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A Japanese male in his 30s with no underlying medical condition presented with painless nodules after being bitten by a dog during a stay in Bali, Indonesia, 7 years earlier. He was referred to our department with multiple ulcers, nodules, and masses on the right leg. The final diagnosis was mycetoma caused by Nocardia vulneris, which may have been exacerbated by colonization of Candida parapsilosis and C. tropicalis as these yeasts were isolated by culture from the tissue. Treatment with minocycline hydrochloride and sulfamethoxazole trimethoprim showed partial efficacy, but the addition of posaconazole achieved significant efficacy. This suggests that the surmised coexistence of pathogenic yeasts of lower virulency may have made mycetoma in this case intractable., (© 2024 Japanese Dermatological Association.)

Two novel actinobacteria, designated IFM 12276 T and IFM 12275, were isolated from clinical specimens in Japan, and their taxonomic positions were investigated using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strains IFM 12276 T and IFM 12275 have completely identical 16S rRNA gene sequences and were closely related to members of the genus Nocardia . The highest 16S rRNA gene sequence similarity was observed to Nocardia beijingensis (99.6 %) and Nocarida sputi (99.6 %), followed by Nocardia niwae (99.3 %) and Nocardia araoensis (99.3 %). The whole-cell hydrolysates of strains IFM 12276 T and IFM 12275 contained meso -diaminopimelic acid, arabinose and galactose. The acyl type of muramic acid was N -glycolyl. The predominant isoprenoid quinone was MK-8(H 4 , ω -cycl.) and the principal polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. Strains IFM 12276 T and IFM 12275 contained mycolic acids that co-migrated with those from the type strain of N. niwae . These chemotaxonomic features corresponded to those of the genus Nocardia . Meanwhile, the differences in some phenotypic characteristics, along with the results of average nucleotide identity and digital DNA-DNA hybridization analyses, indicated that strains IFM 12276 T and IFM 12275 should be distinguished from the recognized species of the genus Nocardia . Therefore, these strains represent a novel species of the genus Nocardia , for which the name Nocardia sputorum sp. nov. is proposed. The type strain is IFM 12276 T (=NBRC 115477 T =TBRC 17096 T ).

Patients after lung transplantation are at risk for Nocardia infections. We herein report a case of lung and cerebral nocardiosis caused by Nocardia elegans, a rare species of Nocardia, in a lung transplant recipient. Antibiotic therapy, including sulfamethoxazole-trimethoprim (ST), and brain abscess drainage improved symptoms and imaging findings. A literature review of N. elegans infections showed that 12 of 14 cases (85.7%) were reported from East Asia, particularly Japan (9 cases, 64.2%). The lungs were the predominant site (12/14 cases, 85.7%), and most of the cases were susceptible to ST (9/10 cases, 90%).

Two new peptides named uniformides A and B ( 1 and 2 , respectively) were isolated from the cultured extracts of Nocardia uniformis IFM0856 T in the presence of mouse macrophage-like cell line J774.1, in modified Czapek-Dox medium. These compounds were not produced in a culture containing only N. uniformis but in one that also included J774.1. Compounds 1 and 2 showed high cytotoxicity against J774.1 and suppressed the production of nitric oxide, IL-6, and IL-1β by inhibiting the NF-κB pathway.

A 69-year-old woman who had undergone renal transplantation and was receiving sulfamethoxazole/trimethoprim (ST) developed pulmonary nocardiosis. To our knowledge, this is the first report of the identification of Nocardia elegans using nanopore sequencing, supported by 16S rDNA capillary sequencing findings. Chest computed tomography performed after ST initiation revealed significant improvement of the pulmonary shadows compared to previous findings. We herein report the value of nanopore sequencing for rapid identification of rare pathogens, such as Nocardia elegans. Furthermore, our findings suggest that Nocardia may infect even patients receiving ST, which is currently the most effective prophylactic drug.

