A Case of Nocardia farcinica Pneumonia and Mediastinitis in an Immunocompetent Patient

Abstract

Nocardia species are aerobic, gram-positive pathogens found worldwide in soil. Nocardia is considered an opportunistic pathogen, and its infection mostly occurs in immunocompromised patients. We report a case of Nocardia farcinica induced mediastinitis and pneumonia that occurred in a 64-year-old male patient who had no significant medical history except for hypertension. He visited another hospital with a complaint of dyspnea and left chest wall pain. The symptoms arose 7 days ago without any trauma and they worsened. A mediastinal mass was found on computed tomography scan. After being transferred to our hospital for further evaluation, he was diagnosed with mediastinitis and pneumonia. As N. farcinica was found to be the causative organism by 16S rRNA sequencing, proper antibiotic therapy including trimethoprim/sulfamethoxazole was initiated immediately. After this, the patient improved and he was discharged. If an infection has a disseminating course, nocardiosis cannot be excluded even in immunocompetent patients. Once the diagnosis is established, prompt antibiotic therapy should be performed based on the severity.

Severe pneumonia due to Nocardia otitidiscaviarum identified by mass spectroscopy in a cotton farmer

“…[23] Although increasing numbers of Nocardia species including N otitidiscaviarum complex have developed increasing resistance and demonstrated inconsistent susceptibility to trimethoprim-sulfamethoxazole, sulfonamides remain the standard antimicrobial agents for the treatment of nocardiosis to date. [24,25] Most N otitidiscaviarum isolates are also reported to be resistant to and beta-lactams like ampicillin, amoxicillin-clavulanic acid, and imipenem, but are usually susceptible to amikacin and the fluoroquinolones.…”

“…[27] Although the optimal treatment protocol of N otitidiscaviarum still unknown, a combination of sulfonamides and amikacin with a carbapenem or a 3rd-generation cephalosporin are suggested for severe or disseminated infections. [20,23] Similarly in this case, combined therapy (amikacin, imipenem, and trimethoprim-sulfamethoxazole) was administered in accordance with the sensitivity test on the 6th hospital day after N otitidiscaviarum was identified. However, the mortality rate in pulmonary nocardiasis patients is 15% to 30%, even in severe patients up to 50%.…”

Cloning, Expression, Invasion, and Immunological Reactivity of a Mammalian Cell Entry Protein Encoded by the mce1 Operon of Nocardia farcinica

“…Nocardia genus bacteria are Gram-positive filamentous rod, aerobic pathogens found in soil and water worldwide ( Scharfen et al, 2010 ). They are considered opportunistic pathogens, affecting predominantly immunocompromised patients, including patients with AIDS and transplant recipients ( Kim et al, 2016 ). Pulmonary disease is the most common presentation of Nocardia in immunosuppressed patients and approximately one-third of affected patients have a disseminated disease ( Ambrosioni et al, 2010 ; Kandi, 2015 ; Scorey and Daniel, 2016 ).…”

Fatal pulmonary infection by trimethoprim-sulfamethoxazole resistant Nocardia otitidiscaviarum: report of two cases and review

“…We found resistance to TMP-SMX in seven of the seventeen (41.2%) cases where antibiotic susceptibility had been performed. Studies have suggested a combination of sulphonamides and amikacin with a carbapenem or a 3 rd generation cephalosporin as optimum therapy for severe or disseminated infections with N. otitidiscaviarum [38,39]. CLSI recommends broth microdilution as a preferred method for susceptibility testing for Nocardia spp.…”