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PubMed1993

Highly presumptive identification of bacterial isolates associated with the recent Canada-wide mastitis epizootic as Nocardia farcinica.

A highly presumptive identification of Nocardia farcinica was made of 47 bacterial isolates. Fifteen isolates from Alberta, 9 from Ontario, and 2 each from New Brunswick, Newfoundland, and Nova Scotia were from clinical cases involved in the Canadian mastitis epizootic. Seventeen additional isolates from Alberta were recovered from farm milk bulk tanks from herds found to have cows involved in the epizootic. All isolates were shown by high-performance liquid chromatography to possess mycolic acids of a size consistent with the genus Nocardia. All isolates were resistant to a concentration of 5 micrograms/mL of mitomycin C. Forty-five isolates grew well and 2 showed reduced growth in the presence of 50 micrograms/mL of kanamycin acid sulfate. Forty-six isolates were resistant to 5-fluorouracil at a concentration of 20 micrograms/mL. All isolates were resistant to lysozyme. Resistance to these compounds supported the placement of the isolates in the genus Nocardia. Thirty-five isolates produced strong beta-galactosidase reactions and 12 showed weak reactions. The demonstration of beta-galactosidase activity further supports the identification of the isolates as nocardiae. Attempts to identify the bacteria to species by high-performance liquid chromatography of mycolic acid esters were frustrated, since two species of Nocardia were found to have indistinguishable mycolic acid patterns. The physiological and growth characteristics of the isolates were consistent with Nocardia farcinica.

Animals↗
PubMed1991

Acid and alkali as aids in differentiation of pathogenic Nocardia and for their isolation from clinical specimens.

The tolerance of Nocardia brasiliensis, Nocardia asteroides and Nocardia caviae to different concentrations of acids and alkalis was studied in this work. The purpose was to determine their use: (a) in the differentiation of species; (b) for decontamination of clinical materials during the isolation of pathogenic Nocardia. The results showed (1) that both 2 M NH3 and 0.05 M H2SO4 solutions are useful for differentiating species. They can also be used as a complementary method for identification. (2) That both 1 M NH3 and 0.05 M H2SO4 solutions were useful for decontamination of clinical materials during the isolation of pathogenic Nocardia.

Acetates↗
PubMed1980

Effect of route on inoculation on host resistance to Nocardia.

Virulent strains of Nocardia asteroides and Nocardia caviae were injected into mice by five different routes. When these organisms were grown to the same stage of growth in the same medium and otherwise prepared identically, it was found that they differed significantly in their ability to infect and kill the host, depending entirely upon the route of inoculation. Thus, N. caviae 112 was 30 times more virulent than N. asteroides GUH-2 when administered intranasally, whereas N. asteroides was at least 10 times more pathogenic than N. caviae when injected intravenously. They had similar degrees of virulence when given intraperitoneally. N. asteroides GUH-2 induced a more persistent and progressive infection than N. caviae 112 when injected into the footpads of mice; however, the latter strain was more lethal for the animals when given by this route. Different routes of infecting mice indicate a compartmentalization of the host response to different strains of nocardia. Therefore, the use of different strains of nocardia under carefully controlled and defined conditions should make it possible to dissect the nocardia-host interactions at the cellular levels.

Adipose Tissue↗
PubMed1993

Pneumonia caused by Nocardia nova and Aspergillus fumigatus after cardiac transplantation.

Nocardia nova, a newly established species of the Nocardia asteroides complex, has recently been characterized as a human pathogen. This report of a case of pneumonia caused by Nocardia nova and Aspergillus fumigatus in a patient after cardiac transplantation is the first reported infection caused by Nocardia nova following its detailed description. Accurate identification and susceptibility testing of the Nocardia nova isolate allowed successful oral therapy with clarithromycin when therapy with sulfisoxazole was not tolerated.

Amphotericin B↗
PubMed2000

Site-specific invasion of the basal ganglia by Nocardia asteroides GUH-2.

