The first case of catheter-related bloodstream infection caused by Nocardia farcinica

Comparative Analysis of CT Findings and Clinical Outcomes in Adult Patients With Disseminated and Localized Pulmonary Nocardiosis

BACKGROUND

Pulmonary nocardiosis is a rare opportunistic infection with occasional systemic dissemination. This study aimed to investigate the computed tomography (CT) findings and prognosis of pulmonary nocardiosis associated with dissemination.

METHODS

We conducted a retrospective analysis of patients diagnosed with pulmonary nocardiosis between March 2001 and September 2023. We reviewed the chest CT findings and categorized them based on the dominant CT findings as consolidation, nodules and/or masses, consolidation with multiple nodules, and nodular bronchiectasis. We compared chest CT findings between localized and disseminated pulmonary nocardiosis and identified significant prognostic factors associated with 12-month mortality using multivariate Cox regression analysis.

RESULTS

Pulmonary nocardiosis was diagnosed in 75 patients, of whom 14 (18.7%) had dissemination, including involvement of the brain in 9 (64.3%) cases, soft tissue in 3 (21.4%) cases and positive blood cultures in 3 (21.4%) cases. Disseminated pulmonary nocardiosis showed a higher frequency of cavitation (64.3% vs. 32.8%, P = 0.029) and pleural effusion (64.3% vs. 29.5%, P = 0.014) compared to localized infection. The 12-month mortality rate was 25.3%. The presence of dissemination was not a significant prognostic factor (hazard ratio [HR], 0.80; confidence interval [CI], 0.23-2.75; P = 0.724). Malignancy (HR, 9.73; CI, 2.32-40.72; P = 0.002), use of steroid medication (HR, 3.72; CI, 1.33-10.38; P = 0.012), and a CT pattern of consolidation with multiple nodules (HR, 4.99; CI, 1.41-17.70; P = 0.013) were associated with higher mortality rates.

CONCLUSION

Pulmonary nocardiosis with dissemination showed more frequent cavitation and pleural effusion compared to cases without dissemination, but dissemination alone did not affect the mortality rate of pulmonary nocardiosis.

Disseminated nocardiosis caused by Nocardia farcinica in a patient with colon cancer: A case report and literature review

RATIONALE

Nocardiosis is an uncommon and potentially life-threatening infection that usually affects immunocompromised hosts. No clinical guidelines have been established for managing this rare disease, and the optimal treatment modality remains unclear. Nocardia farcinica, a relatively infrequent pathogen of nocardiosis, causes a clinically aggressive infection. In addition to our patient data, our search of the literature for patients who presented with empyema caused by N. farcinica will provide fundamental information for optimal treatment modalities.

PATIENT CONCERNS

A 64-year-old man was diagnosed with empyema, 4 days following surgery for sigmoid colon cancer. Brain lesions were evaluated only after N. farcinica was isolated and identified as the causative pathogen through repeated culture tests.

DIAGNOSES

N. farcinica was isolated from the pleural effusion and confirmed as the pathogen through 16S rRNA sequencing.

INTERVENTIONS

The patient was successfully treated with tube thoracotomy, neurosurgical evacuation, and a combination of trimethoprim/sulfamethoxazole plus imipenem. Long-term antibiotic therapy was required to prevent recurrence.

OUTCOMES

Pyothorax showed a good clinical response to antimicrobial therapy and drainage of pleural effusion, whereas brain abscess did not respond to medical therapy and required surgery. The patient eventually recovered and continued chemotherapy as treatment for sigmoid colon cancer.

LESSONS

Although extremely rare, this report demonstrates the importance of considering Nocardia infection as the differential diagnosis in immunocompromised patients who present with empyema. In particular, because of the N. farcinica infection's tendency to spread and the resistance of the organism to antibiotics, aggressive evaluation of metastatic lesions and standardized support from microbiological laboratories are important. Surgery may be required in some patients with brain abscesses to improve the chance of survival.

Nocardia bacteremia: A single-center retrospective review and a systematic review of the literature

OBJECTIVES

Nocardia bacteremia is a rare but severe disease associated with high mortality. This systematic review is the largest and most comprehensive review performed over the past 20 years.

