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PubMed1982

Enhanced resistance to Nocardia brasiliensis infection in mice depleted of antigen-specific B cells.

This study deals with the roles of T and B cells in Nocardia brasiliensis infection in mice. Nocardia injected into the animals' footpads caused inflammatory responses and mycetomas in situ, resulting in granulomatous lesions of subcutaneous tissues and eventual bone destruction. These clinical features resemble those of humans infected with Nocardia. The effect, if any, of antibody was studied by passively transferring anti-Nocardia serum into either immunologically normal or T-deficient infected mice. Such transfers had no protective function in either group. To the contrary, the antibody seemed to favor infection and worsen bone disease compared to that in mice not given antibody. Furthermore, passive transfer of the antibody along with injection of Nocardia coated with the antibody magnified the severity of subsequent symptoms. Although these experiments ruled out any role for antibody in protection from Nocardia, they did not directly prove T cell participation in such resistance. Therefore, the role of T cells during Nocardia infection was examined further by transferring spleen cells depleted of B lymphocytes bearing receptors for a Nocardia extract (NE). Lethally irradiated mice reconstituted with a population depleted of NE-specific B cells totally lacked the ability to form antibodies to NE; however, they mounted effective delayed-type hypersensitivity reactions and completely controlled their Nocardia infection, establishing the importance of cell-mediated immunity in halting this disease process.

Animals↗
PubMed2002

Nocardia farcinica spinal osteomyelitis.

STUDY DESIGN: A case of disseminated Nocardia farcinica infection with spine involvement is reported. OBJECTIVE: To describe the first case of Nocardia farcinica spinal osteomyelitis, and to propose spine instrumentation with debridement and multiple antibiotics for treatment of nocardia spinal osteomyelitis. SUMMARY OF BACKGROUND DATA: Only 11 cases involving Nocardia asteroides spinal osteomyelitis have been reported over the past 40 years. These case reports describe various presentations and treatments of nocardia spinal osteomyelitis. METHODS: A 54-year-old nonambulant, paraparetic man was admitted to the authors' hospital with acutely increased low back pain, fever, and signs of dementia. A disseminated Nocardia farcinica infection including spinal osteomyelitis at T11, T12, L1, L2, and L4; epidural abscess T10-L4, L5-S1 discitis, empyemas, cerebral abscess, and bilateral psoas abscess was noted. RESULTS: Antibiotic therapy, multiple debridements, and posterior instrumentation were performed to palliate the Nocardia farcinica infection. At a recent 3-year follow-up assessment, the patient was independent and ambulant. He had been off antibiotics for 5 months. CONCLUSIONS: Previous case reports of nocardia spinal osteomyelitis describe treatment with antibiotics, debridements, and arthrodesis with autologous bone graft. Prolonged recumbency ensued. In the reported case, a combination of antibiotics, debridements, arthrodesis, and posterior instrumentation for immediate stabilization of the spine resulted in a favorable outcome at 3 years.

Epidural Abscess↗
PubMed1993

Ultrastructural analysis of growth of Nocardia asteroides during invasion of the murine brain.

BALB/c mice were infected with 10(6) CFU of log-phase cells of Nocardia asteroides GUH-2 by tail vein injection (at this lethal inoculum dose, approximately 800 to 1,000 CFU becomes deposited in the brain). At 24 h after infection, the ultrastructural interactions of the nocardiae during growth within the murine brain were investigated. The nocardiae grew perivascularly in the pons, substantia nigra, hypothalamus, and thalamus portions of the brain, where they were either within or associated with most brain cell types. There appeared to be a propensity for growth within the soma of neurons and their axonal extensions. The nocardial cells were surrounded by 1 to 30 layers of membrane, and the innermost membrane was usually tightly adherent to the cell wall. This compartmentalization of nocardiae within brain cells could contribute to their failure to induce an inflammatory response or a cytopathic effect. Nevertheless, the bacteria were able to obtain adequate nutrients from the host to grow within the brain. The nocardiae were not completely inert, since some of the brain cells showed signs of degeneration. The myelin sheaths of axons were the most strongly affected, and there was evidence of demyelinization and axonal degeneration. Nocardiae growing within brain cells were phagocytized by compact, dense cells that were probably microglia. There was no ultrastructural evidence that the nocardiae were damaged by these phagocytes 24 h after infection; nevertheless, these cells may be important for the elimination of nocardiae from the brain during a nonlethal infection.

Animals↗
PubMed1995

Use of yeast killer system to identify species of the Nocardia asteroides complex.

