Occipital Nocardia Abscess Presenting With Positive Visual Phenomenon and Quadrantanopsia.

ABSTRACT: A 74-year-old man with chronic obstructive pulmonary disease, glaucoma, and Stage IIIB squamous cell lung cancer experienced several minutes of flashing lights in his right visual hemifield, followed by onset of a right visual field defect. On examination, the patient had a right homonymous hemianopsia that was most dense inferiorly by confrontation testing. Emergent CT scan of the head revealed a 2.5 × 3 cm hypodensity in the left occipital lobe, which was interpreted as an acute stroke. Continuous EEG monitoring captured left posterior quadrant seizures that were temporally correlated to the positive visual phenomena. Subsequent MRI of the brain with and without contrast revealed a conglomerate of centrally necrotic and peripherally enhancing mass lesions. On biopsy, a thick purulent material was drained and Gram stain of the sample revealed gram-positive beaded rods, which speciated to Nocardia farcinica . The patient was treated with a six-week course of intravenous meropenem and a one-year course of oral trimethroprim-sulfamethoxazole. On follow-up, the patient experienced resolution of the right visual field deficit.

Nocardia spp. isolation in chronic lung diseases: Are there differences between patients with pulmonary nocardiosis and Nocardia colonization?

AIMS: Chronic lung diseases are a recognized risk factor for Nocardia spp. INFECTION: Nocardia spp. isolation does not inevitably imply disease, and thus colonization must be considered. Here, we aimed to analyse the differences between pulmonary nocardiosis (PN) and Nocardia spp. colonization in patients with chronic lung diseases. METHODS AND RESULTS: A retrospective study of patients with laboratory confirmation of isolation of Nocardia spp. in at least one respiratory sample was performed. Patients with PN and Nocardia spp. colonization were compared. There were 71 patients with Nocardia spp. identification, 64.8% were male, with a mean age of 67.7 ± 11.2 years. All patients had ≥1 pre-existing chronic lung disease, and 19.7% of patients were immunocompromised. PN and Nocardia spp. colonization were considered in 26.8% and 73.2% of patients, respectively. Symptoms and chest CT findings were significantly more frequent in patients with PN (p < 0.001). During follow-up time, 12 (16.9%) patients died, 6 in PN group. Immunosuppression, constitutional symptoms, haematological malignancy and PN diagnosis were associated with significantly shorter survival times, despite only immunosuppression (HR 3.399; 95% CI 1.052-10.989) and PN diagnosis (HR 3.568; 95% CI 1.078-11.910) remained associated with a higher death risk in multivariate analysis. CONCLUSIONS: PN was associated with clinical worsening, more chest CT findings and worse clinical outcomes. SIGNIFICANCE AND IMPACT OF STUDY: Nocardia spp. isolation in chronic lung disease patients is more common than expected and the differentiation between colonization and disease is crucial.

Nocardia beijingensis lung mass in an immunocompetent adult.

A 47-year-old man was referred for ongoing workup of an enlarging lung mass. Extensive workup of the mass had been unrevealing for several months until cultures grew Nocardia beijingensis He was successfully treated with trimethoprim/sulfamethoxazole and then doxycycline with near-complete resolution of the mass on follow-up. This case presents a rare species of N. beijingensis It highlights the importance of considering nocardiosis in immunocompetent adults and the challenge in initiating targeted treatment due to delayed culture results.

A rare disease mimicking lung cancer.

We present an interesting case of a 34 year old gentleman with bilateral FDG avid lesions in the apex of the lung. He presented with a two month history of cough, fever and hemoptysis. A contrast enhanced CT scan showed a spiculated lesion in the right upper lobe. A CT guided biopsy was done which was suggestive of an inflammatory lesion. He was started empirically on anti tubercular therapy, but his symptoms did not subside. A PET CT scan was done, which showed the lesion to be FDG avid. A repeat biopsy was done and again it was reported as an inflammatory infiltrate. He was then referred to our center for a surgical biopsy. We repeated a PET scan and were surprised to find another lesion in the apex of the opposite lung. The case was discussed with our interventional pulmonogy team and an EBUS guided biopsy of the lesion was done. On microbiological analysis the specimen was found to be positive for Nocardia.

