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PubMed1999

Sequence analysis of the oxidase/reductase genes upstream of the Rhodococcus erythropolis aldehyde dehydrogenase gene thcA reveals a gene organisation different from Mycobacterium tuberculosis.

The sequence of the DNA region upstream of the thiocarbamate-inducible aldehyde dehydrogenase gene thcA of Rhodococcus erythropolis NI86/21 was determined. Most of the predicted ORFs are related to various oxidases/reductases, including short-chain oxidases/reductases, GMC oxidoreductases, alpha-hydroxy acid oxidases (subfamily 1 flavin oxidases/dehydrogenases), and subfamily 2 flavin oxidases/dehydrogenases. One ORF is related to enzymes involved in biosynthesis of PQQ or molybdopterin cofactors. In addition, a putative member of the TetR family of regulatory proteins was identified. The substantial sequence divergence from functionally characterized enzymes precludes a reliable prediction about the probable function of these proteins at this stage. In Mycobacterium tuberculosis H37Rv, most of these ORFs have homologs that are also clustered in the genome, but some striking differences in gene organization were observed between Rhodococcus and Mycobacterium.

Aldehyde Dehydrogenase↗

PubMed2002

Identification of virulence-associated antigens and plasmids in Rhodococcus equi from patients with acquired immune deficiency syndrome and prevalence of virulent R. equi in soil collected from domestic animal farms in Chiang Mai, Thailand.

The prevalence of virulent Rhodococcus equi in soil collected from 17 domestic animal farms (from 12 cattle, 1 pig, and 4 horse farms) and in 6 clinical specimens from patients with acquired immune deficiency syndrome (AIDS) in Chiang Mai, Thailand, was investigated. The isolates were tested for the presence of 15-17-kDa antigens (VapA) and a 20-kDa antigen (VapB) by immunoblotting and for the presence of virulence plasmid DNA. Rhodococcus equi was isolated from most soil samples (68 of 80) obtained from the 17 farms, with 2.0 x 10(2) to 6.0 x 10(5) colony-forming units per gram of soil. We detected VapA in none of the 537 isolates from the soil samples. In one isolate from a pig farm, both VapB and virulence plasmid DNA were detected. Of the 6 clinical isolates from patients with AIDS, however, 4 isolates contained both VapB and virulence plasmid DNA. The remaining 2 isolates were avirulent.

AIDS-Related Opportunistic Infections↗

PubMed1999

[Pulmonary infection from Rhodococcus equi after renal transplantation. Review of the literature].

Rhodococcus Equi, a strictly aerobic Gram positive coco-bacillus, is a pathogen for horses and foals. It may induce opportunistic infections and is described in AIDS infected patients. We report the case of a 47-year old man, breeder of horses, with kidney transplant who has presented, 8 years after his graft, an impairment of health, a fever and evidence of pulmonary disease. The pulmonary biopsy under scanner guidance and microbiology study, has displayed the diagnosis of Rhodococcus equi infection. The evolution has been favorable with double antibiotherapy (follow-up 27 months). Ten comparable observations have been published after organ transplantation: (kidney: 8; heart: 1; liver: 1). Pulmonary locations are widely predominant. The animal contact is found only in 30% of cases. The presentation of the sickness has been compared to pulmonary tuberculosis or to nocardiosis, pathologies often observed in this context of immunosuppression. The antibiotic treatment is difficult and should required two bactericidal antibiotics. A surgical lobectomy can be envisaged in case of relapse. The mortality is 30%.

Actinomycetales Infections↗

PubMed2000

Successful treatment of Rhodococcus equi pulmonary infection in a renal transplant recipient.

The rhodococcus is a mycobacterium-like organism which is normally a pathogen in foals. It usually spreads by direct contact or by aerosol from horse faeces and causes pyogranulomatous pulmonary infections. Occasionally, it acts opportunistically to infect immuno-compromised human hosts, most commonly those with the acquired immune deficiency syndrome (AIDS). Here we report a pulmonary infection by Rhodococcus equi in a renal transplant recipient who was successfully treated. The literature on this infection in transplant recipients is also reviewed with respect to manifestations and treatment.

Actinomycetales Infections↗

PubMedDate not supplied

[Assimilation of propane and properties of propan monooxygenase from Rhodococcus erythropolis 3/89].

