Pulmonary nocardiosis: risk factors, clinical features, diagnosis and prognosis

Nocardia farcinica infection presenting as a solitary bronchial neoplasm in an immunocompetent adult: a case report

Nocardia species are gram-positive, acid-fast, saprophytic, aerobic bacilli, predominantly resulting in opportunistic infections in immunocompromised individuals. Here, we reported a case of Nocardia infection in a 27-year-old woman with normal immunocompetence, who presented as a solitary neoplasm in the left principal bronchus with a chief complaint of postural dyspnea. By electrotomy via bronchoscopy, the neoplasm was successfully removed, and it was further identified as Nocardia farcinica by metagenomic next-generation sequencing.

Rare occurrence of pulmonary coinfection involving Aspergillus fumigatus and Nocardia cyriacigeorgica in immunocompetent patients based on NGS: A case report and literature review

RATIONALE

In our search on PubMed, we found that reports of co-infections involving Aspergillus fumigatus and Nocardia cyriacigeorgica in the literature are notably scarce. Most cases have been documented in patients with compromised immune systems or underlying pulmonary conditions. In contrast, our patient did not present with any of these risk factors. Furthermore, there have been no recent incidents such as near-drowning or other accidents in the patient history. To the best of our knowledge, this case represents a hitherto unreported clinical scenario. To enhance comprehension, we conducted a comprehensive literature review by compiling a total of 20 case reports (spanning from 1984 to 2023) on co-infections involving Aspergillus and Nocardia species, retrieved from PubMed.

PATIENT CONCERNS AND DIAGNOSIS

Chest CT revealed the presence of multiple nodules and clustered high-density shadows in both lungs. Bronchoscopy revealed mucosal congestion and edema in the apical segment of the right upper lobe of the lung, along with the presence of 2 spherical polypoid new organisms. The pathological analysis reported severe chronic inflammation with evidence of Aspergillus within the tissue. Next-Generation Sequencing of bronchoalveolar lavage fluid revealed the presence of reads corresponding to A fumigatus and N cyriacigeorgica. Positive cultures for A fumigatus and the Nocardia genus were yielded by prolonging the incubation of samples in the microbiology laboratory.

INTERVENTIONS

Treatment with voriconazole for A fumigatus and sulfamethoxazole-trimethoprim for N cyriacigeorgica infection was given.

OUTCOMES

The patient improved and was discharged. After 6 months of telephone follow-up, the patient reported no clinical symptoms, discontinued the medication on his own.

LESSONS

A fumigatus and N cyriacigeorgica can manifest as a co-infection in immunocompetent patients. Clinicians should prioritize the significant advantages and value of NGS in detecting rare and mixed pathogens associated with pulmonary infections.

Mild Pulmonary Nocardiosis Caused by Nocardia terpenica in an Immunocompetent Patient

A 53-year-old immunocompetent man was admitted to our hospital because of paroxysmal cough with a low fever for more than 5 months. On admission, chest computed tomography showed multiple plaques and nodules, some with small central cavities, in both lungs and cystic and columnar bronchiectasis of the right middle bronchus. Treatment with various antibiotics was ineffective. Metagenomic next-generation sequencing of the bronchoalveolar lavage fluid showed Nocardia terpenica, and this organism was cultured from bronchoalveolar lavage fluid, resulting in a diagnosis of pulmonary nocardiosis. After administration of trimethoprim-sulfamethoxazole for 5 weeks, chest computed tomography showed a significant reduction in the lung lesions that had been detected on admission. Immunosuppressed patients are particularly prone to nocardiosis infection, which is usually severe. N. terpenica has rarely been detected in clinical samples, and its characteristics require further study with the accumulation of more clinical cases.

Pulmonary nocardiosis following COVID-19 in a patient with idiopathic pulmonary fibrosis and lung transplantation: a case report

Background

Nocardiosis is an opportunistic infection that primarily affects immunocompromised patients. Pulmonary nocardiosis is the most prevalent form, but can also spread to other organs. Potential causes contributing to opportunistic infection may include immunosuppression and disruption of tight junctions, both of which can result from COVID-19.

Case presentation

We reported a case of a 68-year-old male patient who presented with a 10-day history of fever, cough, and productive sputum. Upon physical examination, velcro rales were detected in the right lung, while breath sounds in the left lung were clear. The patient had previously undergone left lung transplantation due to idiopathic pulmonary fibrosis four years ago. He was initially hospitalized and treated for COVID-19 but was readmitted due to worsening symptoms. Subsequently, pulmonary nocardiosis was diagnosed utilizing metagenomic next-generation sequencing of bronchoalveolar lavage fluid. The above-mentioned condition was improved following treatment with cancidas and linezolid. Now, he is under regular follow-up.

Conclusion

This case highlights the complexity of COVID-19 and the occurrence of secondary opportunistic infections, which require further investigation.

Hidden Behind a Veil: A Rare Case of Pulmonary Nocardiosis

A 48-year-old male, a known case of seizure disorder, presented with complaints of cough for four months, which increased for two weeks, fever for two weeks and weight loss. Computed tomography (CT) scan of the thorax showed multiple heterogeneously enhancing lesions of bilateral lung fields predominantly in peribronchovascular distribution with enlarged, necrosed and conglomerated lymph nodes suggestive of infective etiology. On routine blood investigations, he was found to be reactive for the human immunodeficiency virus. He underwent bronchoscopy and bronchoalveolar lavage culture grew Nocardia. He was prescribed antibiotics based on susceptibility reports and the patient became symptomatically better after one month and was discharged.

