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Sample records for cavitada por rhodococcus

  1. Cloning systems for Rhodococcus and related bacteria

    DOEpatents

    Finnerty, W.R.; Singer, M.E.

    1990-08-28

    A plasmid transformation system for Rhodococcus was developed using an Escherichia coli-Rhodococcus shuttle plasmid. Rhodococcus sp. H13-A contains three cryptic indigenous plasmids, designated pMVS100, pMVS200 and pMVS300, of 75, 19.5 and 13.4 kilobases (Kb), respectively. A 3.8 Kb restriction fragment of pMVS300 was cloned into pIJ30, a 6.3 Kb pBR322 derivative, containing the E. coli origin of replication (ori) and ampicillin resistance determinant (bla) as well as a Streptomyces gene for thiostrepton resistance, tsr. The resulting 10.1 Kb recombinant plasmid, designated pMVS301, was isolated from E. coli DH1 (pMVS301) and transformed into Rhodococcus sp. AS-50, a derivative of strain H13-A, by polyethylene glycol-assisted transformation of Rhodococcus protoplasts and selection for thiostrepton-resistant transformants. This strain was deposited with the ATCC on Feb. 1, 1988 and assigned ATCC 53719. The plasmid contains the Rhodococcus origin of replication. The plasmid and derivatives thereof can therefore be used to introduce nucleic acid sequences to and from Rhodococcus for subsequent expression and translation into protein. The isolated origin of replication can also be used in the construction of new vectors. 2 figs.

  2. Cloning systems for Rhodococcus and related bacteria

    DOEpatents

    Finnerty, William R.; Singer, Mary E.

    1990-01-01

    A plasmid transformation system for Rhodococcus was developed using an Escherichia coli-Rhodococcus shuttle plasmid. Rhodococcus sp. H13-A contains three cryptic indigenous plasmids, designated pMVS100, pMVS200 and pMVS300, of 75, 19.5 and 13.4 kilobases (Kb), respectively. A 3.8 Kb restriction fragment of pMVS300 was cloned into pIJ30, a 6.3 Kb pBR322 derivative, containing the E. coli origin of replication (ori) and ampicillin resistance determinant (bla) as well as a Streptomyces gene for thiostrepton resistance, tsr. The resulting 10.1 Kb recombinant plasmid, designated pMVS301, was isolated from E. coli DH1 (pMVS301) and transformed into Rhodococcus sp. AS-50, a derivative of strain H13-A, by polyethylene glycol-assisted transformation of Rhodococcus protoplasts and selection for thiostrepton-resistant transformants. This strain was deposited with the ATCC on Feb. 1, 1988 and assigned ATCC 53719. The plasmid contains the Rhodococcus origin of replication. The plasmid and derivatives thereof can therefore be used to introduce nucleic acid sequences to and from Rhodococcus for subsequent expression and translation into protein. The isolated origin of replication can also be used in the construction of new vectors.

  3. Rhodococcus empyema in a heart transplant patient

    PubMed Central

    Rose, Richard; Nord, John; Lanspa, Michael

    2014-01-01

    Rhodococcus equi is a rare cause of pneumonia and empyema almost exclusively occurring in immunocompromised patients. Most people who become infected have direct exposure to livestock. We present a case where the exposure was presumed to be through a family member in close contact with horses. Our case describes an infection in a heart transplant patient that was initially identified as a probable intra-abdominal infection and later reidentified as Rhodococcus equi empyema, and was treated with surgery and prolonged antibiotics. PMID:25473561

  4. Construction of an Escherichia coli-rhodococcus shuttle vector and plasmid transformation in Rhodococcus spp

    SciTech Connect

    Singer, M.E.V.; Finnerty, W.R.

    1988-02-01

    A plasmid transformation system for Rhodococcus sp. strain H13-A was developed by using an Escherichia coli-Rhodococcus shuttle plasmid constructed in this study. Rhodococcus sp. strain H13-A contains three cryptic indigenous plasmids, designated pMVS100, pMVS200, and pMVS300, of 75, 19.5, and 13.4 kilobases (kb), respectively. A 3.8-kb restriction fragment of pMVS300 was cloned into pIJ30, a 6.3-kb pBR322 derivative, containing the E. coli origin of replication (ori) and ampicillin resistance determinant (bla), as well as a Streptomyces gene for thiostrepton resistance, tsr. The resulting 10.1-kb recombinant plasmid, designated pMVS301, was isolated from E. coli DH1 (pMVS301) and transformed into Rhodococccus sp. strain AS-50, a derivative of strain H13-A. The cloned 3.8-kb fragment of Rhodococcus DNA in pMVS301 contains a Rhodococcus origin of replication, since the hybrid plasmid was capable of replication in both genera. The plasmid was identical in E. coli and Rhodococcus transformants as determined by restriction analysis and was maintained as a stable, independent replicon in both organisms. A restriction map demonstrated 14 unique restriction sites in pMVS301, some of which are potentially useful for molecular cloning in Rhodococcus spp. and other actinomycetes. This is the first report of plasmid transformation and of heterologous gene expression in a Rhodococcus sp.

  5. Metabolism of 2-Mercaptobenzothiazole by Rhodococcus rhodochrous

    PubMed Central

    Haroune, Nicolas; Combourieu, Bruno; Besse, Pascale; Sancelme, Martine; Kloepfer, Achim; Reemtsma, Thorsten; De Wever, Heleen; Delort, Anne-Marie

    2004-01-01

    2-Mercaptobenzothiazole, which is mainly used in the rubber industry as a vulcanization accelerator, is very toxic and is considered to be recalcitrant. We show here for the first time that it can be biotransformed and partially mineralized by a pure-culture bacterial strain of Rhodococcus rhodochrous. Three metabolites, among four detected, were identified. PMID:15466583

  6. Growth of rhodococcus S1 on anthracene.

    PubMed

    Tongpim, S; Pickard, M A

    1996-03-01

    Three slow-growing bacteria were isolated from a mixed culture enriched for growth on anthracene, using creosote-contaminated soil as the inoculum. Organisms were shown to use anthracene by the production of a clear zone around the colony after a mineral salts agar plate was sprayed with anthracene. All three bacteria were nonmotile, nonsporulating, gram-positive rods and stained acid-fast. Physiological and biochemical tests, GC content, and cell wall lipid patterns of whole cell methanolysates indicated that they belonged to the Nocardia-Mycobacterium-Rhodococcus group. On the basis of these characteristics and pyrolysis gas chromatography, they were assigned to the genus Rhodococcus. Growth of the isolates was slow on crystalline anthracene, giving a doubling time of 1.5-3 days, and they grew mainly on the crystal surface. When anthracene was supplied by precipitation from a solvent, doubling time was reduced to 1 day. All three isolates mineralized anthracene but not phenanthrene or naphthalene, nor could they grow on naphthalene, phenanthrene, fluorene, fluoranthene, acenaphthene, pyrene, chrysene, or naphthacene as sole carbon source. One isolate, Rhodococcus S1, was able to use 2-methylanthracene or 2-chloroanthracene as carbon source but not 1- or 9-substituted analogs. These results suggest that the initial enzyme attacking anthracene in these isolates has a narrow substrate specificity. PMID:8868237

  7. Draft Genome Sequence of Rhodococcus sp. Strain 311R

    PubMed Central

    Ehsani, Elham; Jauregui, Ruy; Geffers, Robert; Jareck, Michael; Boon, Nico; Pieper, Dietmar H.

    2015-01-01

    Here, we report the draft genome sequence of Rhodococcus sp. strain 311R, which was isolated from a site contaminated with alkanes and aromatic compounds. Strain 311R shares 90% of the genome of Rhodococcus erythropolis SK121, which is the closest related bacteria. PMID:25999565

  8. Rhodococcus enclensis sp. nov., a novel member of the genus Rhodococcus.

    PubMed

    Dastager, Syed G; Mawlankar, Rahul; Tang, Shan-Kun; Krishnamurthi, Srinivasan; Ramana, V Venkata; Joseph, Neeta; Shouche, Yogesh S

    2014-08-01

    A novel actinobacterial strain, designated, NIO-1009(T), was isolated from a marine sediment sample collected from Chorao Island, Goa, India. Phylogenetic analysis comparisons based on 16S rRNA gene sequences between strain NIO-1009(T) and other members of the genus Rhodococcus revealed that strain NIO-1009(T) had the closest sequence similarity to Rhodococcus kroppenstedtii DSM 44908(T) and Rhodococcus corynebacterioides DSM 20151(T) with 99.2 and 99.1%, respectively. Furthermore, DNA-DNA hybridization results showed that R. kroppenstedtii DSM 44908(T) and R. corynebacterioides DSM 20151(T) were 39.5 (3.0%) and 41.7 (2.0%) with strain NIO-1009(T), respectively, which were well below the 70% limit for any novel species proposal. Phylogenetically strain NIO-1009(T) forms a stable clade with and R. kroppenstedtii DSM 44908(T) and R. corynebacterioides DSM 20151(T) with 100% bootstrap values. Strain NIO-1009(T) contained meso-diaminopimelic acid as the diagnostic diamino acid and galactose and arabinose as the cell wall sugars. The major fatty acids were C(16 : 0), C(18 : 1)ω9c, C(16 : 1)(ω6c and/or ω7c) and 10-methyl C(18 : 0). The only menaquinone detected was MK-8(H2), while the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and one unknown phospholipid. The G+C content of the genomic DNA was 66.9 mol%. The phenotypic and genotypic data showed that strain NIO-1009(T) warrants recognition as a novel species of the genus Rhodococcus for which the name Rhodococcus enclensis sp. nov., is proposed; the type strain is NIO-1009(T) ( = NCIM 5452(T) = DSM 45688(T)). PMID:24854006

  9. Rhodococcus equi: clinical manifestations, virulence, and immunity.

    PubMed

    Giguère, S; Cohen, N D; Chaffin, M Keith; Hines, S A; Hondalus, M K; Prescott, J F; Slovis, N M

    2011-01-01

    Pneumonia is a major cause of disease and death in foals. Rhodococcus equi, a gram-positive facultative intracellular pathogen, is a common cause of pneumonia in foals. This article reviews the clinical manifestations of infection caused by R. equi in foals and summarizes current knowledge regarding mechanisms of virulence of, and immunity to, R. equi. A complementary consensus statement providing recommendations for the diagnosis, treatment, control, and prevention of infections caused by R. equi in foals can be found in the same issue of the Journal. PMID:22092609

  10. Draft genome sequence of Rhodococcus rhodochrous strain ATCC 17895

    PubMed Central

    Chen, Bi-Shuang; Otten, Linda G.; Resch, Verena; Muyzer, Gerard; Hanefeld, Ulf

    2013-01-01

    Rhodococcus rhodochrous ATCC 17895 possesses an array of mono- and dioxygenases, as well as hydratases, which makes it an interesting organism for biocatalysis. R. rhodochrous is a Gram-positive aerobic bacterium with a rod-like morphology. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 6,869,887 bp long genome contains 6,609 protein-coding genes and 53 RNA genes. Based on small subunit rRNA analysis, the strain is more likely to be a strain of Rhodococcus erythropolis rather than Rhodococcus rhodochrous. PMID:24501654

  11. Use of whole genome sequences to develop a molecular phylogenetic framework for Rhodococcus fascians and the Rhodococcus genus

    PubMed Central

    Creason, Allison L.; Davis, Edward W.; Putnam, Melodie L.; Vandeputte, Olivier M.; Chang, Jeff H.

    2014-01-01

    The accurate diagnosis of diseases caused by pathogenic bacteria requires a stable species classification. Rhodococcus fascians is the only documented member of its ill-defined genus that is capable of causing disease on a wide range of agriculturally important plants. Comparisons of genome sequences generated from isolates of Rhodococcus associated with diseased plants revealed a level of genetic diversity consistent with them representing multiple species. To test this, we generated a tree based on more than 1700 homologous sequences from plant-associated isolates of Rhodococcus, and obtained support from additional approaches that measure and cluster based on genome similarities. Results were consistent in supporting the definition of new Rhodococcus species within clades containing phytopathogenic members. We also used the genome sequences, along with other rhodococcal genome sequences to construct a molecular phylogenetic tree as a framework for resolving the Rhodococcus genus. Results indicated that Rhodococcus has the potential for having 20 species and also confirmed a need to revisit the taxonomic groupings within Rhodococcus. PMID:25237311

  12. Rhodococcus aerolatus sp. nov., isolated from subarctic rainwater.

    PubMed

    Hwang, C Y; Lee, I; Cho, Y; Lee, Y M; Baek, K; Jung, Y-J; Yang, Y Y; Lee, T; Rhee, T S; Lee, H K

    2015-02-01

    A Gram-stain-positive, rod-shaped and non-motile strain, designated PAMC 27367(T), was isolated from rainwater collected on the Bering Sea. Analysis of the 16S rRNA gene sequence of the strain showed an affiliation with the genus Rhodococcus. Phylogenetic analyses revealed that strain PAMC 27367(T) formed a robust clade with the type strains of Rhodococcus rhodnii, Rhodococcus aetherivorans and Rhodococcus ruber with 16S rRNA gene sequence similarities of 96.3 %, 95.8 % and 95.5 %, respectively. Cells of the strain grew optimally at 25 °C and at pH 6.5-7.0 in the presence of 0-2 % (w/v) sea salts. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and three unknown phospholipids. The major cellular fatty acids (>10 %) were iso-C16 : 0, C17 : 1ω8c and 10-methyl C17 : 0. Cell wall analysis showed that strain PAMC 27367(T) contained meso-diaminopimelic acid. The genomic DNA G+C content was 77.1 mol%. Based on the phylogenetic, chemotaxonomic and phenotypic data presented here, we propose a novel species with the name Rhodococcus aerolatus sp. nov., with PAMC 27367(T) ( = KCTC 29240(T) = JCM 19485(T)) as the type strain. PMID:25385992

  13. Spheroplast formation and plasmid isolation from Rhodococcus spp.

    PubMed

    Assaf, N A; Dick, W A

    1993-12-01

    The genus Rhodococcus comprises aerobic gram-positive actinomycetes that show considerable morphological and metabolic diversity and are known to be involved in the development of plant diseases and degradation of environmental pollutants. We describe a method for cell lysis and large plasmid DNA isolation from Rhodococcus by creating lysozyme susceptible cells by predigestion with the enzyme mutanolysin. Mutanolysin action resulted in the liberation of reducing sugars and free amino acids from the peptidoglycan layers of the cell wall. A 1-h predigestion with mutanolysin followed by a 0.5-h incubation with lysozyme resulted in spheroplast formation. Complete lysis of cells and efficient isolation of intact large plasmid DNA (108 kb) from wild-type Rhodococcus strains was confirmed. PMID:8292332

  14. Rhodococcus equi: an animal and human pathogen.

    PubMed Central

    Prescott, J F

    1991-01-01

    Recent isolations of Rhodococcus equi from cavitatory pulmonary disease in patients with AIDS have aroused interest among medical microbiologists in this unusual organism. Earlier isolations from humans had also been in immunosuppressed patients following hemolymphatic tumors or renal transplantation. This organism has been recognized for many years as a cause of a serious pyogranulomatous pneumonia of young foals and is occasionally isolated from granulomatous lesions in several other species, in some cases following immunosuppression. The last decade has seen many advances in understanding of the epidemiology, pathogenesis, diagnosis, treatment, and immunity to infection in foals. The particular susceptibility of the foal is not understood but can be explained in part by a combination of heavy challenge through the respiratory route coinciding with declining maternally derived antibody in the absence of fully competent foal cellular immune mechanisms. R. equi is largely a soil organism but is widespread in the feces of herbivores. Its growth in soil is considerably improved by simple nutrients it obtains from herbivore manure. About one-third of human patients who have developed R. equi infections had contact in some way with herbivores or their manure. Others may have acquired infection from contact with soil or wild bird manure. R. equi is an intracellular parasite, which explains the typical pyogranulomatous nature of R. equi infections, the predisposition to infection in human patients with defective cell-mediated immune mechanisms, and the efficacy of antimicrobial drugs that penetrate phagocytic cells. Images PMID:2004346

  15. Rhodococcus Bacteremia in Cancer Patients Is Mostly Catheter Related and Associated with Biofilm Formation

    PubMed Central

    Al Akhrass, Fadi; Al Wohoush, Iba; Chaftari, Anne-Marie; Reitzel, Ruth; Jiang, Ying; Ghannoum, Mahmoud; Tarrand, Jeffrey; Hachem, Ray; Raad, Issam

    2012-01-01

    Rhodococcus is an emerging cause of opportunistic infection in immunocompromised patients, most commonly causing cavitary pneumonia. It has rarely been reported as a cause of isolated bacteremia. However, the relationship between bacteremia and central venous catheter is unknown. Between 2002 and 2010, the characteristics and outcomes of seventeen cancer patients with Rhodococcus bacteremia and indwelling central venous catheters were evaluated. Rhodococcus bacteremias were for the most part (94%) central line-associated bloodstream infection (CLABSI). Most of the bacteremia isolates were Rhodococcus equi (82%). Rhodococcus isolates formed heavy microbial biofilm on the surface of polyurethane catheters, which was reduced completely or partially by antimicrobial lock solution. All CLABSI patients had successful response to catheter removal and antimicrobial therapy. Rhodococcus species should be added to the list of biofilm forming organisms in immunocompromised hosts and most of the Rhodococcus bacteremias in cancer patients are central line associated. PMID:22427914

  16. Draft Genome Sequence of Rhodococcus rhodochrous Strain ATCC 21198

    SciTech Connect

    Shields-Menard, Sara A.; Brown, Steven D; Klingeman, Dawn Marie; Indest, Karl; Hancock, Dawn; Wewalwela, Jayani; French, Todd; Donaldson, Janet

    2014-01-01

    Rhodococcus rhodochrous is a Gram-positive red-pigmented bacterium commonly found in the soil. The draft genome sequence for R. rhodochrous strain ATCC 21198 is presented here to provide genetic data for a better understanding of its lipid-accumulating capabilities.

  17. Complete Genome and Plasmid Sequences for Rhodococcus fascians D188 and Draft Sequences for Rhodococcus Isolates PBTS 1 and PBTS 2

    PubMed Central

    Stamler, Rio A.; Vereecke, Danny; Zhang, Yucheng; Schilkey, Faye; Devitt, Nico

    2016-01-01

    Rhodococcus fascians, a phytopathogen that alters plant development, inflicts significant losses in plant production around the world. We report here the complete genome sequence of R. fascians D188, a well-characterized model isolate, and Rhodococcus species PBTS (pistachio bushy top syndrome) 1 and 2, which were shown to be responsible for a disease outbreak in pistachios. PMID:27284129

  18. Complete Genome and Plasmid Sequences for Rhodococcus fascians D188 and Draft Sequences for Rhodococcus Isolates PBTS 1 and PBTS 2.

    PubMed

    Stamler, Rio A; Vereecke, Danny; Zhang, Yucheng; Schilkey, Faye; Devitt, Nico; Randall, Jennifer J

    2016-01-01

    Rhodococcus fascians, a phytopathogen that alters plant development, inflicts significant losses in plant production around the world. We report here the complete genome sequence of R. fascians D188, a well-characterized model isolate, and Rhodococcus species PBTS (pistachio bushy top syndrome) 1 and 2, which were shown to be responsible for a disease outbreak in pistachios. PMID:27284129

  19. Classification of strain CCM 4446T as Rhodococcus degradans sp. nov.

    PubMed

    Švec, Pavel; Černohlávková, Jitka; Busse, Hans-Jürgen; Vojtková, Hana; Pantůček, Roman; Cnockaert, Margo; Mašlaňová, Ivana; Králová, Stanislava; Vandamme, Peter; Sedláček, Ivo

    2015-12-01

    Strain CCM 4446T, with notable biodegradation capabilities, was investigated in this study in order to elucidate its taxonomic position. Chemotaxonomic analyses of quinones, polar lipids, mycolic acids, polyamines and the diamino acid of the cell-wall peptidoglycan corresponded with characteristics of the genus Rhodococcus. Phylogenetic analysis, based on the 16S rRNA gene sequence, assigned strain CCM 4446T to the genus Rhodococcus and placed it in the Rhodococcus erythropolis 16S rRNA gene clade. Further analysis of catA and gyrB gene sequences, automated ribotyping with EcoRI restriction endonuclease, whole-cell protein profiling, DNA-DNA hybridization and extensive biotyping enabled differentiation of strain CCM 4446T from all phylogenetically closely related species, i.e., Rhodococcus baikonurensis, Rhodococcus qingshengii, Rhodococcus erythropolis and Rhodococcus globerulus. The results obtained show that the strain investigated represents a novel species within the genus Rhodococcus, for which the name Rhodococcus degradans sp. nov., is proposed. The type strain is CCM 4446T ( = LMG 28633T). PMID:26385412

  20. Molecular biological enhancement of coal biodesulfurization. [Rhodococcus rhodochrous

    SciTech Connect

    Kilbane, J.J.; Bielaga, B.A.

    1990-07-01

    The overall objective of this project is to sue molecular genetics to develop strains of bacteria with enhanced ability to remove sulfur from coal and to obtain data that will allow the performance and economics of a coal biodesulfurization process to be predicted. The work planned for the current quarter (May 1990 to July 1990) includes the following activities: (1) Construct a cloning vector that can be used in Rhodococcus rhodochrous IGTS8 from the small cryptic plasmid found in Rhodococcus rhodochrous ATCC 190607; (2) Develop techniques for the genetic analysis of IGTS8; (3) Continue biochemical experiments, particularly those that may allow the identification of desulfurization-related enzymes; (4) Continue experiments with coal to determine the kinetics of organic sulfur removal.

  1. Rhodococcus equi (Prescottella equi) vaccines; the future of vaccine development.

    PubMed

    Giles, C; Vanniasinkam, T; Ndi, S; Barton, M D

    2015-09-01

    For decades researchers have been targeting prevention of Rhodococcus equi (Rhodococcus hoagui/Prescottella equi) by vaccination and the horse breeding industry has supported the ongoing efforts by researchers to develop a safe and cost effective vaccine to prevent disease in foals. Traditional vaccines including live, killed and attenuated (physical and chemical) vaccines have proved to be ineffective and more modern molecular-based vaccines including the DNA plasmid, genetically attenuated and subunit vaccines have provided inadequate protection of foals. Newer, bacterial vector vaccines have recently shown promise for R. equi in the mouse model. This article describes the findings of key research in R. equi vaccine development and looks at alternative methods that may potentially be utilised. PMID:24945608

  2. Degradation of estrogens by Rhodococcus zopfii and Rhodococcus equi isolates from activated sludge in wastewater treatment plants.

    PubMed

    Yoshimoto, Takeshi; Nagai, Fumiko; Fujimoto, Junji; Watanabe, Koichi; Mizukoshi, Harumi; Makino, Takashi; Kimura, Kazumasa; Saino, Hideyuki; Sawada, Haruji; Omura, Hiroshi

    2004-09-01

    We have isolated four strains of Rhodococcus which specifically degrade estrogens by using enrichment culture of activated sludge from wastewater treatment plants. Strain Y 50158, identified as Rhodococcus zopfii, completely and rapidly degraded 100 mg of 17beta-estradiol, estrone, estriol, and ethinyl estradiol/liter, as demonstrated by thin-layer chromatography and gas chromatography-mass spectrometry analyses. Strains Y 50155, Y 50156, and Y 50157, identified as Rhodococcus equi, showed degradation activities comparable with that of Y 50158. Using the random amplified polymorphism DNA fingerprinting test, these three strains were confirmed to have been derived from different sources. R. zopfii Y 50158, which showed the highest activity among these four strains, revealed that the strain selectively degraded 17beta-estradiol during jar fermentation, even when glucose was used as a readily utilizable carbon source in the culture medium. Measurement of estrogenic activities with human breast cancer-derived MVLN cells showed that these four strains each degraded 100 mg of 17beta-estradiol/liter to 1/100 of the specific activity level after 24 h. It is thus suggested that these strains degrade 17beta-estradiol into substances without estrogenic activity. PMID:15345411

  3. Genome Sequence of the Quorum-Quenching Rhodococcus erythropolis Strain R138

    PubMed Central

    Kwasiborski, Anthony; Mondy, Samuel; Beury-Cirou, Amélie

    2014-01-01

    Rhodococcus erythropolis strain R138 was isolated from the rhizosphere of Solanum tuberosum and selected for its capacity to degrade N-acyl-homoserine lactones, quorum-sensing signals used as communication molecules by the potato pathogens Pectobacterium and Dickeya. Here, we report the genome sequence of Rhodococcus erythropolis strain R138. PMID:24675862

  4. Rhodococcus equi Infection after Alemtuzumab Therapy for T-cell Prolymphocytic Leukemia

    PubMed Central

    Sprenger, Herman G.; van Assen, Sander; Leduc, Dominique; Daenen, Simon M.G.J.; Arends, Jan P.; van der Werf, Tjip S.

    2007-01-01

    Rhodococcus equi, mainly known from veterinary medicine as a pathogen in domestic animals, can also cause infections in immunocompromised humans, especially in those with defects in cellular immunity. Alemtuzumab, an anti-CD52 monoclonal antibody, causes lymphocytopenia by eliminating CD52-positive cells. We report a patient in whom Rhodococcus equi infection developed after alemtuzumab therapy. PMID:18258054

  5. Complete Genome Sequence of a Rhodococcus Species Isolated from the Winter Skate Leucoraja ocellata

    PubMed Central

    Wiens, Julia; Ho, Ryan; Fernando, Dinesh; Kumar, Ayush; Loewen, Peter C.; Anderson, W. Gary

    2016-01-01

    We report here a genome sequence for Rhodococcus sp. isolate UM008 isolated from the renal/interrenal tissue of the winter skate Leucoraja ocellata. Genome sequence analysis suggests that Rhodococcus bacteria may act in a novel mutualistic relationship with their elasmobranch host, serving as biocatalysts in the steroidogenic pathway of 1α-hydroxycorticosterone. PMID:27587827

  6. Complete Genome Sequence of a Rhodococcus Species Isolated from the Winter Skate Leucoraja ocellata.

    PubMed

    Wiens, Julia; Ho, Ryan; Fernando, Dinesh; Kumar, Ayush; Loewen, Peter C; Brassinga, Ann Karen C; Anderson, W Gary

    2016-01-01

    We report here a genome sequence for Rhodococcus sp. isolate UM008 isolated from the renal/interrenal tissue of the winter skate Leucoraja ocellata Genome sequence analysis suggests that Rhodococcus bacteria may act in a novel mutualistic relationship with their elasmobranch host, serving as biocatalysts in the steroidogenic pathway of 1α-hydroxycorticosterone. PMID:27587827

  7. Rhodococcus biphenylivorans sp. nov., a polychlorinated biphenyl-degrading bacterium.

    PubMed

    Su, Xiaomei; Liu, Yindong; Hashmi, Muhammad Zaffar; Hu, Jinxing; Ding, Linxian; Wu, Min; Shen, Chaofeng

    2015-01-01

    A Gram-positive, aerobic, non-motile and rod-coccus shaped novel actinobacterial strain, designated as TG9(T), was isolated from a polychlorinated biphenyl (PCB)-contaminated sediment in Taizhou city, Zhejiang province, eastern China. The isolate was observed to grow at 10-45 °C (optimum 28-32 °C), pH 5.0-11.0 (optimum pH 7.0-8.0) and with 0-9.0 % (w/v) NaCl (optimum 0-3.0 %). Comparison of the 16S rRNA gene sequences of strain TG9(T) and other members of the genus Rhodococcus showed that strain TG9(T) shared highest similarities with Rhodococcus pyridinivorans DSM 44555(T) (99.4 %), R. rhodochrous DSM 43241(T) (99.2 %), R. gordoniae DSM 44689(T) (99.2 %) and R. artemisiae DSM 45380(T) (98.2 %). However, low levels of DNA-DNA relatedness (15-48 %), which are below the 70 % limit for prokaryotic species identification, were obtained by DNA-DNA hybridization. Strain TG9(T) was found to contain meso-diaminopimelic acid as the diagnostic diamino acid and arabinose and galactose in the whole-cell hydrolysate. Mycolic acids were found to be present. The major fatty acids were identified as C16:0, C16:1 ω7c and/or iso-C15:0 2-OH, 10-methyl C18:0 and C18:1 ω9c. The only menaquinone detected was MK-8 (H2). The major polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, glycolipid and traces of some unknown lipids. The genomic DNA G+C content of strain TG9(T) was determined to be 62.8 %. The combined phenotypic and genotypic data show that the strain represents a novel species of the genus Rhodococcus for which the name Rhodococcus biphenylivorans sp. nov. is proposed, with the type strain TG9(T) (=CGMCC 1.12975(T) = KCTC 29673(T) = MCCC 1K00286(T)). PMID:25315102

  8. Survival and replication of Rhodococcus equi in macrophages.

    PubMed Central

    Hondalus, M K; Mosser, D M

    1994-01-01

    Rhodococcus equi is a facultative intracellular bacterium of macrophages that can cause serious pneumonia in both young horses and immunocompromised people. Essential to understanding rhodococcus pathogenesis is a quantitative documentation of the intracellular events that follow macrophage phagocytosis of the organism. By using a bacterial immunofluorescence staining assay, we verified the intracellular survival and replicative potential of R. equi in both murine peritoneal macrophages and equine alveolar macrophages in vitro. Following an initial lag period of 6 to 12 h, the intracellular numbers of R. equi begin to rise, often reaching macrophage-compromising levels by 48 h. A quantitative determination of bacterial growth by a novel image analysis cytometry technique confirmed our fluorescence microscopic results. By 48 h postinfection, bacterial numbers had increased by more than fivefold, and the majority of infected macrophages in the monolayer contained 10 or more bacteria per cell. The intracellular organisms were viable, as evidenced by the ability to incorporate radiolabeled uracil. The use of these techniques has identified differences in the in vitro replicative capacities of a virulent strain and an avirulent strain of R. equi. A clinical isolate of R. equi expressing a 17-kDa virulence-associated plasmid-encoded antigen was able to survive and replicate within macrophages, whereas an avirulent, non-plasmid-containing strain replicated poorly. These results suggest that plasmid-encoded bacterial virulence factors may contribute to the ability of R. equi to replicate within its host cell, the macrophage. Images PMID:7927672

  9. Draft Genome of Rhodococcus rhodochrous TRN7, Isolated from the Coast of Trindade Island, Brazil.

    PubMed

    Rodrigues, Edmo M; Pylro, Victor S; Dobbler, Priscila T; Victoria, Filipe; Roesch, Luiz F W; Tótola, Marcos R

    2016-01-01

    Here, we present a draft genome and annotation of Rhodococcus rhodochrous TRN7, isolated from Trindade Island, Brazil, which will provide genetic data to benefit the understanding of its metabolism. PMID:26941155

  10. Draft Genome of Rhodococcus rhodochrous TRN7, Isolated from the Coast of Trindade Island, Brazil

    PubMed Central

    Rodrigues, Edmo M.; Pylro, Victor S.; Dobbler, Priscila T.; Victoria, Filipe

    2016-01-01

    Here, we present a draft genome and annotation of Rhodococcus rhodochrous TRN7, isolated from Trindade Island, Brazil, which will provide genetic data to benefit the understanding of its metabolism. PMID:26941155

  11. Genome Sequence of Rhodococcus sp. Strain BCP1, a Biodegrader of Alkanes and Chlorinated Compounds

    PubMed Central

    Cappelletti, M.; Di Gennaro, P.; D’Ursi, P.; Orro, A.; Mezzelani, A.; Landini, M.; Fedi, S.; Frascari, D.; Presentato, A.; Milanesi, L.

    2013-01-01

    Rhodococcus sp. strain BCP1 cometabolizes chlorinated compounds and mineralizes a broad range of alkanes, as it is highly tolerant to them. The high-quality draft genome sequence of Rhodococcus sp. strain BCP1, consisting of 6,231,823 bp, with a G+C content of 70.4%, 5,902 protein-coding genes, and 58 RNA genes, is presented here. PMID:24158549

  12. Rhodococcus baikonurensis BTM4c, a boron-tolerant actinobacterial strain isolated from soil.

    PubMed

    Yoon, Jaewoo; Miwa, Hiroki; Ahmed, Iftikhar; Yokota, Akira; Fujiwara, Toru

    2010-01-01

    By screening a bacterial population from the soil in Tokyo, Japan, we isolated a boron-tolerant bacterium, strain BTM4c. Strain BTM4c grew under the boron excess conditions with 100 mM boric acid, which is generally toxic to bacteria. Molecular phylogenetic, chemotaxonomic, and physiological data showed that the strain belongs to the genus Rhodococcus, and is to be identified as Rhodococcus baikonurensis. PMID:20057133

  13. Genome and Phenotype Microarray Analyses of Rhodococcus sp. BCP1 and Rhodococcus opacus R7: Genetic Determinants and Metabolic Abilities with Environmental Relevance

    PubMed Central

    D’Ursi, Pasqualina; Milanesi, Luciano; Di Canito, Alessandra; Zampolli, Jessica; Collina, Elena; Decorosi, Francesca; Viti, Carlo; Fedi, Stefano; Presentato, Alessandro; Zannoni, Davide; Di Gennaro, Patrizia

    2015-01-01

    In this paper comparative genome and phenotype microarray analyses of Rhodococcus sp. BCP1 and Rhodococcus opacus R7 were performed. Rhodococcus sp. BCP1 was selected for its ability to grow on short-chain n-alkanes and R. opacus R7 was isolated for its ability to grow on naphthalene and on o-xylene. Results of genome comparison, including BCP1, R7, along with other Rhodococcus reference strains, showed that at least 30% of the genome of each strain presented unique sequences and only 50% of the predicted proteome was shared. To associate genomic features with metabolic capabilities of BCP1 and R7 strains, hundreds of different growth conditions were tested through Phenotype Microarray, by using Biolog plates and plates manually prepared with additional xenobiotic compounds. Around one-third of the surveyed carbon sources was utilized by both strains although R7 generally showed higher metabolic activity values compared to BCP1. Moreover, R7 showed broader range of nitrogen and sulphur sources. Phenotype Microarray data were combined with genomic analysis to genetically support the metabolic features of the two strains. The genome analysis allowed to identify some gene clusters involved in the metabolism of the main tested xenobiotic compounds. Results show that R7 contains multiple genes for the degradation of a large set of aromatic and PAHs compounds, while a lower variability in terms of genes predicted to be involved in aromatic degradation was found in BCP1. This genetic feature can be related to the strong genetic pressure exerted by the two different environment from which the two strains were isolated. According to this, in the BCP1 genome the smo gene cluster involved in the short-chain n-alkanes degradation, is included in one of the unique regions and it is not conserved in the Rhodococcus strains compared in this work. Data obtained underline the great potential of these two Rhodococcus spp. strains for biodegradation and environmental decontamination

  14. [Diagnosis and therapy of Rhodococcus equi infection in the horse].

    PubMed

    Boswinkel, M; Sloet van Oldruitenborgh-Oosterbaan, M M

    2006-09-01

    Infection with Rhodococcus equi is an important cause of pneumonia in foals, but other organ systems may also be affected. The intracellular presence of R. equi and the formation of granulomatous and suppurative inflammatory tissue mean that prolonged treatment is needed. The pharmacological properties of the combination of erythromycin and rifampicin have improved the survival of foals infected with R. equi; however, erythromycin can cause adverse reactions in foals and mares, which has prompted the search for alternative therapies. The combination of azithromycin or clarithromycin with rifampicin seems to be a promising alternative. However these combinations are expensive and adverse effects remain to be determined, especially in the dams of treated foals. Thus correct diagnosis and appropriate use of drugs are essential for the treatment of R. equi infection in foals. PMID:16989420

  15. An Adenoviral Vector Based Vaccine for Rhodococcus equi

    PubMed Central

    Giles, Carla; Ndi, Olasumbo; Barton, Mary D.; Vanniasinkam, Thiru

    2016-01-01

    Rhodococcus equi is a respiratory pathogen which primarily infects foals and is endemic on farms around the world with 50% mortality and 80% morbidity in affected foals. Unless detected early and treated appropriately the disease can be fatal. Currently, there is no vaccine available to prevent this disease. For decades researchers have endeavoured to develop an effective vaccine to no avail. In this study a novel human adenoviral vector vaccine for R. equi was developed and tested in the mouse model. This vaccine generated a strong antibody and cytokine response and clearance of R. equi was demonstrated following challenge. These results show that this vaccine could potentially be developed further for use as a vaccine to prevent R. equi disease in foals. PMID:27008624

  16. An Adenoviral Vector Based Vaccine for Rhodococcus equi.

    PubMed

    Giles, Carla; Ndi, Olasumbo; Barton, Mary D; Vanniasinkam, Thiru

    2016-01-01

    Rhodococcus equi is a respiratory pathogen which primarily infects foals and is endemic on farms around the world with 50% mortality and 80% morbidity in affected foals. Unless detected early and treated appropriately the disease can be fatal. Currently, there is no vaccine available to prevent this disease. For decades researchers have endeavoured to develop an effective vaccine to no avail. In this study a novel human adenoviral vector vaccine for R. equi was developed and tested in the mouse model. This vaccine generated a strong antibody and cytokine response and clearance of R. equi was demonstrated following challenge. These results show that this vaccine could potentially be developed further for use as a vaccine to prevent R. equi disease in foals. PMID:27008624

  17. Isopropanol and acetone induces vinyl chloride degradation in Rhodococcus rhodochrous.

    PubMed

    Kuntz, Robin L; Brown, Lewis R; Zappi, Mark E; French, W Todd

    2003-11-01

    In situ bioremediation of vinyl chloride (VC)-contaminated waste sites requires a microorganism capable of degrading VC. While propane will induce an oxygenase to accomplish this goal, its use as a primary substrate in bioremediation is complicated by its flammability and low water solubility. This study demonstrates that two degradation products of propane, isoproponal and acetone, can induce the enzymes in Rhodococcus rhodochrous that degrade VC. Additionally, a reasonable number of cells for bioremediation can be grown on conventional solid bacteriological media (nutrient agar, tryptic soy agar, plate count agar) in an average microbiological laboratory and then induced to produce the necessary enzymes by incubation of a resting cell suspension with isopropanol or acetone. Since acetone is more volatile than isopropanol and has other undesirable characteristics, isopropanol is the inducer of choice. It offers a non-toxic, water-soluble, relatively inexpensive alternative to propane for in situ bioremediation of waste sites contaminated with VC. PMID:14605909

  18. Initial Transformations in the Biodegradation of Benzothiazoles by Rhodococcus Isolates

    PubMed Central

    De Wever, Helene; Vereecken, Karen; Stolz, Andreas; Verachtert, Hubert

    1998-01-01

    Benzothiazole-2-sulfonate (BTSO3) is one of the side products occurring in 2-mercaptobenzothiazole (MBT) production wastewater. We are the first to isolate an axenic culture capable of BTSO3 degradation. The isolate was identified as a Rhodococcus erythropolis strain and also degraded 2-hydroxybenzothiazole (OBT) and benzothiazole (BT), but not MBT, which was found to inhibit the biodegradation of OBT, BT, and BTSO3. In anaerobic resting cell assays, BTSO3 was transformed into OBT in stoichiometric amounts. Under aerobic conditions, OBT was observed as an intermediate in BT breakdown and an unknown compound transiently accumulated in several assays. This product was identified as a dihydroxybenzothiazole. Benzothiazole degradation pathways seem to converge into OBT, which is then transformed further into the dihydroxy derivative. PMID:9726870

  19. Radiological findings in nine AIDS patients with Rhodococcus equi pneumonia.

    PubMed

    Wicky, S; Cartei, F; Mayor, B; Frija, J; Gevenois, P A; Giron, J; Laurent, F; Perri, G; Schnyder, P

    1996-01-01

    Rhodococcus equi (R. equi) infections have been incidentally reported as a cause of pulmonary infection in severely immunocompromised hosts, including AIDS patients. Our purpose is to describe the radiological findings in nine AIDS patients with R. equi pneumonia assessed by bronchoalveolar lavage (BAL), biopsies, cultures of sputum, and hemocultures. All patients were examined by chest radiographs and contrast-medium-enhanced chest CT. Dense pulmonary consolidations with or without cavitations accounted for the most striking radiological patterns. Chest CT also revealed six mediastinal involvements, strongly mimicking a lymphoma. Two of them had multiple bilateral pulmonary nodular opacities. Pleural effusion was not identified. Although intensive therapies were administered, seven among nine patients died within few months. In an AIDS patient living in a rural area or exposed to horses and presenting these radiological patterns, the possibility of R. equi pneumonia should be considered in the differential diagnosis along with other infectious diseases or lymphomas. PMID:8972317

  20. Investigation of the biotransformation of TNT by a Rhodococcus sp.

    SciTech Connect

    Tharakan, J.P.; Welsh, G.; Johnson, J.H. Jr.

    1995-12-31

    Tri-nitro-toluene (TNT) has contaminated waterways and soils as a result of its widespread military and non-military uses. Several researches have isolated or constructed strains of microorganisms that are able to utilize TNT as sole carbon, nitrogen or energy sources. Researchers have also reported high TNT concentrations (> 50 mg/l) as inhibitory to bacteria, yeast and fungi. This study examines the degradation of TNT and pyrene using a Rhodococcus sp. isolated based on its ability to survive on pyrene as the sole carbon source. The experiments were designed to study both the direct and cometabolic transformation of TNT by the microbes in both batch and continuous modes, and to determine the optimum conditions under which TNT would be degradable.

