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).

Identification of nocardia species by restriction endonuclease analysis of an amplified portion of the 16S rRNA gene

Identification of clinical isolates of Nocardia to the species level is important for defining the spectrum of disease produced by each species and for predicting antimicrobial susceptibility. We evaluated the usefulness of PCR amplification of a portion of the Nocardia 16S rRNA gene and subsequent restriction endonuclease analysis (REA) for species identification. Unique restriction fragment length polymorphism (RFLP) patterns were found for Nocardia sp. type strains (except for the N. asteroides type strain) and representative isolates of the drug pattern types of Nocardia asteroides (except for N. asteroides drug pattern type IV, which gave inconsistent amplification). A variant RFLP pattern for Nocardia nova was also observed. Twenty-eight clinical isolates were evaluated both by traditional biochemical identification and by amplification and REA of portions of the 16S rRNA gene and the 65-kDa heat shock protein (HSP) gene. There was complete agreement among the three methods on identification of 24 of these isolates. One isolate gave a 16S rRNA RFLP pattern consistent with the biochemical identification but was not identifiable by its HSP gene RFLP patterns. Three isolates gave 16S rRNA RFLP patterns which were inconsistent with the identification obtained by both biochemical tests and HSP gene RFLP; sequence analysis suggested that two of these isolates may belong to undefined species. The PCR and REA technique described appears useful both for the identification of clinical isolates of Nocardia and for the detection of new or unusual species.

Hypercalcemia associated with granulomatous disease in a cat

A 6-year-old cat was examined because of recurrence of a draining mass involving skin and subcutaneous tissues of the caudoventral aspect of the abdomen. Previous treatment included administration of antimicrobial drugs and corticosteroids and surgical excision. Atypical mycobacteria were seen during cytologic examination of biopsy specimens of the mass; Nocardia sp was cultured. While hospitalized, the cat developed hypercalcemia and was found to have high serum calcitriol concentrations. Treatment consisted of administration of ciprofloxacin and trimethoprim-sulfadiazine because of the infection and administration of sodium chloride solution, furosemide, and calcitonin because of the hypercalcemia. The cat recovered.

Antimicrobial susceptibility of Nocardia nova isolated from five cats with nocardiosis

From 1992 through 1997, 5 cats were admitted to the hospital because of chronic, nonhealing lesions containing draining tracts. Exudate from 2 of the 5 cats contained macroscopically visible granules. On the basis of cytologic findings, lesions were described as pyogranulomatous. Degenerative neutrophils and activated macrophages, along with slender, branching, gram-positive, partially acid-fast microorganisms, were observed in stained smears of exudates obtained from all 5 affected cats. Nocardia nova was found in pure culture from all affected sites. Most isolates were susceptible to ampicillin, aminoglycosides (ie, amikacin, kanamycin), tetracyclines (ie, doxycycline, minocycline), macrolides (ie, erythromycin, clarithromycin), imipenem, sulfisoxazole, and trimethoprim-sulfamethoxazole. Other antimicrobials were less effective, and these included amoxicillin-clavulanic acid, the cephalosporins (ie, cefotaxime, ceftizoxime, ceftriaxone), and some aminoglycosides (ie, gentamicin, tobramycin). Four of the 5 cats were successfully treated, 3 with a trimethoprim-sulfonamide combination, and 1 with clarithromycin. The outcome of treatment of the fifth cat is unknown. Findings in this report may be useful in diagnosis and treatment of nocardiosis caused by N nova in cats.

Nocardia nova causing pulmonary nocardiosis of black crakes (Limnocorax flavirostra)

Natural nocardial infection has been reported in many different species including mammals and fish, but reports in birds remain uncommon. Eight juvenile Black Crakes (Limnocoraxflavirostra) died unexpectedly at the Basle Zoo. Necropsy revealed disseminated white, firm nodules, 1-3 mm in diameter, throughout the lung parenchyma. Histologically, the lungs contained multiple, often confluent granulomas with central necrosis. Delicate, gram-positive, 0.5- to 1.0-microm-wide, branching, occasionally beaded, filamentous organisms were visible in necrotic centers. These organisms were acid fast when stained with Fite-Faraco. No histologic lesions were seen in other organs. Nocardia nova was isolated from liver, spleen, kidney, and lung. Granulomatous and necrotizing nocardial pneumonia with agonal septicemia was diagnosed, suggesting an aerogenous infection. To our knowledge, this is the first reported epizootic outbreak of nocardiosis in birds, which is additionally unusual because it was caused by N. nova.

Nocardia thyroiditis: unusual location of infection

Nocardia asteroides complex is an important opportunistic agent in immunocompromised hosts. Usually, primary pulmonary infection occurs and is followed by dissemination of the pathogen to the central nervous system and soft tissues. As described in the literature, almost every organ can be infected, but to our knowledge, Nocardia has been described as a pathogen responsible for thyroid abscess in only one report, which was published in 1993. The present report is the second case report of Nocardia thyroiditis. The patient was under immunosuppressor treatment following a combined liver-kidney transplant and presented with a preexisting nodular goiter which was probably a predisposing factor to the start and development of the thyroid infection.