Nocardia species cause a broad spectrum of infections, especially in immunocompromised patients. Given its relative rarity, data on the prognosis and distribution of nocardiosis from a large cohort are scarce. The present study aimed to scrutinize the clinical features and outcomes of nocardiosis in Japan, including 1-year mortality and microbiological data. The present multicentric, retrospective cohort study enrolled patients aged ≥18 years with nocardiosis diagnosed between January 2010 and December 2017 and recorded their clinical and microbiological characteristics. Factors associated with 1-year mortality were also determined using Cox proportional hazard analysis. In total, 317 patients were identified at 89 hospitals. Almost half (155/317, 48.9%) were receiving immunosuppressive agents, and 51 had disseminated nocardiosis (51/317, 16.1%). The 1-year all-cause mortality rate was 29.4% (80/272; lost to follow-up, n  = 45). The most frequently isolated species was Nocardia farcinica (79/317, 24.9%) followed by the Nocardia nova complex (61/317, 19.2%). Selected antimicrobial agents were generally effective, with linezolid (100% susceptibility [S]) and amikacin (94% S) having the most activity against Nocardia species. In Cox proportional hazard analysis, factors independently associated with 1-year mortality were a Charlson comorbidity index score of ≥5 (adjusted hazard ratio [aHR], 3.61; 95% confidence interval [CI], 1.95 to 6.71, P <  0.001) and disseminated nocardiosis (aHR, 1.79; 95%CI, 1.01 to 3.18, P =  0.047). The presence of advanced comorbidities and disseminated infection, rather than variations in antimicrobial therapy or Nocardia species, was independently associated with 1-year mortality.

Notch signaling inhibitors with the potential of immune suppressor production by pathogenic bacteria for easy host infection were searched from extracts of Nocardia sp. Nocobactin NA-a (compound 1) and nocobactin NA-b (compound 2), which have been suggested as pathogenesis factors, were isolated from N. farcinica IFM 11523 isolated from the sputum of a Japanese patient with chronic bronchitis. Compounds 1 and 2 showed Notch inhibitory activities with IC 50 values of 12.4 and 17.6 μM, respectively. Compound 1 and 2 decreased of Notch1 protein, Notch intracellular domain, and hairy and enhancer of split 1, which is a Notch signaling target protein. In addition, compounds 1 and 2 showed cytotoxicity against mouse macrophage-like cell line RAW264.7 with IC 50 values of 18.9 and 21.1 μM, respectively. These results suggested that the Notch inhibitors production by pathogenic bacteria may increase pathogen infectivity.

Objective: The purpose of this study was to describe the clinical features of nocardiosis after allogeneic hematopoietic stem cell transplantation (allo-HSCT), focusing on new Nocardia species., Methods: We retrospectively reviewed data from patients with nocardiosis after allo-HSCT treated at our hospital and documented cases in the medical literature., Results: Fifty-seven cases were identified from our institution and the literature review. Although 51 patients (89.5%) responded to initial treatment, 28 (49.1%) patients were switched over to other treatment regimens due to the recurrence of nocardiosis or adverse events of antimicrobials. Nocardiosis-attributed mortality occurred in ten patients (17.5%). Antimicrobial susceptibilities varied among intra- and inter-species except linezolid (LZD). In the present study, five species were newly discovered after 2000, including N. cyriacigeorgica, N. veterana, N. abscessus, N. aobensis, and N. mexicana. All isolates of N. cyriacigeorgica, N. veterana, N. abscessus, and N. aobensis were sensitive to trimethoprim/sulfamethoxazole, amikacin (AMK), imipenem (IPM), and LZD; however, N. mexicana was resistant to AMK and IPM., Conclusion: Newly identified Nocardia species have various antimicrobial susceptibility patterns. Long-term maintenance therapy could be challenging due to the adverse events of antimicrobials, especially in the allo-HSCT setting. Prudent evaluation is crucial for selecting a second-line or further treatment options., (Copyright © 2019 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Here, we present a case of disseminated nocardiosis, involving pneumonia, percutaneous abscess, and bacteremia, in a 67-year-old Japanese woman. She had also been treated for rheumatoid arthritis with prednisolone, methotrexate, and tocilizumab (interleukin-6 receptor inhibitor). Based on the 16S rRNA sequence analysis and a blast search, we identified the isolate as Nocardia brasiliensis. We discontinued methotrexate and tocilizumab on admission, and administered intravenous antimicrobial combination therapy for 6 weeks, followed by oral trimethoprim-sulfamethoxazole for 12 months, in total. Nocardia bacteremia is rare, often difficult to diagnose, and substantially fatal. However, due to our prompt diagnosis within one day of the onset of symptoms, and administration of appropriate treatment based on antimicrobial susceptibilities, this patient succeeded in surviving the infection. Not only microbiologists but also clinicians should be aware of the characteristic bacterial form of Gram/Kinyoun staining for early recognition of nocardiosis., (Copyright © 2019 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

