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PubMed1997

Site-specific endonucleases RspLKI and RspLKII from Rhodococcus species LK2 are isoschizomers of SphI and BamHI.

Two site-specific endonucleases, RspLKI and RspLKII, have been isolated and purified to functional homogeneity from the soil bacterium Rhodococcus species LK2. RspLKI recognizes the 5'-GCATG decreases C-3' DNA sequence and RspLKII recognizes the 5'-G decreases GATCC-3' sequence (arrows indicate DNA cleavage sites). The isolated enzymes are class II site specific endonucleases and are isoschizomers of endonucleases SphI and BamHI, respectively.

Chromatography, Ion Exchange↗
PubMed1985

Menaquinone composition of mycolic acid-containing actinomycetes and some sporoactinomycetes.

The menaquinones of 141 actinomycetes representing the genera Caseobacter, Mycobacterium, Nocardia, Rhodococcus and some related taxa lacking mycolic acids were examined by mass spectrometry. The mycolic acid-containing strains were assigned to four groups on the basis of the predominant isoprenologue detected: Rhodococcus coprophilus, R. equi, R. erythropolis, R. globerulus, R. rhodnii, R. rhodochrous and R. ruber contained dihydrogenated menaquinones with eight isoprene units; Nocardia asteroides, N. brasiliensis, N. carnea, N. otitidis-caviarum and N. transvalensis contained tetrahydrogenated menaquinones with eight isoprene units; Caseobacter polymorphus, R. bronchialis, R. rubropertinctus and R. terrae and representatives of twenty-one approved species of Mycobacterium contained dihydrogenated menaquinones with nine isoprene units; a single strain of 'Mycobacterium album', contained unsaturated menaquinones with nine isoprene units. Actinomycetes containing meso-diaminopimelic acid, arabinose and galactose in the wall peptidoglycan but lacking mycolic acids were recovered in two groups: tetrahydrogenated menaquinones with eight isoprene units were the main components from 'Nocardia' autotrophica and Pseudonocardia thermophila whereas Saccharopolyspora hirsuta and Pseudonocardia spp. contained tetrahydrogenated menaquinones with nine isoprene units. Promicromonospora citrea and 'skin coryneforms' with LL-diaminopimelic acid and glycine in the wall peptidoglycan also contained tetrahydrogenated menaquinones with nine isoprene units as the major isoprenologue. In contrast, representatives of the genera Kitasatoa, Microellobosporia, Streptomyces and Streptoverticillium were characterized by the presence of complex mixtures of tetra-, hexa- and octa-hydrogenated menaquinones with nine isoprene units. The menaquinone data correlate well with other developments in actinomycete systematics and confirm earlier suggestions that menaquinone analyses are of value in both the classification and identification of actinomycetes. Indeed, the data suggest that minimal descriptions of wall chemotype IV taxa should ideally include information on menaquinone composition.

Actinomycetales↗
PubMed1983

Fine structural studies of Rhodococcus species.

Fine structural aspects of Rhodococcus rhodochrous and R. equi are described and illustrated by electron micrographs after staining of cells by a variety of electron cytochemical procedures. The cell contents of these actinomycetous bacteria were those of a typical prokaryotic cell and consistent with that observed for other species of the Actinomycetales. Fixation with either osmium tetroxide or permanganate indicated the presence of an electron opaque substance at the wall exterior of R. rhodochrous which is thought to be composed of protein. Ruthenium red and Alcian blue-lanthanum stains for mucosubstances revealed that both species possess a capsular substance thought to be composed of a mucopolysaccharide or mucopolysaccharide-protein complex. This substance was non-reactive toward the PATAg stain for polysaccharide macromolecules containing vicinal glycol groups.

