An improved screening technique for isolation of Nocardia species from sputum specimens

Clinical characteristics of hospitalized patients with Nocardia genus detection by metagenomic next generation sequencing in a tertiary hospital from southern China

OBJECTIVE

As an opportunistic pathogen, Nocardia often occurring in the immunocompromised hosts. As the unspecifc clinical presentation and low identification rate of the culture dependent methods, Nocardia infection may be under-diagnosis. Recent study have reported physicians could benefit from metagenomic next-generation sequencing (mNGS) in Nocardia diagnosis. Herein, we present patients with a positive detection of nocardiosis in mNGS, aiming to provide useful information for an differential diagnosis and patients management.

METHODS

A total of 3756 samples detected for mNGS from March 2019 to April 2022 at the Fifth Affifiliated Hospital of Sun Yat-sen University, were screened. Clinical records, laboratory finding, CT images and mNGS results were reviewed for 19 patients who were positive for Nocardia genus.

RESULTS

Samples from low respiratory tract obtained by bronchoscope took the major part of the positive (15/19). 12 of 19 cases were diagnosis as Nocardiosis Disease (ND) and over half of the ND individuals (7/12) were geriatric. Nearly all of them (10/12) were immunocompetent and 2 patients in ND group were impressively asymptomatic. Cough was the most common symptom. Nocardia cyriacigeorgica (4/12) was more frequently occurring in ND, followed by Nocardia abscessus (3/12). There are 3 individuals detected more than one kind of Nocardia species (Supplementary table 1). Except one with renal failure and one allergic to sulfamethoxazole, all of them received co-sulfonamide treatment and relieved eventually.

CONCLUSION

Our study deciphered the clinical features of patients with positive nocardiosis detected by mNGS. Greater attention should be paid to the ND that occurred in the immunocompetent host and the geriatric. Due to the difficulties in establishing diagnosis of Nocardiosis disease, mNGS should play a much more essential role for a better assessment in those intractable cases. Co-sulfonamide treatment should still be the first choice of Nocardiosis disease.

Isolation and Characterization of Nocardia Species from Pulmonary Nocardiosis in a tertiary hospital in China

The aim of this study was to investigate the clinical features, distribution and antimicrobial susceptibility of Nocardia species isolated from pulmonary nocardiosis cases in tertiary hospital in China. The species were collected from January 1, 2018 to May 31, 2019 and identified using MALDI-TOF MS or PCR. Antimicrobial susceptibility testing was performed using the broth microdilution method. Within the 44 Nocardia species, N. farcinica was the most frequently identified species (n = 36), followed by N. nova (n = 5), N. otitidiscaviarum (n = 1), N. cyriacigeorgica (n = 1), and N. transvalensis (n = 1). The top three predisposing factors of pulmonary nocardiosis were chronic obstructive pulmonary disease (45.5%), hypertension (34.1%), and tuberculosis (31.8%). All 44 Nocardia strains were susceptible to amikacin, trimethoprim / sulfamethoxazole, and linezolid. The resistance rates of Nocardia to amoxicillin-clavulanic acid, ciprofloxacin, clarithromycin, ceftriaxone, tobramycin, and imipenem were 4.5%, 9.1%, 79.5%, 72.7%, 63.6%, and 38.6%, respectively. Two Nocardia strains had decreased sensitivity to trimethoprim / sulfamethoxazole. In conclusion, N. farcinica was the most frequently isolated Nocardia species in the First Hospital of Changsha. All isolated clinical Nocardia strains showed susceptible to amikacin, trimethoprim / sulfamethoxazole, and linezolid, suggesting that these drugs can be primary therapeutic choices for treating Nocardia infections.

Nocardiosis from 1888 to 2017

The genus Nocardia is an aerobic bacterium, Gram-positive and catalase positive that is in Nocardiaceae family. This bacterium first described by Edmond Nocard in 1888 and is not in human commensal bacteria. To date, nocardiosis incidence is increasing due to increase population growth rate, increase in patients with immune disorder diseases and immunocompromised patients. We surveyed taxonomic position, isolation methods, phenotypic and molecular identification at the genus and species levels, antibiogram, treatment and epidemiology in the world from 1888 to 2017.

NOCARDIA CHOROIDAL ABSCESS: Risk Factors, Treatment Strategies, and Visual Outcomes

PURPOSE

To describe the risk factors, clinical course, ancillary test findings, treatment strategies, and visual outcomes of a series of patients with choroidal abscesses caused by endogenous Nocardia.

METHODS

This retrospective, consecutive noncomparative case series included all patients with Nocardia ocular infections at 3 tertiary medical centers over the past 20 years.

RESULTS

Five eyes in 5 patients were identified with choroidal abscesses because of Nocardia. All patients were immunocompromised: one suffered from AIDS and four had autoimmune disorders. Three of the 5 patients (60%) underwent systemic evaluation, and in all 3, nonocular nocardiosis was identified. Four patients (80%) underwent diagnostic ophthalmic surgery and received systemic and intravitreal antibiotics. The final patient deferred these interventions. Outcomes at the last follow-up examination were 20/25, 1/200, hand motion at 1 foot, and 2 patients underwent enucleation. Mean follow-up (± standard deviation) was 159 (± 103) days.

CONCLUSION

Immunosuppression is the most significant risk factor for developing Nocardia choroidal abscesses. Definitive diagnosis generally requires subretinal biopsy, which is also critical to implementing appropriate antibiotic therapy.

