Pancytopenia following adjuvant therapy with interferon-gamma in a patient with disseminated nocardiosis

A patient with disseminated nocardiosis developed pancytopenia after treatment with recombinant interferon-gamma (IFN-γ). While no previous clinical reports link pancytopenia to IFN-γ, our observations align with basic research on myelosuppressive effects of IFN-γ. Adjunctive IFN-γ may improve standard nocardiosis therapy, but vigilant monitoring of its hematologic effects is necessary.

[Acute abdomen-Rare cause in an 80-year-old female patient under immunosuppressive treatment]

An 80-year-old woman presented to the emergency department due to abdominal pain. She had a history of opportunistic pneumonia under the effects of immunosuppression after the diagnosis of autoimmune hepatitis. The imaging showed an omental cake formation and the suspicion of peritoneal carcinomatosis. The patient developed an acute abdomen during the hospital stay, followed by exploratory laparotomy. In the presence of extensive intra-abdominal abscess formation both surgically acquired material and blood culture revealed disseminated nocardiosis. The course was fatal due to fulminant septic shock.

Successful maintenance treatment of disseminated nocardiosis with cerebral abscess in a severely immunocompromised patient allergic to trimethoprim-sulfamethoxazole using moxifloxacin and high-dose minocycline: A case report

Nocardiosis in patients after allogeneic hematopoietic stem cell transplantation (HSCT) is rare, but is associated with a significant mortality risk. Although trimethoprim-sulfamethoxazole (TMP/SMX) remains the cornerstone of nocardiosis treatment, optimal alternative therapies for patients intolerant to TMP/SMX are not well-established. Herein, we report a case of disseminated nocardiosis with bacteremia and multiple lesions in the lungs and brain caused by Nocardia farcinica, in a 60-year-old man who had previously undergone allogeneic HSCT and was receiving immunosuppressants for severe chronic graft-versus-host disease. The patient received atovaquone for the prophylaxis of Pneumocystis pneumonia because of a previous serious allergic reaction to TMP/SMX. The patient was initially treated with imipenem/cilastatin and amikacin, which were later switched to ceftriaxone and amikacin based on the results of antimicrobial susceptibility testing. After switching to oral levofloxacin and a standard dose of minocycline, the patient experienced a single recurrence of brain abscesses. However, after switching to oral moxifloxacin and high-dose minocycline, the patient did not experience any relapses during the subsequent two years and seven months of treatment. In treating nocardiosis with brain abscesses, it is crucial to select oral antibiotics based on the antimicrobial susceptibility test results and pharmacokinetics, especially when TMP/SMX is contraindicated. A combination of oral moxifloxacin and high-dose minocycline could be a promising alternative therapy.

Risk factors for Nocardia infection among allogeneic hematopoietic cell transplant recipients: A case-control study of the Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation

OBJECTIVES

Nocardiosis is a rare but life-threatening infection after hematopoietic cell transplantation (HCT). We aimed at identifying risk factors for nocardiosis after allogeneic HCT and clarifying the effect of trimethoprim-sulfamethoxazole prophylaxis on its occurrence.

METHODS

We performed a retrospective multicenter case-control study of patients diagnosed with nocardiosis after allogeneic HCT between January 2000 and December 2018. For each case, two controls were matched by center, transplant date, and age group. Multivariable analysis was conducted using conditional logistic regression to identify potential risk factors for nocardiosis. Kaplan-Meier survival curves of cases and controls were compared using log-rank tests.

RESULTS

Sixty-four cases and 128 controls were included. Nocardiosis occurred at a median of 9 months after allogeneic HCT (interquartile range: 5-18). After adjustment for potential confounders in a multivariable model, Nocardia infection was associated with tacrolimus use (adjusted odds ratio [aOR] 9.9, 95 % confidence interval [95 % CI]: 1.6-62.7), lymphocyte count < 500/µL (aOR 8.9, 95 % CI: 2.3-34.7), male sex (aOR 8.1, 95 % CI: 2.1-31.5), recent use of systemic corticosteroids (aOR 7.9, 95 % CI: 2.2-28.2), and recent CMV infection (aOR 4.3, 95 % CI: 1.2-15.9). Conversely, use of trimethoprim-sulfamethoxazole prophylaxis was associated with a significantly decreased risk of nocardiosis (aOR 0.2, 95 % CI: 0.1-0.8). HCT recipients who developed nocardiosis had a significantly decreased survival, as compared with controls (12-month survival: 58 % and 90 %, respectively; p < 0.0001).

CONCLUSIONS

We identified six factors independently associated with the occurrence of nocardiosis among allogeneic HCT recipients. In particular, trimethoprim-sulfamethoxazole prophylaxis was found to protect against nocardiosis.

Gastrointestinal dysbiosis induced by Nocardia sp. infection in tilapia

Nocardiosis has caused high mortalities among fish cultures; however, the effects of Nocardia infections in the fish gastrointestinal microbiota are unknown. In this research, tilapia was infected with Nocardia sp., to analyze the effect of infection on the gastrointestinal microbiota. Tilapia infected with Nocardia sp. reported a 46 % survival (100 % in non-infected). Moreover, the infection caused severe damage to the stomach microbiota, with a loss of diversity and a significant increase of Proteobacteria (94.8 %), resulting in a negative correlation network between Proteobacteria and other important phyla. Nocardia sp. is an emerging pathogen capable of inducing dysbiosis and causing significant mortalities.

Disseminated nocardiosis and anti-GM-CSF antibodies

Infections that are unusually severe or caused by opportunistic pathogens are a hallmark of primary immunodeficiency (PID). Anti-cytokine autoantibodies (ACA) are an emerging cause of acquired immunodeficiency mimicking PID. Nocardia spp. are Gram-positive bacteria generally inducing disseminated infections in immunocompromised patients, but seldom also occurring in apparently immunocompetent hosts. Anti-GM-CSF autoantibodies are associated with autoimmune pulmonary alveolar proteinosis (PAP). In those patients, an increased incidence of disseminated nocardiosis and cryptococcosis has been observed. It is unclear whether the PAP or the autoantibodies predispose to the infection. We report an apparently immunocompetent woman presenting with disseminated nocardiosis without any evidence of PAP. Clinical data and radiological images were retrospectively collected. Lymphocyte populations were analyzed by flow cytometry. Anti-GM-CSF autoantibodies were measured by ELISA. A 55-year-old otherwise healthy woman presented with cerebral and pulmonary abscesses. Personal and familial history of infections or autoimmunity were negative. After extensive examinations, a final diagnosis of disseminated nocardiosis was made. Immunologic investigations including neutrophilic function and IFN-γ/IL-12 circuitry failed to identify a PID. Whole-exome sequencing did not find pathogenic variants associated with immunodeficiency. Serum anti-GM-CSF autoantibodies were positive. There were no clinical or instrumental signs of PAP. Trimethoprim-sulfamethoxazole and imipenem were administered, with progressive improvement and recovery of the infectious complication. We identified anti-GM-CSF autoantibodies as the cause of disseminated nocardiosis in a previously healthy and apparently immunocompetent adult. This case emphasizes the importance of including ACA in the differential diagnosis of PID, especially in previously healthy adults. Importantly, anti-GM-CSF autoantibodies can present with disseminated nocardiosis without PAP.