We evaluated the ability of the yeast killer system to differentiate members belonging to the Nocardia asteroides complex (Nocardia asteroides, Nocardia farcinica, and Nocardia nova). Nocardia strains were selected randomly from clinical isolates. Type strains of each Nocardia species and recognized killer yeasts were taken from different collections. A clear area of inhibition surrounding the yeast cells demonstrated a positive killer effect on Nocardia spp. Two yeast strains, Pichia mrakii (K9) and Pichia lynferdii (K76), showed different killer activities against each Nocardia species. The group N. asteroides was identified as K9+ K76-, the group N. farcinica was identified as K9- K76-, and the group N. nova was identified as K9+ K76+. The three killer identifications correlated with specific taxonomic groups determined by using classical methods. The yeast killer system may be a useful means for identifying organisms within the N. asteroides complex.

Bacterial Typing Techniques↗
PubMed1989

[In vitro susceptibility of pathogenic Nocardia to beta-lactam antibiotics, especially imipenem, a carbapenem antibiotic].

In vitro antibacterial activity of 30 beta-lactam antibiotics including 2 beta-lactamase inhibitors (clavulanic acid and sulbactam) against 2 major pathogenic Nocardia, i.e. Nocardia asteroides group and Nocardia brasiliensis was studied. Among the antibiotics tested, a newly developed carbapenem antibiotic, imipenem (IPM), was found to be the most active, followed by oxacephem group antibiotic flomoxef (FMOX). IPM exhibited activity against only N. asteroides group (N. asteroides, Nocardia farcinica and Nocardia nova). On the other hand, FMOX showed activity against all pathogenic Nocardia tested. A 2- to 30-fold decreases in minimum inhibitory concentration (MIC) for N. asteroides, N. brasiliensis and N. farcinica was noted when antibiotics and beta-lactamase inhibitors were combined compared to antibiotics alone. Further combination and enzymatic studies indicated that all pathogenic Nocardia possess beta-lactamase except for a half of the strains of N. nova. These species' specific sensitivity patterns of pathogenic Nocardia are discussed in this paper with references to their taxonomic positions.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Fatty acid composition of the lipids of streptomycetes and their nocardia-like mutants].

The models "population--Nocardia-like spontaneous mutants" for 14 cultures of Streptomycetes and Streptoverticillium were used to assess the fatty acid composition of lipids as a criterion for generic differentiation of Streptomyces and Nocardia cultures. The composition of fatty acids in the Nocardia-like mutant Str. kanamyceticus RIA-771 was found to be identical with that of Nocardia asteroides RIA-43 and Nocardia brasiliensis RIA-440, i. e. generic chemotaxonomic traits "overlapped" in the process of spontaneous intraspecial variability. In different strains of one and the same species as well as in five different species, the quantitative composition of fatty acids either hardly changed in the process of intraspecial variability or the ratio between fatty acids changed, so that Nocardia-like mutants resembled typical cultures of the Nocardia genus in this characteristics. The results suggest that the quantitative composition of fatty acids of lipids cannot be regarded as a sufficiently reliable criterion for generic differentiation of Steptomyces and Nocardia cultures. This trait should be used only for additional characterization of cultures.

Chemical Phenomena↗
PubMed2004

Cloning, expression, purification, and characterization of Nocardia sp. GTP cyclohydrolase I.

The sequence of the gene from Nocardia sp. NRRL 5646 encoding GTP cyclohydrolase I (GCH), gch, and its adjacent regions was determined. The open reading frame of Nocardia gch contains 684 nucleotides, and the deduced amino acid sequence represents a protein of 227 amino acid residues with a calculated molecular mass of 24,563Da. The uncommon start codon TTG was identified by matching the N-terminal amino acid sequence of purified Nocardia GCH with the deduced amino acid sequence. A likely ribosomal binding site was identified 9bp upstream of the translational start site. The 3' end flank region encodes a peptide that shares high homology with dihydropteroate synthases. Nocardia GCH has 73 and 60% identity to the proteins encoded by the putative gch of Mycobacterium tuberculosis and Streptomyces coelicolor, respectively. Nocardia GCH was highly expressed in Escherichia coli cells carrying a pHAT10 based expression vector, and moderately expressed in Mycobacterium smegmatis cells carrying a pSMT3 based expression vector. Enterokinase digestion of recombinant Nocardia GCH, and in-gel digestion of Nocardia GCH and recombinant GCH followed by MALDI-TOF-MS analysis, confirmed that the actual subunit size of the enzyme was 24.5kDa. Thus, we conclude that the active form of native Nocardia GCH is a decamer. Our earlier incorrect conclusion was that the native enzyme was an octamer derived from the anomalous SDS-PAGE migration of the subunit.