  1. A 2-Hydroxypyridine Catabolism Pathway in Rhodococcus rhodochrous Strain PY11

    PubMed Central

    Gasparavičiūtė, Renata; Rutkienė, Rasa; Tauraitė, Daiva; Meškys, Rolandas

    2015-01-01

    Rhodococcus rhodochrous PY11 (DSM 101666) is able to use 2-hydroxypyridine as a sole source of carbon and energy. By investigating a gene cluster (hpo) from this bacterium, we were able to reconstruct the catabolic pathway of 2-hydroxypyridine degradation. Here, we report that in Rhodococcus rhodochrous PY11, the initial hydroxylation of 2-hydroxypyridine is catalyzed by a four-component dioxygenase (HpoBCDF). A product of the dioxygenase reaction (3,6-dihydroxy-1,2,3,6-tetrahydropyridin-2-one) is further oxidized by HpoE to 2,3,6-trihydroxypyridine, which spontaneously forms a blue pigment. In addition, we show that the subsequent 2,3,6-trihydroxypyridine ring opening is catalyzed by the hypothetical cyclase HpoH. The final products of 2-hydroxypyridine degradation in Rhodococcus rhodochrous PY11 are ammonium ion and α-ketoglutarate. PMID:26655765

  2. Activity of 10 antimicrobial agents against intracellular Rhodococcus equi.

    PubMed

    Giguère, Steeve; Berghaus, Londa J; Lee, Elise A

    2015-08-01

    Studies with facultative intracellular bacterial pathogens have shown that evaluation of the bactericidal activity of antimicrobial agents against intracellular bacteria is more closely associated with in vivo efficacy than traditional in vitro susceptibility testing. The objective of this study was to determine the relative activity of 10 antimicrobial agents against intracellular Rhodococcus equi. Equine monocyte-derived macrophages were infected with virulent R. equi and exposed to erythromycin, clarithromycin, azithromycin, rifampin, ceftiofur, gentamicin, enrofloxacin, vancomycin, imipenem, or doxycycline at concentrations achievable in plasma at clinically recommended dosages in foals. The number of intracellular R. equi was determined 48h after infection by counting colony forming units (CFUs). The number of R. equi CFUs in untreated control wells were significantly higher than those of monolayers treated with antimicrobial agents. Numbers of R. equi were significantly lower in monolayers treated with enrofloxacin followed by those treated with gentamicin, and vancomycin, when compared to monolayers treated with other antimicrobial agents. Numbers of R. equi in monolayers treated with doxycycline were significantly higher than those of monolayers treated with other antimicrobial agents. Differences in R. equi CFUs between monolayers treated with other antimicrobial agents were not statistically significant. Enrofloxacin, gentamicin, and vancomycin are the most active drugs in equine monocyte-derived macrophages infected with R. equi. Additional studies will be needed to determine if these findings correlate with in vivo efficacy. PMID:26051479

  3. Blastogenic response of lymphocytes from foals infected with Rhodococcus equi.

    PubMed

    Sanada, Y; Noda, H; Nagahata, H

    1996-04-01

    The blastogenic response of lymphocytes from 16 newborn foals naturally infected with Rhodococcus equi was investigated, in order to evaluate the relationship between R. equi infection and depressed host response. Naturally infected foals showed evidence of R. equi infection at 5-6 weeks of age, as determined by clinical, haematological, bacteriological and serological methods. The blastogenic response of lymphocytes against phytohaemagglutinin was significantly depressed (stimulation index < 1.80; P < 0.01, P < 0.05) in R. equi-infected foals at 5-6 weeks of age compared with those of control foals. Serum IgG concentration decreased rapidly after foals reached 1 week of age, and minimum levels of IgG were observed at 5-7 weeks of age in R. equi-infected foals. This study suggests that the onset of R. equi infection may be associated with the depressed immune function of naturally infected foals during the first 5-6 weeks after birth. PMID:8693847

  4. [Antiadhesive potencial of Rhodococcus erythropolis IMB Ac-5017 biosurfactants].

    PubMed

    Pirog, T P; Gritsenko, N A; Konon, A D; Shevchuk, T A; Iutinskaia, G A

    2014-01-01

    The effect of Rhodococcus erythropolis IMB Ac-5017 biosurfactants (surface-active substances, SAS) with different degree of purification on attachment of bacteria (Escherichia coli IEM-1, Bacillus subtilis BT-2, Proteus vulgaris BT-1, Staphylococcus aureus BMC-1, Pseudomonas aeruginosa P-55, Enterobacter cloacae AC-22, Erwinia aroidaeae B-433), yeasts (Candida albicans D-6) and fungi (Aspergillus niger P-3, Fusarium culmorum T-7) to the abiotic surfaces (glass, plastic, ceramics, steel, linoleum) was studied. The dependence of microorganisms adhesion on degree of SAS purification (supernatant, purified SAS solution), SAS concentration (0,04-1,25 mg/ml), type of surface and test-cultures was established. The adhesion of majority investigated bacterial cells after treatment of abiotic surfaces with supernatant of cultural liquid with SAS concentration 0,06-0,25 mg/ml was on the average 20-45, yeasts C. albicans D-6--30-75% and was less than that purified SAS solution with the same concentration. Higher antiadhesive activity of supernatant as compared to purified SAS solution testifies to possibility of exception of the expensive stage of isolation and purification at obtaining of preparations with antiadhesive properties. PMID:25639039

  5. Comparative and Functional Genomics of Rhodococcus opacus PD630 for Biofuels Development

    PubMed Central

    Holder, Jason W.; Ulrich, Jil C.; DeBono, Anthony C.; Godfrey, Paul A.; Desjardins, Christopher A.; Zucker, Jeremy; Zeng, Qiandong; Leach, Alex L. B.; Ghiviriga, Ion; Dancel, Christine; Abeel, Thomas; Gevers, Dirk; Kodira, Chinnappa D.; Desany, Brian; Affourtit, Jason P.; Birren, Bruce W.; Sinskey, Anthony J.

    2011-01-01

    The Actinomycetales bacteria Rhodococcus opacus PD630 and Rhodococcus jostii RHA1 bioconvert a diverse range of organic substrates through lipid biosynthesis into large quantities of energy-rich triacylglycerols (TAGs). To describe the genetic basis of the Rhodococcus oleaginous metabolism, we sequenced and performed comparative analysis of the 9.27 Mb R. opacus PD630 genome. Metabolic-reconstruction assigned 2017 enzymatic reactions to the 8632 R. opacus PD630 genes we identified. Of these, 261 genes were implicated in the R. opacus PD630 TAGs cycle by metabolic reconstruction and gene family analysis. Rhodococcus synthesizes uncommon straight-chain odd-carbon fatty acids in high abundance and stores them as TAGs. We have identified these to be pentadecanoic, heptadecanoic, and cis-heptadecenoic acids. To identify bioconversion pathways, we screened R. opacus PD630, R. jostii RHA1, Ralstonia eutropha H16, and C. glutamicum 13032 for growth on 190 compounds. The results of the catabolic screen, phylogenetic analysis of the TAGs cycle enzymes, and metabolic product characterizations were integrated into a working model of prokaryotic oleaginy. PMID:21931557

  6. Comparison of Etest, disk diffusion, and broth macrodilution for in vitro susceptibility testing of Rhodococcus equi.

    PubMed

    Berghaus, Londa J; Giguère, Steeve; Guldbech, Kristen; Warner, Eleanor; Ugorji, Ukachi; Berghaus, Roy D

    2015-01-01

    MICs of erythromycin, clarithromycin, azithromycin, rifampin, gentamicin, and doxycycline against 101 isolates of Rhodococcus equi were determined by broth macrodilution, disk diffusion, and Etest. Categorical agreement ranged between 85.1 and 100%. Overall, the agreement between Etest and disk diffusion was better than the agreement between broth macrodilution and the agar-based methods. PMID:25378571

  7. Comparison of Etest, Disk Diffusion, and Broth Macrodilution for In Vitro Susceptibility Testing of Rhodococcus equi

    PubMed Central

    Berghaus, Londa J.; Guldbech, Kristen; Warner, Eleanor; Ugorji, Ukachi; Berghaus, Roy D.

    2014-01-01

    MICs of erythromycin, clarithromycin, azithromycin, rifampin, gentamicin, and doxycycline against 101 isolates of Rhodococcus equi were determined by broth macrodilution, disk diffusion, and Etest. Categorical agreement ranged between 85.1 and 100%. Overall, the agreement between Etest and disk diffusion was better than the agreement between broth macrodilution and the agar-based methods. PMID:25378571

  8. First Report of Sepsis Caused by Rhodococcus corynebacterioides in a Patient with Myelodysplastic Syndrome

    PubMed Central

    Kitamura, Yuka; Sawabe, Etsuko; Ohkusu, Kiyofumi; Tojo, Naoko

    2012-01-01

    We report a case of sepsis caused by Rhodococcus corynebacterioides, identified using 16S rRNA gene sequencing, in a myelodysplastic syndrome patient who had undergone hematopoietic stem cell transplantation. This is the first report of R. corynebacterioides infection in a human. PMID:22205796

  9. Genome Sequence of Rhodococcus opacus Strain R7, a Biodegrader of Mono- and Polycyclic Aromatic Hydrocarbons

    PubMed Central

    Zampolli, J.; Presti, I.; Cappelletti, M.; D’Ursi, P.; Orro, A.; Mezzelani, A.; Milanesi, L.

    2014-01-01

    Rhodococcus opacus strain R7 (CIP107348) degrades several mono- and polycyclic aromatic hydrocarbons. Here, we present the high-quality draft genome sequence of strain R7, consisting of 10,118,052 bp, with a G+C content of 67.0%, 9,602 protein-coding genes, and 62 RNAs genes. PMID:25146139

  10. Deep Desulfurization of Extensively Hydrodesulfurized Middle Distillate Oil by Rhodococcus sp. Strain ECRD-1

    PubMed Central

    Grossman, M. J.; Lee, M. K.; Prince, R. C.; Minak-Bernero, V.; George, G. N.; Pickering, I. J.

    2001-01-01

    Dibenzothiophene (DBT), and in particular substituted DBTs, are resistant to hydrodesulfurization (HDS) and can persist in fuels even after aggressive HDS treatment. Treatment by Rhodococcus sp. strain ECRD-1 of a middle distillate oil whose sulfur content was virtually all substituted DBTs produced extensive desulfurization and a sulfur level of 56 ppm. PMID:11282654

  11. Rhodococcus equi hyperimmune plasma decreases pneumonia severity after a randomised experimental challenge of neonatal foals.

    PubMed

    Sanz, M G; Loynachan, A; Horohov, D W

    2016-03-12

    Since a vaccine is not available against Rhodococcus equi, R equi-specific hyperimmune plasma (HIP) is commonly used, although its efficacy remains controversial. The objective of this study was to evaluate the ability of a commercially available HIP to prevent clinical rhodococcal pneumonia in neonatal foals after experimental challenge. PMID:26932206

  12. Conversion of the Pseudomonas aeruginosa Quinolone Signal and Related Alkylhydroxyquinolines by Rhodococcus sp. Strain BG43

    PubMed Central

    Müller, Christine; Birmes, Franziska S.; Niewerth, Heiko

    2014-01-01

    A bacterial strain, which based on the sequences of its 16S rRNA, gyrB, catA, and qsdA genes, was identified as a Rhodococcus sp. closely related to Rhodococcus erythropolis, was isolated from soil by enrichment on the Pseudomonas quinolone signal [PQS; 2-heptyl-3-hydroxy-4(1H)-quinolone], a quorum sensing signal employed by the opportunistic pathogen Pseudomonas aeruginosa. The isolate, termed Rhodococcus sp. strain BG43, cometabolically degraded PQS and its biosynthetic precursor 2-heptyl-4(1H)-quinolone (HHQ) to anthranilic acid. HHQ degradation was accompanied by transient formation of PQS, and HHQ hydroxylation by cell extracts required NADH, indicating that strain BG43 has a HHQ monooxygenase isofunctional to the biosynthetic enzyme PqsH of P. aeruginosa. The enzymes catalyzing HHQ hydroxylation and PQS degradation were inducible by PQS, suggesting a specific pathway. Remarkably, Rhodococcus sp. BG43 is also capable of transforming 2-heptyl-4-hydroxyquinoline-N-oxide to PQS. It thus converts an antibacterial secondary metabolite of P. aeruginosa to a quorum sensing signal molecule. PMID:25239889

  13. Pyogenic Liver Abscess Due to Rhodococcus equi in an Immunocompetent Host

    PubMed Central

    Napoleão, Fátima; Vieira Damasco, Paulo; Ferreira Camello, Thereza Cristina; Damasceno do Vale, Márcio; Braga de Andrade, Arnaldo Feitosa; Hirata, Raphael; de Mattos-Guaraldi, Ana Luíza

    2005-01-01

    A case of pyogenic liver abscess (PLA) due to Rhodococcus equi in an immunocompetent individual was successfully treated by combining surgery and antibiotics. The R. equi-targeted antimicrobial agents erythromycin and rifampin were used only after surgical resection of the lesion and identification of the infective organism. PMID:15695730

  14. Deep desulfurization of extensively hydrodesulfurized middle distillate oil by Rhodococcus sp. strain ECRD-1.

    PubMed

    Grossman, M J; Lee, M K; Prince, R C; Minak-Bernero, V; George, G N; Pickering, I J

    2001-04-01

    Dibenzothiophene (DBT), and in particular substituted DBTs, are resistant to hydrodesulfurization (HDS) and can persist in fuels even after aggressive HDS treatment. Treatment by Rhodococcus sp. strain ECRD-1 of a middle distillate oil whose sulfur content was virtually all substituted DBTs produced extensive desulfurization and a sulfur level of 56 ppm. PMID:11282654

  15. Comparison of three techniques for isolation of Rhodococcus (Corynebacterium) equi from contaminated sources.

    PubMed

    Barton, M D; Hughes, K L

    1981-01-01

    Inoculation of a liquid medium comprised of Trypticase soy broth (BBL Microbiology Systems), cycloheximide, nalidixic acid, penicillin, and potassium tellurite and subcultured onto M3 medium plus potassium tellurite was highly successful for the isolation of Rhodococcus (Corynebacterium) equi from soil. PMID:7007424

  16. Analysis of genome sequences from plant pathogenic Rhodococcus reveals genetic novelties in virulence loci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Members of Gram-positive Actinobacteria cause economically important diseases to plants. Within the Rhodococcus genus, some members can cause growth deformities and persist as pathogens on a wide range of host plants. The current model predicts that phytopathogenic isolates require a cluster of thre...

  17. Establishment of Cellobiose Utilization for Lipid Production in Rhodococcus opacus PD630

    PubMed Central

    Hetzler, Stephan

    2013-01-01

    Rhodococcus opacus PD630, which is known for its ability to accumulate large amounts of triacylglycerols (TAG), was metabolically engineered, and a cellobiose utilization pathway was introduced. Activities of β-glucosidases were determined, and recombinant strains accumulated fatty acids up to 39.5 ± 5.7% (wt/wt) of cell dry mass from cellobiose. PMID:23435878

  18. Draft Genome Sequence of an Aldoxime Degrader, Rhodococcus sp. Strain YH3-3

    PubMed Central

    2016-01-01

    Rhodococcus sp. strain YH3-3 has been isolated as an (E)-pyridine-3-aldoxime degrader. Here, we report the draft genome sequence of this strain, with a size of 7,316,908 bp, average G+C content of 62.15%, and 7,281 predicted protein-coding sequences. PMID:27198031

  19. Analysis of Genome Sequences from Plant Pathogenic Rhodococcus Reveals Genetic Novelties in Virulence Loci

    PubMed Central

    Davis, Edward W.; Putnam, Melodie L.; Hu, Erdong; Swader-Hines, David; Mol, Adeline; Baucher, Marie; Prinsen, Els; Zdanowska, Magdalena; Givan, Scott A.; Jaziri, Mondher El; Loper, Joyce E.; Mahmud, Taifo; Chang, Jeff H.

    2014-01-01

    Members of Gram-positive Actinobacteria cause economically important diseases to plants. Within the Rhodococcus genus, some members can cause growth deformities and persist as pathogens on a wide range of host plants. The current model predicts that phytopathogenic isolates require a cluster of three loci present on a linear plasmid, with the fas operon central to virulence. The Fas proteins synthesize, modify, and activate a mixture of growth regulating cytokinins, which cause a hormonal imbalance in plants, resulting in abnormal growth. We sequenced and compared the genomes of 20 isolates of Rhodococcus to gain insights into the mechanisms and evolution of virulence in these bacteria. Horizontal gene transfer was identified as critical but limited in the scale of virulence evolution, as few loci are conserved and exclusive to phytopathogenic isolates. Although the fas operon is present in most phytopathogenic isolates, it is absent from phytopathogenic isolate A21d2. Instead, this isolate has a horizontally acquired gene chimera that encodes a novel fusion protein with isopentyltransferase and phosphoribohydrolase domains, predicted to be capable of catalyzing and activating cytokinins, respectively. Cytokinin profiling of the archetypal D188 isolate revealed only one activate cytokinin type that was specifically synthesized in a fas-dependent manner. These results suggest that only the isopentenyladenine cytokinin type is synthesized and necessary for Rhodococcus phytopathogenicity, which is not consistent with the extant model stating that a mixture of cytokinins is necessary for Rhodococcus to cause leafy gall symptoms. In all, data indicate that only four horizontally acquired functions are sufficient to confer the trait of phytopathogenicity to members of the genetically diverse clade of Rhodococcus. PMID:25010934

  20. Isolation and characterization of RDX-degrading Rhodococcus species from a contaminated aquifer.

    PubMed

    Bernstein, Anat; Adar, Eilon; Nejidat, Ali; Ronen, Zeev

    2011-09-01

    Groundwater contamination by the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a global problem. Israel's coastal aquifer was contaminated with RDX. This aquifer is mostly aerobic and we therefore sought aerobic bacteria that might be involved in natural attenuation of the compound in the aquifer. RDX-degrading bacteria were captured by passively sampling the indigenous bacteria onto sterile sediments placed within sampling boreholes. Aerobic RDX biodegradation potential was detected in the sediments sampled from different locations along the plume. RDX degradation with the native sampled consortium was accompanied by 4-nitro-2,4-diazabutanal formation. Two bacterial strains of the genus Rhodococcus were isolated from the sediments and identified as aerobic RDX degraders. The xplA gene encoding the cytochrome P450 enzyme was partially (~500 bp) sequenced from both isolates. The obtained DNA sequences had 99% identity with corresponding gene fragments of previously isolated RDX-degrading Rhodococcus strains. RDX degradation by both strains was prevented by 200 μM of the cytochrome P450 inhibitor metyrapone, suggesting that cytochrome P450 indeed mediates the initial step in RDX degradation. RDX biodegradation activity by the T7 isolate was inhibited in the presence of nitrate or ammonium concentrations above 1.6 and 5.5 mM, respectively (100 mg l(-1)) while the T9N isolate's activity was retarded only by ammonium concentrations above 5.5 mM. This study shows that bacteria from the genus Rhodococcus, potentially degrade RDX in the saturated zone as well, following the same aerobic degradation pathway defined for other Rhodococcus species. RDX-degrading activity by the Rhodococcus species isolate T9N may have important implications for the bioremediation of nitrate-rich RDX-contaminated aquifers. PMID:21327803

  1. Metabolism of carveol and dihydrocarveol in Rhodococcus erythropolis DCL14.

    PubMed

    van der Werf, M J; Boot, A M

    2000-05-01

    Rhodococcus erythropolis DCL14 assimilates all stereoisomers of carveol and dihydrocarveol as sole source of carbon and energy. Induction experiments with carveol- or dihydrocarveol-grown cells showed high oxygen consumption rates with these two compounds and with carvone and dihydrocarvone. (Dihydro)carveol-grown cells of R. erythropolis DCL14 contained the following enzymic activities involved in the carveol and dihydrocarveol degradation pathways of this micro-organism: (dihydro)carveol dehydrogenase (both NAD+- and dichlorophenolindophenol-dependent activities), an unknown cofactor-dependent carvone reductase, (iso-)dihydrocarvone isomerase activity, NADPH-dependent dihydrocarvone monooxygenase (Baeyer-Villiger monooxygenase), epsilon-lactone hydrolase and an NAD+-dependent 6-hydroxy-3-isopropenylheptanoate dehydrogenase. Product accumulation studies identified (4R)-carvone, (1R,4R)-dihydrocarvone, (4R,7R)-4-isopropenyl-7-methyl-2-oxo-oxepanone, (3R)-6-hydroxy-3-isopropenylheptanoate, (3R)-3-isopropenyl-6-oxoheptanoate, (3S,6R)-6-isopropenyl-3-methyl-2-oxooxepanone and (5R)-6-hydroxy-5-isopropenyl-2-methylhexanoate as intermediates in the (4R)-carveol degradation pathway. The opposite stereoisomers of these compounds were identified in the (4S)-carveol degradation pathway. With dihydrocarveol, the same intermediates are involved except that carvone was absent. These results show that R. erythropolis DCL14 metabolizes all four diastereomers of carveol via oxidation to carvone, which is subsequently stereospecifically reduced to (1R)-(iso-) dihydrocarvone. At this point also dihydrocarveol enters the pathway, and this compound is directly oxidized to (iso-)dihydrocarvone. Cell extracts contained both (1R)-(iso-)dihydrocarvone 1,2-monooxygenase and (1S)-(iso)-dihydrocarvone 2,3-monooxygenase activity, resulting in a branch point of the degradation pathway; (1R)-(iso-)dihydrocarvone was converted to 4-isopropenyl-7-methyl-2-oxo-oxepanone, while (1S

  2. Conservation of Rhodococcus equi (Magnusson 1923) Goodfellow and Alderson 1977 and rejection of Corynebacterium hoagii (Morse 1912) Eberson 1918.

    PubMed

    Garrity, George M

    2014-01-01

    A recent review of the nomenclatural history of Rhodococcus equi and its heterotypic synonyms reveals a situation in which the strict application of the Rules of the International Code of Nomenclature of Prokaryotes have resulted in the renaming of this known zoonotic pathogen, which may be reasonably viewed as a perilous name. This situation can be remedied only by the Judicial Commission rendering an opinion to conserve the name Rhodococcus equi and to reject its earlier heterotypic synonym, Corynebacterium hoagii. PMID:24408953

  3. [Cloning of new acylamidase gene from Rhodococcus erythropolis and its expression in Escherichia coli].

    PubMed

    Lavrov, K V; Ianenko, A S

    2013-10-01

    The gene for new Rhodococcus erythropolis TA37 acylamidase, which possesses unique substrate specificity, has been cloned and expressed in E. coli. Substrates for this enzyme are not only simple amides, such as acetamide and propionamide, but also N-substituted amides, such as 4'-nitroacetanilide. The 1431-bp gene was expressed in E. coli BL21 (DE3) cells on pET16b plasmid under the control of a promoter of the φ 10 gene from the T7 phage. The molecular mass of recombinant acylamidase in E. coli was 55 kDa, which corresponded to that of native acylamidase from Rhodococcus erythropolis TA37. Recombinant acylamidase was able to hydrolize N-substituted amides. A search of a nucleotide database and multiple alignment revealed that acylamidase belonged to the Amidase protein family PF01425, but its nucleotide and amino acid sequences differed significantly from those of the described amidases. PMID:25474901

  4. [Cloning of new acylamidase gene from Rhodococcus erythropolis and its expression in Escherichia coli].

    PubMed

    2013-10-01

    The gene for new Rhodococcus erythropolis TA37 acylamidase, which possesses unique substrate specificity, has been cloned and expressed in E. coli. Substrates for this enzyme are not only simple amides, such as acetamide and propionamide, but also N-substituted amides, such as 4'-nitroacetanilide. The 1431-bp gene was expressed in E. coli BL21 (DE3) cells on pET16b plasmid under the control of a promoter of the φ 10 gene from the T7 phage. The molecular mass of recombinant acylamidase in E. coli was 55 kDa, which corresponded to that of native acylamidase from Rhodococcus erythropolis TA37. Recombinant acylamidase was able to hydrolize N-substituted amides. A search of a nucleotide database and multiple alignment revealed that acylamidase belonged to the Amidase protein family PF01425, but its nucleotide and amino acid sequences differed significantly from those of the described amidases. PMID:25508680

  5. Activity of Clarithromycin or Rifampin Alone or in Combination against Experimental Rhodococcus equi Infection in Mice

    PubMed Central

    Burton, Alexandra J.; Berghaus, Londa J.; Hondalus, Mary K.

    2015-01-01

    Treatment of mice with the combination of clarithromycin with rifampin resulted in a significantly lower number of Rhodococcus equi CFU in the organs of mice than treatment with either drug alone or placebo. There was no significant difference in the number of R. equi CFU between mice treated with clarithromycin monotherapy, rifampin monotherapy, or placebo. The combination of clarithromycin with rifampin conferred a clear advantage over either drug as monotherapy in this model of chronic R. equi infection. PMID:25824218

  6. Rhodococcus jostii porin A (RjpA) functions in cholate uptake.

    PubMed

    Somalinga, Vijayakumar; Mohn, William W

    2013-10-01

    RjpA in Rhodococcus jostii is the ortholog of a channel-forming porin, MspA. Deletion of rjpA delayed growth of R. jostii on cholate but not on cholesterol. Eventual growth on cholate involved increased expression of other porins, namely, RjpB, RjpC, and RjpD. Porins appear essential for the uptake of bile acids by mycolic acid bacteria. PMID:23892747

  7. Thiocarbamate herbicide-inducible nonheme haloperoxidase of Rhodococcus erythropolis NI86/21.

    PubMed Central

    De Schrijver, A; Nagy, I; Schoofs, G; Proost, P; Vanderleyden, J; van Pée, K H; De Mot, R

    1997-01-01

    During biodegradation of thiocarbamate herbicides by Rhodococcus erythropolis NI86/21, a protein with an M(r) of 30,000 is induced (I. Nagy, G. Schoofs, F. Compernolle, P. Proost, J. Vanderleyden, and R.De Mot, J. Bacteriol. 177:676-687, 1995). Based on N-terminal sequence data for the protein purified by two-dimensional electrophoresis, the corresponding structural gene, thcF, was cloned and sequenced. The deduced protein sequence of ThcF is homologous to those of nonheme haloperoxidases. A particularly high level of sequence identity (72.6%) was observed for the chloroperoxidase from Pseudomonas pyrrocinia. A polyclonal antibody against the latter enzyme cross-reacted with ThcF either produced by the original Rhodococcus cells or overexpressed heterologously in Escherichia coli. In both thiocarbamate-grown Rhodococcus cells and E. coli cells expressing thcF, the haloperoxidase activity of ThcF was demonstrated. The thiocarbamate-inducible R. erythropolis ThcF protein represents the first (nonheme) haloperoxidase to be identified in a nocardioform actinomycete. PMID:9143122

  8. Membrane transport systems and the biodegradation potential and pathogenicity of genus Rhodococcus

    PubMed Central

    de Carvalho, Carla C. C. R.; Costa, Sofia S.; Fernandes, Pedro; Couto, Isabel; Viveiros, Miguel

    2014-01-01

    The Rhodococcus genus contains species with remarkable ability to tolerate toxic compounds and to degrade a myriad of substrates. These substrates have to cross a distinctive cell envelope dominated by mycolic acids anchored in a scaffold of arabinogalactan covalently attached to the cell wall peptidoglycan, and a cellular membrane with phospholipids, whose composition in fatty acids can be rapidly altered in response to environmental conditions. The hydrophobic nature of the cell envelope facilitates the entrance of hydrophobic molecules but some substrates require active transport systems. Additionally, toxic compounds may also be extruded by energy spending efflux systems. In this review, physiological evidences of the use of transport systems by Rhodococcus strains and genomic studies that corroborate their existence are presented and discussed. The recently released complete genomes of several Rhodococcus strains will be the basis for an in silico correlation analysis between the efflux pumps present in the genome and their role on active transport of substrates. These transport systems will be placed on an integrative perspective of the impact of this important genus on biotechnology and health, ranging from bioremediation to antibiotic and biocide resistance. PMID:24772091

  9. Analysis of Genes for Succinoyl Trehalose Lipid Production and Increasing Production in Rhodococcus sp. Strain SD-74

    PubMed Central

    Inaba, Tomohiro; Tokumoto, Yuta; Miyazaki, Yusuke; Inoue, Naoyuki; Maseda, Hideaki; Nakajima-Kambe, Toshiaki; Uchiyama, Hiroo

    2013-01-01

    Succinoyl trehalose lipids (STLs) are promising glycolipid biosurfactants produced from n-alkanes that are secreted by Rhodococcus species bacteria. These compounds not only exhibit unique interfacial properties but also demonstrate versatile biochemical actions. In this study, three novel types of genes involved in the biosynthesis of STLs, including a putative acyl coenzyme A (acyl-CoA) transferase (tlsA), fructose-bisphosphate aldolase (fda), and alkane monooxygenase (alkB), were identified. The predicted functions of these genes indicate that alkane metabolism, sugar synthesis, and the addition of acyl groups are important for the biosynthesis of STLs. Based on these results, we propose a biosynthesis pathway for STLs from alkanes in Rhodococcus sp. strain SD-74. By overexpressing tlsA, we achieved a 2-fold increase in the production of STLs. This study advances our understanding of bacterial glycolipid production in Rhodococcus species. PMID:24038682

  10. 3-nitroadipate, a metabolic intermediate for mineralization of 2, 4-dinitrophenol by a new strain of a Rhodococcus species.

    PubMed

    Blasco, R; Moore, E; Wray, V; Pieper, D; Timmis, K; Castillo, F

    1999-01-01

    The bacterial strain RB1 has been isolated by enrichment cultivation with 2,4-dinitrophenol as the sole nitrogen, carbon, and energy source and characterized, on the basis of 16S rRNA gene sequence comparison, as a Rhodococcus species closely related to Rhodococcus opacus. Rhodococcus sp. strain RB1 degrades 2,4-dinitrophenol, releasing the two nitro groups from the compound as nitrite. The release of nitro groups from 2,4-dinitrophenol occurs in two steps. First, the 2-nitro group is removed as nitrite, with the production of an aliphatic nitro compound identified by 1H nuclear magnetic resonance and mass spectrometry as 3-nitroadipate. Then, this metabolic derivative is further metabolized, releasing its nitro group as nitrite. Full nitrite assimilation upon reduction to ammonia requires that an additional carbon source be supplied to the medium. PMID:9864324

  11. Cometabolic Degradation of Trichloroethene by Rhodococcus sp. Strain L4 Immobilized on Plant Materials Rich in Essential Oils▿ †

    PubMed Central

    Suttinun, Oramas; Müller, Rudolf; Luepromchai, Ekawan

    2010-01-01

    The cometabolic degradation of trichloroethene (TCE) by Rhodococcus sp. L4 was limited by the loss of enzyme activity during TCE transformation. This problem was overcome by repeated addition of inducing substrates, such as cumene, limonene, or cumin aldehyde, to the cells. Alternatively, Rhodococcus sp. L4 was immobilized on plant materials which contain those inducers in their essential oils. Cumin seeds were the most suitable immobilizing material, and the immobilized cells tolerated up to 68 μM TCE and degraded TCE continuously. The activity of immobilized cells, which had been inactivated partially during TCE degradation, could be reactivated by incubation in mineral salts medium without TCE. These findings demonstrate that immobilization of Rhodococcus sp. L4 on plant materials rich in essential oils is a promising method for efficient cometabolic degradation of TCE. PMID:20472723

  12. Rhodococcus opacus B4: a promising bacterium for production of biofuels and biobased chemicals.

    PubMed

    Castro, Ana Rita; Rocha, Isabel; Alves, Maria Madalena; Pereira, Maria Alcina

    2016-12-01

    Bacterial lipids have relevant applications in the production of renewable fuels and biobased oleochemicals. The genus Rhodococcus is one of the most relevant lipid producers due to its capability to accumulate those compounds, mainly triacylglycerols (TAG), when cultivated on different defined substrates, namely sugars, organic acids and hydrocarbons but also on complex carbon sources present in industrial wastes. In this work, the production of storage lipids by Rhodococcus opacus B4 using glucose, acetate and hexadecane is reported for the first time and its productivity compared with Rhodococcus opacus PD630, the best TAG producer bacterium reported. Both strains accumulated mainly TAG from all carbon sources, being influenced by the carbon source itself and by the duration of the accumulation period. R. opacus B4 produced 0.09 and 0.14 g L(-1) at 24 and 72 h, with hexadecane as carbon source, which was 2 and 3.3 fold higher than the volumetric production obtained by R. opacus PD630. Both strains presented similar fatty acids (FA) profiles in intact cells while in TAG produced fraction, R. opacus B4 revealed a higher variability in fatty acid composition than R. opacus PD630, when both strains were cultivated on hexadecane. The obtained results open new perspectives for the use of R. opacus B4 to produce TAG, in particular using oily (alkane-contaminated) waste and wastewater as cheap raw-materials. Combining TAG production with hydrocarbons degradation is a promising strategy to achieve environmental remediation while producing added value compounds. PMID:27179529

  13. Biodegradation of variable-chain-length alkanes at low temperatures by a psychrotrophic Rhodococcus sp.

    SciTech Connect

    Whyte, L.G.; Hawari, J.; Zhou, E.; Bourbonniere, L.; Greer, C.W.; Inniss, W.E.

    1998-07-01

    The psychrotroph Rhodococcus sp. strain Q15 was examined for its ability to degrade individual n-alkanes and diesel fuel at low temperatures, and its alkane catabolic pathway was investigated by biochemical and genetic techniques. At 0 and 5 C, Q15 mineralized the short-chain alkanes dodecane and hexadecane to a greater extent than that observed for the long-chain alkanes octacosane and dotriacontane. Q15 utilized a broad range of aliphatics (C{sub 10} to C{sub 21} alkanes, branched alkanes, and a substituted cyclohexane) present in diesel fuel at 5 C. Mineralization of hexadecane at 5 C was significantly greater in both hydrocarbon-contaminated and pristine soil microcosms seeded with Q15 cells than in uninoculated control soil microcosms. The detection of hexadecane and dodecane metabolic intermediates (1-hexadecanol and 2-hexadecanol and 1-do-decanol and 2-dodecanone, respectively) by solid-phase microextraction-gas chromatography-mass spectrometry and the utilization of potential metabolic intermediates indicated that Q15 oxidizes alkanes by both the terminal oxidation pathway and the subterminal oxidation pathway. Genetic characterization by PCR and nucleotide sequence analysis indicated that Q15 possesses an aliphatic aldehyde dehydrogenase gene highly homologous to the Rhodococcus erythropolis thcA gene. Rhodococcus sp. strain Q15 possessed two large plasmids of approximately 90 and 115 kb (shown to mediate Cd resistance) which were not required for alkane mineralization, although the 90-kb plasmid enhanced mineralization of some alkanes and growth on diesel oil at both 5 and 25 C.

  14. Non-pulmonary Rhodococcus equi infections in patients with acquired immune deficiency syndrome (AIDS).

    PubMed Central

    Fierer, J; Wolf, P; Seed, L; Gay, T; Noonan, K; Haghighi, P

    1987-01-01

    Rhodococcus equi, formerly known as Corynebacterium equi, was isolated repeatedly from the blood of two patients with the acquired immune deficiency syndrome (AIDS). Neither of the patients had pneumonia while they were bacteraemic, whereas pneumonia has been present in all previously reported cases of human infection with R equi. One of our patients had diarrhoea and the organism was isolated from a stool culture; the other patient had a large granulomatous soft tissue mass in his pelvis caused by R equi. Both isolates were resistant to penicillin and one produced a beta-lactamase. Both patients were treated with vancomycin but only one recovered. Images Figure PMID:3584508

  15. Initial hydrogenation during catabolism of picric acid by Rhodococcus erythropolis HL 24-2.

    PubMed Central

    Lenke, H; Knackmuss, H J

    1992-01-01

    Rhodococcus erythropolis HL 24-2, which was originally isolated as a 2,4-dinitrophenol-degrading bacterium, could also utilize picric acid as a nitrogen source after spontaneous mutation. During growth, the mutant HL PM-1 transiently accumulated an orange-red metabolite, which was identified as a hydride-Meisenheimer complex of picric acid. This complex was formed as the initial metabolite and further converted with concomitant liberation of nitrite. 2,4,6-Trinitrocyclohexanone was identified as a dead-end metabolite of the degradation of picric acid, indicating the addition of two hydride ions to picric acid. PMID:1444408

  16. Cavitary pneumonia due to Rhodococcus equi in a heart transplant recipient.

    PubMed

    Kwak, E J; Strollo, D C; Kulich, S M; Kusne, S

    2003-03-01

    Rhodococcus equi is an uncommon human pathogen that usually affects immunocompromised patients. We present a case of a 68-year-old male heart transplant recipient, who developed rhodococcal pneumonia with secondary bacteremia 10 months post-transplant. The patient was a retired carpenter who was involved in breeding of horses. He responded completely to the treatment with vancomycin and imipenem/cilastin, followed by oral ciprofloxacin and minocycline for total treatment duration of 5 months. This case highlights the association between an animal exposure and infection with a unique opportunistic pathogen. PMID:12791074

  17. Diagnosis, treatment, control, and prevention of infections caused by Rhodococcus equi in foals.

    PubMed

    Giguère, S; Cohen, N D; Chaffin, M Keith; Slovis, N M; Hondalus, M K; Hines, S A; Prescott, J F

    2011-01-01

    Rhodococcus equi, a gram-positive facultative intracellular pathogen, is one of the most common causes of pneumonia in foals. Although R. equi can be cultured from the environment of virtually all horse farms, the clinical disease in foals is endemic at some farms, sporadic at others, and unrecognized at many. On farms where the disease is endemic, costs associated with morbidity and mortality attributable to R. equi may be very high. The purpose of this consensus statement is to provide recommendations regarding the diagnosis, treatment, control, and prevention of infections caused by R. equi in foals. PMID:22092608

  18. Failure of hyperimmune plasma to prevent pneumonia caused by Rhodococcus equi in foals.

    PubMed

    Hurley, J R; Begg, A P

    1995-11-01

    A trial was conducted on a Thoroughbred stud to determine whether or not the administration of anti-Rhodococcus equi hyperimmune plasma would reduce the prevalence of R equi pneumonia (rattles) in foals born in the 1992 horse breeding season. Hyperimmune plasma was administered to 34 foals; another 57 foals were untreated. There was no significant difference in the number of transfused foals developing R equi pneumonia compared with the untreated foals. The time required for recovery from pneumonia between the 2 groups was not significantly different. PMID:8929188

  19. Hydrophobised sawdust as a carrier for immobilisation of the hydrocarbon-oxidizing bacterium Rhodococcus ruber.

    PubMed

    Podorozhko, Elena A; Lozinsky, Vladimir I; Ivshina, Irena B; Kuyukina, Maria S; Krivorutchko, Anastasiya B; Philp, Jim C; Cunningham, Colin J

    2008-04-01

    Pine sawdust treated by a series of hydrophobising agents (drying oil, organosilicon emulsion, n-hexadecane and paraffin) was examined as carrier for adsorption immobilisation of hydrocarbon-oxidizing bacterial cells Rhodococcus ruber. It was shown that hydrophobising agents based on drying oil turned out to be optimal (among the other modifiers examined) for the preparation of sawdust carriers suitable for the efficient immobilisation. The results obtained demonstrate promising possibilities in developing a wide range of available and cheap, biodegradable cellulose-containing carriers that possess varying surface hydrophobicity. PMID:17481891

  20. Cyanobactericidal effect of Rhodococcus sp. isolated from eutrophic lake on Microcystis sp.

    PubMed

    Lee, Young-Ki; Ahn, Chi-Yong; Kim, Hee-Sik; Oh, Hee-Mock

    2010-11-01

    A bacterium, which was observed in all cultivations of Microcystis sp., was isolated and designated as Rhodococcus sp. KWR2. The growth of bloom-forming cyanobacteria, including four strains of Microcystis aeruginosa and Anabaena variabilis, was suppressed by up to 75-88% by 2% (v/v) culture broth of KWR2 after 5 days. But KWR2 did not inhibit eukaryotic algae, Chlorella vulgaris and Scenedesmus sp. An extracellular algicidal substance produced by KWR2 showed a cyanobactericidal activity of 94% and was water-soluble with a molecular weight of lower than 8 kDa. PMID:20640876

  1. Rhodococcus equi Sepsis in a Renal Transplant Recipient: A Case Study

    PubMed Central

    Macken, Eline; de Jonge, Hylke; Van Caesbroeck, Daniël; Verhaegen, Jan; Van Kerkhoven, Dana; Van Wijngaerden, Eric; Kuypers, Dirk

    2015-01-01

    Abstract Rhodococcus equi is an unusual cause of infection in humans, but has emerged as an opportunistic pathogen among immunocompromised patients. Primary pulmonary involvement is the most common clinical presentation, although the spectrum of disease is broad. Diagnosing R. equi infections remains challenging, both from clinical and microbiological view, and no standard treatment has been established. In this report, we present a detailed case of a 57-year-old male renal transplant recipient who developed R. equi bacteremia with a concomitant Pneumocystis jirovecii pneumonia. We describe the clinical features of R. equi infections, highlight the importance of an early diagnosis, and briefly review treatment options for this rare infection. PMID:27500216

  2. A Leaf-Inhabiting Endophytic Bacterium, Rhodococcus sp. KB6, Enhances Sweet Potato Resistance to Black Rot Disease Caused by Ceratocystis fimbriata.

