Selenomethionine Mitigates Effects of Nocardia cyriacigeorgica-Induced Inflammation, Oxidative Stress, and Apoptosis in Bovine Mammary Epithelial Cells.

Nocardia cyriacigeorgica causes bovine mastitis, reduces milk quantity and quality, and is often resistant to antimicrobials. Selenomethionine (SeMet) is a form of selenium, which reduces reactive oxygen species (ROS)-mediated apoptosis and intramammary infections. However, the protective effects of SeMet on N. cyriacigeorgica-infected bovine mammary epithelial cells (bMECs) are unclear. The objective of this study was to evaluate whether SeMet mitigated N. cyriacigeorgica-induced inflammatory injury, oxidative damage and apoptosis in bMECs. Cells were cultured with or without being pretreated with 40 µM of SeMet for 12 h, then challenged with N. cyriacigeorgica (multiplicity of infection = 5:1) for 6 h. Although N. cyriacigeorgica was resistant to lincomycin, erythromycin, enrofloxacin, penicillin, amoxicillin, cephalonium, cephalexin, and ceftriaxone, 40 µM SeMet increased cell viability and inhibited lactate dehydrogenase release in infected bMECs. Furthermore, N. cyriacigeorgica significantly induced mRNA production and protein expression of TNF-α, IL-1ß, IL-6, and IL-8 at 6 h. Cell membrane rupture, cristae degeneration and mitochondria swelling were evident with transmission electron microscopy. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) activities were down-regulated after 3, 6, or 12 h, whereas malondialdehyde (MDA) and ROS contents were significantly upregulated, with cell damage and apoptosis rapidly evident (the latter increased significantly in a time-dependent manner). In contrast, bMECs pretreated with 40 µM SeMet before infection, SOD, and GSH-px activities were upregulated (p < 0.05); MDA and ROS concentrations were downregulated (p < 0.05), and apoptosis was reduced (p < 0.05). In conclusion, 40 µM SeMet alleviated inflammation, oxidative stress and apoptosis induced by N. cyriacigeorgica in bMECs cultured in vitro.

Nocardia cyriacigeorgica brain abscess with Pemphigus vulgaris: first report.

Nocardia brain abscess is an uncommon but potentially life threatening opportunistic infection that generally occurs in immunocompromised patients. Nocardia cyriacigeorgica is a recently described species rarely reported as a cause of human disease. Pemphigus vulgaris is managed with immunosuppression. There have been four prior reports of brain abscess caused by Nocardia cyriacigeorgica.

Multilocus sequence analysis (MLSA) of a Nocardia cyriacigeorgica strain causing severe bovine mastitis in Bosnia and Herzegovina.

Nocardia cyriacigeorgica is a well-known agent of human nocardiosis and is considered an emerging pathogen, however, its identification to the species level is complex for many clinical laboratories. Available data on the clinical significance of N. cyriacigeorgica in veterinary medicine are sparse and mainly concern isolated reports of pyogranulomatous lesions in domestic animals. We report a case of severe bovine mastitis caused by N. cyriacigeorgica that did not respond to conventional antimicrobial therapy in a small holding in Bosnia and Herzegovina. After isolation of the pathogen, further identification by routine microbiological methods was not possible. Susceptibility to antimicrobials was tested using the disc diffusion method according to published recommendations. The sample was also tested by MALDI-ToF MS with inconclusive results. In addition, 16S rRNA sequence analysis, verified by multilocus sequence analysis (MLSA) using the gyrB, 16S rRNA, secA1, and hsp65 sequences, confirmed the species N. cyriacigeorgica. To our knowledge, this is the first report of isolation of N. cyriacigeorgica from a clinical case of bovine mastitis in a European dairy farm and the first MLSA method approach to distinguish a Nocardia spp. strain isolated from animals.

Bacteremia and adrenal gland abscess due to Nocardia cyriacigeorgica: a case report and review.

BACKGROUND: Nocardia cyriacigeorgica is one of the most common Nocardia species found in human infections, recently reclassified. Even though Nocardia may affect all organs by hematogenous dissemination, bacteremia are uncommon. Among all possible dissemination sites, the involvement of the adrenal glands is particularly rare. CASE PRESENTATION: We report here a rare case of Nocardia disseminated infection with notably bacteremia and adrenal gland abscess, in a 77-years-old immunocompetent man. Adrenal gland abscess diagnosis was made by imaging (computerized tomography, magnetic resonance and positron emission tomography scan). A complete regression of all lesions including the left adrenal gland was obtained after 6 months of antibiotics. A review of literature was also performed. CONCLUSION: Nocardia bacteremia is a rare event but blood cultures may help to improve detection of Nocardia spp. in a non-invasive way. Adrenal abscess due to Nocardia spp. is very rare with only fourteen cases reported in the literature, but it is a true cause of adrenal masses. Our report suggests that clinician should be aware of this rare location and prioritize a non-invasive diagnosis strategy.