Amino Acid Sequence↗
PubMed1985

Inhibition of Nocardia asteroides by neutrophils.

Neutrophils are found in lesions of Nocardia asteroides infection, but neutrophils kill few nocardiae in vitro. For determination of neutrophil inhibition of nocardiae, neutrophils and nocardiae were incubated together. Filament formation and amino acid uptake by nocardiae were inhibited for 7.5 hr. Thereafter, nocardiae extended long filaments from within neutrophils to the outside and increased their rate of amino acid uptake. Addition of freshly isolated neutrophils at 7.5 hr of incubation prolonged the inhibition. Electron micrographs revealed that neutrophils phagocytosed nocardiae but that most nocardiae did not appear damaged. Formalin and 2-deoxy-D-glucose abrogated the inhibition by neutrophils. Lysozyme and granule-cationic proteins inhibited amino acid uptake under some conditions. Lactoferrin and lactic acid had no effect, and the oxidative metabolic burst was not required. These findings and clinical observations suggest that inhibition of N. asteroides by neutrophils may be important in vivo.

Amino Acids↗
PubMed1995

A phylogenetic analysis of the genus Nocardia with 16S rRNA gene sequences.

Partial sequences of the 16S rRNA genes of the type strains of nine species of the genus Nocardia were determined following the isolation and cloning of the amplified genes. These sequences were aligned with the sequences of representatives of the genera Corynebacterium, Gordona, Mycobacterium, Rhodococcus, and Tsukamurella, and phylogenetic trees were inferred by using the Fitch-Margoliash and neighbor-joining methods. The genus Nocardia formed a distinct clade that was most closely associated with the genus Rhodococcus. The average level of sequence similarity found among the type strains of the Nocardia species was 97.2 +/- 0.7%. Two sublines were recognized within the Nocardia clade; one encompassed Nocardia asteroides and related species, and the other encompassed Nocardia otitidiscaviarum and allied taxa. Separation of the two sublines is based on differences in helix 37-1. The results of isoprenoid quinone analyses provided evidence that nocardiae can be distinguished from all other actinomycete taxa on the basis of their characteristic menaquinone profiles. Nocardiae typically contain hexahydrogenated menaquinones with eight isoprene units in which the two end units are cyclized.

Base Sequence↗
PubMed1982

Numerical and chemical classification of Nocardia amarae.

Twenty-one strains of Nocardia amarae and marker cultures of Mycobacterium, Nocardia, Rhodococcus and the 'aurantiaca' taxon were subjected to numerical phenetic analyses using 92 unit characters. The data were examined using the simple matching (SSM), Jaccard (SJ) and pattern (DP) coefficients and clustering was achieved using the unweighted average linkage algorithm. Neither cluster nor aggregate cluster composition was markedly affected by the coefficient used or by test error, estimated at 1.5%. The N. amarae strains formed a distinct and homogeneous cluster which showed its highest similarity to phena equated with Nocardia asteroides, Nocardia brasiliensis and Nocardia otitidis-caviarum. The non-hydroxylated fatty acid composition and overall size of the mycolic acids was similar to that found to be characteristic of Nocardia sensu stricto, though the long-chain in the 2-position of the mycolic acids was relatively much richer in monounsaturated components. Nocardia amarae, in containing dihydrogenated menaquinones with nine isoprene units, is clearly distinguished from established representatives of Nocardia.

Fatty Acids↗
PubMed2003

Nocardia caishijiensis sp. nov., a novel soil actinomycete.

A soil isolate, strain F829T, which had provisionally been assigned to the genus Nocardia, was subjected to a polyphasic taxonomic study. An almost complete 16S rDNA sequence was determined for this strain; the sequence was aligned with available sequences for nocardiae and phylogenetic trees were inferred using three tree-making algorithms. The organism showed a combination of phenotypic properties typical of nocardiae and formed a distinct phyletic line within the evolutionary radiation of species of the genus Nocardia, being most closely related to Nocardia asteroides ATCC 19247T. Strain F829T was readily distinguished from representatives of species of Nocardia with validly published names on the basis of phenotypic data, notably from the type strain of N. asteroides. It is proposed that the organism be recognized as a novel species of Nocardia, Nocardia caishijiensis sp. nov. The type strain is F829T (=AS 4.1728T=JCM 11508T).

DNA, Bacterial↗
PubMed2006

Contribution of rpoB2 RNA polymerase beta subunit gene to rifampin resistance in Nocardia species.