Endobronchial Enigma: A Clinically Rare Presentation of Nocardia beijingensis in an Immunocompetent Patient

Nocardiosis is an opportunistic infection caused by the Gram-positive weakly acid-fast, filamentous aerobic Actinomycetes. The lungs are the primary site of infection mainly affecting immunocompromised patients. In rare circumstances even immunocompetent hosts may also develop infection. Diagnosis of pulmonary nocardiosis is usually delayed due to nonspecific clinical and radiological presentations which mimic fungal, tuberculous, or neoplastic processes. The present report describes a rare bronchoscopic presentation of an endobronchial nocardial mass in a 55-year-old immunocompetent woman without underlying lung disease. The patient exhibited signs and symptoms of unresolving community-acquired pneumonia with a computed tomography (CT) scan that showed a space-occupying lesion and enlarged paratracheal lymph node. This patient represents the unusual presentation of pulmonary Nocardia beijingensis as an endobronchial mass. Pathology obtained during bronchoscopy demonstrated polymerase chain reaction (PCR) confirmation of nocardiosis. Symptoms and clinical findings improved with antibiotic treatment. This patient emphasizes the challenge in making the diagnosis of pulmonary nocardiosis, especially in a low risk host. A literature review presents the difficulties and pitfalls in the clinical assessment of such an individual.

First report of Nocardia beijingensis infection in an immunocompetent host in the United States

Here we describe the first reported case of Nocardia beijingensis infection in the United States, made rarer by its presence in an immunocompetent patient.

Salivary gland nocardiosis in an immunocompetent patient

We report a case of nocardiosis in an immunocompetent patient who presented with pain and multiple swellings in the face. Nocardia asteroides was isolated from the parotid and submandibular salivary glands. The patient was successfully treated by surgical drainage and oral administration of trimethoprim and sulfamethoxazole. To the best of our knowledge, this is the first reported case from India on N. asteroides affecting the salivary gland.

Nocardiosis: updated clinical review and experience at a tertiary center

Nocardiosis is a rare opportunistic disease that affects mainly patients with deficient cell-mediated immunity, such as those with acquired immunodeficiency syndrome (AIDS) or transplant recipients. Pulmonary disease is the most common presentation in immunosuppressed patients and approximately one-third have a disseminated disease. Primary cutaneous nocardiosis is more frequently observed in immunocompetent patients with direct inoculation of the organism through professional exposure. The diagnosis can be challenging, as signs and symptoms are not specific and a high index of clinical of suspicion is necessary. Although gram stain, modified acid-fast stain, and cultures remain as the standard diagnostic tools, novel molecular techniques have changed the taxonomy of these organisms and, in some instances, have facilitated their identification. The disease has a marked tendency to recur and a high morbidity and mortality rate in immunosuppressed patients. Treatment is usually prolonged and an associated antibiotic treatment is preferred for severe disease. Although sulfonamides in combination with other antibiotics are still the treatment of choice, other associations such as imipenem plus amikacin are preferred in some centers. Linezolid is a useful alternative therapeutic agent due to its oral availability and activity against most of the isolates studied. Twenty-eight cases of nocardiosis were diagnosed at our center between January 1989 and April 2009. We report the epidemiologic characteristics of Nocardia spp. observed in our institution and discuss the risk factors, clinical features, diagnosis, and management of the disease.

Disseminated Nocardia Otitidiscaviarum Infection in a Woman with Sickle Cell Anemia and End-Stage Renal Disease

Nocardia otitidiscaviarum is an uncommon human pathogen and a rare cause of pulmonary infection and bacteremia. We report a case of N. otitidiscaviarum bacteremia and pulmonary infection in a patient with end-stage renal disease (chronic kidney disease, stage 5) and sickle cell anemia. The epidemiology, pathogenesis, and treatment of Nocardia infections are discussed.

Nocardiosis: a review

Infections caused by Nocardia species are infrequent but challenging to clinicians. They cause a wide variety of diseases in both normal and immunocompromised patients. In recent years, the number of case reports has been increasing, and this can be attributed to the improvements in diagnostic capabilities and the higher clinical index of suspicion accompanying the increased prevalence of immunosuppressed patients. The treatment of nocardiosis also requires expertise. This report reviews the epidemiology, physiopathology, clinical manifestations, diagnosis and treatment of this aerobic bacterial disease.

[Nocardiosis in patients with HIV infection]

OBJECTIVE

To know the characteristics of nocardiosis in HIV infected patients.

PATIENTS AND METHODS

Retrospective analysis of HIV infected patients with a concomitant Nocardia spp. infection in nine Andalusian hospitals.

RESULTS

Eighteen cases of nocardiosis were studied. Seventeen patients were males and the mean age was 33.1 years. The risk behaviour for acquiring HIV infection was parenteral drug use in 15 patients (83.3%) and seven of them were active users when acquiring nocardiosis. The mean CD4 lymphocyte count was 66.3 106/l. The nocardiosis was manifested as disseminated disease in eight patients, only pulmonary disease in four cases, lymphocutaneous or soft-tissue nocardiosis in five, and pericarditis in the remaining patient. In the ten cases with pulmonary involvement, the chest X-ray revealed an alveolar, interstitial, and mixed pattern in five, three, and two patients, respectively. Most patients were treated with cotrimoxazole, with good clinical and microbiological responses in 88.8% of them. Some surgical procedures were required in six patients. Eight patients died, three on account of nocardiosis and five on account of other causes. There were three relapses.

CONCLUSIONS

Nocardia spp. infection is rare among patients with AIDS and occurs in immunosuppressed patients and drug users. The pulmonary, cutaneous, and soft-tissue were the most commonly observed forms in our series. Despite the high frequency of disseminated infection, the response to th