A French multicentric study and review of pulmonary Nocardia spp. in cystic fibrosis patients.

Some bacterial species recovered from the airways of cystic fibrosis (CF) patients are indisputably associated with lung infections, whereas the clinical relevance of others, such as Nocardia spp., remains unclear. Sixteen French CF cases of colonization/infection with Nocardia spp. were reviewed in order to evaluate the epidemiology, the clinical impact and the potential treatment of these bacteria, and results were compared to those of the literature. Five Nocardia species were identified, Nocardia cyriacigeorgica being the major species (50 % of cases). At first isolation, Nocardia was the sole pathogen recovered in six patients. Seven patients presented pulmonary exacerbation. For 12 patients, antimicrobial treatment against Nocardia was started immediately, mainly based on cotrimoxazole (6 of the 12 cases). In this study, we highlight the heterogeneity of the clinical management of Nocardia spp. in CF. Guidelines for the clinical management of Nocardia infections in CF patients are proposed.

The Nocardia cyriacigeorgica GUH-2 genome shows ongoing adaptation of an environmental Actinobacteria to a pathogen's lifestyle.

BACKGROUND: Nocardia cyriacigeorgica is recognized as one of the most prevalent etiological agents of human nocardiosis. Human exposure to these Actinobacteria stems from direct contact with contaminated environmental matrices. The full genome sequence of N. cyriacigeorgica strain GUH-2 was studied to infer major trends in its evolution, including the acquisition of novel genetic elements that could explain its ability to thrive in multiple habitats. RESULTS: N. cyriacigeorgica strain GUH-2 genome size is 6.19 Mb-long, 82.7% of its CDS have homologs in at least another actinobacterial genome, and 74.5% of these are found in N. farcinica. Among N. cyriacigeorgica specific CDS, some are likely implicated in niche specialization such as those involved in denitrification and RuBisCO production, and are found in regions of genomic plasticity (RGP). Overall, 22 RGP were identified in this genome, representing 11.4% of its content. Some of these RGP encode a recombinase and IS elements which are indicative of genomic instability. CDS playing part in virulence were identified in this genome such as those involved in mammalian cell entry or encoding a superoxide dismutase. CDS encoding non ribosomal peptide synthetases (NRPS) and polyketide synthases (PKS) were identified, with some being likely involved in the synthesis of siderophores and toxins. COG analyses showed this genome to have an organization similar to environmental Actinobacteria. CONCLUSION: N. cyriacigeorgica GUH-2 genome shows features suggesting a diversification from an ancestral saprophytic state. GUH-2 ability at acquiring foreign DNA was found significant and to have led to functional changes likely beneficial for its environmental cycle and opportunistic colonization of a human host.

Genome sequence of the human- and animal-pathogenic strain Nocardia cyriacigeorgica GUH-2.

The pathogenic strain Nocardia cyriacigeorgica GUH-2 was isolated from a fatal human nocardiosis case, and its genome was sequenced. The complete genomic sequence of this strain contains 6,194,645 bp, an average G+C content of 68.37%, and no plasmids. We also identified several protein-coding genes to which N. cyriacigeorgica's virulence can potentially be attributed.

Imipenem-resistant Nocardia cyriacigeorgica infection in a child with chronic granulomatous disease.

Nocardia spp. can lead to local or disseminated infections, especially in immunocompromised patients. Combination therapy of amikacin and imipenem is commonly used to treat severe nocardial infections. We describe a patient with imipenem-resistant Nocardia cyriacigeorgica, which, to our knowledge, has not been previously reported among isolates of this species.

Diversity of bacteria and fungi in aerosols during screening in a green waste composting plant.

This article outlines a comprehensive analysis of the microbial diversity of aerosols produced during screening in a green waste composting plant using both culture and molecular techniques. Bacteria, thermophilic actinomycetes and fungi were quantified in the aerosols. The structure of the microbial community was examined using a fingerprint technique and DNA libraries. The results show: (i) the very high diversity of bacteria and fungi in aerosols produced during the composting screening stage, (ii) the low percentage of cultivability for bacteria in aerosols, (iii) the abundance of Thermoactinomyces spp. and Aspergillus spp. in compost aerosols.

