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Nocardia is widely distributed in the natural environment and typically cause opportunistic infections. However, it is important to note that the pathogenicity of different Nocardia species may vary significantly. Here we reported the first case of brain abscess caused by Nocardia beijingensis (N. beijingensis) infection in China. A 70-year-old male immunocompetent individual came to our hospital for treatment due to headache. After examination, it was found that he had a brain abscess caused by N. beijingensis. By utilizing a combination of surgical intervention and antibiotic therapy, the patient ultimately achieved full recovery. In addition, we isolated this strain and displayed its ultrastructure through scanning electron microscopy. The phylogenetic tree was analyzed by 16 S rRNA sequence. A literature review of N. beijingensis infections in all immunocompetent and immunocompromised patients was presented. It highlighted that abscess formation appears to be a common manifestation of N. beijingensis infection, and N. beijingensis has become an emerging pathogen in immunocompetent individuals. [ABSTRACT FROM AUTHOR]

A study published in the journal Transplant Infectious Disease examines the risk of opportunistic infections after solid organ transplantation in patients with a sulfonamide allergy label. The study found that the presence of a sulfonamide allergy label influenced prescribing practices, with a decreased use of trimethoprim/sulfamethoxazole (TMP-SMX) and an increased use of alternative prophylactic agents. While the sulfonamide allergy label was not associated with an increased risk of Pneumocystis jirovecii infection, it was associated with a significantly increased risk of Toxoplasma and Nocardia infections. The study highlights the importance of managing SOT recipients with sulfonamide allergy labels and suggests that a careful history is essential in guiding decision-making. The article discusses the use of trimethoprim/sulfamethoxazole (TMP-SMX) as a prophylactic agent in solid organ transplant (SOT) recipients and the challenges associated with sulfonamide allergy labels. The authors highlight the importance of reassessing sulfonamide allergy labels in SOT recipients and suggest the use of direct oral TMP-SMX challenge as a safe and easier alternative to desensitization. They also emphasize the need for a simple and practical sulfonamide allergy clinical decision rule to enable point-of-care risk assessment and direct oral TMP-SMX challenge. The article concludes by emphasizing the importance of using TMP-SMX in eligible SOT recipients to prevent opportunistic infections. [Extracted from the article]

Background Methods Results Conclusion While a penicillin allergy label has been linked to various negative clinical outcomes, limited studies have specifically characterized the implication of sulfonamide allergy labels (SAL) on clinical outcomes. We examined the impact of SAL on clinical outcomes of solid organ transplant recipients.In this retrospective matched cohort study, we utilized the TriNetX US collaborative Network, a multicenter de‐identified US database, and identified solid organ transplant recipients with and without SAL. The 1‐year probability of developing Pneumocystis jirovecii pneumonia (PJP), toxoplasmosis, and nocardiosis was estimated and contrasted between the two study groups. The hazard ratio (HR) and the 95% confidence interval (CI) quantified the strength and direction of the association between SAL and these outcomes.When comparing 1571 solid organ transplant recipients with SAL to an equal number of matched controls, patients with SAL had a higher probability of developing nocardiosis (HR 3.85; 95% CI, 1.44–10.30; p = .004; corrected p = .04), and toxoplasmosis (HR, 1.87; 95% CI, 1.10–3.17; p = .019; corrected p = .19), but no difference in the risk of developing PJP (HR, 1.64; 95% CI, 0.68–3.95; p = .27). There was no mortality difference (HR, 1.31; 95% CI, 0.99–1.75; p = .061; corrected p = .6). SAL influenced antibiotic prescription with overutilization of dapsone, atovaquone, and pentamidine and underutilization of trimethoprim and sulfamethoxazole.SAL is associated with an increased risk of opportunistic infections following solid organ transplantation. Measures to evaluate and de‐label sulfonamide allergy prior to transplantation or desensitizing shortly after transplantation are advisable. [ABSTRACT FROM AUTHOR]

We reviewed invasive Nocardia infections in 3 noncontiguous geographic areas in the United States during 2011-2018. Among 268 patients with invasive nocardiosis, 48.2% were from Minnesota, 32.4% from Arizona, and 19.4% from Florida. Predominant species were N. nova complex in Minnesota (33.4%), N. cyriacigeorgica in Arizona (41.4%), and N. brasiliensis in Florida (17.3%). Transplant recipients accounted for 82/268 (30.6%) patients overall: 14 (10.9%) in Minnesota, 35 (40.2%) in Arizona, and 33 (63.5%) in Florida. Manifestations included isolated pulmonary nocardiosis among 73.2% of transplant and 84.4% of non-transplant patients and central nervous system involvement among 12.2% of transplant and 3.2% of non-transplant patients. N. farcinica (20.7%) and N. cyriacigeorgica (19.5%) were the most common isolates among transplant recipients and N. cyriacigeorgica (38.0%), N. nova complex (23.7%), and N. farcinica (16.1%) among non-transplant patients. Overall antimicrobial susceptibilities were similar across the 3 study sites. [ABSTRACT FROM AUTHOR]