Disseminated Nocardia nova in a child with relapsed acute lymphoblastic leukemia: a case report

BACKGROUND

Nocardiosis is a rare infection that typically results from inhalation of or inoculation with Nocardia organisms. It may cause invasive disease in immunocompromised patients. This case describes nocardiosis with bacteremia and pulmonary involvement in a child with a hematologic malignancy.

CASE PRESENTATION

A boy with testicular relapsed acute lymphoblastic leukemia with marrow involvement presented with sudden onset of fever, body aches, headaches, chills, and moderate respiratory distress during continuation 2 chemotherapy. Radiographic imaging demonstrated consolidation and ground glass opacities in bilateral lower lungs. Central line blood cultures grew Nocardia nova complex, prompting removal of the central line and initiation of triple therapy with imipenem-cilastatin, linezolid, and trimethoprim-sulfamethoxazole with rapid improvement of symptoms. Antibiotic susceptibilities showed a multidrug-susceptible isolate. The patient is anticipated to remain on trimethoprim-sulfamethoxazole for at least 12 months.

CONCLUSIONS

In an immunocompromised child, blood cultures, chest imaging, and head imaging can aid in the diagnosis of disseminated nocardiosis. Long-term antibiotic therapy is necessary, guided by the organism and simplified with the results of antimicrobial susceptibility testing.

Trimethoprim-sulfamethoxazole significantly reduces the risk of nocardiosis in solid organ transplant recipients: systematic review and individual patient data meta-analysis

BACKGROUND

Whether trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis prevents nocardiosis in solid organ transplant (SOT) recipients is controversial.

OBJECTIVES

To assess the effect of TMP-SMX in the prevention of nocardiosis after SOT, its dose-response relationship, its effect on preventing disseminated nocardiosis, and the risk of TMP-SMX resistance in case of breakthrough infection.

METHODS

A systematic review and individual patient data meta-analysis.

DATA SOURCES

MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Web of Science Core Collection, and Scopus up to 19 September 2023.

STUDY ELIGIBILITY CRITERIA

(a) Risk of nocardiosis between SOT recipients with and without TMP-SMX prophylaxis, or (b) sufficient details to determine the rate of TMP-SMX resistance in breakthrough nocardiosis.

PARTICIPANTS

SOT recipients.

INTERVENTION

TMP-SMX prophylaxis versus no prophylaxis.

ASSESSMENT OF RISK OF BIAS

Risk Of Bias In Non-randomized Studies-of Exposure (ROBINS-E) for comparative studies; dedicated tool for non-comparative studies.

METHODS OF DATA SYNTHESIS

For our primary outcome (i.e. to determine the effect of TMP-SMX on the risk of nocardiosis), a one-step mixed-effects regression model was used to estimate the association between the outcome and the exposure. Univariate and multivariable unconditional regression models were used to adjust for the potential confounding effects. Certainty of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Individual data from three case-control studies were obtained (260 SOT recipients with nocardiosis and 519 uninfected controls). TMP-SMX prophylaxis was independently associated with a significantly decreased risk of nocardiosis (adjusted OR = 0.3, 95% CI 0.18-0.52, moderate certainty of evidence). Variables independently associated with an increased risk of nocardiosis were older age, current use of corticosteroids, high calcineurin inhibitor concentration, recent acute rejection, lower lymphocyte count, and heart transplant. Breakthrough infections (66/260, 25%) were generally susceptible to TMP-SMX (pooled proportion 98%, 95% CI 92-100).

CONCLUSIONS

In SOT recipients, TMP-SMX prophylaxis likely reduces the risk of nocardiosis. Resistance appears uncommon in case of breakthrough infection.

Multiple brain abscesses caused by Nocardia asiatica: Case report and literature review

Nocardia are opportunistic pathogens mainly affecting immunocompromised individuals. Nocardia asiatica, a novel species, can cause severe infections. We present a case of multiple brain abscesses due to Nocardia asiatica, discussing its diagnosis and treatment. In January 2022, a 27-year-old Chinese woman with a history of atypical membranous nephropathy presented with low-grade fever, cough, limb weakness, and headaches. Imaging revealed lung and brain lesions. Neurological symptoms worsened over time, culminating in recurrent seizures and severe headaches. A brain MRI confirmed multiple abscesses. Craniotomy and lesion removal were performed, leading to a diagnosis of brain abscesses caused by Nocardia asiatica. Empirical antibiotics were followed by targeted regimen. After successful treatment, the patient remained symptom-free during follow-ups. Nocardia asiatica multiple brain abscesses are exceedingly rare. This case underscores the importance of considering nocardiosis in immunosuppressed patients presenting with neurological symptoms. Timely neurosurgical intervention and effective antibiotic therapy are crucial. Metagenomic next-generation sequencing proved invaluable for rapid diagnosis. Treatment with trimethoprim-sulfamethoxazole (TMP-SMX) and a carbapenem followed by TMP-SMX alone achieved disease control. This case contributes to the understanding of Nocardia asiatica infections and highlights the role of neurosurgical procedures in managing disseminated nocardiosis.

Pleural effusion-related Nocardia otitidiscaviarum, Anaplasma platys and Ehrlichia canis coinfection in a dog

The coinfections by some microorganisms have been related to severe diseases in humans and animals, where immunosuppressive agents favor opportunistic behavior of other pathogens. A 4-month-old, female mixed-breed dog with a two-week history of inappetence, prostration, emaciation, and respiratory distress was admitted at a veterinary hospital in Brazil. Tachycardia, pale mucous membranes, severe respiratory distress, and a large number of ticks (Rhipicephalus sanguineus s.l.) in different body regions were observed at clinical examination. Hematological examination of dog showed leukocytosis, neutrophilia, mild anemia, and thrombocytopenia, whereas unremarkable values in biochemical tests. Thoracic radiography revealed a pleural effusion image. Blood and the pleural fluid (purulent aspect) samples were subjected to qPCR (16S rRNA and dsb genes) and sequencing, which identified Ehrlichia canis and Anaplasma platys coinfection. An aggregate of coccoid-to-branching or long filamentous microorganisms, surrounded by pyogranulomatous inflammatory reaction was seen at the cytology of the pleural fluid. Bacteriological culture of pleural effusion showed colonies compatible with the genus Nocardia, which revealed gram-positive filamentous organisms with a tendency of fragmentation and were identified as Nocardia otitidiscaviarum in mass spectrometry (MALDI-TOF MS). Therapy of N. otitidiscaviarum isolate using levofloxacin (supported by a previous in vitro susceptibility testing) and doxycycline for E. canis and A. platys resulted in complete resolution of the clinical picture. Here, we report for the first time a triple coinfection by Nocardia otitidiscaviarum, A. platys, and E. canis in a dog with pleural effusion, where debilitating or immunosuppressive conditions induced by A. platys and E. canis coinfection probably contributed to the opportunistic behavior of N. otitidiscaviarum.

Nocardiosis: a single-center experience and literature review

INTRODUCTION

Nocardiosis is a rare bacterial infection caused by Nocardia spp. However, an increasing incidence has been described whereby data about epidemiology and prognosis are essential.

METHODS

A retrospective descriptive study was conducted among patients with positive Nocardia spp. culture, from January 2019 to January 2023, at a Terciary Hospital in Portugal.