Nocardia asteroides GUH-2 (GUH-2) invades the nigrostriatal region of the brain in mice [15]. Selective dopaminergic neuronal dropout in the substantia nigra results in parkinsonian changes characterized by movement disorders responsive to L-dopa [15]. This is the only reported example of an experimental bacterial model for parkinsonism. Following i.v. inoculation of GUH-2 into the non-human primate Macaca fasicularius, the nocardiae preferentially invaded and grew within the basal ganglia (substantia nigra, caudate, putamen, and globus pallidus) often without inducing apparent inflammation. Reduced, limited growth of nocardiae occurred in the white matter of the cerebral cortex, medulla, and hippocampus, whereas neither significant adherence to nor growth within the meninges was observed. Twenty-four hours after injection, nocardial cells were found within capillary endothelial cells, the basal lamina, neurons, astroglia and in axonal extensions. The bacteria, in endothelial cells, were surrounded by a unit membrane, but in the basal lamina they appeared to be free and not membrane bound. After the organisms passed into the brain parenchyma, the nocardiae once again became surrounded by membrane, often being encapsulated by numerous layers with the innermost layer tightly adherence to the bacterial surface. There was a propensity for nocardial growth within and along myelinated axons, either with or without disruption to the surrounding myelin sheath. There was electron microscopic evidence that the nocardiae induced a neurodegenerative response especially in the substantia nigra region. Thus, the early interactions of GUH-2 within the primate brain appeared to be similar to those reported in the mouse.

Animals↗
PubMed2000

Infection caused by Nocardia farcinica: case report and review.

Nocardia farcinica is a rare Nocardia species causing localised and disseminated infections. A case of Nocardia farcinica infection is presented, and 52 cases previously reported in the literature are reviewed. The hosts usually had predisposing conditions (85%), and acquired the infection through the respiratory tract or skin; the infection then often spread to the brain, kidney, joints, bones and eyes. Pulmonary or pleural infections (43%), brain abscesses (30%) and wound infections (15%) which failed to respond to conventional antimicrobial therapy were the more frequent forms of infection. Nocardia farcinica was frequently isolated from pus (100% of samples), bronchial secretions (41%) and biopsy specimens (63%), but isolation from blood and urine, as in the case presented here, is rare. Antibiotic therapy was adequate in 61% of the patients in whom it was specified, the agents most frequently given being trimethoprim-sulfamethoxazole (54%), amikacin combined with imipenem (7%) and amoxicillin-clavulanate (7%). The high mortality (31%) can be attributed to the severe underlying diseases present, difficulties encountered in identifying the pathogen, inappropriate therapy and late initiation of therapy. Although an infrequent pathogen, Nocardia farcinica should be kept in mind as a cause of infection especially in immunosuppressed patients with indolent infections not responding to third-generation cephalosporins.

Aged↗
PubMedDate not supplied

Biochemical identification and molecular characterization (PCR-RFLP) of Nocardia isolates from sputum.

BACKGROUND: Nocardia identification has been based on biochemical and morphological characteristics. However, molecular biology techniques allow a better characterization of species and biotypes that are related to invasive diseases. METHODS: Twelve isolates of Nocardia spp. were obtained from sputum of patients with tuberculosis under retreatment. Identification was done based on morphological characteristics, biochemical tests (casein, tyrosine, xanthine, gelatin, and urea) and molecular biology techniques (PCR-RFLP) using restriction enzymes MspI, HinfI, BsaHI, HaeIII and BstEII. RESULTS: Biochemical tests identified the 12 isolates as Nocardia asteroides. PCR-RFLP technique identified nine isolates to species and biotype level: five as N. asteroides type II, two as N. asteroides type VI, and two as N. asteroides type I. The remaining three isolates were identified as follows: one to species level as N. farcinica and two at genus level as Nocardia sp. CONCLUSIONS: Significant statistical differences between the use of traditional techniques and PCR-RFLP were not found at genus level, but there were important differences at species and biotype level. Biochemical tests identified correctly the actinomycete isolates as belonging to Nocardia genus, but at N. asteroides complex level were not able to discern among their different species. PCR-RFLP is a rapid, non-expensive, and reliable method that allows to discriminate the N. asteroides complex species, identifying biotypes related to invasive disease. Our results suggest that the hospital environment was not a contamination source.

Actinobacteria↗
PubMed2006

Confocal microscopy for Nocardia keratitis.