A challenging case of SARS-CoV-2- AIDS and Nocardiosis coinfection from the SMatteo COvid19 REgistry (SMACORE).

The COVID-19 pandemic is posing an unprecedented threat worldwide. One issue that has faltered, though, concerns the underestimated risk to trade all for COVID-19, misdiagnosing other potentially life-threatening diseases. Further still, the presence of respiratory symptoms in AIDS patients should stimulate more vigilant efforts to uncover other or additional infections. This case report highlights the pitfalls of diagnosing a rare pulmonary infection during the COVID-19 pandemic.

Microbiological profile of distinct virulence of Nocardia cyriacigeorgica strains in vivo and in vitro.

There are significant differences between different Nocardia species regarding geographical distribution, biochemical features, phenotypic characterization, and drug sensitivity. In this study, we explored the differences in virulence and pathogenic mechanisms of two Nocardia cyriacigeorgica strains. We examined the difference in virulence between N. cyriacigeorgica ATCC14759 and N. cyriacigeorgica GUH-2 by measuring cytotoxicity, animal survival after infection, the ability of host cell invasion, and viability in host cells. Western blotting was used to compare the differences in activation of MAPKs, including p38, ERK, and JNK, the NF-κB signaling pathway, and the PI3K/Akt signaling pathway in A549 and RAW264.7 cells. We measured the difference in stimulatory effects on production of the cytokines IL-6, IL-10, and TNF-α by ELISA. We found that N. cyriacigeorgica ATCC14759 causes higher cytotoxicity in cultured cells and higher lethality in mice, and exhibits superior invasion ability and viability in host cells compared with N. cyriacigeorgica GUH-2. Moreover, these two strains show marked differences in activation of the expression of cytokines and signaling pathways. N. cyriacigeorgica ATCC14759 is more virulent than N. cyriacigeorgica GUH-2. Furthermore, there is a significant difference in pathogenesis between the two strains. Our results provide a theoretical basis for the prevention and treatment of Nocardia infection.

Disseminated Nocardia infection with a lesion occupying the intracranial space complicated with coma: a case report.

BACKGROUND: Disseminated Nocardia infection is a disease that is easily overlooked in patients with lesions occupying the intracranial space complicated with coma. Early diagnosis and treatment are crucial. CASE PRESENTATION: A 65-year-old man was admitted to the First Affiliated Hospital of Zhejiang University in October 2018 with weakness in the right limbs for 3 days and altered consciousness for 1 day. Five months earlier, he had been diagnosed with membranous kidney disease and had received cyclophosphamide and prednisone. At admission, the white blood cell count was 1.37 × 1010/L (with 86.4% neutrophils), and C-reactive protein was 115.60 mg/L. Imaging examinations revealed a lesion occupying the intracranial space, lung infection, and multiple abscesses in the rhomboid muscle. The abscesses were drained. Pus culture confirmed Nocardia cyriacigeorgica infection. With antibiotics and vacuum-sealed drainage of the back wound, the patient improved and was discharged from the hospital. CONCLUSIONS: This case report shows that infection should be considered during the differential diagnosis of lesions in the intracranial space, especially in patients receiving immunosuppressive treatment. In patients with disseminated N. cyriacigeorgica infection, combination antibiotic therapy and surgical drainage of localised abscesses can be effective.

An unusual case of Nocardia cyriacigeorgica presenting with spinal abscesses in a renal transplant recipient and a review of the literature.

Nocardia species represent a well-recognized yet uncommon cause of opportunistic infections in humans. It most frequently presents as a pulmonary infection with or without central nervous system involvement. It is a very rare cause of spinal abscesses, with only 26 cases reported in the literature. Here we report a 49-year-old man with a history of renal transplantation who presented with low back pain and was diagnosed with epidural and paraspinal abscesses due to Nocardia cyriacigeorgica that was successfully treated with antimicrobial therapy alone. In addition to the case reported here, we also conducted a systematic review of the existing literature regarding spinal abscesses due to Nocardia species and examined the success of the various treatments utilized.

Systemic nocardiosis in a dog caused by Nocardia cyriacigeorgica.

