Empyema necessitans with osteomyelitis of fifth rib due to Nocardia farcinica: a case report

Background Empyema necessitans is a rare pulmonary condition described as the presence of pus in the pleural cavity with insidious extension into the surrounding soft tissue. The common microbial aetiology of empyema necessitans is tuberculosis. Nocardiosis a cause of empyema necessitans is rarely described in the literature. We herein present a case of an 80-year-old male with empyema necessitans with osteomyelitis of rib caused by Nocardia farcinica. Case presentation An 80-year-old male presented with complaints of soft swelling on the left lower posterior chest wall associated with dry cough and breathlessness on exertion. Computed Tomography (CT) thorax demonstrated empyema necessitans with features of left fifth rib osteomyelitis. Radiological guided aspiration of the chest wall collection revealed Nocardia species and surgical drainage of abscess was performed. Matrix-assisted laser desorption/ionization time-of-flight-mass spectrometry (MALDI-TOF-MS) identified the isolate as Nocardia farcinica. He was treated with three-drug regimen: Trimethoprim-sulfamethoxazole, amikacin and ceftriaxone for 2 weeks. After showing improvement patient was discharged and advised to take oral Trimethoprim-sulfamethoxazole for the next 6 months with periodic follow-up. Conclusions As our case demonstrates, the possibility of invasive Nocardiosis should not be overlooked even in immunocompetent patients. Clinicians should aware of this rare entity while treating patients with empyema necessitans.

Clinical Presentation, Management, and Outcomes of Patients With Brain Abscess due to Nocardia Species

Background Nocardial brain abscesses are rare, and published literature describing brain abscesses due to Nocardia species is limited to individual case reports or small series. We report one of the largest contemporary retrospective studies describing risk factors, diagnostic evaluation, management, and outcomes of nocardial brain abscess. Methods Retrospective review of all adults with brain abscess due to culture-confirmed Nocardia species at our institution between January 1, 2009, and June 30, 2020. Results Overall, 24 patients had nocardial brain abscesses during the study period. The median age at presentation was 64 years, and 62.5% were immunocompromised. Pulmonary and cutaneous infections were the most common primary sites of nocardial infection. All 24 patients had magnetic resonance imaging performed, and the frontal lobe was the most commonly involved. The most common organism isolated was Nocardia farcinica, followed by Nocardia wallacei and Nocardia cyriacigeorgica. Thirteen patients were managed with antimicrobial therapy alone, while 11 had both medical and surgical management. In all patients, dual therapy was recommended for the initial 6 weeks of treatment, and 22 patients received at least 1 oral agent as part of their final antibiotic regimen, predominantly trimethoprim-sulfamethoxazole and linezolid. Fourteen patients achieved complete clinical and radiographic resolution of infection. Conclusions Nocardia is an important cause of brain abscess in the immunocompromised host. Early diagnostic and therapeutic aspiration may help health care providers confirm the diagnosis, choose an appropriate antimicrobial regimen, and achieve source control.

Production and Characterization of Biosurfactant by Nocardia Species Isolated Form Soil Samples in Tehran

In this work, we report the Nocardia species were initially screened and then tested for their ability to produce biosurfactant. The biosurfactant production from the Nocardia species was determined by qualitative standard methods. The selected bacterial strain had better oil spreading and emulsifying activity and surface tension reduction. The biosurfactant producer strain was identified by 16S rRNA gene sequencing method. Using Fourier transform infrared spectroscopy and comparative analysis, the biosurfactant structure could be detected. Oil spreading tests and blue agar plate tests confirmed the presence of biosurfactant and extracellular anionic glycolipids. The E24% assay using olive oil showed strong emulsifying characteristic of extracted biosurfactant with a 100%. The stability of the biosurfactant produced in different conditions was significant. Nocardia coubleae was identified by biochemical methods and molecular methods.