Pulmonary nocardiosis with bloodstream infection diagnosed by metagenomic next-generation sequencing in a kidney transplant recipient: A case report

BACKGROUND

Pulmonary nocardiosis is difficult to diagnose by culture and other conventional testing, and is often associated with lethal disseminated infections. This difficulty poses a great challenge to the timeliness and accuracy of clinical detection, especially in susceptible immunosuppressed individuals. Metagenomic next-generation sequencing (mNGS) has transformed the conventional diagnosis pattern by providing a rapid and precise method to assess all microorganisms in a sample.

CASE SUMMARY

A 45-year-old male was hospitalized for cough, chest tightness and fatigue for 3 consecutive days. He had received a kidney transplant 42 d prior to admission. No pathogens were detected at admission. Chest computed tomography showed nodules, streak shadows and fiber lesions in both lung lobes as well as right pleural effusion. Pulmonary tuberculosis with pleural effusion was highly suspected based on the symptoms, imaging and residence in a high tuberculosis-burden area. However, anti-tuberculosis treatment was ineffective, showing no improvement in computed tomography imaging. Pleural effusion and blood samples were subsequently sent for mNGS. The results indicated Nocardia farcinica as the major pathogen. After switching to sulphamethoxazole combined with minocycline for anti-nocardiosis treatment, the patient gradually improved and was finally discharged.

CONCLUSION

A case of pulmonary nocardiosis with an accompanying bloodstream infection was diagnosed and promptly treated before the dissemination of the infection. This report emphasizes the value of mNGS in the diagnosis of nocardiosis. mNGS may be an effective method for facilitating early diagnosis and prompt treatment in infectious diseases, which overcomes the shortcomings of conventional testing.

The Computed Tomography Findings and Follow-up Course of Pulmonary Nocardiosis

OBJECTIVE

Our study aimed to elucidate the computed tomography (CT) features and follow-up course of pulmonary nocardiosis patients to improve the understanding and diagnostic accuracy of this disease.

METHODS

The chest CT findings and clinical data of patients diagnosed with pulmonary nocardiosis by culture or histopathological examination in our hospital between 2010 and 2019 were retrospectively analyzed.

RESULTS

A total of 34 cases of pulmonary nocardiosis were included in our study. Thirteen patients were on long-term immunosuppressant therapy, among whom 6 had disseminated nocardiosis. Among the immunocompetent patients, 16 had chronic lung diseases or a history of trauma. Multiple or solitary nodules represented the most common CT feature (n = 32, 94.12%), followed by ground-glass opacities (n = 26, 76.47%), patchy consolidations (n = 25, 73.53%), cavitations (n = 18, 52.94%), and masses (n = 11, 32.35%). There were 20 cases (61.76%) with mediastinal and hilar lymphadenopathy, 18 (52.94%) with pleural thickening, 15 (44.12%) with bronchiectasis, and 13 (38.24%) with pleural effusion. Significantly higher rates of cavitations were observed among immunosuppressed patients (85% vs 29%, P = 0.005). At follow-up, 28 patients (82.35%) clinically improved with treatment, while 5 (14.71%) had disease progression, and 1 (2.94%) died.

CONCLUSIONS

Chronic structural lung diseases and long-term immunosuppressant use were found as risk factors for pulmonary nocardiosis. While the CT manifestations were highly heterogeneous, clinical suspicion should be raised upon findings of coexisting nodules, patchy consolidations, and cavitations, particularly in the presence of extrapulmonary infections such as those of the brain and subcutaneous tissues. A significant incidence of cavitations may be observed among immunosuppressed patients.

Rapid detection of pulmonary nocardiosis by metagenomic next generation sequencing

We retrospectively analyzed 3 cases of pulmonary nocardiosis. Patients were identified by metagenomic next generation sequencing (mNGS) in the First Affiliated Hospital of Soochow University, from January 2019 to April 2022. All patients had underlying diseases, and were in immunocompromised state, with membranous nephropathy, acute lymphoblastic leukemia (ALL), and systemic lupus erythematosus (SLE), respectively. Symptoms common to all cases included fever, cough and expectoration. Chest computed tomography (CT) presented patchy shadows or nodules, with or without cavitation lesions, or pleural effusion. mNGS detected Nocardia spp. via bronchoalveolar lavage fluid (BALF) or blood samples from patients. All the patients were discharged with recovery after using the trimethoprim-sulfamethoxazole (TMP-SMX) and remained without evidence of disease during regular follow-ups. mNGS may be a tool for rapid and accurate detection and identification of pulmonary nocardiosis, but interpreting the mNGS results should be more cautious because the mNGS assay can also detect colonization.

Clinical characteristics and treatment strategy of nocardiosis in lung transplant recipients: a single-center experience

Objective

Nocardia are infrequent pathogens that disproportionately afflict organ transplant recipients. The present study aimed to summarize the clinical manifestations, diagnostic approaches, and treatment strategies of nocardiosis in lung transplant recipients.

Methods

This retrospective study reviewed the clinical data of adult lung transplant recipients who were complicated with nocardiosis between January 2018 and December 2021 at the largest lung transplant center in South China.

Results

The incidence of nocardiosis was 4.2% (13/316), including 9 cases of pulmonary nocardiosis and 4 disseminated nocardiosis (blood, pulmonary and intracranial). The accuracy in diagnosing nocardiosis was 77.8% by culture and 100% by metagenomic next-generation sequencing (mNGS). Nocardia farcinica was the most common causative pathogen. Trimethoprim-sulfamethoxazole-based combination therapy was administered initially, followed by a single antibiotic as the maintained therapy, lasting for 4-8 months.

Conclusions

mNGS is more accurate than culture in diagnosing nocardiosis. Most patients responded well to the antibiotic therapy with combined antibiotics at the initial stage followed by a single antibiotic treatment.