    PubMed

    Hong, Chi Eun; Jeong, Haeyoung; Jo, Sung Hee; Jeong, Jae Cheol; Kwon, Suk Yoon; An, Donghwan; Park, Jeong Mee

    2016-03-01

    Rhodococcus species have become increasingly important owing to their ability to degrade a wide range of toxic chemicals and produce bioactive compounds. Here, we report isolation of the Rhodococcus sp. KB6, which is a new leaf-inhabiting endophytic bacterium that suppresses black rot disease in sweet potato leaves. We determined the 7.0 Mb draft genome sequence of KB6 and have predicted 19 biosynthetic gene clusters for secondary metabolites, including heterobactins, which are a new class of siderophores. Notably, we showed the first internal colonization of host plants with Rhodococcus sp. KB6 and discuss its potential as a biocontrol agent for sustainable agriculture. PMID:26767576

  3. Insight on RDX degradation mechanism by Rhodococcus strains using 13C and 15N kinetic isotope effects.

    PubMed

    Bernstein, Anat; Ronen, Zeev; Gelman, Faina

    2013-01-01

    The explosive Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is known to be degraded aerobically by various isolates of the Rhodococcus species, with denitration being the key step, mediated by Cytochrome P450. Our study aimed at gaining insight into the RDX degradation mechanism by Rhodococcus species and comparing isotope effects associated with RDX degradation by distinct Rhodococcus strains. For these purposes, enrichment in (13)C and (15)N isotopes throughout RDX denitration was studied for three distinct Rhodococcus strains, isolated from soil and groundwater in an RDX-contaminated site. The observable (15)N enrichment throughout the reaction, together with minor (13)C enrichment, suggests that N-N bond cleavage is likely to be the key rate-limiting step in the reaction. The similarity in the kinetic (15)N isotope effect between the three tested strains suggests that either isotope-masking effects are negligible, or are of a similar extent for all tested strains. The lack of variability in the kinetic (15)N isotope effect allows the interpretation of environmental studies with greater confidence. PMID:23215036

  4. Nonhealing Wound Due to Rhodococcus equi in an Apparently Immunocompetent Patient, Revealing CD8+ T-Lymphocyte Deficiency ▿

    PubMed Central

    Denes, Eric; Peignon-Orsoni, Dominique; Terrade, François-Xavier

    2010-01-01

    We describe a case of a nonhealing wound due to Rhodococcus equi. Failure of the wound to heal led to immunological investigations and the discovery of a previously unknown CD8+ T-lymphocyte deficit responsible for the chronic infection. The infection was cured after a 3-month course of a combination of antibiotics. PMID:20881171

  5. In vitro activities of polycationic peptides alone and in combination with clinically used antimicrobial agents against Rhodococcus equi.

    PubMed

    Giacometti, A; Cirioni, O; Ancarani, F; Del Prete, M S; Fortuna, M; Scalise, G

    1999-08-01

    The in vitro activities of magainin II, nisin, and ranalexin alone and in combination with other antimicrobial agents against six clinical isolates of Rhodococcus equi were investigated by MIC and time-kill studies. All isolates were more susceptible to nisin. A positive interaction was observed when the peptides were combined with ampicillin, ceftriaxone, rifabutin, rifampin, azithromycin, clarithromycin, and vancomycin. PMID:10428947

  6. Gene Cloning and Nucleotide Sequencing and Properties of a Cocaine Esterase from Rhodococcus sp. Strain MB1

    PubMed Central

    Bresler, Matthew M.; Rosser, Susan J.; Basran, Amrik; Bruce, Neil C.

    2000-01-01

    A strain of Rhodococcus designated MB1, which was capable of utilizing cocaine as a sole source of carbon and nitrogen for growth, was isolated from rhizosphere soil of the tropane alkaloid-producing plant Erythroxylum coca. A cocaine esterase was found to initiate degradation of cocaine, which was hydrolyzed to ecgonine methyl ester and benzoate; both of these esterolytic products were further metabolized by Rhodococcus sp. strain MB1. The structural gene encoding a cocaine esterase, designated cocE, was cloned from Rhodococcus sp. strain MB1 genomic libraries by screening recombinant strains of Rhodococcus erythropolis CW25 for growth on cocaine. The nucleotide sequence of cocE corresponded to an open reading frame of 1,724 bp that codes for a protein of 574 amino acids. The amino acid sequence of cocaine esterase has a region of similarity with the active serine consensus of X-prolyl dipeptidyl aminopeptidases, suggesting that the cocaine esterase is a serine esterase. The cocE coding sequence was subcloned into the pCFX1 expression plasmid and expressed in Escherichia coli. The recombinant cocaine esterase was purified to apparent homogeneity and was found to be monomeric, with an Mr of approximately 65,000. The apparent Km of the enzyme (mean ± standard deviation) for cocaine was measured as 1.33 ± 0.085 mM. These findings are of potential use in the development of a linked assay for the detection of illicit cocaine. PMID:10698749

  7. Transfer of the virulence-associated protein A-bearing plasmid between field strains of virulent and avirulent Rhodococcus equi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virulent and avirulent isolates coexist in equine feces and the environment and serve as a source of infection for foals. The extent to which conjugative plasmid transfer occurs between these strains is unknown and is important for understanding the epidemiology of Rhodococcus equi infections of fo...

  8. Sequence and molecular characterization of a DNA region encoding the dibenzothiophene desulfurization operon of Rhodococcus sp. strain IGTS8.

    PubMed Central

    Piddington, C S; Kovacevich, B R; Rambosek, J

    1995-01-01

    Dibenzothiophene (DBT), a model compound for sulfur-containing organic molecules found in fossil fuels, can be desulfurized to 2-hydroxybiphenyl (2-HBP) by Rhodococcus sp. strain IGTS8. Complementation of a desulfurization (dsz) mutant provided the genes from Rhodococcus sp. strain IGTS8 responsible for desulfurization. A 6.7-kb TaqI fragment cloned in Escherichia coli-Rhodococcus shuttle vector pRR-6 was found to both complement this mutation and confer desulfurization to Rhodococcus fascians, which normally is not able to desulfurize DBT. Expression of this fragment in E. coli also conferred the ability to desulfurize DBT. A molecular analysis of the cloned fragment revealed a single operon containing three open reading frames involved in the conversion of DBT to 2-HBP. The three genes were designated dszA, dszB, and dszC. Neither the nucleotide sequences nor the deduced amino acid sequences of the enzymes exhibited significant similarity to sequences obtained from the GenBank, EMBL, and Swiss-Prot databases, indicating that these enzymes are novel enzymes. Subclone analyses revealed that the gene product of dszC converts DBT directly to DBT-sulfone and that the gene products of dszA and dszB act in concert to convert DBT-sulfone to 2-HBP. PMID:7574582

  9. Draft Genome Sequence of the Piezotolerant and Crude Oil-Degrading Bacterium Rhodococcus qingshengii Strain TUHH-12

    PubMed Central

    Hamilton, Trinity L.; Valladares Juárez, Ana Gabriela; Schedler, Martina; Macalady, Jennifer L.; Müller, Rudolf; Freeman, Katherine H.

    2015-01-01

    We report here the draft genome sequence of Rhodococcus qingshengii strain TUHH-12. The ability of this piezotolerant bacterium to grow on crude oil and tetracosane as sole carbon sources at 150 × 105 Pa makes it useful in studies of hydrocarbon degradation under simulated deep-sea conditions. PMID:25858843

  10. Metagenome Sequencing Revealed Rhodococcus Dominance in Farpuk Cave, Mizoram, India, an Eastern Himalayan Biodiversity Hot Spot Region

    PubMed Central

    De Mandal, Surajit; Sanga, Zothan

    2015-01-01

    The present study employed 16S rRNA amplicon sequencing to survey the prokaryotic microbiota on Farpuk Cave, revealing a diverse bacterial community with 4,021 operational taxonomical units (OTUs), mainly dominated by the genus Rhodococcus. Moreover, 18.17% of the OTUs were unclassified at the phylum level, suggesting the existence of novel bacterial species. PMID:26067958

  11. Attempts to find phenotypic markers of the virulence plasmid of Rhodococcus equi.

    PubMed Central

    De La Peña-Moctezuma, A; Prescott, J F; Goodfellow, M

    1996-01-01

    Four isolates of Rhodococcus equi, from pneumonic foals, and containing the 85 kb virulence plasmid, a porcine isolate containing an 80 kb plasmid, and their plasmid cured derivatives, were examined for 239 phenotypic properties in an attempt to find characters other than the virulence-associated protein (VapA) which might be encoded by the virulence plasmid in organisms grown at 37 degrees C. Tests chosen included those which have previously given variable results for R. equi isolates, since such variability might be attributed to plasmid curing, and characteristics which have been described as properties of plasmids of Rhodococcus species other than R. equi. Tests included cadmium resistance, Congo red binding, resistance to 26 antibiotics, conventional clinical microbiological tests, utilization of 95 different carbon sources, enzymatic activities in API ZYM, fluorogenic assays for exo- and endopeptidase, glycosidase activities, and testosterone degradation. Apart from production of VapA by foal isolates, no phenotypic property was identified in the plasmid-positive isolates. Phenotypic characteristics of R. equi that have not been described before, and might be useful in identification were: metabolism of N-acetyl-beta D-glucopyranoside, alpha- and beta-hydroxybutyric, alpha-ketobutyric and N-acetyl-glutamic acids, of methylpyruvate, heptanoate, nonanoate and stearate esters; exopeptidase activity against alanine-alanine-tyrosine, alanine-phenylalanine-lysine, glycine-arginine, lysine-alanine, and valine-glycine-alanine; endopeptidase activity against arginine and methionine; and hydrolysis of bis-phosphate ester. PMID:8825990

  12. Coexisting bacterial populations responsible for multiphasic mineralization kinetics in soil. [Janthinobacterium sp. Rhodococcus sp

    SciTech Connect

    Schmidt, S.K.; Gier, M.J. )

    1990-09-01

    Experiments were conducted to study populations of indigenous microorganisms capable of mineralizing 2,4-dinitrophenol (DNP) in two soils. Previous kinetic analyses indicated the presence of two coexisting populations of DNP-mineralizing microorganisms in a forest soil (soil 1). Studies in which eucaryotic and procaryotic inhibitors were added to this soil indicated that both populations were bacterial. Most-probable-number counts with media containing different concentrations of DNP indicated that more bacteria could mineralize low concentrations of DNP than could metabolize high concentrations of it. Enrichments with varying concentrations of DNP and various combinations of inhibitors consistently resulted in the isolation of the same two species of bacteria from soil 1. This soil contained a large number and variety of fungi, but no fungi capable of mineralizing DNP were isolated. The two bacterial isolates were identified as a Janthinobacterium sp. and a Rhodococcus sp. The Janthinobacterium sp. had a low {mu}{sub max} and a low K{sub m} for DNP mineralization, whereas the Rhodococcus sp. had much higher values for both parameters. These differences between the two species of bacteria were similar to differences seen when soil was incubated with different concentrations of DNP. Values for {mu}{sub max} from soil incubations were similar to {mu}{sub max} values obtained in pure culture studies. In contrast, K{sub s} and K{sub m} values showed greater variation between soil and pure culture studies.

  13. Combination of degradation pathways for naphthalene utilization in Rhodococcus sp. strain TFB.

    PubMed

    Tomás-Gallardo, Laura; Gómez-Álvarez, Helena; Santero, Eduardo; Floriano, Belén

    2014-03-01

    Rhodococcus sp. strain TFB is a metabolic versatile bacterium able to grow on naphthalene as the only carbon and energy source. Applying proteomic, genetic and biochemical approaches, we propose in this paper that, at least, three coordinated but independently regulated set of genes are combined to degrade naphthalene in TFB. First, proteins involved in tetralin degradation are also induced by naphthalene and may carry out its conversion to salicylaldehyde. This is the only part of the naphthalene degradation pathway showing glucose catabolite repression. Second, a salicylaldehyde dehydrogenase activity that converts salicylaldehyde to salicylate is detected in naphthalene-grown cells but not in tetralin- or salicylate-grown cells. Finally, we describe the chromosomally located nag genes, encoding the gentisate pathway for salicylate conversion into fumarate and pyruvate, which are only induced by salicylate and not by naphthalene. This work shows how biodegradation pathways in Rhodococcus sp. strain TFB could be assembled using elements from different pathways mainly because of the laxity of the regulatory systems and the broad specificity of the catabolic enzymes. PMID:24325207

  14. Enhanced biofilm production by a toluene-degrading Rhodococcus observed after exposure to perfluoroalkyl acids.

    PubMed

    Weathers, Tess S; Higgins, Christopher P; Sharp, Jonathan O

    2015-05-01

    This study focuses on interactions between aerobic soil-derived hydrocarbon degrading bacteria and a suite of perfluorocarboxylic acids and perfluoroalkylsulfonates that are found in aqueous film-forming foams used for fire suppression. No effect on toluene degradation rate or induction time was observed when active cells of Rhodococcus jostii strain RHA1 were exposed to toluene and a mixture of perfluoroalkyl acids (PFAAs) including perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) at concentrations near the upper bounds of groundwater relevance (11 PFAAs at 10 mg/L each). However, exposure to aqueous PFAA concentrations above 2 mg/L (each) was associated with enhanced aggregation of bacterial cells and significant increases in extracellular polymeric substance production. Flocculation was only observed during exponential growth and not elicited when PFAAs were added to resting incubations; analogous flocculation was also observed in soil enrichments. Aggregation was accompanied by 2- to 3-fold upregulation of stress-associated genes, sigF3 and prmA, during growth of this Rhodococcus in the presence of PFAAs. These results suggest that biological responses, such as microbial stress and biofilm formation, could be more prominent than suppression of co-contaminant biodegradation in subsurface locations where poly- and perfluoroalkyl substances occur with hydrocarbon fuels. PMID:25806435

  15. Influence of Rhodococcus equi on the respiratory burst of resident alveolar macrophages from horses

    SciTech Connect

    Brumbaugh, G.W.

    1986-01-01

    Rhodococcus equi is the etiologic agent of a devastating pneumonia of sporadic incidence in foals. The purpose of this study was to evaluate the influence of R. equi on the superoxide anion production, measured spectrophotometrically as the reduction of cytochrome C, and hexose monophosphate shunt activity, measured by /sup 14/CO/sub 2/ liberation from /sup 14/C-1-D-glucose, of alveolar macrophages from horses. Alveolar macrophages were harvested from 6 anesthetized, healthy, light-breed, adult horses by bronchoalveolar lavage. Following a randomized complete block design, the suspension of cells was divided into aliquots of 10/sup 6/ viable alveolar macrophages which were exposed to 1, 10 or 100 g. of opsonized R. equi or opsonized zymosan A at 37 C for 2 hours. In this study the respiratory burst of equine alveolar macrophages was only evidenced by the hexose monophosphate shunt activity and superoxide anion was not coincidentally produced. Rhodococcus equi did not adversely affect that response. The insignificant superoxide anion production by the alveolar macrophages suggests that this may not be a significant oxygen metabolite in those cells.

  16. Whole-Genome Shotgun Sequencing of Rhodococcus erythropolis Strain P27, a Highly Radiation-Resistant Actinomycete from Antarctica

    PubMed Central

    Gouvêa Taketani, Rodrigo; Domingues Zucchi, Tiago; Soares de Melo, Itamar

    2013-01-01

    Here, we report the draft genome sequence of radiation-resistant Rhodococcus erythropolis strain P27, isolated from leaves of Deschampsia antarctica Desv. (Poaceae) in the Admiralty Bay area, Antarctica. PMID:24072865

  17. Cold adaptive traits revealed by comparative genomic analysis of the eurypsychrophile Rhodococcus sp. JG3 isolated from high elevation McMurdo Dry Valley permafrost, Antarctica.

    PubMed

    Goordial, Jacqueline; Raymond-Bouchard, Isabelle; Zolotarov, Yevgen; de Bethencourt, Luis; Ronholm, Jennifer; Shapiro, Nicole; Woyke, Tanja; Stromvik, Martina; Greer, Charles W; Bakermans, Corien; Whyte, Lyle

    2016-02-01

    The permafrost soils of the high elevation McMurdo Dry Valleys are the most cold, desiccating and oligotrophic on Earth. Rhodococcus sp. JG3 is one of very few bacterial isolates from Antarctic Dry Valley permafrost, and displays subzero growth down to -5°C. To understand how Rhodococcus sp. JG3 is able to survive extreme permafrost conditions and be metabolically active at subzero temperatures, we sequenced its genome and compared it to the genomes of 14 mesophilic rhodococci. Rhodococcus sp. JG3 possessed a higher copy number of genes for general stress response, UV protection and protection from cold shock, osmotic stress and oxidative stress. We characterized genome wide molecular adaptations to cold, and identified genes that had amino acid compositions favourable for increased flexibility and functionality at low temperatures. Rhodococcus sp. JG3 possesses multiple complimentary strategies which may enable its survival in some of the harshest permafrost on Earth. PMID:26637477

  18. A physical map of the 85 kb virulence plasmid of Rhodococcus equi 103.

    PubMed Central

    de la Peña-Moctezuma, A; Prescott, J F

    1995-01-01

    A physical map of the 85 kb virulence plasmid pOTS from Rhodococcus equi 103 was constructed. The restriction map contains 2 AsnI, 5 BglII, 9 EcoRI, 4 HindIII, and 3 XbaI sites. The positions of the EcoRI and HindIII of pOTS are identical to that of the 85 kb virulence plasmid of R. equi ATCC 33701 reported recently by others. EcoRI restriction fragment sizes were similar in the 85 kb plasmids isolated from 4 horse derived R. equi but, except apparently for the 28.3 and possibly 2.0 and 1.5 kb fragments, were different in an 80.1 kb plasmid isolated from a pig source R. equi. PMID:8521357

  19. Detection of genes for alkane and naphthalene catabolism in Rhodococcus sp. strain 1BN.

    PubMed

    Andreoni, V; Bernasconi, S; Colombo, M; van Beilen, J B; Cavalca, L

    2000-10-01

    Rhodococcus sp. 1BN was isolated from a contaminated site and showed various biodegradative capabilities. Besides naphthalene, strain 1BN degraded medium- (C6) and long-chain alkanes (C16-C28), benzene and toluene, alone or when the hydrocarbons were mixed in equal proportions. The nucleotide sequence of an alk polymerase chain reaction (PCR) fragment revealed a 59% nucleotide homology to the Pseudomonas oleovorans alkB gene. The nar fragments were highly homologous to genes coding for large and small subunits of cis-naphthalene 1,2-dioxygenase (narAa and narAb) and to cis-naphthalene dihydrodiol dehydrogenase (narB) from other rhodococci. The oxidation of indene to cis-(1S,2R)-1,2-dihydroxyindan by toluene-induced cells allows to hypothesize that strain 1BN also carries a toluene dioxygenase-like system. PMID:11233165

  20. Identification of fluoropyrogallols as new intermediates in biotransformation of monofluorophenols in Rhodococcus opacus 1cp

    SciTech Connect

    Finkelstein, Z.I.; Baskunov, B.P.; Boersma, M.G.; Vervoort, J.; Golovlev, E.L.; Berkel, W.J.H. van; Golovleva, L.A.; Rietjens, I.M.C.M.

    2000-05-01

    The transformation of monofluorophenols by whole cells of Rhodococcus opacus 1cp was investigated, with special emphasis on the nature of hydroxylated intermediates formed. Thin-layer chromatography, mass spectrum analysis, and {sup 19}F nuclear magnetic resonance demonstrated the formation of fluorocatechol and trihydroxyfluorobenzene derivatives from each of three monofluorophenols. The {sup 19}F chemical shifts and proton-coupled splitting patterns of the fluorine resonances of the trihydroxyfluorobenzene products established that the trihydroxylated aromatic metabolites contained hydroxyl substituents on three adjacent carbon atoms. Thus, formation of 1,2,3-trihydroxy-4-fluorobenzene (4-fluoropyrogallol) from 2-fluorophenol and formation of 1,2,3-trihydroxy-5-fluorobenzene (5-fluoropyrogallol) from 3-fluorophenol and 4-fluorophenol were observed. These results indicate the involvement of fluoropyrogallols as previously unidentified metabolites in the biotransformation of monofluorophenols in R. opacus 1cp.

  1. Desulfurization and denitrogenation of heavy gas oil by Rhodococcus erythropolis ATCC 4277.

    PubMed

    Maass, D; Todescato, D; Moritz, D E; Oliveira, J Vladimir; Oliveira, D; Ulson de Souza, A A; Guelli Souza, S M A

    2015-08-01

    Some of the noxious atmospheric pollutants such as nitrogen and sulfur dioxides come from the fossil fuel combustion. Biodesulfurization and biodenitrogenation are processes which remove those pollutants through the action of microorganisms. The ability of sulfur and nitrogen removal by the strain Rhodococcus erythropolis ATCC 4277 was tested in a biphasic system containing different heavy gas oil concentrations in a batch reactor. Heavy gas oil is an important fraction of petroleum, because after passing through, the vacuum distillation is incorporated into diesel oil. This strain was able to remove about 40% of the nitrogen and sulfur present in the gas heavy oil. Additionally, no growth inhibition occurred even when in the presence of pure heavy gas oil. Results present in this work are considered relevant for the development of biocatalytic processes for nitrogen and sulfur removal toward building feasible industrial applications. PMID:25759162

  2. Rhodococcus equi pneumonia and sepsis in an allogeneic haematopoietic stem cell transplant recipient

    PubMed Central

    Shahani, Lokesh

    2014-01-01

    Rhodococcus equi is an aerobic facultative intracellular organism that is known to infect cells of the macrophage–monocyte lineage. It is a common veterinary pathogen; however, the incidence of this infection in humans has risen and it has been recognised as an emerging opportunistic pathogen among the immunocompromised patients. We present the case of a patient with chronic myeloid leukaemia who had received allogenic stem cell transplant and presented to the hospital with clinical picture of pneumonia. Her condition worsened on initial broad spectrum antimicrobials and 3 weeks into her hospitalisation, R. equi was isolated from her broncheoalveolar lavage and blood cultures. Based on the susceptibility, therapy was changed to four active antimicrobials; however, the patient failed to improve and eventually died. This case highlights the importance of considering the diagnosis of R. equi among immunosuppressed patients early in the right clinical setting due to the high virulence associated with this organism. PMID:24943142

  3. Nitrile Hydratase and Amidase from Rhodococcus rhodochrous Hydrolyze Acrylic Fibers and Granular Polyacrylonitriles

    PubMed Central

    Tauber, M. M.; Cavaco-Paulo, A.; Robra, K.-H.; Gübitz, G. M.

    2000-01-01

    Rhodococcus rhodochrous NCIMB 11216 produced nitrile hydratase (320 nkat mg of protein−1) and amidase activity (38.4 nkat mg of protein−1) when grown on a medium containing propionitrile. These enzymes were able to hydrolyze nitrile groups of both granular polyacrylonitriles (PAN) and acrylic fibers. Nitrile groups of PAN40 (molecular mass, 40 kDa) and PAN190 (molecular mass, 190 kDa) were converted into the corresponding carbonic acids to 1.8 and 1.0%, respectively. In contrast, surfacial nitrile groups of acrylic fibers were only converted to the corresponding amides. X-ray photoelectron spectroscopy analysis showed that 16% of the surfacial nitrile groups were hydrolyzed by the R. rhodochrous enzymes. Due to the enzymatic modification, the acrylic fibers became more hydrophilic and thus, adsorption of dyes was enhanced. This was indicated by a 15% increase in the staining level (K/S value) for C.I. Basic Blue 9. PMID:10742253

  4. Antibiotic failure in a renal transplant patient with Rhodococcus equi infection: an indication for surgical lobectomy.

    PubMed

    Ursales, A; Klein, J A; Beal, S G; Koch, M; Clement-Kruzel, S; Melton, L B; Spak, C W

    2014-12-01

    Rhodococcus equi is an animal pathogen that causes infrequent but challenging infections in immunocompromised individuals, few of which have been described in solid organ transplant recipients. Common clinical presentations include indolent cough, fever, and dyspnea, with necrotizing pneumonia and cavitation. We report a case of a dense right upper lung pneumonia with resultant R. equi bacteremia in a renal transplant recipient. Our patient initially responded to antibiotic treatment with resolution of bacteremia and clinical recovery, followed by interval progression in her right upper lobe consolidation on follow-up computed tomography scans. She underwent lobectomy for definitive therapy with resolution of symptoms. Lobectomy can be utilized in isolated infection after antibiotic failure with excellent clinical outcomes. PMID:25412764

  5. [Genetics and biochemistry of surfactant synthesis in Rhodococcus sp. H13-A]. Final report

    SciTech Connect

    Not Available

    1989-12-31

    The rationale for these studies resides is that biosurfactant synthesis occurs only when cells are grown with alkanes as sole source of carbon and energy. It is reasoned that biosurfactant synthesis is linked genetically to alkane oxidation and that the identification and characterization of the alk genes would provide information about the structural and regulator genes involved, in biosurfactant synthesis. Rhodococcus H13-A chromosomal DNA was isolated and digested with the restriction endonuclease Sau3A. The shuttle vector, pMVS301, was single site cleaved with Bgl II, phosphorylated, and the chromosomal DNA fragments agated into linearized pMVS301. The ligation mixture was used to transform competent E. coli HB101. The chromosomal DNA fragment has been cloned into pMVS301 which appears to contain genes encoding the initial oxidation of alkane. Electrophoration of Rhodococaus indicates transformation by this technique. Further studies are required to optimize conditions.

  6. (Genetics and biochemistry of surfactant synthesis in Rhodococcus sp. H13-A)

    SciTech Connect

    Not Available

    1989-01-01

    The rationale for these studies resides is that biosurfactant synthesis occurs only when cells are grown with alkanes as sole source of carbon and energy. It is reasoned that biosurfactant synthesis is linked genetically to alkane oxidation and that the identification and characterization of the alk genes would provide information about the structural and regulator genes involved, in biosurfactant synthesis. Rhodococcus H13-A chromosomal DNA was isolated and digested with the restriction endonuclease Sau3A. The shuttle vector, pMVS301, was single site cleaved with Bgl II, phosphorylated, and the chromosomal DNA fragments agated into linearized pMVS301. The ligation mixture was used to transform competent E. coli HB101. The chromosomal DNA fragment has been cloned into pMVS301 which appears to contain genes encoding the initial oxidation of alkane. Electrophoration of Rhodococaus indicates transformation by this technique. Further studies are required to optimize conditions.

  7. Enzymatic degradation of aliphatic nitriles by Rhodococcus rhodochrous BX2, a versatile nitrile-degrading bacterium.

    PubMed

    Fang, Shumei; An, Xuejiao; Liu, Hongyuan; Cheng, Yi; Hou, Ning; Feng, Lu; Huang, Xinning; Li, Chunyan

    2015-06-01

    Nitriles are common environmental pollutants, and their removal has attracted increasing attention. Microbial degradation is considered to be the most acceptable method for removal. In this work, we investigated the biodegradation of three aliphatic nitriles (acetonitrile, acrylonitrile and crotononitrile) by Rhodococcus rhodochrous BX2 and the expression of their corresponding metabolic enzymes. This organism can utilize all three aliphatic nitriles as sole carbon and nitrogen sources, resulting in the complete degradation of these compounds. The degradation kinetics were described using a first-order model. The degradation efficiency was ranked according to t1/2 as follows: acetonitrile>trans-crotononitrile>acrylonitrile>cis-crotononitrile. Only ammonia accumulated following the three nitriles degradation, while amides and carboxylic acids were transient and disappeared by the end of the assay. mRNA expression and enzyme activity indicated that the tested aliphatic nitriles were degraded via both the inducible NHase/amidase and the constitutive nitrilase pathways, with the former most likely preferred. PMID:25746475

  8. VapI, a new member of the Rhodococcus equi Vap family.

    PubMed

    Polidori, Marco; Haas, Albert

    2006-10-01

    Rhodococcus equi is a facultative intracellular bacterium which can cause bronchopneumonia in foals and AIDS patients. In this report we show that the ORF13-protein coded by the virulence associated plasmid of R. equi is clearly homologous to VapE. Nucleotide sequence analysis revealed frame shift mutations that shorten the sequence of the ORF13-protein. A theoretical extension of the sequence of ORF13 by the introduction of a single nucleotide yields a translated amino acid sequence that is highly homologous to VapE and other members of the Vap family. The data provided in this study indicate that the ORF13-protein is a novel member of the Vap family and is therefore designated VapI. PMID:16871422

  9. Structure of the virulence-associated protein VapD from the intracellular pathogen Rhodococcus equi

    SciTech Connect

    Whittingham, Jean L.; Blagova, Elena V.; Finn, Ciaran E.; Luo, Haixia; Miranda-CasoLuengo, Raúl; Turkenburg, Johan P.; Leech, Andrew P.; Walton, Paul H.; Murzin, Alexey G.; Meijer, Wim G.; Wilkinson, Anthony J.

    2014-08-01

    VapD is one of a set of highly homologous virulence-associated proteins from the multi-host pathogen Rhodococcus equi. The crystal structure reveals an eight-stranded β-barrel with a novel fold and a glycine rich ‘bald’ surface. Rhodococcus equi is a multi-host pathogen that infects a range of animals as well as immune-compromised humans. Equine and porcine isolates harbour a virulence plasmid encoding a homologous family of virulence-associated proteins associated with the capacity of R. equi to divert the normal processes of endosomal maturation, enabling bacterial survival and proliferation in alveolar macrophages. To provide a basis for probing the function of the Vap proteins in virulence, the crystal structure of VapD was determined. VapD is a monomer as determined by multi-angle laser light scattering. The structure reveals an elliptical, compact eight-stranded β-barrel with a novel strand topology and pseudo-twofold symmetry, suggesting evolution from an ancestral dimer. Surface-associated octyl-β-d-glucoside molecules may provide clues to function. Circular-dichroism spectroscopic analysis suggests that the β-barrel structure is preceded by a natively disordered region at the N-terminus. Sequence comparisons indicate that the core folds of the other plasmid-encoded virulence-associated proteins from R. equi strains are similar to that of VapD. It is further shown that sequences encoding putative R. equi Vap-like proteins occur in diverse bacterial species. Finally, the functional implications of the structure are discussed in the light of the unique structural features of VapD and its partial structural similarity to other β-barrel proteins.

  10. Biodegradation of the Organic Disulfide 4,4′-Dithiodibutyric Acid by Rhodococcus spp.

    PubMed Central

    Khairy, Heba; Wübbeler, Jan Hendrik

    2015-01-01

    Four Rhodococcus spp. exhibited the ability to use 4,4′-dithiodibutyric acid (DTDB) as a sole carbon source for growth. The most important step for the production of a novel polythioester (PTE) using DTDB as a precursor substrate is the initial cleavage of DTDB. Thus, identification of the enzyme responsible for this step was mandatory. Because Rhodococcus erythropolis strain MI2 serves as a model organism for elucidation of the biodegradation of DTDB, it was used to identify the genes encoding the enzymes involved in DTDB utilization. To identify these genes, transposon mutagenesis of R. erythropolis MI2 was carried out using transposon pTNR-TA. Among 3,261 mutants screened, 8 showed no growth with DTDB as the sole carbon source. In five mutants, the insertion locus was mapped either within a gene coding for a polysaccharide deacetyltransferase, a putative ATPase, or an acetyl coenzyme A transferase, 1 bp upstream of a gene coding for a putative methylase, or 176 bp downstream of a gene coding for a putative kinase. In another mutant, the insertion was localized between genes encoding a putative transcriptional regulator of the TetR family (noxR) and an NADH:flavin oxidoreductase (nox). Moreover, in two other mutants, the insertion loci were mapped within a gene encoding a hypothetical protein in the vicinity of noxR and nox. The interruption mutant generated, R. erythropolis MI2 noxΩtsr, was unable to grow with DTDB as the sole carbon source. Subsequently, nox was overexpressed and purified, and its activity with DTDB was measured. The specific enzyme activity of Nox amounted to 1.2 ± 0.15 U/mg. Therefore, we propose that Nox is responsible for the initial cleavage of DTDB into 2 molecules of 4-mercaptobutyric acid (4MB). PMID:26407888

  11. The genome of a pathogenic rhodococcus: cooptive virulence underpinned by key gene acquisitions.

    PubMed

    Letek, Michal; González, Patricia; Macarthur, Iain; Rodríguez, Héctor; Freeman, Tom C; Valero-Rello, Ana; Blanco, Mónica; Buckley, Tom; Cherevach, Inna; Fahey, Ruth; Hapeshi, Alexia; Holdstock, Jolyon; Leadon, Desmond; Navas, Jesús; Ocampo, Alain; Quail, Michael A; Sanders, Mandy; Scortti, Mariela M; Prescott, John F; Fogarty, Ursula; Meijer, Wim G; Parkhill, Julian; Bentley, Stephen D; Vázquez-Boland, José A

    2010-09-01

    We report the genome of the facultative intracellular parasite Rhodococcus equi, the only animal pathogen within the biotechnologically important actinobacterial genus Rhodococcus. The 5.0-Mb R. equi 103S genome is significantly smaller than those of environmental rhodococci. This is due to genome expansion in nonpathogenic species, via a linear gain of paralogous genes and an accelerated genetic flux, rather than reductive evolution in R. equi. The 103S genome lacks the extensive catabolic and secondary metabolic complement of environmental rhodococci, and it displays unique adaptations for host colonization and competition in the short-chain fatty acid-rich intestine and manure of herbivores--two main R. equi reservoirs. Except for a few horizontally acquired (HGT) pathogenicity loci, including a cytoadhesive pilus determinant (rpl) and the virulence plasmid vap pathogenicity island (PAI) required for intramacrophage survival, most of the potential virulence-associated genes identified in R. equi are conserved in environmental rhodococci or have homologs in nonpathogenic Actinobacteria. This suggests a mechanism of virulence evolution based on the cooption of existing core actinobacterial traits, triggered by key host niche-adaptive HGT events. We tested this hypothesis by investigating R. equi virulence plasmid-chromosome crosstalk, by global transcription profiling and expression network analysis. Two chromosomal genes conserved in environmental rhodococci, encoding putative chorismate mutase and anthranilate synthase enzymes involved in aromatic amino acid biosynthesis, were strongly coregulated with vap PAI virulence genes and required for optimal proliferation in macrophages. The regulatory integration of chromosomal metabolic genes under the control of the HGT-acquired plasmid PAI is thus an important element in the cooptive virulence of R. equi. PMID:20941392

  12. The Genome of a Pathogenic Rhodococcus: Cooptive Virulence Underpinned by Key Gene Acquisitions

    PubMed Central

    Letek, Michal; González, Patricia; MacArthur, Iain; Rodríguez, Héctor; Freeman, Tom C.; Valero-Rello, Ana; Blanco, Mónica; Buckley, Tom; Cherevach, Inna; Fahey, Ruth; Hapeshi, Alexia; Holdstock, Jolyon; Leadon, Desmond; Navas, Jesús; Ocampo, Alain; Quail, Michael A.; Sanders, Mandy; Scortti, Mariela M.; Prescott, John F.; Fogarty, Ursula; Meijer, Wim G.; Parkhill, Julian; Bentley, Stephen D.; Vázquez-Boland, José A.

    2010-01-01

    We report the genome of the facultative intracellular parasite Rhodococcus equi, the only animal pathogen within the biotechnologically important actinobacterial genus Rhodococcus. The 5.0-Mb R. equi 103S genome is significantly smaller than those of environmental rhodococci. This is due to genome expansion in nonpathogenic species, via a linear gain of paralogous genes and an accelerated genetic flux, rather than reductive evolution in R. equi. The 103S genome lacks the extensive catabolic and secondary metabolic complement of environmental rhodococci, and it displays unique adaptations for host colonization and competition in the short-chain fatty acid–rich intestine and manure of herbivores—two main R. equi reservoirs. Except for a few horizontally acquired (HGT) pathogenicity loci, including a cytoadhesive pilus determinant (rpl) and the virulence plasmid vap pathogenicity island (PAI) required for intramacrophage survival, most of the potential virulence-associated genes identified in R. equi are conserved in environmental rhodococci or have homologs in nonpathogenic Actinobacteria. This suggests a mechanism of virulence evolution based on the cooption of existing core actinobacterial traits, triggered by key host niche–adaptive HGT events. We tested this hypothesis by investigating R. equi virulence plasmid-chromosome crosstalk, by global transcription profiling and expression network analysis. Two chromosomal genes conserved in environmental rhodococci, encoding putative chorismate mutase and anthranilate synthase enzymes involved in aromatic amino acid biosynthesis, were strongly coregulated with vap PAI virulence genes and required for optimal proliferation in macrophages. The regulatory integration of chromosomal metabolic genes under the control of the HGT–acquired plasmid PAI is thus an important element in the cooptive virulence of R. equi. PMID:20941392

  13. Expression and characterization of an N-oxygenase from Rhodococcus jostii RHAI.

    PubMed

    Indest, Karl J; Eberly, Jed O; Hancock, Dawn E

    2015-01-01

    Nitro group-containing natural products are rare in nature. There are few examples of N-oxygenases, enzymes that incorporate atmospheric oxygen into primary and secondary amines, characterized in the literature. N-oxygenases have yet to be characterized from the Corynebacterineae, a metabolically diverse group of organisms that includes the genera Rhodococcus, Gordonia, and Mycobacterium. A preliminary in silico search for N-oxygenase AurF gene orthologs revealed multiple protein candidates present in the genome of the Actinomycete Rhodococcus jostii RHAI (RHAI_ro06104). Towards the goal of identifying novel biocatalysts with potential utility for the biosynthesis of nitroaromatics, AurF ortholog RHAI_ro6104 was cloned, expressed and purified in E. coli and amine and nitro containing phenol substrates tested for activity. RHAI-ro06104 showed the highest activity with 4-aminophenol, producing a Vmax of 18.76 μM s(-1) and a Km of 15.29 mM and demonstrated significant activities with 2-aminophenol and 2-amino-5-methylphenol, producing a Vmax of 12.86 and 12.72 μM s(-1) with a Km of 8.34 and 2.81 mM, respectively. These findings are consistent with a substrate range observed in other N-oxygenases, which seem to accommodate substrates that lack halogenated substitutions and side groups directly flanking the amine group. Attempts to identify modulators of RHAI-ro06104 gene activity demonstrated that aromatic amino acids inhibit expression by almost 50%. PMID:26782651

  14. Isolation and identification of berberine and berberrubine metabolites by berberine-utilizing bacterium Rhodococcus sp. strain BD7100.

    PubMed

    Ishikawa, Kazuki; Takeda, Hisashi; Wakana, Daigo; Sato, Fumihiko; Hosoe, Tomoo

    2016-05-01

    Based on the finding of a novel berberine (BBR)-utilizing bacterium, Rhodococcus sp. strain BD7100, we investigated the degradation of BBR and its analog berberrubine (BRU). Resting cells of BD7100 demethylenated BBR and BRU, yielding benzeneacetic acid analogs. Isolation of benzeneacetic acid analogs suggested that BD7100 degraded the isoquinoline ring of the protoberberine skeleton. This work represents the first report of cleavage of protoberberine skeleton by a microorganism. PMID:26882131

  15. Genome Sequence of Rhodococcus sp. Strain PML026, a Trehalolipid Biosurfactant Producer and Biodegrader of Oil and Alkanes

    PubMed Central

    2015-01-01

    Rhodococcus sp. strain PML026 produces an array of trehalolipid biosurfactant compounds in order to utilize hydrophobic carbon sources, such as oils and alkanes. Here, we report the high-quality draft genome sequence of this strain, which has a total length of 5,168,404 bp containing 4,835 protein-coding sequences, 12 rRNAs, and 45 tRNAs. PMID:25953162

  16. Clinical application of a polymerase chain reaction assay in the diagnosis of pneumonia caused by Rhodococcus equi in a horse.

    PubMed

    Vivrette, S L; Sellon, D C; Gibbons, D S

    2000-11-01

    Diagnosis of pneumonia caused by Rhodococcus equi can be made more rapidly by use of a polymerase chain reaction (PCR) assay than by use of conventional bacteriologic culture techniques. Use of a PCR assay aids in the differentiation between virulent and avirulent strains of R equi, and the assay may be used to identify R equi in feces and soil of breeding farms. PMID:11061388

  17. Characterization of carbon-sulfur bond cleavage by axenic and mixed cultures of Rhodococcus rhodochrous IGTS8

    SciTech Connect

    Kayser, K.J.; Bielaga, B.A.; Jackowski, K.; Oduson, O.; Kilbane, J. II

    1992-12-31

    Growth assays reveal that Rhodococcus rhodochrous IGTS8 can utilize a wide range of organosulfur compounds as the sole source of sulfur. Compounds that are utilized include thiophenes, sulfides, disulfides, mercaptans, sulfoxides, and sulfones. None of the organosulfur compounds tested can serve as a carbon source. A convenient spectrophotometric assay (Gibbs assay) based on the chromogenic reaction of 2,6-dichloroquinone-4-chloroimide with aromatic hydroxyl groups was developed and used in conjunction with GC/MS analysis to examine the kinetics of carbon-sulfur bond cleavage by axenic and mixed cell cultures of Rhodococcus rhodochrous IGTS8. The desulfurization trait is expressed at uniform levels during the mid-exponential phase, reaches a maximum during idiophase, and then declines in stationary-phase cells. Desulfurization rates for dibenzothiophene (DBT) range from 8 to 15 {mu}M of DBT/10{sup 12} cells/hour. Mixtures of genetically marked Rhodococcus rhodochrous IGTS8 and an organisms incapable of cleaning carbon-sulfur bonds in relevant test compounds, Enterobacter cloacae, were prepared in ratios that varied over six orders of magnitude. Growth studies revealed that Enterobacter cloacae was able to gain access to sulfur liberated from organosulfur compounds by IGTS8; however, cell-to-cell contact was required. These data also indicate that the desulfurization activity of IGTS8 cells in mixed cultures may be as much as 200-fold higher than in axenic cultures.