BACKGROUND: Systemic nocardiosis due to Nocardia cyriacigeorgica has not been reported in dogs. CASE PRESENTATION: Light and electron microscopy, microbiological culture and molecular identification (PCR) were used to diagnose systemic nocardiosis caused by Nocardia cyriacigeorgica in a 3-month-old husky dog. The postmortem changes included multifocal to coalescing, sharply circumscribed pyogranulomatous inflammation and abscess formation in lungs, liver, myocardium, spleen, kidneys, brain, and hilar lymph nodes. The organism was isolated and sequencing of its 16S rRNA allowed its identification and speciation. Examination of the bacterial culture by scanning electron-microscope showed filamentous branching with fragmentation into widely bacillary and cocoid forms of the bacteria. There was no history of immunosupressive drug administration and infection by the immunosuppresive viral pathogens, canine distemper and parvovirus were excluded via PCR. CONCLUSION: N. cyriacigeorgica should be considered potential cause of systemic pyogranulomatous lesions in dogs. It is the first reported case of systemic nocardiosis due to N. cyriacigeorgica in a dog.

Short communication: Molecular characteristics, antimicrobial susceptibility, and pathogenicity of clinical Nocardia cyriacigeorgica isolates from an outbreak of bovine mastitis.

The occurrence of nocardial mastitis, mostly in the context of outbreaks, has been reported in many countries. However, there is a paucity of reports regarding detailed characterization of Nocardia cyriacigeorgica from bovine mastitis. Thus, herein we report characteristics, antimicrobial susceptibility patterns, molecular identification, and pathogenicity of N. cyriacigeorgica isolated from an outbreak of clinical mastitis in a dairy herd in northern China. A total of 182 (80.2%) lactating cows had clinical mastitis with severe inflammation and firmness of the udder, reduced milk production, and anorexia, with no apparent clinical response to common antibiotics. Out of 22 mastitic milk samples submitted to our laboratory, 12 N. cyriacigeorgica were isolated and characterized using standard microbiological analysis, 16S rRNA gene sequencing, random amplified polymorphic DNA PCR analysis, biochemical assays, and antibiotic susceptibility testing. Additionally, in vivo experiments were done to determine pathogenicity of these clinical mastitis isolates. All isolates were resistant to ampicillin, amoxicillin-clavulanic acid, ciprofloxacin, minocycline, rifampicin, and aminoglycosides (type VI pattern). Additionally, intramammary inoculation of mice with N. cyriacigeorgica caused chronic inflammatory changes, including hyperemia, edema, and infiltration of lymphocytes and neutrophils, as well as hyperplasia of lymph nodules in mammary glands. Therefore, we concluded that N. cyriacigeorgica was involved in the current outbreak of mastitis. To our best knowledge, this is the first report to characterize N. cyriacigeorgica isolated from cases of bovine mastitis in China.

Myasthenia gravis complicated with pulmonary infection by Nocardia cyriacigeorgica: a case report and literature review.

Myasthenia gravis (MG) is an autoimmune disease. Patients with MG due to compromised autoimmune regulation, progressive muscle weakness, and prolonged use of immunosuppressants and glucocorticoid, often present with concomitant infections. However, cases of MG complicated by Nocardia infection are rare. In this case, we report MG complicated with pulmonary infection by Nocardia cyriacigeorgica. A 71-year-old male farmer who was admitted for management of MG. After 7 weeks of treatment of MG, the patient reported improvement. However, clinical presentation, inflammatory markers, and imaging findings supported a diagnosis of pulmonary infection. To further elucidate the etiology, Nocardia was identified in sputum smear microscopy and sputum culture, with 16S rRNA gene sequencing confirming N. cyriacigeorgica. The patient was prescribed trimethoprim-sulfamethoxazole. After 1 month of treatment, clinical symptoms of MG and pulmonary nocardiosis showed significant improvement. Additionally, we searched PubMed for case reports of Nocardia cyriacigeorgica pulmonary infection from 2010 to 2024 and conducted a statistical analysis of the case information. This report aims to highlights the increased risk of pulmonary Nocardia infection in MG patients after the use of steroids and immunosuppressants, thereby enhancing clinical awareness.

A Case of Yellow Nail Syndrome Complicated with Pulmonary Infection Due to Nocardia cyriacigeorgica.