Updated Review on Nocardia Species: 2006-2021

This review serves as an update to the previous Nocardia review by Brown-Elliott et al. published in 2006 (B. A. Brown-Elliott, J. M. Brown, P. S. Conville, and R. J. Wallace. Jr., Clin Microbiol Rev 19:259-282, 2006, https://doi.org/10.1128/CMR.19.2.259-282.2006). Included is a discussion on the taxonomic expansion of the genus, current identification methods, and the impact of new technology (including matrix-assisted laser desorption ionization-time of flight [MALDI-TOF] and whole genome sequencing) on diagnosis and treatment. Clinical manifestations, the epidemiology, and geographic distribution are briefly discussed. An additional section on actinomycotic mycetoma is added to address this often-neglected disease.

Case report: Nocardial brain abscess in a persistently SARS-CoV-2 PCR positive patient with systemic lupus erythematosus

Coronavirus disease (COVID-19) in immunocompromised patients represents a major challenge for diagnostics, surveillance, and treatment. Some individuals remain SARS-CoV-2 PCR-positive for a prolonged period. The clinical and epidemiological significance of this phenomenon is not well understood. We report a case of a patient with a history of systemic lupus erythematosus (SLE) who has been persistently SARS-CoV-2 PCR positive for 9 months, with multiple thromboembolic complications, and development of nocardial brain abscess successfully treated with surgery and antibiotics.

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% 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<.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 linked to 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 in an Immunocompetent Host Masquerading As Lung Cancer: A Case Report

Nocardiosis is generally regarded as an opportunistic infection that can present as a cutaneous, pulmonary, or disseminated disease based on host immunity status. Pulmonary nocardiosis is typically seen in immunocompromised patients; however, it can rarely be present in immunocompetent patients. We present a rare case of an immunocompetent patient who was thought to have a lung malignancy but was found to have pulmonary nocardiosis upon further investigation.

Nocardiosis: When the Side Effects of Therapy Mimic Symptoms

Nocardiosis is a rare infection caused by gram-positive aerobic actinomycetes, which are common in soil. Inoculation occurs by inhaling agent fragments that cause localized or systemic suppurative lesions. The diagnosis is established based on isolation in cultural examinations. Trimethoprim-sulfamethoxazole (TMP-SMX) is the first-line treatment, and an antimicrobial susceptibility test is useful in severe cases or when there is no clinical response. The duration of treatment is determined by the affected site. However, the treatment cycles are long, and recurrence is common, which has a negative impact on the prognosis.

We describe a case of an immunocompetent male with a recent diagnosis of pulmonary nocardiosis who, after starting therapy, presented with symptoms that could be explained by either disease progression or an adverse pharmacological reaction. Throughout this case, with atypical evolution, the authors review the diagnostic and therapeutic approach to Nocardia infection and alert to the importance of the differential diagnosis and available therapeutic options.

Case Report: Disseminated Nocardiosis Caused by Nocardia vulneris in a Patient With Macroglobulinemia

This report describes a case of disseminated nocardiosis, caused by Nocardia vulneris, in a 61-year-old man with macroglobulinemia and presenting with repeated fever, cough, shortness of breath, and muscle pain. The isolated Nocardia strain was resistant to ciprofloxacin, but susceptible to amikacin, gentamicin, tobramycin, linezolid, trimethoprim-sulfamethoxazole, amoxicillin/clavulanic, moxifloxacin, ceftriaxone, cefotaxim, and imipenem. The patient was started on combined meropenem and doxycycline treatment, followed by trimethoprim-sulfamethoxazole, which was subsequently switched to a combination treatment of linezolid, amikacin, and trimethoprim-sulfamethoxazole. The patient recovered, and his condition remained stable. Although infection by Nocardia vulneris is rare, and it is easy to miss detection in clinical practice, clinicians should be aware of the possibility of this infection. In addition, the MIC value of the drug sensitivity test should be ascertained when there is a wide choice of medicines. The current case was treated successfully with linezolid, amikacin, and trimethoprim-sulfamethoxazole. In cases of disseminated nocardiosis, the patient should be treated with antimicrobial therapy for at least 12 months. Furthermore, bacteriological examination and antimicrobial susceptibility testing should be performed regularly.

A Case of Asymptomatic Pulmonary Nocardia cyriacigeorgica Infection With Mild Diabetes Mellitus

Nocardiosis is a relatively rare opportunistic infection, ranging from localized to systemic diseases, commonly occurring in immunocompromised patients with high mortality rates. We present a case of a 61-year-old man who received medical treatment for type 2 diabetes mellitus and underwent a physical examination that showed abnormal chest shadows on radiography. Chest computed tomography revealed bronchiectasis and infiltration in the left lower lobe. Nocardia spp. was detected in the bronchial washes, and he was started on sulfamethoxazole-trimethoprim under the diagnosis of pulmonary nocardiosis. 16S ribosomal RNA gene sequencing analysis identified the species as Nocardia cyriacigeorgica. His pulmonary lesions successfully improved after treatment for six months. Pulmonary nocardiosis often presents with symptoms such as hemoptysis and blood-tinged sputum, and bronchiectasis has been identified as an underlying condition. Even in hosts without underlying immunocompromising conditions, Nocardia spp. can be a causative microorganism of pulmonary infections, and it should be considered in the differential diagnoses.

