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Infections due to Nocardia transvalensis: clinical spectrum and antimicrobial therapy.

Nocardia transvalensis, a rare Nocardia species, has previously been recognized as a cause of actinomycotic mycetoma. In a retrospective review of N. transvalensis isolates referred to the Centers for Disease Control (Atlanta) during the period January 1981 through January 1990, we identified 15 patient isolates. Four N. transvalensis isolates originated from one Australian reference laboratory; one patient's isolate that was identified by the Australian laboratory but that was not received at the Centers for Disease Control was also included in our study. A review of the cases of these 16 patients found that N. transvalensis caused infection in 10 patients and colonization in two patients. Six (75%) of eight patients with primary pulmonary or disseminated N. transvalensis infections had an underlying immunologic disorder or were receiving immunosuppressive therapy; three patients with disseminated infection died. All nine infected patients for whom specific antimicrobial therapy was prescribed received trimethoprim-sulfamethoxazole. Results of in vitro antimicrobial susceptibility tests of 11 N. transvalensis isolates revealed increased antimicrobial resistance to amikacin and other drugs when compared with that of other Nocardia species. Severely immunocompromised patients are predisposed to N. transvalensis pneumonia or disseminated infection, and the lung may be the portal of entry.

Adolescent↗

Disseminated and cerebral infection due to Nocardia farcinica: diagnosis by blood culture and cure with antibiotics alone.

Systemic infections with Nocardia species continue to be a serious threat to immunosuppressed hosts. Diagnosis of these infections can be difficult despite their known tendency for cerebral and subcutaneous involvement. We describe a patient who presented with nonspecific constitutional symptoms and was found to have subcutaneous and cerebral abscesses due to Nocardia farcinica. In addition, a blood culture yielded the organism. The patient responded remarkably to oral therapy; resolution of the cerebral disease was observed on serial magnetic resonance images. We discuss the important clinical features on N. farcinica infection, the rarity of positive blood cultures, and the importance of susceptibility testing of Nocardia species in selecting drug therapy.

Anti-Bacterial Agents↗

In-vitro activity of flomoxef, a new oxacephem group antibiotic, against Nocardia in comparison with other cephalosporins.

The susceptibility of 113 strains of pathogenic Nocardia, N. asteroides, N. farcinica, N. nova, N. brasiliensis and N. otitidiscaviarum to a new oxacephem antibiotic flomoxef was determined by an agar dilution method in comparison with those of 13 other cephalosporins. Flomoxef was two to 50 times more active against these pathogenic Nocardia than other cephalopsorins tested. However, there were differences in susceptibility to this antibiotic among these Nocardia strains. N. asteroides was the most sensitive species, followed by N. farcinica and N. nova. N. brasiliensis was moderately sensitive and N. otitidiscaviarum was resistant.

Cephalosporins↗

Nocardia paucivorans sp. nov.

Chemotaxonomic and 16S rDNA sequence analyses of an isolate from the sputa and bronchial secretions of a patient with chronic lung disease clearly demonstrated that it belongs to the genus Nocardia. DNA-DNA hybridization data, as well as the biochemical characteristics of the isolate, indicate that it belongs to a new species that differs from previously described members of the genus Nocardia. The name Nocardia paucivorans sp. nov. is proposed for this isolate and is represented by strain IMMIB D-1632T (= DSM 44386T).

Bacterial Typing Techniques↗

Nocardia cyriacigeorgici sp. nov..

Chemotaxonomic and 16S rRNA gene sequence analyses of an isolate from the bronchial secretions of a patient with chronic bronchitis demonstrated clearly that it belongs to the genus Nocardia. The 16S rRNA gene sequence data, as well as the biochemical characteristics of the isolate, indicated that it belongs to a new species that differs from previously described members of the genus Nocardia. The name Nocardia cyriacigeorgici sp. nov. is proposed for this isolate, and is represented by strain IMMIB D-1627T (= DSM 44484T).

Base Composition↗

Immunodiffusion studies of some Nocardia strains.

Forty-three strains of Nocardia, one of Actinomadura and two of Nocardiopsis were studied using the comparative immunodiffusion technique. Three reference precipitation systems were employed: one represented Nocardia asteroides N10, one N. asteroides ATCC 19247, and one N. otitidis-caviarum ATCC 14629. One tight cluster was formed by the N. otitidis-caviarum strains and another tight cluster was formed by some of the N. asteroides strains studied. However, other strains of N. asteroides were distinct from the latter cluster. Furthermore, N. asteroides ATCC 19247, which is the type strain, differed from most ot the N. asteroides strains tested. Strains of the species N. asteroides, N. brasiliensis, N. farcinica and N. otitidis-caviarum were found to be closely related, while N. amarae strains differed slightly from this group. The strains referred to Actinomadura and Nocardiopsis were clearly distinct from the three Nocardia reference strains; nevertheless, three antigens common to these genera were revealed.