The ability of propane-assimilating microorganisms of the genus Rhodococcus to utilize metabolites of the terminal and subterminal pathways of propane oxidation was studied. Propane monooxygenase of Rhodococcus erythropolis 3/89 was shown to be the an inducible enzyme catalyzing epoxidation and hydroxylation of organic compounds. The optimum conditions for epoxidation of gaseous and liquid alkenes and hydroxylation of aromatic carbohydrates were found.

Catalysis↗

PubMed2001

Prevalence of virulent Rhodococcus equi in isolates from soil collected from two horse farms in South Africa and restriction fragment length polymorphisms of virulence plasmids in the isolates from infected foals, a dog and a monkey.

The prevalence of virulent Rhodococcus equi in soil isolates from two horse farms in South Africa and nine clinical isolates from six foals, a foal foetus, a dog, and a monkey was investigated. The isolates were tested for the presence of virulence plasmid DNA and 15- to 17-kDa antigens by immunoblotting. Rhodococcus equi was isolated from almost all of the soil samples obtained from the two farms with 5.0 x 10(1) to 3.3 x 10(4) colony forming units per gram of soil. Virulent R. equi was isolated from three soil samples from one of the farms and appeared in 3.8% (three of 80 isolates), but not in any of the 182 isolates from the other farm. Of the three virulent R. equi isolates, one contained an 85-kb type I plasmid and two an 87-kb type I plasmid. Of nine clinical isolates from the foals, foal foetus, dog and monkey, five from the foals were virulent R. equi which expressed the virulence-associated antigens and contained a virulence plasmid 85-kb type I, and were all isolated from cases of pneumonia typical of that induced by R. equi in young foals living in widely separated areas in South Africa. The isolates from the other four foals, the dog and the monkey were avirulent R. equi.

Actinomycetales Infections↗

PubMedDate not supplied

[The efficient accumulation of cesium ions by Rhodococcus cells].

Bacteria of the genus Rhodococcus were found to be able to accumulate cesium by means of active transport and nonspecific sorption on the cell surface structures. The maximum removal (up to 97%) of cesium from a medium with ammonium acetate was observed at 28 degrees C, pH 7.8-8.6, and an equimolar content (0.2 mM) of potassium and cesium ions in the medium. The most active cesium-accumulating Rhodococcus sp. strains can be used for purification of industrial wastewaters contaminated with radionuclides.

Cesium↗

PubMedDate not supplied

[Effects of nitriles and amides on the growth and the nitrile hydratase activity of the Rhodococcus sp. strain gt1].

Effects of some nitriles and amides, as well as glucose and ammonium, on the growth and the nitrile hydratase (EC 4.2.1.84) activity of the Rhodococcus sp. strain gt1 isolated from soil were studied. The activity of nitrile hydratase mainly depended on carbon and nitrogen supply to cells. The activity of nitrile hydratase was high in the presence of glucose and ammonium at medium concentrations and decreased at concentrations of glucose more than 0.3%. Saturated unsubstituted aliphatic nitriles and amides were found to be a good source of nitrogen and carbon. However, the presence of nitriles and amides in the medium was not absolutely necessary for the expression of the activity of nitrile hydratase isolated from the Rhodococcus sp. strain gt1.

Amides↗

PubMed1992

[Rhodococcus equi infection causing pulmonary malacoplakia in a patient with acquired immune deficiency syndrome].

Rhodococcus equi is a pathogen for some animal species. It can cause opportunistic pulmonary infections in immunocompromised people. The authors describe such an infection that causes malacoplakia in a patient with acquired immunodeficiency syndrome. The likeness between lesions due to Rhodococcus equi and those due to other opportunistic germs as Mycobacterium avium-intracellulare is emphasized.

AIDS-Related Opportunistic Infections↗

PubMed1992

Nitrilase from Rhodococcus rhodochrous J1. Sequencing and overexpression of the gene and identification of an essential cysteine residue.

The amino acid sequences of the NH2 terminus and internal peptide fragments of a Rhodococcus rhodochrous J1 nitrilase were determined to prepare synthetic oligonucleotides as primers for the polymerase chain reaction. A 750-base DNA fragment thus amplified was used as the probe to clone a 5.4-kilobase PstI fragment coding for the whole nitrilase. The nitrilase gene modified in the sequence upstream from the presumed ATG start codon was expressed to approximately 50% of the total soluble protein in Escherichia coli. The predicted amino acid sequence of the nitrilase gene showed similarity to that of the bromoxynil nitrilase from Klebsiella ozaenae. The 5,5'-dithiobis(2-nitrobenzoic acid) modification of the nitrilase from R. rhodochrous J1 resulted in inactivation with the loss of one sulfhydryl group/enzyme subunit. Of 4 cysteine residues in the Rhodococcus nitrilase, only Cys-165 is conserved in the Klebsiella nitrilase. Mutant enzymes containing Ala or Ser instead of Cys-165 did not exhibit nitrilase activity. These findings suggest that Cys-165 plays an essential role in the function of the active site.

