Project description:We report the draft genome sequence of Nocardia seriolae strain N-2927 (NBRC 110360), isolated from cultured yellowtail Seriola quinqueradiata. RAST annotation of the genome revealed 117 genes involved in the virulence, disease, and defense subsystem. Eleven of these genes were predicted as antibiotic resistance genes.
Project description:In Japan, the emergence of macrolide- and oxytetracycline-resistant strains of Nocardia seriolae has previously been reported. Here, we describe the draft genome sequence of N. seriolae strain U-1, isolated in 2011 from a diseased yellowtail in Kagoshima Prefecture. The draft genome does not have any genes responsible for macrolide and tetracycline resistance.
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:Nocardiosis caused by Nocardia seriolae is one of the major threats in the aquaculture of Seriola species (yellowtail; S. quinqueradiata, amberjack; S. dumerili and kingfish; S. lalandi) in Japan. Here, we report the complete nucleotide genome sequence of N. seriolae UTF1, isolated from a cultured yellowtail. The genome is a circular chromosome of 8,121,733 bp with a G+C content of 68.1% that encodes 7,697 predicted proteins. In the N. seriolae UTF1 predicted genes, we found orthologs of virulence factors of pathogenic mycobacteria and human clinical Nocardia isolates involved in host cell invasion, modulation of phagocyte function and survival inside the macrophages. The virulence factor candidates provide an essential basis for understanding their pathogenic mechanisms at the molecular level by the fish nocardiosis research community in future studies. We also found many potential antibiotic resistance genes on the N. seriolae UTF1 chromosome. Comparative analysis with the four existing complete genomes, N. farcinica IFM 10152, N. brasiliensis HUJEG-1 and N. cyriacigeorgica GUH-2 and N. nova SH22a, revealed that 2,745 orthologous genes were present in all five Nocardia genomes (core genes) and 1,982 genes were unique to N. seriolae UTF1. In particular, the N. seriolae UTF1 genome contains a greater number of mobile elements and genes of unknown function that comprise the differences in structure and gene content from the other Nocardia genomes. In addition, a lot of the N. seriolae UTF1-specific genes were assigned to the ABC transport system. Because of limited resources in ocean environments, these N. seriolae UTF1 specific ABC transporters might facilitate adaptation strategies essential for marine environment survival. Thus, the availability of the complete N. seriolae UTF1 genome sequence will provide a valuable resource for comparative genomic studies of N. seriolae isolates, as well as provide new insights into the ecological and functional diversity of the genus Nocardia.
Project description:Nocardia seriolae is a pathogen that causes nocardiosis in marine and freshwater fish. Here, we report the draft genome sequence of N. seriolae strain ZJ0503, which was isolated from Trachinotus ovatus in Guangdong, China.
Project description:Largemouth bass (Micropterus salmoides) are common hosts of an epizootic bacterial infection by Nocardia seriolae. We conducted transcriptome profiling of M. salmoides to understand the host immune response to N. seriolae infection, using the Illumina sequencing platform. De novo assembly of paired-end reads yielded 47,881 unigenes, the total length, average length, N50, and GC content of which were 49,734,288, 1038, 1983 bp, and 45.94%, respectively. Annotation was performed by comparison against non-redundant protein sequence (NR), non-redundant nucleotide (NT), Swiss-Prot, Clusters of Orthologous Groups (COG), Kyoto Encyclopaedia of Genes and Genomes (KEGG), Gene Ontology (GO), and Interpro databases, yielding 28,964 (NR: 60.49%), 36,686 (NT: 76.62%), 24,830 (Swissprot: 51.86%), 8913 (COG: 18.61%), 20,329 (KEGG: 42.46%), 835 (GO: 1.74%), and 22,194 (Interpro: 46.35%) unigenes. Additionally, 8913 unigenes were classified into 25 Clusters of Orthologous Groups (KOGs) categories, and 20,329 unigenes were assigned to 244 specific signalling pathways. RNA-Seq by Expectation Maximization (RSEM) and PossionDis were used to determine significantly differentially expressed genes (False Discovery Rate (FDR) < 0.05) and we found that 1384 were upregulated genes and 1542 were downregulated genes, and further confirmed their regulations using reverse transcription quantitative PCR (RT-qPCR). Altogether, these results provide information on immune mechanisms induced during bacterial infection in largemouth bass, which may facilitate the prevention of nocardiosis.
Project description:Strains 335427T and 234509T, isolated from two 76-year-old patients with chronic pulmonary diseases, were the subject of polyphasic taxonomic studies and comparative genomic analyses for virulence factors. The 16 rRNA gene sequence similarity between strains 335427T and 234509T and their closest phylogenetic neighbors Nocardia asiatica NBRC 100129T and Nocardia abscessus NBRC 100374T were 99.5% and 100%, respectively. Digital DNA-DNA hybridization values between the aforementioned studied strains were well below the 70% threshold for assigning prokaryotic strains to a novel species. Strains 335427T and 234509T have genome sizes of 8.49 Mpb and 8.07 Mpb, respectively, with G + C content of 68.5%. Isolate 335427T has C16:0, C18:1 ?9c, C18:0 and C18:0 10 methyl as major fatty acids (>15%) and mycolic acids formed of 52-54 carbon atoms. However, only C18:1 ?9c was detected for isolate 234509T, which had mycolic acids with 44-56 carbon. Based on phenotypic and genetic data, strains 335427T (DSM 109819T = CECT 9924T) and 234509T (DSM 111366T = CECT 30129T) merit recognition as novel species, which are named Nocardia barduliensis sp. nov. and Nocardia gipuzkoensis sp. nov., respectively. All the strains studied had homologous VF-associated genes to those described in M. tuberculosis, including experimentally verified virulence genes in humans related to tuberculosis. The narGHIJ (nitrate reduction pathway) and gvpAFGOJLMK (gas vesicles) genetic maps of strains 335427T, 234509T, NBRC 100129T and NBRC 100374T showed the same syntenic block and raise the question of whether their functions are interlinked during the infection of the human host. However, further research is required to decipher the role of the gas vesicle in the pathogenicity mechanism of Nocardia spp.