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Antitumor activity of intralesionally administered Nocardia opaca preparations in rat and mouse tumors: a comparison with BCG and Corynebacterium parvum.

Three Nocardia products: delipidated cells, lysozyme digest and Nocardia Water Soluble Mitogen (NW SM), have been assayed in regression experiments and compared with living BCG and killed C. parvum in rat and mouse fibrosarcomas transplanted intradermally. Intratumor injection of these Nocardia products induced regression in the BCG sensitive McFiFi2 (S) tumor. These substances were active at a dose of 1 mg, the lysozyme extract and NW SM also being active at 0.1 mg. Association with mineral or vegetable oil increased the efficiency of delipidated cells, and under these conditions, regression of tumors implanted contralaterally to treated tumors was also obtained.

Animals↗

Antitumoral activity of an immunomodulatory fraction of Nocardia opaca: mechanism of action.

Immunomodulatory substances have been used as antineoplastic agents in experimental and human systems. Many of these agents were derived from microorganisms. Several biologically active fractions have been isolated from Nocardia. These derivatives were shown to induce interferon production, to activate natural killer cells and macrophages and to exert an antitumoral effect. We attempted to examine the mechanism of the antitumoral activity of the Nocardia water-soluble mitogen (NWSM). The tumor tested was the Lewis lung carcinoma (3LL). Regular histological examination and identification of the cellular immune reaction by monoclonal antibodies against macrophages (Mac 1 antigen), B- (IgG expressing) and T-lymphocytes (anti-Lyt-1), analysed by flow cytometry, were performed on samples of the tumor site and of the spleen. Intratumoral administration of the immunomodulators resulted in a massive accumulation of inflammatory cells around the tumor in mice treated with NWSM. The thick rim of infiltrating cells consisted of macrophages and lymphocytes, while the nontreated tumor was found to provoke only a scanty lymphocyte infiltration. Macrophages were, therefore, present at the tumor site and were directly implicated in the antitumoral effect of the Nocardia immunomodulator. T-lymphocytes were also observed at the site of the tumor. The spleen reaction consisted of marked extramedullary hematopoiesis and enlarged follicles containing prominent germinal centres (assessed also by a FACS-demonstrated increase in B-lymphocytes). In view of the inefficiency of chemotherapy in the treatment of advanced cancer, it is of major importance to explore alternative cancer treatment modalities. Immunotherapy is a particularly interesting alternative since it can potentially affect metastatic disease.

Adjuvants, Immunologic↗

Serotaxonomical analyses of strains referred to Nocardia amarae and Rhodococcus equi.

Four strains of Nocardia amarae and four strains of Rhodococcus equi (earlier designated Corynebacterium equi) were analysed by means of the comparative immunodiffusion technique for taxonomical purposes. Nineteen reference precipitation systems, representing different species of Corynebacterium, Mycobacterium, Nocardia, Rhodococcus, Streptomyces, and related taxa were employed. The N. amarae strains differed serologically from the reference strains of Nocardia and their assignment to the latter genus was therefore questioned. Furthermore, the results provided additional evidence for the view that R. equi belongs to the genus Rhodococcus and not to the genus Corynebacterium.

Corynebacterium↗

Characterization of the ribosomal rrnD operon of the cephamycin-producer 'Nocardia lactamdurans' shows that this actinomycete belongs to the genus Amycolatopsis.

The cephamycin producer strain 'Nocardia lactamdurans' contains four ribosomal RNA (rrn) operons. One of them (rrnD) was cloned from a DNA library in the bifunctional cosmid pJAR4. A 2229 bp region of rrnD has been sequenced. The 'N. lactamdurans' rrnD operon maintains the canonical order 5'-16S-23S-5S-3'. Four of the consensus Gürtler-Stanisch sequences were found in the 16S rRNA gene and a fifth one in the sequenced 5' region of the 23S rRNA gene. The anti Shine-Dalgarno sequence of 'N. lactamdurans' (located in the 3'-end of the 16S rRNA gene) was found to be 5'-CCUCCUUUCU-3' and is identical to that of Corynebacterium lactofermentum and Mycobacterium tuberculosis. A phylogenetic analysis of 'N. lactamdurans' by the neighbor-joining method using the entire 16S rRNA nucleotide sequence revealed that this actinomycete is closely related to Amlycolatopsis orientalis subsp orientalis, Amycolatopsis coloradensis, Amycolatopsis alba, Amycolatopsis sulphurea and other Amycolatopsis sp. but only distantly related to species of the genus Nocardia. The cephamycin producer 'N. lactamdurans' NRRL 3802 should be, therefore, classified as Amycolatopsis lactamdurans. The deduced secondary structure of the 16S rRNA is very similar to that of A. colorandensis and A. alba but different from those of species of the Nocardia genus supporting the incorporation of 'N. lactamdurans' into the genus Amycolatopsis.

