rRNA gene sequence similarities of 97.4-98.8% with these strains and shared 100% similarity with each other. The genomic DNA G+C contents of strains 2C1-b(T) and 2C1-21 were 65.5 and 65.2 mol%, respectively. Phenotypic and chemotaxonomic data [Q-8 as the major ubiquinone; C(16:0), summed feature 4 (C(16:1)ω7c and/or iso-C(15:0) 2-OH), C(17:0) cyclo and summed feature 7 (C(18:1)ω7c and/or ω9t and/or ω12t) as major fatty acids] supported the affiliation of strains 2C1-b(T) and 2C-21 to the genus Variovorax. Based on evidence derived from this polyphasic analysis, it is proposed that strains 2C1-b(T) and 2C1-21 represent a novel species for which the name Variovorax defluvii sp. nov. is proposed; the type strain is 2C1-b(T) ( = KCTC 12768(T) = JCM 17804(T)).

Georgenia daeguensis sp. nov., isolated from 4-chlorophenol enrichment culture.

During screening for 4-chlorophenol-degrading micro-organisms in activated sludge from industrial wastewater treatment, a Gram-positive, rod-shaped, aerobic bacterial strain, designated 2C6-43(T), was isolated and characterized taxonomically by using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain 2C6-43(T) belongs to the family Bogoriellaceae, class Actinobacteria, and is related most closely to Georgenia soli CC-NMPT-T3(T) (98.8% sequence similarity), Georgenia muralis 1A-C(T) (97.6%), Georgenia thermotolerans TT02-04(T) (96.8%), Georgenia ruanii YIM 004(T) (96.6%) and Georgenia halophila YIM 93316(T) (96.0%). The G+C content of the genomic DNA of strain 2C6-43(T) was 66.2 mol%. Sugars from whole-cell hydrolysates found in strain 2C6-43(T) were rhamnose, ribose and galactose. The menaquinone MK-8(H(4)) was detected as the predominant quinone. Polar lipid analysis of 2C6-43(T) revealed diphosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol and phosphatidylglycerol. An aromatic compound ring cleavage enzyme of catechol 1,2-dioxygenase was detected but catechol 2,3-dioxygenase was not detected in 2C6-43(T). A fatty acid profile with anteiso-C(15:0), iso-C(15:0) and C(16:0) as the major components supported the affiliation of strain 2C6-43(T) to the genus Georgenia. However, the DNA-DNA relatedness between strain 2C6-43(T) and the type strains of five species of the genus Georgenia ranged from 17 to 40%, clearly showing that the isolate constitutes a new genospecies. Strain 2C6-43(T) could be clearly differentiated from its phylogenetic neighbours on the basis of some phenotypic, genotypic and chemotaxonomic features. Therefore, strain 2C6-43(T) is considered to represent a novel species of the genus Georgenia, for which the name Georgenia daeguensis sp. nov. is proposed; the type strain is 2C6-43(T) (=KCTC 19801(T)=JCM 17459(T)).

Effects of mycobacterial infection on proliferation of hematopoietic precursor cells.

Bacterial infection can affect hematopoietic precursor cells in bone marrow, because the infected tissues produce various cytokines and chemokines. Little is known about hematopoietic precursor cells, including hematopoietic stem cells and their progenitors, during mycobacterial infection. Here, we showed that mycobacterial infections result in the expansion of not only the lin-c-kit+sca-1+ (LKS+) cell population, but also granulocyte-monocyte progenitor cells in a chronic murine tuberculosis model. Interestingly, stimulation of LKS+ cells with attenuated Mycobacterium tuberculosis H37Ra culture filtrate (RaCF) was significantly stronger than that by virulent H37Rv culture filtrate (RvCF). Lower TNF-α and IL-6 levels were observed in RvCF-stimulated bone marrow cells. Neutralization of TNF-α or IL-6 in RaCF-stimulated bone marrow cells markedly suppressed LKS+ cell clonal expansion. Additionally, numbers of LKS+ cells were lower in TLR2(-/-) and MyD88(-/-) mice after mycobacterial infection. Taken together, LKS+ cell proliferation related to mycobacterial virulence may be related to the secretion of TNF-α and IL-6 associated with TLR signaling. Expansion of hematopoietic progenitor cells may, therefore, play an important role during mycobacterial infection.