Septic arthritis due to Nocardia brasiliensis and a review of nocardiosis as a cause of arthritis

Bacteria of the genus Nocardia are implicated in several disease processes but are a rare cause of septic arthritis. Typically, the cause of Nocardia septic arthritis is dissemination from a pulmonary infection in an immunocompromised host. Herein we present a case of a 64-year-old male who had received a long course of prednisone for membranous nephropathy and developed a septic arthritis due to Nocardia brasiliensis. He was treated sequentially with trimethoprim-sulfamethoxazole and amoxicillin-clavulanate, linezolid and amoxicillin-clavulanate, tigecycline and amoxicillin-clavulanate, and omadacycline and amoxicillin-clavulanate. To our knowledge, only two prior cases of Nocardia brasiliensis septic arthritis without antecedent trauma to the joint or local skin breakdown have been reported. A review of the literature identified 19 other cases of Nocardia septic arthritis. This case reinforces the need to consider Nocardia infection in the differential diagnosis in the immunocompromised patient with concurrent pulmonary infection and septic arthritis.

Disseminated Nocardia farcinica involves the spinal cord: a case report and review of the literature

Background

Nocardia is a relatively rare opportunistic pathogenic bacteria group, commonly seen in patients with immunocompromised or defective immune system. It can affect multiple organs of the body and cause disseminated infection, among which most occurs in the lung, secondly in the nervous system, soft tissues, rare in the spinal cord and pituitary. No case has been reported involving lung, spinal cord, skin and pituitary gland at the same time.

Case presentation

We report a 55-year-old female with Nocardia infection involving the lung, skin, spinal cord, and pituitary gland. The patient underwent a full set of imaging examinations and showed typical imaging findings. Chest computed tomography (CT) showed multiple nodules with cavities in the lungs. The magnetic resonance imaging (MRI) of the vertebral body showed abnormal signal of the entire spinal cord with cavity formation and ring enhancement. The subcutaneous nodules of the abdomen were punctured under ultrasound. Through the etiological tissue culture of subcutaneous nodules and the second generation sequencing of cerebrospinal fluid, the diagnosis was finally confirmed.

Conclusion

Disseminated Nocardiosis is an uncommon disease. This article will report a rare case of disseminated Nocardiosis simultaneously involving the lung, spinal cord, subcutaneous soft tissue and pituitary gland, especially with neuropathy as the initial symptom. Imaging is helpful for the early diagnosis of the disease and pathological and microbiological examinations are helpful for its confirming.

Localized Pulmonary Nocardia farcinica Infection As the Presenting Symptom of Acquired Immunodeficiency Syndrome

Nocardiosis is an opportunistic infection that most commonly affects immunocompromised patients, with clinical presentations ranging from localized to disseminated disease. In the United States, the reported incidence is approximately 500 to 1,000 cases per year, with an observed male-to-female predominance of 3:1. We present the case of a 37-year-old male with a past medical history of malaria who presented with watery, non-bloody diarrhea for four days associated with a fever for two weeks. The human immunodeficiency virus (HIV) was positive in the emergency room before admission. Computerized tomography (CT) of the chest with contrast revealed an irregular pleural base mass in the right lower lobe with several small air foci. CT of the abdomen and pelvis revealed the right pleural base lung mass to be adherent to the diaphragm, as well as mild splenomegaly. The cluster of differentiation 4 (CD4) count was 9 cells/mm³. An acid-fast bacilli (AFB) sputum culture was positive for Nocardia farcinica. Trimethoprim-sulfamethoxazole was started for a Nocardia farcinica pulmonary infection, in addition to antiretroviral therapy. The patient was strongly encouraged to follow-up at the outpatient department.

Misdiagnosed tuberculosis being corrected as Nocardia farcinica infection by metagenomic sequencing: a case report

Background

Disseminated nocardiosis is liable to be misdiagnosed owing to the non-specific clinical manifestations and laboratory/imaging findings. Metagenomic next-generation sequencing (mNGS) is a culture-independent and rapid method for direct identification of all microorganisms in clinical specimens.

Case presentation

A 72-year-old man was admitted to our hospital on February 20, 2019 with a history of recurrent cough, expectoration, fever, and diarrhea since 1 month, and unconsciousness since 1 week. Contrast-enhanced magnetic resonance imaging of head showed multiple lesions in the bilateral cerebral hemispheres, brainstem, and cerebellar hemispheres. The presumptive diagnosis was disseminated tuberculosis, although all tests for mycobacterium were negative. However, the patient did not benefit from antituberculosis treatment. Repeat MRI showed multiple abnormal signals in the brain and progression of meningeal thickening. Cerebrospinal fluid and bronchoalveolar lavage fluid specimens were subsequently sent for PMSeq metagenomics sequencing; the results indicated Nocardia. farcinica as the predominant pathogen. The anti-TB treatment was stopped and the patient was prescribed sulphamethoxazole in combination with linezolid and meropenem for nocardiosis. He showed gradual neurological improvement and was transferred to Huashan Hospital. He was discharged from the hospital on April 19, 2019, but died of persistent diarrhea on May 26, 2019.

Conclusions

Patients with suspected nocardiosis do not always respond to conventional treatment; therefore, mNGS can facilitate diagnosis and timely treatment decision-making.

Nocardia cyriacigeorgica infection in a patient with pulmonary sequestration: A case report

BACKGROUND

Nocardia cyriacigeorgica (N. cyriacigeorgica) infection is uncommon in clinical practice. Pulmonary sequestration complicated with N. cyriacigeorgica has not been reported in the literature. Here, we present a case of pulmonary se-questration complicated with N. cyriacigeorgica infection in an immunocom-petent woman.

CASE SUMMARY

A 37-year-old woman complaining of a recurrent cough was admitted to our hospital. Pulmonary sequestration in the lower lobe of the left lung was diagnosed by enhanced computed tomography. Bronchoalveolar lavage fluid was then collected, which showed gram positive bacilli with weakly positive modified acid-fast staining. The pathogen was identified as N. cyriacigeorgica after bacterial culture and mass spectrometry analysis. The patient was diagnosed with pulmonary sequestration complicated with N. cyriacigeorgica infection, and her symptoms quickly improved following anti-infective therapy.