METHODS

A single-center retrospective review of Nocardia bacteremia was performed using hospital microbiology records from January 1, 2010 to December 31, 2017. A systematic literature review was also performed to identify cases of Nocardia bacteremia described in the NCBI PubMed database in English between January 1, 1999 and December 31, 2018.

RESULTS

Four new cases of Nocardia bacteremia are described. The systematic review identified 134 cases with sufficient information available for analysis. Of the total 138 cases, the median age was 58 years (interquartile range (IQR) 44-69 years) and 70% were male. Eighty-one percent were immunocompromised (corticosteroid use (49%), hematological malignancy (20%), solid organ transplant (20%), solid organ malignancy (19%), and hematopoietic stem cell transplantation (15%)) and 29% had endovascular devices. Pulmonary infection was the most common concurrent site of clinical disease (67%). The median incubation time to the detection of Nocardia bacteremia was 4 days (IQR 3-6 days). Blood cultures were the only positive microbiological specimen in 38% of cases. The median total duration of treatment was 75 days (IQR 25-182 days). Thirty-day all-cause mortality was 28% and overall all-cause mortality was 40%.

CONCLUSIONS

Nocardia bacteremia is most frequently identified in immunocompromised patients and those with intravascular devices. Although rare, it represents a serious infection with high associated overall mortality.

Nocardiosis from 1888 to 2017

The genus Nocardia is an aerobic bacterium, Gram-positive and catalase positive that is in Nocardiaceae family. This bacterium first described by Edmond Nocard in 1888 and is not in human commensal bacteria. To date, nocardiosis incidence is increasing due to increase population growth rate, increase in patients with immune disorder diseases and immunocompromised patients. We surveyed taxonomic position, isolation methods, phenotypic and molecular identification at the genus and species levels, antibiogram, treatment and epidemiology in the world from 1888 to 2017.

Creation of an In-House Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Corynebacterineae Database Overcomes Difficulties in Identification of Nocardia farcinica Clinical Isolates

Nocardiosis is a rare disease that is caused by Gram-positive actinobacteria of the Nocardia genus and affects predominantly immunocompromised patients. In its disseminated form, it has a predilection for the central nervous system and is associated with high mortality rates. Therefore, prompt identification of the pathogen is critical. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry is a relatively novel technique used for identification of microorganisms. In this work, an upgraded MALDI-TOF Biotyper database containing Corynebacterineae representatives of strains deposited in the Polish Collection of Microorganisms was created and used for identification of the strain isolated from a nocardial brain abscess, mimicking a brain tumor, in an immunocompetent patient. Testing with the API Coryne system initially incorrectly identified Rhodococcus sp., while chemotaxonomic tests, especially mycolic acid analysis, enabled correct Nocardia identification only at the genus level. Subsequent sequence analysis of 16S rRNA and secA1 genes confirmed the identification. To improve the accuracy of the results, an in-house database was constructed using optimized parameters; with the use of the database, the strain was eventually identified as Nocardia farcinica. Clinical laboratories processing various clinical strains can upgrade a commercial database to improve and to accelerate the results obtained. This is especially important in the case of Nocardia, for which valid microbial diagnosis remains challenging; reference laboratories are often required to identify and to survey these rare actinobacteria.

The first Korean case of disseminated mycetoma caused by Nocardia pseudobrasiliensis in a patient on long-term corticosteroid therapy for the treatment of microscopic polyangiitis

Nocardia pseudobrasiliensis is predominantly associated with invasive infections in immunocompromised patients. We report a case of disseminated mycetoma caused by N. pseudobrasiliensis in a 57-yr-old woman with microscopic polyangiitis, who was treated for 3 months with corticosteroids. The same organism was isolated from mycetoma cultures on the patient's scalp, right arm, and right leg. The phenotypic characteristics of the isolate were consistent with both Nocardia brasiliensis and N. pseudobrasiliensis, i.e., catalase and urease positivity, hydrolysis of esculin, gelatin, casein, hypoxanthine, and tyrosine, but no hydrolysis of xanthine. The isolate was identified as N. pseudobrasiliensis based on 16S rRNA and hsp65 gene sequencing. The patient was treated for 5 days with intravenous ampicillin/sulbactam, at which time both the mycetomas and fever had subsided and discharged on amoxicillin/clavulanate. This case highlights a very rare presentation of mainly cutaneous mycetoma caused by N. pseudobrasiliensis. This is the first reported case of N. pseudobrasiliensis infection in Korea.