RESULTS

Nocardiosis was considered in 18 cases with a median age of 63.8-years-old. At least one immunosuppressive cause was identified in 70% of patients. Five patients had Disseminated Nocardiosis (DN). The lung was the most common site of clinical disease (77.8%) and Nocardia was most commonly identified in respiratory tract samples. The most frequently isolated species were Nocardia nova/africana (n = 7) followed by Nocardia cyriacigeorgica (n = 3) and Nocardia pseudobrasiliensis (n = 3). The majority of the patients (94.4%) received antibiotic therapy, of whom as many as 55.6% were treated with monotherapy. The most frequently prescribed antibiotic was trimethoprim-sulfamethoxazole. Selected antimicrobial agents were generally effective, with linezolid and cotrimoxazole (100% Susceptibility [S]) and amikacin (94% S) having the most activity against Nocardia species. The median (IQR) duration of treatment was 24.2 (1‒51.4) weeks for DN; The overall one-year case fatality was 33.3% (n = 6) and was higher in the DN (66.7%). No recurrence was observed.

CONCLUSION

Nocardiosis is an emerging infectious disease with a poor prognosis, particularly in DN. This review offers essential epidemiological insights and underscores the importance of gaining a better understanding of the microbiology of nocardiosis. Such knowledge can lead to the optimization of antimicrobial therapy and, when necessary, guide appropriate surgical interventions to prevent unfavorable outcomes.

Evaluation of BACTEC MGIT 960 system for recovery of Nocardia from clinical specimens

Nocardia spp. is an aerobic Gram-positive bacillus responsible for nocardiosis. Herein, we performed a retrospective study to evaluate the performance of BACTEC MGIT 960 system, in comparison with smear microscopy and blood agar plate (BAP) culture, to recover Nocardia from different clinical specimens. Furthermore, the inhibitory effect of antibiotics contained in MGIT 960 tube on Nocardia was also evaluated. The sensitivities for Nocardia recovery using smear microscopy, BAP culture, and MGIT 960 were 39.4% (54/137), 46.1% (99/215), and 81.3% (156/192), respectively. N. farcinica was the most detected species (60.4%, 136/225). In MGIT 960-recovered Nocardia strains, N. farcinica accounted for 76.9%. Furthermore, trimethoprim in MGIT 960 tube inhibited less N. farcinica growth than that of other Nocardia species, partially explaining why MGIT 960 recovered more N. farcinica from sputa. The current study demonstrated that MGIT 960 could recover Nocardia strains from heavily-contaminated samples if its components and antibiotics are redesigned.

Molecular detection of Nocardia: development and application of a real-time PCR assay in sputum and bronchoalveolar lavage fluid samples

The diagnosis of pulmonary nocardiosis remains challenging. Rapid detection of Nocardia is of primary importance for early diagnosis and precise treatment of nocardiosis. In this study, our objective was to develop and validate a new TaqMan real-time PCR (qPCR) assay for rapidly detecting Nocardia spp. in respiratory samples. Based on published sequence data, primers in a conserved region of the 16S rRNA gene and a probe within that region that was specific for Nocardia were designed. The distinction effect of the qPCR assay was assessed between Nocardia and other respiratory-associated bacteria. Furthermore, the specificity and sensitivity of the assay were evaluated in respiratory clinical samples (n = 205), compared to the results of 16S rRNA gene amplicon sequencing and clinical diagnosis. The qPCR assay exhibited high specificity, sensitivity, repeatability, and reproducibility. The limit of detection of standard plasmid DNA was 3 × 10² copies/mL. Additionally, the qPCR assay was applied to the direct detection of 205 clinical respiratory samples. The specificity and sensitivity of the qPCR were all 100% compared to 16S rRNA gene amplicon sequencing, as well as 98.4% and 100% compared to clinical diagnosis respectively. The qPCR yielded results within 3 h of sample processing, compared to several days for culture, significantly reducing turnaround time. The results suggest that the new qPCR assay developed in this study provides reliable and rapid detection of Nocardia spp. in the respiratory tracts and is expected to reduce the time required for diagnosing and treating nocardiosis.

Several Nocardia abcessus bronchiolitis in a patient treated with inhaled corticosteroids: a case report

Nocardiosis is a disease that mainly affects immunocompromised patients. Inhaled corticosteroids (ICS) are standard of care for asthma. This treatment can induce respiratory infections but no case of bronchiolitis nocardiosis have been described so far. A 58-year-old man, with history of controlled moderate allergic asthma, develop an increased cought in the last two years associated with dyspnea on exertion. Within two months, although ICS were increased to high doses, symptoms worsened due to a severe obstructive ventilatory disorder as revealed by pulmonary function tests (PFT). Small-scale lesions (< 10%) were found on chest computed tomography (CT). A bronchoalveolar lavage (BAL) found Nocardia abcessus. After six months of Sulfamethoxazole/Trimethoprim, PFT results improved and chest CT became completely normal. We therefore present the case of a bronchiolitis nocardiosis with several bronchial syndrome and the only immunosuppressive factor found were ICS.

Clinical manifestations and outcome of nocardiosis and antimicrobial susceptibility of Nocardia species in southern Taiwan, 2011-2021

BACKGROUND/PURPOSE

Nocardiosis is an uncommon infectious disease. This study aimed to assess the clinical outcome of patients with nocardiosis and examine the antimicrobial susceptibility profiles of Nocardia spp. isolated.

METHODS

We retrospectively reviewed the medical records of all inpatients diagnosed with nocardiosis between 2011 and 2021. The identification of Nocardia spp. at the species level was performed with the use of MALDI-TOF and 16S rRNA assays. The antimicrobial susceptibility of Nocardia spp. was performed using the microbroth dilution method. Factors associated with 90-day all-cause mortality were identified in multivariate logistic regression analysis.

RESULTS

Of 60 patients with nocardiosis in the 11-year study period, the lungs (55.0%) were the most common site of involvement, followed by the skin and soft tissue (45.0%). Twenty-two patients (36.7%) died within 90 days following the diagnosis. All of the Nocardia isolates were susceptible to trimethoprim-sulfamethoxazole, linezolid, and amikacin, whereas more than 70% of the isolates were not susceptible to ciprofloxacin, imipenem-cilastatin, moxifloxacin, cefepime, and clarithromycin. Nocardiosis involving the lungs (relative risk [RR], 9.99; 95% confidence interval [CI], 1.52-65.50; p = 0.02), nocardiosis involving the skin and soft tissue (RR, 0.15; 95% CI, 0.02-0.92; p = 0.04), and treatment with trimethoprim-sulfamethoxazole (RR, 0.14; 95% CI, 0.03-0.67; p = 0.01) were independently associated with 90-day all-cause mortality.

CONCLUSIONS

Nocardia spp. identified between 2011 and 2021 remained fully susceptible to trimethoprim-sulfamethoxazole, linezolid, and amikacin. Nocardiosis of the lungs, skin and soft tissue infection, and treatment with trimethoprim-sulfamethoxazole were independently associated with 90-day all-cause mortality.

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.

Clinical characteristics, susceptibility profiles, and treatment of nocardiosis: A multicenter retrospective study in 2015-2021

OBJECTIVES

This study aimed to investigate microbiological characteristics, antimicrobial resistance profiles, antibiotic choice, and outcomes of Nocardia infection in various centers over a 7-year period (from 2015 to 2021).