CONCLUSION

Nocardiosis is considered to be an opportunistic infection. This is the first report of pulmonary sequestration complicated with N. cyriacigeorgica infection in a patient with normal immunity.

Cushing's Syndrome With Nocardiosis: A Case Report and a Systematic Review of the Literature

OBJECTIVE

To analyze and summarize the clinical characteristics, treatments, and prognosis of Cushing's syndrome (CS) with nocardiosis.

METHODS

A patient in our hospital and additional 17 patients of CS with nocardiosis in the English literature were included in this study. Clinical characteristics, laboratory data, imaging studies, treatments, and prognosis were evaluated.

RESULTS

A 41-year-old man with CS was diagnosed and treated in our hospital. He had co-infections of nocardiosis and aspergillosis. Together with 17 patients of CS with nocardiosis in the English literature, 2 patients (11.1%) were diagnosed as Cushing's disease (CD) while 16 (88.9%) were diagnosed or suspected as ectopic ACTH syndrome (EAS). The average 24hrUFC was 7,587.1 ± 2,772.0 μg/d. The average serum total cortisol and ACTH (8 AM) was 80.2 ± 18.7 μg/dl and 441.8 ± 131.8 pg/ml, respectively. The most common pulmonary radiologic findings in CT scan were cavitary lesions (10/18) and nodules (8/18). Co-infections were found in 33.3% (6/18) patients. The CS patients with co-infections had higher levels of ACTH (671.5 ± 398.2 vs 245.5 ± 217.1 pg/ml, P = 0.047), and 38.9% (7/18) patients survived through the antibiotic therapy and the treatment of CS. Patients with lower level of ACTH (survival vs mortality: 213.1 ± 159.0 vs 554.7 ± 401.0 pg/ml, P = 0.04), no co-infection, underwent CS surgery, and received antibiotic therapy for more than 6 months, had more possibilities to survive.

CONCLUSIONS

Nocardia infection should be cautioned when a patient of CS presented with abnormal chest radiographs. The mortality risk factors for CS with nocardiosis are high level of ACTH and co-infections. We should endeavor to make early etiological diagnosis, apply long-term sensitive antibiotics and aggressive treatments of CS.

Efficient differentiation of Nocardia farcinica, Nocardia cyriacigeorgica and Nocardia beijingensis by high-resolution melting analysis using a novel locus

Accurate identification of Nocardia species remains a challenge due to the complexities of taxonomy and insufficient discriminatory power of traditional techniques. We report the development of a molecular technique that utilizes real-time PCR-based high-resolution melting (HRM) analysis for differentiation of the most common Nocardia species. Based on a novel fusA-tuf intergenic region sequence, Nocardia farcinica, Nocardia cyriacigeorgica and Nocardia beijingensis were clearly distinguished from one another by HRM analysis. The limit of detection of the HRM assay for purified Nocardia spp. DNA was at least 10 fg. No false positives were observed for specificity testing of 20 non-target clinical samples. In comparison to established matrix-assisted laser desorption/ionization-time of flight MS, the HRM assay improved the identification of N. beijingensis. Additionally, all the products of PCR were verified by direct sequencing. In conclusion, the developed molecular assay allows simultaneous detection and differentiation of N. farcinica, N. cyriacigeorgica and N. beijingensis with high sensitivity and specificity.

A Rare Case of Drug-Resistant Nocardia transvalensis Infection in a Renal Transplant Patient

Nocardia transvalensis is a rare species of Nocardia and is known to be a drug-resistant organism. Multiple cases have been reported of Nocardia species causing opportunistic infections in immunocompromised hosts. To our knowledge, we report the first case of successfully treated drug-resistant Nocardia transvalensis causing pulmonary nocardiosis in a renal transplant patient. Our case validates the importance of prompt identification of Nocardia species and their drug sensitivities to improve clinical outcomes and reduce mortality.

Acute and Chronic Respiratory Failure in Cancer Patients

In 2016, there was an estimated 1.8 million new cases of cancer diagnosed in the United States. Remarkable advances have been made in cancer therapy and the 5-year survival has increased for most patients affected by malignancy. There are growing numbers of patients admitted to intensive care units (ICU) and up to 20% of all patients admitted to an ICU carry a diagnosis of malignancy. Respiratory failure remains the most common reason for ICU admission and remains the leading causes of death in oncology patients. There are many causes of respiratory failure in this population. Pneumonia is the most common cause of respiratory failure, yet there are many causes of respiratory insufficiency unique to the cancer patient. These causes are often a result of immunosuppression, chemotherapy, radiation treatment, or hematopoietic stem cell transplant (HCT). Treatment is focused on supportive care and specific therapy for the underlying cause of respiratory failure. Noninvasive modalities of respiratory support are available; however, careful patient selection is paramount as indiscriminate use of noninvasive positive pressure ventilation is associated with a higher mortality if mechanical ventilation is later required. Historically, respiratory failure in the cancer patient had a grim prognosis. Outcomes have improved over the past 20 years. Survivors are often left with significant disability.

Species Distribution And Antibiotic Susceptibility Of Nocardia Isolates From Yantai, China

Purpose

This study aimed to investigate the species distributions and drug sensitivities among 19 strains of Nocardia isolated from Yantai, China, from 2017 to 2019.

Patients and methods

Definitive species identification was performed by sequencing a fragment of the 16S rRNA gene (1480 bp) and by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). The susceptibilities of the isolates to 15 commonly-used antibiotics were tested using the microbroth dilution method.

