Disseminated nocardiosis caused by Nocardia abscessus in an HIV-infected patient: first reported case

Unusual presentation of Nocardia abscessus infection in an immunocompetent patient

Introduction. Nocardia infections are being increasingly reported in both immunocompetent and immunocompromised patients. We describe a case of Nocardia abscessus infection with an atypical presentation in an immunocompetent patient.

Case Presentation. A previously healthy 47-year-old gentleman presented with hiccups and paroxysmal spasms. Imaging revealed a pulmonary nodule, for which he underwent surgical resection. Pathologic evaluation demonstrated evidence of local inflammation, with growth of Nocardia abscessus on tissue cultures.

Conclusion. Nocardia abscessus may have atypical presentations in immunocompetent patients. Further research is needed to understand the factors leading to Nocardia infections in immunocompetent patients.

[Cerebral and pulmonary nocardiosis to Nocardia abscessus in an immunocompetent Algerian patient]

Nocardial brain abscess is often occurring in immunocompromised patients. It is uncommon in immunocompetent individuals. Here, the authors describe a case of cerebral and pulmonary nocardiosis mimicking a metastatic tumor in an apparently health 40-year-old Algerian male. The patient presented multiple brain abscess revealed by inaugural epileptic seizure. He was afebrile and presented with left hemiparesis. Staging imaging showed a nodular lung lesion in the apical segment of the right lower lobe. The patient underwent double craniotomy for resection of the lesion. Culture of the resected specimen isolated Nocardia abscessus. The patient was initially started on intravenous trimethoprim-sulfamethoxazole and intravenous amikacine. He was switched to oral trimethoprim-sulfamethoxazole. He finished seven months of antibiotic therapy with a good clinical response. Imaging revealed reduction in the brain abscess and a complete resolution of the lung lesion. Cotrimoxazole was stopped after twelve months of therapy. After two years, the health status of our patient improves day after day. He is however regularly under medical supervision for control exams.

Nocardia abscessus brain abscess in an immunocompetent host

Nocardia brain abscesses typically occur in immunocompromised patients. Most cases of nocardiosis are caused by the Nocardia asteroides complex and Nocardia brasiliensis. Here, we present a patient with a Nocardia abscessus brain abscess. The diagnosis was confirmed by DNA sequencing, and the organism was susceptible to linezolid, clarithromycin, ceftriaxone, imipenem, tobramycin, amikacin, minocycline and sulfamethoxazole. The patient was successfully treated medically in combination with surgical excision.

Unusual infections: Femoral abscess due to Nocardia abscessus in a patient suffering from metastatic peripheral bronchial carcinoma and hygienic consequences

During the course of a peripheral bronchial carcinoma with pulmonary and cerebral metastases a femoral abscess developed in a 49 year-old patient after radio- and chemotherapy. A bacterial strain, which was isolated four times from a deep wound of the left thigh was tentatively identified as a member of the genus Nocardia on the basis of selected phenotypic and chemotaxonomic characteristics. The isolate was confirmed to belong to Nocardia abscessus by 16S rRNA gene sequencing. This species had previously been described as the causative agent of soft tissue infections. Although rare, nocardia soft tissue infections as complication of systemic nocardiosis are typical air born infections of immuncompromised patients and need specific attention. Infection prevention can be realized by restriction of soil and aerosol (builder's dust) together with antibiotic intervention (oral administration of trimethoprim/sulfamethoxazole).

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 nocardiosis with psoas abscess in a patient with AIDS: first reported case

Psoas muscle abscess is an uncommon infection that have been diagnosed increasingly in the last years. We present a case of a patient with advanced human immunodeficiency virus infection who developed a disseminated infection due to Nocardia asteroides sensu stricto type VI with psoas abscess. To our knowledge no other cases of Nocardia psoas abscess in the setting of HIV infection have been reported in the literature.

In vitro activity of fluoroquinolones against clinical isolates of Nocardia identified by partial 16S rRNA sequencing

Fluoroquinolones have several properties that make them potentially attractive candidates for the treatment of Nocardia infections, but information regarding their in vitro activity is limited. Minimum inhibitory concentrations (MIC) of five fluoroquinolones and other antimicrobials were determined by the reference broth dilution and E-test methods for 33 consecutive clinical isolates of Nocardia speciated by 16S rRNA gene sequences. The isolates included: Nocardia cyriacigeorgica (n = 6), N. nova (n = 8), N. farcinica (n = 8), N. brasiliensis (n = 3), N. asteroides (n = 4), and N. veterana (n = 4). MIC50/MIC90 results for ciprofloxacin, gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin by broth dilution were 32/32, 2/4, 1/4, 32/32, and 2/2 microg/ml, respectively. The MICs by broth dilution and E-test were within a two-fold doubling dilution for 94%, 97%, 97%, 100%, and 100% of isolates for ciprofloxacin, gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin, respectively. For ciprofloxacin, the E-test results showed either complete categorical agreement or minor error compared to the reference broth dilution method for 97% (32/33) of the isolates. For other fluoroquinolones, using Streptococcus pneumoniae breakpoints, 94% (124/132) of MIC results by E-test showed either complete agreement or minor error compared to the reference broth dilution method. Fluoroquinolones show variable in vitro activity against clinical isolates of Nocardia spp., and MICs determined by the E-test show reasonable agreement with those determined by the reference broth dilution method.

Clinical and microbiological features of nocardiosis 1997–2003

Nocardiosis has been believed to be caused by the members of the Nocardia asteroides complex and the Nocardia brasiliensis species. However, recent advances in genotypic identification have shown that the genus exhibits considerable taxonomic complexity and the phenotypic markers used in the past for its identification can be ambiguous. The aim of this study was to assess the species distribution of Nocardia isolates and to determine whether there are differences in pathogenicity or antimicrobial susceptibility between the different species identified. Nocardia isolates obtained over a 7 year period were retrospectively reviewed. The isolates were identified genotypically, their antibiotic susceptibility was tested and the clinical data of the 27 patients were retrieved. Eight different Nocardia species were identified: Nocardia farcinica (n=9), Nocardia abscessus (n=6), Nocardia cyriacigeorgica (n=6), Nocardia otitidiscaviarum (n=2), Nocardia nova (n=1), N. nova complex (n=1), Nocardia carnea (n=1) and Nocardia transvalensis complex (n=1). All species were susceptible to co-trimoxazole but different patterns of susceptibility to other agents were observed. All patients had active comorbidities at the time of infection. A total of 19 patients were immunosuppressed, due to human immunodeficiency virus infection, chronic corticosteroid therapy, immunosupressive therapy or haematological malignancies. Six patients displayed a Charlson comorbidity index score above 4. Global mortality was 50 % while attributable mortality was 34.6 %. Patients infected with N. farcinica – the most resistant species – had the highest Charlson index score and the highest mortality rate. Accurate identification of the species and susceptibility testing of Nocardia isolates may play an important role in diagnosis and treatment.

Molecular diagnosis of culture-negative cerebral nocardiosis due to Nocardia abscessus

We describe a case of culture-negative cerebral nocardiosis in a 34-year-old immunocompetent man who presented multiple cerebral abscesses. All bacteriologic cultures were negative. Nocardiosis was diagnosed by using a direct genus-specific 16S rDNA amplification method, and Nocardia abscessus was identified by hsp65 sequence analysis. The patient is alive and well on imipenem and doxycycline therapy, 14 months after onset.