Kaistia geumhonensis sp. nov. and Kaistia dalseonensis sp. nov., two members of the class Alphaproteobacteria.

Two strains, designated B1-1(T) and B6-8(T), were isolated from the Geumho River and the Dalseo Stream in Korea. Comparative 16S rRNA gene sequence analysis showed a clear affiliation of these two bacteria with the class Alphaproteobacteria, their closest relatives being Kaistia adipata KCTC 12095(T), Kaistia granuli KCTC 12575(T), Kaistia soli KACC 12605(T) and Kaistia terrae KACC 12910(T) with 16S rRNA gene sequence similarities of 95.3 -97.7 % to the two novel strains. Strains B1-1(T) and B6-8(T) shared a 16S rRNA gene sequence similarity value of 96.1 %. Cells of the two strains were Gram-reaction-negative, aerobic, non-motile, short rods or cocci. The predominant ubiquinone was Q-10. The major fatty acids were C(16 : 0,) C(18 : 1)ω7c, C(18 : 0) and C(19 : 0)ω8c cyclo for strain B1-1(T) and C(16 : 0,) C(18 : 1)ω7c, C(18 : 0), C(18 : 1) 2-OH, and C(19 : 0)ω8c cyclo for strain B6-8(T). The G+C contents of the genomic DNA of the strains B1-1(T) and B6-8(T) were 61.6 and 66.5 mol%, respectively. Based on the results of this polyphasic study, strains B1-1(T) ( = KCTC 12849(T) = DSM 18799(T)) and B6-8(T) ( = KCTC 12850(T) = DSM 18800(T)) represent two novel species of the genus Kaistia, for which the names Kaistia geumhonensis sp. nov. and Kaistia dalseonensis sp. nov. are proposed, respectively.

Pontibaca methylaminivorans gen. nov., sp. nov., a member of the family Rhodobacteraceae.

The alphaproteobacterial strains GRP21(T) and PH34, which were isolated from coastal sediment of the East Sea, Korea, were subjected to a polyphasic taxonomic investigation. The strains were Gram-negative, non-motile, non-spore-forming, oval-shaped rods that produced creamy-white colonies on tryptic soy agar, required NaCl for growth, contained Q-10 as the predominant ubiquinone, contained 16 : 0, 18 : 1omega7c and 19 : 0 cyclo omega8c as major fatty acids and had polar lipid profiles consisting of phosphatidylcholine, phosphatidylglycerol, an unknown aminolipid, an unknown phospholipid and three unknown lipids. Phylogenetic analysis, based on 16S rRNA gene sequencing, showed that the strains were most closely related to Donghicola eburneus KCTC 12735(T), with 94.5 % sequence similarity, but formed a separate lineage within the family Rhodobacteraceae. The combined genotypic and phenotypic data supported the conclusion that the strains represent a novel genus and species, for which the name Pontibaca methylaminivorans gen. nov., sp. nov. is proposed. The type strain of Pontibaca methylaminivorans is GRP21(T) (=KCTC 22497(T) =DSM 21219(T)).

Apurinic/apyrimidinic endonuclease 1 is a key modulator of keratinocyte inflammatory responses.

Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1) functions in both DNA repair and redox signaling, making it an attractive emerging therapeutic target. However, the role of APE1 in cutaneous inflammatory responses is largely unknown. In this study, we report that APE1 is a key upstream regulator in TLR2-dependent keratinocyte inflammatory responses. We found that nuclear expression of APE1 in epidermal layers was markedly up-regulated in psoriatic skin. APE1 was essential for the transcriptional activation and nuclear translocation of hypoxia-inducible factor-1alpha and NF-kappaB, both of which are crucial for inflammatory signaling in keratinocytes. Moreover, APE1 played a crucial role in the expression of TLR2-mediated inflammatory mediators, including TNF-alpha, CXCL8, and LL-37, in HaCaT cells and human primary keratinocytes. Silencing of APE1 attenuated cyclin D1/cyclin-dependent kinase 4 expression and phosphorylation of ERK1/2 and Akt, thereby affecting keratinocyte proliferation. Importantly, TLR2-induced generation of reactive oxygen species contributed to the nuclear translocation and expression of APE1, suggesting an autoregulatory circuit in which the subcellular localization of APE1 is associated with the production of APE1 per se through reactive oxygen species-dependent signaling. Taken together, these findings establish a role for APE1 as a master regulator of TLR2-dependent inflammatory responses in human keratinocytes.

Vitamin D3 induces autophagy in human monocytes/macrophages via cathelicidin.

Autophagy and vitamin D3-mediated innate immunity have been shown to confer protection against infection with intracellular Mycobacterium tuberculosis. Here, we show that these two antimycobacterial defenses are physiologically linked via a regulatory function of human cathelicidin (hCAP-18/LL-37), a member of the cathelicidin family of antimicrobial proteins. We show that 1,25-dihydroxyvitamin D3 (1,25D3), the active form of vitamin D, induced autophagy in human monocytes via cathelicidin, which activated transcription of the autophagy-related genes Beclin-1 and Atg5. 1,25D3 also induced the colocalization of mycobacterial phagosomes with autophagosomes in human macrophages in a cathelicidin-dependent manner. Furthermore, the antimycobacterial activity in human macrophages mediated by physiological levels of 1,25D3 required autophagy and cathelicidin. These results indicate that human cathelicidin, a protein that has direct antimicrobial activity, also serves as a mediator of vitamin D3-induced autophagy.

Acinetobacter antiviralis sp. nov., from Tobacco plant roots.

Acinetobacter strain KNF2022T was isolated from tobacco plant roots during the screening of antiviral substances having inhibitory effects on Tobacco mosaic virus (TMV) and examined by phenotypic, chemotaxonomic, and genetic characterization. It was a nonmotile, Gram-negative bacterium. This strain contained Q-9 as the main respiratory quinone. The major cellular fatty acids of the isolate were 16:0, 18:1 w9c, and 16:1 w7c/15 iso 2OH. The DNA base composition was 44 mol%. Phylogenetic analysis based on the 16S rRNA sequence revealed that the isolate formed an evolutionary lineage distinct from other Acinetobacter species. Based on the evaluation of morphologic, physiologic, and chemotaxonomic characteristics, DNA-DNA hybridization values, and 16S rRNA sequence comparison, we propose the new species Acinetobacter antiviralis sp. nov., the type strain of which is KNF2022T(=KCTC0699BPT).

Roles of reactive oxygen species in CXCL8 and CCL2 expression in response to the 30-kDa antigen of Mycobacterium tuberculosis.