Results

Among the 19 Nocardia isolates, five species were confirmed. Seventeen of the 19 Nocardia spp. strains were identified consistently by the two methods, while two isolates of N. cyriacigeorgica were misidentified as N. otitidiscaviarum by MALDI-TOF MS. N. farcinica was the most common species (8/19), followed by N. cyriacigeorgica (6/19), N. otitidiscaviarum (2/19), N. brasiliensis (2/19), and N. nova (1/19). All isolates were susceptible to trimethoprim-sulfamethoxazole and amikacin, followed by linezolid and tigecycline (94.7% susceptibility rates). The sensitivity and minimum inhibitory concentration patterns for ciprofloxacin, moxifloxacin, clarithromycin, and tobramycin were significantly correlated with the species.

Conclusion

These results regarding the distribution and antibiotic resistance features of Nocardia species further our understanding of the diversity of Nocardia species circulating in Yantai, China, and thus support the use of more accurate empirical treatments.

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.

Treatment of cardiac nocardiosis in a post-renal transplant patient of systemic nocardiosis

In general, nocardia infects immunosuppressed patients, however, sometimes it can also infect immunocompetent individuals. Nocardia infection can disseminate to any organ system of the body but the pulmonary system is the most commonly involved system. In some rare cases, the heart can also be involved and the resulting cardiac mycetoma can be treated successfully with antimicrobials without the need of surgery, unlike fungal cardiac mycetomas wherein surgery may be required in addition to antimicrobial therapy. We present an interesting case of post-renal transplant cardiac nocardiosis, which was treated successfully with a course of antibiotics.

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.

Evaluating the Contribution of Nocardia spp. and Mycobacterium tuberculosis to Pulmonary Infections among HIV and Non-HIV Patients at the Komfo Anokye Teaching Hospital, Ghana

Tuberculosis (TB) is a major cause of human mortality particularly in association with the human immunodeficiency virus (HIV). Nocardia spp. has emerged as an opportunistic infection especially in HIV patients. The high prevalence of TB and HIV coupled with the lack of a definitive laboratory diagnosis for Nocardia spp. could lead to misdiagnosed pulmonary TB. This study determined the prevalence of pulmonary infections due to Nocardia spp. and Mycobacterium tuberculosis in sputum of HIV and non-HIV patients with suspected pulmonary tuberculosis at KATH. A total of sixty sputum samples were obtained from HIV and non-HIV patients with suspected pulmonary tuberculosis. Samples were examined by fluorescence based Ziehl–Neelsen staining, culture, and PCR methods. The prevalence of Nocardia spp. and Mycobacterium tuberculosis was 18.3% and 20%, respectively, with the latter having the highest rate among patients aged 21–40 years (P=0.075). The prevalence of Nocardia spp. among HIV patients was 90.9% whilst 16.7% of the patients had HIV/Nocardia spp. coinfection. Detection of Mycobacterium tuberculosis by fluorescence-based Ziehl–Neelsen staining, culture, and PCR yielded 9 (15%), 11 (18.3%), and 12 (20%), respectively. There is a high prevalence of nocardiosis especially in HIV patients. PCR is a better diagnostic method that detects both Nocardia spp. and Mycobacterium tuberculosis and should be incorporated into routine diagnosis for pulmonary infections.

Manifestations and outcomes of nocardia infections: Comparison of immunocompromised and nonimmunocompromised adult patients

Nocardia is a ubiquitous environmental pathogen that causes infection primarily following inhalation into the lungs. It is generally thought to cause infection primarily in immunocompromised patients, but nonimmunocompromised individuals are also at risk of infection. We sought to compare risk factors, clinical manifestations, diagnostic approach, treatment, and mortality in immunocompromised and nonimmunocompromised adults with nocardiosis.We studied all adults with culture-proven Nocardia infection at a tertiary care hospital from 1994 to 2015 and compared immunocompromised with nonimmunocompromised patients. The immunocompromised group included patients who had a solid organ transplant, hematopoietic cell transplant (HCT), hematological or solid tumor malignancy treated with chemotherapy in the preceding 90 days, inherited immunodeficiency, autoimmune/inflammatory disorders treated with immunosuppressive agents, or high-dose corticosteroid therapy for at least 3 weeks before the diagnosis of nocardiosis.There were 112 patients, mean age 55 ± 17 years; 54 (48%) were women. Sixty-seven (60%) were immunocompromised, and 45 (40%) were nonimmunocompromised. The lung was the site of infection in 54 (81%) immunocompromised and 25 (55%) nonimmunocompromised patients. Pulmonary nocardiosis in immunocompromised patients was associated with high-dose corticosteroids, P = .002 and allogeneic HCT, P = .01, and in nonimmunocompromised patients with cigarette smoking, bronchiectasis, and other chronic lung diseases, P = .002.Cavitation occurred only in the immunocompromised group, P < .001. Disseminated infection was more common in the immunocompromised, P = .01, and was highest in solid organ transplant recipients, P = .007. Eye infection was more common in nonimmunocompromised patients, P = .009. Clinical signs and symptoms did not differ significantly between the 2 groups. The initial treatment for most patients in both groups was trimethoprim-sulfamethoxazole with or without a carbapenem. All-cause 1-year mortality was 19%; 18 (27%) immunocompromised and 3 (7%) nonimmunocompromised patients died, P = .01.Immunocompromised patients with nocardiosis had more severe disease and significantly higher mortality than nonimmunocompromised patients, but clinical presentations did not differ.

Role of FNA and Special Stains in Rapid Cytopathological Diagnosis of Pulmonary Nocardiosis

BACKGROUND

Nocardia, a gram-positive aerobic bacillus of the Actinomycetales family, is a significant opportunistic pathogen in immunocompromised individuals. Clinical and radiological features of pulmonary nocardiosis are nonspecific and can be misdiagnosed as tuberculosis, pneumocystis, staphylococcal or fungal infections, or as malignancy. Aspiration cytology with special stains is a quick and effective approach for accurate diagnosis.