Biodegradation of polycyclic aromatic hydrocarbons, phenol and sodium sulfate by Nocardia species isolated and characterized from Iranian ecosystems

Anthropogenic pollutants are known to have adverse effect on ecosystem, biodiversity and human health. Bioremediation is an option that has been widely used to remediate organic contaminants and reduce the risk of these hazardous materials. Microorganisms are readily available to screen and can be rapidly characterized to be applied in many extreme environmental conditions. Actinomycetes have a great potential for the production of bioactive secondary metabolites which have biodegradation activity. This study aimed to screen and characterize Nocardia species with biodegradation potential from diverse Iranian ecosystems. The isolates were screened from 90 collected environmental samples, identified and characterized using conventional and molecular microbiological methods including the PCR amplification and sequencing analysis of 16S rRNA and rpoB genetic markers. Growth rate in presence of pollutants, chromatography, Gibbs and turbidometric methods were used to determine bioremediation ability. A total of 19 Nocardia isolates were recovered from the cultured samples (21.1%) that belonged to 10 various species. The most prevalent Nocardia species was N. farcinica; 4 isolates (21%), followed by N. cyriacigeorgica and N. cashijiensis like; 3 isolates each (15.7%) and N. asteroides and N. kroppenstedtii; 2 isolates each (10.5%). Our results showed that various Nocardia species have great potential for bioremediation purposes, although they have not received much attention of the scholars for such significant usage.

Recurrent Empyema Thoracic Secondary to Pulmonary Nocardiosis in Immunocompetent Patients

Pulmonary nocardiosis is a rare disorder that mainly affects immune-compromised patients. We report a 37-year-old male who presented with persistent fever associated with productive cough. During this course of therapy, he had recurrent admissions for empyema thoracic. Clinically, his vital signs were normal. Blood investigations show leukocytosis with a significantly raised erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Sputum acid-fast bacilli (AFB) was scanty 1+ and sputum mycobacterium culture was negative. Chest X-ray (CXR) showed consolidative changes with mild to moderate pleural effusion on the right side. Skin biopsy was taken and showed Paecilomyces species. A computed tomography scan (CT thorax) was performed and revealed a multiloculated collection within the right hemithorax with a split pleura sign. Decortications were performed and tissue culture and sensitivity (C+S) growth of Nocardia species. And it is sensitive to sulfamethoxazole-trimethoprim and completed treatment for 4 months. This case highlights that pulmonary nocardiosis should be kept in mind in also immune-competent patients, especially in suspected cases of tuberculosis not responding to antitubercular therapy.

323. First case of Prosthetic joint infection due to Nocardia veterana-elegans

Background Nocardia are Gram-positive filamentous bacteria that cause Nocardiosis, a rare opportunistic infection. The most common site of infection is the lungs, with metastatic spread usually to the central nervous system. Prosthetic joint infection due to Nocardia is very rare. Methods We report the first case of prosthetic joint infection due to Nocardia veteran-elegans, and review the literature regarding Nocardia septic arthritis, with particular attention to prosthetic joint infection. Results The patient was a 35 year old male with history of Hodgkin’s Lymphoma for which he received chemotherapy previously, poorly controlled diabetes, motor vehicle accident in 2003 with right open tibial plateau fracture requiring hardware placement, who was admitted with a two week history of right knee pain and swelling. Knee aspiration revealed purulent fluid and synovial culture grew Nocardia species. He underwent right knee arthrotomy and debridement with removal of hardware. The Nocardia species was speciated as N. veterana-elegans, sensitive to trimethoprim/sulfamethoxazole, linezolid, clarithromycin, imipenem and amikacin. He was placed on oral linezolid for four weeks, which was then switched to oral trimethoprim/sulfamethoxazole, with a plan for a six month course of therapy. He has completed two months of therapy thus far and is doing well clinically. Nocardia is an uncommon cause of septic arthritis. We found only 37 cases reported in the English literature thus far. Amongst these, only six involved prosthetic joints, including our case, which is the first one to be caused by N. veterana-elegans.Three cases were caused by N. nova and one each by N. farcinica and asteroides. Septic arthritis due to Nocardia has a favorable outcome with a combination of surgical debridement and prolonged antimicrobial therapy of three to six months. For prosthetic joint infections, removal of hardware seems to carry a better prognosis. Trimethoprim/sulfamethoxazole is the preferred antimicrobial, including for bone and joint infection, although susceptibilities can vary amongst the different species. Conclusion Nocardia is an uncommon cause of septic arthritis. Prosthetic joint infection is very rare. Prognosis is fair with a combination of hardware removal and prolonged antibiotic therapy. Disclosures All Authors: No reported disclosures

