Project description:We report four draft genome sequences of Nocardia spp. The strains are the Nocardia cyriacigeorgica DSM 44484 pathogenic type strain; two environmental isolates, Nocardia cyriacigeorgica EML446 and EML1456; and the Nocardia asteroides ATCC 19247 nonpathogenic type strain, with estimated genome sizes of 6.3 to 6.8?Mb. The study of these isolates will provide insight into physiology, evolution, and pathogenicity of Nocardia spp.
Project description:Nocardia sp. strain CS682 is a rare actinobacterium with a promising ability to produce secondary metabolites such as nargenicin A1 (an effective antibacterial compound) and IBR-3 (a UV-protectant molecule). Here, we report the complete genome sequence of Nocardia sp. CS682, obtained by PacBio sequencing as a single contig with 8,919,230?bp (GC content, 63.3%).
Project description:<i>Nocardia wallacei</i> is one of the members of the <i>N. transvalensis</i> complex which possess a highly unique susceptibility pattern. Here, we describe the closed complete genome sequence of the multidrug-resistant strain <i>N. wallacei</i> FMUON74, which was obtained using a hybrid approach combining Nanopore long-read sequencing and Illumina and DNBseq short-read sequencing.
Project description:"Nocardia suismassiliense" strain S-137 isolated from Sus scrofa feces exhibits a 9.4-Mb (67.1% GC content) draft genome sequence containing 8,658 protein-coding genes, 66 tRNAs, and 9 rRNAs. In silico DNA-DNA hybridization confirmed strain S-137 as representative of a new species, "Nocardia suismassiliense," closely related to N. tenerifensis and N. brasiliensis.
Project description:We report two cases of Nocardia cyriacigeorgica septicemia and disseminated infection in the setting of profound immunodeficiency. In both instances, diagnosis was rapidly facilitated by 16S rRNA gene sequencing of blood culture isolates. These constitute the first confirmed reports of Nocardia cyriacigeorgica bloodstream infection in humans.
Project description:We report an improved de novo draft genome sequence of the human-pathogenic strain Nocardia terpenica IFM 0706T The resequencing unveiled that the genome size is larger than anticipated, reducing significantly the number of contigs and building a basis for comparison with the closely related strain N. terpenica IFM 0406.
Project description:Members of the genus Nocardia are widespread in diverse environments; a wide range of Nocardia species are known to cause nocardiosis in several animals, including cat, dog, fish, and humans. Of the pathogenic Nocardia species, N. seriolae is known to cause disease in cultured fish, resulting in major economic loss. We isolated two N. seriolae strains, CK-14008 and EM15050, from diseased fish and sequenced their genomes using the PacBio sequencing platform. To identify their genomic features, we compared their genomes with those of other Nocardia species. Phylogenetic analysis showed that N. seriolae shares a common ancestor with a putative human pathogenic Nocardia species. Moreover, N. seriolae strains were phylogenetically divided into four clusters according to host fish families. Through genome comparison, we observed that the putative pathogenic Nocardia strains had additional genes for iron acquisition. Dozens of antibiotic resistance genes were detected in the genomes of N. seriolae strains; most of the antibiotics were involved in the inhibition of the biosynthesis of proteins or cell walls. Our results demonstrated the virulence features and antibiotic resistance of fish pathogenic N. seriolae strains at the genomic level. These results may be useful to develop strategies for the prevention of fish nocardiosis.
Project description:Accurate identification of <i>Nocardia</i> species remains a challenge due to the complexities of taxonomy and insufficient discriminatory power of traditional techniques. We report the development of a molecular technique that utilizes real-time PCR-based high-resolution melting (HRM) analysis for differentiation of the most common <i>Nocardia</i> species. Based on a novel <i>fusA-tuf</i> intergenic region sequence, <i>Nocardia farcinica</i>, <i>Nocardia cyriacigeorgica</i> and <i>Nocardia beijingensis</i> were clearly distinguished from one another by HRM analysis. The limit of detection of the HRM assay for purified <i>Nocardia</i> spp. DNA was at least 10 fg. No false positives were observed for specificity testing of 20 non-target clinical samples. In comparison to established matrix-assisted laser desorption/ionization-time of flight MS, the HRM assay improved the identification of <i>N. beijingensis</i>. Additionally, all the products of PCR were verified by direct sequencing. In conclusion, the developed molecular assay allows simultaneous detection and differentiation of <i>N. farcinica</i>, <i>N. cyriacigeorgica</i> and <i>N. beijingensis</i> with high sensitivity and specificity.