Molecular identification and susceptibility pattern of clinical Nocardia species: Emergence of Nocardia crassostreae as an agent of invasive nocardiosis

BACKGROUND

Nocardia species are rare, opportunistic organisms that cause disease in both immunocompetent and immunocompromised individuals.

OBJECTIVE

To investigate the clinical presentations of various Nocardia infections based on the 16S ribosomal RNA gene of the isolate, as well as related risk factors and susceptibility patterns to antimicrobial agents.

METHODS

Thirteen patients with a diagnosis of nocardiosis were included in the present study. Seven Nocardia species were identified by 16S ribosomal RNA. Susceptibility testing was performed using six antimicrobial agents.

RESULTS

Five patients were immunocompromised, and eight were immunocompetent with predisposing factors including cystic fibrosis, tuberculosis and ophthalmic infections. Nocardia caused pulmonary infections in eight patients (61.5%), invasive systemic infections in three patients (23%) and local (ophthalmic) infections in two patients (15.4%). In the patients with pulmonary disease, nocardiosis was caused by six species (Nocardia cyriacigeorgica, Nocardia otitidiscaviarum, Nocardia farcinica, Nocardia carnea, Nocardia testacea and Nocardia asiatica). The seventh species identified in the present study was Nocardia crassostreae.

DISCUSSION

N crassostreae is a multidrug-resistant organism that was reported to be an emerging human pathogen causing invasive nocardiosis in a patient with non-Hodgkin's lymphoma. N farcinica was isolated from blood in a patient with breast cancer. None of the Nocardia isolates were resistant to linezolid. One N otitidiscaviarum isolate was a multidrug-resistant organism. All patients in the present study were treated with the appropriate antibiotics and their condition resolved without further sequelae.

CONCLUSIONS

The present study is the first report on N crassostreae as a human pathogen. The detection of multidrug-resistant species necessitate molecular identification and susceptibility testing, and should be performed for all Nocardia infections. Nocardiosis manifests various clinical features depending on the Nocardia species and underlying conditions.

Actinomyces cardiffensis septicemia: a case report

Actinomyces cardiffensis is an anaerobic, Gram-positive, non-spore-forming rod that was first identified by Hall et al. (Hall V. et al. (2002) J Clin Microbiol 40:3427-31). Here we report a case of bacteremia with liver and lung abscesses associated with A. cardiffensis. A 67-year-old man was hospitalized with fever and headache for 20 days. Blood culture revealed an Actinomyces species, which was ultimately identified as A. cardiffensis by 16S rRNA gene sequencing. A computed tomography scan of his chest showed small abscesses in his lung and liver. After a 3-week course of intravenous ceftriaxone, the patient showed rapid improvement. The patient was transitioned to oral amoxicillin for the remainder of his antibiotic treatment.

Bacteremia caused by Laribacter hongkongensis misidentified as Acinetobacter lwoffii: report of the first case in Korea

Laribacter hongkongensis is an emerging pathogen in patients with community-acquired gastroenteritis and traveler's diarrhea. We herein report a case of L. hongkongensis infection in a 24-yr-old male with liver cirrhosis complicated by Wilson's disease. He was admitted to a hospital with only abdominal distension. On day 6 following admission, he complained of abdominal pain and his body temperature reached 38.6℃. The results of peritoneal fluid evaluation revealed a leukocyte count of 1,180/µL (polymorphonuclear leukocyte 74%). Growth on blood culture was identified as a gram-negative bacillus. The isolate was initially identified as Acinetobacter lwoffii by conventional identification methods in the clinical microbiology laboratory, but was later identified as L. hongkongensis on the basis of molecular identification. The patient was successfully treated with cefotaxime. To the best of our knowledge, this case is the first report of hospital-acquired L. hongkongensis bacteremia with neutrophilic ascites.