MATERIALS AND METHODS

We present 7 cases of pulmonary nocardiosis, admitted to the pathology department in a tertiary-care hospital in Punjab. Clinical findings, immune status, laboratory tests, chest radiographs, and computed tomography scans were reviewed. Cytologically, special stains like 1% Ziehl-Neelsen (ZN), 20% ZN, periodic acid-Schiff (PAS), Grocott methenamine silver (GMS), and reticulin stains were studied along with May-Grünwald Giemsa, Papanicolaou, and hematoxylin and eosin.

RESULTS

All the patients were immunocompromised. The radiological changes were nonspecific. Cytomorphology showed acute and chronic inflammatory infiltrates with necrosis. None of the cases showed well-defined granulomas. GMS, modified 1% ZN and, Gordon and Sweet reticulin stains highlighted the delicate filamentous bacteria in all cases. PAS and 20% ZN stain for tuberculous bacilli were uniformly negative.

CONCLUSION

FNAC can provide a quick and accurate diagnosis of nocardiosis and thereby facilitate timely medical management.

An Elderly Man With Pancreatic Neuroendocrine Tumor and a Cavitary Right Upper Lobe Lung Mass

CASE PRESENTATION

An elderly man presented to the ED from a nursing care facility after transient loss of consciousness. Three weeks previously, the patient had been diagnosed with a high-grade pancreatic neuroendocrine tumor (NET) with metastases to the liver after being hospitalized for weakness. A chest radiograph at that time had revealed a right upper lobe mass that was presumed to represent a metastatic lesion (Fig 1); CT of the chest demonstrated similar findings (Fig 2). The patient had recovered consciousness on arrival to the ED and was diagnosed clinically as having had a syncopal episode from dehydration due to poor intake. On review of systems, the patient reported shortness of breath and a cough productive of scant mucoid sputum of 1 week's duration. He had no complaints of fever but complained of weakness and poor appetite. In addition, his medical history was significant for hypertension, diabetes mellitus, and congestive heart failure with systolic dysfunction. He was a former smoker. Prior to his recent illness and hospitalization, he lived at home with his family and was independent in his activities of daily living.

Susceptibility profiles of Nocardia spp. to antimicrobial and antituberculotic agents detected by a microplate Alamar Blue assay

Nocardia species are ubiquitous in natural environments and can cause nocardiosis. Trimethoprim-sulfamethoxazole has long been the monotherapy treatment of choice, but resistance to this treatment has recently emerged. In this study, we used microplate Alamar Blue assays to determine the antimicrobial susceptibility patterns of 65 standard Nocardia isolates, including 28 type strains and 20 clinical Nocardia isolates, to 32 antimicrobial agents, including 13 little studied drugs. Susceptibility to the most commonly used drug, trimethoprim-sulfamethoxazole, was observed in 98% of the isolates. Linezolid, meropenem, and amikacin were also highly effective, with 98%, 95%, and 90% susceptibility, respectively, among the isolates. The isolates showed a high percentage of resistance or nonsusceptibility to isoniazid, rifampicin, and ethambutol. For the remaining antimicrobials, resistance was species-specific among isolates and was observed in traditional drug pattern types. In addition, the antimicrobial susceptibility profiles of a variety of rarely encountered standard Nocardia species are reported, as are the results for rarely reported clinical antibiotics. We also provide a timely update of antimicrobial susceptibility patterns that includes three new drug pattern types. The data from this study provide information on antimicrobial activity against specific Nocardia species and yield important clues for the optimization of species-specific Nocardia therapies.

Pulmonary Nocardiosis: A Clinical Analysis of 30 Cases

Objective Pulmonary nocardiosis frequently develops as an opportunistic infection in patients with malignant tumor and is treated with steroids. This study was performed to clarify the clinical features of pulmonary nocardiosis in Japan. Methods The patients definitively diagnosed with pulmonary nocardiosis at our hospital between January 1995 and December 2015 were retrospectively investigated. Results Nineteen men and 11 women (30 in total) were diagnosed with pulmonary nocardiosis. Almost all patients were complicated by a non-pulmonary underlying disease, such as malignant tumor or collagen vascular disease, or pulmonary disease, such as chronic obstructive pulmonary disease or interstitial pneumonia, and 13 patients (43.3%) were treated with steroids or immunosuppressors. Gram staining was performed in 29 patients, and a characteristic Gram-positive rod was detected in 28 patients (96.6%). Thirty-one strains of Nocardia were isolated and identified. Seven strains of Nocardia farcinica were isolated as the most frequent species, followed by Nocardia nova isolated from 6 patients. Seventeen patients died, giving a crude morality rate of 56.7% and a 1-year survival rate of 55.4%. The 1-year survival rates in the groups with and without immunosuppressant agents were 41.7% and 59.7%, respectively, showing that the outcome of those receiving immunosuppressants tended to be poorer than those not receiving them. Conclusion Pulmonary nocardiosis developed as an opportunistic infection in most cases. The outcome was relatively poor, with a 1-year survival rate of 55.4%, and it was particularly poor in patients treated with immunosuppressant agents. Pulmonary nocardiosis should always be considered in patients presenting with an opportunistic respiratory infection, and an early diagnosis requires sample collection and Gram staining.

A 58-Year-Old Female with Progressive Cough and Right Shoulder Pain

Cavitary pneumonia in immunocompromised patients is a challenging entity. Establishing accurate diagnosis and starting effective antibiotics are essential steps towards improving outcome. A 58-year-old stem cell transplant patient was admitted to the hospital with necrotizing pneumonia caused by nocardia. The disease progressed despite of aggrieve antimicrobial therapy. Nocardiosis continues to be a difficult disease to diagnose and treat.