  18. Analysis and optimization of triacylglycerol synthesis in novel oleaginous Rhodococcus and Streptomyces strains isolated from desert soil.

    PubMed

    Röttig, Annika; Hauschild, Philippa; Madkour, Mohamed H; Al-Ansari, Ahmed M; Almakishah, Naief H; Steinbüchel, Alexander

    2016-05-10

    As oleaginous microorganisms represent an upcoming novel feedstock for the biotechnological production of lipids or lipid-derived biofuels, we searched for novel, lipid-producing strains in desert soil. This was encouraged by the hypothesis that neutral lipids represent an ideal storage compound, especially under arid conditions, as several animals are known to outlast long periods in absence of drinking water by metabolizing their body fat. Ten lipid-accumulating bacterial strains, affiliated to the genera Bacillus, Cupriavidus, Nocardia, Rhodococcus and Streptomyces, were isolated from arid desert soil due to their ability to synthesize poly(β-hydroxybutyrate), triacylglycerols or wax esters. Particularly two Streptomyces sp. strains and one Rhodococcus sp. strain accumulate significant amounts of TAG under storage conditions under optimized cultivation conditions. Rhodococcus sp. A27 and Streptomyces sp. G49 synthesized approx. 30% (w/w) fatty acids from fructose or cellobiose, respectively, while Streptomyces isolate G25 reached a cellular fatty acid content of nearly 50% (w/w) when cultivated with cellobiose. The stored triacylglycerols were composed of 30-40% branched fatty acids, such as anteiso-pentadecanoic or iso-hexadecanoic acid. To date, this represents by far the highest lipid content described for streptomycetes. A biotechnological production of such lipids using (hemi)cellulose-derived raw material could be used to obtain sustainable biodiesel with a high proportion of branched-chain fatty acids to improve its cold-flow properties and oxidative stability. PMID:27034020

  19. Identification, characterization and molecular analysis of the viable but nonculturable Rhodococcus biphenylivorans

    PubMed Central

    Su, Xiaomei; Sun, Faqian; Wang, Yalin; Hashmi, Muhammad Zaffar; Guo, Li; Ding, Linxian; Shen, Chaofeng

    2015-01-01

    Numerous bacteria, including pollutant-degrading bacteria can enter the viable but nonculturable state (VBNC) when they encounter harsh environmental conditions. VBNC bacteria, as a vast majority of potent microbial resource can be of great significance in environmental rehabilitation. It is necessary to study the VBNC state of pollutant-degrading bacteria under various stress conditions. The aim of this study was to determine whether Rhodococcus biphenylivorans could enter the VBNC state under oligotrophic and low temperature conditions, and to examine the changes of morphology, enzymatic activity and gene expressions that might underline such state. The obtained results indicated that R. biphenylivorans TG9T could enter into the VBNC state and recover culturability under favorable environmental conditions. Results from Illumina high throughput RNA-sequencing revealed that the up-regulated genes related to ATP accumulation, protein modification, peptidoglycan biosynthesis and RNA polymerase were found in the VBNC cells, and the down-regulated genes mainly encoded hypothetical protein, membrane protein and NADH dehydrogenase subunit, which render VBNC cells more tolerant to survive under inhospitable conditions. This study provides new insights into prevention and control of the VBNC state of pollutant-degrading bacteria for their better capabilities in environmental rehabilitation. PMID:26687808

  20. A bifunctional enzyme from Rhodococcus erythropolis exhibiting secondary alcohol dehydrogenase-catalase activities.

    PubMed

    Martinez-Rojas, Enriqueta; Kurt, Tutku; Schmidt, Udo; Meyer, Vera; Garbe, Leif-Alexander

    2014-11-01

    Alcohol dehydrogenases have long been recognized as potential biocatalyst for production of chiral fine and bulk chemicals. They are relevant for industry in enantiospecific production of chiral compounds. In this study, we identified and purified a nicotinamide adenine dinucleotide (NAD)-dependent secondary alcohol dehydrogenase (SdcA) from Rhodococcus erythropolis oxidizing γ-lactols into γ-lactones. SdcA showed broad substrate specificity on γ-lactols; secondary aliphatic alcohols with 8 and 10 carbon atoms were also substrates and oxidized with (2S)-stereospecificity. The enzyme exhibited moderate stability with a half-life of 5 h at 40 °C and 20 days at 4 °C. Mass spectrometric identification revealed high sequence coverage of SdcA amino acid sequence to a highly conserved catalase from R. erythropolis. The corresponding encoding gene was isolated from genomic DNA and subsequently overexpressed in Escherichia coli BL21 DE3 cells. In addition, the recombinant SdcA was purified and characterized in order to confirm that the secondary alcohol dehydrogenase and catalase activity correspond to the same enzyme. PMID:24846734

  1. Prevalence and Antibiogram study of Rhodococcus equi in equines of Jammu and Kashmir, India

    PubMed Central

    MIR, Irfan Ahmad; KUMAR, Bablu; TAKU, Anil; BHARDWAJ, Rajinder Kumar; BHAT, Mohd Altaf; BADROO, Gulzar Ahmad

    2015-01-01

    ABSTRACT The present study was conducted to determine the prevalence of Rhodococcus equi infection in equines of Jammu and Kashmir, India, and evaluate the zoonotic threat posed by this organism to equine owners and tourists. One hundred and forty-one samples (98 samples from adult animals ≥5 years old and 43 samples from foals less than 6 months old) were collected in duplicate from nasopharyngeal tract of equines for isolation and direct PCR. A total of 12 isolates of R. equi were recovered, of which 9 were from foals and 3 from adult animals. Therefore, the present study recorded prevalence rates of 20.93% and 3.06% among foals and adult equines respectively. The prevalence rates were found to be 25.58% and 4.08% by 16S rRNA species-specific PCR among foals and adult animals respectively. Thus, the PCR-based assay was found to be more sensitive and helped in quick detection of R. equi than the culture based method which is time consuming and laborious. However, the culture-based method is still preferred due to some limitations of PCR. The antibiogram of the isolates revealed that erythromycin and rifampicin were the most effective antimicrobials with 100% sensitivity, followed by amoxicillin (66.67%), lincomycin (58.3%) and kanamycin (58.3%). The results also revealed that resistance was highest for penicillin G (50%), followed by kanamycin (25%) and streptomycin (25%). PMID:25829867

  2. Immunogenicity of an Electron Beam Inactivated Rhodococcus equi Vaccine in Neonatal Foals

    PubMed Central

    Bordin, Angela I.; Pillai, Suresh D.; Brake, Courtney; Bagley, Kaytee B.; Bourquin, Jessica R.; Coleman, Michelle; Oliveira, Fabiano N.; Mwangi, Waithaka; McMurray, David N.; Love, Charles C.; Felippe, Maria Julia B.; Cohen, Noah D.

    2014-01-01

    Rhodococcus equi is an important pathogen of foals that causes severe pneumonia. To date, there is no licensed vaccine effective against R. equi pneumonia of foals. The objectives of our study were to develop an electron beam (eBeam) inactivated vaccine against R. equi and evaluate its immunogenicity. A dose of eBeam irradiation that inactivated replication of R. equi while maintaining outer cell wall integrity was identified. Enteral administration of eBeam inactivated R. equi increased interferon-γ production by peripheral blood mononuclear cells in response to stimulation with virulent R. equi and generated naso-pharyngeal R. equi-specific IgA in newborn foals. Our results indicate that eBeam irradiated R. equi administered enterally produce cell-mediated and upper respiratory mucosal immune responses, in the face of passively transferred maternal antibodies, similar to those produced in response to enteral administration of live organisms (a strategy which previously has been documented to protect foals against intrabronchial infection with virulent R. equi). No evidence of adverse effects was noted among vaccinated foals. PMID:25153708

  3. Response of Rhodococcus erythropolis strain IBBPo1 to toxic organic solvents.

    PubMed

    Stancu, Mihaela Marilena

    2015-01-01

    Recently, there has been a lot of interest in the utilization of rhodococci in the bioremediation of petroleum contaminated environments. This study investigates the response of Rhodococcus erythropolis IBBPo1 cells to 1% organic solvents (alkanes, aromatics). A combination of microbiology, biochemical, and molecular approaches were used to examine cell adaptation mechanisms likely to be pursued by this strain after 1% organic solvent exposure. R. erythropolis IBBPo1 was found to utilize 1% alkanes (cyclohexane, n-hexane, n-decane) and aromatics (toluene, styrene, ethylbenzene) as the sole carbon source. Modifications in cell viability, cell morphology, membrane permeability, lipid profile, carotenoid pigments profile and 16S rRNA gene were revealed in R. erythropolis IBBPo1 cells grown 1 and 24 h on minimal medium in the presence of 1% alkanes (cyclohexane, n-hexane, n-decane) and aromatics (toluene, styrene, ethylbenzene). Due to its environmental origin and its metabolic potential, R. erythropolis IBBPo1 is an excellent candidate for the bioremediation of soils contaminated with crude oils and other toxic compounds. Moreover, the carotenoid pigments produced by this nonpathogenic Gram-positive bacterium have a variety of other potential applications. PMID:26691458

  4. Catabolic pathway of gamma-caprolactone in the biocontrol agent Rhodococcus erythropolis.

    PubMed

    Barbey, Corinne; Crépin, Alexandre; Cirou, Amélie; Budin-Verneuil, Aurélie; Orange, Nicole; Feuilloley, Marc; Faure, Denis; Dessaux, Yves; Burini, Jean-François; Latour, Xavier

    2012-01-01

    Gamma-caprolactone (GCL) is well-known as a food flavor and has been recently described as a biostimulant molecule promoting the growth of bacteria with biocontrol activity against soft-rot pathogens. Among these biocontrol agents, Rhodococcus erythropolis, characterized by a remarkable metabolic versatility, assimilates various γ-butyrolactone molecules with a branched-aliphatic chain, such as GCL. The assimilative pathway of GCL in R. erythropolis was investigated by two-dimensional gel electrophoresis coupled to matrix-assisted laser desorption ionization (MALDI) mass spectrometry (MS) analysis. This analysis suggests the involvement of the lactonase QsdA in ring-opening, a feature confirmed by heterologous expression in Escherichia coli. According to proteome analysis, the open-chain form of GCL was degraded by β- and ω-oxidation coupled to the Krebs cycle and β-ketoadipate pathway. Ubiquity of qsdA gene among environmental R. erythropolis isolates was verified by PCR. In addition to a previous N-acyl homoserine lactone catabolic function, QsdA may therefore be involved in an intermediate degradative step of cyclic recalcitrant molecules or in synthesis of flavoring lactones. PMID:22085026

  5. Mathematic modeling for optimum conditions on aflatoxin B₁degradation by the aerobic bacterium Rhodococcus erythropolis.

    PubMed

    Kong, Qing; Zhai, Cuiping; Guan, Bin; Li, Chunjuan; Shan, Shihua; Yu, Jiujiang

    2012-11-01

    Response surface methodology was employed to optimize the degradation conditions of AFB₁ by Rhodococcus erythropolis in liquid culture. The most important factors that influence the degradation, as identified by a two-level Plackett-Burman design with six variables, were temperature, pH, liquid volume, inoculum size, agitation speed and incubation time. Central composite design (CCD) and response surface analysis were used to further investigate the interactions between these variables and to optimize the degradation efficiency of R. erythropolis based on a second-order model. The results demonstrated that the optimal parameters were: temperature, 23.2 °C; pH, 7.17; liquid volume, 24.6 mL in 100-mL flask; inoculum size, 10%; agitation speed, 180 rpm; and incubation time, 81.9 h. Under these conditions, the degradation efficiency of R. erythropolis could reach 95.8% in liquid culture, which was increased by about three times as compared to non-optimized conditions. The result by mathematic modeling has great potential for aflatoxin removal in industrial fermentation such as in food processing and ethanol production. PMID:23202311

  6. Induction of Viable but Nonculturable State in Rhodococcus and Transcriptome Analysis Using RNA-seq.

    PubMed

    Su, Xiaomei; Guo, Li; Ding, Linxian; Qu, Kun; Shen, Chaofeng

    2016-01-01

    Viable but nonculturable (VBNC) bacteria, which maintain the viability with loss of culturability, universally exist in contaminated and non-contaminated environments. In this study, two strains, Rhodococcus sp. TG13 and TN3, which were isolated from PCB-contaminated sediment and non-contaminated sediment respectively, were investigated under low temperature and oligotrophic conditions. The results indicated that the two strains TG13 and TN3 could enter into the VBNC state with different incubation times, and could recover culturability by reversal of unfavourable factors and addition of resuscitation-promoting factor (Rpf), respectively. Furthermore, the gene expression variations in the VBNC response were clarified by Illumina high throughput RNA-sequencing. Genome-wide transcriptional analysis demonstrated that up-regulated genes in the VBNC cells of the strain TG13 related to protein modification, ATP accumulation and RNA polymerase, while all differentially expressed genes (DEGs) in the VBNC cells of the strain TN3 were down-regulated. However, the down-regulated genes in both the two strains mainly encoded NADH dehydrogenase subunit, catalase, oxidoreductase, which further verified that cold-induced loss of ability to defend oxidative stress may play an important role in induction of the VBNC state. This study further verified that the molecular mechanisms underlying the VBNC state varied with various bacterial species. Study on the VBNC state of non-pathogenic bacteria will provide new insights into the limitation of environmental micro-bioremediation and the cultivation of unculturable species. PMID:26808070

  7. Disseminated rhodococcus equi infection in HIV infection despite highly active antiretroviral therapy

    PubMed Central

    2011-01-01

    Background Rhodococcus equi (R.equi) is an acid fast, GRAM + coccobacillus, which is widespread in the soil and causes pulmonary and extrapulmonary infections in immunocompromised people. In the context of HIV infection, R.equi infection (rhodococcosis) is regarded as an opportunistic disease, and its outcome is influenced by highly active antiretroviral therapy (HAART). Case presentation We report two cases of HIV-related rhodococcosis that disseminated despite suppressive HAART and anti-rhodococcal treatment; in both cases there was no immunological recovery, with CD4+ cells count below 200/μL. In the first case, pulmonary rhodococcosis presented 6 months after initiation of HAART, and was followed by an extracerebral intracranial and a cerebral rhodococcal abscess 1 and 8 months, respectively, after onset of pulmonary infection. The second case was characterized by a protracted course with spread of infection to various organs, including subcutaneous tissue, skin, colon and other intra-abdominal tissues, and central nervous system; the spread started 4 years after clinical resolution of a first pulmonary manifestation and progressed over a period of 2 years. Conclusions Our report highlights the importance of an effective immune recovery, despite fully suppressive HAART, along with anti-rhodococcal therapy, in order to clear rhodococcal infection. PMID:22168333

  8. Transformation of Rhodococcus fascians by high-voltage electroporation and development of R. fascians cloning vectors

    SciTech Connect

    Desomer, J.; Dhaese, P.; Montagu, M.V. )

    1990-09-01

    The analysis of the virulence determinants of phytopathogenic Rhodococcus fascians has been hampered by the lack of a system for introducing exogenous DNA. We investigated the possibility of genetic transformation of R. fascians by high-voltage electroporation of intact bacterial cells in the presence of plasmid DNA. Electrotransformation in R. fascians D188 resulted in transformation frequencies ranging from 10{sup 5}/{mu}g of DNA to 10{sup 7}/{mu}g of DNA, depending on the DNA concentration. The effects of different electrical parameters and composition of electroporation medium on transformation efficiency are present. By this transformation method, a cloning vector (pRF28) for R. fascians based on an indigenous 160-kilobase (chloramphenicol and cadmium resistance-encoding) plasmid pRF2 from strain NCPPB 1675 was developed. The origin of replication and the chloramphenicol resistance gene on pRF28 were used to construct cloning vectors that are capable of replication in R. fascians and Escherichia coli. The electroporation method presented was efficient enough to allow detection of the rare integration of replication-deficient pRF28 derivatives in the R.fascians D188 genome via either homologous or illegitimate recombination.

  9. Mathematic Modeling for Optimum Conditions on Aflatoxin B1 Degradation by the Aerobic Bacterium Rhodococcus erythropolis

    PubMed Central

    Kong, Qing; Zhai, Cuiping; Guan, Bin; Li, Chunjuan; Shan, Shihua; Yu, Jiujiang

    2012-01-01

    Response surface methodology was employed to optimize the degradation conditions of AFB1 by Rhodococcus erythropolis in liquid culture. The most important factors that influence the degradation, as identified by a two-level Plackett-Burman design with six variables, were temperature, pH, liquid volume, inoculum size, agitation speed and incubation time. Central composite design (CCD) and response surface analysis were used to further investigate the interactions between these variables and to optimize the degradation efficiency of R. erythropolis based on a second-order model. The results demonstrated that the optimal parameters were: temperature, 23.2 °C; pH, 7.17; liquid volume, 24.6 mL in 100-mL flask; inoculum size, 10%; agitation speed, 180 rpm; and incubation time, 81.9 h. Under these conditions, the degradation efficiency of R. erythropolis could reach 95.8% in liquid culture, which was increased by about three times as compared to non-optimized conditions. The result by mathematic modeling has great potential for aflatoxin removal in industrial fermentation such as in food processing and ethanol production. PMID:23202311

  10. Maturation of Rhodococcus equi-containing vacuoles is arrested after completion of the early endosome stage.

    PubMed

    Fernandez-Mora, Eugenia; Polidori, Marco; Lührmann, Anja; Schaible, Ulrich E; Haas, Albert

    2005-08-01

    Rhodococcus equi is a facultative intracellular bacterium that can cause bronchopneumonia in foals and AIDS patients. Here, we have analyzed R. equi-containing vacuoles (RCVs) in murine macrophages by confocal laser scanning microscopy, by transmission electron microscopy and by immunochemistry upon purification. We show that RCVs progress normally through the early stages of phagosome maturation acquiring PI3P, early endosome antigen-1, and Rab5, and loosing all or much of them within minutes. Although mature RCVs possess the normally late endocytic markers, lysosome-associated membrane proteins, lysobisphosphatidic acid and Rab7, they lack other hallmark features of late endocytic organelles such as possession of cathepsin D, acid beta-glucuronidase, proton-pumping ATPase and the ability to fuse with prelabeled lysosomes. Bacterial strains possessing a virulence-associated plasmid maintain a nonacidified compartment for 48 h, whereas isogenic strains lacking such plasmids acidify progressively. In summary, RCVs represent a novel phagosome maturation stage positioned after completion of the early endosome stage and before reaching a fully mature late endosome compartment. In addition, vacuole biogenesis can be influenced by bacterial plasmids. PMID:15998320

  11. Comparative transcriptomics elucidates adaptive phenol tolerance and utilization in lipid-accumulating Rhodococcus opacus PD630.

    PubMed

    Yoneda, Aki; Henson, William R; Goldner, Nicholas K; Park, Kun Joo; Forsberg, Kevin J; Kim, Soo Ji; Pesesky, Mitchell W; Foston, Marcus; Dantas, Gautam; Moon, Tae Seok

    2016-03-18

    Lignin-derived (e.g. phenolic) compounds can compromise the bioconversion of lignocellulosic biomass to fuels and chemicals due to their toxicity and recalcitrance. The lipid-accumulating bacterium Rhodococcus opacus PD630 has recently emerged as a promising microbial host for lignocellulose conversion to value-added products due to its natural ability to tolerate and utilize phenolics. To gain a better understanding of its phenolic tolerance and utilization mechanisms, we adaptively evolved R. opacus over 40 passages using phenol as its sole carbon source (up to 373% growth improvement over wild-type), and extensively characterized two strains from passages 33 and 40. The two adapted strains showed higher phenol consumption rates (∼20 mg/l/h) and ∼2-fold higher lipid production from phenol than the wild-type strain. Whole-genome sequencing and comparative transcriptomics identified highly-upregulated degradation pathways and putative transporters for phenol in both adapted strains, highlighting the important linkage between mechanisms of regulated phenol uptake, utilization, and evolved tolerance. Our study shows that the R. opacus mutants are likely to use their transporters to import phenol rather than export them, suggesting a new aromatic tolerance mechanism. The identified tolerance genes and pathways are promising candidates for future metabolic engineering in R. opacus for improved lignin conversion to lipid-based products. PMID:26837573

  12. Response of Rhodococcus erythropolis strain IBBPo1 to toxic organic solvents

    PubMed Central

    Stancu, Mihaela Marilena

    2015-01-01

    Abstract Recently, there has been a lot of interest in the utilization of rhodococci in the bioremediation of petroleum contaminated environments. This study investigates the response of Rhodococcus erythropolis IBBPo1 cells to 1% organic solvents (alkanes, aromatics). A combination of microbiology, biochemical, and molecular approaches were used to examine cell adaptation mechanisms likely to be pursued by this strain after 1% organic solvent exposure. R. erythropolis IBBPo1 was found to utilize 1% alkanes (cyclohexane, n-hexane, n-decane) and aromatics (toluene, styrene, ethylbenzene) as the sole carbon source. Modifications in cell viability, cell morphology, membrane permeability, lipid profile, carotenoid pigments profile and 16S rRNA gene were revealed in R. erythropolis IBBPo1 cells grown 1 and 24 h on minimal medium in the presence of 1% alkanes (cyclohexane, n-hexane, n-decane) and aromatics (toluene, styrene, ethylbenzene). Due to its environmental origin and its metabolic potential, R. erythropolis IBBPo1 is an excellent candidate for the bioremediation of soils contaminated with crude oils and other toxic compounds. Moreover, the carotenoid pigments produced by this nonpathogenic Gram-positive bacterium have a variety of other potential applications. PMID:26691458

  13. Degradation of chloronitrobenzenes by a coculture of Pseudomonas putida and a Rhodococcus sp.

    SciTech Connect

    Park, H.S.; Lim, S.J.; Chang, Y.K.; Kim, H.S.; Livingston, A.G.

    1999-03-01

    A single microorganism able to mineralize chloronitrobenzenes (CNBs) has not been reported, and degradation of CNBs of coculture of two microbial strains was attempted. Pseudomonas putida HS12 was first isolated by analogue enrichment culture using nitrobenzene (NB) as the substrate, and this strain was observed to possess a partial reductive pathway for the degradation of NB. From high-performance liquid chromatography-mass spectrometry and {sup 1}H nuclear magnetic resonance analyses, NB-grown cells of P. putida HS12 were found to convert 3- and 4-CNBs to the corresponding 5- and 4-chloro-2-hydroxyacetanilides, respectively, by partial reduction and subsequent acetylation. For the degradation of CNBs, Rhodococcus sp. strain HS51, which degrades 4- and 5-chloro-2-hydroxyacetanilides, was isolated and combined with P. putida HS12 to give a coculture. This coculture was confirmed to mineralize 3- and 4-CNBs in the presence of an additional carbon source. A degradation pathway for 3- and 4-CNBs by the two isolated strains was also proposed.

  14. Bioadsorption Behavior of Rhodococcus Opacus on the Surface of Calcium and Magnesium Minerals

    NASA Astrophysics Data System (ADS)

    Li, Hongxu; Zhang, Mingming; Li, Chao; Yang, Xie; Li, An; Zhang, Lifeng

    2015-02-01

    The surface properties of minerals can be influenced and changed by microbial activities when microorganisms adhere to the mineral surface. The change of mineral surface properties and thus mineral floatability can be used to separate gangues from valuable minerals. This study investigated the Rhodococcus opacus ( R. opacus) adsorption behavior on the surfaces of calcite, serpentine, and dolomite by bioadhesive test, contact angle measurements, Zeta potential, Fourier transform infrared spectroscopy (FTIR) spectra, and scanning electron microscopy (SEM). The results showed that R. opacus could be absorbed well onto the surfaces of calcite, serpentine, and dolomite in a few minutes, with adsorption rate up to 96%. The cell adsorption was dependent on the pH value and the most suitable pH is 7.2, whereas no significant influence of temperature on adsorption was found. Increasing pulp density could provide more adsorption sites to R. opacus cells and increase the adsorption rate consequently. The contact angle of three minerals decreased after R. opacus attached, which indicated that the dispersibility of the mineral surface was improved and in favor of being separated. Zeta potential measurements showed that the cell with the charge was opposite to that of minerals on a broad of pH value. The SEM images showed that R. opacus attached very tightly onto the mineral surface, with a large number of small mineral particles gathered around the cell. FTIR spectra showed the presence of polymer groups on the cell wall that could have given a net charge on the mineral surface.

  15. Identification, characterization and molecular analysis of the viable but nonculturable Rhodococcus biphenylivorans.

    PubMed

    Su, Xiaomei; Sun, Faqian; Wang, Yalin; Hashmi, Muhammad Zaffar; Guo, Li; Ding, Linxian; Shen, Chaofeng

    2015-01-01

    Numerous bacteria, including pollutant-degrading bacteria can enter the viable but nonculturable state (VBNC) when they encounter harsh environmental conditions. VBNC bacteria, as a vast majority of potent microbial resource can be of great significance in environmental rehabilitation. It is necessary to study the VBNC state of pollutant-degrading bacteria under various stress conditions. The aim of this study was to determine whether Rhodococcus biphenylivorans could enter the VBNC state under oligotrophic and low temperature conditions, and to examine the changes of morphology, enzymatic activity and gene expressions that might underline such state. The obtained results indicated that R. biphenylivorans TG9(T) could enter into the VBNC state and recover culturability under favorable environmental conditions. Results from Illumina high throughput RNA-sequencing revealed that the up-regulated genes related to ATP accumulation, protein modification, peptidoglycan biosynthesis and RNA polymerase were found in the VBNC cells, and the down-regulated genes mainly encoded hypothetical protein, membrane protein and NADH dehydrogenase subunit, which render VBNC cells more tolerant to survive under inhospitable conditions. This study provides new insights into prevention and control of the VBNC state of pollutant-degrading bacteria for their better capabilities in environmental rehabilitation. PMID:26687808

  16. Trehalose promotes Rhodococcus sp. strain YYL colonization in activated sludge under tetrahydrofuran (THF) stress

    PubMed Central

    He, Zhixing; Zhang, Kai; Wang, Haixia; Lv, Zhenmei

    2015-01-01

    Few studies have focused on the role of compatible solutes in changing the microbial community structure in bioaugmentation systems. In this study, we investigated the influence of trehalose as a biostimulant on the microbial community in tetrahydrofuran (THF)-treated wastewater bioaugmentation systems with Rhodococcus sp. YYL. Functional gene profile changes were used to study the variation in the microbial community. Soluble di-iron monooxygenases (SDIMO), particularly group-5 SDIMOs (i.e., tetrahydrofuran and propane monooxygenases), play a significant role in the initiation of the ring cleavage of tetrahydrofuran. Group-5 SDIMOs genes are enriched upon trehalose addition, and exogenous tetrahydrofuran monooxygenase (thmA) genes can successfully colonize bioaugmentation systems. Cytochrome P450 monooxygenases (P450s) have a significant role in catalyzing the region- and stereospecific oxidation of non-activated hydrocarbons, and THF was reported to inhibit P450s in the environment. The CYP153 family was chosen as a representative P450 to study the inhibitory effects of THF. The results demonstrated that CYP153 family genes exhibited significant changes upon THF treatment and that trehalose helped maintain a rich diversity and high abundance of CYP153 family genes. Biostimulation with trehalose could alleviate the negative effects of THF stress on microbial diversity in bioaugmentation systems. Our results indicated that trehalose as a compatible solute plays a significant role for environmental strains under extreme conditions. PMID:26029182

  17. Dynamic Metabolic and Transcriptional Profiling of Rhodococcus sp. Strain YYL during the Degradation of Tetrahydrofuran

    PubMed Central

    He, Zhixing; Yao, Yanlai

    2014-01-01

    Although tetrahydrofuran-degrading Rhodococcus sp. strain YYL possesses tetrahydrofuran (THF) degradation genes similar to those of other tetrahydrofuran-degrading bacteria, a much higher degradation efficiency has been observed in strain YYL. In this study, nuclear magnetic resonance (NMR)-based metabolomics analyses were performed to explore the metabolic profiling response of strain YYL to exposure to THF. Exposure to THF slightly influenced the metabolome of strain YYL when yeast extract was present in the medium. The metabolic profile of strain YYL over time was also investigated using THF as the sole carbon source to identify the metabolites associated with high-efficiency THF degradation. Lactate, alanine, glutarate, glutamate, glutamine, succinate, lysine, trehalose, trimethylamine-N-oxide (TMAO), NAD+, and CTP were significantly altered over time in strain YYL grown in 20 mM THF. Real-time quantitative PCR (RT-qPCR) revealed changes in the transcriptional expression levels of 15 genes involved in THF degradation, suggesting that strain YYL could accumulate several disturbances in osmoregulation (trehalose, glutamate, glutamine, etc.), with reduced glycolysis levels, an accelerated tricarboxylic acid cycle, and enhanced protein synthesis. The findings obtained through 1H NMR metabolomics analyses and the transcriptional expression of the corresponding genes are complementary for exploring the dynamic metabolic profile in organisms. PMID:24532074

  18. Development of a genetic transformation system for benzene-tolerant Rhodococcus opacus strains.

    PubMed

    Na, Kyung-Su; Nagayasu, Kan; Kuroda, Akio; Takiguchi, Noboru; Ikeda, Tsukasa; Ohtake, Hisao; Kato, Junichi

    2005-04-01

    Rhodococcus opacus B-4 and B-9 are tolerant to various organic solvents including benzene, toluene, ethylbenzene, xylenes and styrene, and are suitable bacterial hosts for the production of chemical products from hydrophobic substrates. A 4.4-kb endogenous plasmid (pKNR 01) was isolated from R. opacus B-4 and sequenced completely. Plasmid pKNR 01 encodes proteins that share similarity to replication proteins from the enteric bacterial and actinomycete theta-replication plasmids. A 7.4-kb chimeric plasmid, designated pKNR 01.1, was constructed by fusing XhoI-digested pKNR 01 and Escherichia coli vector pSTV 28. Plasmid pKNR 01.1 had the ability to replicate in B-4 and B-9. A protocol for transformation of B-9 by electroporation was optimized employing pKNR 01.1. Frequencies of 4.1 x 10(5) transformants per mug of plasmid DNA were obtained for B-9 cells, whereas B-4 harboring naturally occurring pKNR 01 was transformed at lower frequencies (approximately 1 x 10(4) transformants per mug of plasmid DNA). Deletion analysis of pKNR 01.1 showed that the 1.9-kb SphI-XhoI region containing the repA and rep B genes and the 0.6-kb region upstream of repA was essential for plasmid maintenance in R. opacus strains. PMID:16233810

  19. Directed Evolution and Mutant Characterization of Nitrilase from Rhodococcus rhodochrous tg1-A6.

    PubMed

    Luo, Hui; Ma, Jinwei; Chang, Yanhong; Yu, Huimin; Shen, Zhongyao

    2016-04-01

    In this paper, a molecularly directed evolution-based approach was applied to modify the nitrilase from Rhodococcus rhodochrous tg1-A6 for improving properties in catalyzing nitriles. In the process of error-prone polymerase chain reaction (PCR) with the wild-type nitrilase gene acting as the template, a library of the randomly mutated nitrilase gene was constructed. Since the pH value of catalyzing solution decreased when glycolonitrile was used as the substrate of nitrilase, a high-throughput strategy based on the color change of a pH-sensitive indicator was established for rapid screening of the mutated nitrilase. After three rounds of random mutation and screening about 5000 clones, a variant (Mut3) with 5.3-fold activity of the wild-type counterpart was obtained. Five amino acid substitutions (D27E, N97K, L246F, D108E, and S111R) were found in the variant Mut3. The properties of three mutated enzymes obtained in the three-round mutation were investigated. In the conversion of glycolonitrile, the variant (Mut2) accumulated the highest concentration of glycolic acid at 10.6 g l(-1), a much higher value than the wild type (3.2 g l(-1)). PMID:26712248

  20. Induction of Viable but Nonculturable State in Rhodococcus and Transcriptome Analysis Using RNA-seq

    PubMed Central

    Su, Xiaomei; Guo, Li; Ding, Linxian; Qu, Kun; Shen, Chaofeng

    2016-01-01

    Viable but nonculturable (VBNC) bacteria, which maintain the viability with loss of culturability, universally exist in contaminated and non-contaminated environments. In this study, two strains, Rhodococcus sp. TG13 and TN3, which were isolated from PCB-contaminated sediment and non-contaminated sediment respectively, were investigated under low temperature and oligotrophic conditions. The results indicated that the two strains TG13 and TN3 could enter into the VBNC state with different incubation times, and could recover culturability by reversal of unfavourable factors and addition of resuscitation-promoting factor (Rpf), respectively. Furthermore, the gene expression variations in the VBNC response were clarified by Illumina high throughput RNA-sequencing. Genome-wide transcriptional analysis demonstrated that up-regulated genes in the VBNC cells of the strain TG13 related to protein modification, ATP accumulation and RNA polymerase, while all differentially expressed genes (DEGs) in the VBNC cells of the strain TN3 were down-regulated. However, the down-regulated genes in both the two strains mainly encoded NADH dehydrogenase subunit, catalase, oxidoreductase, which further verified that cold-induced loss of ability to defend oxidative stress may play an important role in induction of the VBNC state. This study further verified that the molecular mechanisms underlying the VBNC state varied with various bacterial species. Study on the VBNC state of non-pathogenic bacteria will provide new insights into the limitation of environmental micro-bioremediation and the cultivation of unculturable species. PMID:26808070

  1. Bacterial O-methylation of halogen-substituted phenols. [Rhodococcus; Acinetobacter

    SciTech Connect

    Allard, A.S.; Remberger, M.; Neilson, A.H.

    1987-04-01

    Two strains of bacteria capable of carrying out the O-methylation of phenolic compounds, one from the gram-positive genus Rhodococcus and one from the gram-negative genus Acinetobacter, were used to examine the O-methylation of phenols carrying fluoro-, chloro-, and bromo-substituents. Zero-order rates of O-methylation were calculated from data for the chloro- and bromophenols; there was no simple relationship between the rate of reaction and the structure of the substrates, and significant differences were observed in the responses of the two test organisms. For the gram-negative strain, the pattern of substitution was as important as the number of substituents. Hexachlorophene was resistant to O-methylation by both strains, and tetrabromobisphenol-A was O-methylated only by the gram-positive strain. It is suggested that in the natural environment, bacterial O-methylation of phenols carrying electron-attracting substituents might be a significant alternative to biodegradation.

  2. Nitric Oxide-Mediated Intracellular Growth Restriction of Pathogenic Rhodococcus equi Can Be Prevented by Iron▿

    PubMed Central

    von Bargen, Kristine; Wohlmann, Jens; Taylor, Gregory Alan; Utermöhlen, Olaf; Haas, Albert

    2011-01-01

    Rhodococcus equi is an intracellular pathogen which causes pneumonia in young horses and in immunocompromised humans. R. equi arrests phagosome maturation in macrophages at a prephagolysosome stage and grows inside a privileged compartment. Here, we show that, in murine macrophages activated with gamma interferon and lipopolysaccharide, R. equi does not multiply but stays viable for at least 24 h. Whereas infection control of other intracellular pathogens by activated macrophages is executed by enhanced phagosome acidification or phagolysosome formation, by autophagy or by the interferon-inducible GTPase Irgm1, none of these mechanisms seems to control R. equi infection. Growth control by macrophage activation is fully mimicked by treatment of resting macrophages with nitric oxide donors, and inhibition of bacterial multiplication by either activation or nitric oxide donors is annihilated by cotreatment of infected macrophages with ferrous sulfate. Transcriptional analysis of the R. equi iron-regulated gene iupT demonstrates that intracellular R. equi encounters iron stress in activated, but not in resting, macrophages and that this stress is relieved by extracellular addition of ferrous sulfate. Our results suggest that nitric oxide is central to the restriction of bacterial access to iron in activated macrophages. PMID:21383050

  3. Mouse lung infection model to assess Rhodococcus equi virulence and vaccine protection.

    PubMed

    González-Iglesias, Patricia; Scortti, Mariela; MacArthur, Iain; Hapeshi, Alexia; Rodriguez, Héctor; Prescott, John F; Vazquez-Boland, José A

    2014-08-01

    The pathogenic actinomycete Rhodococcus equi causes severe purulent lung infections in foals and immunocompromised people. Although relatively unsusceptible to R. equi, mice are widely used for in vivo studies with this pathogen. The most commonly employed mouse model is based on systemic (intravenous) infection and determination of R. equi burdens in spleen and liver. Here, we investigated the murine lung for experimental infection studies with R. equi. Using a 10(7)CFU intranasal challenge in BALB/c mice, virulent R. equi consistently survived in quantifiable numbers up to 10 days in the lungs whereas virulence-deficient R. equi bacteria were rapidly cleared. An internally controlled virulence assay was developed in which the test R. equi strains are co-inoculated and monitored in the same mouse. Isogenic R. equi bacteria lacking either the plasmid vapA gene or the entire virulence plasmid were compared using this competitive assay. Both strains showed no significant differences in in vivo fitness in the lung, indicating that the single loss of the virulence factor VapA was sufficient to account for the full attenuation seen in the absence of the virulence plasmid. To test the adequacy of the lung infection model for monitoring R. equi vaccine efficacy, BALB/c mice were immunized with live R. equi and challenged intranasally. Vaccination conferred protection against acute pulmonary challenge with virulent R. equi. Our data indicate that the murine lung infection model provides a useful tool for both R. equi virulence and vaccine studies. PMID:24852140

  4. The sensor kinase MprB is required for Rhodococcus equi virulence.

    PubMed

    MacArthur, Iain; Parreira, Valeria R; Lepp, Dion; Mutharia, Lucy M; Vazquez-Boland, José A; Prescott, John F

    2011-01-10

    Rhodococcus equi is a soil bacterium and, like Mycobacterium tuberculosis, a member of the mycolata. Through possession of a virulence plasmid, it has the ability to infect the alveolar macrophages of foals, resulting in pyogranulomatous bronchopneumonia. The virulence plasmid has an orphan two-component system (TCS) regulatory gene, orf8, mutation of which completely attenuates virulence. This study attempted to find the cognate sensor kinase (SK) of orf8. Annotation of the R. equi strain 103 genome identified 23 TCSs encoded on the chromosome, which were used in a DNA microarray to compare TCS gene transcription in murine macrophage-like cells to growth in vitro. This identified six SKs as significantly up-regulated during growth in macrophages. Mutants of these SKs were constructed and their ability to persist in macrophages was determined with one SK, MprB, found to be required for intracellular survival. The attenuation of the mprB- mutant, and its complementation, was confirmed in a mouse virulence assay. In silico analysis of the R. equi genome sequence identified an MprA binding box motif homologous to that of M. tuberculosis, on mprA, pepD, sigB and sigE. The results of this study also show that R. equi responds to the macrophage environment differently from M. tuberculosis. MprB is the first SK identified as required for R. equi virulence and intracellular survival. PMID:20637548

  5. Mining the genome of Rhodococcus fascians, a plant growth-promoting bacterium gone astray.

    PubMed

    Francis, Isolde M; Stes, Elisabeth; Zhang, Yucheng; Rangel, Diana; Audenaert, Kris; Vereecke, Danny

    2016-09-25

    Rhodococcus fascians is a phytopathogenic Gram-positive Actinomycete with a very broad host range encompassing especially dicotyledonous herbaceous perennials, but also some monocots, such as the Liliaceae and, recently, the woody crop pistachio. The pathogenicity of R. fascians strain D188 is known to be encoded by the linear plasmid pFiD188 and to be dictated by its capacity to produce a mixture of cytokinins. Here, we show that D188-5, the nonpathogenic plasmid-free derivative of the wild-type strain D188 actually has a plant growth-promoting effect. With the availability of the genome sequence of R. fascians, the chromosome of strain D188 was mined for putative plant growth-promoting functions and the functionality of some of these activities was tested. This analysis together with previous results suggests that the plant growth-promoting activity of R. fascians is due to production of plant growth modulators, such as auxin and cytokinin, combined with degradation of ethylene through 1-amino-cyclopropane-1-carboxylic acid deaminase. Moreover, R. fascians has several functions that could contribute to efficient colonization and competitiveness, but there is little evidence for a strong impact on plant nutrition. Possibly, the plant growth promotion encoded by the D188 chromosome is imperative for the epiphytic phase of the life cycle of R. fascians and prepares the plant to host the bacteria, thus ensuring proper continuation into the pathogenic phase. PMID:26877150

  6. Comparative transcriptomics elucidates adaptive phenol tolerance and utilization in lipid-accumulating Rhodococcus opacus PD630

    PubMed Central

    Yoneda, Aki; Henson, William R.; Goldner, Nicholas K.; Park, Kun Joo; Forsberg, Kevin J.; Kim, Soo Ji; Pesesky, Mitchell W.; Foston, Marcus; Dantas, Gautam; Moon, Tae Seok

    2016-01-01

    Lignin-derived (e.g. phenolic) compounds can compromise the bioconversion of lignocellulosic biomass to fuels and chemicals due to their toxicity and recalcitrance. The lipid-accumulating bacterium Rhodococcus opacus PD630 has recently emerged as a promising microbial host for lignocellulose conversion to value-added products due to its natural ability to tolerate and utilize phenolics. To gain a better understanding of its phenolic tolerance and utilization mechanisms, we adaptively evolved R. opacus over 40 passages using phenol as its sole carbon source (up to 373% growth improvement over wild-type), and extensively characterized two strains from passages 33 and 40. The two adapted strains showed higher phenol consumption rates (∼20 mg/l/h) and ∼2-fold higher lipid production from phenol than the wild-type strain. Whole-genome sequencing and comparative transcriptomics identified highly-upregulated degradation pathways and putative transporters for phenol in both adapted strains, highlighting the important linkage between mechanisms of regulated phenol uptake, utilization, and evolved tolerance. Our study shows that the R. opacus mutants are likely to use their transporters to import phenol rather than export them, suggesting a new aromatic tolerance mechanism. The identified tolerance genes and pathways are promising candidates for future metabolic engineering in R. opacus for improved lignin conversion to lipid-based products. PMID:26837573

  7. Immunogenicity of synthetic Rhodococcus equi virulence-associated protein peptides in neonate foals.

    PubMed

    Cauchard, Julien; Taouji, Saïd; Sevin, Corinne; Duquesne, Fabien; Bernabé, Magali; Laugier, Claire; Ballet, Jean Jacques

    2006-10-01

    Rhodococcus equi infection is considered the most common cause of pneumonia in foals less than 6 months of age. Immunization of foals and/or mares may become a procedure of choice for prevention. The present work documents the antibody response of neonate foals to R. equi virulence-associated protein (Vap) vaccine candidate peptides. A mixture of 4 R. equi (ATCC 33701) Vap peptides was selected based on their hydrophilicity and recognition by naturally acquired IgG antibodies from 13 adult horses and 33 neonate foals from France and Japan. They were combined with a water-based nanoparticular adjuvant to promote a protective immune response including both Th1 cytokine pattern and antibody response. A single intramuscular injection resulted in an IgG antibody response 30 days later, although inconsistently. In responding animals, no bias in IgG subclass distribution was observed, and antibody response was associated with enhanced serum opsonic activity. In conclusion, data indicate that synthetic Vap peptides combined with nanoparticular adjuvant were immunogenic and resulted in a significant increase in IgG antibodies against the corresponding virulent R. equi strain in a majority of foals. PMID:16782401

  8. Rhodococcus equi venous catheter infection: a case report and review of the literature

    PubMed Central

    2011-01-01

    Introduction Rhodococcus equi is an animal pathogen that was initially isolated from horses and is being increasingly reported as a cause of infection in humans with impaired cellular immunity. However, this pathogen is underestimated as a challenging antagonist and is frequently considered to be a mere contaminant despite the potential for life-threatening infections. Most case reports have occurred in immunocompromised patients who have received organ transplants (for example kidney, heart, bone marrow) or those with human immunodeficiency virus infection. Infections often manifest as pulmonary involvement or soft tissue abscesses. Bacteremia related to R. equi infections of tunneled central venous catheters has rarely been described. Case presentation We report the case of a 63-year-old non-transplant recipient, non-HIV infected Caucasian woman with endometrial carcinoma who developed recurrent bloodstream infections and septic shock due to R. equi and ultimately required the removal of her port catheter, a subcutaneous implantable central venous catheter. We also review the medical literature related to human infections with R. equi. Conclusion R. equi should be considered a serious pathogen, not a contaminant, particularly in an immunocompromised patient who presents with a central venous catheter-related bloodstream infection. Counseling patients with central venous catheters who participate in activities involving exposure to domesticated animals is recommended. PMID:21827681

  9. Modulation of Cytokine Response of Pneumonic Foals by Virulent Rhodococcus equi

    PubMed Central

    Giguère, Steeve; Wilkie, Bruce N.; Prescott, John F.