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.

Actinomycosis and other bronchopulmonary infections with bacterial granules

Pulmonary infections with formation of bacterial granules are rare. We reviewed the clinical and pathologic data from 18 cases diagnosed using surgical specimens in our department during the last 10 years. Three clinicopathologic forms were observed: endobronchial infections complicating tuberculous sequelae or bronchiectases (n = 7), tumor-like lesions (n = 8), and diffuse pneumonia (n = 3). The two latter forms contrasted with the former by a male predominance, association with general debilitating conditions and inflammatory syndrome, and pathologically by smaller granules often located in parenchymal abscesses or excavations. The pathologic examination of the bacteria forming the granules permitted the diagnoses of actinomycosis (n = 10), botryomycosis (n = 7), or nocardiosis (n = 1). The latter case corresponded to an endobronchial infection. Both actinomycosis and botryomycosis were encountered in every clinicopathologic form. At present, pulmonary actinomycosis and related infections rarely seems to present with chest wall invasion. On the contrary, purely endobronchial forms represented a large proportion of our cases. Cultures are often difficult and the clinical appearance is not specific. However, pathologic examination with special stains must indicate the type of involved microorganism.

Disseminated nocardiosis in a bone marrow transplant recipient with chronic GVHD

We describe a case of disseminated nocardiosis in a 53-year-old male allogeneic marrow recipient with chronic GVHD, 15 years post BMT. Six months prior to admission he was treated for recurrent chronic GVHD with corticosteroids with a good response. He deteriorated subsequently while still on steroids requiring admission for fever, anorexia, weight loss, productive cough and progressive dyspnoea. On admission he had multiple nodular lesions on chest roentgenogram and subsequently grew Nocardia farcinica in blood culture. N. farcinica is rare post BMT, has a high mortality, is resistant to various antibiotics and needs prolonged antimicrobial therapy. We report the successful management of our patient with single agent trimethoprim-sulphamethoxazole.

Diversity of bacterial strains degrading hexadecane in relation to the mode of substrate uptake

The relative distribution of the modes of hydrocarbon uptake, used by bacteria of the environment for the degradation of long-chain alkanes, has been evaluated. The first mode of uptake, direct interfacial accession, involves contact of cells with hydrocarbon droplets. In the second mode, biosurfactant-mediated transfer, cell contact takes place with hydrocarbons emulsified or solubilized by biosurfactants. Sixty-one strains growing on hexadecane were isolated from polluted and non-polluted soils and identified. The majority (61%) belonged to the Corynebacterium-Mycobacterium-Nocardia group. Criteria selected for characterizing hexadecane uptake were cell hydrophobicity, interfacial and surface tensions and production of glycolipidic extracellular biosurfactants. These properties were determined in flask cultures on an insoluble (hexadecane) and on a soluble (glycerol or succinate) carbon source for a subset of 23 representative strains. Exclusive direct interfacial uptake was utilized by 47% of studied strains. A large proportion of strains (53%) produced biosurfactants. The data on cellular hydrophobicity suggested the existence of two distinct alkane transfer mechanisms in this group. Accordingly, tentative assignments of biosurfactant-mediated micellar transfer were made for 11% of the isolated strains, and of biosurfactant-enhanced interfacial uptake for 42%.

Nocardia, nocardiosis and mycetoma

The recent emergence of invasive infections due to Nocardia spp., including nosocomial outbreak, is now evident. Newer molecular diagnostic and typing methods are developed. Although sulfonamide-based therapy is generally effective, optimal treatment may be guided by antimicrobial susceptibility testing of isolates. The improved classification of nocardiae and other related genera such as actinomadurae, using the 16S ribosomal RNA sequencing, provide a sound basis for improved diagnostic methods for the identification of members of clinically significant species. The commonest cause of eumycetoma in Sudan is Madurella mycetomatis, and Streptomyces somaliensis and Actinomadura madurae for actinomycetoma. The humoral immunity response in actinomycetoma patients and in experimental mice was measured and significant titre of anti-P24 antibody was demonstrated.

Rapid identification of clinically relevant Nocardia species to genus level by 16S rRNA gene PCR

Two regions of the gene coding for 16S rRNA in Nocardia species were selected as genus-specific primer sequences for a PCR assay. The PCR protocol was tested with 60 strains of clinically relevant Nocardia isolates and type strains. It gave positive results for all strains tested. Conversely, the PCR assay was negative for all tested species belonging to the most closely related genera, including Dietzia, Gordona, Mycobacterium, Rhodococcus, Streptomyces, and Tsukamurella. Besides, unlike the latter group of isolates, all Nocardia strains exhibited one MlnI recognition site but no SacI restriction site. This assay offers a specific and rapid alternative to chemotaxonomic methods for the identification of Nocardia spp. isolated from pathogenic samples.