Objective To analyze the clinical characteristics of pulmonary tuberculosis patients complicated with infection of Nocardia farcinica aiming to improve the diagnosis and treatment the disease. Methods The clinical data of 22 cases of pulmonary tuberculosis complicated with Nocardia farcinica infection admitted to Guangzhou Chest Hospital from June 2020 to December 2023 were collected and the clinical manifestations, imaging, laboratory tests, treatment process, and disease outcomes were retrospectively analyzed. Results Among the 22 patients, there were 13 males and 9 females, aged 20 - 86 years, with a median age of 52 years. Common clinical manifestations included cough (22/22), sputum (21/22), and underlying diseases (13/22) . One case was positive for cerebrospinal fluid culture, and 21 cases were positive for sputum culture. The culture period was 5 - 26 days, with a median culture period of 18 days. The imaging manifestations were mainly plaques, plaques and cavities, and the lesions were spread in both lungs (17/22) and cavities (11/22) . After anti-tuberculosis treatment, the absorption of lung lesions in some patients was poor, and the absorption of the lesions was improved after anti-nocardia treatment. 8 cases were cured, 13 cases were improved and 1 case died. Conclusion The clinical symptoms of patients with pulmonary tuberculosis complicated with Nocardia farcinica were atypical, the culture period of Nocardia was long, and the imaging manifestations were similar to pulmonary tuberculosis, which is prone to misdiagnosis and missed diagnosis. For patients with poor response to anti-tuberculosis treatment and slow lesion absorption, the possibility of a concurrent Nocardia infection should be considered. [ABSTRACT FROM AUTHOR]

The article focuses on antiviral resistance in influenza viruses, particularly targeting matrix protein 2 (M2), neuraminidase (NA), and cap-dependent endonuclease (CEN) through direct-acting antivirals. Topics include the emergence of resistance mutations like H275Y in NA inhibitors such as oseltamivir, the global surveillance efforts by WHO-GISRS to monitor resistance.

Nocardiosis, caused by Nocardia seriolae, has been a prominent disease in Southeast Asian aquaculture in the last three decades. This granulomatous disease reported in various fish species is responsible for significant economic losses. This study investigated the pathogenicity of N. seriolae in three cultured species in Taiwan: Nile tilapia (omnivore), milkfish (herbivore) and Asian seabass (carnivore). Administration of an infective dose of 1 × 106 CFU/ fish in tilapia, seabass and milkfish demonstrated mortalities of 100%, 90% and 75%, respectively. Additionally, clinical signs namely, granuloma and lesions displayed varying intensities between the groups and pathological scores. Polymerase chain reaction (PCR) amplification specific for N. seriolae was confirmed to be positive (432 bp) using NS1/NG1 primers. Post‐mortem lesions revealed the absence of granulomas in tilapia and milkfish and their presence in the seabass. Interestingly, the gut in tilapia showed an influx of eosinophils suggesting its role during the acute stages of infection. However, post‐challenge, surviving milkfish exhibited granulomatous formations, while surviving seabass progressed toward healing and tissue repair within sampled tissues. Overall, in conclusion, these results demonstrate the versatility in the immunological ability of individual Perciformes to contain this pathogen as a crucial factor that influences its degree of susceptibility. [ABSTRACT FROM AUTHOR]

Purpose: Anti-granulocyte-macrophage colony-stimulating factor autoantibodies (anti-GM-CSF Abs) are implicated in the pathogenesis of Cryptococcus gattii (C. gattii) infection and pulmonary alveolar proteinosis (PAP). Their presence has also been noted in nocardiosis cases, particularly those with disseminated disease. This study delineates a case series characterizing clinical features and specificity of anti-GM-CSF Abs in nocardiosis patients. Methods: In this study, eight patients were recruited to determine the presence or absence of anti-GM-CSF Abs. In addition to the detailed description of the clinical course, we thoroughly investigated the autoantibodies regarding the characteristics, isotypes, subclasses, titers, and neutralizing capacities by utilizing the plasma samples from patients. Results: Of eight patients, five tested positive for anti-GM-CSF Abs, all with central nervous system (CNS) involvement; patients negative for these antibodies did not develop CNS nocardiosis. Distinct from previously documented cases, none of our patients with anti-GM-CSF Abs exhibited PAP symptoms. The titer and neutralizing activity of anti-GM-CSF Abs in our cohort did not significantly deviate from those found in C. gattii cryptococcosis and PAP patients. Uniquely, one individual (Patient 3) showed a minimal titer and neutralizing action of anti-GM-CSF Abs, with no relation to disease severity. Moreover, IgM autoantibodies were notably present in all CNS nocardiosis cases investigated. Conclusion: The presence of anti-GM-CSF Abs suggests an intrinsic immunodeficiency predisposing individuals toward CNS nocardiosis. The presence of anti-GM-CSF Abs helps to elucidate vulnerability to CNS nocardiosis, even with low titer of autoantibodies. Consequently, systematic screening for anti-GM-CSF Abs should be considered a crucial diagnostic step for nocardiosis patients. [ABSTRACT FROM AUTHOR]