    1999-01-01

    The ability of Rhodococcus equi to induce pneumonia in foals depends on the presence of an 85- to 90-kb plasmid. In this study, we evaluated whether plasmid-encoded products mediate virulence by modulating the cytokine response of foals. Foals infected intrabronchially with a virulence plasmid-containing strain of R. equi had similar gamma interferon (IFN-γ) and interleukin-12 (IL-12) p35 but significantly higher IL-1β, IL-10, IL-12 p40, and tumor necrosis factor alpha (TNF-α) mRNA expression in lung tissue compared to foals infected with the plasmid-cured derivative. IFN-γ mRNA expression levels in CD4+ T lymphocytes isolated from bronchial lymph nodes (BLN) were similar for the two groups of R. equi-infected foals on day 3 postinfection. However, on day 14, in association with pneumonia and marked multiplication of virulent R. equi but with complete clearance of the plasmid-cured derivative, IFN-γ mRNA expression in BLN CD4+ T lymphocytes was significantly (P < 0.001) higher in foals infected with the plasmid-cured derivative. These results suggests an immunomodulating role for R. equi virulence plasmid-encoded products in downregulating IFN-γ mRNA expression by CD4+ T lymphocytes. PMID:10496876

  10. Early development of cytotoxic T lymphocytes in neonatal foals following oral inoculation with Rhodococcus equi

    PubMed Central

    Harris, Seth P.; Hines, Melissa T.; Mealey, Robert H.; Alperin, Debra C.; Hines, Stephen A.

    2012-01-01

    Rhodococcus equi is an important respiratory pathogen of young foals for which a vaccine has long been sought. Two major impediments to effective vaccination are the functionally immature type I immune responses of neonatal foals and early exposure to the bacterium via the environment. Despite these obstacles, it appears that under specific circumstances foals can develop a protective immune response. In this study we investigated the protective mechanisms behind oral inoculation of foals with virulent R. equi bacteria. Two foals receiving an oral inoculum demonstrated accelerated development of R. equi specific cytotoxic T lymphocytes (CTL) as evidenced by significant lysis of R. equi infected, ELA-A mismatched cells at 3 weeks of age. As in a previous study, CTL were not detected until 5–6 weeks of age in two control foals. At each time point the ability of foal peripheral blood mononuclear cells (PBMC) to produce IFN-γ following stimulation with live R. equi or extracted cell wall lipids was similar to that of an adult horse control and between foals, regardless of treatment. These results provide a potential mechanism of protection which has previously been shown to occur following oral inoculation, and suggest that the early detection of CTL may be a useful marker for induction of protective immunity. PMID:21481947

  11. Eternal youth, the fate of developing Arabidopsis leaves upon Rhodococcus fascians infection.

    PubMed

    Depuydt, Stephen; De Veylder, Lieven; Holsters, Marcelle; Vereecke, Danny

    2009-03-01

    The phytopathogenic actinomycete Rhodococcus fascians induces neoplastic shooty outgrowths on infected hosts. Upon R. fascians infection of Arabidopsis (Arabidopsis thaliana), leaves are formed with small narrow lamina and serrated margins. These symptomatic leaves exhibit reduced tissue differentiation, display more but smaller cells that do not endoreduplicate, and accumulate in the G1 phase of the cell cycle. Together, these features imply that leaf growth occurs primarily through mitotic cell division and not via cell expansion. Molecular analysis revealed that cell cycle gene expression is activated continuously throughout symptomatic leaf development, ensuring persistent mitotic cycling and inhibition of cell cycle exit. The transition at the two major cell cycle checkpoints is stimulated as a direct consequence of the R. fascians signals. The extremely reduced phenotypical response of a cyclind3;1-3 triple knockout mutant indicates that the D-type cyclin/retinoblastoma/E2F transcription factor pathway, as a major mediator of cell growth and cell cycle progression, plays a key role in symptom development and is instrumental for the sustained G1-to-S and G2-to-M transitions during symptomatic leaf growth. PMID:19118126

  12. Engineering of an L-arabinose metabolic pathway in Rhodococcus jostii RHA1 for biofuel production.

    PubMed

    Xiong, Xiaochao; Wang, Xi; Chen, Shulin

    2016-07-01

    The oleaginous bacterium, Rhodococcus jostii RHA1 has attracted considerable attention due to its capability to accumulate significant levels of triacylglycerol as renewable hydrocarbon. To enable the strain to utilize arabinose derived from lignocellulosic biomass, the metabolic pathway of L-arabinose utilization was introduced into R. jostii RHA1 by heterogenous expression of the operon, araBAD from Escherichia coli. The results showed that recombinant bearing araBAD could grow on L-arabinose as the sole carbon source, and additional expression of araFGH encoding the arabinose transporter from E. coli could improve the cell biomass yield from high contents of arabinose. We further increased the content of lipid produced from arabinose in the recombinants from 47.9 to 56.8 % of the cell dry weight (CDW) by overexpression of a gene, atf1 encoding a diglyceride acyltransferase from R. opacus PD630. This work demonstrated the feasibility of producing lipid from arabinose by genetic modification of the rhodococci strain. PMID:27143134

  13. Pyrolysis oil-based lipid production as biodiesel feedstock by Rhodococcus opacus.

    PubMed

    Wei, Zhen; Zeng, Guangming; Kosa, Matyas; Huang, Danlian; Ragauskas, Arthur J

    2015-01-01

    Light oil from pyrolysis, which accounts for ∼10 % carbon yield of the starting biomass, is a complex aqueous product that is difficult to utilize and usually discarded. This work presents the feasibility of light oil as a sole carbon source to support the growth of Rhodococcus opacus (R. opacus) that in turn accumulate triacylglycerols as biodiesel feedstock. Two types of bacteria (R. opacus PD630 and DSM 1069) were selected in this study. Research results showed that after short adaption periods both strains can grow well on this complex carbon source, as proved by the consumption of oligomers and monomers in light oil. Lipid content by R. opacus PD630 and DSM 1069 was observed up to 25.8 % and 22.0 % of cell dry weight, respectively. Palmitic and stearic acids were found to be the predominant fatty acids in these bacterial cells. In addition, the light oil-based lipid production can be enhanced by reducing the pH value from 7 to 4, especially in case of DSM 1069. PMID:25377250

  14. Comparative transcriptomics elucidates adaptive phenol tolerance and utilization in lipid-accumulating Rhodococcus opacus PD630

    DOE PAGESBeta

    Yoneda, Aki; Henson, William R.; Goldner, Nicholas K.; Park, Kun Joo; Forsberg, Kevin J.; Kim, Soo Ji; Pesesky, Mitchell W.; Foston, Marcus; Dantas, Gautam; Moon, Tae Seok

    2016-02-02

    Lignin-derived (e.g. phenolic) compounds can compromise the bioconversion of lignocellulosic biomass to fuels and chemicals due to their toxicity and recalcitrance. The lipid-accumulating bacterium Rhodococcus opacus PD630 has recently emerged as a promising microbial host for lignocellulose conversion to value-added products due to its natural ability to tolerate and utilize phenolics. To gain a better understanding of its phenolic tolerance and utilization mechanisms, we adaptively evolved R. opacus over 40 passages using phenol as its sole carbon source (up to 373% growth improvement over wild-type), and extensively characterized two strains from passages 33 and 40. The two adapted strains showedmore » higher phenol consumption rates (~20 mg/l/h) and ~2-fold higher lipid production from phenol than the wild-type strain.Whole-genome sequencing and comparative transcriptomics identified highly-upregulated degradation pathways and putative transporters for phenol in both adapted strains, highlighting the important linkage between mechanisms of regulated phenol uptake, utilization, and evolved tolerance. Our study shows that the R. opacus mutants are likely to use their transporters to import phenol rather than export them, suggesting a new aromatic tolerance mechanism. The identified tolerance genes and pathways are promising candidates for future metabolic engineering in R. opacus for improved lignin conversion to lipid-based products.« less

  15. Abortion in a thoroughbred mare associated with an infection with avirulent Rhodococcus equi.

    PubMed

    Nakamura, Y; Nishi, H; Katayama, Y; Niwa, H; Matsumura, T; Anzai, T; Ohtsu, Y; Tsukano, K; Shimizu, N; Takai, S

    2007-09-01

    An eight-year-old thoroughbred mare with no previous history of illness aborted a fetus at 196 days of gestation, and its internal tissues were examined immunohistologically and bacteriologically. The placenta was not examined, but specimens of the intrauterine fluids and the dam's faeces were collected four days after the abortion and examined bacteriologically. No significant histological lesions were found in the fetus but the amnion and the umbilical cord were oedematous and had petechial haemorrhages. Rhodococcus equi was isolated in pure culture from the lung, heart and stomach contents of the fetus and from an intrauterine specimen and faeces of the dam. The anti-R equi antibody titre of the mare was high after the abortion. The diagnosis was confirmed in the lung of the fetus by immunohistochemical staining with R equi-specific antibodies. Isolates from the fetus and mare were identified as avirulent R equi by pcr and the mouse pathogenicity test. The avirulent isolates were characterised by pulsed-field gel electrophoresis, which yielded only one VspI profile in all the isolates from the fetus and its dam. PMID:17827474

  16. Septic pleuritis and abdominal abscess formation caused by Rhodococcus equi in a foal.

    PubMed

    Valdes, Alejandro; Johnson, Jill R

    2005-09-15

    A 3-month-old female Arabian horse was evaluated because of fever, respiratory distress, lethargy, and decreased appetite of 5 days' duration. Pleural effusion was diagnosed on the basis of ultrasonographic and radiographic examinations. Cytologic examination of pleural fluid collected via thoracocentesis revealed septic inflammation; bacteriologic culture of a sample of that fluid yielded Rhodococcus equi. A large intra-abdominal mass adjacent to the body wall was identified ultrasonographically. A specimen of the mass was collected via aspiration; the specimen was identified cytologically as purulent exudate that contained large numbers of rod-shaped bacteria, which confirmed abdominal abscess formation. Bacteriologic culture of a sample of the exudate also yielded R. equi. The foal was treated with azithromycin (10 mg/kg [4.5 mg/lb], PO, q 24 h for 5 days then q 48 h) and rifampin (5 mg/kg [2.3 mg/lb], PO, q 12 h) for 8 weeks and metronidazole (15 mg/kg [6.8 mg/lb], PO, q 8 h) for 3 weeks. Clinically, the foal responded to antimicrobial treatment within 2 weeks. At 8 weeks after the initial evaluation, ultrasonographic examination of the foal revealed resolution of the pleural effusion and abdominal abscess. In foals, R. equi infection typically results in pyogranulomatous pneumonia, and pleural effusion is an uncommon clinical sign. The combination of azithromycin and rifampin appears to be an effective treatment for R. equi infection in foals. PMID:16190597

  17. Benzoate degradation by Rhodococcus opacus 1CP after dormancy: Characterization of dioxygenases involved in the process.

    PubMed

    Solyanikova, Inna P; Emelyanova, Elena V; Borzova, Oksana V; Golovleva, Ludmila A

    2016-01-01

    The process of benzoate degradation by strain Rhodococcus opacus 1CP after a five-year dormancy was investigated and its peculiarities were revealed. The strain was shown to be capable of growth on benzoate at a concentration of up to 10 g L(-1). The substrate specificity of benzoate dioxygenase (BDO) during the culture growth on a medium with a low (200-250 mg L(-1)) and high (4 g L(-1)) concentration of benzoate was assessed. BDO of R. opacus 1CP was shown to be an extremely narrow specificity enzyme. Out of 31 substituted benzoates, only with one, 3-chlorobenzoate, its activity was higher than 9% of that of benzoate. Two dioxygenases, catechol 1,2-dioxygenase (Cat 1,2-DO) and protocatechuate 3,4-dioxygenase (PCA 3,4-DO), were identified in a cell-free extract, purified and characterized. The substrate specificity of Cat 1,2-DO isolated from cells of strain 1CP after the dormancy was found to differ significantly from that of Cat 1,2-DO isolated earlier from cells of this strain grown on benzoate. By its substrate specificity, the described Cat 1,2-DO was close to the Cat 1,2-DO from strain 1CP grown on 4-methylbenzoate. Neither activity nor inhibition by protocatechuate was observed during the reaction of Cat 1,2-DO with catechol, and catechol had no inhibitory effect on the reaction of PCA 3,4-DO with protocatechuate. PMID:26669259

  18. Metabolic responses of Rhodococcus erythropolis PR4 grown on diesel oil and various hydrocarbons.

    PubMed

    Laczi, Krisztián; Kis, Ágnes; Horváth, Balázs; Maróti, Gergely; Hegedüs, Botond; Perei, Katalin; Rákhely, Gábor

    2015-11-01

    Rhodococcus erythropolis PR4 is able to degrade diesel oil, normal-, iso- and cycloparaffins and aromatic compounds. The complete DNA content of the strain was previously sequenced and numerous oxygenase genes were identified. In order to identify the key elements participating in biodegradation of various hydrocarbons, we performed a comparative whole transcriptome analysis of cells grown on hexadecane, diesel oil and acetate. The transcriptomic data for the most prominent genes were validated by RT-qPCR. The expression of two genes coding for alkane-1-monooxygenase enzymes was highly upregulated in the presence of hydrocarbon substrates. The transcription of eight phylogenetically diverse cytochrome P450 (cyp) genes was upregulated in the presence of diesel oil. The transcript levels of various oxygenase genes were determined in cells grown in an artificial mixture, containing hexadecane, cycloparaffin and aromatic compounds and six cyp genes were induced by this hydrocarbon mixture. Five of them were not upregulated by linear and branched hydrocarbons. The expression of fatty acid synthase I genes was downregulated by hydrocarbon substrates, indicating the utilization of external alkanes for fatty acid synthesis. Moreover, the transcription of genes involved in siderophore synthesis, iron transport and exopolysaccharide biosynthesis was also upregulated, indicating their important role in hydrocarbon metabolism. Based on the results, complex metabolic response profiles were established for cells grown on various hydrocarbons. Our results represent a functional annotation of a rhodococcal genome, provide deeper insight into molecular events in diesel/hydrocarbon utilization and suggest novel target genes for environmental monitoring projects. PMID:26346267

  19. Colonization, biofilm formation and biodegradation of polyethylene by a strain of Rhodococcus ruber.

    PubMed

    Orr, I Gilan; Hadar, Y; Sivan, A

    2004-07-01

    A two-step enrichment procedure led to the isolation of a strain of Rhodococcus ruber (C208) that utilized polyethylene films as sole carbon source. In liquid culture, C208 formed a biofilm on the polyethylene surface and degraded up to 8% (gravimetrically) of the polyolefin within 30 days of incubation. The bacterial adhesion to hydrocarbon assay and the salt aggregation test both showed that the cell-surface hydrophobicity of C208 was higher than that of three other isolates which were obtained from the same consortium but were less efficient than C208 in the degradation of polyethylene. Mineral oil, but not nonionic surfactants, enhanced the colonization of polyethylene and increased biodegradation by about 50%. Fluorescein diacetate (FDA) hydrolysis and protein content analysis were used to test the viability and biomass density of the C208 biofilm on the polyethylene, respectively. Both FDA activity and protein content of the biofilm in a medium containing mineral oil peaked 48-72 h after inoculation and then decreased sharply. This finding apparently reflected rapid utilization of the mineral oil adhering to the polyethylene. The remaining biofilm population continued to proliferate moderately and presumably played a major role in biodegradation of the polyethylene. Fourier transform infrared spectra of UV-photooxidized polyethylene incubated with C208 indicated that biodegradation was initiated by utilization of the carbonyl residues formed in the photooxidized polyethylene. PMID:15221232

  20. Immunogenicity of an electron beam inactivated Rhodococcus equi vaccine in neonatal foals.

    PubMed

    Bordin, Angela I; Pillai, Suresh D; Brake, Courtney; Bagley, Kaytee B; Bourquin, Jessica R; Coleman, Michelle; Oliveira, Fabiano N; Mwangi, Waithaka; McMurray, David N; Love, Charles C; Felippe, Maria Julia B; Cohen, Noah D

    2014-01-01

    Rhodococcus equi is an important pathogen of foals that causes severe pneumonia. To date, there is no licensed vaccine effective against R. equi pneumonia of foals. The objectives of our study were to develop an electron beam (eBeam) inactivated vaccine against R. equi and evaluate its immunogenicity. A dose of eBeam irradiation that inactivated replication of R. equi while maintaining outer cell wall integrity was identified. Enteral administration of eBeam inactivated R. equi increased interferon-γ production by peripheral blood mononuclear cells in response to stimulation with virulent R. equi and generated naso-pharyngeal R. equi-specific IgA in newborn foals. Our results indicate that eBeam irradiated R. equi administered enterally produce cell-mediated and upper respiratory mucosal immune responses, in the face of passively transferred maternal antibodies, similar to those produced in response to enteral administration of live organisms (a strategy which previously has been documented to protect foals against intrabronchial infection with virulent R. equi). No evidence of adverse effects was noted among vaccinated foals. PMID:25153708

  1. Identification of novel extracellular protein for PCB/biphenyl metabolism in Rhodococcus jostii RHA1.

    PubMed

    Atago, Yuki; Shimodaira, Jun; Araki, Naoto; Bin Othman, Nor'azizi; Zakaria, Zuriati; Fukuda, Masao; Futami, Junichiro; Hara, Hirofumi

    2016-05-01

    Rhodococcus jostii RHA1 (RHA1) degrades polychlorinated biphenyl (PCB) via co-metabolism with biphenyl. To identify the novel open reading frames (ORFs) that contribute to PCB/biphenyl metabolism in RHA1, we compared chromatin immunoprecipitation chip and transcriptomic data. Six novel ORFs involved in PCB/biphenyl metabolism were identified. Gene deletion mutants of these 6 ORFs were made and were tested for their ability to grow on biphenyl. Interestingly, only the ro10225 deletion mutant showed deficient growth on biphenyl. Analysis of Ro10225 protein function showed that growth of the ro10225 deletion mutant on biphenyl was recovered when exogenous recombinant Ro10225 protein was added to the culture medium. Although Ro10225 protein has no putative secretion signal sequence, partially degraded Ro10225 protein was detected in conditioned medium from wild-type RHA1 grown on biphenyl. This Ro10225 fragment appeared to form a complex with another PCB/biphenyl oxidation enzyme. These results indicated that Ro10225 protein is essential for the formation of the PCB/biphenyl dioxygenase complex in RHA1. PMID:26828632

  2. Differential Degradation of Bicyclics with Aromatic and Alicyclic Rings by Rhodococcus sp. Strain DK17 ▿

    PubMed Central

    Kim, Dockyu; Yoo, Miyoun; Choi, Ki Young; Kang, Beom Sik; Kim, Tai Kyoung; Hong, Soon Gyu; Zylstra, Gerben J.; Kim, Eungbin

    2011-01-01

    The metabolically versatile Rhodococcus sp. strain DK17 is able to grow on tetralin and indan but cannot use their respective desaturated counterparts, 1,2-dihydronaphthalene and indene, as sole carbon and energy sources. Metabolite analyses by gas chromatography-mass spectrometry and nuclear magnetic resonance spectrometry clearly show that (i) the meta-cleavage dioxygenase mutant strain DK180 accumulates 5,6,7,8-tetrahydro-1,2-naphthalene diol, 1,2-indene diol, and 3,4-dihydro-naphthalene-1,2-diol from tetralin, indene, and 1,2-dihydronaphthalene, respectively, and (ii) when expressed in Escherichia coli, the DK17 o-xylene dioxygenase transforms tetralin, indene, and 1,2-dihydronaphthalene into tetralin cis-dihydrodiol, indan-1,2-diol, and cis-1,2-dihydroxy-1,2,3,4-tetrahydronaphthalene, respectively. Tetralin, which is activated by aromatic hydroxylation, is degraded successfully via the ring cleavage pathway to support growth of DK17. Indene and 1,2-dihydronaphthalene do not serve as growth substrates because DK17 hydroxylates them on the alicyclic ring and further metabolism results in a dead-end metabolite. This study reveals that aromatic hydroxylation is a prerequisite for proper degradation of bicyclics with aromatic and alicyclic rings by DK17 and confirms the unique ability of the DK17 o-xylene dioxygenase to perform distinct regioselective hydroxylations. PMID:21965391

  3. O-Methylation of Chlorinated para-Hydroquinones by Rhodococcus chlorophenolicus

    PubMed Central

    Häggblom, Max M.; Apajalahti, Juha H. A.; Salkinoja-Salonen, Mirja S.

    1988-01-01

    Rhodococcus chlorophenolicus PCP-I, a degrader of polychlorinated phenols, guaiacols (2-methoxyphenols), and syringols (2,6-dimethoxyphenols), was shown to O-methylate the degradation intermediate, a chlorinated para-hydroquinone, into 4-methoxyphenol. O-methylation was constitutively expressed, whereas the degradation of chlorophenols and chlorohydroquinones was inducible in R. chlorophenolicus. The O-methylating reaction required two hydroxyl groups in positions para to each other. R. chlorophenolicus selectively methylated the hydroxyl group flanked by two chlorine substituents. Tetrachlorohydroquinone, trichlorohydroquinone, and 2,6-dichlorohydroquinone were methylated into tetrachloro-4-methoxyphenol, 2,3,5-trichloro-4-methoxyphenol, and 3,5-dichloro-4-methoxyphenol, respectively. Chlorohydroquinones with only one chlorine adjacent to a hydroxyl group were methylated only in trace amounts, and no metabolite was formed from hydroquinone. The degradation intermediates formed in hydroxylation of tetrachloroguaiacol and trichlorosyringol by R. chlorophenolicus were O-methylated into two isomeric trichlorodimethoxyphenols and two isomeric dichlorotrimethoxyphenols, respectively. R. chlorophenolicus also degraded the polychlorinated methylation products (tetrachlorinated and trichlorinated 4-methoxyphenols), but not mono- and dichlorinated 4-methoxyphenols. PMID:16347691

  4. Nitric oxide-mediated intracellular growth restriction of pathogenic Rhodococcus equi can be prevented by iron.

    PubMed

    von Bargen, Kristine; Wohlmann, Jens; Taylor, Gregory Alan; Utermöhlen, Olaf; Haas, Albert

    2011-05-01

    Rhodococcus equi is an intracellular pathogen which causes pneumonia in young horses and in immunocompromised humans. R. equi arrests phagosome maturation in macrophages at a prephagolysosome stage and grows inside a privileged compartment. Here, we show that, in murine macrophages activated with gamma interferon and lipopolysaccharide, R. equi does not multiply but stays viable for at least 24 h. Whereas infection control of other intracellular pathogens by activated macrophages is executed by enhanced phagosome acidification or phagolysosome formation, by autophagy or by the interferon-inducible GTPase Irgm1, none of these mechanisms seems to control R. equi infection. Growth control by macrophage activation is fully mimicked by treatment of resting macrophages with nitric oxide donors, and inhibition of bacterial multiplication by either activation or nitric oxide donors is annihilated by cotreatment of infected macrophages with ferrous sulfate. Transcriptional analysis of the R. equi iron-regulated gene iupT demonstrates that intracellular R. equi encounters iron stress in activated, but not in resting, macrophages and that this stress is relieved by extracellular addition of ferrous sulfate. Our results suggest that nitric oxide is central to the restriction of bacterial access to iron in activated macrophages. PMID:21383050

  5. Production of 3-hydroxypropionic acid from acrylic acid by newly isolated rhodococcus erythropolis LG12.

    PubMed

    Lee, Sang-Hyun; Park, Si Jae; Park, Oh-Jin; Cho, Junhyeong; Rhee, Joo Won

    2009-05-01

    A novel microorganism, designated as LG12, was isolated from soil based on its ability to use acrylic acid as the sole carbon source. An electron microscopic analysis of its morphological characteristics and phylogenetic classification by 16S rRNA homology showed that the LG12 strain belongs to Rhodococcus erythropolis. R. erythropolis LG12 was able to metabolize a high concentration of acrylic acid (up to 40 g/l). In addition, R. erythropolis LG12 exhibited the highest acrylic acid-degrading activity among the tested microorganisms, including R. rhodochrous, R. equi, R. rubber, Candida rugosa, and Bacillus cereus. The effect of the culture conditions of R. erythropolis LG12 on the production of 3-hydroxypropionic acid (3HP) from acrylic acid was also examined. To enhance the production of 3HP, acrylic acid-assimilating activity was induced by adding 1 mM acrylic acid to the culture medium when the cell density reached an OD600 of 5. Further cultivation of R. erythropolis LG12 with 40 g/l of acrylic acid resulted in the production of 17.5 g/l of 3HP with a molar conversion yield of 44% and productivity of 0.22 g/I/h at 30 degrees after 72 h. PMID:19494695

  6. Diversion of phagosome trafficking by pathogenic Rhodococcus equi depends on mycolic acid chain length.

    PubMed

    Sydor, Tobias; von Bargen, Kristine; Hsu, Fong-Fu; Huth, Gitta; Holst, Otto; Wohlmann, Jens; Becken, Ulrike; Dykstra, Tobias; Söhl, Kristina; Lindner, Buko; Prescott, John F; Schaible, Ulrich E; Utermöhlen, Olaf; Haas, Albert

    2013-03-01

    Rhodococcus equi is a close relative of Mycobacterium spp. and a facultative intracellular pathogen which arrests phagosome maturation in macrophages before the late endocytic stage. We have screened a transposon mutant library of R. equi for mutants with decreased capability to prevent phagolysosome formation. This screen yielded a mutant in the gene for β-ketoacyl-(acyl carrier protein)-synthase A (KasA), a key enzyme of the long-chain mycolic acid synthesizing FAS-II system. The longest kasA mutant mycolic acid chains were 10 carbon units shorter than those of wild-type bacteria. Coating of non-pathogenic E. coli with purified wild-type trehalose dimycolate reduced phagolysosome formation substantially which was not the case with shorter kasA mutant-derived trehalose dimycolate. The mutant was moderately attenuated in macrophages and in a mouse infection model, but was fully cytotoxic.Whereas loss of KasA is lethal in mycobacteria, R. equi kasA mutant multiplication in broth was normal proving that long-chain mycolic acid compounds are not necessarily required for cellular integrity and viability of the bacteria that typically produce them. This study demonstrates a central role of mycolic acid chain length in diversion of trafficking by R. equi. PMID:23078612

  7. Biodesulfurization of water-soluble coal-derived material by Rhodococcus rhodochrous IGTS8

    SciTech Connect

    Kilbane, J.J. II; Jackowski, K.

    1991-01-01

    Rhodococcus rhodochrous IGTS8 was previously isolated because of its ability to use coal as its sole source of sulfur for growth. Subsequent growth studies have revealed that IGTS8 is capable of using a variety of organosulfur compounds as sources of sulfur but not carbon. In this paper, the ability of IGTS8 to selectively remove organic sulfur from water-soluble coal-derived material is investigated. The microbial removal of organic sulfur from coal requires microorganisms capable of cleaving carbonsulfur bonds and the accessibility of these bonds to microorganisms. The use of water-soluble coal-derived material effectively overcomes the problem of accessibility and allows the ability of microorganisms to cleave carbonsulfur bonds present in coal-derived material to be assessed directly. Three coals, two coal solubilization procedures, and two methods of biodesulfurization were examined. The results of these experiments reveal that the microbial removal of significant amounts of organic sulfur from watersoluble coal-derived material with treatment times as brief as 24 hours is possible. Moreover, the carbon content and calorific value of biotreated products are largely unaffected. Biotreatment does, however, result in increases in the hydrogen and nitrogen content and a decreased oxygen content of the coal-derived material. The aqueous supernatant obtained from biodesulfurization experiments does not contain sulfate, sulfite, or other forms of soluble sulfur at increased concentrations in comparison with control samples. Sulfur removed from water-soluble coal-derived material appears to be incorporated into biomass.

  8. Structure of the virulence-associated protein VapD from the intracellular pathogen Rhodococcus equi

    PubMed Central

    Whittingham, Jean L.; Blagova, Elena V.; Finn, Ciaran E.; Luo, Haixia; Miranda-CasoLuengo, Raúl; Turkenburg, Johan P.; Leech, Andrew P.; Walton, Paul H.; Murzin, Alexey G.; Meijer, Wim G.; Wilkinson, Anthony J.

    2014-01-01

    Rhodococcus equi is a multi-host pathogen that infects a range of animals as well as immune-compromised humans. Equine and porcine isolates harbour a virulence plasmid encoding a homologous family of virulence-associated proteins associated with the capacity of R. equi to divert the normal processes of endosomal maturation, enabling bacterial survival and proliferation in alveolar macrophages. To provide a basis for probing the function of the Vap proteins in virulence, the crystal structure of VapD was determined. VapD is a monomer as determined by multi-angle laser light scattering. The structure reveals an elliptical, compact eight-stranded β-barrel with a novel strand topology and pseudo-twofold symmetry, suggesting evolution from an ancestral dimer. Surface-associated octyl-β-d-glucoside molecules may provide clues to function. Circular-dichroism spectroscopic analysis suggests that the β-barrel structure is preceded by a natively disordered region at the N-terminus. Sequence comparisons indicate that the core folds of the other plasmid-encoded virulence-associated proteins from R. equi strains are similar to that of VapD. It is further shown that sequences encoding putative R. equi Vap-like proteins occur in diverse bacterial species. Finally, the functional implications of the structure are discussed in the light of the unique structural features of VapD and its partial structural similarity to other β-barrel proteins. PMID:25084333

  9. Transformation of Rhodococcus fascians by High-Voltage Electroporation and Development of R. fascians Cloning Vectors

    PubMed Central

    Desomer, Jan; Dhaese, Patrick; Montagu, Marc Van

    1990-01-01

    The analysis of the virulence determinants of phytopathogenic Rhodococcus fascians has been hampered by the lack of a system for introducing exogenous DNA. We investigated the possibility of genetic transformation of R. fascians by high-voltage electroporation of intact bacterial cells in the presence of plasmid DNA. Electrotransformation in R. fascians D188 resulted in transformation frequencies ranging from 105/μg of DNA to 107/μg of DNA, depending on the DNA concentration. The effects of different electrical parameters and composition of electroporation medium on transformation efficiency are presented. By this transformation method, a cloning vector (pRF28) for R. fascians based on an indigenous 160-kilobase (chloramphenicol and cadmium resistance-encoding) plasmid pRF2 from strain NCPPB 1675 was developed. The origin of replication and the chloramphenicol resistance gene on pRF28 were used to construct cloning vectors that are capable of replication in R. fascians and Escherichia coli. The electroporation method presented was efficient enough to allow detection of the rare integration of replication-deficient pRF28 derivatives in the R. fascians D188 genome via either homologous or illegitimate recombination. Images PMID:16348290

  10. Rhodococcus equi and Arcanobacterium haemolyticum: two "coryneform" bacteria increasingly recognized as agents of human infection.

    PubMed Central

    Linder, R.

    1997-01-01

    Rhodococcus equi and Arcanobacterium haemolyticum, formerly classified in the genus Corynebacterium, are members of the loosely defined taxon "coryneform" bacteria. Although they are the etiologic agents of distinct human infections, both organisms are frequently overlooked, which results in missed or delayed diagnoses. R. equi, long known as an important pathogen of immature horses, has become in the past three decades an opportunistic pathogen of severely immunosuppressed humans. Most cases are secondary to HIV infection. When specifically sought in throat swab cultures, A. haemolyticum is found responsible for 0.5% to 2.5% of bacterial pharyngitis, especially among adolescents. These two microorganisms represent a spectrum of disease in humans: from a mild, common illness to a rare life-threatening infection. Each organism elaborates lipid hydrolyzing enzymes (cholesterol oxidase by R. equi and sphingomyelinase D by A. haemolyticum) that are toxic to animals and humans and damaging to mammalian cell membranes. The participation of the cytotoxins in pathogenicity is discussed. Greater awareness of the properties of these two bacteria may promote faster, more accurate diagnoses and better clinical management. PMID:9204295

  11. Crystallization and preliminary structural analysis of dibenzothiophene monooxygenase (DszC) from Rhodococcus erythropolis

    PubMed Central

    Duan, Xiaolu; Zhang, Liang; Zhou, Daming; Ji, Kaihua; Ma, Ting; Shui, Wenqing; Li, Guoqiang; Li, Xin

    2013-01-01

    Dibenzothiophene (DBT) and its derivatives are typical sulfur compounds found in fossil fuels. These compounds show resistance to the hydrodesulfuriz­ation treatment that is commonly used in industry. Dibenzothiophene monooxygenase (DszC) is responsible for the oxidation of DBT, which is the first and the rate-limiting step in the DBT enzymatic desulfurization 4S pathway. In this study, the crystal structure of DszC from Rhodococcus erythropolis DS-3 is reported. The crystal of native DszC belonged to space group P1, with unit-cell parameters a = 96.16, b = 96.27, c = 98.56 Å, α = 81.03, β = 67.57, γ = 85.84°. To determine the phase, SAD X-ray diffraction data were collected from a SeMet-derivative DszC crystal, which also belonged to space group P1, with unit-cell parameters a = 95.379, b = 95.167, c = 94.891 Å, α = 87.046, β = 70.536, γ = 79.738°. Further structural analysis of DszC is in progress. PMID:23722833

  12. Crystal structure of DszC from Rhodococcus sp. XP at 1.79 Å.

    PubMed

    Liu, Shiheng; Zhang, Conggang; Su, Tiantian; Wei, Tiandi; Zhu, Deyu; Wang, Kang; Huang, Yan; Dong, Yuhui; Yin, Kun; Xu, Sujuan; Xu, Ping; Gu, Lichuan

    2014-09-01

    The dibenzothiophene (DBT) monooxygenase DszC, which is the key initiating enzyme in "4S" metabolic pathway, catalyzes sequential sulphoxidation reaction of DBT to DBT sulfoxide (DBTO), then DBT sulfone (DBTO2). Here, we report the crystal structure of DszC from Rhodococcus sp. XP at 1.79 Å. Intriguingly, two distinct conformations occur in the flexible lid loops adjacent to the active site (residue 280-295, between α9 and α10). They are named "open"' and "closed" state respectively, and might show the status of the free and ligand-bound DszC. The molecular docking results suggest that the reduced FMN reacts with an oxygen molecule at C4a position of the isoalloxazine ring, producing the C4a-(hydro)peroxyflavin intermediate which is stabilized by H391 and S163. H391 may contribute to the formation of the C4a-(hydro)peroxyflavin by acting as a proton donor to the proximal peroxy oxygen, and it might also be involved in the protonation process of the C4a-(hydro)xyflavin. Site-directed mutagenesis study shows that mutations in the residues involved either in catalysis or in flavin or substrate-binding result in a complete loss of enzyme activity, suggesting that the accurate positions of flavin and substrate are crucial for the enzyme activity. PMID:24470304

  13. Remodulation of central carbon metabolic pathway in response to arsenite exposure in Rhodococcus sp. strain NAU‐1

    PubMed Central

    Jain, Raina; Adhikary, Hemanta; Jha, Sanjay; Jha, Anamika; Kumar, G. Naresh

    2012-01-01

    Summary Arsenite‐tolerant bacteria were isolated from an organic farm of Navsari Agricultural University (NAU), Gujarat, India (Latitude: 20°55′39.04″N; Longitude: 72°54′6.34″E). One of the isolates, NAU‐1 (aerobic, Gram‐positive, non‐motile, coccobacilli), was hyper‐tolerant to arsenite (AsIII, 23 mM) and arsenate (AsV, 180 mM). 16S rRNA gene of NAU‐1 was 99% similar to the 16S rRNA genes of Rhodococcus (Accession No. HQ659188). Assays confirmed the presence of membrane bound arsenite oxidase and cytoplasmic arsenate reductase in NAU‐1. Genes for arsenite transporters (arsB and ACR3(1)) and arsenite oxidase gene (aoxB) were confirmed by PCR. Arsenite oxidation and arsenite efflux genes help the bacteria to tolerate arsenite. Specific activities of antioxidant enzymes (catalase, ascorbate peroxidase, superoxide dismutase and glutathione S‐transferase) increased in dose‐dependent manner with arsenite, whereas glutathione reductase activity decreased with increase in AsIII concentration. Metabolic studies revealed that Rhodococcus NAU‐1 produces excess of gluconic and succinic acids, and also activities of glucose dehydrogenase, phosphoenol pyruvate carboxylase and isocitrate lyase were increased, to cope with the inhibited activities of glucose‐6‐phosphate dehydrogenase, pyruvate dehydrogenase and α‐ketoglutarate dehydrogenase enzymes respectively, in the presence of AsIII. Enzyme assays revealed the increase in direct oxidative and glyoxylate pathway in Rhodococcus NAU‐1 in the presence of AsIII. PMID:23062201

  14. Functional divergence of HBHA from Mycobacterium tuberculosis and its evolutionary relationship with TadA from Rhodococcus opacus.