A coculture method with a pathogenic actinomycete of the genus Nocardia and an animal cell line was designed to reconstruct and emulate the initial infection state, and a new cyclic nonapeptide, named nocarjamide (1), was obtained by coculture of Nocardia tenerifensis IFM 10554 T and the mouse macrophage-like cell line J774.1 in a modified Czapek-Dox medium. Nocarjamide (1) exhibited Wnt signal-activating effects.

A new amide, named dehydropropylpantothenamide (1), was obtained by a co-culture of Nocardia tenerifensis IFM 10554 T in the presence of the mouse macrophage-like cell line J774.1 in modified Czapek-Dox (mCD) medium. Compound 1 was synthesized from D-pantothenic acid calcium salt in 6 steps. The absolute configuration of natural compound 1 was determined by comparisons of the optical rotation and CD spectra of synthetic 1. In the present study, a new method for producing secondary metabolites was demonstrated using a "co-culture" in which the genus Nocardia was cultured in the presence of an animal cell line.

A nocardioform strain IFM 11456T was isolated from the aqueous humor from a patient with endophthalmitis and was characterized to its taxonomic position. IFM 11456T contained arabinose, galactose and meso-diaminopimelic acid in whole-cell hydrolysates and mycolic acids that co-migrated with those from the type strain of Nocardiaasteroides. The acyl type of muramic acid was N-glycolyl. The diagnostic polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and two unidentified glycolipids and the predominant menaquinone was MK-8(H4, ω-cycl.). These characteristics are typical of members of the genus Nocardia. Results of phylogenetic analyses based on 16S rRNA gene sequences indicated that the isolate represented a novel species of the genus Nocardia and was most closely related to the type strains of Nocardia mikamii JCM 15508T (98.1 %) and Nocardiaaobensis IFM 0372T (98.1 %). However, analysis of partial gyrB sequences showed that strain IFM 11456T had 90.2 % similarity to Nocardia concava IFM 0354T and 90 % to Nocardianiigatensis IFM 0330T. The DNA-DNA relatedness values for strain IFM 11456T compared with N. mikamii JCM 15508T, N. aobensisIFM 0372T and N. concava IFM 0354T ranged from 24.4 to 39.9 %. Phenotypic characteristics that differentiated IFM 11456T from phylogenetically related species were growth at 45 °C, utilization of citrate and growth with inositol as a sole carbon source. On the basis of this polyphasic study, the isolate represents a novel species within the genus Nocardia, for which the name Nocardia shinanonensis sp. nov. is proposed. The type strain is IFM 11456T (=NBRC 109590T=TBRC 5149T).

We report a lymphocutaneous type of nocardiosis caused by Nocardia vinacea. A 62-year-old woman with polymyositis presented with some erythematous swellings and subcutaneous abscesses on her right middle finger and the dorsum of her hand, which had persisted for 2 weeks. Culturing of the excised nodule and pus revealed orange to orange-tan colonies with scanty whitish aerial mycelia. The isolate was identified as N. vinacea on the basis of its biochemical and chemotaxonomic characteristics and the results of molecular biological analysis. In our case, oral minocycline (MINO) and trimethoprim-sulfamethoxazole (TMP-SMX) for 7 weeks did not improve the clinical manifestation, even though in vitro susceptibility testing of the isolate predicted its susceptibility to MINO and TMP-SMX. Treatment with partial surgical excision followed by TMP-SMX and meropenem administration was effective. This is the first reported case of a lymphocutaneous type of nocardiosis caused by N. vinacea.