Actinomycetales↗

Nocardia farcinica brain abscess: a case report and review of the literature.

Nocardia infection is not rare as generally been assumed and its mortality rate is high. It is isolated from plants and soil in most regions of the world. The hosts usually have predisposing conditions and the infection is acquired through the respiratory tract or skin. Nocardial organisms have a tendency to disseminate hematogenously from the primary site of infection to brain, kidney, joints, bones and eyes. Sulfonamides are preferred empirically for the treatment. Because of high relapse rates, the treatment must be continued for 12 months. In nocardia farcinica infection, the characteristic resistance pattern to cephalosporines must be kept in mind. In this article, a rare case of nocardia farcinica infection with a solitary cerebral abscess is presented and the literature is reviewed.

Brain Abscess↗

Desulfurization of diesel oils by a newly isolated dibenzothiophene-degrading Nocardia sp. strain CYKS2.

A dibenzothiophene (DBT)-degrading bacterial strain was isolated from dyeing industry wastewater and identified as Nocardia sp. CYKS2. The newly isolated bacterial strain Nocardia sp. CYKS2 was able to convert DBT to 2-hydroxybiphenyl (2-HBP) as the dead-end metabolite through a sulfur-specific pathway. Other organic sulfur compounds, such as thiophene derivatives, thiazole derivatives, sulfides, and disulfides were also desulfurized by Nocardia sp. CYKS2. In batch culture, 0.2 mM DBT was completely desulfurized in 60 h. After DBT was depleted, neither cell growth nor 2-HBP production was observed. When a model oil which DBT was dissolved in hexadecane was treated with growing cells, DBT was desulfurized from 10 mM to about 2 mM in 80 h. In this case, desulfurization rate was 0.279 mg-sulfur/(L-dispersion.h), which was about 2.5 times higher than that in the previous case of batch culture. When diesel oil was treated, the sulfur content decreased from 0.3 to 0.24 wt % in 48 h. A volumetric phase ratio of oil to water was 1/10 in this case. The sulfur decreased from 0.3 to 0.2 wt % in 48 h, when the volumetric phase ratio was 1/20. The desulfurization rates were 0.909 and 0.992 mg-sulfur/(L-dispersion.h), respectively.

Biodegradation, Environmental↗

Blastic transformtion of mouse spleen lymphocytes by a water-soluble mitogen extracted from Nocardia.

A water-soluble extract of Nocardia markedly increased in vitro [(3)H]thymidine incorporation by mouse spleen lymphocytes. The blastogenic activity of the extract and lipopolysaccharide was studied comparatively on various mouse lymphocyte subpopulations. The data obtained by [(3)H]thymidine incorporation and by electron microscopy have demonstrated that this preparation stimulates selectively mouse bone-marrow-derived cortisone-sensitive lymphocytes. This stimulation is related neither to a natural infection of mice with Nocardia organisms nor to the presence in Nocardia water-soluble mitogen of a lipopolysaccharide contaminant or of a lipopolysaccharide-like material.

Animals↗

Disk diffusion susceptibility testing of Nocardia species.

The effectiveness of 13 antimicrobial agents against 51 clinical isolates of Nocardia was determined with use of agar dilutions and disk diffusion method. Amikacin inhibited less than 90% of isolates and, like the other aminoglycosides, showed good correlation between minimal inhibitory concentrations and sizes of zones of inhibition around the disks. Both sulfisoxazole and trimethoprim-sulfamethoxazole were very active, although they required a 2- to 3-log lower inoculum for demonstration of susceptibility. Results with the two sulfa disks were variable, but they did allow distinction between sensitive and intermediate strains. All of the isolates of Nocardia were inhibited by 6.3 microng of minocycline; however, the degree of susceptibility could not be determined by zone diameters. Only two-thirds of these clinical isolates of Nocardia grew rapidly enough to be assayed by either susceptibility method.

