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1.
Microb Drug Resist ; 25(3): 317-325, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30864883

RESUMO

Development of antibiotic resistance can be achieved either by mutation or by acquiring a resistance gene from foreign sources, with some resistance genes likely originating in microbial populations to counteract antibiotics present in natural ecosystems. In this study, we describe the first report of a strain of nonclinical multidrug-resistant Stenotrophomonas sp. strain G4 with high-level resistance to colistin and meropenem, phylogenetically distinct from well-studied multiple drug-resistant species of Stenotrophomonas maltophilia. As the high-level colistin resistance of this strain was of great concern, the genome of this strain was completely sequenced. Only one chromosome was identified, and no plasmids were found. Chromosomal gene variants and other potential genetic determinants conferring resistance to colistin and meropenem were comparatively analyzed, and results showed that strain G4 harbored two putative colistin resistance determinants (named mcr-5.3 and mcr-8.2) and four extended-spectrum ß-lactamase genes. In addition, 12 genes potentially encoding seven different types of efflux pumps were identified, which may have a major role in acquisition/transfer of colistin resistance. Our discovery of multiple antibiotic resistance determinants in this environmental strain extensively expands our understanding of the extent of dissemination of colistin and meropenem resistance.


Assuntos
Colistina/farmacologia , Farmacorresistência Bacteriana/genética , Meropeném/farmacologia , Esgotos/microbiologia , Stenotrophomonas maltophilia/efeitos dos fármacos , Stenotrophomonas maltophilia/isolamento & purificação , Antibacterianos/farmacologia , Stenotrophomonas maltophilia/genética , Água , Microbiologia da Água , beta-Lactamases/genética
2.
Mol Microbiol ; 112(1): 29-46, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30927282

RESUMO

In Streptomyces, GlnR is an activator protein that activates nitrogen-assimilation genes under nitrogen-limiting conditions. However, less is known regarding the regulation of these genes under nitrogen-rich conditions. We determined that the developmental regulator MtrA represses nitrogen-assimilation genes in nitrogen-rich media and that it competes with GlnR for binding to GlnR boxes. The GlnR boxes upstream of multiple nitrogen genes, such as amtB, were confirmed as MtrA binding sites in vitro by electrophoretic mobility shift assays and in vivo by ChIP-qPCR analysis. Transcriptional analysis indicated that, on nutrient-rich medium, MtrA profoundly repressed expression of nitrogen-associated genes, indicating opposing roles for MtrA and GlnR in the control of nitrogen metabolism. Using in vitro and in vivo analysis, we also showed that glnR is itself a direct target of MtrA and that MtrA represses glnR transcription. We further demonstrated functional conservation of MtrA homologues in the recognition of GlnR boxes upstream of nitrogen genes from different actinobacterial species. As mtrA and glnR are widespread among actinomycetes, this mechanism of potential competitive control over nitrogen metabolism genes may be common in this group, adding a major new layer of complexity to the known regulatory network for nitrogen metabolism in Streptomyces and related species.