Different faces of Nocardia infection in renal transplant recipients

AIM

Nocardia infections are an uncommon but important cause of morbidity and mortality in renal transplant recipients. The present study was carried out to determine the spectrum of Nocardia infections in a renal transplant centre in Australia.

METHODS

A retrospective chart analysis of all renal transplants performed from 2008 to 2014 was conducted to identify cases of culture proven Nocardia infection. The clinical course for each patient with nocardiosis was examined.

RESULTS

Four of the 543 renal transplants patients developed Nocardia infection within 2 to 13 months post-transplant. All patients were judged at high immunological risk of rejection pre-transplant and had received multiple sessions of plasmaphoeresis and intravenous immunoglobulin before the onset of the infection. Two patients presented with pulmonary nocardiosis and two with cerebral abscesses. One case of pulmonary nocardiosis was complicated by pulmonary aspergillosis and the other by cytomegalovirus pneumonia. All four patients improved with combination antibiotic therapy guided by drug susceptibility testing. At the time of Nocardia infection all four patients were receiving primary prophylaxis with trimethoprim/sulphamethoxazole (TMP/SMX) 160/800 mg, twice weekly.

CONCLUSION

Plasmaphoeresis may be risk factor for Nocardia infection and need further study. Nocardia infection may coexist with other opportunistic infections. Identification of the Nocardia species and drug susceptibility testing is essential in guiding the effective management of patients with Nocardia. Intermittent TMP-SMX (one double strength tablet, twice a week) appears insufficient to prevent Nocardia infection in renal transplant recipients.

[Nocardiosis: A retrospective case series of 19 patients]

INTRODUCTION

Nocardiosis are uncommon. The diagnosis may be difficult, with significant morbidity and mortality, often occurring on frail patients. Few data are available in France.

METHODS

A retrospective single center study was conducted from 2002 to 2014 and included all patients with at least one positive microbiological sample for Nocardia with a follow-up in our hospital.

RESULTS

Nineteen patients, including 15 men, were included with a mean age of 58 years (25-85). Seventeen had a risk factor (lung diseases [13], corticosteroids [12], solid neoplasia [2], HIV infection [2], diabetes mellitus [3], kidney transplant [2], lymphopenia [1]). Infections' locations were: pulmonary (12), brain (3), skin (2), lymph node (1) and corneal (1). The slow growth leads to a median of 35 days for a positive result (3-95). Nine species were identified. Fifteen patients (79%) received one or more lines of antibiotics including: cotrimoxazole (9), amoxicillin (7) cefotaxime/ceftriaxone (7) imipenem (3), or amikacin (3). The average duration of antibiotic therapy was 207 days. Four patients did not receive antibiotics due to a late result or a bacterial co-infection masking nocardiosis. Five patients died (26%) including 2 with cerebral nocardiosis. Six patients were cured, 4 suffered a relapse, 4 had an unknown evolution, and 1 was still treated.

CONCLUSION

Our study shows that nocardiosis is a disease difficult to treat. A better understanding of this type of infection is necessary.

Specific clinical manifestations of Nocardia: A case report and literature review

Nocardiosis is a rare bacterial infection of either the lungs (pulmonary) or body (systemic) that usually affects immunocompromised individuals. It is caused by Gram-positive, aerobic actinomycetes of the Nocardia genus. Multiple high-density sheet shadows in both lungs along with nodules or cavities are the most common presentations of nocardiosis, whereas a large pulmonary mass is considered to be rare. However, there is no specificity in the clinical manifestation of the disease. Therefore, isolation and identification of Nocardia strains is the only reliable diagnostic method. The present study describes the cases of two male patients of Asian descent with nocardiosis. Chest computed tomography scans showed a suspected tumor mass in both patients. Microscopic analysis and culturing of tissue samples obtained using a bronchoscope detected the presence of Nocardia wallacei. Neither patient showed signs of immunosuppression. The present study aimed to improve the understanding of lung nocardiosis and demonstrated that pulmonary nocardiosis should be suspected in the case of non-immunocompromised patients with a large mass in the lung. Furthermore, a review of the literature on infection with Nocardia was conducted.

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.

Pulmonary nocardiosis in Chronic Obstructive Pulmonary Disease: A new clinical challenge

Pulmonary nocardiosis (PN) is a rare but severe disease caused by Nocardia spp. Despite the traditional description as opportunistic infection, case reports and case series of pulmonary nocardiosis have recently been reported in immunocompetent patients too, in particular among people with chronic pulmonary diseases such as advanced Chronic Obstructive Pulmonary Disease (COPD). PN is characterized by non-specific symptoms and radiological findings; bacteriological culture can be difficult. For the reasons above, diagnosis of PN is challenging, sometimes resulting in a misdiagnosis of tuberculosis. We report an interesting case of PN in a 75-year-old male with COPD. He complained a 3-months history of fatigue, evening rise in body temperature, night sweats, unexplained weight loss of 5 kg, worsening dyspnea, cough and mucopurulent sputum. The chest X-ray showed multiple nodules with cavitations bilaterally in the apical and subclavian regions. Nocardia cyriacigeorgica with 100% identity was identified in three sputum samples. Since the patient has never undergone a systemic and/or inhaled steroid therapy, and has no respiratory failure and comorbidities entailing immunodepression, it is conceivable that, in this immunocompetent patient, the COPD could represent an isolated risk factor for PN. Risk factors, clinical presentations, radiographic findings, differential diagnosis and review of the literature of PN cases in COPD, pointing out the similarities and differences, are also described.