PURPOSE: To assess the role of confocal microscopy for in vivo detection of Nocardia in patients with microbial keratitis. DESIGN: Retrospective interventional case series. PARTICIPANTS: Three patients with microbiologically proven Nocardia keratitis. INTERVENTION: Confocal microscopy. METHODS: We performed confocal microscopy in microbiologically proven cases of Nocardia asteroides keratitis. A masked observer examined the images. For better understanding of the images, we also performed confocal microscopy on a blood agar culture plate with Nocardia growth. RESULTS: Confocal microscopy of infiltrated cornea revealed highly reflective, short, thin branching filaments with bright inflammatory cells in the background. The filaments were seen clearly at the edge of the infiltrate. In scans with faint images, these filaments became more visible on inversion of bright and dark components. Confocal microscopy of cultured organisms also revealed filamentous beaded structures with a morphology identical to that of those seen in vivo. CONCLUSION: Nocardia, a filamentous bacterium, produces a distinct image on confocal microscopy. This in vivo examination technique may be useful in cases of deep-seated infiltrates where routine microbiology workup does not yield positive results.

Adult↗
PubMed1997

Transmission of nocardiosis and molecular typing of Nocardia species: a short review.

Nocardia species are ubiquitous in the environment and may be found in the soil. They are generally responsible for sporadic pulmonary diseases acquired by inhalation of spores, with secondary localizations in the central nervous system and subcutaneous tissues. There is no absolute evidence for person to person transmission. Presumptive outbreaks of nocardiosis were observed in immunocompromised patients, more frequently in kidney transplant patients than in cardiac transplant patients. Nocardia spp., being present in dust particles, closure and disinfection of the transplantation unit with formaldehyde arrested the sequence of cases of nocardiosis. The original sources of the Nocardia sp. remain doubtful. Other possible sources of contamination are other patients, medical staff and the hospital environment. The first studies of Nocardia spp. typing were based on the detection of extracellular antigens, on the susceptibility of actinomycete strains to killer yeasts, and on the biochemical profiles with fluorogenic substrate. The use of molecular typing techniques have given very promising results. Analysis of plasmid profiles is an interesting way to compare the identity of isolates, although the reliability of this method depends of the presence of plasmids in the isolates. Other typing methods, including analysis of restriction length fragment polymorphism of total DNA, ribosomal DNA fingerprinting, require further investigations to evaluate their discriminating power or to be easily interpretable, whereas a random amplified polymorphic DNA (RAPD) assay was successful for epidemiological purposes. Progress in epidemiological analysis of cases of nocardiosis will be consistent when an improved diagnosis of this infection (molecular and serological diagnosis) will be available, when the genetic diversity of Nocardia spp. isolates will be better known, and when molecular typing, that hold promise in complementing investigations of outbreak of these infections, will be systematically performed when an abnormal increase of cases of nocardiosis in a population with risk factors is observed.

Disease Outbreaks↗
PubMed2002

Intracranial Nocardia dissemination during minocycline therapy.

Nocardia species is a well-known pathogen in immunocompromised hosts, including renal transplant recipients. Primary pulmonary infection can disseminate to other organs and recommended first-line therapy is high-dose trimethoprim/sulfamethoxazole (TMP/SMX). We report two cases of primary pulmonary Nocardia sp. in immunosuppressed patients who were treated with minocycline, a second-line drug. During treatment with minocycline, both patients developed central nervous system (CNS) lesions of Nocardia sp. and were then treated with TMP/SMX with resolution of disease. The literature on Nocardia and treatment with minocycline is reviewed. Treatment of pulmonary Nocardia sp. with 200 mg minocycline daily is not adequate to prevent disseminated CNS disease.

Anti-Bacterial Agents↗
PubMedDate not supplied

Serological reactions to Nocardia antigens.

Sera from 23 patients with nocardiosis were tested for the presence of precipitating antibodies against an extract of Nocardia asteroides. Sera from nine of 20 patients infected with Nocardia asteroides and one of three sera from patients with Nocardia brasiliensis produced one to three precipitin lines with the antigen. Sera from eight of 55 patients with tuberculosis and 11 of 13 patients with leprosy also contained Nocardia precipitins. None of 33 sera from patients with cryptococcosis, blastomycosis, actinomycosis, histoplasmosis, coccidioidomycosis, mucormycosis or candidiasis contained Norcardia antibodies. None of the sera from ten patients infected with Staphylococcus aureus, ten patients infected with Pseudomonas, or 16 sera from uninfected patients contained Nocardia precipitins.