3.
Appl Environ Microbiol ; 85(4)2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30530707

RESUMO

As with most annotated two-component systems (TCSs) of Streptomyces coelicolor, the function of TCS SCO2120/2121 was unknown. Based on our findings, we have designated this TCS MacRS, for morphogenesis and actinorhodin regulator/sensor. Our study indicated that either single or double mutation of MacRS largely blocked production of actinorhodin but enhanced formation of aerial mycelium. Chromatin immunoprecipitation (ChIP) sequencing, using an S. coelicolor strain expressing MacR-Flag fusion protein, identified in vivo targets of MacR, and DNase I footprinting of these targets revealed a consensus sequence for MacR binding, TGAGTACnnGTACTCA, containing two 7-bp inverted repeats. A genome-wide search revealed sites identical or highly similar to this consensus sequence upstream of six genes encoding putative membrane proteins or lipoproteins. These predicted sites were confirmed as MacR binding sites by DNase I footprinting and electrophoretic mobility shift assays in vitro and by ChIP-quantitative PCR in vivo, and transcriptional analyses demonstrated that MacR significantly impacts expression of these target genes. Disruption of three of these genes, sco6728, sco4924, and sco4011, markedly accelerated aerial mycelium formation, indicating that their gene products are novel morphogenic factors. Two-hybrid assays indicated that these three proteins, which we have named morphogenic membrane protein A (MmpA; SCO6728), MmpB (SCO4924), and MmpC (SCO4011), interact with one another and with the putative membrane protein and MacR target SCO4225. Notably, SAV6081/82 and SVEN1780/81, homologs of MacRS TCS from S. avermitilis and S. venezuelae, respectively, can substitute for MacRS, indicating functional conservation. Our findings reveal a role for MacRS in cellular morphogenesis and secondary metabolism in Streptomyces IMPORTANCE TCSs help bacteria adapt to environmental stresses by altering gene expression. However, the roles and corresponding regulatory mechanisms of most TCSs in the Streptomyces model strain S. coelicolor are unknown. We investigated the previously uncharacterized MacRS TCS and identified the core DNA recognition sequence, two seven-nucleotide inverted repeats, for the DNA-binding protein MacR. We further found that MacR directly controls a group of membrane proteins, including MmpA-C, which are novel morphogenic factors that delay formation of aerial mycelium. We also discovered that these membrane proteins interact with one another and that other Streptomyces species have conserved MacRS homologs. Our findings suggest a conserved role for MacRS in morphogenesis and/or other membrane-associated activities. Additionally, our study showed that MacRS impacts, albeit indirectly, the production of the signature metabolite actinorhodin, further suggesting that MacRS and its homologs function as novel pleiotropic regulatory systems in Streptomyces.

4.
3 Biotech ; 8(11): 472, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30456006

RESUMO

Mobile genetic elements involved in mediating horizontal transfer events contribute to bacterial evolution, and bacterial genomic plasticity and instability result in variation in functional genetic information in Streptomyces secondary metabolism. In a previous study, we reported the complete genome sequence of the industrial Streptomyces strain F613-1, which produces high yields of clavulanic acid. In this study, we used comparative genomics and bioinformatics to investigate the unique genomic features of this strain. Taken together, comparative genomics were used to systematically investigate secondary metabolism capabilities and indicated that frequent exchange of genetic materials between Streptomyces replicons may shape the remarkable diversities in their secondary metabolite repertoires. Moreover, a 136.9-kb giant region of plasticity (RGP) was found in the F613-1 chromosome, and the chromosome and plasmid pSCL4 are densely packed with an exceptionally large variety of potential secondary metabolic gene clusters, involving several determinants putatively accounting for antibiotic production. In addition, the differences in the architecture and size of plasmid pSCL4 between F613-1 and ATCC 27064 suggest that the pSCL4 plasmid could evolve from pSCL4-like and pSCL2-like extrachromosomal replicons. Furthermore, the genomic analyses revealed that strain F613-1 has developed specific genomic architectures and genetic patterns that are well suited to meet the requirements of industrial innovation processes.

5.
Tuberculosis (Edinb) ; 112: 62-68, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30205970

RESUMO

MprAB and PhoPR are important two-component systems (TCSs) in Mycobacterium tuberculosis, and both regulate EspR, a key regulator of the ESX-1 secretion system. Although previous studies suggest that the response regulator PhoP does not directly regulate mprA, the interplay between MprAB and PhoPR remains unclear. In this study, we found that the response regulator MprA can bind to the phoP promoter. Four repeat motifs, D1-D4, constituting two predicted binding sites, were located in the region protected by MprA in DNA footprinting. D1-D4 lack the reported conserved MprA binding sequences, indicating that MprA can recognize a greater range of target sites. Interestingly, D1-D2 overlap a previously reported PhoP binding site, and mutation of D1-D2 inhibited PhoP binding, whereas the D3-D4 site, but not the D1-D2 site, was required for MprA binding. EMSA assays also suggest that MprA and PhoP compete to bind to the phoP promoter. The results of the transcriptional and western blot assays are consistent with a model in which MprA positively controls the phoP expression, which in turn upregulates the expression of espR. These findings reveal complex regulation of a major mycobacterial TCS by dual TCSs.