BACKGROUND: The 30-kDa antigen (Ag) of Mycobacterium tuberculosis (M. tuberculosis) is a strong inducer of innate and adaptive immune responses in human tuberculosis. The generation of reactive oxygen species (ROS) plays an important role in inflammatory signaling as well as antimicrobial defense. MATERIALS AND METHODS: In this study, we investigated the role of ROS in the activation of mitogen-activated protein kinases (MAPKs) and secretion of the CXC chemokine ligand 8 (CXCL8) and CC chemokine ligand 2 (CCL2) by human monocytes stimulated with the 30-kDa Ag of M. tuberculosis H37Rv. RESULTS: Treatment of human monocytes with the 30-kDa Ag activated rapid superoxide generation. In addition, the 30-kDa Ag activated mRNA and protein expression of CXCL8 and CCL2 in human primary monocytes through nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-dependent ROS generation. Analysis of MAPK activation (extracellular signal-regulated kinase (ERK) 1/2 and p38) showed rapid phosphorylation of both subfamilies in response to the 30-kDa Ag. In addition, 30-kDa-induced MAPK activation was inhibited in a dose-dependent manner by pretreatment with ROS scavengers. Toll-like receptor (TLR) 2 was required for ROS generation, chemokine production, and MAPK activation following stimulation with the 30-kDa Ag. Using highly specific signaling pathway inhibitors, we found that both p38 and ERK1/2 activation are essential for 30-kDa Ag-induced CCL2 but not CXCL8 production in human monocytes. CONCLUSION: These results indicate that TLR2-ROS signaling plays a crucial role in the 30-kDa Ag-mediated expression of CXCL8 and CCL2 in human monocytes. In addition, both p38 and ERK1/2 activation are essential for 30-kDa Ag-stimulated CCL2 production by monocytes.

Macrophage inhibitory cytokine-1 activates AKT and ERK-1/2 via the transactivation of ErbB2 in human breast and gastric cancer cells.

Macrophage inhibitory cytokine-1 (MIC-1) is a member of the transforming growth factor-beta superfamily, which is overexpressed in a variety of human cancers, including breast and gastric cancer. The function of MIC-1 in cancer remains controversial and its signaling pathways remain poorly understood. In this study, we demonstrate that MIC-1 induces the transactivation of ErbB2 in SK-BR-3 breast and SNU-216 gastric cancer cells. MIC-1 induced a significant phosphorylation of Akt and ERK-1/2, and also effected an increase in the levels of tyrosine phosphorylation of ErbB1, ErbB2 and ErbB3 in SK-BR-3 and SNU-216 cells. The treatment of these cells with AG825 and AG1478, inhibitors specific for ErbB2 tyrosine kinase, resulted in the complete abolition of MIC-1-induced Akt and ERK-1/2 phosphorylation. Furthermore, the small-interfering RNA-mediated downregulation of ErbB2 significantly reduced not only the phosphorylation of Akt and ERK-1/2 but also the invasiveness of the cells induced by MIC-1. Our results show that ErbB2 activation performs a crucial function in MIC-1-induced signaling pathways. Further investigations revealed that MIC-1 induced the expression of the hypoxia inducible factor-1alpha protein and the expression of its target genes, including vascular endothelial growth factor, via the activation of the mammalian target of rapamycin (mTOR) signaling pathway. Stimulation of SK-BR-3 with MIC-1 profoundly induces the phosphorylation of mTOR and its downstream substrates, including p70S6K and 4E-BP1. Collectively, these results show that MIC-1 may participate in the malignant progression of certain human cancer cells that overexpress ErbB2 through the transactivation of ErbB2 tyrosine kinase.

Adipocyte culture medium stimulates production of macrophage inhibitory cytokine 1 in MDA-MB-231 cells.

Obesity is one of the potential risk factors in causing breast cancer. As a result, adipose tissue surrounding breast ductal cells may play an important role in the breast cancer development or progression. To identify the genes that are regulated by factors secreted from adipocytes in breast cancer cells, MDA-MB-231 cells were treated with the culture medium of adipocytes. Most of induced genes were related to immune function and wound healing, which share a common gene expression signature with cancer progression. In present study macrophage inhibitory cytokine 1 (MIC-1) gene was studied among the induced genes. It was found that both MIC-1 mRNA and protein were dramatically increased by the culture medium of adipocytes. Furthermore, proteinase K-treated adipocyte culture supernatants also induced MIC-1 expression. These findings indicate that proteins are not major MIC-1 inducing factors in adipocyte culture medium. Consequently, we examined the effect of free fatty acids such as palmitate and oleate on MIC-1 induction and found that palmitate markedly induced MIC-1 gene expression, whereas oleate did not. Adipocyte culture medium- and palmitate-induced MIC-1 gene expression was mediated by the activation of p38 MAPK, but not by the activation of JNK, ERK, and NF-kappaB pathway. In addition, adipocyte-CM-induced MIC-1 also increased invasiveness of MDA-MB-231 cells.