    PubMed

    Lanfranconi, Mariana P; Alvarez, Héctor M

    2016-08-01

    Rhodococcus opacus PD630 and Rhodococcus jostii RHA1 are oleaginous bacteria able to synthesize and accumulate triacylglycerols (TAG) in lipid bodies (LB). Highly relevant to the structure of LB is a protein homologous to heparin-binding hemagglutinin (HBHA) (called TadA in rhodococci), which is a virulence factor found in Mycobacterium tuberculosis. HBHA is an adhesin involved in binding to non-phagocytic cells and extrapulmonary dissemination. We observed a conserved synteny of three genes encoding a transcriptional regulator (TR), the HBHA protein and a membrane protein (MP) between TAG-accumulating actinobacteria belonging to Rhodococcus, Mycobacterium, Nocardia and Dietzia genera, among others. A 354 bp-intergenic spacing containing a SigF-binding site was found between hbha and the TR genes in M. tuberculosis, which was absent in genomes of other investigated actinobacteria. Analyses of available "omic" information revealed that TadA and TR were co-induced in rhodococci under TAG-accumulating conditions; whereas in M. tuberculosis and Mycobacterium smegmatis, HBHA and TR were regulated independently under stress conditions occurring during infection. We also found differences in protein lengths, domain content and distribution between HBHA and TadA proteins from mycobacteria and rhodococci, which may explain their different roles in cells. Based on the combination of results obtained in model actinobacteria, we hypothesize that HBHA and TadA proteins originated from a common ancestor, but later suffered a process of functional divergence during evolution. Thus, rhodococcal TadA probably has maintained its original role; whereas HBHA may have evolved as a virulence factor in pathogenic mycobacteria. PMID:27287527

  15. Degradation of trichloroethene by a linear-plasmid-encoded alkene monooxygenase in Rhodococcus corallinus (Nocardia corallina) B-276.

    PubMed

    Saeki, H; Akira, M; Furuhashi, K; Averhoff, B; Gottschalk, G

    1999-07-01

    Rhodococcus corallinus (formerly Nocardia corallina) B-276, isolated with propene as sole carbon and energy source, is able to oxidize trichloroethene (TCE). Glucose- or propene-grown R. corallinus B-276 cells exhibited no difference in TCE degradation efficiency. TCE degradation was found to be growth-phase-dependent and maximum rates were monitored with stationary-phase cells. K(m) and Vmax values for TCE degradation of R. corallinus B-276 grown in nutrient broth medium in the presence of glucose were 187 microM and 2.4 nmol min-1 (mg protein)-1, respectively. Escherichia coli recombinants harbouring and expressing the alkene monooxygenase genes of R. corallinus B-276 exhibited the ability to degrade TCE. This result provides clear evidence that the alkene monooxygenase of R. corallinus B-276 catalyses TCE oxidation. R. corallinus B-276 was shown to contain four linear plasmids, pNC10 (70 kb), pNC20 (85 kb), pNC30 (185 kb) and pNC40 (235 kb). The observation that pNC30-deficient strains had lost the ability to grow on propene suggested that the genes of the propene degradation pathway are encoded by the linear plasmid pNC30. Southern blot analysis with cloned alkene monooxygenase genes from R. corallinus B-276 revealed a positive hybridization signal with the linear plasmid pNC30. This result clearly shows that the alkene monooxygenase is encoded by the linear plasmid pNC30. Eleven short-chain-alkene-oxidizing strains were screened for the presence of linear plasmids. Among these, four propene-oxidizing Rhodococcus strains and one ethene-oxidizing Mycobacterium strain were found to contain linear megaplasmids. Southern blot analysis with the alkene monooxygenase revealed positive signals with linear plasmids of two propene-oxidizing Rhodococcus ruber strains. These results indicate that homologous alkene monooxygenases are encoded by linear plasmids in R. ruber strains. PMID:10439411

  16. Ketoreductase TpdE from Rhodococcus jostii TMP1: characterization and application in the synthesis of chiral alcohols

    PubMed Central

    Kutanovas, Simonas; Rutkienė, Rasa; Tauraitė, Daiva; Striela, Romualdas; Meškys, Rolandas

    2015-01-01

    Background. Production of highly pure enantiomers of vicinal diols is desirable, but difficult to achieve. Enantiomerically pure diols and acyloins are valuable bulk chemicals, promising synthones and potential building blocks for chiral polymers. Enzymatic reduction of ketones is a useful technique for the synthesis of the desired enantiomeric alcohols. Here, we report on the characterization of a ketoreductase TpdE from Rhodococcus jostii TMP1 that is a prospective tool for the synthesis of such compounds. Results. In this study, NADPH-dependent short-chain dehydrogenase/reductase TpdE from Rhodococcus jostii TMP1 was characterized. The enzyme exhibited broad substrate specificity towards aliphatic 2,3-diketones, butan-3-one-2-yl alkanoates, as well as acetoin and its acylated derivatives. TpdE stereospecifically reduced α-diketones to the corresponding diols. The GC-MS analysis of the reduction products of 2,3- and 3,4-diketones indicated that TpdE is capable of reducing both keto groups in its substrate leading to the formation of two new chiral atoms in the product molecule. Bioconversions of diketones to corresponding diols occurred using either purified enzyme or a whole-cell Escherichia coli BL21 (DE3) biocatalyst harbouring recombinant TpdE. The optimum temperature and pH were determined to be 30–35 °C and 7.5, respectively. Conclusions. The broad substrate specificity and stereoselectivity of TpdE from Rhodococcus jostii TMP1 make it a promising biocatalyst for the production of enantiomerically pure diols that are difficult to obtain by chemical routes. PMID:26587349

  17. Biodegradation of atrazine by Rhodococcus sp. BCH2 to N-isopropylammelide with subsequent assessment of toxicity of biodegraded metabolites.

    PubMed

    Kolekar, Parag D; Phugare, Swapnil S; Jadhav, Jyoti P

    2014-02-01

    Atrazine is a persistent organic pollutant in the environment which affects not only terrestrial and aquatic biota but also human health. Since its removal from the environment is needed, atrazine biodegradation is achieved in the present study using the bacterium Rhodococcus sp. BCH2 isolated from soil, long-term treated with atrazine. The bacterium was capable of degrading about 75 % atrazine in liquid medium having pH 7 under aerobic and dark condition within 7 days. The degradation ability of the bacterium at various temperatures (20-60 °C), pH (range 3-11), carbon (glucose, fructose, sucrose, starch, lactose, and maltose), and nitrogen (ammonium molybdate, sodium nitrate, potassium nitrate, and urea) sources were studied for triumph optimum atrazine degradation. The results indicate that atrazine degradation at higher concentrations (100 ppm) was pH and temperature dependent. However, glucose and potassium nitrate were optimum carbon and nitrogen source, respectively. Atrazine biodegradation analysis was carried out by using high-performance thin-layer chromatography (HPTLC), Fourier transform infrared spectroscopy (FTIR), and liquid chromatography quadrupole time-of-flight (LC/Q-TOF-MS) techniques. LC/Q-TOF-MS analysis revealed formation of various intermediate metabolites including hydroxyatrazine, N-isopropylammelide, deisopropylhydroxyatrazine, deethylatrazine, deisopropylatrazine, and deisopropyldeethylatrazine which was helpful to propose biochemical degradation pathway of atrazine. Furthermore, the toxicological studies of atrazine and its biodegraded metabolites were executed on earthworm Eisenia foetida as a model organism with respect to enzymatic (SOD and Catalase) antioxidant defense mechanism and lipid peroxidation studies. These results suggest innocuous degradation of atrazine by Rhodococcus sp. BCH2 in nontoxic form. Therefore the Rhodococcus sp.BCH2 could prove a valuable source for the eco-friendly biodegradation of atrazine pesticide. PMID

  18. Development of a conductimetric biosensor using immobilised Rhodococcus ruber whole cells for the detection and quantification of acrylonitrile.

    PubMed

    Roach, P C J; Ramsden, D K; Hughes, J; Williams, P

    2003-10-30

    A conductimetric biosensor for the detection of acrylonitrile in solution was designed and characterised using whole cells of Rhodococcus ruber NCIMB 40757, which were immobilised into a disc of dimethyl silicone sponge (ImmobaSil). The biosensor described was capable of the detection and quantification of acrylonitrile in aqueous solution, having a linear response to concentrations between 2 and 50 mM (106-2650 ppm) acrylonitrile. The biosensor has been shown to be reproducible with respect to the data obtained over a number of days, and retains stability for a minimum period of at least 5 days before recalibration of the biosensor is required. PMID:14559001

  19. Comparative Genomics and Metabolic Analysis Reveals Peculiar Characteristics of Rhodococcus opacus Strain M213 Particularly for Naphthalene Degradation

    PubMed Central

    Blom, Jochen; Indest, Karl J.; Jung, Carina M.; Stothard, Paul; Bera, Gopal; Green, Stefan J.; Ogram, Andrew

    2016-01-01

    The genome of Rhodococcus opacus strain M213, isolated from a fuel-oil contaminated soil, was sequenced and annotated which revealed a genome size of 9,194,165 bp encoding 8680 putative genes and a G+C content of 66.72%. Among the protein coding genes, 71.77% were annotated as clusters of orthologous groups of proteins (COGs); 55% of the COGs were present as paralog clusters. Pulsed field gel electrophoresis (PFGE) analysis of M213 revealed the presence of three different sized replicons- a circular chromosome and two megaplasmids (pNUO1 and pNUO2) estimated to be of 750Kb 350Kb in size, respectively. Conversely, using an alternative approach of optical mapping, the plasmid replicons appeared as a circular ~1.2 Mb megaplasmid and a linear, ~0.7 Mb megaplasmid. Genome-wide comparative analysis of M213 with a cohort of sequenced Rhodococcus species revealed low syntenic affiliation with other R. opacus species including strains B4 and PD630. Conversely, a closer affiliation of M213, at the functional (COG) level, was observed with the catabolically versatile R. jostii strain RHA1 and other Rhodococcii such as R. wratislaviensis strain IFP 2016, R. imtechensis strain RKJ300, Rhodococcus sp. strain JVH1, and Rhodococcus sp. strain DK17, respectively. An in-depth, genome-wide comparison between these functional relatives revealed 971 unique genes in M213 representing 11% of its total genome; many associating with catabolic functions. Of major interest was the identification of as many as 154 genomic islands (GEIs), many with duplicated catabolic genes, in particular for PAHs; a trait that was confirmed by PCR-based identification of naphthalene dioxygenase (NDO) as a representative gene, across PFGE-resolved replicons of strain M213. Interestingly, several plasmid/GEI-encoded genes, that likely participate in degrading naphthalene (NAP) via a peculiar pathway, were also identified in strain M213 using a combination of bioinformatics, metabolic analysis and gene

  20. Brief Tale of a Bacteraemia by Rhodococcus equi, With Concomitant Lung Mass: What Came First, the Chicken or The Egg?

    PubMed Central

    Savini, Vincenzo; Salutari, Prassede; Sborgia, Marco; Mancini, Iole; Masciarelli, Gioviana; Catavitello, Chiara; Astolfi, Daniela; D’Amario, Claudio; Fioritoni, Giuseppe; Spadaro, Antonio; D’Antonio, Domenico

    2011-01-01

    Rhodococcus equi is an uncommon Gram positive, variably acid-fast pathogen, that appears as hard to treat mostly owing to the establishment of intracellular niches. Lack of interpretive criteria for susceptibility testing may lead to under-reporting or overestimation of resistances, whereas knowledge about this pathogen’s clinical impact may be affected by erroneous phenotype-based characterization at a genus and species level. We present the case of a bacteraemia with a concomitant lung mass in a lymphoma patient, that further highlights the emergence of rhodococcal diseases as a matter for concern in the fields of infectious diseases and haematology. PMID:21625310

  1. Comparative Genomics and Metabolic Analysis Reveals Peculiar Characteristics of Rhodococcus opacus Strain M213 Particularly for Naphthalene Degradation.

    PubMed

    Pathak, Ashish; Chauhan, Ashvini; Blom, Jochen; Indest, Karl J; Jung, Carina M; Stothard, Paul; Bera, Gopal; Green, Stefan J; Ogram, Andrew

    2016-01-01

    The genome of Rhodococcus opacus strain M213, isolated from a fuel-oil contaminated soil, was sequenced and annotated which revealed a genome size of 9,194,165 bp encoding 8680 putative genes and a G+C content of 66.72%. Among the protein coding genes, 71.77% were annotated as clusters of orthologous groups of proteins (COGs); 55% of the COGs were present as paralog clusters. Pulsed field gel electrophoresis (PFGE) analysis of M213 revealed the presence of three different sized replicons- a circular chromosome and two megaplasmids (pNUO1 and pNUO2) estimated to be of 750Kb 350Kb in size, respectively. Conversely, using an alternative approach of optical mapping, the plasmid replicons appeared as a circular ~1.2 Mb megaplasmid and a linear, ~0.7 Mb megaplasmid. Genome-wide comparative analysis of M213 with a cohort of sequenced Rhodococcus species revealed low syntenic affiliation with other R. opacus species including strains B4 and PD630. Conversely, a closer affiliation of M213, at the functional (COG) level, was observed with the catabolically versatile R. jostii strain RHA1 and other Rhodococcii such as R. wratislaviensis strain IFP 2016, R. imtechensis strain RKJ300, Rhodococcus sp. strain JVH1, and Rhodococcus sp. strain DK17, respectively. An in-depth, genome-wide comparison between these functional relatives revealed 971 unique genes in M213 representing 11% of its total genome; many associating with catabolic functions. Of major interest was the identification of as many as 154 genomic islands (GEIs), many with duplicated catabolic genes, in particular for PAHs; a trait that was confirmed by PCR-based identification of naphthalene dioxygenase (NDO) as a representative gene, across PFGE-resolved replicons of strain M213. Interestingly, several plasmid/GEI-encoded genes, that likely participate in degrading naphthalene (NAP) via a peculiar pathway, were also identified in strain M213 using a combination of bioinformatics, metabolic analysis and gene

  2. Methylated Cytokinins from the Phytopathogen Rhodococcus fascians Mimic Plant Hormone Activity.

    PubMed

    Radhika, Venkatesan; Ueda, Nanae; Tsuboi, Yuuri; Kojima, Mikiko; Kikuchi, Jun; Kudo, Takuji; Sakakibara, Hitoshi

    2015-10-01

    Cytokinins (CKs), a class of phytohormones that regulate plant growth and development, are also synthesized by some phytopathogens to disrupt the hormonal balance and to facilitate niche establishment in their hosts. Rhodococcus fascians harbors the fasciation (fas) locus, an operon encoding several genes homologous to CK biosynthesis and metabolism. This pathogen causes unique leafy gall symptoms reminiscent of CK overproduction; however, bacterial CKs have not been clearly correlated with the severe symptoms, and no virulence-associated unique CKs or analogs have been identified. Here, we report the identification of monomethylated N(6)-(∆(2)-isopentenyl)adenine and dimethylated N(6)-(∆(2)-isopentenyl)adenine (collectively, methylated cytokinins [MeCKs]) from R. fascians. MeCKs were recognized by a CK receptor and up-regulated type-A ARABIDOPSIS THALIANA RESPONSE REGULATOR genes. Treatment with MeCKs inhibited root growth, a hallmark of CK action, whereas the receptor mutant was insensitive. MeCKs were retained longer in planta than canonical CKs and were poor substrates for a CK oxidase/dehydrogenase, suggesting enhanced biological stability. MeCKs were synthesized by S-adenosyl methionine-dependent methyltransferases (MT1 and MT2) that are present upstream of the fas genes. The best substrate for methylation was isopentenyl diphosphate. MT1 and MT2 catalyzed distinct methylation reactions; only the MT2 product was used by FAS4 to synthesize monomethylated N(6)-(∆(2)-isopentenyl)adenine. The MT1 product was dimethylated by MT2 and used as a substrate by FAS4 to produce dimethylated N(6)-(∆(2)-isopentenyl)adenine. Chemically synthesized MeCKs were comparable in activity. Our results strongly suggest that MeCKs function as CK mimics and play a role in this plant-pathogen interaction. PMID:26251309

  3. Isolation and Characterization of Carbendazim-degrading Rhodococcus erythropolis djl-11

    PubMed Central

    Harvey, Paul R.; Li, Hongmei; Ren, Yan; Li, Jishun; Wang, Jianing; Yang, Hetong

    2013-01-01

    Carbendazim (methyl 1H-benzimidazol-2-yl carbamate) is one of the most widely used fungicides in agriculture worldwide, but has been reported to have adverse effects on animal health and ecosystem function. A highly efficient carbendazim-degrading bacterium (strain dj1-11) was isolated from carbendazim-contaminated soil samples via enrichment culture. Strain dj1-11 was identified as Rhodococcus erythropolis based on morphological, physiological and biochemical characters, including sequence analysis of the 16S rRNA gene. In vitro degradation of carbendazim (1000 mg·L−1) by dj1-11 in minimal salts medium (MSM) was highly efficient, and with an average degradation rate of 333.33 mg·L−1·d−1 at 28°C. The optimal temperature range for carbendazim degradation by dj1-11 in MSM was 25–30°C. Whilst strain dj1-11 was capable of metabolizing cabendazim as the sole source of carbon and nitrogen, degradation was significantly (P<0.05) increased by addition of 12.5 mM NH4NO3. Changes in MSM pH (4–9), substitution of NH4NO3 with organic substrates as N and C sources or replacing Mg2+ with Mn2+, Zn2+ or Fe2+ did not significantly affect carbendazim degradation by dj1-11. During the degradation process, liquid chromatography-mass spectrometry (LC-MS) detected the metabolites 2-aminobenzimidazole and 2-hydroxybenzimidazole. A putative carbendazim-hydrolyzing esterase gene was cloned from chromosomal DNA of djl-11 and showed 99% sequence homology to the mheI carbendazim-hydrolyzing esterase gene from Nocardioides sp. SG-4G. PMID:24098350

  4. Improvement of Biodesulfurization Rate of Alginate Immobilized Rhodococcus erythropolis R1

    PubMed Central

    Derikvand, Peyman; Etemadifar, Zahra

    2014-01-01

    Background: Sulfur oxides released from the burning of oil causes severe environmental pollution. The sulfur can be removed via the 4S pathway in biodesulfurization (BDS). Immobilization approaches have been developed to prevent cell contamination of oil during the BDS process. Objectives: The encapsulation of Rhodococcus erythropolis R1 in calcium alginate beads was studied in order to enhance conversion of dibenzothiophene (DBT) to 2-hydroxy biphenyl (2-HBP) as the final product. Also the effect of different factors on the BDS process was investigated. Materials and Methods: Calcium alginate capsules were prepared using peristaltic pumps with different needle sizes to control the beads sizes. Scanning electron microscopy and flow cytometry methods were used to study the distribution and viability of encapsulated cells, respectively. Two non-ionic surfactants and also nano Ƴ-Al2O3were used with the ratio of 0.5% (v/v) and 1:5 (v/v) respectively to investigate their BDS efficiency. In addition, the effect of different bead sizes and different concentrations of sodium alginate in BDS activity was studied. Results: The 2% (w/v) sodium alginate beads with 1.5mm size were found to be the optimum for beads stability and efficient 2-HBP production. The viability of encapsulated cells decreased by 12% after 20 h of desulfurization, compared to free cells. Adding the non-ionic surfactants markedly enhanced the rate of BDS, because of increasing mass transfer of DBT to the gel matrix. In addition, Span 80 was more effective than Tween 80. The nanoƳ-Al2O3 particles could increase BDS rate by up to two-folds greater than that of the control beads. Conclusions: The nano Ƴ-Al2O3 can improve the immobilized biocatalyst for excellent efficiency of DBT desulfurization. Also the BDS activity can be enhanced by setting the other explained factors at optimum levels. PMID:25147685

  5. Transcriptomic Assessment of Isozymes in the Biphenyl Pathway of Rhodococcus sp. Strain RHA1†

    PubMed Central

    Gonçalves, Edmilson R.; Hara, Hirofumi; Miyazawa, Daisuke; Davies, Julian E.; Eltis, Lindsay D.; Mohn, William W.

    2006-01-01

    Rhodococcus sp. RHA1 grows on a broad range of aromatic compounds and vigorously degrades polychlorinated biphenyls (PCBs). Previous work identified RHA1 genes encoding multiple isozymes for most of the seven steps of the biphenyl (BPH) pathway, provided evidence for coexpression of some of these isozymes, and indicated the involvement of some of these enzymes in the degradation of BPH, ethylbenzene (ETB), and PCBs. To investigate the expression of these isozymes and better understand how they contribute to the robust degradative capacity of RHA1, we comprehensively analyzed the 9.7-Mb genome of RHA1 for BPH pathway genes and characterized the transcriptome of RHA1 growing on benzoate (BEN), BPH, and ETB. Sequence analyses revealed 54 potential BPH pathway genes, including 28 not previously reported. Transcriptomic analysis with a DNA microarray containing 70-mer probes for 8,213 RHA1 genes revealed a suite of 320 genes of diverse functions that were upregulated during growth both on BPH and on ETB, relative to growth on the control substrate, pyruvate. By contrast, only 65 genes were upregulated during growth on BEN. Quantitative PCR assays confirmed microarray results for selected genes and indicated that some of the catabolic genes were upregulated over 10,000-fold. Our analysis suggests that up to 22 enzymes, including 8 newly identified ones, may function in the BPH pathway of RHA1. The relative expression levels of catabolic genes did not differ for BPH and ETB, suggesting a common regulatory mechanism. This study delineated a suite of catabolic enzymes for biphenyl and alkyl-benzenes in RHA1, which is larger than previously recognized and which may serve as a model for catabolism in other environmentally important bacteria having large genomes. PMID:16957245

  6. In vitro synergy, pharmacodynamics, and postantibiotic effect of 11 antimicrobial agents against Rhodococcus equi.

    PubMed

    Giguère, Steeve; Lee, Elise A; Guldbech, Kristen M; Berghaus, Londa J

    2012-11-01

    There are no studies investigating interactions between clarithromycin or azithromycin and rifampin or other commonly used antimicrobial agents against virulent isolates of Rhodococcus equi. In addition, there is no published data on the postantibiotic effects (PAEs) and pharmacodynamics properties of antimicrobial agents against R. equi. The objectives were to assess in vitro interactions, pharmacodynamics, and PAEs of 11 antimicrobial agents belonging to various antimicrobial classes against R. equi. Antimicrobial agents investigated (erythromycin, clarithromycin, azithromycin, rifampin, amikacin, gentamicin, enrofloxacin, vancomycin, imipenem, ceftiofur, and doxycycline) were selected based on in vitro activity against large numbers of isolates of R. equi and frequency of use in foals or humans infected with R. equi. Three virulent strains of R. equi were evaluated by time-kill curves and checkerboard assays, and the postantibiotic effect was measured at 5×MIC. Only amikacin, gentamicin, enrofloxacin, and vancomycin were bactericidal against R. equi. Combinations including a macrolide (erythromycin, clarithromycin, azithromycin) and either rifampin or doxycycline, and the combination doxycycline-rifampin were synergistic. Combinations containing amikacin and erythromycin, clarithromycin, azithromycin, or rifampin and the combination gentamicin-rifampin were antagonistic. The PAEs of rifampin, erythromycin, clarithromycin, vancomycin, and doxycycline were relatively long with median values ranging between 4.5 and 6.5h. Azithromycin, gentamicin, and imipenem had intermediate PAEs ranging between 3.3 and 3.5h. Amikacin, enrofloxacin, and ceftiofur had shorter PAEs ranging between 1.3 and 2.1h. Gentamicin, amikacin, enrofloxacin, and doxycycline exhibited concentration-dependent activity whereas erythromycin, clarithromycin, azithromycin, rifampin, ceftiofur, imipenem, and vancomycin exhibited time-dependent activity against R. equi. PMID:22704561

  7. Retrospective comparison of azithromycin, clarithromycin, and erythromycin for the treatment of foals with Rhodococcus equi pneumonia.

    PubMed

    Giguère, Steeve; Jacks, Stephanie; Roberts, Gregory D; Hernandez, Jorge; Long, Maureen T; Ellis, Christina

    2004-01-01

    The objective of this retrospective study was to compare the efficacy of azithromycin-rifampin, clarithromycin-rifampin, and erythromycin-rifampin for the treatment of pneumonia caused by Rhodococcus equi in foals. Eighty-one foals with naturally acquired pneumonia caused by R. equi were included in the study. Information on age, sex, breed, physical examination findings, laboratory testing, and thoracic radiography was abstracted from each medical record. Foals were divided in 3 groups based on the antimicrobial agent selected for therapy. Short-term (discharge from the hospital) and long-term (apparently healthy as a yearling) success rates, days of hospitalization, days with fever, days with tachypnea, and percentage of radiographic improvement were compared among groups. Foals treated with clarithromycin-rifampin had significantly (P = .02) higher odds of overall short-term (odds ratio [OR] = 12.2) and long-term (OR = 20.6) treatment success and significantly fewer days with fever than foals treated with erythromycin-rifampin. Foals treated with clarithromycin-rifampin had a significantly (P = .03) higher percentage of radiographic improvement and a tendency (P = .06) toward higher odds of overall short-term (OR = 8.1) and long-term (OR = 11.8) treatment success compared to foals treated with azithromycin-rifampin. Among foals with severe radiographic lesions, the success rates of foals treated with clarithromycin-rifampin both short-term (88%) and long-term (83%) were significantly (P = .02) higher than that of foals treated with azithromycin-rifampin (0%). For each treatment group, the only reported adverse effect was diarrhea that was mild and self-limiting in most cases. The combination clarithromycin-rifampin is superior to azithromycin-rifampin or erythromycin-rifampin for the treatment of pneumonia caused by R. equi in foals in a referral population. PMID:15320600

  8. Mutant prevention concentration and mutant selection window for 10 antimicrobial agents against Rhodococcus equi.

    PubMed

    Berghaus, Londa J; Giguère, Steeve; Guldbech, Kristen

    2013-10-25

    The objectives of this study were to determine the mutant prevention concentration (MPC), time above the MPC and mutant selection window for 10 antimicrobial agents against Rhodococcus equi and to determine if the combination of a macrolide with rifampin would decrease emergence of resistant mutants. Antimicrobial agents investigated (erythromycin, clarithromycin, azithromycin, rifampin, amikacin, gentamicin, enrofloxacin, vancomycin, imipenem, and doxycycline) were selected based on in vitro activity and frequency of use in foals or people infected with R. equi. Each antimicrobial agent or combination of agents was evaluated against four virulent strains of R. equi. MPC were determined using an agar plate assay. Pharmacodynamic parameters were calculated using published plasma and pulmonary pharmacokinetic variables. There was a significant (P<0.001) effect of the type of antimicrobial agent on the MPC. The MPC of clarithromycin (1.0 μg/ml) was significantly lower and the MPC of rifampin and amikacin (512 and 384 μg/ml, respectively) were significantly higher than that of all other antimicrobial agents tested. Combining erythromycin, clarithromycin, or azithromycin with rifampin resulted in a significant (P≤0.005) decrease in MPC and MPC/MIC ratio. When MIC and MPC were combined with pharmacokinetic variables, only gentamicin and vancomycin were predicted to achieve plasma concentrations above the MPC for any given periods of time. Only clarithromycin and the combination clarithromycin-rifampin were predicted to achieve concentrations in bronchoalveolar cells and pulmonary epithelial lining fluid above the MPC for the entire dosing interval. In conclusion, the combination of a macrolide with rifampin considerably decreases the emergence of resistant mutants of R. equi. PMID:23915992

  9. Rhodococcus erythropolis BG43 Genes Mediating Pseudomonas aeruginosa Quinolone Signal Degradation and Virulence Factor Attenuation.

    PubMed

    Müller, Christine; Birmes, Franziska S; Rückert, Christian; Kalinowski, Jörn; Fetzner, Susanne

    2015-11-01

    Rhodococcus erythropolis BG43 is able to degrade the Pseudomonas aeruginosa quorum sensing signal molecules PQS (Pseudomonas quinolone signal) [2-heptyl-3-hydroxy-4(1H)-quinolone] and HHQ [2-heptyl-4(1H)-quinolone] to anthranilic acid. Based on the hypothesis that degradation of HHQ might involve hydroxylation to PQS followed by dioxygenolytic cleavage of the heterocyclic ring and hydrolysis of the resulting N-octanoylanthranilate, the genome was searched for corresponding candidate genes. Two gene clusters, aqdA1B1C1 and aqdA2B2C2, each predicted to code for a hydrolase, a flavin monooxygenase, and a dioxygenase related to 1H-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase, were identified on circular plasmid pRLCBG43 of strain BG43. Transcription of all genes was upregulated by PQS, suggesting that both gene clusters code for alkylquinolone-specific catabolic enzymes. An aqdR gene encoding a putative transcriptional regulator, which was also inducible by PQS, is located adjacent to the aqdA2B2C2 cluster. Expression of aqdA2B2C2 in Escherichia coli conferred the ability to degrade HHQ and PQS to anthranilic acid; however, for E. coli transformed with aqdA1B1C1, only PQS degradation was observed. Purification of the recombinant AqdC1 protein verified that it catalyzes the cleavage of PQS to form N-octanoylanthranilic acid and carbon monoxide and revealed apparent Km and kcat values for PQS of ∼27 μM and 21 s(-1), respectively. Heterologous expression of the PQS dioxygenase gene aqdC1 or aqdC2 in P. aeruginosa PAO1 quenched the production of the virulence factors pyocyanin and rhamnolipid and reduced the synthesis of the siderophore pyoverdine. Thus, the toolbox of quorum-quenching enzymes is expanded by new PQS dioxygenases. PMID:26319870

  10. Chloroquine inhibits Rhodococcus equi replication in murine and foal alveolar macrophages by iron-starvation.

    PubMed

    Gressler, Leticia T; Bordin, Angela I; McQueen, Cole M; Cohen, Noah D; de Vargas, Agueda Castagna

    2016-05-30

    Rhodococcus equi preferentially infects macrophages causing pyogranulomatous pneumonia in young foals. Both the vapA and rhbC genes are up-regulated in an iron (Fe)-deprived environment, such as that found within macrophages. Chloroquine (CQ) is a drug widely used against malaria that suppresses the intracellular availability of Fe in eukaryotic cells. The main objective of this study was to evaluate the ability of CQ to inhibit replication of virulent R. equi within murine (J774A.1) and foal alveolar macrophages (AMs) and to verify whether the mechanism of inhibition could be Fe-deprivation-dependent. CQ effect on R. equi extracellular survival and toxicity to J774A.1 were evaluated. R. equi survival within J774A.1 and foal AMs was evaluated under CQ (10 and 20μM), bovine saturated transferrin (bHTF), and bovine unsaturated transferrin (bATF) exposure. To explore the action mechanism of CQ, the superoxide anion production, the lysozyme activity, as well as the relative mRNA expression of vapA and rhbC were examined. CQ at≤20μM had no effect on R. equi extracellular multiplication and J774A.1 viability. Exposure to CQ significantly and markedly reduced survival of R. equi within J774A.1 and foal AMs. Treatment with bHTF did not reverse CQ effect on R. equi. Exposure to CQ did not affected superoxide anion production or lysozyme activity, however vapA and rhbC expression was significantly increased. Our results reinforce the hypothesis that intracellular availability of Fe is required for R. equi survival, and our initial hypothesis that CQ can limit replication of R. equi in J774A.1 and foal AMs, most likely by Fe starvation. PMID:27139025

  11. Two Transporters Essential for Reassimilation of Novel Cholate Metabolites by Rhodococcus jostii RHA1

    PubMed Central

    Swain, Kendra; Casabon, Israël; Eltis, Lindsay D.

    2012-01-01

    The bacterial uptake of steroids and their metabolites remains poorly understood. We investigated two transporters associated with cholate catabolism in Rhodococcus jostii RHA1. Reverse transcriptase quantitative-PCR indicated that an ATP-binding cassette (ABC) transporter and a major facilitator superfamily (MFS) transporter were upregulated 16.7- and 174-fold, respectively, during the exponential phase of growth on cholate compared to growth on pyruvate. Gene knockout analysis established that these transporters are required for the reassimilation of distinct metabolites that accumulate during growth on cholate. The ABC transporter, encoded by camABCD, was essential for uptake of 1β(2′-propanoate)-3aα-H-4α(3″(R)-hydroxy-3″-propanoate)-7aβ-methylhexahydro-5-indanone and a desaturated analog. The MFS transporter, encoded by camM, was essential for uptake of 3,7(R),12(S)-trihydroxy-9-oxo-9,10-seco-23,24-bisnorchola-1,3,5(10)-trien-22-oate. These metabolites differ from cholate metabolites reported to be excreted by proteobacteria in that they retain an isopropanoyl side chain at C-17. The uptake of these metabolites was necessary for maximal growth on cholate: a ΔcamB mutant lacking the permease component of the ABC transporter and a ΔcamM mutant lacking the MFS transporter grew to 74% and 77%, respectively, of the yield of the wild type. This study demonstrates for the first time the requirement for specific transporters for uptake of cholate metabolites and highlights the importance and complexity of transport processes associated with bacterial steroid catabolism. PMID:23024344

  12. The intracellular bacterium Rhodococcus equi requires Mac-1 to bind to mammalian cells.

    PubMed Central

    Hondalus, M K; Diamond, M S; Rosenthal, L A; Springer, T A; Mosser, D M

    1993-01-01

    Rhodococcus equi is a facultative intracellular bacterium of macrophages that causes disease in immunocompromised individuals, particularly those with AIDS. In this report, we demonstrate that R. equi binding to mammalian cells requires complement and is mediated primarily by the leukocyte complement receptor, Mac-1. Bacteria bind to macrophages poorly unless exogenous complement is added to the incubation medium. The addition of fresh nonimmune serum, which contains no detectable antibodies to R. equi, greatly enhances bacterial binding to macrophages, whereas heat inactivation of this serum or immunological depletion of C3 from the serum reduces binding to levels only slightly higher than those of binding under serum-free conditions. Human serum depleted of C2 or C4 is fully opsonic, indicating that complement activation and fixation occur by the alternative pathway. The serum-dependent binding of rhodococci to macrophages is mediated primarily by the macrophage complement receptor type 3, Mac-1 (CD11b/CD18). Bacteria do not bind to fibroblastoid or epithelial cells that lack this receptor. Most of the bacterial binding to macrophages is inhibited by a monoclonal antibody to Mac-1 but is unaffected by a monoclonal antibody to complement receptor type 1. Furthermore, opsonized, but not unopsonized, bacteria bind to purified Mac-1 immobilized on plastic. In addition, in the presence of opsonic complement, rhodococci bind efficiently to fibroblastoid cells transfected with cloned Mac-1 but relatively poorly to cells transfected with the complement receptor type 1. Hence, R. equi fixes complement by activating the alternative complement pathway, and this fixation is a requirement for bacterial adhesion and invasion. Furthermore, complement fixation defines rhodococcal host cell tropism, since R. equi binds specifically and exclusively to cells expressing Mac-1. Images PMID:8514396

  13. Plasmid Profiles of Virulent Rhodococcus equi Strains Isolated from Infected Foals in Poland.

    PubMed

    Kalinowski, Marcin; Grądzki, Zbigniew; Jarosz, Łukasz; Kato, Kiyoko; Hieda, Yu; Kakuda, Tsutomu; Takai, Shinji

    2016-01-01

    Rhodococcus equi is an important bacterial pathogen in foals up to 6 months old, widespread in horse farms all over the world. It was found that only virulent R. equi strains expressing 15-17 kDa virulence-associated protein (VapA) and having large virulence plasmid of 85-90 kb containing vapA gene are pathogenic for horses. To date, 12 plasmid types have been reported in VapA positive strains from horses. There are no data concerning plasmid types of Polish field R. equi strains isolated from horses and horse farm environment. The aim of the study is to determine plasmid profiles of virulent R. equi strains isolated in Poland from dead foals as well as from soil samples taken from horse breeding farms. Plasmid profiles of 10 clinical strains derived from 8 farms and 11 environmental strains from 3 farms, confirmed as virulent by PCR, were compared with 12 reference strains containing the known plasmid size and type. Plasmid DNAs were analysed by digestion with the restriction endonucleases BamHI, EcoRI, EcoT22I, and HindIII for detailed comparison and estimation of plasmid sizes. The results of RFLP analysis revealed that all except one isolates used in the study are classified as VapA 85 kb type I plasmid. One strain harboured VapA 87 kb type I plasmid. This is the first report of plasmid types of Polish field R. equi strains. The results of our preliminary investigations on horse farms located in central and eastern Poland indicate that the virulent R. equi strains thus far isolated from diseased foals and horse farms environment represent a highly uniform plasmid pattern. PMID:27074033

  14. Peripheral blood lymphocyte subpopulations and immunoglobulin concentrations in healthy foals and foals with Rhodococcus equi pneumonia.

    PubMed

    Flaminio, M J; Rush, B R; Shuman, W

    1999-01-01

    Infectious diseases are common in foals aged 1-5 months. The objectives of this investigation were to evaluate immunologic parameters in foals from birth to weaning to establish reference values for the proportion of circulating lymphocytes that were helper (CD4+) or cytotoxic (CD8+) T cells, or B cells; to measure serum immunoglobulin (IgM and IgG) concentrations; and to compare these immunologic parameters to values in foals with naturally occurring Rhodococcus equi pneumonia and in adult horses. Peripheral blood lymphocyte subpopulations were determined by flow cytometric analysis, and serum IgG and IgM concentrations were determined by radial immunodiffusion. Flow cytometric analysis of lymphocyte subpopulations suggested age-related changes in the cell-mediated immune system in horses. Absolute circulating CD4+ and CD8+ T lymphocytes and B cells increased linearly up to 3 months of age. Circulating B cell concentrations from birth to 6 months of age were greater than values in adult horses and the lymphocyte differences among the age groups are mainly due to variation in B lymphocytes. Both absolute and proportional B cell concentrations were greater in foals with R equi pneumonia than in healthy foals at the same age. The increase in absolute cell counts of each subpopulation was dependent on the increase of absolute peripheral blood lymphocyte count. Serum IgG concentration increased linearly from 1 to 3 months of age, and serum IgM concentrations increased from 1 to 6 months of age. These data suggest age-dependent cell-mediated and humoral development in young foals. PMID:10357110

  15. Experimental infection of neonatal foals with Rhodococcus equi triggers adult-like gamma interferon induction.

    PubMed

    Jacks, Stephanie; Giguère, Steeve; Crawford, P Cynda; Castleman, William L

    2007-06-01

    Rhodococcus equi is a facultative intracellular pathogen that causes pneumonia in young foals but does not induce disease in immunocompetent adult horses. Clearance of R. equi depends mainly on gamma interferon (IFN-gamma) production by T lymphocytes, whereas the predominance of interleukin 4 (IL-4) is detrimental. Young foals, like neonates of many other species, are generally deficient in the ability to produce IFN-gamma. The objective of this study was to compare the cytokine profiles, as well as cell-mediated and antibody responses, of young foals to those of adult horses following intrabronchial challenge with R. equi. The lymphoproliferative responses of bronchial lymph node (BLN) cells to concanavalin A were significantly higher in foals than in adult horses. In contrast, adult horses had significantly higher lymphoproliferative responses to R. equi antigens than did foals. Infected foals had significantly lower IL-4 mRNA expression but significantly higher IFN-gamma expression and IFN-gamma/IL-4 ratio in R. equi-stimulated BLN lymphocytes than did infected adults. Infection with R. equi in foals resulted in a significant increase in the percentage of T lymphocytes and CD4(+) T lymphocytes in bronchoalveolar lavage fluid in association with a significant decrease in the percentage of these cell populations in BLNs. Infection of foals also resulted in a marked increase in serum immunoglobulin Ga (IgGa) and IgGb levels, resulting in concentrations in serum that were significantly higher than those of adult horses. This study demonstrates that the immune response to R. equi in foals is not biased toward IL-4 and is characterized by the predominant induction of IFN-gamma. PMID:17409222

  16. Experimental Infection of Neonatal Foals with Rhodococcus equi Triggers Adult-Like Gamma Interferon Induction▿

    PubMed Central

    Jacks, Stephanie; Giguère, Steeve; Crawford, P. Cynda; Castleman, William L.

    2007-01-01

    Rhodococcus equi is a facultative intracellular pathogen that causes pneumonia in young foals but does not induce disease in immunocompetent adult horses. Clearance of R. equi depends mainly on gamma interferon (IFN-γ) production by T lymphocytes, whereas the predominance of interleukin 4 (IL-4) is detrimental. Young foals, like neonates of many other species, are generally deficient in the ability to produce IFN-γ. The objective of this study was to compare the cytokine profiles, as well as cell-mediated and antibody responses, of young foals to those of adult horses following intrabronchial challenge with R. equi. The lymphoproliferative responses of bronchial lymph node (BLN) cells to concanavalin A were significantly higher in foals than in adult horses. In contrast, adult horses had significantly higher lymphoproliferative responses to R. equi antigens than did foals. Infected foals had significantly lower IL-4 mRNA expression but significantly higher IFN-γ expression and IFN-γ/IL-4 ratio in R. equi-stimulated BLN lymphocytes than did infected adults. Infection with R. equi in foals resulted in a significant increase in the percentage of T lymphocytes and CD4+ T lymphocytes in bronchoalveolar lavage fluid in association with a significant decrease in the percentage of these cell populations in BLNs. Infection of foals also resulted in a marked increase in serum immunoglobulin Ga (IgGa) and IgGb levels, resulting in concentrations in serum that were significantly higher than those of adult horses. This study demonstrates that the immune response to R. equi in foals is not biased toward IL-4 and is characterized by the predominant induction of IFN-γ. PMID:17409222

  17. Virulence Plasmid of Rhodococcus equi Contains Inducible Gene Family Encoding Secreted Proteins

    PubMed Central

    Byrne, Barbara A.; Prescott, John F.; Palmer, Guy H.; Takai, Shinji; Nicholson, Vivian M.; Alperin, Debra C.; Hines, Stephen A.