6.
FEMS Microbiol Lett ; 365(17)2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29931327

RESUMO

The genome of Streptomyces coelicolor encodes hundreds of putative regulatory proteins, most of which are of unknown function, including SCO5351. In this study, we determined that deletion of sco5351 largely abrogates production of actinorhodin (ACT) and reduces production of the calcium-dependent antibiotic (CDA). Comprehensive transcriptional analyses indicated that transcription of genes of the ACT pathway, including the pathway-specific regulator actII-orf4 and those involved in the building of the chemical compound, was markedly lower in Δsco5351 in the late growth phase. However, transcription of genes in the CDA cluster was notably reduced in Δsco5351 only in the early growth phase, suggesting that SCO5351 has a regulatory role throughout growth. Similar to the observations with Δsco5351, ACT production was blocked by mutagenesis of three conserved amino acids potentially involved in dimerization of SCO5351, indicating that protein dimerization is critical to the function of SCO5351. In addition, disruption of sco5351 delayed the formation of aerial mycelium and spores under the conditions tested and, consistent with this, transcription of developmental genes associated with spore formation was reduced in Δsco5351, implying that SCO5351 is involved in developmental control. Our findings reveal SCO5351 as a pleiotropic regulator with roles in both secondary metabolism and morphological development in S. coelicolor.

7.
Curr Microbiol ; 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29858620

RESUMO

Ansamitocins are extraordinarily potent antitumor agents. Ansamitocin P-3 (AP-3), which is produced by Actinosynnema pretiosum, has been developed as a cytotoxic drug for breast cancer. Despite its importance, AP-3 is of limited applicability because of the low production yield. A. pretiosum strain X47 was developed from A. pretiosum ATCC 31565 by mutation breeding and shows a relatively high AP-3 yield. Here, we analyzed the A. pretiosum X47 genome, which is ~8.13 Mb in length with 6693 coding sequences, 58 tRNA genes, and 15 rRNA genes. The DNA sequence of the ansamitocin biosynthetic gene cluster is highly similar to that of the corresponding cluster in A. pretiosum ATCC 31565, with 99.9% identity. However, RT-qPCR analysis showed that the expression levels of ansamitocin biosynthetic genes were significantly increased in X47 compared with the levels in the wild-type strain, consistent with the higher yield of AP-3 in X47. The annotated complete genome sequence of this strain will facilitate understanding the molecular mechanisms of ansamitocin biosynthesis and regulation in A. pretiosum and help further genetic engineering studies to enhance the production of AP-3.

8.
FEMS Microbiol Lett ; 365(6)2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29481594

RESUMO

The ability of Microlunatus phosphovorus to accumulate large amounts of polyphosphate (Poly-P) plays an important role in removing soluble phosphorus from wastewater. Strain JN459, isolated from a sewage system, was previously demonstrated to be Microlunatus phosphovorus. In this study, we analyzed the phosphorus-accumulating and phosphorus-releasing characteristics of strain JN459. Our analyses indicate that strain JN459 accumulates Poly-P under aerobic conditions but releases phosphorus under anaerobic conditions. To determine the mechanisms underlying Poly-P metabolism in strain JN459, we compared transcriptional profiles under aerobic and anaerobic conditions. Significant differences were detected in the expression levels of genes associated with Poly-P metabolism between aerobic and anaerobic conditions, including ppk (MLP_47700, MLP_50300 and MLP_05750), ppgk (MLP_05430 and MLP_26610), ppx (MLP_44770), pap (MLP_23310) and ppnk (MLP_17420). The high expression of polyphosphate glucokinase (MLP_05430) and polyphosphate/ATP-dependent NAD kinase (MLP_17420) indicated that both of them might be responsible for utilizing Poly-P as the energy resource for growth under anaerobic conditions. These findings enhance our understanding of phosphate metabolism in a major bacterial species involved in wastewater phosphorus reduction.

9.
Genome Announc ; 6(1)2018 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-29301883

RESUMO

Streptomyces gilvosporeus strain F607 is a producer of high levels of natamycin used in the fermentation industry. In this study, the complete genome sequence of strain F607 was determined. This genome sequence provides a basis for understanding natamycin biosynthesis and regulation in a high-natamycin-producing strain and will aid in the development of useful strategies for improving industrial strains.