Molecular diagnosis of culture-negative cerebral nocardiosis due to Nocardia abscessus.

We describe a case of culture-negative cerebral nocardiosis in a 34-year-old immunocompetent man who presented multiple cerebral abscesses. All bacteriologic cultures were negative. Nocardiosis was diagnosed by using a direct genus-specific 16S rDNA amplification method, and Nocardia abscessus was identified by hsp65 sequence analysis. The patient is alive and well on imipenem and doxycycline therapy, 14 months after onset.

[Brain abscess due to Nocardia cyriacigeorgica simulating an ischemic stroke]. / Un abcès cérébral à Nocardia cyriacigeorgica évocateur d'un accident vasculaire cérébral.

Nocardia spp. are bacteria often implicated in pulmonary diseases and central nervous system infections, especially in immunocompromised patients. We report here the case of an immunocompromised woman presenting an insidious brain abcess initially treated as a cerebral stroke. Despite a cotrimoxazole and rifampicin treatment she did not improve. She died 3 month later after she stopped her treatment.

Hoyosella altamirensis gen. nov., sp. nov., a new member of the order Actinomycetales isolated from a cave biofilm.

A novel actinomycete, strain OFN S31(T), was isolated from a complex biofilm in the Altamira Cave, Spain. A polyphasic study was carried out to clarify the taxonomic position of this strain. Phylogenetic analysis with 16S rRNA gene sequences of representatives of the genera Corynebacterium, Dietzia, Gordonia, Millisia, Mycobacterium, Nocardia, Rhodococcus, Segniliparus, Skermania, Tsukamurella and Williamsia indicated that strain OFN S31(T) formed a distinct taxon in the 16S rRNA gene tree that was more closely associated with the Mycobacterium clade. The type strain of Mycobacterium fallax was the closest relative of strain OFN S31(T) (95.6 % similarity). The cell wall contained meso-diaminopimelic acid, arabinose and galactose, which are characteristic components of cell-wall chemotype IV of actinomycetes. The sugars of the peptidoglycan were acetylated. The polar lipid pattern was composed of phosphatidylinositol, phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. Strain OFN S31(T) is characterized by the absence of mycelium and mycolic acids. Strain OFN S31(T) had MK-8 as the major menaquinone. The DNA G+C content was 49.3 mol%, the lowest found among all taxa included in the suborder Corynebacterineae. Based on morphological, chemotaxonomic, phenotypic and genetic characteristics, strain OFN S31(T) is considered to represent a novel species of a new genus, for which the name Hoyosella altamirensis gen. nov., sp. nov. is proposed. The type strain of Hoyosella altamirensis is strain OFN S31(T) (=CIP 109864(T) =DSM 45258(T)).

Nocardia altamirensis sp. nov., isolated from Altamira cave, Cantabria, Spain.

A novel actinomycete strain, OFN S17(T), was isolated from a sample collected from Altamira Cave, Cantabria, Spain. This strain was identified by using a polyphasic taxonomic approach. The 16S rRNA, hsp65 and sod gene sequences of the strain were determined and compared with those of representative Nocardia species. The results showed that strain OFN S17(T) should be assigned to the genus Nocardia. Phylogenetic analysis indicated that strain OFN S17(T) was most closely related to the type strain of Nocardia tenerifensis (98.6, 96.2 and 96% similarity, respectively, for the 16S rRNA, hsp65 and sod gene sequences). The DNA G+C content was 64.4 mol%. DNA-DNA hybridization analyses revealed 29% relative reassociation between the DNA of strain OFN S17(T) and N. tenerifensis DSM 44704(T). The phenotypic and genotypic data show that strain OFN S17(T) merits recognition as a representative of a novel species of the genus Nocardia, for which the name Nocardia altamirensis sp. nov. is proposed. The type strain is OFN S17(T) (=CIP 109606(T) =DSM 44997(T)).