Cell Membrane↗
PubMed1988

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

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 Rhodococcus sp. strain AS-50, a derivative of strain H13-A, by polyethylene glycol-assisted transformation of Rhodococcus protoplasts and selection for thiostrepton-resistant transformants. Thiostrepton-resistant transformants were also ampicillin resistant and were shown to contain pMVS301, which was subsequently isolated and transformed back into E. coli. 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. Optimization of the transformation procedure resulted in transformation frequencies in the range of 10(5) transformants per micrograms of pMVS301 DNA in Rhodococcus sp. strain H13-A and derivative strains. The plasmid host range extends to strains of Rhodococcus erythropolis, R. globulerus, and R. equi, whereas stable transformants were not obtained with R. rhodochrous or with several coryneform bacteria tested as recipients. 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.

Ampicillin↗
PubMed1988

Differentiation between genera Rhodococcus and Nocardia by susceptibility testing to kanamycin and some other antituberculosis agents.

The test for susceptibility to kanamycin is useful for differentiating between the genera Rhodococcus and Nocardia. All rhodococci except R. equi, R. erythropolis, and R. aurantiacus are susceptible to kanamycin, whereas all nocardiae except N. otitidis-caviarum are resistant to kanamycin. Tests for susceptibility to rifampicin, streptomycin, and minocycline also are useful for differentiating among the species of each genus.

Animals↗
PubMed1977

The actinomycete-genus Rhodococcus: a home for the "rhodochrous" complex.

A numerical taxonomic classification study was carried out on 177 strains representing the "rhodochrous" complex and the genera Gordona, Mycobacterium and Nocardia. The strains were examined for 92 unit characters and the data were analysed by computer. Three clusters were defined at the 75 to 80% similarity level. The first was a heterogeneous cluster corresponding to the "rhodochrous" taxon whereas the other two contained Mycobacterium and Nocardia strains respectively. The good correlation between the numerical analysis and chemo-taxonomic, serological and genetical data collected from previous studies provides sufficient evidence for raising the "rhodochrous" taxon to generic status. We consider the generic name Rhodococcus Aopf to have priority over Proactinomyces (Jensen) Bradley & Bond, Jensenia Bisset & Moore and Gordona Tsukamura. In addition to the type species, Rhodococcus rhodochrous, nine species are recognized: R. bronchialis, R. coprophilus, R. corallinus, R. erythropolis, R. equi, R. rhodnii, R. rubrus, R. rubropertinctus and R. terrae.

Genetics, Microbial↗
PubMed1989

Carotenoid pigments of genus Rhodococcus.

A study of carotenoid pigments of the genus Rhodococcus was carried out. According to carotenes contained, Rhodococcus species were divided into three groups: the first group of Rhodococcus luteus, R. coprophilus, R. lentifragmentus, and R. maris, which formed beta-carotene; the second group of R. equi, R. rubropertinctus, R. aichiensis, R. sputi, R. chubuensis, R. obuensis, R. bronchialis, R. roseus, R. rhodochrous, R. rhodnii, and R. terrae, which formed gamma-carotene-like substance; and the third group of R. aurantiacus, which formed neither carotene. Other carotenoid pigments were different according to the species.

Carotenoids↗
PubMed1986

Distribution and application of mycobactins for the characterization of species within the genus Rhodococcus.

Representatives of 11 species of Rhodococcus were examined for their ability to synthesize mycobactin, a lipid-soluble siderophore, following iron-limited growth on solidified glycerol/asparagine medium. Rhodococcus bronchialis, R. terrae and R. rubropertinctus formed mycobactins, whereas the remaining species (R. coprophilus, R. equi, R. erythropolis, R. rhodnii, R. rhodochrous, R. ruber, R. maris and R. luteus) failed to synthesize these compounds even under conditions of strictly iron-limited growth. The mycobactins from R. terrae and R. rubropertinctus showed close similarity by thin-layer chromatography and high-performance liquid chromatography and could be easily distinguished from that of R. bronchialis.

Actinomycetales↗
PubMedDate not supplied

Cloning of genes that have environmental and clinical importance from rhodococci and related bacteria.