Nocardiosis is an opportunistic infection that affects both immunocompromised as well as immunocompetent patients. The main infections occur as soft tissue and lung infections although they might disseminate to various organs. This is a case study aimed to reflect the severity of the disease and the patient’s risk factors associated with the infection. A sputum sample was collected from tuberculosis (TB) suspects for culture. Nocardia-like colonies were isolated, purified, and sent to BGI Company (Hongkong, China). Standard forward sequencing of 16S rRNA was done by ABI Genetic Analyzer (Applied Biosystems). Sequence alignment and nucleotide basic local alignment search tool (BLAST) were done using National Center for Bioinformatics (NCBI) Nucleotide BLAST. Biochemical identification to the colonies was done using an automation system (BD Phoenix™) to confirm the identification. Nocardia paucivorans was identified from the TB suspect. Risk factors were identified as extensive contact to dust, absence of primary care units with complete facilities, and old age. Since the infection of the lungs caused by Nocardia might be similar to pulmonary TB, this case report highlights the importance of accurate diagnosis and identification procedures to differentiate between the two.

Abstract Background Nocardia species can affect both immunocompetent and immunocompromised people. Method This retrospective study, from 2009 to 2022, aims to compare the survival analyses of pulmonary nocardiosis in AIDS and non-AIDS patients in northeastern Thailand. Results A total of 215 culture-confirmed cases of pulmonary nocardiosis: 97 with AIDS and 118 without AIDS. The median CD4 count of AIDS patients was 11 cells/µL (range: 1–198), and 33% had concurrent opportunistic infections. 63.6% of 118 non-AIDS patients received immunosuppressive medications, 28.8% had comorbidities, and 7.6% had no coexisting conditions. Disseminated nocardiosis and pleural effusion were more prevalent among AIDS patients, whereas non-AIDS patients revealed more shock and respiratory failure. One hundred-fifty patients underwent brain imaging; 15 (10%) had brain abscesses. Patients with pulmonary nocardiosis have overall 30-day and 1-year mortality rates of 38.5% (95% CI: 32.3%, 45.4%) and 52.1% (95% CI: 45.6%, 58.9%), respectively. The Cox survival analysis showed that AIDS patients with disseminated nocardiosis had a 7.93-fold (95% CI: 2.61–24.02, p

Nocardiosis is an infectious disease caused by Nocardia spp., mainly affecting immunocompromised hosts. Nocardia infection is not common; especially Nocardia wallacei infection is even rarer. The patient, female, 61 years old, farmer, has been working in the field for a long time and has normal immune function. Her main clinical manifestation was persistent back pain. Chest-enhanced computed tomography showed pulmonary inflammation. Rare pathogen Nocardia wallacei was detected in alveolar lavage fluid using matrix-assisted laser destructive ionization time-of-flight mass spectrometry. She received treatment with linezolid and was discharged after her condition improved.

Background: Nocardia species can affect both immunocompetent and immunocompromised people. Method: This retrospective study, from 2009 to 2022, aims to compare the survival analyses of pulmonary nocardiosis in AIDS and non-AIDS patients in northeastern Thailand. Results: A total of 215 culture-confirmed cases of pulmonary nocardiosis: 97 with AIDS and 118 without AIDS. The median CD4 count of AIDS patients was 11 cells/µL (range: 1–198), and 33% had concurrent opportunistic infections. 63.6% of 118 non-AIDS patients received immunosuppressive medications, 28.8% had comorbidities, and 7.6% had no coexisting conditions. Disseminated nocardiosis and pleural effusion were more prevalent among AIDS patients, whereas non-AIDS patients revealed more shock and respiratory failure. One hundred-fifty patients underwent brain imaging; 15 (10%) had brain abscesses. Patients with pulmonary nocardiosis have overall 30-day and 1-year mortality rates of 38.5% (95% CI: 32.3%, 45.4%) and 52.1% (95% CI: 45.6%, 58.9%), respectively. The Cox survival analysis showed that AIDS patients with disseminated nocardiosis had a 7.93-fold (95% CI: 2.61–24.02, p < 0.001) increased risk of death within 30 days compared to non-AIDS patients when considering variables such as age, Charlson comorbidity index, concurrent opportunistic infections, duration of illness, shock, respiratory failure, multi-lobar pneumonia, lung abscesses, and combination antibiotic therapy. While AIDS and pulmonary nocardiosis had a tendency to die within 30 days (2.09 (95% CI, 0.74–5.87, p = 0.162)). Conclusion: AIDS with pulmonary nocardiosis, particularly disseminated disease, is a serious opportunistic infection. Early diagnosis and empiric treatment with a multidrug regimen may be the most appropriate approach in a resource-limited setting. [ABSTRACT FROM AUTHOR]