Nocardia species are gram-positive environmental saprophytes, but some cause the infectious disease nocardiosis. The complete genomic sequence of Nocardia farcinica IFM 10152 has been determined, and analyses indicated the presence of two different RNA polymerase beta subunit genes, rpoB and rpoB2, in the genome (J. Ishikawa, A. Yamashita, Y. Mikami, Y. Hoshino, H. Kurita, K. Hotta, T. Shiba, and M. Hattori, Proc. Natl. Acad. Sci. USA 101:14925-14930, 2004). These genes share 88.8% identity at the nucleotide level. Moreover, comparison of their amino acid sequences with those of other bacterial RpoB proteins suggested that the nocardial RpoB protein is likely to be rifampin (RIF) sensitive, whereas RpoB2 protein contains substitutions at the RIF-binding region that are likely to confer RIF resistance. Southern analysis indicated that rpoB duplication is widespread in Nocardia species and is correlated with the RIF-resistant phenotype. The introduction of rpoB2 by using a newly developed Nocardia-Escherichia coli shuttle plasmid vector and transformation system conferred RIF resistance to Nocardia asteroides IFM 0319T, which has neither RIF resistance nor rpoB duplication. Furthermore, unmarked rpoB2 deletion mutants of N. farcinica IFM 10152 showed no significant resistance to RIF. These results indicated the contribution of rpoB2 to RIF resistance in Nocardia species. Since this is the first example of genetic engineering of the Nocardia genome, we believe that this study, as well as our determination of the N. farcinica genome sequence, will be a landmark in Nocardia genetics.

Amino Acid Sequence↗
PubMed1997

Recognition of a Nocardia transvalensis complex by resistance to aminoglycosides, including amikacin, and PCR-restriction fragment length polymorphism analysis.

Amikacin resistance, rare among nocardiae, was observed in 58 clinical isolates of nocardiae. All of these isolates hydrolyzed hypoxanthine, and 75 to 100% utilized citrate, D-galactose, and D-trehalose as sole carbon sources. Based on utilization of I-erythritol, D-glucitol, i-myo-inositol, D-mannitol, and ribitol and susceptibility to amoxicillin-clavulanic acid, the 58 isolates were separable into four groups. One group was negative for I-erythritol and ribitol and included all the isolates belonging to Nocardia asteroides complex antibiogram type IV. The remaining three groups were positive for I-erythritol and ribitol and were grouped within Nocardia transvalensis. The group that included the type strain was designated N. transvalensis sensu stricto, and the other two groups were designated new taxons 1 and 2. PCR-restriction fragment length polymorphism (RFLP) analysis of a 439-bp segment of the 65-kDa heat shock protein gene with XhoI and HinfI produced identical patterns for 53 (91%) and 58 (100%) isolates, respectively, and differentiated them from all other Nocardia taxa. NarI- and HaeIII-derived RFLP patterns clearly differentiated each of the four biochemically defined taxa. These four groups were also distinguishable by using the chromogenic substrates in Dade MicroScan test panels. By high-performance liquid chromatography, these isolates exhibited the same unique mycolic acid-ester elution patterns that differed from those of all other clinically significant nocardiae. Gas-liquid chromatographic analysis of fatty acids also produced similar patterns for all isolates that distinguished them from all other Nocardia taxa, but did not differentiate the four taxa within the complex. We propose the designation N. transvalensis complex for these four groups of nocardiae, pending further genetic evaluation.

Amikacin↗
PubMed1990

Cultivation of Nocardia spp. on chemically defined media for selective recovery of isolates from clinical specimens.

Isolation of Nocardia spp. from clinical specimens can be enhanced by the use of paraffin baiting, which relies on the selective ability of the organism to metabolize paraffin. We evaluated 44 Nocardia isolates, 18 group IV mycobacterial isolates, and 4 Streptomyces isolates for growth on blood agar (BA) and on carbon-free agar containing single or double substrates as follows: paraffin agar (PA), gelatin agar (GA), urea agar (UA), PA-gelatin (PG), and PA-urea (PU). The growth rates of Nocardia spp. on BA, PA, PU, and PG were similar; but 3-day-old colonies were larger on BA for 20 (45%) isolates. After longer incubations (7 to 14 days), some Nocardia colonies were larger on PA, PG and PU than they were on BA. Despite variable morphologies on BA, colonies on PA, PG, and PU were consistently smooth, creamy, and raised. Compared with growth on BA, the growth of mycobacteria was much slower on PA, PG, and PU, with poor growth on UA and GA. The growth of Streptomyces spp. was greatly enhanced on GA, PG, UA, and PU and was poorest on PA. Twelve sputum specimens seeded with Nocardia asteroides (10(4) CFU/ml) were inoculated onto BA and all chemically defined media. Nocardiae were recovered from 6 to 12 specimens grown on BA, GA, and UA; 11 of 12 specimens grown on PG; and 12 of 12 specimens grown on PA and PU. Only PA was able to suppress the growth of other microorganisms that were present in sputum specimens. These results suggest that chemically defined media containing PA may be useful for the selective isolation of Nocardia spp. from contaminated clinical specimens.