Nocardia brasiliensis in Italy: a nine-year experience.

In the past, no case reports concerning N. brasiliensis infections were published from Italy. We now report 4 cases observed during 1998-2006 in 4 Italian patients, 1 immunosuppressed and 3 immunocompetent.

Nocardia coubleae sp. nov., isolated from oil-contaminated Kuwaiti soil.

Two bacterial isolates from Kuwaiti soil contaminated by crude oil were analysed by using a polyphasic taxonomic approach. The isolates, designated OFN N11 and OFN N12(T), were shown to have molecular, chemical and morphological properties typical of members of the genus Nocardia. Based on a multigenic approach that included 16S rRNA, hsp65 and sod gene sequencing, these novel isolates formed a monophyletic clade within the genus Nocardia. The closest species was Nocardia ignorata (with 99.4 %, 99.5 %, 98.6 % gene sequence similarity to the 16S rRNA, hsp65 and sod genes, respectively). The novel isolates could be distinguished phenotypically from the type strains of recognized species of the genus Nocardia. The novel isolates were not related to the type strain of N. ignorata in DNA-DNA hybridization experiments (26 % relatedness). On the basis of these genotypic and phenotypic data, the two isolates appear to represent a novel species, for which the name Nocardia coubleae sp. nov. is proposed. The type strain is OFN N12(T) (=DSM 44960(T)=CIP 108996(T)).

Nocardia ninae sp. nov., isolated from a bronchial aspirate.

A Gram-positive and acid-fast filamentous bacterium (OFN 02.72(T)) was isolated from a bronchial aspirate from a 53-year-old patient. Chemotaxonomic data supported the affiliation of this organism to the genus Nocardia, and the phenotypic characteristics demonstrated that the strain differed from all previously described Nocardia species. Restriction enzyme analysis of the hsp65 gene (encoding the 65 kDa heat-shock protein) and sequencing of the 16S rRNA and hsp65 genes confirmed that this isolate is unique. The most closely related type strains were Nocardia alba YIM 30243(T) (=DSM 44684(T)) and Nocardia jejuensis N3-2(T) (=JCM 13281(T)) (with 16S rRNA gene sequence similarities of 98.3 and 97.2 %, respectively). On the basis of this polyphasic study, strain OFN 02.72(T) represents a novel species within the genus Nocardia, for which the name Nocardia ninae sp. nov. is proposed. The type strain is OFN 02.72(T) (=CIP 108955(T)=DSM 44978(T)).

Nocardia nova as the causative agent in spondylodiscitis and psoas abscess.

We describe here the first case of Nocardia nova spondylodiscitis accompanied by a psoas abscess due to spreading from pulmonary nocardiosis. Nocardia was cultured from all affected sites. After 1 year of an appropriate antimicrobial therapy and a surgical drainage of the abscess that was required, the patient's clinical condition had improved.

Use of PCR-restriction enzyme pattern analysis and sequencing database for hsp65 gene-based identification of Nocardia species.

Nocardia identification required laborious and time-consuming phenotypic and chemotaxonomic methods until molecular methods were developed in the mid-1990s. Here we reassessed the capacity of PCR-restriction enzyme pattern analysis (PRA) of the hsp65 gene to differentiate Nocardia species, including 36 new species. Our results confirm that hsp65 PRA must no longer be used for Nocardia species identification, as many species have the same restriction pattern. We then compared sequencing-based strategies using an hsp65 database and a 16S rRNA database and found that the hsp65 region contained sufficient polymorphisms for comprehensive Nocardia species identification.

Antifungal effects of aminosulphoxide and disulphide derivatives.