Generalised and specialised transduction systems were developed for Rhodococcus by means of bacteriophage Q4. The latter was used in conjunction with DNA from an unstable genetic element of R. rhodochrous to construct resistance plasmids which replicate in strains of R. equi, R. erythropolis and R. rhodochrous. One of the plasmids, pDA21, was joined with Erythropolis coli suicide vector pEcoR251 to obtain shuttle plasmids maintained in both rhodococci and E. coli. Conjugation between these rhodococcal strains demonstrated all were interfertile with each other and that some of the determinants for this were located on the unstable genetic element. Plasmids derived from this element, such as pDA21, carried the conjugative and self-incompatibility capacities; deletion analysis revealed that DNA necessary for self-incompatibility overlapped with that for arsenic resistance. Rifampicin is one of the principal chemotherapeutic agents used to treat infections by rhodococci and related organisms. The genes responsible for two types of inactivation have been cloned. The sequence of the R. equi DNA responsible for decomposition of the antibiotic strongly resembled those of monooxygenases acting upon phenolic compounds, consistent with the presence of a naphthalenyl moiety in the rifampicin molecule. Antibiotic resistance conferred by the gene was surprisingly specific to the semisynthetic compounds rifampicin (150-fold increase) and rifapentine (70-fold). Similar specificity was observed with the other inactivation gene cloned, which ribosylates rifampicin at the 23-hydroxyl position. A 60-bp sequence upstream of the monooxygenase and ribosylation genes is strikingly similar suggesting a shared pattern of regulation. Rhodococcal arsenic resistance and azo dye degradation genes have been cloned and characterised.

Actinomycetales↗
PubMed1982

A survey of the structures of mycolic acids in Corynebacterium and related taxa.

Acid methanolysates of 104 strains of coryneform and related bacteria were examined for mycolic acids by thin-layer chromatography and mass spectrometry. The mycolic acids of Corynebacterium sensu stricto strains were not uniform in size and structure, and considerable variation existed within the approximate limiting range of C22 to C36. Two species, Corynebacterium bovis and 'Corynebacterium mycetoides', were particularly distinctive; the former had exceptionally low molecular weight mycolic acids (C22 to C32), whereas the latter contained major amounts of mycolates with a side-chain possessing an odd number of carbon atoms. Caseobacter polymorphus contained mycolic acids of a similar size (C30 to C36) to those of true corynebacteria. The mycolates of organisms assigned to the genus Rhodococcus were generally larger (C30 to C56), although a clear distinction between two corynebacteria and rhodococci cannot presently be made by analysis of mycolic acids alone. Strains labelled 'Arthrobacter roseoparaffinus', Corynebacterium equi and Corynebacterium hoagii contained mycolic esters with molecular weights 'intermediate' in size between those of true corynebacteria and rhodococci. The mycolic acid data correlate well with other major trends in coryneform taxonomy and support earlier suggestions that they are of value in the classification of the group.

Arthrobacter↗
PubMed1989

[The significance of detecting Corynebacterium equi in the conjunctiva of children in Cairo].

The probable correlations between certain Corynebacterium are discussed. Carpenter et al. (1976) describes a Corynebacterium equi-pneumonia in a patient with Hodgkin's disease; Gardner et. al. (1976) also reports on a case of pneumonia. Golub et. al. (1967) demonstrates a lung abscess resulting from Corynebacterium equi. Williams et. al. (1971) demonstrates a thoracic infection in an immunosuppressed patient. Although, our findings have been demonstrated only in conjunctivitis of children, hitherto descriptions of Corynebacterium equi in diseases of the lungs, especially in the case of a low immune response in certain sections of the population should be taken into account. Further investigations of the numerous dead donkeys with severe clinical symptoms of lung sequela are necessary.

Actinomycetales Infections↗
PubMed1990

Human pulmonary infection with Corynebacterium equi.

A 28 year old man with no underlying disease developed a cavity and multiple nodules in the lung from which Corynebacterium equi was isolated. He experimented with organic solvents and microorganisms including Corynebacterium species for several years. Computed tomography of his pulmonary lesions revealed that these nodules were related to the bronchial tree. Histologically, the lesions were compatible with nonspecific inflammatory changes. The clinician must suspect the pulmonary infections with Corynebacterium species even if the patient has no underlying disease.

Actinomycetales Infections↗