Background: Nocardia is an ubiquitous soil organism. As an opportunistic pathogen, inhalation and skin inoculation are the most common routes of infection. Lungs and skin are the most frequent sites of nocardiosis. Testis is a highly unusual location for nocardiosis. Case presentation: We report the case of an immunocompromised 75-year-old-man admitted for fever of unknown origin. He presented with skin lesions after gardening and was first suspected of Mediterranean spotted fever, but he did not respond to doxycycline. Then, physical examination revealed new left scrotal swelling that was compatible with a diagnosis of epididymo-orchitis. The patient's condition did not improve despite empirical antibiotic treatment with the onset of necrotic scrotal abscesses requiring surgery. Nocardia brasiliensis yielded from the removed testis culture. High-dose trimethoprim-sulfamethoxazole and ceftriaxone were started. Multiple micro-abscesses were found in the brain and spinal cord on imaging studies. After 6 weeks of dual antibiotic therapy for disseminated nocardiosis, slight regression of the brain abscesses was observed. The patient was discharged after a 6-month course of antibiotics and remained relapse-free at that time of writing these lines. Trimethoprim-sulfamethoxazole alone is meant to be pursued for 6 months thereafter. We undertook a literature review on previously reported cases of genitourinary and urological nocardiosis; to date, only 36 cases have been published with predominately involvement of kidney, prostate and testis. Conclusions: To the best of our knowledge, this is the first case of Nocardia brasiliensis simultaneously infecting skin, testis, brain and spinal cord in an immunocompromised patient. Knowledge on uncommon forms of nocardiosis remains scarce. This case report highlights the difficulty of diagnosing atypical nocardiosis and the importance of prompt bacteriological sampling in case of empirical antibiotics failure. [ABSTRACT FROM AUTHOR]

Nocardiosis demonstrates a temporal categorization that includes acute, subacute, and chronic stages alongside distinct typical localizations such as pulmonary, cutaneous, and disseminated forms. Disseminated nocardiosis, commonly caused by Nocardia asteroides, N. brasiliensis, and N. farcinica, continues to result in substantial morbidity and mortality. Herein, we report a life-threatening disseminated nocardiosis caused by Nocardia otitidiscaviarum in a patient with minimal change disease. This study emphasizes the difficulty in the diagnosis and treatment of unknown infections in clinical settings and highlights the important role played by laboratories in solving infectious diseases caused by rare pathogens. [ABSTRACT FROM AUTHOR]

Background Nocardiosis, a bacterial opportunistic infection caused by Nocardia spp, has recently been reported in patients with anti–granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies, but insufficient data are available about disease presentation, outcomes, and occurrence of autoimmune pulmonary alveolar proteinosis (aPAP) in this population. Methods We performed a prospective, multicenter, nationwide study in France and included patients with a Nocardia infection who had anti-GM-CSF autoantibodies. We describe their clinical, microbiological, and radiological characteristics, and their outcome at 1 year of follow-up. Results Twenty patients (18 [90%] male) were included, with a median age of 69 (interquartile range, 44–75) years. The organs most frequently involved were the brain (14/20 [70%]) and the lung (12/20 [60%]). Half of the infections were disseminated (10/20 [50%]). Nocardia identification was predominantly made in abscess fluid (17/20 [85%]), among which 10 (59%) were brain abscesses. The 1-year all-cause mortality was 5% (1/20), and only 1 case of aPAP (1/20 [5%]) occurred during the follow-up period. Conclusions Nocardiosis with anti-GM-CSF autoantibodies is associated with a low mortality rate despite a high incidence of brain involvement. Although the occurrence of aPAP was infrequent during the 1-year follow-up period, long-term clinical data are needed to fully understand the potential relationship between nocardiosis, anti-GM-CSF autoantibodies, and aPAP. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Ochrobactrum anthropi (O. anthropi), a rare opportunistic pathogen, caused sepsis in a malnourished 15‐month‐old African child. Early detection and appropriate antibiotics led to full recovery, highlighting the importance of robust surveillance for emerging pathogens in vulnerable populations. While rarely causing infections, O. anthropi, a non‐fermenting, obligately aerobic, flagellated gram‐negative bacillus, demonstrates oxidase positivity and indole negativity. Traditionally, Ochrobactrum spp is considered a low threat due to its environmental abundance and mild virulence. It is, however, a multidrug‐resistant bacteria known for causing opportunistic infections in humans. O. anthropi is typically associated with catheter‐related bloodstream infections. The first documented case was in 1998; most cases have been reported in developed countries. We present a case of O. anthropi sepsis in a malnourished child in sub‐Saharan Africa. We report a case involving a 15‐month‐old African female who presented with symptoms and signs of protein‐energy malnutrition and sepsis. The blood culture revealed O.anthropi. We treated the child with the empirical first‐line antibiotics per the national guidelines, intravenous ampicillin and gentamicin for a week, and the child fully recovered. This report describes a rare case of O. anthropi sepsis with malnutrition in an African female child. O. anthropi is an emerging pathogen causing opportunistic infections in both immunocompetent and immunocompromised patients. We report that early bacterial detection, appropriate antibiotic susceptibility and antimicrobial management based on local antibiogram data may be essential for excellent patient outcomes. Additionally, we recommend more robust surveillance to detect such rare emerging pathogens. [ABSTRACT FROM AUTHOR]