A case report of disseminated nocardiosis with ocular involvement in a myasthenia gravis patient and literature review.

BACKGROUND: Nocardiosis is a rare and life-threatening opportunistic infection in immunocompromised patients. Myasthenia gravis (MG) patients are potentially at risk of nocardia infection because of the use of immunosuppressive agents. To date, only 7 patients with MG have been reported to have nocardiosis. Disseminated nocardiosis with ocular involvement has not been reported in MG patients. CASE PRESENTATION: A 66-year-old man with MG who was receiving treatment with methylprednisolone and azathioprine was found to have a respiratory infection. He also had heterogeneous symptoms with skin, brain and ocular manifestations. Nocardia bacteria verified by the culture of puncture fluid, and a diagnosis of disseminated nocardiosis was made. Except for left eye blindness, the patient completely recovered from the disease with combination antibiotic therapy. To further understand nocardiosis in patients with MG, we reviewed the previous relevant literature. According to the literature, this is the first report of disseminated nocardiosis with ocular involvement in an MG patient. CONCLUSIONS: MG patients with immunosuppressant treatments are potentially at risk of a rare nocardia infection, and a favourable prognosis can be achieved through early diagnosis and appropriate antibiotic therapy.

Nocardial endocarditis in native aortic valve with nocardial sepsis in a case of breast cancer.

Central venous catheter-associated bacteraemia caused by Nocardia species is very rare; the diagnosis of nocardiosis in patients with cancer is challenging because its clinical presentation is varied, sometimes mimicking metastases, and the high index of clinical suspicion is required for prompt institution of therapy. Herein, we report a case of nocardial sepsis with native aortic valve endocarditis in a patient with breast cancer in whom multidisciplinary team involvement and prompt initiation of therapy have led to successful outcome.

First case report of fatal Nocardia nova infection in yellow-bibbed lory (Lorius chlorocercus) identified by multilocus sequencing.

BACKGROUND: Nocardiosis is often a multi-systemic disease in humans and other mammals. Nocardiosis in birds is uncommon. Laboratory identification of Nocardia to the species level is difficult by traditional phenotypic methods based on biochemical reactions and hydrolysis tests, and is most accurately performed by sequencing multiple gene targets. CASE PRESENTATION: We report the first case of fatal Nocardia nova infection in a yellow-bibbed lory nestling in an oceanarium diagnosed by multilocus sequencing. Necropsy examination showed effacement of normal sternal musculature with yellowish, firm aberrant material, and diffuse infiltration of the lungs with nodular, tan to yellow foci. Histologically, severe granulomatous inflammation with marked necrosis was observed in the lung, spleen and sternal musculature. Fine, sometimes Gram-positive, 0.5-1 µm wide, branching and beaded filamentous organisms were visible within the lesions. They were acid-fast on Fite-Faraco stain. Tissue samples obtained from the sternum, liver, right lung and right kidney recovered Nocardia species. Sequencing of four gene loci and phylogenetic analysis of concatenated (gyrB-16S-secA1-hsp65) sequences revealed that the isolate was N. nova. CONCLUSIONS: We report the first case of N. nova infection in yellow-bibbed lorry (Lorius chlorocercus). The present case is the first one of which the species identity of the isolate was determined by multilocus sequencing. Molecular diagnosis is important for identifying the Nocardia to species level and understanding the epidemiology of nocardiosis in birds.

Disseminated nocardiosis with cerebral and subcutaneous lesions on low-dose prednisone.

This case report is of a septuagenarian man on chronic low-dose prednisone who presented with disseminated nocardiosis (Nocardia cyriacigeorgica) that was initially mistaken for metastatic brain cancer. Neurologists should be aware of the potential for opportunistic infections with steroid use and to consider a definite tissue diagnosis with culture and histopathology prior to treatment.

