[Nocardiosis: A retrospective case series of 19 patients]

Pleuropulmonary nocardiosis, an unusual radiological presentation: Case report

Nocardiosis is caused by strict aerobic filamentous bacteria of the genus Nocardia belonging to the order Actinomycetales with Actinomyces, Streptomyces and Mycobacterium. The radio-clinical presentation in the chest is often misleading. We report a case of pulmonary nocardiosis with an unusual radiological presentation. A 54-year-old patient, chronic smoker, never treated for pulmonary tuberculosis, who presented with a chronic cough complicated by moderate hemoptysis, all evolving in a context of altered general condition and feverish sensations. The radiological aspect was in favor of a hydro-pneumothorax, the pleural puncture brought back a chocolate colored purulent liquid with the presence of numerous yellow grains and the direct examination showed numerous branched gram-positive bacilli. The bacteriological study allowed to retain the presumptive diagnosis of nocardiosis, the patient was put under antibiotic treatment with a clear clinical and radiological improvement. This observation illustrates the diagnostic difficulty of pulmonary nocardiosis and emphasizes the importance of thinking about nocardiosis in front of any dark thoracic syndrome.

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.

Asymptomatic cerebral abscesses after pleuropulmonary Nocardia farcinica infection

We report the case of a 68-year-old man with long-term receipt of steroid therapy who was diagnosed with cerebral abscesses and pulmonary nocardiosis. This patient displayed only respiratory symptoms. Confirmation of Nocardia farcinica species was achieved by specific PCR sequencing of the 16S ribosome RNA in bronchoalveolar lavage cultures. Cerebral magnetic resonance imaging revealed abscesses. Antibiotic therapy with trimethoprim/sulfamethoxazole was prescribed given the results of susceptibility tests and was maintained for 12 months, with no evidence of relapse afterwards.

Assessment of VITEK® MS IVD database V3.0 for identification of Nocardia spp. using two culture media and comparing direct smear and protein extraction procedures

We assessed the performance of the VITEK® MS IVD V3.0 matrix-assisted laser desorption ionization - time of flight mass spectrometry (MALDI-ToF MS) V3.0 database for the identification of Nocardia spp. as compared with targeted DNA sequencing. A collection of 222 DNA sequence-defined Nocardia spp. strains encompassing 18 different species present or not in the database was tested. Bromocresol purple agar (BCP) and Columbia agar +5% sheep's blood (COS) culture media were used together with two different preparation steps: direct smear and a "3 attempts" procedure that covered (1) spotting of an extract, (2) new spotting of the same extract, and (3) spotting of a new extract. The direct smear protocol yielded low correct identification rates (≤ 15% for both media) whereas protein extraction yielded correct identification results (> 67% regardless of the media used.). The use of 2 additional attempts using repeat or new extracts increased correct identification rates to 87% and 91% for BCP and COS, respectively. When using the 3 attempts procedure, the best identification results, independent of media types, were obtained for N. farcinica and N. cyriacigeorgica (100%). Identification attempts 2 and 3 allowed to increase the number of correct identifications (BCP, +20%; COS, +13%). The enhancement in performance during attempts 2 and 3 was remarkable for N. abscessus (81% for both media) and low prevalence species (BCP, 70%; COS, 85%). Up to 3.4% and 2.4% of the strains belonging to species present in the database were misidentified with BCP and COS media, respectively. In 1.9% of the cases for BCP and 1.4% for COS, these misidentifications concerned a species belonging to the same phylogenetic complex. Concerning strains that are not claimed in the V3.0 database, N. puris and N. goodfellowi generated "No identification" results and 100% of the strains belonging to N. arthritidis, N.cerradoensis, and N. altamirensis yielded a misidentification within the same phylogenetic complex. Vitek® MS IVD V3.0 is an accurate and useful tool for identification of Nocardia spp.

Updates on Nocardia Skin and Soft Tissue Infections in Solid Organ Transplantation

PURPOSE OF REVIEW

Due to their immunocompromised status, solid organ transplant (SOT) recipients are at risk for Nocardia infections. These infections often necessitate early invasive diagnostics alongside prolonged, often combination antimicrobial therapy. This review summarizes the importance of this pathogen in skin and soft tissue infections (SSTIs) in SOT recipients inclusive of recently reported cases in the literature and an update on the epidemiology, diagnostics, and management.

RECENT FINDINGS

Six studies with 13 isolated SSTIs due to Nocardia have been published in the last 5 years in SOT recipients. The most common underlying type of transplant was kidney and time from transplantation to infection varied from 6 months to 16 years. Misdiagnosis was frequent. Available identified species included N. brasiliensis (2), N. farcinica (2), N. flavorosea (1), N. abscessus (1), N. anaemiae (1), N. asteroides (1), N. nova (1), and N. vinacea (1). Treatment choice and duration varied widely, and trimethoprim-sulfamethoxazole was utilized most often with no documented infection relapse. Nocardia SSTIs can occur both in isolation and as a component of a disseminated infection. Overall, isolated Nocardia SSTIs are uncommon in SOT recipients and are often initially misdiagnosed. They present multiple challenges to the clinician including evaluation for potential co-pathogens and/or non-infectious processes and ruling out the presence of disseminated infection. While trimethoprim-sulfamethoxazole remains the agent of choice for management of most isolated SSTIs, therapy must be tailored to the individual patient based on species-specific susceptibility patterns and formal susceptibility testing, site(s) of infection, and patient tolerability.

[Hemophagocytic lymphohistiocytosis with granulomatosis and diffuse T-cell infiltration associated with disseminated Nocardiosis and pulmonary infection due to Streptomyces spp]

INTRODUCTION

Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome frequently secondary to infectious disease, especially in immuno-compromised patients. We report a HLH secondary to disseminated nocardiosis and Streptomyces spp pulmonary infection.

CASE REPORT

A 69-years-old women had recent subcutaneous nodules of the forearms and loins associated with peripheral neuropathy and pulmonary nodule of the right upper lobe. Cutaneous biopsy revealed granuloma. Cutaneous lesions worsened and the patient developed a HLH with probable cardiac and neurological involvement, associated with cutaneous granulomatosis and diffuse polyclonal lymphocyte proliferation. Nocardia PCR was positive in cutaneous biopsy. Pulmonary samples revealed Streptomyces in culture and Nocardia in PCR. The evolution under antibiotic treatment was favorable.

CONCLUSION

Recent diagnosis of HLH without obvious etiology should lead to etiological investigation, including the search for infections with slow-growing bacteria such as Nocardia or Streptomyces spp.

[Disseminated nocardiosis caused by Nocardia nova with brain abscesses and osteomyelitis in an immunocompetent patient]

INTRODUCTION

Nocardia is an opportunist bacteria involved in patients with cellular immunodepression or chronic lung disease. The most frequent portals of entry are the respiratory tract by inhalation or direct inoculation through a cutaneous effraction. Nocardiosis may be localised or disseminated.

CASE REPORT

We report a rare case of disseminated nocardiosis to Nocardia nova with pulmonary, cutaneous, cerebral attacks and femoral osteomyelitis. The diagnosis was confirmed by prolonged cultures of the bronchoalveolar fluid and the pus extracted from a cutaneous lesion. The outcome was favorable under adapted and prolonged antibiotherapy with imipenem and amikacine and then cotrimoxazole.

CONCLUSION

This observation is original because it involves a immunocompetent patient with an association of two exceptional locations for N. nova: brain abscesses and femoral osteomyelitis. Screening for cerebral involvement should be systematic, even in the lack of neurological signs. An adapted and prolonged antibiotherapy must be conducted.