Accumulation of acid-fast lipochrome bodies in glial cells of the midbrain nigral lesion in Parkinson's disease

To confirm or refute the proposed link between nocardiae and Parkinson's disease (PD), we investigated the presence of acid-fast spherical structures similar to filterable nocardiae at the midbrain nigral lesions of three patients with PD. Many clusters of acid-fast lipochrome bodies were dense around blood vessels in the two patients with Hoehn and Yahr stage II and III PD. These clusters were present in the vicinity of melanin-pigmented neurons in the three PD patients studied. Examination of adjacent hematoxylin-and-eosin-stained sections indicated that they consisted of yellow-green granules, bodies, and aggregates in ballooned glial cells. On the other hand, no clusters of acid-fast lipochrome bodies were observed at the compacta region of three control patients. Our results suggest that the immunological and genetic relationship between the acid-fast lipochrome bodies and filterable nocardiae should be investigated.

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.

[Prevalence of nocardiosis in an area of endemic tuberculosis]

This is a prospective study recruiting 120 patients successively who were admitted to the chest department in hospital for respiratory infections irrespective of their aetiology. The aim of the study was to assess the frequency of nocardiosis in respiratory pathology in the era of AIDS and in an area where tuberculosis is endemic. The HIV serology was carried out on all 120 patients. A systemic search was made for nocardiosis and Koch's bacillus in the sputum and also in the broncho-alveolar lavage liquid obtained by endoscopy. The HIV serology was positive in 74 patients (61.7%). Pulmonary nocardiosis was diagnosed in five patients (4.2%), of whom four patients were HIV positive (80%). Tuberculosis was diagnosed in 58 cases (48.3%) of whom 40 were HIV positive (70%). The association of nocardiosis and tuberculosis was present in only one patient. The radioclinical aspect of nocardiosis in our service was suggestive of tuberculosis. The prevalence of nocardiosis in our series at 4.2% is in agreement with that obtained in autopsy studies in the Ivory Coast. The similarity of the radioclinical appearance between tuberculosis and nocardiosis demands that a search is made for the latter on all HIV positive patients and in negative cases a search for Koch's bacillus and empirical antibiotic therapy ought to have a spectrum of activity that would include nocardia.

Pulmonary Nocardia otitidiscaviarum infection in a patient with chronic respiratory infection

We report a case of pulmonary Nocardia (N.) otitidiscaviarum infection in a 76-year-old man with chronic respiratory infection. The patient responded poorly to intravenous imipenem and oral minocycline, but later improved after treatment with trimethoprim-sulfamethoxazole. Pulmonary infection with N. otitidiscaviarum should be considered in the differential diagnosis of chronic respiratory infections. Further studies are needed to evaluate the correlation between species and drug susceptibility.

Rhodococcus equi and Nocardia brasiliensis infection of the brain and liver in a patient with acute nonlymphoblastic leukemia

Resolution of neutropenia is usually followed by resolution of fever in patients with febrile neutropenia. However, in some cases fever continues even when the patient is no longer neutropenic. Described here is a case of acute myeloblastic leukemia complicated by brain abscess, pulmonary nodules, and hepatic lesions. The patient's fever had continued after the neutropenia resolved; brain and hepatic cultures grew Rhodococcus equi and Nocardia brasiliensis. Although Rhodococcus infections occur frequently in patients with HIV infection, they are uncommon in patients with acute leukemia.

Oerskovia xanthineolytica: a new pathogen in bone marrow transplantation

A 53-year-old woman with non-Hodgkin lymphoma underwent an autologous bone marrow transplant (BMT). Incomplete reconstitution necessitated the use of a long-term central venous catheter. One year after BMT she presented with fever. Echocardiography revealed vegetations on the tricuspid valve. Gram-positive rods grown from blood cultures and catheter tip were identified as Oerskovia xanthineolytica. We report the first case of native valve endocarditis caused by this organism.

Quantification of Gordona amarae strains in foaming activated sludge and anaerobic digester systems with oligonucleotide hybridization probes

Previous studies have shown the predominance of mycolic acid-containing filamentous actinomycetes (mycolata) in foam layers in activated sludge systems. Gordona (formerly Nocardia) amarae often is considered the major representative of this group in activated sludge foam. In this study, small-subunit rRNA genes of four G. amarae strains were sequenced, and the resulting sequences were compared to the sequence of G. amarae type strain SE-6. Comparative sequence analysis showed that the five strains used represent two lines of evolutionary descent; group 1 consists of strains NM23 and ASAC1, and group 2 contains strains SE-6, SE-102, and ASF3. The following three oligonucleotide probes were designed: a species-specific probe for G. amarae, a probe specific for group 1, and a probe targeting group 2. The probes were characterized by dissociation temperature and specificity studies, and the species-specific probe was evaluated for use in fluorescent in situ hybridizations. By using the group-specific probes, it was possible to place additional G. amarae isolates in their respective groups. The probes were used along with previously designed probes in membrane hybridizations to determine the abundance of G. amarae, group 1, group 2, bacterial, mycolata, and Gordona rRNAs in samples obtained from foaming activated sludge systems in California, Illinois, and Wisconsin. The target groups were present in significantly greater concentrations in activated sludge foam than in mixed liquor and persisted in anaerobic digesters. Hybridization results indicated that the presence of certain G. amarae strains may be regional or treatment plant specific and that previously uncharacterized G. amarae strains may be present in some systems.