Amino Acid Sequence↗

PubMedDate not supplied

[Variation in the composition of Rhodococcus rodochrous GNP-OHP-38r cell membrane fatty acids in response to temperature and salinity].

The members of the genus Rhodococcus are frequent and abundant inhabitants of polluted areas with hydrocarbons and they resist the salinity present in the central Patagonia. This genus has good capacity to eliminate pollution produced by hydrocarbons that constitutes the biggest pollutant agent in the region. The present work studies the answer in the composition of its fatty acids under the combined action of the temperature and saline concentration of an isolated stump of a landfarming system. The strategy of Rhodococcus rodochrous strain GNP-OHP-38r in front of the thermal-osmotic stress is the increase of the percentage of the total saturated fatty acids (n:0); fatty acids branched in the terminal carbon with hidroxyl group in position 2 (n:0 iso 2 OH) and saturated with group methyl in carbon 10 (n:0 10 metil) when the temperature is increased. These acids increase while the percentage of n:1 cis decrease.

Membrane Lipids↗

PubMedDate not supplied

[Production of surfactants by Rhodococcus erythropolis strain EK-1, grown on hydrophilic and hydrophobic substrates].

The ability of Rhodococcus erythropolis strain EK-1 to produce surfactants when grown on hydrophilic (ethanol and glucose) and hydrophobic (liquid paraffins and hexadecane) substrates was studied. The strain was found to produce surfactants with emulsifying and surface-active properties. The production of surfactants depended on the composition of the nutritive medium, nature and concentration of the sources of carbon and nitrogen, and duration of cultivation. Chemically, surfactants produced by Rhodococcus erythropolis EK-1 grown on ethanol are a complex of lipids with polysaccharide-proteinaceous substances. The lipids include glycolipids (trehalose mono- and dicorynomycolates) and common lipids (cetyl alcohol, palmitic acid, methyl n-pentadecanoate, triglycerides, and mycolic acids).

Alkanes↗

PubMed2005

Isolation and characterization of a rhodococcus species strain able to grow on ortho- and para-xylene.

Rhodococcus sp. strain YU6 was isolated from soil for the ability to grow on o-xylene as the sole carbon and energy source. Unlike most other o-xylene-degrading bacteria, YU6 is able to grow on p-xylene. Numerous growth substrate range experiments, in addition to the ring-cleavage enzyme assay data, suggest that YU6 initially metabolizes o- and p-xylene by direct aromatic ring oxidation. This leads to the formation of dimethylcatechols, which was further degraded largely through meta-cleavage pathway. The gene encoding meta-cleavage dioxygenase enzyme was PCR cloned from genomic YU6 DNA using previously known gene sequence data from the o-xylene-degrading Rhodococcus sp. strain DK17. Subsequent sequencing of the 918-bp PCR product revealed a 98% identity to the gene, encoding methylcatechol 2,3-dioxygenase from DK17. PFGE analysis followed by Southern hybridization with the catechol 2,3-dioxygenase gene demonstrated that the gene is located on an approximately 560-kb megaplasmid, designated pJYJ1.

Blotting, Southern↗

PubMed2005

[The innate ability of Rhodococcus sp. SDUZAWQ to tolerate sulfur in petroleum].

Removal of sulfur from petroleum can be accomplished by various means. One method is to use microorganisms, such as bacteria. In the present study, strain Rhodococcus sp. SDUZAWQ was employed to test the effects of various concentrations of dibenzothiophene (DBT) and sulfate, had on this removal process. Desulfurization was accomplished, using Basal Salts Medium (BSM), supplemented with 0.2mmol/L DBT and different concentrations of Na2SO4. Growth of SDUZAWQ was pronounced, even when the concentration of DBT was increased to 6mmol/L. Furthermore, it should be noted that the end product of DBT desulfurization, 2 hydroxybiphenyl (2-HBP), was detected as well. This finding was significant because it demonstrated the bacteria' s ability to withstand high concentrations of organosulfur. Dibenzothiophene was utilized when both DBT and Na2SO4 were present in the culture medium. Additionally, 2-HBP was produced. These data are in contrast to previous studies that indicated that DBT could not be metabolized by Rhodococcus sp. in the presence of sulfate. Finally, cloning and sequencing of the gene cluster dszABC, its upstream regulatory sequence and dszD, demonstrated that they share 99%, 100% and 100% with those of R. erythropolis IGTS8, respectively.