METHODS

We retrospectively analyzed the medical records of all hospitalized patients diagnosed with Nocardia between 2015 and 2021.The isolates were identified to the species level via the sequencing of 16S rRNA, secA1 or ropB genes. The susceptibility profiles were determined using the broth microdilution method.

RESULTS

Out of the 130 cases nocardiosis, 99 (76.2%) were established as pulmonary infection, of which the most common underlying disease was chronic lung disease (40.4%,40/99), including bronchiectasis, chronic obstructive pulmonary disease(COPD), and chronic bronchitis. Among 130 isolates, 12 species were identified, with the most common species being N. cyriacigeorgica (37.7%) and N. farcinica (20.8%). All Nocardia strains were susceptible to linezolid and amikacin, and the susceptibility rate of trimethoprim-sulfamethoxazole (TMP-SMX) was 97.7%. Of the 130 patients, 86 (66.2%) received TMP-SMX monotherapy or multidrug regimen. Further, 92.3% patients who were treated achieved clinical improvement.

CONCLUSIONS

TMP-SMX was the treatment of choice for nocardiosis, and other combination drugs with TMP-SMX therapy yielded even better results.

A multi-centre retrospective study of Nocardia speciation and antimicrobial susceptibility in Queensland, Australia

The study aims to characterise the species identification and antimicrobial susceptibility testing (AST) results of Nocardial isolates from adult patients across major public hospitals in Queensland, Australia, over a 15-year period. A multi-centre retrospective observational study of Nocardia sp. isolates was conducted from 7 major public hospitals in Queensland, Australia, over a 15-year period. Clinical samples from patients aged ≥ 18 years that isolated Nocardia sp. were included. Demographic and clinical data were collected, along with species identification and AST results. Overall, 484 Nocardia sp. were isolated. Most patients were male (297, 61%) with a mean (IQR) age of 60 (51-75) and a median (IQR) Charlson Comorbidity Index of 4 (2-6). Of these, 239 (49%) patients were immunosuppressed. Organisms were most frequently isolated from sputum (174, 36%), and superficial swabs (102, 21%). Patients presented with pulmonary infections (165, 35%) and superficial skin and soft tissue infections (87, 18%) most commonly. One hundred (21%) isolates were deemed pulmonary colonisation and were not treated. Of the speciated organisms, N. nova complex was the most common (93, 19%), followed by N. farcinica complex (79, 16%). Organisms were reliably susceptible to linezolid (240/245, 98%), amikacin (455/470, 97%), and trimethoprim/sulfamethoxazole (459/476, 96%), but less so to imipenem (243/472, 51%) and ceftriaxone (261/448, 58%). This is the largest Australian description of Nocardia sp. to date. Given antimicrobials are often commenced prior to AST results and sometimes even speciation, characterisation of local species and antibiogram data is important to guide empiric choices and local guidelines.

Ulceration by Nocardia Otitidiscaviarum: A case study

Nocardiosis is an acute, subacute or chronic infectious disease that occurs in cutaneous, pulmonary and disseminated forms. We present a case of Nocardiosis in a post-COVID-19 patient with cutaneous ulceration due to Nocardia otitidiscaviarum, managed with cotrimoxazole and linezolid. Early diagnosis and management proved crucial in preventing dissemination of the organism and improving the patient's outcome.

Nocardia infections in Italy: from a local to a national view

In this paper, we have described cases of nocardiosis that occurred in our hospital and examined the literature on other nocardiosis cases recorded in Italy. We have collected the clinical details of our recent cases and described them in full. Regarding the older cases in our hospital and the Italian cases present in the literature, we noted the clinical data, the Nocardia species involved, and the antimicrobial susceptibility reported. The survey was carried out on PubMed. The first of our cases is an elderly woman with compromised health who had a lung and bloodstream infection. A second case is a middle-aged man who developed an infection in the thigh. A third patient is a middle-aged man on immunosuppressive therapy who developed a cerebral abscess. Our review shows that patients are usually immunocompromised, with an average age of 60 years, and more frequently males. The most affected organs are the lungs and the brain, and the most reported species is Nocardia farcinica. Antimicrobial susceptibility tests show good efficacy of linezolid, cotrimoxazole and amikacin. We conclude that, if a Nocardia infection is suspected, the most likely species to be considered in Italy is N. farcinica. In addition, if empirical therapy is needed, we suggest relying on linezolid, cotrimoxazole or amikacin.

The Clinical Characteristic and Management of Patients with Nocardiosis in a Tertiary Hospital in China

Nocardiosis is an uncommon opportunistic bacterial infection which becomes a significant health problem due to its increasing incidence and high mortality rate. However, many nocardiosis patients are underdiagnosed by physicians. To summarize the clinical characteristics and management of nocardiosis would help with better diagnosis and prognosis of nocardiosis. This retrospective study was conducted based on the medical records of nocardiosis patients between January 2015 and December 2021 in a tertiary hospital in China. Overall, 44 nocardiosis patients with 54 specimens were included. The patients consisted of 26 males and 18 females with a mean age of 50.4 ± 13.2 years. Among 44 patients, 26 (59.1%) were previously given immunosuppressive therapy. Connective tissue diseases (CTDs) were the most common underlying disease (16/44). The most frequent infection sites were the lungs (17/44) and skin or soft tissues (8/44). Common symptoms included cough (23/44), expectoration (18/44), fever (15/44), and subcutaneous abscesses (15/44). Forty-five out of 54 specimens (83.3%) required over 48 hours of culture time for nocardiosis detection. Thirty-six patients were cured or improved, 5 patients were discharged from the hospital due to poor prognosis, and 1 patient died. The average diagnosis time of poor prognosis cases was 19.7 days, which was significantly longer than those of improved or cured patients (7.3 days). Immunosuppressed patients comprise a large part of nocardiosis cases, which is worth attention in clinical practice. Early diagnosis, specifically through prolonged cultivation time of specimen, could help achieve better prognosis of nocardiosis patients.

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.

Septic arthritis by Nocardia farcinica: Case report and literature review

Nocardiosis is a bacterial infection caused by organisms of the Nocardia genus. The disease typically involves the skin, central nervous system or pulmonary system. Very rarely nocardiosis can cause disease of other organs including bone and joints. Nocardiosis is typically a chronic, somewhat indolent infection, occurring in patients with defective cell mediated immunity. We describe a 78-year-old female with right shoulder septic arthritis resulting from Nocardia farcinica with associated involvement of her skin and lungs as well. She was treated with surgical debridement and combination antibiotic therapy. We also share a literature review of bone and joint infection caused by the N. farcinica species, highlighting its rarity. Understanding uncommon manifestations of nocardiosis allows for early recognition and treatment of the condition and optimal patient care.

Pulmonary nocardiosis: Risk factors and species distribution from a high burden centre

Nocardiosis is a clinical and diagnostic challenge. This was a retrospective study carried out on cases of pulmonary nocardiosis presenting over 15 years. Clinical data was retrieved using the electronic patient records. Vitek MS 3.2 (MALDI TOF MS) was carried out on 22 isolates and sequencing on another 9 isolates. Of 71 patients presenting with pulmonary nocardiosis, 58 (81.6%) were on immunosuppressant therapy, 26 (46%) had a previous lung pathology, 11 (8%) were HIV associated. Disseminated disease was seen in 6 (8.4%). There were 8 (11.26%) deaths in this cohort of patients. Of 31/71 identified to species, the most common were Nocardia cyriacigeorgica (n ​= ​11) followed by Nocardia farcinica (n ​= ​9).