Anti-Bacterial Agents↗

Acidification of phagosomes in murine macrophages: blockage by Nocardia asteroides.

Most strains of Nocardia asteroides are susceptible to the detrimental effects of pH 5 when grown in buffered brain-heart infusion broth. Preventing phagosomal acidification may be a mechanism by which this organism survives the microbicidal activity of macrophages. Fluorescein isothiocyanate was conjugated to the surface of Nocardia and Saccharomyces to form pH-sensitive fluorescent probes. The fluorescent emission, and thus the pH, of this probe was quantitated within individual phagosomes by using a computerized cytospectrophotometer. When either live or dead cells of virulent N. asteroides strain GUH-2 were ingested, the phagosomal pH remained above pH 7 for 2 hr. A nonpathogenic soil isolate, N. asteroides strain 19247, only partially blocked acidification. In contrast, when Saccharomyces was used as a control for normal response, the pH decreased to approximately pH 5. Therefore, virulent N. asteroides blocks phagosomal acidification. Because killed Nocardia act in the same manner, this inhibition of acidification appears to be associated with cellular components. This capacity to prevent phagosomal acidification may be prerequisite to the survival of intracellular pathogens.

Animals↗

Case report: Nocardia osteomyelitis.

Osteomyelitis is an unusual manifestation of infection with Nocardia spp, and most cases result from direct extension from a primary lung or cutaneous lesion. The authors report what they believe to be the first case of Nocardia vertebral osteomyelitis occurring postoperatively, and review the literature on the 19 previously reported cases of Nocardia osteomyelitis due to hematogenous dissemination or direct inoculation, excluding those occurring from direct extension of a mycetoma or primary lung infection.

Adult↗

The steroid-9 alpha-hydroxylation system from Nocardia species.

The steroid 9 alpha-hydroxylase from Nocardia species M117 was found to be an electron-transport chain consisting of an NADH-dependent flavoprotein reductase and two iron-sulfur proteins named protein II and protein III. The components were partially purified. The flavoprotein reductase from Nocardia species M117 was enriched 20-fold to 100 units/mg and protein III 200-fold to 2400 units/mg protein. Protein II has a molecular weight of approximately 214 000. The purification factor of protein II was not determined. The absorption spectrum of protein II shows a maximum at 425 nm in the oxidized form and maxima at 510 nm, 415 nm and 370 nm in the reduced state; whereas protein III has a prominent maximum at 452 nm in the oxidized form and no absorption maximum in the reduced state. Carbon monoxide treatment of the reduced forms of protein II and protein III showed no maximum at 450 nm. Both proteins II and III are sensitive to oxygen. The hydroxylase activity can be reconstituted from the isolated components. Activity of the combined proteins was demonstrated by product analysis and NADH consumption produced by the addition of progesterone. Protein III catalyzes the reduction of cytochrome c in the presence of NADH and Nocardia flavoprotein reductase. The reconstitution of hydroxylase activity from cytochrome-free enzyme preparations excludes the participation of cytochrome P-450 in this steroid hydroxylase system.

Bacterial Proteins↗

Incidence of pulmonary infection due to Nocardia species in Nigeria.

Pulmonary infection due to Nocardia sp. was investigated in 600 patients of various bronchopulmonary disorders by direct microscopy of sputum samples and cultures on appropriate media. Pathogenic Nocardia species were isolated from 25 patients, giving 4.1% incidence of infection. The species of Nocardia represented were N. asteroides (21 isolates), N. otitidis-caviarum and N. brasiliensis (2 isolates each). Paraffin baiting technique proved to be more efficacious than culturing on glucose nutrient agar.

Adolescent↗

Replication and inheritance of Nocardia plasmid pC1.