    2001-01-01

    Rhodococcus equi causes severe pyogranulomatous pneumonia in foals. This facultative intracellular pathogen produces similar lesions in immunocompromised humans, particularly in AIDS patients. Virulent strains of R. equi bear a large plasmid that is required for intracellular survival within macrophages and for virulence in foals and mice. Only two plasmid-encoded proteins have been described previously; a 15- to 17-kDa surface protein designated virulence-associated protein A (VapA) and an antigenically related 20-kDa protein (herein designated VapB). These two proteins are not expressed by the same R. equi isolate. We describe here the substantial similarity between VapA and VapB. Moreover, we identify three additional genes carried on the virulence plasmid, vapC, -D, and -E, that are tandemly arranged downstream of vapA. These new genes are members of a gene family and encode proteins that are approximately 50% homologous to VapA, VapB, and each other. vapC, -D, and -E are found only in R. equi strains that express VapA and are highly conserved in VapA-positive isolates from both horses and humans. VapC, -D, and -E are secreted proteins coordinately regulated by temperature with VapA; the proteins are expressed when R. equi is cultured at 37°C but not at 30°C, a finding that is compatible with a role in virulence. As secreted proteins, VapC, -D, and -E may represent targets for the prevention of rhodococcal pneumonia. An immunologic study using VapA-specific antibodies and recombinant Vap proteins revealed no evidence of cross-reactivity despite extensive sequence similarity over the carboxy terminus of all four proteins. PMID:11159951

  18. γ-Resorcylate Catabolic-Pathway Genes in the Soil Actinomycete Rhodococcus jostii RHA1

    PubMed Central

    Kasai, Daisuke; Araki, Naoto; Motoi, Kota; Yoshikawa, Shota; Iino, Toju; Imai, Shunsuke; Masai, Eiji

    2015-01-01

    The Rhodococcus jostii RHA1 gene cluster required for γ-resorcylate (GRA) catabolism was characterized. The cluster includes tsdA, tsdB, tsdC, tsdD, tsdR, tsdT, and tsdX, which encode GRA decarboxylase, resorcinol 4-hydroxylase, hydroxyquinol 1,2-dioxygenase, maleylacetate reductase, an IclR-type regulator, a major facilitator superfamily transporter, and a putative hydrolase, respectively. The tsdA gene conferred GRA decarboxylase activity on Escherichia coli. Purified TsdB oxidized NADH in the presence of resorcinol, suggesting that tsdB encodes a unique NADH-specific single-component resorcinol 4-hydroxylase. Mutations in either tsdA or tsdB resulted in growth deficiency on GRA. The tsdC and tsdD genes conferred hydroxyquinol 1,2-dioxygenase and maleylacetate reductase activities, respectively, on E. coli. Inactivation of tsdT significantly retarded the growth of RHA1 on GRA. The growth retardation was partially suppressed under acidic conditions, suggesting the involvement of tsdT in GRA uptake. Reverse transcription-PCR analysis revealed that the tsd genes constitute three transcriptional units, the tsdBADC and tsdTX operons and tsdR. Transcription of the tsdBADC and tsdTX operons was induced during growth on GRA. Inactivation of tsdR derepressed transcription of the tsdBADC and tsdTX operons in the absence of GRA, suggesting that tsd gene transcription is negatively regulated by the tsdR-encoded regulator. Binding of TsdR to the tsdR-tsdB and tsdT-tsdR intergenic regions was inhibited by the addition of GRA, indicating that GRA interacts with TsdR as an effector molecule. PMID:26319878

  19. Association between radiographic pattern and outcome in foals with pneumonia caused by Rhodococcus equi.

    PubMed

    Giguère, Steeve; Roberts, Gregory D

    2012-01-01

    Our objective was to characterize the association between types of radiographic findings and outcome in foals with pneumonia caused by Rhodococcus equi. Admission lateral thoracic radiographs of 62 foals with culture-confirmed R. equi pneumonia were reviewed retrospectively. A scoring system was developed to individually assess the severity of alveolar pattern, interstitial pattern, tracheobronchial lymphadenopathy, pleural effusion, and the number of nodular opacities and cavitary lesions. Individual scores were added to obtain a total radiographic score ranging from 0 (normal) to 22. Forty-three of 62 foals (69%) survived to discharge. The median total radiographic score of nonsurvivors (14; range, 9-16) was significantly (P = 0.007) higher than that of survivors (11; range, 4-15). Foals with a total radiographic score of greater than or equal to 15 were 6.15 times (95% CI: 1.35 to 28.2) less likely to survive than foals with a lower score (P = 0.019). A multivariate logistic regression model was used to identify the potential associations between specific types of radiographic lesions and outcome. The model was statistically significant (P = 0.002) and correctly classified 75.8% of foals. Only severity of alveolar pattern and number of cavitary lesions made statistically significant contributions to the model. There was no significant association between concurrent isolation of other bacteria along with R. equi and the types or severity of radiographic lesions. Based on the results of this study, severity of alveolar pattern and number of cavitary lesions are the radiographic findings significantly associated with a poor outcome in foals with R. equi pneumonia. PMID:22742474

  20. Cloning, purification and characterization of two components of phenol hydroxylase from Rhodococcus erythropolis UPV-1.

    PubMed

    Saa, Laura; Jaureguibeitia, Arrate; Largo, Eneko; Llama, María J; Serra, Juan L

    2010-03-01

    Phenol hydroxylase that catalyzes the conversion of phenol to catechol in Rhodococcus erythropolis UPV-1 was identified as a two-component flavin-dependent monooxygenase. The two proteins are encoded by the genes pheA1 and pheA2, located very closely in the genome. The sequenced pheA1 gene was composed of 1,629 bp encoding a protein of 542 amino acids, whereas the pheA2 gene consisted of 570 bp encoding a protein of 189 amino acids. The deduced amino acid sequences of both genes showed high homology with several two-component aromatic hydroxylases. The genes were cloned separately in cells of Escherichia coli M15 as hexahistidine-tagged proteins, and the recombinant proteins His(6)PheA1 and His(6)PheA2 were purified and its catalytic activity characterized. His(6)PheA1 exists as a homotetramer of four identical subunits of 62 kDa that has no phenol hydroxylase activity on its own. His(6)PheA2 is a homodimeric flavin reductase, consisting of two identical subunits of 22 kDa, that uses NAD(P)H in order to reduce flavin adenine dinucleotide (FAD), according to a random sequential kinetic mechanism. The reductase activity was strongly inhibited by thiol-blocking reagents. The hydroxylation of phenol in vitro requires the presence of both His(6)PheA1 and His(6)PheA2 components, in addition to NADH and FAD, but the physical interaction between the proteins is not necessary for the reaction. PMID:19787347

  1. Rhodococcus erythropolis BG43 Genes Mediating Pseudomonas aeruginosa Quinolone Signal Degradation and Virulence Factor Attenuation

    PubMed Central

    Müller, Christine; Birmes, Franziska S.; Rückert, Christian; Kalinowski, Jörn

    2015-01-01

    Rhodococcus erythropolis BG43 is able to degrade the Pseudomonas aeruginosa quorum sensing signal molecules PQS (Pseudomonas quinolone signal) [2-heptyl-3-hydroxy-4(1H)-quinolone] and HHQ [2-heptyl-4(1H)-quinolone] to anthranilic acid. Based on the hypothesis that degradation of HHQ might involve hydroxylation to PQS followed by dioxygenolytic cleavage of the heterocyclic ring and hydrolysis of the resulting N-octanoylanthranilate, the genome was searched for corresponding candidate genes. Two gene clusters, aqdA1B1C1 and aqdA2B2C2, each predicted to code for a hydrolase, a flavin monooxygenase, and a dioxygenase related to 1H-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase, were identified on circular plasmid pRLCBG43 of strain BG43. Transcription of all genes was upregulated by PQS, suggesting that both gene clusters code for alkylquinolone-specific catabolic enzymes. An aqdR gene encoding a putative transcriptional regulator, which was also inducible by PQS, is located adjacent to the aqdA2B2C2 cluster. Expression of aqdA2B2C2 in Escherichia coli conferred the ability to degrade HHQ and PQS to anthranilic acid; however, for E. coli transformed with aqdA1B1C1, only PQS degradation was observed. Purification of the recombinant AqdC1 protein verified that it catalyzes the cleavage of PQS to form N-octanoylanthranilic acid and carbon monoxide and revealed apparent Km and kcat values for PQS of ∼27 μM and 21 s−1, respectively. Heterologous expression of the PQS dioxygenase gene aqdC1 or aqdC2 in P. aeruginosa PAO1 quenched the production of the virulence factors pyocyanin and rhamnolipid and reduced the synthesis of the siderophore pyoverdine. Thus, the toolbox of quorum-quenching enzymes is expanded by new PQS dioxygenases. PMID:26319870

  2. Identification of a Novel Self-Sufficient Styrene Monooxygenase from Rhodococcus opacus 1CP▿ †

    PubMed Central

    Tischler, Dirk; Eulberg, Dirk; Lakner, Silvia; Kaschabek, Stefan R.; van Berkel, Willem J. H.; Schlömann, Michael

    2009-01-01

    Sequence analysis of a 9-kb genomic fragment of the actinobacterium Rhodococcus opacus 1CP led to identification of an open reading frame encoding a novel fusion protein, StyA2B, with a putative function in styrene metabolism via styrene oxide and phenylacetic acid. Gene cluster analysis indicated that the highly related fusion proteins of Nocardia farcinica IFM10152 and Arthrobacter aurescens TC1 are involved in a similar physiological process. Whereas 413 amino acids of the N terminus of StyA2B are highly similar to those of the oxygenases of two-component styrene monooxygenases (SMOs) from pseudomonads, the residual 160 amino acids of the C terminus show significant homology to the flavin reductases of these systems. Cloning and functional expression of His10-StyA2B revealed for the first time that the fusion protein does in fact catalyze two separate reactions. Strictly NADH-dependent reduction of flavins and highly enantioselective oxygenation of styrene to (S)-styrene oxide were shown. Inhibition studies and photometric analysis of recombinant StyA2B indicated the absence of tightly bound heme and flavin cofactors in this self-sufficient monooxygenase. StyA2B oxygenates a spectrum of aromatic compounds similar to those of two-component SMOs. However, the specific activities of the flavin-reducing and styrene-oxidizing functions of StyA2B are one to two orders of magnitude lower than those of StyA/StyB from Pseudomonas sp. strain VLB120. PMID:19482928

  3. Identification of Genomic Loci Associated with Rhodococcus equi Susceptibility in Foals

    PubMed Central

    McQueen, Cole M.; Doan, Ryan; Dindot, Scott V.; Bourquin, Jessica R.; Zlatev, Zlatomir Z.; Chaffin, M. Keith; Blodgett, Glenn P.; Ivanov, Ivan; Cohen, Noah D.

    2014-01-01

    Pneumonia caused by Rhodococcus equi is a common cause of disease and death in foals. Although agent and environmental factors contribute to the incidence of this disease, the genetic factors influencing the clinical outcomes of R. equi pneumonia are ill-defined. Here, we performed independent single nucleotide polymorphism (SNP)- and copy number variant (CNV)-based genome-wide association studies to identify genomic loci associated with R. equi pneumonia in foals. Foals at a large Quarter Horse breeding farm were categorized into 3 groups: 1) foals with R. equi pneumonia (clinical group [N = 43]); 2) foals with ultrasonographic evidence of pulmonary lesions that never developed clinical signs of pneumonia (subclinical group [N = 156]); and, 3) foals without clinical signs or ultrasonographic evidence of pneumonia (unaffected group [N = 49]). From each group, 24 foals were randomly selected and used for independent SNP- and CNV-based genome-wide association studies (GWAS). The SNP-based GWAS identified a region on chromosome 26 that had moderate evidence of association with R. equi pneumonia when comparing clinical and subclinical foals. A joint analysis including all study foals revealed a 3- to 4-fold increase in odds of disease for a homozygous SNP within the associated region when comparing the clinical group with either of the other 2 groups of foals or their combination. The region contains the transient receptor potential cation channel, subfamily M, member 2 (TRPM2) gene, which is involved in neutrophil function. No associations were identified in the CNV-based GWAS. Collectively, these data identify a region on chromosome 26 associated with R. equi pneumonia in foals, providing evidence that genetic factors may indeed contribute to this important disease of foals. PMID:24892408

  4. IcgA Is a Virulence Factor of Rhodococcus equi That Modulates Intracellular Growth

    PubMed Central

    Wang, Xiaoguang; Coulson, Garry B.; Miranda-CasoLuengo, Aleksandra A.; Miranda-CasoLuengo, Raúl; Hondalus, Mary K.

    2014-01-01

    Virulence of the intracellular pathogen Rhodococcus equi depends on a 21.3-kb pathogenicity island located on a conjugative plasmid. To date, the only nonregulatory pathogenicity island-encoded virulence factor identified is the cell envelope-associated VapA protein. Although the pathogenicity islands from porcine and equine R. equi isolates have undergone major rearrangements, the virR operon (virR-icgA-vapH-orf7-virS) is highly conserved in both, suggesting these genes play an important role in pathogenicity. VirR and VirS are transcriptional regulators controlling expression of pathogenicity island genes, including vapA. Here, we show that while vapH and orf7 are dispensable for intracellular growth of R. equi, deletion of icgA, formerly known as orf5, encoding a major facilitator superfamily transport protein, elicited an enhanced growth phenotype in macrophages and a significant reduction in macrophage viability, while extracellular growth in broth remained unaffected. Transcription of virS, located downstream of icgA, and vapA was not affected by the icgA deletion during growth in broth or in macrophages, showing that the enhanced growth phenotype caused by deletion of icgA was not mediated through abnormal transcription of these genes. Transcription of icgA increased 6-fold within 2 h following infection of macrophages and remained significantly higher 48 h postinfection compared to levels at the start of the infection. The major facilitator superfamily transport protein IcgA is the first factor identified in R. equi that negatively affects intracellular replication. Aside from VapA, it is only the second pathogenicity island-encoded structural protein shown to play a direct role in intracellular growth of this pathogenic actinomycete. PMID:24549327

  5. DNA sequence and comparison of virulence plasmids from Rhodococcus equi ATCC 33701 and 103.

    PubMed

    Takai, S; Hines, S A; Sekizaki, T; Nicholson, V M; Alperin, D A; Osaki, M; Takamatsu, D; Nakamura, M; Suzuki, K; Ogino, N; Kakuda, T; Dan, H; Prescott, J F

    2000-12-01

    The virulence plasmids of the equine virulent strains Rhodococcus equi ATCC 33701 and 103 were sequenced, and their genetic structure was analyzed. p33701 was 80,610 bp in length, and p103 was 1 bp shorter; their sequences were virtually identical. The plasmids contained 64 open reading frames (ORFs), 22 of which were homologous with genes of known function and 3 of which were homologous with putative genes of unknown function in other species. Putative functions were assigned to five ORFs based on protein family characteristics. The most striking feature of the virulence plasmids was the presence of a 27,536-bp pathogenicity island containing seven virulence-associated protein (vap) genes, including vapA. These vap genes have extensive homology to vapA, which encodes a thermoregulated and surface-expressed protein. The pathogenicity island contained a LysR family transcriptional regulator and a two-component response regulator upstream of six of the vap genes. The vap genes were present as a cluster of three (vapA, vapC, and vapD), as a pair (vapE and vapF), or individually (vapG; vapH). A region of extensive direct repeats of unknown function, possibly associated with thermoregulation, was present immediately upstream of the clustered and the paired genes but not the individual vap genes. There was extensive homology among the C-terminal halves of all vap genes but not generally among the N-terminal halves. The remainder of the plasmid consisted of a large region which appears to be associated with conjugation functions and a large region which appears to be associated with replication and partitioning functions. PMID:11083803

  6. Plasmid Profiles of Virulent Rhodococcus equi Strains Isolated from Infected Foals in Poland

    PubMed Central

    Kalinowski, Marcin; Grądzki, Zbigniew; Jarosz, Łukasz; Kato, Kiyoko; Hieda, Yu; Kakuda, Tsutomu; Takai, Shinji

    2016-01-01

    Rhodococcus equi is an important bacterial pathogen in foals up to 6 months old, widespread in horse farms all over the world. It was found that only virulent R. equi strains expressing 15–17 kDa virulence-associated protein (VapA) and having large virulence plasmid of 85–90 kb containing vapA gene are pathogenic for horses. To date, 12 plasmid types have been reported in VapA positive strains from horses. There are no data concerning plasmid types of Polish field R. equi strains isolated from horses and horse farm environment. The aim of the study is to determine plasmid profiles of virulent R. equi strains isolated in Poland from dead foals as well as from soil samples taken from horse breeding farms. Plasmid profiles of 10 clinical strains derived from 8 farms and 11 environmental strains from 3 farms, confirmed as virulent by PCR, were compared with 12 reference strains containing the known plasmid size and type. Plasmid DNAs were analysed by digestion with the restriction endonucleases BamHI, EcoRI, EcoT22I, and HindIII for detailed comparison and estimation of plasmid sizes. The results of RFLP analysis revealed that all except one isolates used in the study are classified as VapA 85 kb type I plasmid. One strain harboured VapA 87 kb type I plasmid. This is the first report of plasmid types of Polish field R. equi strains. The results of our preliminary investigations on horse farms located in central and eastern Poland indicate that the virulent R. equi strains thus far isolated from diseased foals and horse farms environment represent a highly uniform plasmid pattern. PMID:27074033

  7. Methylated Cytokinins from the Phytopathogen Rhodococcus fascians Mimic Plant Hormone Activity1[OPEN

    PubMed Central

    Radhika, Venkatesan; Ueda, Nanae; Tsuboi, Yuuri; Kojima, Mikiko; Kikuchi, Jun; Kudo, Takuji; Sakakibara, Hitoshi

    2015-01-01

    Cytokinins (CKs), a class of phytohormones that regulate plant growth and development, are also synthesized by some phytopathogens to disrupt the hormonal balance and to facilitate niche establishment in their hosts. Rhodococcus fascians harbors the fasciation (fas) locus, an operon encoding several genes homologous to CK biosynthesis and metabolism. This pathogen causes unique leafy gall symptoms reminiscent of CK overproduction; however, bacterial CKs have not been clearly correlated with the severe symptoms, and no virulence-associated unique CKs or analogs have been identified. Here, we report the identification of monomethylated N6-(∆2-isopentenyl)adenine and dimethylated N6-(∆2-isopentenyl)adenine (collectively, methylated cytokinins [MeCKs]) from R. fascians. MeCKs were recognized by a CK receptor and up-regulated type-A ARABIDOPSIS THALIANA RESPONSE REGULATOR genes. Treatment with MeCKs inhibited root growth, a hallmark of CK action, whereas the receptor mutant was insensitive. MeCKs were retained longer in planta than canonical CKs and were poor substrates for a CK oxidase/dehydrogenase, suggesting enhanced biological stability. MeCKs were synthesized by S-adenosyl methionine-dependent methyltransferases (MT1 and MT2) that are present upstream of the fas genes. The best substrate for methylation was isopentenyl diphosphate. MT1 and MT2 catalyzed distinct methylation reactions; only the MT2 product was used by FAS4 to synthesize monomethylated N6-(∆2-isopentenyl)adenine. The MT1 product was dimethylated by MT2 and used as a substrate by FAS4 to produce dimethylated N6-(∆2-isopentenyl)adenine. Chemically synthesized MeCKs were comparable in activity. Our results strongly suggest that MeCKs function as CK mimics and play a role in this plant-pathogen interaction. PMID:26251309

  8. A Case of Recurrent Meningitis Caused by Rhodococcus species Successfully Treated with Antibiotic Treatment and Intrathecal Injection of Vancomycin through an Ommaya Reservoir

    PubMed Central

    Lee, Kanglok; Rho, Min; Yu, Miyeon; Kwak, Joohee; Hong, Seungpyo; Kim, Jisoong; Kim, Yeonjae

    2015-01-01

    Human infection by Rhodococcus species is rare and mostly limited to immunocompromised hosts such as patients infected with the human immunodeficiency virus (HIV) or organ transplant recipients. The most common strain is R. equi, and the most common clinical presentation is pulmonary infection, reported in 80% of Rhodococcus spp. infections. The central nervous system is an uncommon infection site. We report a case of a patient with pneumonia, brain abscess, and recurrent meningitis caused by Rhodococcus spp. He initially presented with pneumonia with necrosis, which progressed to brain abscess and recurrent meningitis. Rhodococcus spp. was identified from the cerobrospinal fluid (CSF) collected during his fourth hospital admission. Despite prolonged treatment with appropriate antibiotics, meningitis recurred three times. Finally, in order to administer antibiotics directly into the CSF and bypass the blood-brain barrier, an Ommaya reservoir was inserted for administration of 90 days of intrathecal vancomycin and amikacin in conjunction with intravenous and oral antibiotics; the patient was finally cured with this treatment regimen. PMID:26483993

  9. Draft Genome Sequence of Rhodococcus rhodochrous Strain KG-21, a Soil Isolate from Oil Fields of Krishna-Godavari Basin, India

    PubMed Central

    Dawar, Chhavi

    2015-01-01

    Here, we present the 6.1-Mb draft genome sequence of Rhodococcus rhodochrous strain KG-21, a soil isolate from the oil fields of Krishna-Godavari Basin in Andhra Pradesh, India. This genomic resource may help in the identification of the gene(s) involved in hydrocarbon degradation and their possible deployment for bioremediation. PMID:26472842

  10. Draft Genome Sequence of a Versatile Hydrocarbon-Degrading Bacterium, Rhodococcus pyridinivorans Strain KG-16, Collected from Oil Fields in India

    PubMed Central

    Dawar, Chhavi; Phanindranath, R.; Mutnuri, Lakshmi; Dayal, Anurodh M.

    2016-01-01

    We describe here a 5.8-Mb draft genome sequence of Rhodococcus pyridinivorans strain KG-16, which was obtained from the soil samples collected from the oilfields of Krishna-Godavari basin in India. This genomic resource can provide insights into the pathways and mechanisms of hydrocarbon degradation and potentially aid in bioremediation applications. PMID:26868394

  11. Biotransformation of d-Limonene to (+) trans-Carveol by Toluene-Grown Rhodococcus opacus PWD4 Cells

    PubMed Central

    Duetz, Wouter A.; Fjällman, Ann H. M.; Ren, Shuyu; Jourdat, Catherine; Witholt, Bernard

    2001-01-01

    The toluene-degrading strain Rhodococcus opacus PWD4 was found to hydroxylate d-limonene exclusively in the 6-position, yielding enantiomerically pure (+) trans-carveol and traces of (+) carvone. This biotransformation was studied using cells cultivated in chemostat culture with toluene as a carbon and energy source. The maximal specific activity of (+) trans-carveol formation was 14.7 U (g of cells [dry weight])−1, and the final yield was 94 to 97%. Toluene was found to be a strong competitive inhibitor of the d-limonene conversion. Glucose-grown cells did not form any trans-carveol from d-limonene. These results suggest that one of the enzymes involved in toluene degradation is responsible for this allylic monohydroxylation. Another toluene degrader (Rhodococcus globerulus PWD8) had a lower specific activity but was found to oxidize most of the formed trans-carveol to (+) carvone, allowing for the biocatalytic production of this flavor compound. PMID:11375201

  12. Isolation and characterization of styrene metabolism genes from styrene-assimilating soil bacteria Rhodococcus sp. ST-5 and ST-10.

    PubMed

    Toda, Hiroshi; Itoh, Nobuya

    2012-01-01

    Styrene metabolism genes were isolated from styrene-assimilating bacteria Rhodococcus sp. ST-5 and ST-10. Strain ST-5 had a gene cluster containing four open reading frames which encoded styrene degradation enzymes. The genes showed high similarity to styABCD of Pseudomonas sp. Y2. On the other hand, strain ST-10 had only two genes which encoded styrene monooxygenase and flavin oxidoreductase (styAB). Escherichia coli transformants possessing the sty genes of strains ST-5 and ST-10 produced (S)-styrene oxide from styrene, indicating that these genes function as styrene degradation enzymes. Metabolite analysis by resting-cell reaction with gas chromatography-mass spectrometry revealed that strain ST-5 converts styrene to phenylacetaldehyde via styrene oxide by styrene oxide isomerase (styC) reaction. On the other hand, strain ST-10 lacked this enzyme, and thus accumulated styrene oxide as an intermediate. HPLC analysis showed that styrene oxide was spontaneously isomerized to phenylacetaldehyde by chemical reaction. The produced phenylacetaldehyde was converted to phenylacetic acid (PAA) in strain ST-10 as well as in strain ST-5. Furthermore, phenylacetic acid was converted to phenylacetyl-CoA by the catalysis of phenylacetate-CoA ligase in strains ST-5 and ST-10. This study proposes possible styrene metabolism pathways in Rhodococcus sp. strains ST-5 and ST-10. PMID:21996027

  13. Expression and characterization of styrene monooxygenases of Rhodococcus sp. ST-5 and ST-10 for synthesizing enantiopure (S)-epoxides.

    PubMed

    Toda, Hiroshi; Imae, Ryouta; Komio, Tomoko; Itoh, Nobuya

    2012-10-01

    Styrene monooxygenase (StyA, SMOA)- and flavin oxidoreductase (StyB, SMOB)-coding genes of styrene-assimilating bacteria Rhodococcus sp. ST-5 and ST-10 were successfully expressed in Escherichia coli. Determined amino acid sequences of StyAs and StyBs of ST-5 and ST-10 showed more similarity with those of Pseudomonas than with self-sufficient styrene monooxygenase (StyA2B) of Rhodococcus. Recombinant enzymes were purified from E. coli cells as functional proteins, and their properties were characterized in detail. StyBs (flavin oxidoreductase) of strains ST-5 and ST-10 have similar enzymatic properties to those of Pseudomonas, but StyB of strain ST-10 exhibited higher temperature stability than that of strain ST-5. StyAs of strains ST-5 and ST-10 catalyzed the epoxidation of vinyl side-chain of styrene and its derivatives and produced (S)-epoxides from styrene derivatives and showed high stereoselectivity. Both StyAs showed higher specific activity on halogenated styrene derivatives than on styrene itself. Additionally, the enzymes could catalyze the epoxidation of short-chain 1-alkenes to the corresponding (S)-epoxides. Aromatic compounds including styrene, 3-chlorostyrene, styrene oxide, and benzene exhibited marked inhibition of SMO reaction, although linear 1-alkene showed no inhibition of SMO activity at any concentration. PMID:22258641

  14. Rhodococcus erythropolis DCL14 Contains a Novel Degradation Pathway for Limonene

    PubMed Central

    van der Werf, Mariët J.; Swarts, Henk J.; de Bont, Jan A. M.

    1999-01-01

    Strain DCL14, which is able to grow on limonene as a sole source of carbon and energy, was isolated from a freshwater sediment sample. This organism was identified as a strain of Rhodococcus erythropolis by chemotaxonomic and genetic studies. R. erythropolis DCL14 also assimilated the terpenes limonene-1,2-epoxide, limonene-1,2-diol, carveol, carvone, and (−)-menthol, while perillyl alcohol was not utilized as a carbon and energy source. Induction tests with cells grown on limonene revealed that the oxygen consumption rates with limonene-1,2-epoxide, limonene-1,2-diol, 1-hydroxy-2-oxolimonene, and carveol were high. Limonene-induced cells of R. erythropolis DCL14 contained the following four novel enzymatic activities involved in the limonene degradation pathway of this microorganism: a flavin adenine dinucleotide- and NADH-dependent limonene 1,2-monooxygenase activity, a cofactor-independent limonene-1,2-epoxide hydrolase activity, a dichlorophenolindophenol-dependent limonene-1,2-diol dehydrogenase activity, and an NADPH-dependent 1-hydroxy-2-oxolimonene 1,2-monooxygenase activity. Product accumulation studies showed that (1S,2S,4R)-limonene-1,2-diol, (1S,4R)-1-hydroxy-2-oxolimonene, and (3R)-3-isopropenyl-6-oxoheptanoate were intermediates in the (4R)-limonene degradation pathway. The opposite enantiomers [(1R,2R,4S)-limonene-1,2-diol, (1R,4S)-1-hydroxy-2-oxolimonene, and (3S)-3-isopropenyl-6-oxoheptanoate] were found in the (4S)-limonene degradation pathway, while accumulation of (1R,2S,4S)-limonene-1,2-diol from (4S)-limonene was also observed. These results show that R. erythropolis DCL14 metabolizes both enantiomers of limonene via a novel degradation pathway that starts with epoxidation at the 1,2 double bond forming limonene-1,2-epoxide. This epoxide is subsequently converted to limonene-1,2-diol, 1-hydroxy-2-oxolimonene, and 7-hydroxy-4-isopropenyl-7-methyl-2-oxo-oxepanone. This lactone spontaneously rearranges to form 3-isopropenyl-6-oxoheptanoate. In

  15. Rhodococcus erythropolis DCL14 contains a novel degradation pathway for limonene.

    PubMed

    van der Werf, M J; Swarts, H J; de Bont, J A

    1999-05-01

    Strain DCL14, which is able to grow on limonene as a sole source of carbon and energy, was isolated from a freshwater sediment sample. This organism was identified as a strain of Rhodococcus erythropolis by chemotaxonomic and genetic studies. R. erythropolis DCL14 also assimilated the terpenes limonene-1,2-epoxide, limonene-1,2-diol, carveol, carvone, and (-)-menthol, while perillyl alcohol was not utilized as a carbon and energy source. Induction tests with cells grown on limonene revealed that the oxygen consumption rates with limonene-1,2-epoxide, limonene-1,2-diol, 1-hydroxy-2-oxolimonene, and carveol were high. Limonene-induced cells of R. erythropolis DCL14 contained the following four novel enzymatic activities involved in the limonene degradation pathway of this microorganism: a flavin adenine dinucleotide- and NADH-dependent limonene 1, 2-monooxygenase activity, a cofactor-independent limonene-1, 2-epoxide hydrolase activity, a dichlorophenolindophenol-dependent limonene-1,2-diol dehydrogenase activity, and an NADPH-dependent 1-hydroxy-2-oxolimonene 1,2-monooxygenase activity. Product accumulation studies showed that (1S,2S,4R)-limonene-1,2-diol, (1S, 4R)-1-hydroxy-2-oxolimonene, and (3R)-3-isopropenyl-6-oxoheptanoate were intermediates in the (4R)-limonene degradation pathway. The opposite enantiomers [(1R,2R,4S)-limonene-1,2-diol, (1R, 4S)-1-hydroxy-2-oxolimonene, and (3S)-3-isopropenyl-6-oxoheptanoate] were found in the (4S)-limonene degradation pathway, while accumulation of (1R,2S,4S)-limonene-1,2-diol from (4S)-limonene was also observed. These results show that R. erythropolis DCL14 metabolizes both enantiomers of limonene via a novel degradation pathway that starts with epoxidation at the 1,2 double bond forming limonene-1,2-epoxide. This epoxide is subsequently converted to limonene-1,2-diol, 1-hydroxy-2-oxolimonene, and 7-hydroxy-4-isopropenyl-7-methyl-2-oxo-oxepanone. This lactone spontaneously rearranges to form 3-isopropenyl-6-oxoheptanoate

  16. Engineering xylose metabolism in triacylglycerol-producing Rhodococcus opacus for lignocellulosic fuel production

    PubMed Central

    2013-01-01

    Background There has been a great deal of interest in fuel productions from lignocellulosic biomass to minimize the conflict between food and fuel use. The bioconversion of xylose, which is the second most abundant sugar present after glucose in lignocellulosic biomass, is important for the development of cost effective bioprocesses to fuels. Rhodococcus opacus PD630, an oleaginous bacterium, accumulates large amounts of triacylglycerols (TAGs), which can be processed into advanced liquid fuels. However, R. opacus PD630 does not metabolize xylose. Results We generated DNA libraries from a Streptomyces bacterium capable of utilizing xylose and introduced them into R. opacus PD630. Xsp8, one of the engineered strains, was capable of growing on up to 180 g L-1 of xylose. Xsp8 grown in batch-cultures derived from unbleached kraft hardwood pulp hydrolysate containing 70 g L-1 total sugars was able to completely and simultaneously utilize xylose and glucose present in the lignocellulosic feedstock, and yielded 11.0 g L-1 of TAGs as fatty acids, corresponding to 45.8% of the cell dry weight. The yield of total fatty acids per gram of sugars consumed was 0.178 g, which consisted primarily of palmitic acid and oleic acid. The engineered strain Xsp8 was introduced with two heterologous genes from Streptomyces: xylA, encoding xylose isomerase, and xylB, encoding xylulokinase. We further demonstrated that in addition to the introduction and the concomitant expression of heterologous xylA and xylB genes, there is another molecular target in the R. opacus genome which fully enables the functionality of xylA and xylB genes to generate the robust xylose-fermenting strain capable of efficiently producing TAGs at high xylose concentrations. Conclusion We successfully engineered a R. opacus strain that is capable of completely utilizing high concentrations of xylose or mixed xylose/glucose simultaneously, and substantiated its suitability for TAG production. This study demonstrates

  17. Identification of Rhodococcus equi lipids recognized by host cytotoxic T lymphocytes

    PubMed Central

    Harris, Seth P.; Fujiwara, Nagatoshi; Mealey, Robert H.; Alperin, Debra C.; Naka, Takashi; Goda, Reina

    2010-01-01

    Immune adult horses have CD8+ cytotoxic T lymphocytes (CTLs) that recognize and lyse Rhodococcus equi-infected cells in an equine lymphocyte alloantigen (ELA)-A [classical major histocompatibility complex (MHC) class I]-unrestricted fashion. As protein antigens are MHC class I-restricted, the lack of restriction suggests that the bacterial antigens being recognized by the host are not proteins. The goals of this study were to test the hypothesis that these CTLs recognize unique R. equi cell-wall lipids related to mycobacterial lipids. Initial experiments showed that treatment of soluble R. equi antigen with broadly reactive proteases did not significantly diminish the ability of the antigen to stimulate R. equi-specific CTLs. R. equi-specific CTLs were also shown to lyse target cells (equine macrophages) pulsed with an R. equi lipid extract. Analysis of the R. equi lipid by TLC and MS (MALDI-TOF and ES) indicated that the extracted antigen consisted of three primary fractions: trehalose monomycolate (TMM), trehalose dimycolate (TDM) and cardiolipin (CL). ELA-A-mismatched cells pulsed with purified TMM and CL, but not the TDM fraction, were recognized and lysed by R. equi-specific CTLs. Because of their role in immune clearance and pathogenesis, transcription of the cytokines gamma interferon (IFN-γ) and interleukin-4 (IL-4) was also measured in response to R. equi lipids by using real-time PCR; elevated IFN-γ, but not IL-4, was associated with host clearance of the bacteria. The whole-cell R. equi lipid and all three R. equi lipid fractions resulted in marked increases in IFN-γ transcription, but no increase in IL-4 transcription. Together, these data support the hypothesis that immune recognition of unique lipids in the bacterial cell wall is an important component of the protective immune response to R. equi. The results also identify potential lipid antigens not previously shown to be recognized by CTLs in an important, naturally occurring actinomycete

  18. In vitro susceptibilities of Rhodococcus equi and other common equine pathogens to azithromycin, clarithromycin, and 20 other antimicrobials.

    PubMed

    Jacks, Stephanie S; Giguère, Steeve; Nguyen, An

    2003-05-01

    The objective of this study was to determine in vitro activities of azithromycin (AZM), clarithromycin (CLR), and 20 other antimicrobial agents against Rhodococcus equi and other common equine bacterial pathogens. A total of 201 bacterial isolates from various equine clinical samples were examined. CLR was more active than AZM against R. equi, with MICs at which 90% of the isolates were inhibited of 0.12 and 1.0 micro g/ml, respectively. Other antimicrobial agents highly active against at least 90% of R. equi isolates in vitro included rifampin, gentamicin, and imipenem. Both AZM and CLR showed good activity against beta-hemolytic streptococci and Staphylococcus spp. AZM was more active than other macrolides against Pasteurella spp. and Salmonella enterica. PMID:12709351

  19. Immobilization of Rhodococcus rhodochrous BX2 (an acetonitrile-degrading bacterium) with biofilm-forming bacteria for wastewater treatment.