10.
Curr Microbiol ; 75(4): 401-409, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29134265

RESUMO

Rv1057 is the only ß-propeller protein in Mycobacterium tuberculosis, but its biological function is still unclear. In this study, we generated a deletion mutant of Rv1057 (D1057) in the virulent M. tuberculosis strain H37Rv and examined the characteristics of the mutant in vitro and in macrophages. We found that deletion of Rv1057 reduces secretion of the major virulence factor ESAT-6 and ESAT-6 stops in the cell envelope fraction during secretion, although ESAT-6 levels were similar in lysates of the mutant and control strains. In infected macrophages, Rv1057 deletion significantly reduced the secretion levels of cytokines IL-1ß, IL-10, TNF-α, and INF-γ, but did not affect IL-4 and IL-8. D1057-infected macrophages also release less LDH and produce more nitric oxide (NO) than H37Rv- and D1057com (Rv1057 complemented strain of D1057com)-infected macrophages, indicating that D1057 has the decreased cytotoxicity compared to H37Rv or D1057com. In addition, the capacity of the Rv1057 deletion mutant to grow in macrophages was significantly lower than that of H37Rv and D1057com. Our findings support a role for Rv1057 in ESAT-6 secretion and in modulating the interactions between M. tuberculosis and macrophages.


Assuntos
Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Mycobacterium tuberculosis/crescimento & desenvolvimento , Mycobacterium tuberculosis/genética , Tuberculose/microbiologia , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Células Cultivadas , Deleção de Genes , Humanos , Interleucina-10/genética , Interleucina-10/metabolismo , Interleucina-4/genética , Interleucina-4/metabolismo , Macrófagos/metabolismo , Macrófagos/microbiologia , Mycobacterium tuberculosis/metabolismo , Óxido Nítrico/metabolismo , Tuberculose/genética , Tuberculose/metabolismo , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
11.
Can J Microbiol ; 64(1): 87-90, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29073359

RESUMO

Enterobacter cloacae strain R11 is a multidrug-resistant bacterium isolated from sewage water near a swine feedlot in China. Strain R11 can survive in medium containing up to 192 µg/mL polymyxin E, indicating a tolerance for this antibiotic that is significantly higher than that reported for other gram-negative bacteria. In this study, conjugation experiments showed that partial polymyxin E resistance could be transferred from strain R11 to Escherichia coli strain 25922, revealing that some genes related to polymyxin E resistance are plasmid-based. The complete genome sequence of this strain was determined, yielding a total of 4 993 008 bp (G+C content, 53.15%) and 4908 genes for the circular chromosome and 4 circular plasmids. Genome analysis revealed a total of 73 putative antibiotic resistance genes, including several polymyxin E resistance genes and genes potentially involved in multidrug resistance. These data provide insights into the genetic basis of the polymyxin E resistance and multidrug resistance of E. cloacae.


Assuntos
Farmacorresistência Bacteriana/genética , Enterobacter cloacae/genética , Genoma Bacteriano/genética , China , Resistência a Múltiplos Medicamentos/genética , Plasmídeos/genética
12.
Front Microbiol ; 8: 2013, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29085353

RESUMO

The developmental life cycle of Streptomyces species includes aerial hyphae formation and spore maturation, two distinct developmental processes that are controlled, respectively, by two families of developmental regulatory genes, bld and whi. In this study, we show that the response regulator MtrA (SCO3013) is critical for normal development of aerial hyphae in S. coelicolor and related species. ΔmtrA, a deletion mutant of the response regulator gene mtrA, exhibited the bald phenotype typical of bld mutants defective in aerial mycelium formation, with formation either much delayed or absent depending on the culture medium. Transcriptional analysis indicated that MtrA activates multiple genes involved in formation of aerial mycelium, including chp, rdl, and ram genes, as well as developmental regulatory genes of the bld and whi families. However, the major regulatory gene bldD showed enhanced expression in ΔmtrA, suggesting it is repressed by MtrA. electrophoretic mobility shift assays indicated that MtrA binds upstream of several genes with altered expression in ΔmtrA, including bldD and whiI, and sequences similar to the consensus binding sequence for MtrA of another actinomycete, Mycobacterium tuberculosis, were found in the bound sites. A loosely conserved recognition sequence containing two short, direct repeats was identified for MtrA of S. coelicolor and was validated using mutational analysis. MtrA homologs are widely distributed among Streptomyces species, and as with S. coelicolor, deletion of the mtrA homologs sve_2757 from S. venezuelae and sli_3357 from S. lividans resulted in conditional bald morphology. Our study suggests a critical and conserved role for MtrA in Streptomyces development.

