An essential role for NOD1 in host recognition of bacterial peptidoglycan containing diaminopimelic acid

Nucleotide-binding oligomerization domain protein 1 (NOD1) belongs to a family that includes multiple members with NOD and leucine-rich repeats in vertebrates and plants. NOD1 has been suggested to have a role in innate immune responses, but the mechanism involved remains unknown. Here we report that NOD1 mediates the recognition of peptidoglycan derived primarily from Gram-negative bacteria. Biochemical and functional analyses using highly purified and synthetic compounds indicate that the core structure recognized by NOD1 is a dipeptide, gamma-D-glutamyl-meso-diaminopimelic acid (iE-DAP). Murine macrophages deficient in NOD1 did not secrete cytokines in response to synthetic iE-DAP and did not prime the lipopolysaccharide response. Thus, NOD1 mediates selective recognition of bacteria through detection of iE-DAP-containing peptidoglycan.

Bacillus pallidus sp nov., isolated from forest soil

A Gram-positive bacterium, designated strain CW 7(T), was isolated from forest soil in Anhui Province, south-east China. Cells were strictly aerobic, motile with peritrichous flagella and rod-shaped. The strain grew optimally at 30-37 degrees C and pH 7.0-8.0. The major fatty acids of strain CW 7(T) were anteiso-C-15:0, iso-C-15:0 and anteiso-C-17:0. The predominant menaquinone was MK-7. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The G + C content of the genomic DNA was 42.3 mol%. Phylogenetic analysis indicated that strain CW 7(T) belonged to a monophyletic cluster within the genus Bacillus and showed 16S rRNA gene sequence similarities of less than 96.5% to recognized species of the genus Bacillus. The results of the polyphasic taxonomic study, including phenotypic, chemotaxonomic and phylogenetic analyses, showed that strain CW 7(T) represents a novel species of the genus Bacillus, for which the name Bacillus pallidus sp. nov. is proposed. The type strain is CW 7(T) (=KCTC 13200(T)=CCTCC AB 207188(T)=LMG 24451(T)).

Jiangella gansuensis gen. nov., sp nov., a novel actinomycete from a desert soil in north-west China

A novel actinomycete strain, designated YIM 002(T), was isolated from a desert soil sample in Gansu Province, north-west China. This actinomycete isolate formed well-differentiated aerial and substrate mycelia. In the early stages of growth, the substrate mycelia fragmented into short or elongated rods. Chemotaxonomically, it contained LL-2,6-diaminopimelic acid in the cell wall. The cell-wall sugars contained ribose and glucose. Phospholipids present were phosphatidylinositol mannosides, phosphatidylinositol and diphosphatidylglycerol. MK-9(H-4) was the predominant menaquinone. The major fatty acids were anteiso C-15:0 (35.92%), anteiso C-17:0 (15.84%), iso C-15:0 (10.40%), iso C-16:0 (7.07%) and C(17:10)w8c (9.37%). The G+C content of the DNA was 70 mol%. Phylogenetic analysis and signature nucleotide data based on 16S rRNA gene sequences showed that strain YIM 002(T) is distinct from all recognized genera of the family Nocardioidaceae in the suborder Propionibacterineae. On the basis of the phenotypic and genotypic characteristics, it is proposed that isolate YIM 002(T) be classified as a novel species in a new genus, Jiangella gansuensis gen. nov., sp. nov. The type strain is YIM 002(T) (= DSM 44835(T) = CCTCC AA 204001(T) = KCTC 19044(T)).

Kroppenstedtia pulmonis sp. nov. and Kroppenstedtia sanguinis sp. nov., isolated from human patients

Three human clinical strains (W9323T , X0209T and X0394) isolated from lung biopsy, blood and cerebral spinal fluid, respectively, were characterized using a polyphasic taxonomic approach. Comparative analysis of the 16S rRNA gene sequences showed the three strains belonged to two novel branches within the genus Kroppenstedtia : 16S rRNA gene sequence analysis of W9323T showed closest sequence similarity to Kroppenstedtia eburnea JFMB- ATET (95.3 %), Kroppenstedtia guangzhouensis GD02T (94.7 %) and strain X0209T (94.6 %); sequence analysis of strain X0209T showed closest sequence similarity to K . eburnea JFMB- ATET (96.4 %) and K. guangzhouensis GD02T (96.0 %). Strains X0209T and X0394 were 99.9 % similar to each other by 16S rRNA gene sequence analysis. The DNA- DNA relatedness was 94.6 %, confirming that X0209T and X0394 belong to the same species. Chemotaxonomic data for strains W9323T and X0209T were consistent with those described for the genus Kroppenstedtia : whole- cell peptidoglycan contained LL- diaminopimelic acid; the major cellular fatty acids were iso- C15 and anteiso- C15 ; and the major menaquinone was MK- 7. Different endospore morphology, carbon utilization profiles, and whole cell wall sugar patterns of strains W9323T and X0209T supported by phylogenetic analysis enabled us to conclude that the strains represent two new species within the genus Kroppenstedtia , for which the names Kroppenstedtia pulmonis sp. nov. (type strain W9323T = DSM 45752T = CCUG 68107T) and Kroppenstedtia sanguinis sp. nov. (type strain X0209T = DSM 45749T = CCUG 38657T) are proposed.

Disassembly of a Medial Transenvelope Structure by Antibiotics during Intracellular Division.