A fatal case of disseminated nocardiosis due to Nocardia otitidiscaviarum resistant to trimethoprim-sulfamethoxazole: case report and literature review

Background

Disseminated nocardiosis still causes significant morbidity and mortality and is often caused by Nocardia asteroides, N. basiliensis, and N. farcinica and are often treated with trimethoprim–sulfamethoxazole (TMP–SMX). Nocardia otitidiscaviarum (N. otitidiscaviarum) rarely causes disseminated disease and resistance to TMP–SMX is even more rare.

Case presentation

A 37-year-old woman with metastatic breast cancer and right ear deafness with recent occupational gardening and manipulating soil, presented to the hospital with first time seizure and multiple skin nodules. Magnetic resonance imaging (MRI) showed ring enhancing lesions, biopsy of the skin and brain lesions grew N. otitidiscaviarum. She was empirically treated with TMP–SMX and Imipenem–Cilastatin, however, almost three weeks into therapy, susceptibility results revealed it to be resistant to both antimicrobials, she was subsequently changed to Amikacin, Linezolid, Moxifloxacin, and Doxycycline but ultimately died.

Conclusions

This case report highlights the importance of suspecting a rare Nocardia species in patients at risk with proper occupational exposure, moreover, TMP–SMX resistance should be suspected with lack of clinical response, this may have important implications on clinical practice when facing similar infections.

Cerebral nocardiosis in a patient treated with pembrolizumab: a first case report

Background

Checkpoints inhibitors (CPIs) are increasingly used for the treatment of several malignancies. The most common side effects are Immune Related Adverse Events, while infectious complications are rare, especially cerebral nocardiosis.

Case presentation

Here, we report the first clinical case of a cerebral nocardiosis revealed after seizure in a patient treated by pembrolizumab for a metastatic lung cancer, in the absence of any additional immunosuppressive therapy or risk factors for cerebral nocardiosis. The extended evaluation including a brain CT-scan did not reveal any lesion before pembrolizumab. Nevertheless, the 3-month delay between the start of Pembrolizumab and the diagnosis of cerebral nocardiosis suggests that the infection occurred prior to the CPI. Unfortunately, the patient died during treatment for cerebral nocardiosis, while the lung cancer tumor mass had decreased by 80% after the sixth cycle of pembrolizumab.

Conclusions

This case report emphasizes that clinicians should consider diagnoses other than metastasis in a patient with a brain mass and metastatic cancer treated with CPI, such as opportunistic infections or IRAE.

A case report of Nocardia asiatica constrictive pericarditis in a patient with Human Immunodeficiency Virus

Nocardiosis commonly affects the respiratory system and is a rare cause of purulent pericarditis. Invasive nocardial infections occur more frequently in patients with immunosuppression. A misdiagnosis as tuberculosis infection is not uncommon, especially in the context of immunosuppression in high burden tuberculosis settings. The risk factors and clinical features of the two disease entities overlap substantially. Misdiagnosis may lead to a delay in appropriate treatment and may result in poor outcomes. It is important to note that these conditions may also co-exist in the same patient. We describe, to the best of our knowledge, the first case of Nocardia asiatica pericarditis in a 32-year-old man with Human Immunodeficiency Virus infection. The patient was initially diagnosed in September 2020 with a lower respiratory tract infection and pulmonary tuberculosis was suspected. A chest radiograph, performed at admission, revealed a pericardial effusion and N. asiatica was cultured from a pericardial fluid specimen that was collected 5 days following admission. Despite a good initial clinical response to a combination of trimethoprim/sulfamethoxazole and imipenem/cilastatin, the patient demised after 16 weeks of treatment. Previous reports of laboratory confirmed nocardial pericarditis are also reviewed and summarized.

Nocardiosis and elevated beta-d-glucan in solid organ transplant recipients

Beta-D-glucan (BDG) testing can expedite the diagnosis of invasive fungal infections in immunocompromised hosts. Elevated BDG levels have been reported in both in-vitro studies assessing cross-reactivity with Nocardia spp. and published cases of patients with nocardiosis, but there is little data on this association in solid organ transplantation (SOT) recipients. To explore this association, we conducted a case series of SOT recipients with culture-proven nocardiosis and BDG testing who received their care at our institution between 2016 and 2021. We found thirteen cases of nocardiosis in SOT recipients, of which three cases met our case definition of an elevated BDG. Their clinical courses are detailed in the present report. We found that BDG may be elevated in SOT with nocardiosis with no identified cause of false positive BDG, though a causal association cannot be determined. Future prospective studies that better evaluate the association between nocardiosis and BDG are warranted, as are studies that better characterize the possible variability in reactivity amongst Nocardia spp.

Nocardia infections in hematopoietic cell transplant recipients: a multicenter international retrospective study of the Infectious Diseases Working Party (IDWP) of the European Society for Blood and Marrow Transplantation (EBMT)

BACKGROUND

Nocardiosis is rare after hematopoietic cell transplantation (HCT). Little is known regarding its presentation, management, and outcome in this population.

METHODS

In this retrospective international study, we reviewed nocardiosis episodes in HCT recipients (01.01.2000-31.12.2018; 135 transplant centers; 33 countries) and described their clinical, microbiological, radiological, and outcome characteristics.

RESULTS

We identified 81 nocardiosis episodes in 74 allo- and 7 auto-HCT recipients. Nocardiosis occurred at a median of 8 (IQR 4-18) months post-HCT. The most frequently involved organs were lungs (70/81; 86%) and brain (30/81; 37%); 29 (36%) patients were afebrile; 46/81 (57%) had disseminated infections. The most common lung imaging findings were consolidations (33/68; 49%) or nodules (32/68; 47%); and brain imaging findings were multiple brain abscesses (19/30; 63%). 10/30 (33%) patients with brain involvement lacked neurological symptoms. 14/48 (29%) patients were bacteremic. N. farcinica was the most common among molecularly identified species (27%, 12/44). Highest susceptibility rates were reported to linezolid 45/45 (100%), amikacin 56/57 (98%), trimethoprim-sulfamethoxazole 57/63 (90%), and imipenem 49/57 (86%).One-year and last follow-up (IQR: 4-42.5 months) all-cause mortality were 40% (32/81) and 52% (42/81), respectively. In the multivariable analysis, underlying disease not in complete remission (HR 2.81, 95%CI 1.32-5.95), and prior bacterial infection (HR 3.42, 95%CI 1.62-7.22) were associated with higher one-year all-cause mortality.

CONCLUSIONS

Nocardiosis is a late post-HCT infection usually manifesting as a pulmonary disease with frequent dissemination, brain infection and bacteremia. Brain imaging should be performed in HCT recipients with nocardiosis regardless of neurological symptoms. Overall mortality is high.

Nocardiosis with diffuse involvement of the pleura: A case report

BACKGROUND

Nocardiosis is an uncommon infection that usually occurs in immunocompromised patients, and the pulmonary system is the most common site. We report an uncommon case of nocardiosis with diffuse involvement of the pleura, which presented as multiple localized nodular or hillock lesions on computed tomography (CT) with local chest wall infiltration.