13.
FEMS Microbiol Lett ; 364(22)2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29069461

RESUMO

The xdhR gene encodes a TetR-family regulator in Streptomyces coelicolor. However, little is known about the function of XdhR in regulating actinorhodin production. Here, we report that XdhR negatively regulates actinorhodin biosynthesis in S. coelicolor. Deletion of xdhR resulted in overproduction of actinorhodin by approximately 2.5-fold compared to the wild-type strain. Complementation of the xdhR deletion strain restored actinorhodin production to normal levels. In addition, the relative expression levels of actinorhodin cluster genes were all significantly increased in the xdhR deletion strain compared to the wild-type strain. XdhR can specifically bind the promoters of actII-4 and actII-1, two pathway-specific regulators of actinorhodin biosynthesis. These results suggest that xdhR negatively controls actinorhodin biosynthesis by directly regulating actII-4 and actII-1 in S. coelicolor.


Assuntos
Proteínas de Bactérias/genética , Streptomyces coelicolor/genética , Xantina Desidrogenase/genética , Antraquinonas/análise , Antraquinonas/metabolismo , Proteínas de Bactérias/metabolismo , Escherichia coli/genética , Deleção de Genes , Regulação Bacteriana da Expressão Gênica/genética , Genoma Bacteriano , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Streptomyces coelicolor/metabolismo , Xantina Desidrogenase/metabolismo
14.
Electron. j. biotechnol ; 28: 41-46, July. 2017. tab, ilus, graf
Artigo em Inglês | LILACS | ID: biblio-1015839

RESUMO

Background: Streptomyces clavuligerus was the producer of clavulanic acid, claR, a pathway-specific transcriptional regulator in S. clavuligerus, positively regulates clavulanic acid biosynthesis. In this study, the promoter-less kanamycin resistance gene neo was fused with claR to obtain strain NEO from S. clavuligerus F613-1. The claR-neo fusion strain NEO was mutated using physical and chemical mutagens and then screened under high concentrations of kanamycin for high-yield producers of clavulanic acid. Results: The reporter gene neo was fused downstream of claR and used as an indicator for expression levels of claR in strain NEO. After three rounds of continuous treatment and screening, the high-yield clavulanic acid-producing strain M3-19 was obtained. In the shaking flask model, the clavulanic acid titer of M3-19 reached 4.33 g/L, which is an increase of 33% over the titer of 3.26 g/L for the starting strains S. clavuligerus F613-1 and NEO. Conclusions: Our results indicate that neo can be effectively used as a reporter for the expression of late-stage biosynthetic genes when screening for high-yield strains and that this approach has strong potential for improving Streptomyces strains of industrial value.


Assuntos
Streptomyces/genética , Streptomyces/metabolismo , Canamicina , Ácido Clavulânico/biossíntese , Fatores de Transcrição/genética , Transcrição Genética , Bioensaio , Proteínas Recombinantes , Cromatografia Líquida de Alta Pressão , Mutagênese , Regiões Promotoras Genéticas , Genes Reporter , Fusão Gênica , Fermentação , Reação em Cadeia da Polimerase em Tempo Real
15.
Curr Microbiol ; 74(8): 979-986, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28585046

RESUMO

The genetics of the Streptomyces hygroscopicus strain 10-22 is of interest due to the ability of this strain to produce antifungal compounds. Strain T110 was obtained through insertional mutagenesis of strain 10-22 and was found to have undergone DNA amplification, as determined by both conventional and pulsed-field gel electrophoresis (PFGE). pIJ702, the vector used for insertional mutagenesis, was shown to have integrated into and co-amplified with the chromosomal DNA sequence of T110, as pIJ702 hybridized predominantly with two of the three amplified BamHI fragments. The amplified DNA sequence in T110 is 10.8 kb in length and consists of 5.18 kb of Streptomyces chromosomal DNA and the entire 5.62 kb pIJ702 sequence. Sequence analysis of the 5.18 kb chromosomal sequence revealed two open reading frames, one encoding a putative IS5 family transposase and the other encoding a putative dihydroxy-acid dehydratase. Real-time PCR analysis showed that expression of the putative dehydratase gene in T110 is about 50 times greater than in the wild-type strain, consistent with the high level of amplification of this DNA region, and therefore this system has the potential for producing economically or clinically important molecules.