Nocardia is a gram-positive bacillus with the microscopic appearance of branching hyphae and is mainly distributed in the soil. Nocardiosis more frequently occurs in immunosuppressed patients. Since nocardiosis has a high mortality rate, immediate diagnosis and treatment are needed. We report the first case of pulmonary nocardiosis caused by Nocardia pseudobrasiliensis after liver transplantation. A 58-year-old woman underwent living-donor transplantation for primary biliary cholangitis. Seven months after transplantation, she came to our hospital complaining of fever and anorexia. Computed tomography of the lungs showed a 45 mm large nodule affecting the upper lobe of the left lung. We started administering empiric antibiotics and tapering immunosuppression, but the patient's condition gradually worsened, and lung lesions increased. On the fifth day after hospitalization, bacteria developed from sputum cultures were identified as N. pseudobrasiliensis by matrix-assisted laser desorption ionization time of flight mass spectrometry. We started treatment with trimethoprim-sulfamethoxazole. The patient's clinical symptoms and laboratory data improved quickly. After one month of hospitalization, this patient was discharged. Then, the lung lesion almost vanished. Ten years after her transplant, the patient is alive with a well-functioning graft. [ABSTRACT FROM AUTHOR]

Solid organ transplant recipients (SOTRs) are at an increased risk of nocardiosis, a rare but life-threatening opportunistic infection. Universal PCP prophylaxis with trimethoprim–sulfamethoxazole (TMP-SMX) is used at our center, which is active in vitro against most species of the Nocardia genus and may have a role in preventing early infections. This is a single-center retrospective cohort study of nocardiosis in adult SOTRs at a large transplant center between January 2012 and June 2022, with comprehensive review of literature. Out of 6179 consecutive cases, 13 (0.2%) were diagnosed with nocardiosis. The patients were predominantly male (76.9%) and kidney transplant recipients (62%). Infection was diagnosed at median of 8.8 months (range, 3.7–98) after transplant. Patients were followed for a median of 457 days (range 8–3367). Overall mortality within one year after diagnosis was 46% (6/13), of which 17% (1/6) of deaths was attributable to Nocardia infection. No recurrence was reported. Nocardia infections were noted in a small proportion of our SOTRs and carried significant morbidity and mortality. TMP-SMX prophylaxis may be protective in some cases given low incidence of cases. [ABSTRACT FROM AUTHOR]

Background: In China, due to the large population, infections caused by Nocardia may not be as rare. Unfortunately, there is still inadequate knowledge of the clinical impact caused by Nocardia. This study aimed to compare the clinical characteristics and treatment of localized and disseminated nocardiosis. Methods: The clinical and microbiological data of patients diagnosed with nocardiosis in a tertiary hospital in Beijing from July 2011 to July 2021 were collected and retrospectively analyzed. Results: Among the 54 nocardiosis cases, 34 cases were in the localized infection group, while 20 cases in the disseminated infection group. The proportion of patients with chronic structural lung disease was higher in the localized group (P=0.010). In contrast, patients with disseminated infections were more prone to receive long-term glucocorticoids and/or immunosuppressants (P=0.027). Pulmonary nodules were prominent features of imaging changes in patients with disseminated infections (P=0.027) whereas bronchial dilatation was more common in patients with localized infections (P=0.025). In addition, the disseminated group had longer average hospitalization days relative to the localized group (P=0.016), but there was no significant difference in mortality between them (P=0.942). Conclusion: There were differences in the clinical profiles between patients with localized and disseminated nocardiosis in terms of clinical presentation, infection site, radiological features, treatment, and prognosis. These findings may provide references for the management and treatment of patients with nocardiosis. [ABSTRACT FROM AUTHOR]

