Disseminated Nocardia farcinica infection presenting as a paravertebral abscess in a patient with systemic lupus erythematosus

Disseminated Nocardia infections occur particularly in immunosuppressed hosts and are most often due to Nocardia farcinica, Nocardia nova, and Nocardia cyriacigeorgica. Here, we report an unusual case of disseminated N. farcinica infection presenting as a paravertebral abscess in a patient with systemic lupus erythematosus.

Construction of a mutant strain of Nocardia farcinica with mce4A gene deletion and analysis of the role of mce4A gene / 中华微生物学和免疫学杂志

Objective To construct a mutant strain of Nocardia farcinica ( N. farcinica ) IFM10152 with mammalian cell entry 4A gene (mce4A) deletion and to analyze the function of that gene dur-ing infection. -ethods The mutant strain of N. farcinica was constructed through in-frame deletion without antibiotic labeling and verified by PCR and sequencing analysis. To analyze the function of mce4A gene in the interaction between N. farcinica and host cells, in vitro growth experiment, macrophage killing experi-ment using THP-1 ( a human leukemia mononuclear cell line) as the model and adhesion and invasion exper-iments using HeLa cells ( cervical cancer epithelial cells) were carried out. Results The mutant strain with mce4A gene deletion was successfully constructed and named △mce4A. No significant difference in growth rate was observed between the mutant and the wild-type strains. After knocking out the mce4A gene, the ability of N. farcinica to resist macrophage killing was obviously weakened as well as its ability to adhere and invade. Conclusions The mutant strain of N. farcinica with mce4A gene deletion was successfully construc-ted. The mce4A gene might play an important role in the adhesion and invasion of N. farcinica to host cells and its survival in macrophages.

Effects of high glucose and lysophosphatidylcholine (LPC) on RAW264.7 macrophages during No-cardia farcinica infection / 中华微生物学和免疫学杂志

Objective To investigate the effects of high glucose and lysophosphatidylcholine (LPC) on the immune function of in vitro cultured macrophages during Nocardia farcinica infection. Meth-ods RAW264.7 macrophages were cultured in vitro under different conditions as follows: routine culture (control group),50 mmol/L glucose (high glucose group),10 mg/L LPC(LPC groupⅠ),25 mg/L LPC (LPC groupⅡ) and 50 mmol/L glucose+25 mg/L LPC(high glucose and LPC group). The activity of mac-rophages in each group was tested after 6,12,24 and 36 h of culture. After 24 h of culture, macrophages were collected from every group and co-cultured with Nocardia farcinica. Dynamic phagocytosis rates were detected at 1,2,3,4,5 and 6 h after co-culture. Toxic effects of Nocardia farcinica on macrophages and concentrations of IL-10 and TNF-α were measured at 1,3 and 6 h after co-culture. Results Macrophages in all four experimental groups showed decreased activity as compared with those in the control group (P<0.01). Phagocytosis of Nocardia farcinica by macrophages was also reduced by high glucose and LPC. Phagocytosis rates of high glucose group and LPC groupⅡ at 1 and 2 h,LPC groupⅠat 1,2 and 3 h,and high glucose and LPC group at 1,2,3 and 4 h after co-culture were significantly lower than that of the con-trol group (P<0.05 or P<0.01). Compared with the control group, significantly reduced toxic effects on macrophages caused by Nocardia farcinica was observed in the experimental groups (P<0.05 or P<0.01). Compared with the control group,LPC groupsⅠand Ⅱ and high glucose and LPC group had decreased se-cretion of IL-10 at 3 h,and high glucose group and LPC groupⅠhad decreased secretion of TNF-α at 1 h(P<0.05). Conclusion Culture macrophages under the conditions of high glucose and LPC would reduce their activity and impair their ability to phagocytose Nocardia farcinica. Moreover, high glucose and LPC might have impacts on the toxic effects of Nocardia farcinica on macrophages and the secretion of IL-10 and TNF-α.

A fatal case of severe Nocardia farcinica pneumonia and literature review of 25 cases / 中国感染控制杂志

Nocardia is a genus of gram-positive,weakly acid-fast,filamentous aerobic actinomycetes,which mainly causes infection in immunocompromised persons. We reported a successfully treated fatal case of severe pneumonia caused by Nocardia farcinica in a hospital,then reviewed 25 domestic and abroad case reports about nocardiosis combined with severe pneumonia occurred since 2006,so as to improve health care workers'cognition on clinical manifestations,image features,pathogenic characteristics,and diagnostic and treatment schemes of se-vere pneumonia caused by Nocardia farcinica.