Características epidemiológicas, clínico-patológicas e morfotintoriais de quatorze casos de nocardiose em cães / Epidemiological, clinical, pathological and morphotinctorial features of fourteen cases of nocardiosis in dogs

Este artigo descreve os aspectos epidemiológicos, clínicos, patológicos e características morfotintoriais em quatorze casos de nocardiose em cães. Para isso foi realizado um estudo retrospectivo durante o período de janeiro de 2005 a dezembro de 2015 e selecionados os casos sugestivos de nocardiose. A identificação e caracterização do agente foi realizada através de técnicas histoquímicas especiais de Metenamina nitrato de prata de Grocott (GMS), Ziehl-Neelsen modificado, coloração de Gram do tipo Brown-Brenn modificado e Giemsa. Foram afetados predominantemente filhotes e em doze casos havia associação com o vírus da cinomose canina (VCC). Os sinais clínicos variaram de alterações respiratórias, neurológicas e cutâneas, relacionadas principalmente à infecção concomitante pelo VCC. Macroscopicamente haviam áreas multifocais a coalescentes, branco-amareladas, firmes, elevadas na superfície e que se aprofundavam ao corte, por vezes com material purulento, entremeadas por áreas avermelhadas irregulares afetando principalmente pulmões, linfonodos, fígado, rins e encéfalo. As lesões cutâneas foram observadas predominantemente nas regiões cervical e inguinal e variaram de supurativas a piogranulomatosas. No exame histopatológico a lesão era caracterizada principalmente por inflamação piogranulomatosa, porém em algumas áreas havia predomínio de inflamação necrossupurativa, e frequentemente eram observados macrófagos epitelioides, formando aglomerados de forma radiada, muitas vezes lembrando pseudorosetas. Nas técnicas histoquímicas foram observadas estruturas filamentosas, ramificadas, não septadas, medindo aproximadamente 1µm de espessura, impregnadas na coloração de prata, coradas em vermelho no Ziehl-Neelsen modificado, em azul na coloração de Gram do tipo Brown-Brenn modificado e fracamente rósea pálido no Giemsa. A nocardiose deve ser considerada em animais jovens que apresentam sinais respiratórios e neurológicos progressivos, bem como em lesões cutâneas com envolvimento do subcutâneo e linfonodos regionais. Deve ser investigado ainda um provável fator predisponente, como a infecção pelo vírus da cinomose canina e hemoparasitoses. O diagnóstico foi estabelecido através do exame histopatológico baseando-se na morfologia da bactéria e suas características histoquímicas, distinguindo principalmente de outros agentes bacterianos e fúngicos, constituindo uma importante ferramenta para o diagnóstico, quando não é possível a coleta do material para cultivo e isolamento do agente.(AU)

This paper describes the epidemiological, clinical, pathological and morphotinctorial characteristics in fourteen cases of nocardiosis in dogs. A retrospective study for the period of January 2005 to December 2015 was made and selected suggestive cases of nocardiosis. The identification and characterization of the agent was performed by special histochemical techniques Methenamine silver nitrate Grocott (GMS), modified Ziehl-Neelsen, Gram stain type modified Brown-Brenn and Giemsa. Were affected predominantly young and in twelve cases were associated with canine distemper virus (CDV). Clinical signs vary from respiratory, neurological and skin changes, mainly related to concomitant infection by CDV. Macroscopically had multifocal areas coalescing, yellowish-white, firm, elevated in surface and deepened the court, sometimes with purulent material, intermixed by irregular reddened areas affecting mainly lungs, lymph nodes, liver, kidneys, and brain. The cutaneous lesions were predominantly observed in cervical and inguinal and ranged from suppurative well as pyogranulomatous. In the histopathologic examination the injury was mainly characterized by inflammation pyogranulomatous, but in some areas there was a predominance of necrossupurativa inflammation, epithelioid macrophages and were frequently observed, forming clusters radiated form, often reminding rosettes. In the histochemical techniques were observed filamentous structures, branched, non-septate, measuring approximately 1µm thick, impregnated on silver staining, stained in red on the modified Ziehl-Neelsen, in blue on Gram stain type modified Brown-Brenn and weakly pale pink in Giemsa. The nocardiosis should be considered in young animals with progressive respiratory and neurological signs, as well as skin lesions involving the subcutaneous tissue and regional lymph nodes. It should be further investigated a possible predisposing factor, such as infection by canine distemper virus and hemoparasites. The diagnosis was established by histopathological examination based on the morphology of the bacteria and their histochemical characteristics, distinguishing mainly from other bacterial and fungal agents and is an important tool for the diagnosis, when the collection of material for cultivation and isolation of the agent is not possible.(AU)