Nocardia sp. C-14-1, isolated from acrylic fiber wastewater, can degrade long-chain alkanes and succinonitrile efficiently. Here we report the characterization of an indigenous plasmid pC1. The overall nucleotide sequence of pC1 consisted of 5841 bp. The five ORFs, encoding a DNA recombinase, replication protein (Rep(pC1)) and three proteins of unknown function, were predicted on pC1. The Rep(pC1) displayed its homology with the Rep of Rhodococcus large plasmid p33701, suggesting a theta type of replication. An Escherichia coli plasmid (containing the single rep(pC1) gene) propagated autonomously in low copy number in Nocardia or Rhodococcus, suggesting that rep(pC1) was an essential gene for plasmid replication. The plasmid (containing the single rep(pC1) gene) presented as inheritance unstable hints that other pC1 loci were required for the stable inheritance of plasmids. By comparison of the plasmid-borne Rep proteins, we classify Rhodococcus or Nocardia plasmids into four groups.

DNA Replication↗

In vitro susceptibilities of Nocardia species to newer antimicrobial agents.

The in vitro activities of various quinolones, two newer cephalosporins, and imipenem against 23 strains of Nocardia asteroides, 4 strains of Nocardia brasiliensis, and 4 strains of Nocardia caviae were determined by an agar dilution method. PD-117558, a newer carboxyquinolone, and imipenem were the most active agents tested, inhibiting 90% of N. asteroides isolates at an MIC of 2 micrograms/ml. Of the 23 strains of N. asteroides, 15 were susceptible to cefpirome and 10 were susceptible to ciprofloxacin. The N. brasiliensis and N. caviae strains were very susceptible to PD-117558 (MIC, less than or equal to 1 microgram/ml), moderately susceptible to ciprofloxacin, and resistant to most of the other tested drugs.

Anti-Bacterial Agents↗

Inactivation of rifampin by Nocardia brasiliensis.

Rifampin was glycosylated by a pathogenic species of Nocardia, i.e., Nocardia brasiliensis. The structures of two glycosylated compounds (RIP-1 and RIP-2) isolated from the culture broth of the bacterium were determined to be 3-formyl-23-(O-[beta-D-glucopyranosyl])rifamycin SV and 23-(O-[beta-D-glucopyranosyl])rifampin, respectively. Both compounds lacked antimicrobial activity against other gram-positive bacteria as well as the Nocardia species.

Glycosylation↗

In vitro activities of linezolid against multiple Nocardia species.

Linezolid was tested by broth microdilution against 140 clinical Nocardia isolates belonging to seven species. The MIC at which 50% of the strains are inhibited (MIC50) and MIC90 for all species other than Nocardia farcinica were 2 and 4 microg/ml. Linezolid is the first antimicrobial agent demonstrated to be active against all Nocardia species.

Acetamides↗

Oxidation of alkyl-substituted cyclic hydrocarbons by a Nocardia during growth on n-alkanes.

Nocardia 107-332, a soil isolate, oxidizes short-chain alkyl-substituted cyclic hydrocarbons to cyclic acids while growing on n-alkanes. Cyclic acids are produced also from relatively long-chain alkyl-substituted cyclics such as n-nonylbenzene or n-dodecylbenzene which alone support growth in a mineral-salts medium. omega-Oxidation of the alkyl substituents is followed by beta-oxidation. It is of particular interest that cyclic acids such as cyclohexaneacetic and phenylacetic with C(2) residual carboxylic acid substituents are resistant to further oxidation by the nocardia but cyclic acids with C(1) or C(3) substituents are readily oxidized and utilized for growth. The specificity of microbial oxidations is demonstrated by the conversion of p-isopropyltoluene (p-cymene) to p-isopropylbenzoic acid in n-alkane, growth-supported nocardia cultures.

Alkanes↗

Induction of interferon synthesis in mice by fractions from Nocardia.

Three fractions of Nocardia, Nocardia water-soluble mitogen (NWSM), Nocardia water-soluble mitogen pellet (NWSMP), and the cell wall peptidoglycan, which are mitogenic for B lymphocytes, were able to induce circulating interferon in mice, NWSMP and NWSM being the most active. The peak of interferon appeared about 2 h after injection. The interferon induced by NSWMP and NWSM was acid stable and antigenically related to viral interferon, as shown by neutralization with antibodies directed against Newcastle disease virus-induced interferon.

Animals↗