CASE SUMMARY

A 54-year-old woman was referred to our hospital due to cough and fever for 20 d. She had a history of nephrotic syndrome for 7 mo and was given prednisone (60 mg/d) 6 mo previously. The hormone was then gradually reduced to the current dose of 25 mg/d. Chest CT showed many nodular or hillock lesions in the right pleura, mediastinum, and interlobar fissure areas. On the lower layer, one lesion infiltrated the chest wall. She was treated with piperacillin sodium and sulbactam sodium, but the therapeutic effect was not good. In this regard, ultrasound-guided local infiltration anesthesia was further conducted for perihepatic hydrops drainage to improve diagnostic accuracy. Puncture fluid culture isolated Nocardia species, confirming the diagnosis of nocardiosis. Subtype Nocardia farcinica was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antibiotic treatment was switched to trimethoprim/sulfamethoxazole and imipenem. After 8 d of treatment, the patient was discharged from the hospital with improved condition, and she has been recurrence-free for 2 years.

CONCLUSION

This report illustrates that nocardiosis should be suspected when clinicians encounter patients who are immunocompromised and have diffuse involvement of the pleura.

Cerebral nocardiosis with osteomyelitis of skull vault complicating a primary neck lesion in an immunocompetent patient: a case report

Nocardia infection is an uncommon and rare condition in immunocompetent patient. A case of cutaneous nocardiosis complicated with osteomyelitis of the vault scalp in a 64-year-old man, with no remarkable past medical history, is reported. Treatment with trimethoprime-sulfamethoxazole than doxycycline for 12 months led to complete resolution and no evidence of recurrence was noted. Nocardia infection should be considered even in immunocomptent patients and doxycycline is a good alternative for treatment.

Rare isolation of Nocardia farcinica in a fatal case of disseminated nocardiosis in an immunocompetent person

Nocardia species can cause various types of infections including, pulmonary, cutaneous, disseminated & CNS diseases. Here, we report a case of disseminated nocardiosis, probably secondary to pulmonary foci, in an immunocompetent patient. Blood culture showed gram-positive bacilli, which on culture grew aerial chalky white growth showed the acid-fast, gram-positive filamentous bacteria. The culture was identified as Nocardia farcinica by MALDI-TOF. Unfortunately, the patient succumbed to the infection on the 5th day after admission.

Pulmonary alveolar proteinosis complicated with nocardiosis: A case report and review of the literature

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a pulmonary syndrome wherein large volumes of phospholipid and protein-rich surfactants accumulate within the alveoli. PAP forms include primary (auto-immune PAP), secondary, and congenital. Nocardiosis is a form of suppurative disease induced upon infection with bacteria of the Nocardia genus. Clinically, cases of PAP complicated with Nocardia infections are rare, regardless of form. Unfortunately, as such, they are easily overlooked or misdiagnosed. We describe, here, the case of a patient suffering from simultaneous primary PAP and nocardiosis.

CASE SUMMARY

A 45-year-old Chinese man, without history of relevant disease, was admitted to our hospital on August 8, 2018 to address complaints of activity-related respiratory exertion and cough lasting over 6 mo. Lung computed tomography (CT) revealed diffuse bilateral lung infiltration with local consolidation in the middle right lung lobe. Subsequent transbronchial lung biopsy and CT-guided lung biopsy led to a diagnosis of primary PAP (granulocyte-macrophage colony-stimulating factor antibody-positive) complicated with nocardiosis (periodic acid-Schiff-positive). After a 6 mo course of anti-infective treatment (sul-famethoxazole), the lesion was completely absorbed, such that only fibrous foci remained, and the patient exhibited significant symptom improvement. Follow-up also showed improvement in pulmonary function and the CT imaging findings of PAP. No whole-lung lavage has been conducted to date. This case highlights that active anti-nocardia treatment may effectively improve the symptoms and alleviate PAP in patients with PAP and nocardia, possibly reducing the need for whole-lung lavage.

CONCLUSION

When evaluating patients presenting with PAP and pulmonary infections, the potential for nocardiosis should be considered.

Disseminated nocardiosis due to Nocardia terpenica

We report the first case of disseminated nocardiosis due to trimethoprim/sulfamethoxazole-resistant Nocardia terpenica successfully treated with meropenem and clarithromycin. The patient travelled to Japan from Australia via Southeast Asia, which led to differential diagnoses of multiple lung nodules including miliary tuberculosis and melioidosis as well as nocardiosis. Because of variety of susceptibility depending on the Nocardia species, clinicians need to confirm the species and investigate its susceptibility.

Pulmonary Nocardiosis in Pemphigus Vulgaris Patients from Tehran, Iran

OBJECTIVE

Nocardiosis is an opportunistic infection in individuals who had organ transplants and in patients with immunosuppressive diseases such as pemphigus Vulgaris (PV), diabetes mellitus, and HIV. Nocardiosis rate has not been assessed in Iranian PV patients, and this was the first study to estimate nocardiosis rate in these patients.

METHODS

In this study, 103 patients with PV were examined. BAL samples were obtained and direct smear was prepared and visualized by microscopy after PAS staining. Samples were cultured on antibiotic-containing blood and chocolate agar media. DNA extraction and PCR were performed on positive cultures, and final identification was done by 16S rRNA gene sequencing. Drug susceptibility testing was done by microbroth dilution method.

RESULTS

Four positive cultures (3.88%) were found in the samples (n = 103). According to sequence analysis, 2 isolates were identified as Nocardia cyriacigeorgica and 2 as Nocardia otitidiscaviarum and Nocardia cerradoensis. Nocardia cerradoensis was isolated from an invasive brain infection. Isolated bacteria were susceptible to majority of the tested antibiotics, except for 2 strains of Nocardia cyriacigeorgica and Nocardia cerradoensis. This was the first isolation of Nocardia cerradoensis of human infection in Asia. Patients with PV are susceptible to nocardiosis, similar to other immunocompromised patients.

CONCLUSION

Pemphigus Vulgaris is a severe autoimmune disease which is treated by a high dosage of corticosteroids. Opportunistic infections are one of the greatest challenges of these patients. One of the neglected agents of opportunistic infection in this disorder is Nocardiosis which can cause a high mortality rate in PV patients.

Brain metastasis or nocardiosis? A case report of central nervous system Nocardiosis with a review of the literature

Nocardiosis is an infection caused by the gram-positive bacterium Nocardia, which typically manifests as an isolated pulmonary or systemic disease. Of note, Nocardia has a predilection for the central nervous system (CNS) involvement, which is more commonly seen in systemic nocardiosis rather than as an isolated CNS infection. According to the Centers for Disease Control and Prevention, the estimated incidence of nocardiosis is only 500 to1000 cases in the USA every year, with cases mostly found in immunocompromised people, although infection in the immunocompetent may also occur. Here, we present a case of an immunocompromised patient who presented with neurologic symptoms and intracranial lesions initially concerning metastatic disease. Upon further investigation, the patient was found to have CNS nocardiosis with bacteremia. This is an extremely rare presentation given the lack of concurrent pulmonary and cutaneous involvement. The insidious onset and rarity of nocardiosis can result in a delayed or missed diagnosis. Early recognition is crucial as this is a potentially life-threatening illness. After obtaining adequate culture specimens, empiric treatment must be started expeditiously, keeping in mind the diversity of the Nocardia species and their antimicrobial resistance patterns.