Molecular Characterization and Antimicrobial Susceptibilities of Nocardia Species Isolated from the Soil; A Comparison with Species Isolated from Humans

Nocardia species, one of the most predominant Actinobacteria of the soil microbiota, cause infection in humans following traumatic inoculation or inhalation. The identification, typing, phylogenetic relationship and antimicrobial susceptibilities of 38 soil Nocardia strains from Lara State, Venezuela, were studied by 16S rRNA and gyrB (subunit B of topoisomerase II) genes, multilocus sequence analysis (MLSA), whole-genome sequencing (WGS), and microdilution. The results were compared with those for human strains. Just seven Nocardia species with one or two strains each, except for Nocardia cyriacigeorgica with 29, were identified. MLSA confirmed the species assignments made by 16S rRNA and gyrB analyses (89.5% and 71.0% respectively), and grouped each soil strain with its corresponding reference and clinical strains, except for 19 N. cyriacigeorgica strains found at five locations which grouped into a soil-only cluster. The soil strains of N. cyriacigeorgica showed fewer gyrB haplotypes than the examined human strains (13 vs. 17) but did show a larger number of gyrB SNPs (212 vs. 77). Their susceptibilities to antimicrobials were similar except for beta-lactams, fluoroquinolones, minocycline, and clarithromycin, with the soil strains more susceptible to the first three (p ≤ 0.05). WGS was performed on four strains belonging to the soil-only cluster and on two outside it, and the results compared with public N. cyriacigeorgica genomes. The average nucleotide/amino acid identity, in silico genome-to-genome hybridization similarity, and the difference in the genomic GC content, suggest that some strains of the soil-only cluster may belong to a novel subspecies or even a new species (proposed name Nocardia venezuelensis).

Clinical Nocardia species: Identification, clinical characteristics, and antimicrobial susceptibility in Shandong, China

Nocardia is a pathogen responsible for a variety of clinical infections. Here, we aimed to investigate the species distribution, clinical manifestations, and antimicrobial susceptibility of Nocardia species in two tertiary general hospitals over 3 years in China. In this retrospective study, a total of 27 Nocardia species were isolated from 27 individuals between January 2017 and December 2019. Nocardia isolates were identified to species level by mass spectrometry and 16S rRNA PCR sequencing. Clinical data were collected from medical records. Antimicrobial susceptibility was determined by standard Broth microdilution method. The 27 patients with Nocardia infection included 12 males and 15 females with a mean age of 60.11 years. Among 27 Nocardia isolates, 7 species were identified, with the most common species being N. otitidiscaviarum (40.7%). The antimicrobial susceptibility profiles varied between different Nocardia species. Notably, all Nocardia isolates were linezolid susceptible. Majority of Nocardia isolates were collected from a department of respiratory medicine (55.56%) and sputum specimen (44.44%). Pulmonary region was the most involved body site (70.37%), followed by skin (7.4%) and pleural cavity (7.4%). Most patients with Nocardia infection needed combination antibiotic therapy. Two deaths were reported during the treatment period and 24 patients achieved improvement after antibiotic therapy. The clinical manifestations of Nocardia infection and antimicrobial susceptibility profiles varied with diverse Nocardia species. Thus, the accurate identification of these species is crucial for the diagnosis and the selection of antibiotic treatment.