    PubMed

    Li, Chunyan; Li, Yue; Cheng, Xiaosong; Feng, Liping; Xi, Chuanwu; Zhang, Ying

    2013-03-01

    In this study, a unique biofilm consisting of three bacterial strains with high biofilm-forming capability (Bacillus subtilis E2, E3, and N4) and an acetonitrile-degrading bacterium (Rhodococcus rhodochrous BX2) was established for acetonitrile-containing wastewater treatment. The results indicated that this biofilm exhibited strong resistance to acetonitrile loading shock and displayed a typical spatial and structural heterogeneity and completely depleted the initial concentration of acetonitrile (800mgL(-1)) within 24h in a moving-bed-biofilm reactor (MBBR) after operation for 30days. The immobilization of BX2 cells in the biofilm was confirmed by PCR-DGGE. It has been demonstrated that biofilm-forming bacteria can promote the immobilization of contaminant-degrading bacteria in the biofilms and can subsequently improve the degradation of contaminants in wastewater. This approach offers a novel strategy for enhancing biological oxidation of toxic pollutants in wastewater. PMID:23376196

  20. Transfer of a CD4+ Th1 cell line to nude mice effects clearance of Rhodococcus equi from the lung.

    PubMed Central

    Kanaly, S T; Hines, S A; Palmer, G H

    1996-01-01

    Rhodococcus equi, and intracellular respiratory pathogen, causes sever e granulomatous pneumonia in humans with AIDS and in young horses. Pulmonary clearance of R. equi requires functional CD4+ T cells and gamma interferon (IFN-gamma) expression from bronchial lymph node cells. The purpose of this study was to investigate whether R. equi-specific CD4+ Th1 cells could effect clearance of R. equi from the lung. Adoptive transfer of a clearance of R. equi from the lungs. In contrast, mice transfused with a R. equi-specific CD4+ Th2 cell line expressed interleukin-4 but not IFN-gamma mRNA, failed to clear pulmonary infection, and developed granulomas in the lung. Control mice, which did not receive cells, did not produce IFN-gamma or interleukin-4 and developed small pulmonary granulomas. These results clearly show that a Th1 response is sufficient to effect pulmonary clearance of R. equi. PMID:8606068

  1. Identification of Atypical Rhodococcus-Like Clinical Isolates as Dietzia spp. by 16S rRNA Gene Sequencing▿

    PubMed Central

    Pilares, Lilian; Agüero, Jesús; Vázquez-Boland, José A.; Martínez-Martínez, Luis; Navas, Jesús

    2010-01-01

    Rhodococcus equi and Dietzia spp. are closely related actinomycetes that show similar phenotypic properties. In humans, R. equi is an opportunistic pathogen associated with severe immunodeficiency. Dietzia spp. are environmental bacteria that have been isolated recently from clinical material and are presumptively associated with human infections. During the last 5 years, 15 bacterial isolates from human clinical samples collected at the Hospital Marqués de Valdecilla, Santander, Spain, were identified as R. equi by the API Coryne test. 16S rRNA gene sequencing confirmed seven isolates to be true R. equi strains, whereas the other eight were identified as members of the genus Dietzia, including Dietzia maris (four isolates), Dietzia natronolimnaea (two isolates), and Dietzia timorensis and Dietzia sp. (one isolate each). The eight Dietzia isolates were highly sensitive to 12 antimicrobial compounds. PMID:20220156

  2. Cloning and Characterization of Benzoate Catabolic Genes in the Gram-Positive Polychlorinated Biphenyl Degrader Rhodococcus sp. Strain RHA1

    PubMed Central

    Kitagawa, Wataru; Miyauchi, Keisuke; Masai, Eiji; Fukuda, Masao

    2001-01-01

    Benzoate catabolism is thought to play a key role in aerobic bacterial degradation of biphenyl and polychlorinated biphenyls (PCBs). Benzoate catabolic genes were cloned from a PCB degrader, Rhodococcus sp. strain RHA1, by using PCR amplification and temporal temperature gradient electrophoresis separation. A nucleotide sequence determination revealed that the deduced amino acid sequences encoded by the RHA1 benzoate catabolic genes, benABCDK, exhibit 33 to 65% identity with those of Acinetobacter sp. strain ADP1. The gene organization of the RHA1 benABCDK genes differs from that of ADP1. The RHA1 benABCDK region was localized on the chromosome, in contrast to the biphenyl catabolic genes, which are located on linear plasmids. Escherichia coli cells containing RHA1 benABCD transformed benzoate to catechol via 2-hydro-1,2-dihydroxybenzoate. They transformed neither 2- nor 4-chlorobenzoates but did transform 3-chlorobenzoate. The RHA1 benA gene was inactivated by insertion of a thiostrepton resistance gene. The resultant mutant strain, RBD169, neither grew on benzoate nor transformed benzoate, and it did not transform 3-chlorobenzoate. It did, however, exhibit diminished growth on biphenyl and growth repression in the presence of a high concentration of biphenyl (13 mM). These results indicate that the cloned benABCD genes could play an essential role not only in benzoate catabolism but also in biphenyl catabolism in RHA1. Six rhodococcal benzoate degraders were found to have homologs of RHA1 benABC. In contrast, two rhodococcal strains that cannot transform benzoate were found not to have RHA1 benABC homologs, suggesting that many Rhodococcus strains contain benzoate catabolic genes similar to RHA1 benABC. PMID:11673430

  3. The Rhodococcus opacus TadD protein mediates triacylglycerol metabolism by regulating intracellular NAD(P)H pools

    PubMed Central

    2013-01-01

    Background The Gram-positive actinomycete Rhodococcus opacus is widely studied for its innate ability to store large amounts of carbon in the form of triacylglycerol (TAG). Several groups have demonstrated that R. opacus PD630 is capable of storing anywhere from 50 to 76% of its cell dry weight as TAG. While numerous studies have focused on phenomenological aspects of this process, few have sought to identify the underlying molecular and biochemical mechanisms responsible for the biosynthesis and storage of this molecule. Results Herein we further our previous efforts to illuminate the black box that is lipid metabolism in actinomycetes using a genetic approach. Utilizing a simple, colorimetric genetic screen, we have identified a gene, referred to herein as tadD (triacylglycerol accumulation deficient), which is critical for TAG biosynthesis in R. opacus PD630. Furthermore, we demonstrate that the purified protein product of this gene is capable of oxidizing glyceraldehyde-3-phosphate, while simultaneously reducing NAD(P)+ to NAD(P)H. Supporting this biochemical data, we observed that the ratio of NAD(P)H to NAD(P)+ is elevated in wildtype cultures grown under lipid production conditions as compared to cultures grown under vegetative growth conditions, while the mutant strain demonstrated no change irrespective of growth conditions. Finally, we demonstrate that over-expressing a putative phosphorylative glyceraldehyde-3-phosphate dehydrogenase leads to decreased TAG production during growth on TAG accumulation conditions. Conclusion Taken together, the data support the identification of a key metabolic branch point separating vegetative growth and lipid accumulation lifestyles in Rhodococcus. PMID:24209886

  4. Biodegradation of chlorimuron-ethyl and the associated degradation pathway by Rhodococcus sp. D310-1.

    PubMed

    Li, Chunyan; Zang, Hailian; Yu, Qi; Lv, Tongyang; Cheng, Yi; Cheng, Xiaosong; Liu, Keran; Liu, Wanjun; Xu, Pianpian; Lan, Chuanzeng

    2016-05-01

    Chlorimuron-ethyl is a typical long-term residual sulfonylurea herbicide, and strategies for its removal have attracted increasing attention. Microbial degradation is considered the most acceptable dissipation method. In this study, we optimized the cultivation conditions (substrate concentration, pH, inoculum concentration, and temperature) of the chlorimuron-ethyl-degrading bacterium Rhodococcus sp. D310-1 using response surface methodology (RSM) to improve the biodegradation efficiency. A maximum biodegradation rate of 88.95 % was obtained. The Andrews model was used to describe the changes in the specific degradation rate as the substrate concentration increased. Chlorimuron-ethyl could be transformed with a maximum specific degradation rate (q max), half-saturation constant (K S), and inhibition constant (K i) of 0.4327 day(-1), 63.50045 mg L(-1), and 156.76666 mg L(-1), respectively. Eight biodegradation products (2-amino-4-chloro-6-methoxypyrimidine, ethyl 2-sulfamoyl benzoate, 2-sulfamoyl benzoic acid, o-benzoic sulfimide, 2-[[(4-chloro-6-methoxy-2-pyrimidinyl) carbamoyl] sulfamoyl] benzoic acid, ethyl 2-carbonyl sulfamoyl benzoate, ethyl 2-benzenesulfonyl isocyanate benzoate, and N,N-2(ethyl formate)benzene sulfonylurea) were identified, and three possible degradation pathways were proposed based on the results of high performance liquid chromatography HPLC, liquid chromatography tandem mass spectroscopy (LC-MS/MS), and Fourier transform infrared spectroscopy (FTIR) analyses and the relevant literature. This systematic study is the first to examine the chlorimuron-ethyl degradation pathways of the genus Rhodococcus. PMID:26810662

  5. An Invertron-Like Linear Plasmid Mediates Intracellular Survival and Virulence in Bovine Isolates of Rhodococcus equi

    PubMed Central

    Valero-Rello, Ana; Hapeshi, Alexia; Anastasi, Elisa; Alvarez, Sonsiray; Scortti, Mariela; Meijer, Wim G.; MacArthur, Iain

    2015-01-01

    We report a novel host-associated virulence plasmid in Rhodococcus equi, pVAPN, carried by bovine isolates of this facultative intracellular pathogenic actinomycete. Surprisingly, pVAPN is a 120-kb invertron-like linear replicon unrelated to the circular virulence plasmids associated with equine (pVAPA) and porcine (pVAPB variant) R. equi isolates. pVAPN is similar to the linear plasmid pNSL1 from Rhodococcus sp. NS1 and harbors six new vap multigene family members (vapN to vapS) in a vap pathogenicity locus presumably acquired via en bloc mobilization from a direct predecessor of equine pVAPA. Loss of pVAPN rendered R. equi avirulent in macrophages and mice. Mating experiments using an in vivo transconjugant selection strategy demonstrated that pVAPN transfer is sufficient to confer virulence to a plasmid-cured R. equi recipient. Phylogenetic analyses assigned the vap multigene family complement from pVAPN, pVAPA, and pVAPB to seven monophyletic clades, each containing plasmid type-specific allelic variants of a precursor vap gene carried by the nearest vap island ancestor. Deletion of vapN, the predicted “bovine-type” allelic counterpart of vapA, essential for virulence in pVAPA, abrogated pVAPN-mediated intramacrophage proliferation and virulence in mice. Our findings support a model in which R. equi virulence is conferred by host-adapted plasmids. Their central role is mediating intracellular proliferation in macrophages, promoted by a key vap determinant present in the common ancestor of the plasmid-specific vap islands, with host tropism as a secondary trait selected during coevolution with specific animal species. PMID:25895973

  6. Biodegradation of variable-chain-length n-alkanes in Rhodococcus opacus R7 and the involvement of an alkane hydroxylase system in the metabolism

    PubMed Central

    2014-01-01

    Rhodococcus opacus R7 is a Gram-positive bacterium isolated from a polycyclic aromatic hydrocarbon contaminated soil for its versatile metabolism; indeed the strain is able to grow on naphthalene, o-xylene, and several long- and medium-chain n-alkanes. In this work we determined the degradation of n-alkanes in Rhodococcus opacus R7 in presence of n-dodecane (C12), n-hexadecane (C16), n-eicosane (C20), n-tetracosane (C24) and the metabolic pathway in presence of C12. The consumption rate of C12 was 88%, of C16 was 69%, of C20 was 51% and of C24 it was 78%. The decrement of the degradation rate seems to be correlated to the length of the aliphatic chain of these hydrocarbons. On the basis of the metabolic intermediates determined by the R7 growth on C12, our data indicated that R. opacus R7 metabolizes medium-chain n-alkanes by the primary alcohol formation. This represents a difference in comparison with other Rhodococcus strains, in which a mixture of the two alcohols was observed. By GC-MSD analysis we also identified the monocarboxylic acid, confirming the terminal oxidation. Moreover, the alkB gene cluster from R. opacus R7 was isolated and its involvement in the n-alkane degradation system was investigated by the cloning of this genomic region into a shuttle-vector E. coli-Rhodococcus to evaluate the alkane hydroxylase activity. Our results showed an increased biodegradation of C12 in the recombinant strain R. erythropolis AP (pTipQT1-alkR7) in comparison with the wild type strain R. erythropolis AP. These data supported the involvement of the alkB gene cluster in the n-alkane degradation in the R7 strain. PMID:25401074

  7. Draft Genome Sequence of the Endophytic Strain Rhodococcus kyotonensis KB10, a Potential Biodegrading and Antibacterial Bacterium Isolated from Arabidopsis thaliana

    PubMed Central

    Hong, Chi Eun; Jo, Sung Hee

    2016-01-01

    Rhodococcus kyotonensis KB10 is an endophytic bacterium isolated from Arabidopsis thaliana. The organism showed mild antibacterial activity against the phytopathogen Pseudomonas syringae pv. tomato DC3000. This study reports the genome sequence of R. kyotonensis KB10. This bacterium contains an ectoine biosynthesis gene cluster and has the potential to degrade nitroaromatic compounds. The identified bacterium may be a suitable biocontrol agent and degrader of environmental pollutants. PMID:27389269

  8. Draft Genome Sequence of the Endophytic Strain Rhodococcus kyotonensis KB10, a Potential Biodegrading and Antibacterial Bacterium Isolated from Arabidopsis thaliana.

    PubMed

    Hong, Chi Eun; Jo, Sung Hee; Jeong, Haeyoung; Park, Jeong Mee

    2016-01-01

    Rhodococcus kyotonensis KB10 is an endophytic bacterium isolated from Arabidopsis thaliana The organism showed mild antibacterial activity against the phytopathogen Pseudomonas syringae pv. tomato DC3000. This study reports the genome sequence of R. kyotonensis KB10. This bacterium contains an ectoine biosynthesis gene cluster and has the potential to degrade nitroaromatic compounds. The identified bacterium may be a suitable biocontrol agent and degrader of environmental pollutants. PMID:27389269

  9. Identification of Clinically Relevant Corynebacterium spp., Arcanobacterium haemolyticum, and Rhodococcus equi by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

    PubMed Central

    Juiz, Pedro; Salas, Carlos; Almela, Manel; de la Fuente, Celia García; Zboromyrska, Yuliya; Navas, Jesús; Bosch, Jordi; Agüero, Jesús; de la Bellacasa, Jorge Puig; Martínez-Martínez, Luis

    2012-01-01

    The identification of 83 Corynebacterium, 13 Arcanobacterium haemolyticum, and 10 Rhodococcus equi strains by conventional methods (API Coryne complemented with 16S rRNA gene sequence analysis) was compared with matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry identification. The correlation between API and MALDI-TOF results was 89%. MALDI-TOF is a rapid and accurate system for identification of the above-mentioned microorganisms. PMID:22337985

  10. Enantioselective Metabolism of Chiral 3-Phenylbutyric Acid, an Intermediate of Linear Alkylbenzene Degradation, by Rhodococcus rhodochrous PB1

    PubMed Central

    Simoni, S.; Klinke, S.; Zipper, C.; Angst, W.; Kohler, H. E.

    1996-01-01

    Rhodococcus rhodochrous PB1 was isolated from compost soil by selective culture with racemic 3-phenylbutyric acid as the sole carbon and energy source. Growth experiments with the single pure enantiomers as well as with the racemate showed that only one of the two enantiomers, (R)-3-phenylbutyric acid, supported growth of strain PB1. Nevertheless, (S)-3-phenylbutyric acid was cometabolically transformed to, presumably, (S)-3-(2,3-dihydroxyphenyl)butyric acid (the absolute configuration at the C-3 atom is not known yet) by (R)-3-phenylbutyric acid-grown cells of strain PB1, as shown by (sup1)H nuclear magnetic resonance spectroscopy of the partially purified compound and gas chromatography-mass spectrometry analysis of the trimethylsilyl derivative. Oxygen uptake rates suggest that either 3-phenylpropionic acid or cinnamic acid (trans-3-phenyl-2-propenoic acid) is the substrate for aromatic ring hydroxylation. This view is substantiated by the fact that 3-(2,3-dihydroxyphenyl)propionic acid was a substrate for meta cleavage in cell extracts of (R)-3-phenylbutyric acid-grown cells of strain PB1. Gas chromatography-mass spectrometry analysis of trimethylsilane-treated ethyl acetate extracts of incubation mixtures showed that both the meta-cleavage product, 2-hydroxy-6-oxo-2,4-nonadiene-1,9-dicarboxylic acid, and succinate, a hydrolysis product thereof, were formed during such incubations. PMID:16535265

  11. Selective cleavage of the two CS bonds in asymmetrically alkylated dibenzothiophenes by Rhodococcus erythropolis KA2-5-1.

    PubMed

    Onaka, T; Kobayashi, M; Ishii, Y; Konishi, J; Maruhashi, K

    2001-01-01

    The Rhodococcus erythropolis strain KA2-5-1 was characterized by its ability to cleave carbon-sulfur bonds in the dibenzothiophene (DBT) ring by asymmetrically alkyl substitution, such as C2-DBTs (e.g., dimethyl and ethyl DBTs) and C3-DBTs (e.g., trimethyl and propyl DBTs), which are known to remain in hydrodesulfurization-treated diesel fuels. After treatment by solid-phase extraction (SPE) of solvents from microbial reactions of alkylated DBTs (Cx-DBTs), we used gas chromatography (GC), GC-atomic emission detection, GC-mass spectrometry and 1H nuclear magnetic resonance spectroscopy to identify and quantitatively evaluate the Cx-DBT metabolites. Molar ratios of metabolic isomers of the desulfurization products suggested that resting-cell reactions of KA2-5-1 against these Cx-DBTs occurrs through specific carbon-sulfur-bond-targeted cleavages, yielding alkylated hydroxybiphenyls, and that the manner of the attack on the DBT skeleton is affected not only by the position but also by the number and length of the alkyl substituents. PMID:16233063

  12. Genetic and Biochemical Characterization of a Novel Monoterpene ɛ-Lactone Hydrolase from Rhodococcus erythropolis DCL14

    PubMed Central

    van der Vlugt-Bergmans, Cécile J. B; van der Werf, Mariët J.

    2001-01-01

    A monoterpene ɛ-lactone hydrolase (MLH) from Rhodococcus erythropolis DCL14, catalyzing the ring opening of lactones which are formed during degradation of several monocyclic monoterpenes, including carvone and menthol, was purified to apparent homogeneity. It is a monomeric enzyme of 31 kDa that is active with (4R)-4-isopropenyl-7-methyl-2-oxo-oxepanone and (6R)-6-isopropenyl-3-methyl-2-oxo-oxepanone, lactones derived from (4R)-dihydrocarvone, and 7-isopropyl-4-methyl-2-oxo-oxepanone, the lactone derived from menthone. Both enantiomers of 4-, 5-, 6-, and 7-methyl-2-oxo-oxepanone were converted at equal rates, suggesting that the enzyme is not stereoselective. Maximal enzyme activity was measured at pH 9.5 and 30°C. Determination of the N-terminal amino acid sequence of purified MLH enabled cloning of the corresponding gene by a combination of PCR and colony screening. The gene, designated mlhB (monoterpene lactone hydrolysis), showed up to 43% similarity to members of the GDXG family of lipolytic enzymes. Sequencing of the adjacent regions revealed two other open reading frames, one encoding a protein with similarity to the short-chain dehydrogenase reductase family and the second encoding a protein with similarity to acyl coenzyme A dehydrogenases. Both enzymes are possibly also involved in the monoterpene degradation pathways of this microorganism. PMID:11157238

  13. The Equine Antimicrobial Peptide eCATH1 Is Effective against the Facultative Intracellular Pathogen Rhodococcus equi in Mice

    PubMed Central

    Schlusselhuber, Margot; Torelli, Riccardo; Martini, Cecilia; Leippe, Matthias; Cattoir, Vincent; Leclercq, Roland; Laugier, Claire; Grötzinger, Joachim; Sanguinetti, Maurizio

    2013-01-01

    Rhodococcus equi, the causal agent of rhodococcosis, is a major pathogen of foals and is also responsible for severe infections in immunocompromised humans. Of great concern, strains resistant to currently used antibiotics have emerged. As the number of drugs that are efficient in vivo is limited because of the intracellular localization of the bacterium inside macrophages, new active but cell-permeant drugs will be needed in the near future. In the present study, we evaluated, by in vitro and ex vivo experiments, the ability of the alpha-helical equine antimicrobial peptide eCATH1 to kill intracellular bacterial cells. Moreover, the therapeutic potential of the peptide was assessed in experimental rhodococcosis induced in mice, while the in vivo toxicity was evaluated by behavioral and histopathological analysis. The study revealed that eCATH1 significantly reduced the number of bacteria inside macrophages. Furthermore, the bactericidal potential of the peptide was maintained in vivo at doses that appeared to have no visible deleterious effects for the mice even after 7 days of treatment. Indeed, daily subcutaneous injections of 1 mg/kg body weight of eCATH1 led to a significant reduction of the bacterial load in organs comparable to that obtained after treatment with 10 mg/kg body weight of rifampin. Interestingly, the combination of the peptide with rifampin showed a synergistic interaction in both ex vivo and in vivo experiments. These results emphasize the therapeutic potential that eCATH1 represents in the treatment of rhodococcosis. PMID:23817377

  14. Comparison of tulathromycin, azithromycin and azithromycin-rifampin for the treatment of mild pneumonia associated with Rhodococcus equi.

    PubMed

    Venner, M; Credner, N; Lämmer, M; Giguère, S

    2013-10-26

    The objectives of the present study were to determine the relative efficacy of tulathromycin, azithromycin, or azithromycin with rifampin for the treatment of pulmonary abscesses on a farm with endemic infections caused by Rhodococcus equi. Foals with ultrasonographic evidence of pulmonary abscesses (abscess score 8.0-15 cm; n=120) were randomly allocated in four equal treatment groups: (1) tulathromycin intramuscularly; (2) azithromycin monotherapy, orally; (3) azithromycin with rifampin, orally; (4) saline intramuscularly as a placebo. Physical examination and thoracic ultrasonography were performed by individuals unaware of treatment group assignment. Foals that worsened were removed from the study. The proportion of foals that recovered without the need for a change in therapy was significantly higher for foals treated with azithromycin (29 of 30) or azithromycin with rifampin (28 of 30) than for foals treated with a placebo (20 of 30). Additionally, azithromycin or azithromycin with rifampin resulted in a significantly faster decrease in the number of abscesses and abscess score compared with a placebo. The proportion of foals treated with tulathromycin that recovered (27 of 30) was not significantly different from that of foals treated with a placebo. Azithromycin alone or in combination with rifampin was beneficial in the study population. PMID:24106244

  15. Evaluation of biosurfactants grown in corn oil by Rhodococcus rhodochrous on removing of heavy metal ion from aqueous solution

    NASA Astrophysics Data System (ADS)

    Suryanti, Venty; Hastuti, Sri; Pujiastuti, Dwi

    2016-02-01

    The potential application of biosurfactants to remove heavy metal ion from aqueous solution by batch technique was examined. The glycolipids type biosurfactants were grown in a media containing of 20% v/v corn oil with 7 days of fermentation by Rhodococcus rhodochrous. The biosurfactants reduced the surface tension of water of about 51% from 62 mN/m to 30 mN/m. The biosurfactant increased the E24 of water-palm oil emulsion of about 55% from 43% to 97% and could maintain this E24 value of above 50% for up to 9 days. Heavy metal ion removal, in this case cadmium ion, by crude and patially purified biosurfactants has been investigated from aqueous solution at pH 6. Adsorption capacity of Cd(II) ion by crude biosurfactant with 5 and 10 minutes of contact times were 1.74 and 1.82 mg/g, respectively. Additionally, the adsorption capacity of Cd(II) ion by partially purified biosurfactant with 5 and 10 minutes of contact times were 0.79 and 1.34 mg/g, respectively. The results demonstrated that the adsorption capacity of Cd(II) ion by crude biosurfactant was higher than that of by partially purified biosurfactant. The results suggested that the biosurfactant could be used in the removal of heavy metal ions from aqueous solution.

  16. Regulation of plasmid-encoded isoprene metabolism in Rhodococcus, a representative of an important link in the global isoprene cycle.

    PubMed

    Crombie, Andrew T; Khawand, Myriam El; Rhodius, Virgil A; Fengler, Kevin A; Miller, Michael C; Whited, Gregg M; McGenity, Terry J; Murrell, J Colin

    2015-09-01

    Emissions of biogenic volatile organic compounds (VOCs) form an important part of the global carbon cycle, comprising a significant proportion of net ecosystem productivity. They impact atmospheric chemistry and contribute directly and indirectly to greenhouse gases. Isoprene, emitted largely from plants, comprises one third of total VOCs, yet in contrast to methane, which is released in similar quantities, we know little of its biodegradation. Here, we report the genome of an isoprene degrading isolate, Rhodococcus sp. AD45, and, using mutagenesis shows that a plasmid-encoded soluble di-iron centre isoprene monooxygenase (IsoMO) is essential for isoprene metabolism. Using RNA sequencing (RNAseq) to analyse cells exposed to isoprene or epoxyisoprene in a substrate-switch time-course experiment, we show that transcripts from 22 contiguous genes, including those encoding IsoMO, were highly upregulated, becoming among the most abundant in the cell and comprising over 25% of the entire transcriptome. Analysis of gene transcription in the wild type and an IsoMO-disrupted mutant strain showed that epoxyisoprene, or a subsequent product of isoprene metabolism, rather than isoprene itself, was the inducing molecule. We provide a foundation of molecular data for future research on the environmental biological consumption of this important, climate-active compound. PMID:25727256

  17. Functional characterization and stability improvement of a ‘thermophilic-like’ ene-reductase from Rhodococcus opacus 1CP

    PubMed Central

    Riedel, Anika; Mehnert, Marika; Paul, Caroline E.; Westphal, Adrie H.; van Berkel, Willem J. H.; Tischler, Dirk

    2015-01-01

    Ene-reductases (ERs) are widely applied for the asymmetric synthesis of relevant industrial chemicals. A novel ER OYERo2 was found within a set of 14 putative old yellow enzymes (OYEs) obtained by genome mining of the actinobacterium Rhodococcus opacus 1CP. Multiple sequence alignment suggested that the enzyme belongs to the group of ‘thermophilic-like’ OYEs. OYERo2 was produced in Escherichia coli and biochemically characterized. The enzyme is strongly NADPH dependent and uses non-covalently bound FMNH2 for the reduction of activated α,β-unsaturated alkenes. In the active form OYERo2 is a dimer. Optimal catalysis occurs at pH 7.3 and 37°C. OYERo2 showed highest specific activities (45-50 U mg-1) on maleimides, which are efficiently converted to the corresponding succinimides. The OYERo2-mediated reduction of prochiral alkenes afforded the (R)-products with excellent optical purity (ee > 99%). OYERo2 is not as thermo-resistant as related OYEs. Introduction of a characteristic intermolecular salt bridge by site-specific mutagenesis raised the half-life of enzyme inactivation at 32°C from 28 to 87 min and improved the tolerance toward organic co-solvents. The suitability of OYERo2 for application in industrial biocatalysis is discussed. PMID:26483784

  18. Degradation of recalcitrant aliphatic and aromatic hydrocarbons by a dioxin-degrader Rhodococcus sp. strain p52.

    PubMed

    Yang, Hai-Yan; Jia, Rui-Bao; Chen, Bin; Li, Li

    2014-09-01

    This study investigates the ability of Rhodococcus sp. strain p52, a dioxin degrader, to biodegrade petroleum hydrocarbons. Strain p52 can use linear alkanes (tetradecane, tetracosane, and dotriacontane), branched alkane (pristane), and aromatic hydrocarbons (naphthalene and phenanthrene) as sole carbon and energy sources. Specifically, the strain removes 85.7 % of tetradecane within 48 h at a degradation rate of 3.8 mg h(-1) g(-1) dry cells, and 79.4 % of tetracosane, 66.4 % of dotriacontane, and 63.9 % of pristane within 9-11 days at degradation rates of 20.5, 14.7, and 20.3 mg day(-1) g(-1) dry cells, respectively. Moreover, strain p52 consumes 100 % naphthalene and 55.3 % phenanthrene within 9-11 days at respective degradation rates of 16 and 12.9 mg day(-1) g(-1) dry cells. Metabolites of the petroleum hydrocarbons by strain p52 were analyzed. Genes encoding alkane-hydroxylating enzymes, including cytochrome P450 (CYP450) enzyme (CYP185) and two alkane-1-monooxygenases, were amplified by polymerase chain reaction. The transcriptional activities of these genes in the presence of petroleum hydrocarbons were detected by reverse transcription-polymerase chain reaction. The results revealed potential of strain p52 to degrade petroleum hydrocarbons. PMID:24859700

  19. Rhodococcus equi--an emerging human pathogen in immunocompromized hosts: a report of four cases from Malaysia.

    PubMed

    Puthucheary, S D; Sangkar, V; Hafeez, Asma; Karunakaran, R; Raja, Nadeem S; Hassan, H H

    2006-01-01

    Rhodococcus equi, a recognized pathogen in horses, is emerging as a human opportunistic pathogen, especially in immunocompromized hosts. We describe four immunocompromized patients who had serious R. equi infections with an overall mortality of 75%. The natural habitat of R. equi is soil, particularly soil contaminated with animal manure. Necrotizing pneumonia is the commonest form of infection but extrapulmonary infections, such as wound infections and subcutaneous abscess, have also been described in humans. R. equi is cultured easily in ordinary non-selective media. Large, smooth, irregular colonies appear within 48 hours. It is a facultative, intracellular, nonmotile, non-spore forming, gram-positive coccobacillus, which is weakly acid-fast staining and bears a similarity to diphtheroids. It forms a salmon-colored pigment usually after 48 hours incubation. A particular characteristic of this organism is that it undergoes synergistic hemolysis with some bacteria on sheep blood agar. R. equi may be misidentified as diphtheroids, Mycobacterium species, or Nocardia. In vitro R. equi is usually susceptible to erythromycin, ciprofloxacin, vancomycin, aminoglycosides, rifampin, imipenem and meropenem. The organism can be difficult to eradicate, making treatment challenging. Increased awareness of the infection may help with early diagnosis and timely treatment. PMID:16771229

  20. A nucleotide mutation associated with fluoroquinolone resistance observed in gyrA of in vitro obtained Rhodococcus equi mutants.

    PubMed

    Niwa, Hidekazu; Hobo, Seiji; Anzai, Toru

    2006-06-15

    In this study, the quinolone resistance-determining region (QRDR) in gyrA and gyrB of in vitro fluoroquinolone-resistant Rhodococcus equi mutants was sequenced. These mutants were selected from four R. equi strains on blood agar plates containing ciprofloxacin or enrofloxacin. Each mutant became 8- to 64 or greater-fold resistant to fluoroquinolones compared with their parent strains. From the results of sequence analysis of QRDR in gyrA and gyrB, a nucleotide mutation of codon GAC for GGC in gyrA was detected in all mutants, but no mutation was observed in gyrB. This mutation leads to amino acid substitution of Asp for Gly in putative GyrA in R. equi. The position of this substitution corresponds to position 87 of GyrA in Escherichia coli. Our results suggest that the mutation of QRDR in gyrA, which was observed in in vitro fluoroquinolone-resistant R. equi mutants in this study, is closely associated with fluoroquinolone resistance. PMID:16563665

  1. Biocatalytic Properties and Structural Analysis of Eugenol Oxidase from Rhodococcus jostii RHA1: A Versatile Oxidative Biocatalyst.

    PubMed

    Nguyen, Quoc-Thai; de Gonzalo, Gonzalo; Binda, Claudia; Rioz-Martínez, Ana; Mattevi, Andrea; Fraaije, Marco W

    2016-07-15

    Eugenol oxidase (EUGO) from Rhodococcus jostii RHA1 had previously been shown to convert only a limited set of phenolic compounds. In this study, we have explored the biocatalytic potential of this flavoprotein oxidase, resulting in a broadened substrate scope and a deeper insight into its structural properties. In addition to the oxidation of vanillyl alcohol and the hydroxylation of eugenol, EUGO can efficiently catalyze the dehydrogenation of various phenolic ketones and the selective oxidation of a racemic secondary alcohol-4-(1-hydroxyethyl)-2-methoxyphenol. EUGO was also found to perform the kinetic resolution of a racemic secondary alcohol. Crystal structures of the enzyme in complexes with isoeugenol, coniferyl alcohol, vanillin, and benzoate have been determined. The catalytic center is a remarkable solvent-inaccessible cavity on the si side of the flavin cofactor. Structural comparison with vanillyl alcohol oxidase from Penicillium simplicissimum highlights a few localized changes that correlate with the selectivity of EUGO for phenolic substrates bearing relatively small p-substituents while tolerating o-methoxy substituents. PMID:27123962

  2. Simple Preparation of Rhodococcus erythropolis DSM 44534 as Biocatalyst to Oxidize Diols into the Optically Active Lactones.

    PubMed

    Martinez-Rojas, Enriqueta; Olejniczak, Teresa; Neumann, Konrad; Garbe, Leif-Alexander; Boratyñski, Filip

    2016-09-01

    In the current study, we present a green toolbox to produce ecological compounds like lactone moiety. Rhodococcus erythropolis DSM 44534 cells have been used to oxidize both decane-1,4-diol () and decane-1,5-diol () into the corresponding γ- () and δ-decalactones () with yield of 80% and enantiomeric excess (ee) = 75% and ee = 90%, respectively. Among oxidation of meso diols, (-)-(1S,5R)-cis-3-oxabicyclo[4.3.0]non-7-en-2-one (5a) with 56% yield and ee = 76% as well as (-)-(2R,3S)-cis-endo-3-oxabicyclo[2.2.1]dec-7-en-2-one (6a) with 100% yield and ee = 90% were formed. It is worth mentioning that R. erythropolis DSM 44534 grew in a mineral medium containing ethanol as the sole source of energy and carbon Chirality 28:623-627, 2016. © 2016 Wiley Periodicals, Inc. PMID:27496202

  3. Modulation of the Hormone Setting by Rhodococcus fascians Results in Ectopic KNOX Activation in Arabidopsis1[W][OA

    PubMed Central

    Depuydt, Stephen; Doležal, Karel; Van Lijsebettens, Mieke; Moritz, Thomas; Holsters, Marcelle; Vereecke, Danny

    2008-01-01

    The biotrophic actinomycete Rhodococcus fascians has a profound impact on plant development and a common aspect of the symptomatology is the deformation of infected leaves. In Arabidopsis (Arabidopsis thaliana), the serrated leaf margins formed upon infection resemble the leaf phenotype of transgenic plants with ectopic expression of KNOTTED-like homeobox (KNOX) genes. Through transcript profiling, we demonstrate that class-I KNOX genes are transcribed in symptomatic leaves. Functional analysis revealed that BREVIPEDICELLUS/KNOTTED-LIKE1 and mainly SHOOT MERISTEMLESS were essential for the observed leaf dissection. However, these results also positioned the KNOX genes downstream in the signaling cascade triggered by R. fascians infection. The much faster activation of ARABIDOPSIS RESPONSE REGULATOR5 and the establishment of homeostatic and feedback mechanisms to control cytokinin (CK) levels support the overrepresentation of this hormone in infected plants due to the secretion by the pathogen, thereby placing the CK response high up in the cascade. Hormone measurements show a net decrease of tested CKs, indicating either that secretion by the bacterium and degradation by the plant are in balance, or, as suggested by the strong reaction of 35S:CKX plants, that other CKs are at play. At early time points of the interaction, activation of gibberellin 2-oxidase presumably installs a local hormonal setting favorable for meristematic activity that provokes leaf serrations. The results are discussed in the context of symptom development, evasion of plant defense, and the establishment of a specific niche by R. fascians. PMID:18184732

  4. Rhodococcus equi virulence-associated protein A is required for diversion of phagosome biogenesis but not for cytotoxicity.

    PubMed

    von Bargen, Kristine; Polidori, Marco; Becken, Ulrike; Huth, Gitta; Prescott, John F; Haas, Albert

    2009-12-01

    Rhodococcus equi is a gram-positive facultative intracellular pathogen that can cause severe bronchopneumonia in foals and AIDS patients. Virulence is plasmid regulated and is accompanied by phagosome maturation arrest and host cell necrosis. A replacement mutant in the gene for VapA (virulence-associated protein A), a major virulence factor of R. equi, was tested for its activities during macrophage infection. Early in infection, phagosomes containing the vapA mutant did not fuse with lysosomes and did not stain with the acidotropic fluor LysoTracker similar to those containing virulent wild-type R. equi. However, vapA mutant phagosomes had a lower average pH. Late in infection, phagosomes containing the vapA mutant were as frequently positive for LysoTracker as phagosomes containing plasmid-cured, avirulent bacteria, whereas those with virulent wild-type R. equi were still negative for the fluor. Macrophage necrosis after prolonged infection with virulent bacteria was accompanied by a loss of organelle staining with LysoTracker, suggesting that lysosome proton gradients had collapsed. The vapA mutant still killed the macrophages and yet did not affect the pH of host cell lysosomes. Hence, VapA is not required for host cell necrosis but is required for neutralization of phagosomes and lysosomes or their disruption. This is the first report of an R. equi mutant with altered phagosome biogenesis. PMID:19797071

  5. Serum antibody responses of foals to virulence-associated 15- to 17-kilodalton antigens of Rhodococcus equi.

    PubMed

    Tákai, S; Hidaka, D; Fujii, M; Shindoh, Y; Murata, T; Nakanishi, S; Sasaki, Y; Tsubaki, S; Kamada, M

    1996-09-01

    Humoral immune responses in 16 foals to virulence-associated 15- to 17-kDa antigens of Rhodococcus equi were studied during the first fourteen weeks of life on two horse-breeding farms with a persistent incidence of R. equi infection. Serum antibody levels specific for 15- to 17-kDa antigens were measured by enzyme-linked immunosorbent assay and Western immunoblotting. Immunoglobulin G (IgG) antibodies specific to 15- to 17-kDa antigens were detected by all the foals. R. equi was found in the feces of foals during week 1 of life, and the number of fecal R. equi rapidly increased to the highest level. Virulent R. equi were isolated from the feces of the foals at a high frequency and from their environmental soil on the farms. Evidence that serum antibody response to 15- to 17-kDa antigens of virulent R. equi occurred naturally in every foal in correlation with the quantitative changes of fecal R. equi during the first 1 to 3 months of life suggests that intestinal virulent R. equi might be the most important source of antigenic stimulation in foals from contaminated farms. PMID:8914251

  6. Optimization of biosurfactant production in soybean oil by rhodococcus rhodochrous and its utilization in remediation of cadmium-contaminated solution

    NASA Astrophysics Data System (ADS)

    Suryanti, Venty; Hastuti, Sri; Andriani, Dewi

    2016-02-01

    Biosurfactant production by Rhodococcus rhodochrous in soybean oil was developed, where the effect of medium composition and fermentation time were evaluated. The optimum condition for biosurfactant production was achieved when a medium containing 30 g/L TSB (tryptic soy broth) and 20% v/v soybean oil was used as media with 7 days of fermentation. Biosurfactant was identified as glycolipids type biosurfactant which had critical micelle concentration (CMC) value of 896 mg/L. The biosurfactant had oil in water emulsion type and was able to reduce the surface tension of palm oil about 52% which could stabilize the emulsion up to 12 days. The batch removal of cadmium metal ion by crude and partially purified biosurfactants have been examined from synthetic aqueous solution at pH 6. The results exhibited that the crude biosurfactant had a much better adsorption ability of Cd(II) than that of partially purified biosurfactant. However, it was found that there was no significant difference in the adsorption of Cd(II) with 5 and 10 minutes of contact time. The results indicated that the biosurfactant could be used in remediation of heavy metals from contaminated aqueous solution.

  7. High-cell-density batch fermentation of Rhodococcus opacus PD630 using a high glucose concentration for triacylglycerol production.

    PubMed

    Kurosawa, Kazuhiko; Boccazzi, Paolo; de Almeida, Naomi M; Sinskey, Anthony J

    2010-06-01

    Biodiesel, monoalkyl esters of long-chain fatty acids with short-chain alcohols derived from triacylglycerols (TAGs), can be produced from renewable biomass sources. Recently, there has been interest in producing microbial oils from oleaginous microorganisms. Rhodococcus opacus PD630 is known to accumulate large amounts of TAGs. Following on these earlier works we demonstrate that R. opacus PD630 has the uncommon capacity to grow in defined media supplemented with glucose at a concentration of 300 g l(-1) during batch-culture fermentations. We found that we could significantly increase concentrations of both glucose and (NH4)2SO4 in the production medium resulting in a dramatic increase in fatty acid production when pH was controlled. We describe the experimental design protocol used to achieve the culture conditions necessary to obtain both high-cell-density and TAG accumulation; specifically, we describe the importance of the C/N ratio of the medium composition. Our bioprocess results demonstrate that R. opacus PD630 grown in batch-culture with an optimal production medium containing 240 g l(-1) glucose and 13.45 g l(-1) (NH4)2SO4 (C/N of 17.8) yields 77.6 g l(-1) of cell dry weight composed of approximately 38% TAGs indicating that this strain holds great potential as a future source of industrial biodiesel on starchy cellulosic feedstocks that are glucose polymers. PMID:20412824

  8. Identification of pathogens and virulence profile of Rhodococcus equi and Escherichia coli strains obtained from sand of parks

    PubMed Central

    Fernandes, M.C.; Takai, S.; Leite, D.S.; Pinto, J.P.A.N.; Brandão, P.E.; Santarém, V.A.; Listoni, F.J.P.; Da Silva, A.V.; Ribeiro, M.G.

    2013-01-01

    The identification of pathogens of viral (Rotavirus, Coronavirus), parasitic (Toxocara spp.) and bacterial (Escherichia coli, Salmonella spp., Rhodococcus equi) origin shed in feces, and the virulence profile of R. equi and E. coli isolates were investigated in 200 samples of sand obtained from 40 parks, located in central region of state of Sao Paulo, Brazil, using different diagnostic methods. From 200 samples analyzed, 23 (11.5%) strains of R. equi were isolated. None of the R. equi isolates showed a virulent (vapA gene) or intermediately virulent (vapB gene) profiles. Sixty-three (31.5%) strains of E. coli were identified. The following genes encoding virulence factors were identified in E. coli: eae, bfp, saa, iucD, papGI, sfa and hly. Phylogenetic classification showed that 63 E. coli isolates belonged to groups B1 (52.4%), A (25.4%) and B2 (22.2%). No E. coli serotype O157:H7 was identified. Eggs of Toxocara sp. were found in three parks and genetic material of bovine Coronavirus was identified in one sample of one park. No Salmonella spp. and Rotavirus isolates were identified in the samples of sand. The presence of R. equi, Toxocara sp, bovine Coronavirus and virulent E. coli isolates in the environment of parks indicates that the sanitary conditions of the sand should be improved in order to reduce the risks of fecal transmission of pathogens of zoonotic potential to humans in these places. PMID:24294244

  9. Adaptive response of Rhodococcus opacus PWD4 to salt and phenolic stress on the level of mycolic acids.

    PubMed

    de Carvalho, Carla C C R; Fischer, Martin A; Kirsten, Sandra; Würz, Birgit; Wick, Lukas Y; Heipieper, Hermann J

    2016-12-01

    Mycolata form a group of Gram-positive bacteria with unique cell envelope structures that are known for their high tolerance against antibiotics and both aromatic and aliphatic hydrocarbons. An important part of the unique surface structure of the mycolata is the presence of long chain α-alkyl-β-hydroxy fatty acids, the mycolic acids. In order to investigate the adaptive changes in the mycolic acid composition, we investigated the composition of mycolic acids during the response both to osmotic stress caused by NaCl and to 4-chlorophenol in Rhodococcus opacus PWD4. This bacterium was chosen as it is known to adapt to different kinds of stresses. In addition, it is a potential biocatalyst in bioremediation as well as for biotechnological applications. In the present study, cells of R. opacus PWD4, grown in liquid cultures, responded to toxic concentrations of NaCl by increasing the ratio between mycolic acids and membrane phospholipid fatty acids (MA/PLFA-ratio). Cells reacted to both NaCl and 4-chlorophenol by decreasing both the average chain length and the unsaturation index of their mycolic acids. These changes in mycolic acid composition correlated with increases in cell surface hydrophobicity and saturation of membrane fatty acids, demonstrating the relation between mycolic acid and phospholipid synthesis and their contribution to cell surface properties of R. opacus PWD4. PMID:27620730

  10. Electrical resistivity tomography to monitor enhanced biodegradation of hydrocarbons with Rhodococcus erythropolis T902.1 at a pilot scale

    NASA Astrophysics Data System (ADS)

    Masy, Thibaut; Caterina, David; Tromme, Olivier; Lavigne, Benoît; Thonart, Philippe; Hiligsmann, Serge; Nguyen, Frédéric

    2016-01-01

    Petroleum hydrocarbons (HC) represent the most widespread contaminants and in-situ bioremediation remains a competitive treatment in terms of cost and environmental concerns. However, the efficiency of such a technique (by biostimulation or bioaugmentation) strongly depends on the environment affected and is still difficult to predict a priori. In order to overcome these uncertainties, Electrical Resistivity Tomography (ERT) appears as a valuable non-invasive tool to detect soil heterogeneities and to monitor biodegradation. The main objective of this study was to isolate an electrical signal linked to an enhanced bacterial activity with ERT, in an aged HC-contaminated clay loam soil. To achieve this, a pilot tank was built to mimic field conditions. Compared to a first insufficient biostimulation phase, bioaugmentation with Rhodococcus erythropolis T902.1 led to a HC depletion of almost 80% (6900 to 1600 ppm) in 3 months in the center of the contaminated zone, where pollutants were less bioavailable. In the meantime, lithological heterogeneities and microbial activities (growth and biosurfactant production) were successively discriminated by ERT images. In the future, this cost-effective technique should be more and more transferred to the field in order to monitor biodegradation processes and assist in selecting the most appropriate remediation technique.