2-Benzenesulphinyl-(1,4)-naphtoquinone and 14 derivatives were synthesised and were used to evaluate their cytotoxicity against a human myelomonocyte cell line and their antifungal activity against two yeast, i.e. Candida albicans and C. tropicalis and against two filamentous fungi such as Aspergillus niger and Fusarium oxysporum and against one dermatophyte, namely Trichophyton tonsurans. The cytotoxicity and antifungal activities were investigated in comparison with amphotericin B as reference drug. No compound was significantly more toxic than amphotericin B at 0.2 microg ml(-1). The best results of antifungal activity were obtained with GFL 10, GFL 13 and GFL 30 on C. tropicalis, F. oxysporum and T. tonsurans. For C. albicans and A. niger, there was no difference between amphotericin B and the other molecules. The sterol quantitation, the time-kill curves were carried out for these three compounds in order to confirm their action in ergosterol synthesis. Time-kill curves showed a fungistatic activity. For C. tropicalis GFL 10, GFL 13 and GFL 30 increased the growth delay better than amphotericin B, in contrast to F. oxysporum. As for T. tonsurans, GFL10 and GFL13 gave a delay, but the effect of GFL 30 was a bit less marked.

Disseminated nocardiosis due to unusual species: two case reports.

Pulmonary nocardiosis is the major clinical manifestation of human nocardiosis and disseminated infection can be seen in immunocompromised patients. N. asteroides is the predominant pathogen associated with disseminated diseases. We report 2 cases of pulmonary nocardiosis admitted with disseminated infection, caused by rare species of Nocardia: Nocardia transvalensis and Nocardia cyriacigeorgica.

Direct detection of Nocardia spp. in clinical samples by a rapid molecular method.

We developed a 16S PCR-based assay for the rapid detection of Nocardia spp. directly from human clinical samples. The applicability of the assay was confirmed by using 18 samples from patients with nocardiosis as diagnosed by conventional cultures and 20 clinical samples from patients with confirmed tuberculosis used as negative controls.

Nocardia ignorata, a new agent of human nocardiosis isolated from respiratory specimens in Europe and soil samples from Kuwait.

Nocardia ignorata is a recently described species identified on the basis of a single isolate of unknown origin. Here we describe the epidemiological, phenotypic, and phylogenetic characteristics of this new species, based on five new clinical and soil isolates.

Nocardia mexicana sp. nov., a new pathogen isolated from human mycetomas.

Three isolates collected from human mycetomas and showing an unusual brownish purple pigmentation on Bennett agar plates were analyzed by a polyphasic taxonomic approach, including morphological, biochemical, physiological, and chemotaxonomic properties coupled with genomic and phylogenetic analysis. It clearly appeared that these microorganisms were distinct from their closest phenotypic and genetic match, the most related species according to 16S rRNA gene sequence analysis being Nocardia pseudobrasiliensis. The data obtained indicated that the three clinical strains should be recognized as a new species for which the name Nocardia mexicana sp. nov. is proposed.

Nocardia veterana isolated from ascitic fluid of a patient with human immunodeficiency virus infection.

Nocardia veterana is a recently characterized species within the genus Nocardia, and only three human clinical isolates have been reported for this species. We describe a case of ascitic fluid infection in an immunocompromised patient due to N. veterana. To our knowledge, this is the first report of a Nocardia sp. strain from ascitic fluid and the fourth report of N. veterana isolated from human samples. Chemotaxonomic methods showed the strain to belong to the genus Nocardia, and identification to the species level was done by 16S ribosomal DNA gene sequencing. The antibiotic susceptibility profile of N. veterana is reported here for the second time. The strain was deposited in the Collection of the Pasteur Institute and in the Culture Collection of the University of Göteborg (CIP 107497 and CCUG 46576). The corresponding 16S ribosomal DNA gene sequence is available from the GenBank database under accession number AY149599. A phylogenetic analysis was conducted and showed that N. veterana was most closely related to the recently characterized species Nocardia africana rather than to Nocardia vaccinii, as previously reported.