Antigens, Bacterial↗

Differentiation between the genera Mycobacterium, Rhodococcus and Nocardia by susceptibility to 5-fluorouracil.

A test for susceptibility to 5-fluorouracil was useful for differentiating between species of rapidly growing mycobacteria, and for differentiating the genus Rhodococcus from the genus Nocardia. The majority of rhodococci tested were susceptible to 5-fluorouracil (20 micrograms ml-1), whereas the majority of nocardiae tested were resistant to it. Strains of Nocardia asteroides sensu stricto could be divided into two subgroups by their reaction to 5-fluorouracil.

Fluorouracil↗

Occurrence of plasmids in pathogenic strains of Nocardia.

The purpose of the present study was to determine the relative distribution of plasmids in 87 clinical isolates of Nocardia, belonging to the five major pathogenic species. A correlation between plasmid content and the site of infection within the host, resistance to antibiotics and enzymic profiles was also investigated. The plasmid extraction procedure of Kado and Liu was used. Electrophoretic analysis revealed one-to-four plasmid bands, ranging in size from <8 to >50 kb, in 27 strains (31%). Based on the number of isolates tested, the incidence of plasmid-bearing strains was significantly higher among N. farcinica than N. asteroides strains. Within N. farcinica, the incidence of plasmids was higher among strains isolated in the Paris area than in strains isolated elsewhere, such as in the French provinces or outside France. A statistically significant correlation was demonstrated between the cutaneous localisation of infections and the incidence of plasmid-bearing strains. The presence of plasmids in nocardiae could not be associated with specific phenotypic traits such as resistance to antibiotics or enzymic activity. The fact that the majority of Nocardia clinical isolates (60 of 87) did not contain plasmids suggests that plasmids are not involved directly in virulence and that there is no selective pressure for plasmid acquisition.

Anti-Bacterial Agents↗

Nocardia asiatica sp. nov., isolated from patients with nocardiosis in Japan and clinical specimens from Thailand.

Five strains isolated from two patients with nocardiosis in Japan and three clinical samples from Thailand were found to have morphological, biochemical and chemotaxonomic properties consistent with their classification in the genus Nocardia. DNA-DNA hybridization, coupled with sequence analysis of 16S rDNA, indicated that these strains belong to a novel species of the genus Nocardia, named Nocardia asiatica sp. nov. because the isolation sites were in Asian countries; the type strain is IFM 0245T (=NBRC 100129T=JCM 11892T=DSM 44668T).

DNA, Ribosomal↗

In vitro susceptibility of Nocardia spp. to a new fluoroquinolone, tosufloxacin (T-3262).

The in vitro activity of a new fluoroquinolone, tosufloxacin (T-3262), against 111 pathogenic Nocardia strains was studied by an agar dilution method and compared with the activities of other fluoroquinolones. All strains were susceptible to tosufloxacin, and the drug was 2 to 20 times more active than four other quinolones tested. Nocardia farcinica was the Nocardia species most susceptible to tosufloxacin.

4-Quinolones↗

RAPID DIFFERENTIATION BETWEEN NOCARDIA AND STREPTOMYCES BY PAPER CHROMATOGRAPHY OF WHOLE-CELL HYDROLYSATES.

Whole-cell hydrolysates were prepared from 58 strains of nocardiae and streptomycetes. Strains morphologically intermediate between the two genera and morphological variants of the same strains were included. Paper chromatograms made from the whole-cell hydrolysates clearly demonstrated meso-diaminopimelic acid as a major constituent of cultures of Nocardia spp., and LL-diaminopimelic acid as a major constituent of cultures of Streptomyces spp. In cultures of ten strains of N. madurae and of three of N. pelletieri, meso-diaminopimelic acid predominated, thereby supporting the assignment of these species to the genus Nocardia.

Actinomycetales↗

Adoptive transfer of immunity to Nocardia asteroides in nude mice.