Assuntos
Expressão Gênica , Genes Bacterianos , Streptomyces/genética , Cromossomos Bacterianos , Perfilação da Expressão Gênica , Vetores Genéticos , Mutagênese Insercional , Reação em Cadeia da Polimerase em Tempo Real , Recombinação Genética , Análise de Sequência de DNA
16.
Genom Data ; 12: 116-117, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28491497

RESUMO

The complete genome sequence of Streptomyces violaceus strain S21, a valuable natural compounds producer isolated from the forest soil, is firstly presented here. The genome comprised 7.91M bp, with a G + C content of 72.65%. A range of genes involved in pathways of secondary product biosynthesis were predicted. The genome sequence is available at DDBJ/EMBL/Genbank under the accession number CP020570. This genome is annotated with 6856 predicted genes identifying the natural product biosynthetic gene clusters in S. violaceus.

17.
Genome Announc ; 5(20)2017 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-28522727

RESUMO

Streptomyces tsukubaensis strain F601 was found to be a producer of the immunosuppressive drug tacrolimus. The draft genome sequence of this strain was approximately 8.52 Mbp. Genes involved in the biosynthesis of tacrolimus were identified in the genome. This draft genome sequence will provide insights into the genetic basis of tacrolimus biosynthesis and regulation.

18.
Genome Announc ; 5(3)2017 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-28104659

RESUMO

Here, we report the complete genome sequence of the triclosan- and multidrug-resistant Pseudomonas aeruginosa strain B10W, obtained from municipal wastewater in Hawaii. The bacterium has a 6.7-Mb genome, contains 6,391 coding sequences and 78 RNAs, with an average G+C content of 66.2 mol%.

19.
Braz. J. Pharm. Sci. (Online) ; 53(4): e17081, 2017. tab, graf, ilus
Artigo em Inglês | LILACS | ID: biblio-889411

RESUMO

ABSTRACT Heparin-SOD conjugate (Hep-SOD) was prepared by modifying Cu,Zn-SOD with heparin. An acute radiation-induced mouse injury model was constructed to study the radiation protection effects of Hep-SOD conjugate. Fifty-six mice were randomly divided into seven groups: (I) normal control group; (II) irradiated control group; (III) positive control group (amifostine group, 300 mg/kg); (IV) SOD group (35000 U/kg); (V) high dosage of Hep-SOD group (70000 U/kg); (VI) medium dosage of Hep-SOD group (35000 U/kg); (VII) low dosage of Hep-SOD group (17500 U/kg). Drugs were intraperitoneally injected into each mouse 1 h before radiation except for the normal control group. All the irradiated groups were irradiated with 6 Gy. Organ indices, haematopoietic function indices, peripheral blood cells, liver function test, oxidative stress state and pathological observation were detected to study the effects of Hep-SOD on irradiated mice. Results showed that bone marrow suppression of irradiated mice could be reduced when treated by Hep-SOD before radiation. Oxidative stress detection and pathological observation of the liver and intestine showed that the damage caused by radiation was relieved when mice were treated with Hep-SOD before radiation. This study shows a new direction to prevent organisms from the damage caused by radiation.


Assuntos
Animais , Masculino , Ratos , Superóxido Dismutase , Heparina , Liberação Nociva de Radioativos , Radiação/classificação , Anormalidades Induzidas por Radiação , Estresse Oxidativo/efeitos da radiação
20.
Genome Announc ; 4(5)2016 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-27660792

RESUMO

Streptomyces clavuligerus strain F613-1 is an industrial strain with high-yield clavulanic acid production. In this study, the complete genome sequence of S. clavuligerus strain F613-1 was determined, including one linear chromosome and one linear plasmid, carrying numerous sets of genes involving in the biosynthesis of clavulanic acid.

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