Halomonas gomseomensis sp. nov., Halomonas janggokensis sp. nov., Halomonas salaria sp. nov. and Halomonas denitrificans sp. nov., moderately halophilic bacteria isolated from saline water.

A total of 34 Halomonas strains were isolated from saline water in Anmyeondo, Korea. Ten of these strains, considered to belong to novel species, were subjected to a polyphasic taxonomic investigation. The strains were Gram-negative, moderately halophilic, motile and non-spore-forming rods that contained Q-9 as the predominant ubiquinone and C(18 : 1)omega7c, C(16 : 0) and either summed feature 4 (C(16 : 1)omega7c/C(15 : 0) iso 2-OH) or C(19 : 0) cyclo omega8c as the major fatty acids. Phylogenetic analysis, based on 16S rRNA gene sequencing, showed that the ten isolates formed four separate lineages in the genus Halomonas. Combined phenotypic data and DNA-DNA hybridization data supported the conclusion that they represent four novel species in the genus Halomonas, for which the names Halomonas gomseomensis sp. nov. (type strain M12(T)=KCTC 12662(T)=DSM 18042(T)), Halomonas janggokensis sp. nov. (type strain M24(T)=KCTC 12663(T)=DSM 18043(T)), Halomonas salaria sp. nov. (type strain M27(T)=KCTC 12664(T)=DSM 18044(T)) and Halomonas denitrificans sp. nov. (type strain M29(T)=KCTC 12665(T)=DSM 18045(T)) are proposed.

Chryseobacterium caeni sp. nov., isolated from bioreactor sludge.

A Gram-negative, non-spore-forming, yellow-pigmented bacterium, strain N4(T), was isolated from a nickel-complexed cyanide-degrading bioreactor and subjected to a polyphasic taxonomic study. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain N4(T) is affiliated to the genus Chryseobacterium of the family Flavobacteriaceae. The levels of 16S rRNA gene sequence similarity between strain N4(T) and the type strains of all known Chryseobacterium species were 93.2-95.8 %, suggesting that strain N4(T) represents a novel species within the genus Chryseobacterium. The strain contained iso-C(15 : 0) and summed feature 4 as the major fatty acids and menaquinone MK-6 as the predominant respiratory quinone. The G+C content of the genomic DNA was 38.2 mol%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain N4(T) represents a novel species of the genus Chryseobacterium, for which the name Chryseobacterium caeni sp. nov. is proposed. The type strain is N4(T) (=KCTC 12506(T)=CCBAU 10201(T)=DSM 17710(T)).

Transfer of Chryseobacterium meningosepticum and Chryseobacterium miricola to Elizabethkingia gen. nov. as Elizabethkingia meningoseptica comb. nov. and Elizabethkingia miricola comb. nov.

The taxonomic positions of six strains (including the type strain) of Chryseobacterium meningosepticum (King 1959) Vandamme et al. 1994 and the type strain of Chryseobacterium miricola Li et al. 2004 were re-evaluated by using a polyphasic taxonomic approach. Phylogenetic analysis, based on 16S rRNA gene sequencing, showed that the strains represent a separate lineage from the type strains of the Chryseobacterium-Bergeyella-Riemerella branch within the family Flavobacteriaceae (90.7-93.9 % similarities), which was supported by phenotypic differences. Combined phylogenetic and phenotypic data showed that C. meningosepticum and C. miricola should be transferred to a new genus, Elizabethkingia gen. nov., with the names Elizabethkingia meningoseptica comb. nov. (type strain, ATCC 13253(T) = NCTC 10016(T) = LMG 12279(T) = CCUG 214(T)) and Elizabethkingia miricola comb. nov. (type strain, DSM 14571(T) = JCM 11413(T) = GTC 862(T)) proposed.