Yellow nail syndrome (YNS) is a rare clinical syndrome characterized by nail bed changes, pulmonary involvement, and lymphatic drainage disorders. Pulmonary involvement usually manifests as bronchiectasis, bronchiolitis, and pleural effusion. There are few studies on yellow nail syndrome combined with opportunistic infection. Here, we report a case of clinically diagnosed YNS combined with Nocardia cyriacigeorgica infection and the course of treatment used, which can provide some useful information for clinicians to better understand this rare illness.

Disseminated Nocardia cyriacigeorgica Infection Disguised as a Metastatic Adrenal Gland Malignancy in a Healthy Patient.

Nocardia, typically recognized as an uncommon opportunistic pathogen affecting immunocompromised individuals, has also been documented in various case reports involving infections in immunocompetent hosts. Transmission occurs through inhalation or inoculation into compromised skin. Subsequently, it can lead to disseminated infection via hematogenous spread, affecting nearly any organ with a particular affinity for the central nervous system. Dissemination to the adrenal glands is extremely rare, with only a few cases reported. In this report, we present a rare case of disseminated Nocardia cyriacigeorgica, initially resembling a metastatic adrenal gland malignancy in an otherwise healthy individual. The patient presented with non-specific symptoms, had multiple sets of negative blood cultures, clinical findings suggestive of an underlying adrenal gland malignancy, and lacked identifiable risk factors for Nocardia, creating a significant diagnostic challenge. Additionally, we review the existing literature on nocardiosis involving the adrenal glands. This case marks the third reported instance of a Nocardia cyriacigeorgica adrenal gland abscess in the literature.

Unusual Presentation of Nocardiosis With Pleural Effusion in an Immunocompetent Host.

Nocardiosis is a disease caused by gram-positive, catalase-positive, rod-shaped bacteria that stain weakly on a Gram stain. It usually affects the lungs and skin but can cause disseminated infections. Nocardia has 85 species, ranging from nonpathogenic to pathogenic. Nocardia is an opportunistic organism that causes infections in the immunocompromised; however, 7% of the immunocompetent population has suffered from Nocardia infection. This case report highlights an unusual occurrence of pulmonary nocardiosis in a 31-year-old woman with a normal immune system. She was initially treated as an outpatient for what appeared to be community-acquired pneumonia. However, her condition deteriorated, ultimately revealing a substantial right pleural effusion with loculation and adjacent compressive atelectasis affecting a significant portion of her right middle and lower lung lobes, as detected by a CT scan followed by pleural fluid analysis which confirmed the infection. By sharing this experience, we aim to contribute to the collective knowledge of medical professionals and improve the accuracy of diagnosis and treatment.

Interstitial pneumonia combined with nocardia cyriacigeorgica infection: A case report.

BACKGROUND: Nocardia infection is a relatively uncommon disease, with no reports among patients with interstitial pneumonia. Due to its atypical clinical symptoms and chest computed tomography (CT) findings and the frequent yielding of negative results by conventional cultures, it poses challenges for timely diagnosis and treatment. CASE SUMMARY: A 63-year-old female patient presented to our hospital in July 2022 with a 3-mo history of intermittent cough and poor appetite, accompanied by a 2-wk long duration of headaches. She had a previous medical history of interstitial pneumonia and was on oral prednisone and cyclosporine. Chest CT revealed the presence of newly developed round nodules. The diagnosis of Nocardia cyriacigeorgica infection was confirmed through metagenomic next-generation sequencing (mNGS) performed on bronchoalveolar lavage fluid. Targeted anti-infection therapy was initiated, resulting in symptom improvement and radiological resolution, further validating the mNGS results. CONCLUSION: Nocardia cyriacigeorgica infection is a clinically rare condition that is primarily observed in immunocompromised patients. Its clinical and radiological manifestations lack specificity, but mNGS can aid in rapidly obtaining pathogenic information. Early initiation of targeted antimicrobial therapy based on mNGS results can improve patient prognosis.

A post-transplant infection by Nocardia cyriacigeorgica.

Nocardia are Gram-positive, acid-fast, filamentous bacteria that cause opportunistic infections in susceptible populations. We describe a case of post-transplant infection of pulmonary nocardiosis caused by the rare strain Nocardia cyriacigeorgica and the challenges faced in reaching a definitive diagnosis. This case report emphasizes on keeping nocardiosis as a differential diagnosis in transplant recipients, as this disease is largely underdiagnosed and underreported.

Subretinal abscess due to nocardia in an immunosuppressed patient: a case report.