Nude mice on a BALB/c background were adoptively transferred with unprimed spleen cells, Nocardia-primed spleen cells, or Nocardia-primed splenic T lymphocytes from syngeneic, heterozygous (nu/+) littermates. Two days later, these recipient mice and unmanipulated (control) nude mice were infected intravenously with a 50% lethal dose of Nocardia asteroides GUH-2 from an early stationary-phase culture. Antibody titers, spleen weights, percent mortality, and organ clearance of the microorganisms were measured at 3 h to 28 days after infection. Adoptively transferred nude mice had larger spleens and greater titers of anti-nocardial antibody 7 to 28 days after infection as compared with control nude mice. Adoptive transfer with either primed spleen cells or primed splenic T lymphocytes enhanced both the survival of recipient nude mice and their ability to eliminate N. asteroides from the liver and spleen. These data indicate that adoptive immunity to infection with N. asteroides can be transferred with either specifically primed spleen cells or splenic T lymphocytes. Thus, it appears that cell-mediated immunity and T lymphocytes are of uppermost importance in host resistance to nocardial infection.

Animals↗

Cytoplasmic antigens from Nocardia elicting a specific delayed hypersensitivity.

Purified cytoplasmic extracts from Nocardia asteroides and N. brasiliensis elicit delayed hypersensitivity in Nocardia-sensitized guinea pigs. The differences in skin reactivity clearly show that it is possible to distinguish between different Nocardia species. When peritoneal exudate cells from the latter animals were obtained and treated with the purified cytoplasmic extracts, their migration was inhibited to a significant degree only by means of the homologous antigen. A mild delayed reactivity was observed when the cytoplasmic antigens were used as skin test materials on animals sensitized with BCG. On the other hand, no inhibition of migration was observed when peritoneal exudate cells from BCG-sensitized guinea pigs were exposed to the cytoplasmic antigens.

Animals↗

Monoclonal antibodies demonstrate that superoxide dismutase contributes to protection of Nocardia asteroides within the intact host.

The importance of superoxide dismutase (SOD) in protecting cells of Nocardia asteroides from the oxidative killing mechanisms within the intact murine host was determined. Murine monoclonal antibodies specific for nocardial SOD and for another nocardial antigen were prepared. Both antibodies adhered to cell surface antigens, as shown by fluorescence-labeled-antibody staining. The anti-nocardial SOD antibody inhibited the effect of nocardial SOD on superoxide generated in vitro. Cells of N. asteroides GUH-2 in log phase of growth were incubated with monoclonal anti-nocardial SOD, another monoclonal antinocardial antibody (not reactive with SOD), or phosphate-buffered saline and then injected intravenously into mice. Total recovery of CFU and inhibition of growth were determined at 3, 24, and 48 h after infection. The brains, kidneys, spleens, lungs, and livers were weighed, homogenized, and plated in order to quantitate the number of organisms in each organ at each time period. There was an initial killing followed by enhanced clearance of N. asteroides from the lungs and livers of mice which had received anti-SOD antibody-treated nocardiae. There was also enhanced early killing in the spleen. At 48 h, there were fewer organisms recovered from the brains, kidneys, and livers of mice which had received anti-SOD antibody-treated nocardia. This was not true for mice which had received antinocardial antibody not specific for SOD. The data demonstrate that surface-associated SOD protects N. asteroides for oxidative killing in vivo during all stages of infection.

Animals↗

Ultrastructural analysis of attachment to and penetration of capillaries in the murine pons, midbrain, thalamus, and hypothalamus by Nocardia asteroides.

The attachment to and penetration of endothelial cells in the pons and midbrain (especially the substantia nigra) regions of the brains of BALB/c mice by log-phase Nocardia asteroides GUH-2 cells were determined by both scanning and transmission electron microscopic analysis. Within 15 min after exposure, the nocardiae attached to the surface of the endothelial cell membrane. This attachment occurred primarily at the growing tip of the nocardial filament, and the outermost layer of the nocardial cell wall had regions (electron-dense areas) that bound firmly to the cytoplasmic membrane of the host cell. There appeared to be specificity for this binding localized within the capillaries and arterioles because some regions had large numbers of bacteria bound, whereas adjacent areas had no bacterial cells. Nocardial filaments that attached by the apex induced a cuplike deformation of the endothelial cell membrane. This was followed by a rapid penetration of the endothelial cell so that within 25 min many of the bacteria were internalized within the host cell. These internalized bacteria remained within vesicles, and there was no ultrastructural evidence of damage to the nocardial cell during this process. Heat-killed GUH-2 cells still attached to endothelial surfaces (at a reduced frequency), but they did not penetrate into the endothelial cell. These data suggest that brain-invasive nocardiae possess both an adhesin for attachment to the membrane of endothelial cells and an invasion factor that promotes nocardial penetration of these cells.

Animals↗

Filament tip-associated antigens involved in adherence to and invasion of murine pulmonary epithelial cells in vivo and HeLa cells in vitro by Nocardia asteroides.