Chlamydiales possess a minimal but functional peptidoglycan precursor biosynthetic and remodeling pathway involved in the assembly of the division septum by an atypical cytokinetic machine and cryptic or modified peptidoglycan-like structure (PGLS). How this reduced cytokinetic machine collectively coordinates the invagination of the envelope has not yet been explored in Chlamydiales. In other Gram-negative bacteria, peptidoglycan provides anchor points that connect the outer membrane to the peptidoglycan during constriction using the Pal-Tol complex. Purifying PGLS and associated proteins from the chlamydial pathogen Waddlia chondrophila, we unearthed the Pal protein as a peptidoglycan-binding protein that localizes to the chlamydial division septum along with other components of the Pal-Tol complex. Together, our PGLS characterization and peptidoglycan-binding assays support the notion that diaminopimelic acid is an important determinant recruiting Pal to the division plane to coordinate the invagination of all envelope layers with the conserved Pal-Tol complex, even during osmotically protected intracellular growth.

Corynebacterium atypicum sp. nov., from a human clinical source, does not contain corynomycolic acids

An unusual Gram-positive, facultatively anaerobic, catalase-positive, diphtheroid-shaped organism originating from an unknown human clinical source was characterized by biochemical, molecular chemical and molecular phylogenetic methods. Based on its morphological and biochemical characteristics and the presence of a murein based on meso-diaminopimelic acid, the unidentified organism was tentatively assigned to the genus Corynebacterium. However, the unknown organism was found to lack the distinctive, short-chain corynomycolic acids that are considered to be characteristic of this genus. Despite the absence of these characteristic lipids, comparative 16S rRNA gene sequencing showed that the unknown bacterium was phylogenetically a member of the genus Corynebacterium and was distinct from all currently known species. Based on both phenotypic and 16S rRNA sequence considerations, it is proposed that the unknown organism be classified as a novel species, Corynebacterium atypicum sp. nov. The type strain of C. atypicum is strain R2070(T) (= CCUG 45804(T) = CIP 107431(T)).

Corynebacterium sphenisci sp nov., isolated from wild penguins

Six unidentified Gram-positive, rod-shaped organisms recovered from the cloacae of apparently healthy wild penguins were characterized by phenotypic and molecular taxonomic methods. Chemotaxonomic investigations revealed the presence of a cell wall based on meso-diaminopimelic acid and long-chain cellular fatty acids of the straight-chain saturated and monounsaturated types, consistent with the genus Corynebacterium. Corynomycolic acids, which are characteristic of the genus, were also detected, albeit in small amounts. Comparative 16S rRNA gene sequencing studies showed that the unidentified organisms were phylogenetically related to corynebacteria and represent a novel subline associated with a small subcluster of species that includes Corynebacterium xerosis, Corynebacterium amycolatum and Corynebacterium freneyi. The unknown isolates were readily distinguished from their closest phylogenetic relatives and all other Corynebacterium species with validly published names by using a combination of biochemical and chemotaxonomic criteria. Based on both phenotypic and 16S rRNA gene sequence considerations, it is proposed that the unknown isolates recovered from penguins be classified as a novel species in the genus Corynebacterium, Corynebacterium sphenisci sp. nov. The type strain is CECT 5990(T) (= CCUG 46398(T)).

Arsenicicoccus bolidensis gen. nov., sp. nov., a novel actinomycete isolated from contaminated lake sediment

An unknown Gram-positive, catalase-positive, facultatively anaerobic, non-spore-forming, coccus-shaped bacterium originating from sediment was characterized using phenotypic, molecular chemical and molecular phylogenetic methods. Chemical studies revealed the presence of a cell-wall murein based on LL-diaminopimelic acid (type LL-Dpm-glycine(1)), a complex mixture of saturated, monounsaturated and iso- and anteiso-methyl-branched, non-hydroxylated, long-chain cellular fatty acids and tetrahydrogenated menaquinones with eight isoprene units [MK-8(H-4)] as the major respiratory lipoquinone. This combination of characteristics somewhat resembled members of the suborder Micrococcineae, but did not correspond to any currently described species. Comparative 16S rRNA gene sequencing confirmed that the unidentified coccus-shaped organism is a member of the Actinobacteria and represents a hitherto-unknown subline related to, albeit different from, a number of taxa including Intrasporangium, Janibacter, Terrabacter, Terracoccus and Ornithinicoccus. Based on phenotypic and phylogenetic considerations, it is proposed that the unknown bacterium originating from lake sediment be classified as a new genus and species, Arsenicicoccus bolidensis gen. nov., sp. nov. (type strain CCUG 47306(T) = DSM 15745(T)).

Antibiotic 26-deoxylaidlomycin isolated from Streptomyces sp. Ar386 from Brazilian soil

An actinomycete strain (Ar386) was isolated from the soil of the Araraquara regio, SP, Brazil. The strain, named Streptomyces jacareensis, formed irregular rayed, rugose, grayish-white mycelium with sinuous, branched hyphae carrying rare isolated spores; assimilated glucose, galactose, inositol, ribose, maltose, sucrose, melibiose and starch but not mannitol, rhamnose, arabinose, xylose, lactose and raffinose; and contained LL- diaminopimelic acid in its cell wall. An antibiotic active against Gram- positive bacteria, which was characterized as being 26-deoxylaidlomycin and which may have application against poultry coccidiosis, was isolated from cultures of the strain. This was the first isolation of this antibiotic from a microorganism of the genus Streptomyces and also the first isolation of this antibiotic in Brazil.

Obtenção de mutantes de Streptomyces clavuligerus e avaliação de condições de cultivo para a melhoria de produção de cefamicina C

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)