Infections that are unusually severe or caused by opportunistic pathogens are a hallmark of primary immunodeficiency (PID). Anti-cytokine autoantibodies (ACA) are an emerging cause of acquired immunodeficiency mimicking PID. Nocardia spp. are Gram-positive bacteria generally inducing disseminated infections in immunocompromised patients, but seldom also occurring in apparently immunocompetent hosts. Anti-GM-CSF autoantibodies are associated with autoimmune pulmonary alveolar proteinosis (PAP). In those patients, an increased incidence of disseminated nocardiosis and cryptococcosis has been observed. It is unclear whether the PAP or the autoantibodies predispose to the infection. We report an apparently immunocompetent woman presenting with disseminated nocardiosis without any evidence of PAP. Clinical data and radiological images were retrospectively collected. Lymphocyte populations were analyzed by flow cytometry. Anti-GM-CSF autoantibodies were measured by ELISA. A 55-year-old otherwise healthy woman presented with cerebral and pulmonary abscesses. Personal and familial history of infections or autoimmunity were negative. After extensive examinations, a final diagnosis of disseminated nocardiosis was made. Immunologic investigations including neutrophilic function and IFN-γ/IL-12 circuitry failed to identify a PID. Whole-exome sequencing did not find pathogenic variants associated with immunodeficiency. Serum anti-GM-CSF autoantibodies were positive. There were no clinical or instrumental signs of PAP. Trimethoprim-sulfamethoxazole and imipenem were administered, with progressive improvement and recovery of the infectious complication. We identified anti-GM-CSF autoantibodies as the cause of disseminated nocardiosis in a previously healthy and apparently immunocompetent adult. This case emphasizes the importance of including ACA in the differential diagnosis of PID, especially in previously healthy adults. Importantly, anti-GM-CSF autoantibodies can present with disseminated nocardiosis without PAP. [ABSTRACT FROM AUTHOR]

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Nocardia seriolae is the primary pathogen causing nocardiosis in various fish species, leads to significant economic losses in the aquaculture industry. In this study, 10 bacterial strains isolated from Micropterus salmoides and Channa argus infected with nocardiosis, were identified as N. seriolae by physiological and biochemical identification, as well as 16S rDNA sequencing. Moreover, the key virulence-related genes such as ESX-1, T7SS-2, T7SS-3, EspG1, sodC, sod2 and ESAT6 were all positive, and showing high homology among different strains. Pathogenicity testing revealed mortality rates ranging from 70 to 100%, accompanied by the presence of white nodules in the viscera of deceased fish. The drug sensitivity test demonstrated that LY21811, the most lethal strain, exhibited high sensitivity to nine types of antibiotics, including azithromycin, doxycycline, florfenicol and compound sulfamethoxazole, yet showed complete resistance to ß-lactam antibiotics. Additionally, the tannic acid also demonstrated potent inhibitory effects against LY21811, with a minimum inhibitory concentration of 0.0625 mg/mL. These results showed that N. seriolae originated from M. salmoides and C. argus in Zhejiang Province were highly conserved, demonstrating a high homogeneity in genetic characteristics, pathogenicity and antimicrobial susceptibilities. These results provide a foundation for further research on the pathogenic characteristics and disease prevention of N. seriolae infections. [ABSTRACT FROM AUTHOR]

Nocardia farcinica is rarely isolated from clinical specimens, and it is a more virulent strain than other types of Nocardia. In this report, we evaluated a rare case of pleural empyema and pneumonia caused by Nocardia farcinica in a patient who had risk factors such as long-term use of corticosteroids, chronic respiratory disease, and a brain tumor. The distinction of N. farcinica from other Nocardia species is important because N. farcinica is more virulent and highly resistant, especially to broad-spectrum cephalosporins, which can make treatment difficult. In conclusion, in the presence of nonspecific physical examination and radiographic findings in patients using immunosuppressives and having comorbid diseases, atypical causative agents such as Nocardia infection should be considered in the differential diagnosis. [ABSTRACT FROM AUTHOR]