Actinomycosis↗
PubMed2001

Topical bactrim versus trimethoprim and sulfonamide against nocardia keratitis.

PURPOSE: The conventional treatment of Nocardia keratitis is with topical sulfonamides. Recently, topical trimethoprim and sulfamethoxazole (Bactrim) has been suggested as treatment. This study compares the in vitro efficacy against Nocardia asteroides of Bactrim and various ratios of trimethoprim and a sulfonamide. METHODS: Antibiotic disks were soaked with various ratios of trimethoprim and sulfacetamide sodium. They contained trimethoprim alone, sulfacetamide sodium alone, and both trimethoprim and sulfacetamide sodium at ratios of 1:40, 1:20, and 1:5. Disks containing Bactrim were also prepared. Each disk was placed on blood agar plates streaked with N. asteroides. The plates were incubated at 37 degrees C for 72 hours and then examined. RESULTS: Trimethoprim alone showed minimal effect. Sulfacetamide sodium alone had a clearance zone of 12 mm. The plates of trimethoprim and sulfacetamide sodium at ratios of 1:40, 1:20, and 1:5 had clearance zones of 14 mm, 17 mm, and 27 mm, respectively. Bactrim had a clearance zone of 70 mm. CONCLUSION: Trimethoprim or sulfacetamide sodium alone is not as effective as both drugs together. As the ratio of the two drugs was changed, potency differed against Nocardia organisms. Bactrim was the most effective antibiotic against Nocardia organisms. It should be the recommended agent for the treatment of Nocardia keratitis.

Administration, Topical↗
PubMed1976

Free mycolic acids as criteria in the classification of Nocardia and the 'rhodochrous' complex.

The methyl esters of free mycolic acids from representative strains of Nocardia asteroides, N. brasiliensis, N. caviae and the 'rhodochrous' complex were subjected to detailed mass spectral analysis. The anhydromycolic esters of the Nocardia strains consisted of homologous series containing from zero to three double bonds, with the main components of the parent mycolic acids centred on C52 to C54 (range C46 to C58). The anhydromycolates from one rhodochrous strain, Nocardia opaca, had a molecular weight range similar to the nocardiae (C46 to C57) but the remaining rhodochrous strains gave an homologous series of anhydromycolates containing from zero to two double bonds, with the main components of the parent mycolic acids centred on C38, C42, C44 or C46 (total range from C34 to C50). The mycolic acids from the rhodochrous strains with chain lengths centred around C40 form a group intermediate in size between corynomycolic acids (centred around C32) and nocardomycolic acids (centred around C50). These data weaken the case for retaining the 'rhodochrous' complex in the genus Mycobacterium, and also show that many rhodochrous strains can be distinguished from true nocardiae and corynebacteria. These results confirm the value of lipid characters in the classification of these organisms.

Esters↗
PubMed2006

Clinical and laboratory features of the Nocardia spp. based on current molecular taxonomy.

The recent explosion of newly described species of Nocardia results from the impact in the last decade of newer molecular technology, including PCR restriction enzyme analysis and 16S rRNA sequencing. These molecular techniques have revolutionized the identification of the nocardiae by providing rapid and accurate identification of recognized nocardiae and, at the same time, revealing new species and a number of yet-to-be-described species. There are currently more than 30 species of nocardiae of human clinical significance, with the majority of isolates being N. nova complex, N. abscessus, N. transvalensis complex, N. farcinica, N. asteroides type VI (N. cyriacigeorgica), and N. brasiliensis. These species cause a wide variety of diseases and have variable drug susceptibilities. Accurate identification often requires referral to a reference laboratory with molecular capabilities, as many newer species are genetically distinct from established species yet have few or no distinguishing phenotypic characteristics. Correct identification is important in deciding the clinical relevance of a species and in the clinical management and treatment of patients with nocardial disease. This review characterizes the currently known pathogenic species of Nocardia, including clinical disease, drug susceptibility, and methods of identification.

Anti-Bacterial Agents↗
PubMed1994

Nocardia species: host-parasite relationships.