Culture Media↗
PubMed1994

Disseminated Nocardia farcinica infection in an AIDS patient.

This report describes an AIDS patient presenting with disseminated Nocardia farcinica infection diagnosed by percutaneous kidney biopsy. The isolate was initially identified as Nocardia asteroides. Though Nocardia asteroides remains sensitive to most antimicrobial agents, Nocardia farcinica is resistant to gentamicin, tobramycin and cephalosporins and is indistinguishable from Nocardia asteroides by regular laboratory methods. In view of the rising incidence of infections with Nocardia farcinica, third-generation cephalosporins should not be used in the initial management of Nocardia infections, and all isolates should be submitted for antibiotic susceptibility testing.

AIDS-Related Opportunistic Infections↗
PubMed1998

Clinicomicrobiological review of Nocardia keratitis.

PURPOSE: To present the clinical profile, laboratory results, and outcome of treatment in 16 patients with Nocardia keratitis. METHODS: A retrospective review of 16 culture-proven cases of Nocardia keratitis was done. Clinical and microbiologic data were analyzed. RESULTS: Nocardia constituted 1.7% of laboratory-confirmed bacterial keratitis and was seen predominantly in male subjects (13 of 16) with a mean age of 39.1 years. Although the predisposing factor was unknown in the majority, a definite history of trauma was present in four (25%) cases. Patchy stromal infiltrates were seen in 12 patients. Wreath pattern of infiltrates (six of 16) and hypopyon (nine of 16) were notable features. Nocardia was detectable in corneal scrapings of 10 patients with Gram stain and all patients with 1% acid-fast preparation (six of six). Nocardia asteroides was the causative agent in all except one (N. caviae). All isolates were sensitive to gentamicin; however, topical 30% sulfacetamide was the preferred drug for treatment. Favorable outcome (healed scar) was achieved in 11. CONCLUSION: Although Nocardia keratitis is a rare condition, a high index of clinical suspicion should be kept in agricultural workers or in patients with trauma who have patchy stromal infiltrates. Sulfonamides are the initial drug of choice, and gentamicin could be an effective alternative. If recognized early, Nocardia keratitis responds to medical treatment with good visual recovery.

Administration, Topical↗
PubMed1999

Nocardia salmonicida nom. rev., a fish pathogen.

An almost complete gene sequence of 16S rDNA of 'Nocardia salmonicida' strain JCM 4826T was determined following cloning and sequencing of the amplified gene. The sequence was aligned with those available for nocardiae and phylogenetic trees inferred using four tree-making algorithms. The organism and the type strain of Nocardia asteroides consistently formed a monophyletic clade with a distant sequence similarity of 97%. However, previous DNA relatedness experiments showed that strain JCM 4826T and Nocardia asteroides ATCC 19247T belong to different genomic species. The organism was also distinguished from representatives of all validly described species of Nocardia using a combination of phenotypic features. The polyphasic evidence showed that the strain merits recognition as a new species of the genus Nocardia. The name proposed for the new species is Nocardia salmonicida nom. rev.

Animals↗
PubMed2003

Nocardia puris sp. nov.

A bacterial isolate (IMMIB R-145(T)) from a human abscess was subjected to a polyphasic taxonomic study. Chemotaxonomic investigations revealed the isolate to have cell wall chemotype IV and mycolic acids consistent with characteristics of the genus NOCARDIA: Comparative 16S rRNA gene sequencing showed that the isolate constituted a distinct subline within the genus Nocardia, displaying greater than 1.7 % sequence divergence with established species. However, a DNA-DNA hybridization study demonstrated unambiguously that the isolate was genealogically distinct from closely related species, namely, Nocardia abscessus, Nocardia cyriacigeorgica and Nocardia farcinica, with which it showed high levels of 16S rDNA sequence similarity (97.8, 97.9 and 98.3 %, respectively). Based on phenotypic and phylogenetic data, it is proposed that this isolate be classified as a new species of the genus Nocardia, for which the name Nocardia puris (type strain IMMIB R-145(T)=DSM 44599(T)=NRRL B-24204(T)) is proposed.

Abscess↗