Long-term use of liposomal nebulized amikacin and tedizolid for the treatment of disseminated nocardiosis after allogeneic hematopoietic stem cell transplantation

Nocardiosis is a life-threatening opportunistic infection in immunocompromised patients. Herein, we present successful adjunctive use of liposomal nebulized amikacin and tedizolid in a recipient of allogeneic hematopoietic stem cell transplantation infected with Nocardia nova complex who presented multiple complications to conventional therapeutic options.

How do I manage nocardiosis?

BACKGROUND

Nocardiosis is a rare infection that is often difficult to treat and may be life-threatening. There is no consensus on its management.

OBJECTIVES

Our aim was to provide the current evidence for the diagnosis and management of individuals with nocardiosis, and to propose a management approach for this uncommon infection.

SOURCES

We systematically searched the medical literature on nocardiosis for studies published between 2010 and 2020 and describing ten or more individuals.

CONTENT

Nocardiosis, a primarily opportunistic infection which may occur in immunocompetent persons, most commonly involves the lungs and frequently disseminates to other sites including the central nervous system. The reference standard for Nocardia species identification is molecular biology, and the preferred method for antibiotic susceptibility testing (AST) is broth microdilution. Monotherapy seems appropriate for patients with primary skin nocardiosis or non-severe pulmonary disease; we reserve a multidrug regimen for more severe infections. Species identification and AST results are often missing at initiation of antibiotics. Trimethoprim-sulfamethoxazole is the preferred agent for initial therapy, because Nocardia is very often susceptible to this agent, and because it has been the keystone of nocardiosis treatment for years. Linezolid, to which Nocardia is almost always susceptible, may be an alternative. When combination therapy is required, the repertoire of companion drugs includes third-generation cephalosporins, amikacin and imipenem. Therapeutic modifications should take into account clinical response to initial therapy and AST results. Treatment duration of 6 months is appropriate for most situations, but longer durations are preferred for disseminated nocardiosis and shorter durations are reasonable in low-risk situations. Secondary prophylaxis may be considered in selected individuals with permanent immunosuppression.

IMPLICATIONS

We hereby provide the clinician with an easy-to-use algorithm for the management of individuals with nocardiosis. We also illuminate gaps in evidence and suggest future research directions.

Nocardiosis in glomerular disease patients with immunosuppressive therapy

Background

Glomerular disease patients have a high risk of infection, which contributes to the progression of disease per se and mortality, especially in those with long-term use of glucocorticoids and (or) immunosuppressive agents. Cases of sporadic nocardiosis have been reported in glomerular disease patients, and this observation was conducted to comprehensively understand the manifestations of and treatments for nocardiosis, which is commonly misdiagnosed as pneumonia or tuberculosis or even as lung cancer or metastatic tumors in glomerular disease patients.

Methods

We reviewed the demographic characteristics, laboratory abnormalities, radiological features, and treatments of 7 patients with nocardiosis and glomerular disease receiving steroids and immunosuppression therapy at the nephrology department of the Second Xiangya Hospital between 2012 and 2019.

Results

It was found that all 7 patients had been receiving methylprednisolone for renal disease at a median dose of 20 mg per day and a median duration of 4 months before developing nocardiosis. There were 4 males and 3 females, and the median age was 52.14 years. All 7 patients had hypoalbuminemia at the time of admission. In addition, various cystic abscesses in the subcutaneous tissue, with or without lung and brain involvement, were observed in these patients. Encouragingly, body temperatures returned to normal, and subcutaneous abscesses diminished or disappeared with compound sulfamethoxazole treatment alone or in combination with linezolid, imipenem and mezlocillin/sulbactam.

Conclusions

It was shown that multisite abscesses, including subcutaneous, pulmonary and cerebral abscesses, were the common manifestations of nocardiosis in glomerular disease patients. Sulfonamide was the first-line antibiotic therapy for nocardiosis, and combinations of other antibiotics were also needed in some serious cases.

Endogenous Nocardial Endophthalmitis Misdiagnosed as Giant Cell Arteritis

Purpose

Endogenous endophthalmitis is uncommon but potentially dangerous. We present a fatal presentation of endogenous Nocardial endophthalmitis in the context of steroid use for treatment of giant cell arteritis.

Case Presentation

An 84-year-old Caucasian female presented to the local emergency room with severe headaches, myalgia and shoulder and calf muscle pain. She was treated for a presumed diagnosis of giant-cell arteritis with corticosteroids and subsequently developed an intense retro-orbital pain in the right eye. Fundus examination revealed a white, vascularized chorioretinal mass at the equator of the eye in the inferotemporal quadrant. Antibiotics were given and a vitrectomy was performed. The culture of the vitreous showed Nocardia nova and a diagnosis of disseminated Nocardiosis was made.

Conclusion and Significance

Although uncommon, it is important that ophthalmologists are aware of Nocardial infections as a differential diagnosis of retinal mass, particularly in immunocompromised patients.

Nocardia seriolae: a serious threat to the largemouth bass Micropterus salmoides industry in Southwest China

Nocardia seriolae is the causative agent of nocardiosis in both marine and freshwater fish. Here, we report on multiple outbreaks of nocardiosis associated with elevated mortality (23-35%) in farmed largemouth bass in Sichuan, China, from 2017 to 2018. A total of 9 strains isolated from diseased largemouth bass were identified as N. seriolae by phenotypic characterization, 16S rRNA and hsp65 gene sequence analysis. The clinical signs of infected largemouth bass included hemorrhage, skin ulcers and prominent tubercles varying in size in the gill, liver, spleen and kidney. Experimental infection indicated that these isolates were the pathogens responsible for the mortalities. In vitro antibacterial activities of 12 antibiotics against N. seriolae isolates were determined as minimum inhibitory concentrations. Histopathological observation of diseased fish infected with N. seriolae showed necrotizing granulomatous hepatitis, nephritis, splenitis, epithelial hypertrophy and hyperplasia with degenerative changes of the epithelium in the gill. Large quantities of bacterial aggregates were found in the necrotic area of the granuloma by Lillie-Twort Gram stain and immunocytochemistry. Our findings indicated that N. seriolae is a serious threat to the largemouth bass Micropterus salmoides industry in Southwest China.

Revisiting nocardiosis at a tertiary care institution: Any change in recent years?

OBJECTIVE

To analyse relevant changes in incidence, clinical and microbiological characteristics of nocardiosis over the last 24 years at the current institution.

MATERIALS AND METHODS

The clinical records of patients with nocardiosis (2006-2018) were reviewed and then compared with a previous cohort (1995-2006). Nocardia isolates were identified by 5'-end-16S-rRNA-gene-PCR targeting the first 500 bp of the gene and sequencing. Susceptibility tests were determined by broth microdilution (CLSI guidelines).

