Nocardia cyriacigeorgica Septicemia

Abstract

We report two cases of Nocardia cyriacigeorgica septicemia and disseminated infection in the setting of profound immunodeficiency. In both instances, diagnosis was rapidly facilitated by 16S rRNA gene sequencing of blood culture isolates. These constitute the first confirmed reports of Nocardia cyriacigeorgica bloodstream infection in humans.CASE REPORTS Case 1. The patient was a 69-year-old woman with type 2 diabetes mellitus, chronic lymphocytic leukemia, and hypogammaglobulinemia who presented to hospital "A" with a 3-week history of malaise, right-sided flank and pleuritic chest discomfort, left leg weakness, and an ataxic gait. She denied any fever, chills, cough, or weight loss. Baseline laboratory studies revealed neutrophilia, lymphocytosis, anemia, and hyponatremia. Radiologic studies demonstrated patchy and nodular infiltrates in the right lung, bilateral pleural effusions, multiple ring enhancing lesions in the cerebellum and cerebrum, and a right adrenal mass. Upon the patient's admission to hospital, three sets of BacT/Alert FAN (bioMerieux Inc., Durham, N.C.) aerobic and anaerobic blood cultures were collected, while the adrenal mass was biopsied to rule out infectious and noninfectious etiologies. After 2.5 days of incubation, the aerobic bottle of one of the blood culture sets demonstrated the presence of a partially acid fast, branching, rod-shaped bacterium that formed dry white colonies after overnight growth on 5% sheep blood and Sabouraud dextrose agar media. Respiratory samples were not collected for microbiological analysis. A diagnosis of disseminated nocardiosis was subsequently made, after which the patient received empirical therapy with intravenous meropenem (1 g every 8 h) and oral trimethoprim-sulfamethoxazole (TMP-SMX) (160 and 800 mg, respectively, twice daily). Using Microseq 500 kits and an ABI Prism 3100 genetic analyzer (Applied Biosystems, Foster City, CA), partial sequencing (first 500 bp) of the 16S rRNA gene of the blood culture was successful. A BLAST search (http://www.ncbi.nlm.nih.gov/BLAST/) of the GenBank database revealed 100% homology of our patient's sequence with that of five strains of Nocardia cyriacigeorgica (GenBank accession numbers AB094578, AB115955, AY244782, AY262326, and AB094580) and 98.1% and 97.9% homology with two other N. cyriacigeorgica strains (GenBank accession numbers AF430027 and AF282889, respectively). The adrenal biopsy culture was also positive for N. cyriacigeorgica. The isolate was susceptible to TMP-SMX (MICs, Յ2/38 g/ml), imipenem (MIC, 2 g/ml), and amikacin (MIC, Յ16 g/ml) based on Clinical and Laboratory Standards Institute (CLSI; formerly NCCLS) broth microdilution susceptibility testing (13). The patient's clinical condition gradually improved over the course of her stay in the hospital, but she remained on intravenous meropenem and oral TMP-SMX for several weeks thereafter through the regional home intravenous therapy program. Follow-up radiologic investigations 2 months post-hospital discharge demonstrated complete resolution of t...

Nocardia cyriacigeorgica , an Emerging Pathogen in the United States

“…Recent reviews of collections of Nocardia clinical isolates by genotypic methods have found that a significant proportion, originally identified by routine phenotypic and chemotaxonomic methods, belong to a new species, Nocardia cyriacigeorgica (18,27,29,35). This species was first described in 2001 (38), and strains of N. cyriacigeorgica have since been recovered as the etiologic agent of human infection in Western Europe, Greece, Turkey, Japan, Thailand, and Canada (1,3,6,7,11,17,18,22,27,35,39). Most cases of infection have occurred in the context of human immunodeficiency virus-related or iatrogenic immune suppression.…”

Imipenem-Resistant Nocardia cyriacigeorgica Infection in a Child with Chronic Granulomatous Disease

“…In addition to having sulfonamide susceptibility, type VI complex strains are generally susceptible to amikacin, broadspectrum cephalosporins, imipenem, and linezolid but resistant to amoxicillin-clavulanate, ampicillin, ciprofloxacin, and clarithromycin (3). Linezolid appears to be the most effective agent in vitro against Nocardia, but clinical experience is limited (5). Other complexes, such as those corresponding to the highly antimicrobial-resistant N. transvalensis (type IV) and N. farcinica (type V), have been described.…”

“…previously classified as having a type VI drug pattern (3). It appears that N. cyriacigeorgica has a drug pattern identical to the N. asteroides drug susceptibility pattern type VI, which accounts for approximately 60% of clinical N. asteroides complex strains (5). In addition to having sulfonamide susceptibility, type VI complex strains are generally susceptible to amikacin, broadspectrum cephalosporins, imipenem, and linezolid but resistant to amoxicillin-clavulanate, ampicillin, ciprofloxacin, and clarithromycin (3).…”

A Case of Pulmonary Nocardiosis Due to Nocardia cyriacigeorgica

“…8 In addition, isolates of N. cyriacigeorgica have been identified by 16S r RNA gene sequence analysis from patients with disseminated disease in Canada, France, Greece and The Netherlands. [9][10][11][12][13] In these paper we described a pneumonia case in which N. cyriacigeorgica is causative agent.…”