Systemic nocardiosis is a rarely occurring pathology, but its hematogenous spread across the eye is even less likely to occur, with only a few recorded cases. Therefore, it is not usually taken into account when a subretinal abscess is being considered for a diagnosis. However, when confronting a case with a history of immunosupression and pulmonary disease, the examination of the ocular fundus may be a very successful approach. With such aim we introduce the case of a 45-year-old immunosupressed male, without a history of pulmonary disease, whose subretinal mass evolution is accordant with an abscess. In the end, being etiologically diagnosed by means of a vitrectomy, it was concluded that the abscess was due to an infection of nocardia cyriacigeorgica, an emergent pathogen. Thus the aforementioned case is to be considered in the present study, along others, in order to shed more light on a disease which may not be readily diagnosed on account of its infrequency.

A Rare Case of a Subcutaneous Abscess Caused by Nocardia cyriacigeorgica in an Immunocompetent Patient.

Background: Nocardia cyriacigeorgica, which mainly causes pleuropulmonary and disseminated nocardiosis, has been proved to be one of the most common opportunistic pathogens in patients with immunodeficiency, but the cases that cause subcutaneous abscesses in normal individuals are rare and should be paid attention to. Methods: The clinical data of a patient with cutaneous nocardiosis caused by Nocardia cyriacigeorgica in Zhejiang Provincial People's Hospital were retrospectively analyzed, including clinical manifestations, laboratory examinations, imaging examinations, medication and prognosis. Results: Magnetic resonance imaging (MRI) showed that there was a 26 mm × 73 mm abscess under the skin. The pus in the abscess was green. Gram staining showed positive branched rod-shaped and undivided hyphae. After culture, small wrinkle dry white small colonies were observed, and it was identified as Nocardia cyriacigeorgica by MALDI-TOF MS. Conclusion: We report the first case of a subcutaneous abscess caused by Nocardia cyriacigeorgica in an immunocompetent patient. Compared with cutaneous nocardiosis of which approximately 80% caused by Nocardia brasiliensis invasion, infection of Nocardia cyriacigeorgica is more insidious and latent, the features of the lesions are also unique. For this Nocardia cyriacigeorgica clinical isolate, the tested antibacterial drugs are generally sensitive and have an ideal prognosis after treatment with linezolid and timely debridement.

Nocardia cyriacigeorgica infection in a patient with repeated fever and CD4+ T cell deficiency: A case report.

BACKGROUND: Nocardia pneumonia shares similar imaging and clinical features with pulmonary tuberculosis and lung neoplasms, but the treatment and anti-infective medication are completely different. Here, we report a case of pulmonary nocardiosis caused by Nocardia cyriacigeorgica (N. cyriacigeorgica), which was misdiagnosed as community-acquired pneumonia (CAP) with repeated fever. CASE SUMMARY: A 55-year-old female was diagnosed with community-acquired pneumonia in the local hospital because of repeated fever and chest pain for two months. After the anti-infection treatment failed in the local hospital, the patient came to our hospital for further treatment. Enhanced computed tomography showed multiple patchy, nodular and strip-shaped high-density shadows in both lungs. A routine haematological examination was performed and showed abnormalities in CD19+ B cells and CD4+ T cells. Positive acid-fast bifurcating filaments and branching gram-positive rods were observed in the bronchoalveolar lavage fluid of the patient under an oil microscope, which was identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry as N. cyriacigeorgica. The patient's condition quickly improved after taking 0.96 g compound sulfamethoxazole tablets three times a day. CONCLUSION: The antibiotic treatment of Nocardia pneumonia is different from that of common CAP. Attention should be given to the pathogenic examination results of patients with recurrent fever. Nocardia pneumonia is an opportunistic infection. Patients with CD4+ T-cell deficiency should be aware of Nocardia infection.

Pneumococcal Pneumonia Co-infection with Mycobacterium avium and Nocardia cyriacigeorgica in an Immunocompetent Patient.

A 61-year-old woman was transferred with a complaint of a fever and productive cough. She had tested positive for Mycobacterium avium and Nocardia cyriacigeorgica at least twice, and Streptococcus pneumonia (PISP) was isolated (3+) from her purulent sputum. As radiological findings, a lower lung field-dominant infiltration shadow and nodular shadow with cavity were recognized in the bilateral lung fields. We diagnosed her with pneumococcal pneumonia co-infection with M. avium and N. cyriacigeorgica. She was treated with MEPM for pneumococcal pneumonia, a standard regimen containing clarithromycin for pulmonary M. avium complex (MAC) disease, and sulfamethoxazole/trimethoprim for pulmonary nocardiosis. She improved with appropriate treatment.