RESULTS

Forty-two patients (64.3% male) with nocardiosis were evaluated in the recent cohort: 51.2% had COPD, 43.9% were on corticosteroid therapy and 31.7% had cancer. The incidence of nocardiosis varied from 6.3 to 7.1/100,000 admissions (p = 0.62). There was a decrease in HIV patients (27% vs. 4.9%, p = 0.01) and solid organ transplantation (SOT) recipients (18.9% vs. 2 .4%, p = 0.01). Cases with pulmonary involvement had increased (70.3% vs. 90.5%, p = 0.04). Nocardia species were similar but the most common were N. cyriacigeorgica (32.4% vs. 40.5%, p = 0.49) and N. farcinica (24.3% vs. 14.3%, p = 0.39). Antibiotic resistance remained stable: cotrimoxazole (10.8% vs. 5.7%, p = 0.68), imipenem (5.4% vs. 5.6%, p = 1.0); amikacin and linezolid were 100% active. No differences were found in breakthrough nocardiosis (21.6% vs. 9.8%, p = 0.21) or related mortality (21.6% vs. 21.4%, p = 1.0). The multivariate analysis confirmed that nocardiosis caused by N. farcinica is a risk factor for poor outcome (p = 0.045).

CONCLUSIONS

Nocardiosis incidence has remained stable. It mainly affected elderly patients with chronic respiratory conditions and those on corticosteroid treatment. Infections in HIV and SOT patients have practically disappeared. Pulmonary involvement remains the most common area to be affected. Nocardiosis caused by N. farcinica is apparently a risk factor for poor clinical outcome.

Nocardiosis Associated with Primary Immunodeficiencies (Nocar-DIP): an International Retrospective Study and Literature Review

PURPOSE

Nocardiosis is a life-threatening infectious disease. We aimed at describing nocardiosis in patients with primary immunodeficiency diseases (PID).

METHODS

This international retrospective cohort included patients with PID and nocardiosis diagnosed and/or published from Jan 1, 2000, to Dec 31, 2016. To identify nocardiosis cases, we analyzed PID databases from the French National Reference Center for PID (Paris, France) and the National Institute of Health (NIH, United States of America) and we performed a literature review on PubMed.

RESULTS

Forty-nine cases of nocardiosis associated with PID were included: median age at diagnosis of nocardiosis was 19 (0-56) years and most cases were observed among chronic granulomatous disease (CGD) patients (87.8%). Median time from symptoms to diagnosis of Nocardia infection was 20 (2-257) days. Most frequent clinical nocardiosis presentation was pneumonia (86.7%). Twelve-month mortality rate was 4.2%, and 11.9% of patients experienced a possible recurrence of infection. Nocardiosis more frequently led to the diagnosis of PID among non-CGD patients than in CGD patients. Non-CGD patients experienced more cerebral nocardiosis and more disseminated infections, but mortality and recurrence rates were similar. Highest incidences of nocardiosis among PID cohorts were observed among CGD patients (0.0057 and 0.0044 cases/patient-year in the USA and in France, respectively), followed by IL-12p40 deficiency.

CONCLUSIONS

Among 49 cases of nocardiosis associated with PID, most patients had CGD and lung involvement. Both mortality and recurrence rates were low.

Pulmonary nocardiosis: A Single Center Study

Objectives

Nocardiosis is a rare infection caused by Nocardia spp., a gram-positive bacteria non-commensal of the human flora. Nocardiosis usually presents with lung infection but may disseminate to other organs, most frequently the brain. The major risk factor is immunosuppression, but lung diseases also increase the risk of infection. Treatment with antibiotics is usually prolonged. In this study, we made a retrospective analysis of pulmonary nocardiosis cases and a review of the available literature.

Methods

We made a retrospective analysis of all pulmonary nocardiosis cases from 13 years (January 2005 to December 2017) in our institution, selecting patients from pulmonology and infectious diseases consultation.

Results

We found four patients diagnosed with pulmonary nocardiosis, three males (patients 1, 2 and 3) and one female (patient 4). Median age was 71 ± 15 years old. Different specimens were identified (N. cyriacigeorgica, Nocardia spp., N. nova, and N. wallacei/transvalensis). Bronchofibroscopy with bronchoalveolar lavage culture was the most frequent diagnostic procedure (patients 1 and 4). Only patient 2 presented an unfavorable response to treatment and died from septic shock.

Conclusions

Pulmonary nocardiosis has a good prognosis if diagnosed early and treated adequately. It should always be considered in the differential diagnosis of pulmonary infections concomitant with brain or other soft tissue lesion, especially in immunocompromised patients.

[Sporotrichoid nocardiosis by Nocardia brasiliensis]

Nocardia brasiliensis is a gram-positive, branched, aerobic, acid-resistant, rod-shaped bacillus that inhabits in soil, rotten organic matter and waters. Cutaneous nocardiosis in immunocompetent individuals can manifest in three different forms: actinomycetoma, superficial skin infection or lymphocutaneous infection. A case of an 85-year-old woman with an ulcerated lesion on the back of her left hand with erythematous papules in the lymphatic tract infected by N. brasiliensis is described. The microorganism was presumptively identified by conventional and inexpensive methods for a medium complexity laboratory at the species level. The morphological characteristics of colonies, the mold smell, a positive Kinyoun stain and the presence of aerial mycelium were the key tests to identify the genus. Species level identification was confirmed by mass spectrometry (MALDI-TOF MS). The trimethoprim-sulfamethoxazole treatment was effective as this agent was active in the susceptibility testing.

Diffuse primary cutaneous infection by Alternaria alternata in a liver transplant recipient with pulmonary nocardiosis: Importance of prompt identification for clinical resolution

Fungal infections are rare in the general population but are an emerging cause of disease in immunosuppressed patients, especially solid organ transplant recipients. Here, we report the case of a female Caucasian liver transplant patient who developed pulmonary nocardiosis two months after an episode of liver rejection. At the time of lung nocardiosis, she was being treated with tacrolimus and corticosteroids and suffered from diffuse papular skin lesions. She was initially suspected of having a cutaneous nocardial infection but culture examination revealed the presence of a dematiaceous fungus; Alternaria alternata. The prompt identification of the fungus and administration of oral Voriconazole resolved the skin infection with complete remission.

Intracranial peripherally enhancing lesions in cardiac transplant recipients: A rare case series and literature review

Intracranial peripherally enhancing lesions in immunosuppressed solid organ transplant recipients represent a unique diagnostic and management dilemma due to the vast array of differentials that demand consideration. Diagnosis of the underlying pathology is often guided by the use of magnetic resonance imaging (MRI). We present the first published case series of three cardiac transplant recipients with significantly atypical neuroradiological findings contrary to the tenets of contemporary literature. Our rare case series consists of: (1) A sterile Mycobacterium pyogenic abscess mimicking glioblastoma multiforme due to an immunosuppressed state (2) Epstein Barr Virus encephalitis masquerading as Central Nervous System Post-Transplant Lymphoproliferative Disorder (3) An unusual case of partially treated disseminated Nocardiosis warning of the need to consider the immunosuppressed state and partial treatment response obfuscating classical MRI appearances. We utilise these unprecedented cases as the basis of a literature review to understand the pathophysiology behind the peculiar imaging findings in this rarefied cohort of transplant recipients, and rationalise why the MRI findings in each instance contradicts the accepted imaging patterns. In the setting of potential unreliability of neuroradiology in this immunosuppressed unique subgroup, we hope to impart to clinicians that definitive diagnosis obtained by emergent neurosurgical intervention may be necessary to accurately and expediently guide further medical management.