Biphenyl Compounds↗

PubMed2005

[Sequence and structure analysis of cryptic plasmid pN30 from oil-oxidizing strain Rhodococcus erythropolis 30].

Nucleotide sequence of cryptic plasmid pN30 from a Rhodococcus erythropolis 30 soil isolate was determined. Plasmid DNA consists of 5403 nucleotide pairs and contains about 62% GC pairs, which is typical of Rhodococcus DNA. No significant homology was determined between the pN30 DNA sequence and those of known plasmids. Computer-aided analysis of pN30 sequence revealed open reading frames that encode proteins strongly homologous to replicative proteins encoded by small cryptic plasmids of different actinomycetes.

Amino Acid Sequence↗

PubMedDate not supplied

[The prospects of using bacteria of the genus Rhodococcus and microbial surfactants for the degradation of oil pollutants].

The possibility of accelerating oil degradation by an enrichment culture of oil-oxidizing microorganisms in the presence of bacteria of the genus Rhodococcus and microbial surfactants was studied. It was shown that the degree of consumption of crude oil (2% v/v) after 192 h of enrichment culture growth reached 84%. Inoculation of the active hydrocarbon-oxidizing strain Rhodococcus erythropolis EK-1 and exogenous surfactants produced by Pseudomonas sp. PS-27 increased this degree to 90% and 93-94%, respectively. On the grounds of these results, efficient methods of purification of the environment from oil pollutants can be developed.

Biodegradation, Environmental↗

PubMed1987

Experimental infection of piglets by aerosols of Rhodococcus equi.

The purpose of this study was to investigate experimental infection of the piglet as a model of Rhodococcus equi pneumonia in the foal. Three litters of eight piglets each were exposed to an aerosol of 3.4 X 10(7) R. equi per piglet per day for seven consecutive days. Over the next 23 days the piglets were observed for clinical signs of disease. Periodically after infection one piglet from each litter was killed, the lungs were cultured quantitatively for R. equi and the gross and microscopic pulmonary lesions were assessed. The only clinical evidence of disease was the occurrence of elevated temperatures in the infected piglets. Rhodococcus equi was slowly cleared from the piglets' lungs during the 23 days following aerosolization. Piglets sacrificed seven to ten days after aerosolization had the most extensive pulmonary lesions, consisting of severe consolidation of the cranioventral lobes. Microscopic examination revealed thickened interalveolar septa and alveoli containing many neutrophils and macrophages with intracytoplasmic Gram-positive coccobacilli. The pulmonary lesions in these piglets differed from those of naturally infected foals in that they were not characterized by macrophage-rich abscesses and the infection gradually resolved.

Actinomycetales Infections↗

PubMed1993

Lack of residual lung damage in horses in which Rhodococcus equi-induced pneumonia had been diagnosed.

The effect of prior Rhodococcus equi-induced pneumonia on pulmonary health was investigated in 5 horses (< 24 months old) using endoscopy, radiography, hematologic and bronchoalveolar lavage analyses, and pulmonary function testing. Rhodococcus equi-induced pneumonia had been diagnosed in principal horses when they were foals. Diagnosis was based on positive results of transtracheal aspiration and thoracic radiography at the time of initial clinical examination. Results of reevaluation of the respiratory system of these horses (R+) were compared with those of 5 age-matched healthy horses (R-) that lacked clinical or historical evidence of foalhood pneumonia. Significant differences in variables between the 2 groups of horses were not evident. In both groups, most horses had radiographic evidence of an accentuated bronchointerstitial pattern, although results of analysis of bronchoalveolar lavage specimens were normal and mononuclear cells predominated. Variability in results of the pulmonary function tests was observed within the between the 2 groups of horses. Only normalized dynamic lung compliance was slightly lower in the previously infected horses, but this difference was not significant. We concluded that horses previously infected with and successfully treated for R equi-induced pneumonia do not have detectable evidence of residual lung damage.

Actinomycetales Infections↗