Project description:BACKGROUND: Actinobacteria of the genus Nocardia usually live in soil or water and play saprophytic roles, but they also opportunistically infect the respiratory system, skin, and other organs of humans and animals. Primarily because of the clinical importance of the strains, some Nocardia genomes have been sequenced, and genome sequences have accumulated. Genome sizes of Nocardia strains are similar to those of Streptomyces strains, the producers of most antibiotics. In the present work, we compared secondary metabolite biosynthesis gene clusters of type-I polyketide synthase (PKS-I) and nonribosomal peptide synthetase (NRPS) among genomes of representative Nocardia species/strains based on domain organization and amino acid sequence homology. RESULTS: Draft genome sequences of Nocardia asteroides NBRC 15531(T), Nocardia otitidiscaviarum IFM 11049, Nocardia brasiliensis NBRC 14402(T), and N. brasiliensis IFM 10847 were read and compared with published complete genome sequences of Nocardia farcinica IFM 10152, Nocardia cyriacigeorgica GUH-2, and N. brasiliensis HUJEG-1. Genome sizes are as follows: N. farcinica, 6.0 Mb; N. cyriacigeorgica, 6.2 Mb; N. asteroides, 7.0 Mb; N. otitidiscaviarum, 7.8 Mb; and N. brasiliensis, 8.9 - 9.4 Mb. Predicted numbers of PKS-I, NRPS, and PKS-I/NRPS hybrid clusters ranged between 4-11, 7-13, and 1-6, respectively, depending on strains, and tended to increase with increasing genome size. Domain and module structures of representative or unique clusters are discussed in the text. CONCLUSION: We conclude the following: 1) genomes of Nocardia strains carry as many PKS-I and NRPS gene clusters as those of Streptomyces strains, 2) the number of PKS-I and NRPS gene clusters in Nocardia strains varies substantially depending on species, and N. brasiliensis strains carry the largest numbers of clusters among the species studied, 3) the seven Nocardia strains studied in the present work have seven common PKS-I and/or NRPS clusters, some of whose products are yet to be studied, and 4) different N. brasiliensis strains have some different gene clusters of PKS-I/NRPS, although the rest of the clusters are common within the N. brasiliensis strains. Genome sequencing suggested that Nocardia strains are highly promising resources in the search of novel secondary metabolites.
Project description:Sequence analysis of the Nocardia essential secretory protein SecA1 gene (secA1) for species identification of 120 American Type Culture Collection (ATCC) and clinical isolates of Nocardia (16 species) was studied in comparison with 5'-end 606-bp 16S rRNA gene sequencing. Species determination by both methods was concordant for all 10 ATCC strains. secA1 gene sequencing provided the same species identification as 16S rRNA gene analysis for 94/110 (85.5%) clinical isolates. However, 40 (42.6%) isolates had sequences with <99.0% similarity to archived secA1 sequences for the species, including 29 Nocardia cyriacigeorgica (96.6 to 98.9% similarity) and 4 Nocardia veterana (91.5 to 98.9% similarity) strains. Discrepant species identification was obtained for 16 (14.5%) clinical isolates, including 13/23 Nocardia nova strains (identified as various Nocardia species by secA1 sequencing) and 1 isolate each of Nocardia abscessus (identified as Nocardia asiatica), Nocardia elegans (Nocardia africana), and Nocardia transvalensis (Nocardia blacklockiae); both secA1 gene sequence analysis and deduced amino acid sequence analysis determined the species to be different from those assigned by 16S rRNA gene sequencing. The secA1 locus showed high sequence diversity (66 sequence or genetic types versus 40 16S rRNA gene sequence types), which was highest for N. nova (14 secA1 sequence types), followed by Nocardia farcinica and N. veterana (n = 7 each); there was only a single sequence type among eight Nocardia paucivorans strains. The secA1 locus has potential for species identification as an adjunct to 16S rRNA gene sequencing but requires additional deduced amino acid sequence analysis. It may be a suitable marker for phylogenetic/subtyping studies.