Background Nocardia tends to cause infection in immunocompromised patients or those with chronic pulmonary disease. Nocardia is known to recur, prompting the practice of secondary prophylaxis in patients perceived at high risk. However, few data exist regarding the epidemiology of recurrent nocardiosis or the effectiveness of secondary prophylaxis. Methods We performed a multicenter, retrospective cohort study of adults diagnosed with nocardiosis from November 2011 to April 2022, including patients who completed primary treatment and had at least 30 days of posttreatment follow-up. Propensity score matching was used to analyze the effect of secondary prophylaxis on Nocardia recurrence. Results Fifteen of 303 (5.0%) patients developed recurrent nocardiosis after primary treatment. Most recurrences were diagnosed either within 60 days (N = 6/15, 40.0%) or between 2 to 3 years (N = 4/15, 26.7%). Patients with primary disseminated infection tended to recur within 1 year, whereas later recurrences were often nondisseminated pulmonary infection. Seventy-eight (25.7%) patients were prescribed secondary prophylaxis, mostly trimethoprim-sulfamethoxazole (N = 67/78). After propensity-matching, secondary prophylaxis was not associated with reduced risk of recurrence (hazard ratio, 0.96; 95% confidence interval,.24–3.83), including in multiple subgroups. Eight (53.3%) patients with recurrent nocardiosis required hospitalization and no patients died from recurrent infection. Conclusions Recurrent nocardiosis tends to occur either within months because of the same Nocardia species or after several years with a new species. Although we did not find evidence for the effectiveness of secondary prophylaxis, the confidence intervals were wide. However, outcomes of recurrent nocardiosis are generally favorable and may not justify long-term antibiotic prophylaxis for this indication alone. [ABSTRACT FROM AUTHOR]

Copyright of Epidemiological Review / Przegląd Epidemiologiczny is the property of National Institute of Public Health - National Institute of Hygiene and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Nocardiosis is primarily an opportunistic infection affecting immunocompromised individuals, with a predilection for the lungs, brain, or skin in those with compromised immune function. Granulomatous hepatitis caused by Nocardia is a rare clinical manifestation. This study aims to provide a systematic overview of the clinical features of Nocardiosis caused by Nocardia farcinica, enhancing our understanding of this disease. Methods: We report a case of a 75-year-old male with no underlying diseases presenting with a history of "recurrent fever for more than 4 months", along with fatigue, poor appetite, and pleural and abdominal effusion. Despite treatment at multiple hospitals, the patient showed little improvement. Chest CT revealed chronic inflammation, small nodules, bilateral pleural effusion, and pleural thickening. Abdominal CT indicated multiple low-density lesions in the liver, multiple small calcifications, and abdominal effusion. Results: Liver biopsy suggested inflammatory changes, with focal granuloma formation. Metagenomic next-generation sequencing (mNGS) of liver tissue indicated Nocardia farcinica, leading to the final diagnosis of disseminated Nocardia farcinica granulomatous hepatitis. Conclusion: Nocardia infection is a rare disease primarily observed in immunocompromised patients but can also occur in those with normal immune function. The clinical and radiological features lack specificity; however, the utilization of mNGS technology enables rapid identification of the pathogenic microorganism. Nocardia farcinica is generally susceptible to sulfonamide drugs and amikacin, offering viable treatment options. [ABSTRACT FROM AUTHOR]

Nocardia farcinica is an aerobic gram-positive bacterium that is pathogenic to humans. It usually causes local and adjacent tissues’ diseases at the entry of infection (most commonly occur in the lungs, skin, or central nervous system), which can also spread to other organs through the bloodstream such as joints, kidneys, and liver. However, these infections are often seen as opportunistic that occur in immunocompromised patients. Here, we report for the first time two immunocompetent patients lacking evidence of local infections, with multiple lymph node enlargements and fever as main clinical manifestations, finally diagnosed as nocardiosis by Metagenomic Next-Generation Sequencing testing (mNGS) from formalin-fixed and paraffin-embedded (FFPE) lymph node tissue, after all the other standard tests were negative. Both patients recovered after receiving anti-nocardia therapies. These two cases indicates that in healthy population, there may be more potential nocardia infections than we expected. Multiple lymph node enlargements and fever suggest a possibility of nocardiosis, especially in patients with fever of unknown origin (FUO). mNGS detection from FFPE lymph node tissue is an accurate, reliable and traceable method for diagnosis of nocardiosis.

This article discusses a case study of a 64-year-old female kidney transplant recipient who developed a lung mass. The patient had received immunosuppressive medications and prophylactic antibiotics following the transplant. After presenting with weight loss, fever, and cough, the patient was diagnosed with Nocardia nova infection. Treatment with antibiotics led to significant improvement in the patient's condition. The article emphasizes the importance of considering Nocardia infection in immunocompromised patients and highlights the role of CT imaging in diagnosing and managing the condition. [Extracted from the article]

Abstract Background Nocardiosis is a rare infection that typically results from inhalation of or inoculation with Nocardia organisms. It may cause invasive disease in immunocompromised patients. This case describes nocardiosis with bacteremia and pulmonary involvement in a child with a hematologic malignancy. Case presentation A boy with testicular relapsed acute lymphoblastic leukemia with marrow involvement presented with sudden onset of fever, body aches, headaches, chills, and moderate respiratory distress during continuation 2 chemotherapy. Radiographic imaging demonstrated consolidation and ground glass opacities in bilateral lower lungs. Central line blood cultures grew Nocardia nova complex, prompting removal of the central line and initiation of triple therapy with imipenem-cilastatin, linezolid, and trimethoprim-sulfamethoxazole with rapid improvement of symptoms. Antibiotic susceptibilities showed a multidrug-susceptible isolate. The patient is anticipated to remain on trimethoprim-sulfamethoxazole for at least 12 months. Conclusions In an immunocompromised child, blood cultures, chest imaging, and head imaging can aid in the diagnosis of disseminated nocardiosis. Long-term antibiotic therapy is necessary, guided by the organism and simplified with the results of antimicrobial susceptibility testing.