Primary Cutaneous Nocardiosis Caused by Nocardia farcinica / 대한피부과학회지

The Nocardia species are aerobic Gram-positive filamentous bacteria found worldwide in soil and decaying organic plant matter. Primary cutaneous nocardiosis is a rare entity and most commonly caused by Nocardia brasiliensis (N. brasiliensis). However, it can rarely be caused by N. farcinica, which is recognized as a human pathogen. Here we report a case of a 54-year-old female patient who presented with erythematous nodules on her abdomen for 1 week. She had been treated with methotrexate and prednisolone due to systemic lupus erythematosus and rheumatoid arthritis. By bacterial culture and 16S ribosomal RNA gene sequencing, the patient was diagnosed with a primary cutaneous nocardiosis caused by N. farcinica, which has not previously been reported in the Korean dermatological literature.

A fatal case of empyema thoracis by Nocardia farcinica in an immunocompromised patient.

Empyema thoracis by Nocardia farcinica infection is uncommon. Here we report a rare and fatal infection in a 27-year-old HIV- seropositive male who presented with cough, expectoration, and breathlessness. Nocardia farcinica was isolated from sputum and pus from the pleural cavity. Confirmation of the isolate and minimum inhibitory concentrations (MIC) for various antibiotics was done at the Aerobic Actinomycetes Reference Laboratory, Centres for Disease Control and Prevention (CDC), Atlanta. Patient was treated with suitable antibiotics and antiretroviral drugs in spite of which he eventually succumbed to the disease.

The First Case of Catheter-related Bloodstream Infection Caused by Nocardia farcinica

Nocardia farcinica is an emerging pathogen in immunocompromised hosts. Even though several species of Nocardia have been reported as causative pathogens of catheter-related blood stream infections (CRBSI), CRBSI caused by N. farcinica has not been reported. A 70-yr-old man with a tunneled central venous catheter (CVC) for home parenteral nutrition was admitted with fever for two days. Norcardia species was isolated from the blood through CVC and peripheral bloods and identified to N. farcinica by 16S rRNA and rpoB gene sequence analyses. This report emphasizes the rapid and correct identification of causative agents in infectious diseases in the selection of antimicrobial agents and the consideration of catheter removal.

Pulmonary nocardiosis due to nocardia farcinica in a renal transplant recipient.

Nocardia farcinica is an infrequent cause of nocardiosis among the renal transplant recipients and it has not been reported so far from India. We report a case of pulmonary nocardiosis due to N. farcinica in a 32-year-old woman with hypothyroidism and post-renal transplant status, currently on immunosuppressive therapy (prednisolone, azathioprine and tacrolimus). The N. farcinica isolate was susceptible to trimethoprim-sulfamethoxazole (TMP-SMZ), linezolid, imipenem, gentamicin but resistant to ceftriaxone, ciprofloxacin, tobramycin, erythromycin, amoxycillin-clavulanic acid and tetracycline. Treatment with TMP-SMZ and linezolid resulted in marked clinico-radiological improvement but after two weeks both of the drugs had to be stopped due to severe pancytopenia as adverse effect of their use. Currently, the patient is on imipenem and remains stable after four weeks of treatment. In N. farcinica infections, multi antibiotic resistance and toxicity of some specific drugs enhances the risk of therapeutic failure in renal transplant recipients.

A Case of Nocardia farcinica Brain Abscess in the Patient Receiving Steroid Treatment

Nocardiosis occurs mostly in the immunocompromised patients. N. farcinica is known to have resistance to some antibiotics and significant increase in morbidity and mortality in patients requiring long-term treatment. Nocardia farcinica infection, especially brain abscess, has not been reported in Korea. Here, we report a case of N. farcinica brain abscess in a patient receiving steroid treatment. The patient was a 64 year-old male with gouty arthritis. He received steroid for more than two months, because of allopurinol-hypersensitivity syndrome with skin rash. After three months of steroid therapy, he visited other hospital with mild fever and left thigh pain and was diagnosed of intramuscular abscess due to gram positive bacilli. One month later, he visited our hospital with right side weakness and was diagnosed as brain abscess. The causative organism turned out to be N. farcinica, which was confirmed by means of 16S rRNA sequencing. Antibiotics were selected by E-test results and treatment was successful

A Case of Nocardia farcinica Brain Abscess in the Patient Receiving Steroid Treatment

Nocardiosis occurs mostly in the immunocompromised patients. N. farcinica is known to have resistance to some antibiotics and significant increase in morbidity and mortality in patients requiring long-term treatment. Nocardia farcinica infection, especially brain abscess, has not been reported in Korea. Here, we report a case of N. farcinica brain abscess in a patient receiving steroid treatment. The patient was a 64 year-old male with gouty arthritis. He received steroid for more than two months, because of allopurinol-hypersensitivity syndrome with skin rash. After three months of steroid therapy, he visited other hospital with mild fever and left thigh pain and was diagnosed of intramuscular abscess due to gram positive bacilli. One month later, he visited our hospital with right side weakness and was diagnosed as brain abscess. The causative organism turned out to be N. farcinica, which was confirmed by means of 16S rRNA sequencing. Antibiotics were selected by E-test results and treatment was successful