Transparent Tiger barb Puntius tetrazona, a fish model for in vivo analysis of nocardial infection.

Nocardiosis afflicts multiple species of cultured fish, resulting in substantial economic losses to the aquaculture industry, however, lack of detailed knowledge on disease pathogenesis has hampered the development of effective prevention and control strategies. In this study, we injected a green fluorescent protein (GFP)-labeled Nocardia seriolae strain into a transparent mutant strain of Tiger barb (Puntius tetrazona) to monitor tissue pathogen accumulation and tissue damage in vivo, and to clarify the relationship between pathogenic processes and overt symptoms. GFP-labeled bacteria were phagocytized by leukocytes and could proliferate within these cells, which in turn led to leukocyte aggregation, leukocyte death, and granuloma formation. In addition, intracellular bacteria could permanently colonize various tissues via leukocyte circulation, causing multi-organ infection as revealed by changes of tissue transparency. Histology revealed granulomatous lesions in organs such as muscle, kidney, and spleen that was corresponded to the tissue opacities in vivo. Confocal microscopy confirmed massive accumulations of GFP-labeled bacteria within these granulomas, which often contained a necrotic core. Tiger barb transparency allows for real-time observation of in vivo pathological changes within the same animal, and the pathogenic process can be evaluated based on the shape and size of body opacities. Thus, transparent Tiger barb is a promising model to study the pathogenesis of nocardiosis.

Nocardiosis in freshwater reared Chinook salmon (Oncorhynchus tshawytscha).

CASE HISTORY: An investigation was conducted to identify the cause of mortalities in freshwater reared Chinook salmon (Oncorhynchus tshawytscha). Mortalities occurred in juvenile salmon, at a salmon rearing facility in the South Island of New Zealand. The affected fish were from a pen inside the facility with no surrounding pens or other year classes affected. CLINICAL FINDINGS: Clinically affected fish presented with skin lesions. The majority of skin lesions were unruptured, boil-like, raised circular masses up to 4 cm in diameter, particularly on the dorsolateral aspects and the flank. A number of fish presented with large ulcers resulting from rupturing of the raised lesions described above. This clinical presentation showed similarities to that of furunculosis caused by typical Aeromonas salmonicida, a bacterium exotic to New Zealand. LABORATORY FINDINGS: Samples were taken from two representative fish in the field for histopathology, bacterial culture and molecular testing. Histopathological findings included granulomatous lesions in the kidney, liver, spleen and muscle. When stained with Fite-Faraco modified acid fast stain filamentous branching rods were identified within these granulomas. Following bacterial culture of kidney swabs pure growth of small white matt adherent colonies was observed. This isolate was identified as a Nocardia species by biochemical testing and nucleotide sequencing of the partial 16S rRNA gene. All samples were negative for A. salmonicida based on bacterial culture and PCR testing. DIAGNOSIS: Nocardiosis caused by a Nocardia species. CLINICAL RELEVANCE: Nocardiosis in these fish was caused by a previously undescribed Nocardia species that differs from the species known to be pathogenic to fish: N. asteroides, N. salmonicida and N. seriole. This bacterium is likely to be a new or unnamed environmental species of Nocardia that has the potential to cause disease in Chinook salmon under certain conditions. The clinical presentation of this Nocardia species manifested as raised, boil-like skin lesions which has similarities to the presentation of furunculosis caused by the bacterium typical A. salmonicida, a species exotic to New Zealand.