The nocardiae are bacteria belonging to the aerobic actinomycetes. They are an important part of the normal soil microflora worldwide. The type species, Nocardia asteroides, and N. brasiliensis, N. farcinica, N. otitidiscaviarum, N. nova, and N. transvalensis cause a variety of diseases in both normal and immunocompromised humans and animals. The mechanisms of pathogenesis are complex, not fully understood, and include the capacity to evade or neutralize the myriad microbicidal activities of the host. The relative virulence of N. asteroides correlates with the ability to inhibit phagosome-lysosome fusion in phagocytes; to neutralize phagosomal acidification; to detoxify the microbicidal products of oxidative metabolism; to modify phagocyte function; to grow within phagocytic cells; and to attach to, penetrate, and grow within host cells. Both activated macrophages and immunologically specific T lymphocytes constitute the major mechanisms for host resistance to nocardial infection, whereas B lymphocytes and humoral immunity do not appear to be as important in protecting the host. Thus, the nocardiae are facultative intracellular pathogens that can persist within the host, probably in a cryptic form (L-form), for life. Silent invasion of brain cells by some Nocardia strains can induce neurodegeneration in experimental animals; however, the role of nocardiae in neurodegenerative diseases in humans needs to be investigated.

AIDS-Related Opportunistic Infections↗
PubMed1991

Clinical and laboratory features of Nocardia nova.

Recent studies have shown that Nocardia asteroides isolates have five major antibiotic resistance patterns; one of these patterns identifies isolates of Nocardia farcinica. In the current study, we investigated a second pattern characterized by susceptibility to ampicillin and erythromycin. This pattern was seen in 17% of 223 clinical isolates identified by standard techniques as N. asteroides and associated with diseases typical for nocardiae. Biochemically, isolates with this drug pattern were relatively homogeneous and identical to the type strain and previous descriptions of Nocardia nova. The strains studied were unique among nocardiae in having both alpha- and beta-esterase activity (85 and 95%, respectively). However, the arylsulfatase activity at 14 days (75%) and antimicrobial susceptibility patterns, including susceptibility to erythromycin (100%), were the only routinely available methods that would separate N. nova strains from other members of N. asteroides. N. asteroides should be considered a complex because current clinical identification schemes include isolates of N. farcinica and N. nova and may well include additional species. This is the first detailed description of N. nova as a pathogen in humans.

Ampicillin Resistance↗
PubMed1984

Nocardia in soils of southeastern Spain: abundance, distribution, and chemical characterisation.

Actinomycetes belonging to the genus Nocardia were isolated from the surface horizon of 15 out of 46 soil samples examined. All the nocardiae strains isolated contained mycolic acids and saturated and unsaturated straight chain fatty acids (from 12 to 18 carbon atoms) and tuberculostearic acid and were biochemically identified as members of the Nocardia asteroides complex. Nocardiae were detected in alluvial, brown, and serosem great soil groups, but not in calcic brown, solontchack, and regosol great soil groups. Numbers of nocardiae isolated varied from 5.12 X 10(2) to 1.21 X 10(4) colony-forming units per gram of dry weight, and they were statistically correlated with the carbon content (percent C) of the soil. Soil samples were, in general, very dry.

Nocardia↗
PubMed1975

[The application of chorioallantois membranes of chicken embryos for the virulence determination of Nocardia asteroides (author's transl)].

The pathogenicity of Nocardia asteroides and other strains of different Nocardia species against chicken embryos was investigated. The strains were inoculated on the chorioallantois membrane of embryonated eggs and the resulting lesions were judged. 55 Nocardia asteroides strains and some strains of the species N. brasiliensis, N. leishmanii, N. caviae, N. (Actinomadura) madurae, N. caprae, N. rubra, N. pellegrini, N. corallina and N. polychromogenes were studied. 47 strains of the species N. asteroides were pathogenic, 2 apathogenic and 6 strains showed doubtful results. All the investigated 5 strains of the species N. brasiliensis, N. leishmanii, N. caviae and N. (Actinomadura) madurae, provoked typical lesions on the chorioallantois membrane. The other investigated strains were apathogenic. With this, described test it is possible to distinguish between pathogenic and apathogenic Nocardia strains, which is indeed important for the diagnosis of Nocardia infection.

Animals↗