The interactions of Nocardia asteroides GUH-2 with pulmonary epithelial cells of C57BL/6 mice and with HeLa cells were studied. Electron microscopy demonstrated that only the tips of log-phase cells penetrated pulmonary epithelial cells following intranasal administration, and nocardiae were recovered from the brain. Coccobacillary cells neither invaded nor disseminated. Serum from immunized mice (IMS) decreased attachment to and penetration of pulmonary epithelial cell surfaces by log-phase GUH-2 and inhibited spread to the brain. IMS was adsorbed against stationary-phase cells. Western immunoblots suggested that this adsorbed IMS was reactive primarily with 43- and 62-kDa proteins. Immunofluorescence showed that adsorbed IMS preferentially labeled the tips of log-phase GUH-2 cells. Since this IMS was reactive to culture filtrate antigens, several of these proteins were cut from gels, and mice were immunized. Sera against 62-, 55-, 43-, 36-, 31-, and 25-kDa antigens were obtained. The antisera against the 43- and 36-kDa proteins labeled the filament tips of GUH-2 cells. Only the antiserum against the 43-kDa antigen increased pulmonary clearance, inhibited apical attachment to and penetration of pulmonary epithelial cells, and prevented spread to the brain. An in vitro model with HeLa cells demonstrated that the tips of log-phase cells of GUH-2 adhered to and penetrated the surface of HeLa cells. Invasion assays with amikacin treatment demonstrated that nocardiae were internalized. Adsorbed IMS blocked attachment to and invasion of these cells. These data suggested that a filament tip-associated 43-kDa protein was involved in attachment to and invasion of pulmonary epithelial cells and HeLa cells by N. asteroides GUH-2.

Animals↗

Comparison of the developmental cycles of some members of the genus Nocardia.

Adams, James N. (University of Georgia, Athens) and Norvel M. McClung. Comparison of the developmental cycles of some members of the genus Nocardia. J. Bacteriol. 84:206-216. 1962.-A staining technique specific for cell walls was used to determine the characteristic development of Nocardia rubra, N. erythropolis, N. asteroides, and N. canicruria comb. nov. When inoculated on a fresh medium, these organisms were observed to germinate, with the production of one or more germ tubes from coccoid, ovoid, and short bacillary cells. Upon continued incubation, the germ tubes elongated to form filaments from which branches could be formed. Two other mechanisms of branching were noted. One was a result of multiple germination of cells and the other a result of single or multiple germination of short chains of cells. Both of these mechanisms could be readily differentiated from true branching. Mycelial formation varied in extent among the species studied and was governed, in part, by the types of branching which an organism exhibited. After the phase of branching development has been completed, fragmentation of the filaments and branches occurred as a result of the separation of the corresponding filament fragments following the random deposition of septa along the lengths of the cells. As the culture age increased, the separating filament fragments became shorter until they ultimately reached sizes like those of cells found in the inoculum. The observed developmental cycles of the genus Nocardia were compared to those which have been described for the genera Mycobacterium and Streptomyces, and the taxonomic implications of the differences between these developmental cycles was discussed.

Mycobacterium↗

Detection of metabolites by frequency-pulsed electron capture gas-liquid chromatography in serum and cerebrospinal fluid of a patient with Nocardia infection.

Serum (SR) and cerebrospinal fluid (CSF) from a patient suspected of having tuberculous meningitis were submitted to our laboratory for analysis by frequency-pulsed electron capture gas-liquid chromatography (FPEC GLC). The samples were tested for the presence of carboxylic acids, alcohols, hydroxy acids, and amines by methods described previously (C. C. Alley, J. B. Brooks, and D. S. Kellogg, Jr., J. Clin. Microbiol. 9:97-102, 1977; J. B. Brooks, C. C. Alley, and J. A. Liddle, Anal. Chem. 46:1930-1934, 1974; J. B. Brooks, D. S. Kellogg, Jr., M. E. Shepherd, and C. C. Alley, J. Clin. Microbiol. 11:45-51, 1980; J. B. Brooks, D. S. Kellogg, Jr., M. E. Shepherd, and C. C. Alley, J. Clin. Microbiol. 11:52-58, 1980). The results were different from previous FPEC GLC profiles of SR and CSF from patients with known tuberculous meningitis. Both the SR and CSF contained several unidentified compounds that were not previously detected in tuberculous meningitis or any of our other studies of body fluids. Nocardia brasiliensis was later isolated from the patient. Detection of these metabolites by FPEC GLC could prove to be useful for rapid diagnosis of Nocardia disease, and their identification will provide a better understanding of metabolites produced by Nocardia sp. in vivo.

Amines↗