Experimental Granulomatous Pulmonary Nocardiosis in BALB/C Mice.

Pulmonary nocardiosis is a granulomatous disease with high mortality that affects both immunosuppressed and immunocompetent patients. The mechanisms leading to the establishment and progression of the infection are currently unknown. An animal model to study these mechanisms is sorely needed. We report the first in vivo model of granulomatous pulmonary nocardiosis that closely resembles human pathology. BALB/c mice infected intranasally with two different doses of GFP-expressing Nocardia brasiliensis ATCC700358 (NbGFP), develop weight loss and pulmonary granulomas. Mice infected with 109 CFUs progressed towards death within a week while mice infected with 108 CFUs died after five to six months. Histological examination of the lungs revealed that both the higher and lower doses of NbGFP induced granulomas with NbGFP clearly identifiable at the center of the lesions. Mice exposed to 108 CFUs and subsequently to 109 CFUs were not protected against disease severity but had less granulomas suggesting some degree of protection. Attempts to identify a cellular target for the infection were unsuccessful but we found that bacterial microcolonies in the suspension used to infect mice were responsible for the establishment of the disease. Small microcolonies of NbGFP, incompatible with nocardial doubling times starting from unicellular organisms, were identified in the lung as early as six hours after infection. Mice infected with highly purified unicellular preparations of NbGFP did not develop granulomas despite showing weight loss. Finally, intranasal delivery of nocardial microcolonies was enough for mice to develop granulomas with minimal weight loss. Taken together these results show that Nocardia brasiliensis microcolonies are both necessary and sufficient for the development of granulomatous pulmonary nocardiosis in mice.

Resolution of innumerable cerebral Nocardia paucivorans abscesses after medical management.

Nocardia species are an infrequent cause of brain abscesses. We report a 50-year-old man with Nocardia paucivorans cerebral abscesses. Brain MRI revealed innumerable small ring-enhancing lesions. The patient initially responded to treatment with antibiotics and steroids, but experienced worsening after discontinuation of steroids. Brain biopsy performed to exclude central nervous system lymphoma produced nodular tissue with branching filaments on silver stain. Steroids were re-initiated and tapered slowly. The patient completed 1year of antibiotic therapy, after which he had no neurological symptoms and complete resolution of all brain abscesses on MRI.

Fatal nocardiosis in a dog caused by multiresistant Nocardia veterana.

Among pathogenic Nocardia species in humans and animals, infections caused by Nocardia (N.) veterana have rarely been described and so far, all non-human cases are linked to bovine mastitis in Brazil. The aim of this study was to identify the causative microorganism involved in the death of a three-month-old dog suffering from dyspnea and neurological deficits ante mortem. Pathomorphological investigation revealed (pyo-)granulomatous lesions in various organs. Bacteriological examination was performed and the respective bacteria were subjected to matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS), 16S rDNA sequencing, and antimicrobial susceptibility testing by broth microdilution. Gram-staining and colony morphology suggested the presence of an actinomycete which was identified as N. veterana by MALDI-TOF MS. This identification was confirmed by 16S rDNA sequence analysis. Distemper-associated immunosuppression may have played a role in the pathogenesis of systemic nocardiosis in this dog. Retrospective analysis of the antimicrobial susceptibility status showed that the N. veterana isolate was multiresistant and displayed high minimal inhibitory concentrations to all antimicrobial agents used for the dog's therapy. To the best of our knowledge, this is the first report of a systemic nocardiosis caused by N. veterana in a dog with a concurrent canine distemper virus infection.