Introduction Nocardia seriolae adversely impacts a diverse range of fish species, exhibiting significant pathogenic characteristics that substantially impede the progress of aquaculture. N. seriolae infects in fish has a long incubation period, and clinical symptoms are not obvious in the early stages. There is presently no viable and eco-friendly approach to combat the spread of the disease. According to reports, N. seriolae primarily targets macrophages in tissues after infecting fish and can proliferate massively, leading to the death of fish. Interferon-gamma (IFN-γ) is a crucial molecule that regulates macrophage activation, but little is known about its role in the N. seriolae prevention. Methods IFN-γ was first defined as largemouth bass (Micropterus salmoides, MsIFN-γ), which has a highly conserved IFN-γ characteristic sequence through homology analysis. The recombinant proteins (rMsIFN-γ) were obtained in Escherichia coli (E. coli) strain BL21 (DE3). The inflammatory response-inducing ability of rMsIFN-γ was assessed in vitro using monocytes/macrophages. Meanwhile, the protective effect of MsIFN-γ in vivo was evaluated by N. seriolae infection largemouth bass model. Results In the inflammatory response of the monocytes/macrophages activated by rMsIFN-γ, various cytokines were significantly increased. Interestingly, interleukin 1β (IL-1β) and tumor necrosis factor alpha (TNF-a) increased by 183- and 12-fold, respectively, after rMsIFN-γ stimulation. rMsIFN-γ improved survival by 42.1% compared with the control. The bacterial load in the liver, spleen and head kidney significantly decreased. rMsIFN-γ was also shown to better induce increased expression of IL-1β, TNF-α, hepcidin-1(Hep-1), major histocompatibility complex I (MHCI), and MHC II in head kidney, spleen and liver. The histopathological examination demonstrated the transformation of granuloma status from an early necrotic foci to fibrosis in the infection period. Unexpectedly, the development of granulomas was successfully slowed in the rMsIFN-γ group. Discussion This work paves the way for further research into IFN-γ of largemouth bass and identifies a potential therapeutic target for the prevention of N. seriolae. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to investigate the clinical features of Nocardia infections, antibiotic resistance profile, choice of antibiotics and treatment outcome, among others. In addition, the study compared the clinical and microbiological characteristics of nocardiosis in bronchiectasis patients and non-bronchiectasis patients. Methods: Detailed clinical data were collected from the medical records of 71 non-duplicate nocardiosis patients from 2017 to 2023 at a tertiary hospital in Zhengzhou, China. Nocardia isolates were identified to the species level using MALDI-TOF MS and 16S rRNA PCR sequencing. Clinical data were collected from medical records, and drug susceptibility was determined using the broth microdilution method. Results: Of the 71 cases of nocardiosis, 70 (98.6%) were diagnosed as pulmonary infections with common underlying diseases including bronchiectasis, tuberculosis, diabetes mellitus and chronic obstructive pulmonary disease (COPD). Thirteen different strains were found in 71 isolates, the most common of which were N. farcinica (26.8%) and N. cyriacigeorgica (18.3%). All Nocardia strains were 100% susceptible to both TMP-SMX and linezolid, and different Nocardia species showed different patterns of drug susceptibility in vitro. Pulmonary nocardiosis is prone to comorbidities such as bronchiectasis, diabetes mellitus, COPD, etc., and Nocardia is also frequently accompanied by co-infection of the body with pathogens such as Mycobacterium and Aspergillus spp. Sixty-one patients underwent a detailed treatment regimen, of whom 32 (52.5%) received single or multi-drug therapy based on TMP-SMX. Bronchiectasis was associated with a higher frequency of Nocardia infections, and there were significant differences between the bronchiectasis and non-bronchiectasis groups in terms of age distribution, clinical characteristics, identification of Nocardia species, and antibiotic susceptibility (P < 0.05). Conclusions: Our study contributes to the understanding of the species diversity of Nocardia isolates in Henan, China, and the clinical characteristics of patients with pulmonary nocardiosis infections. Clinical and microbiologic differences between patients with and without bronchiectasis. These findings will contribute to the early diagnosis and treatment of patients. [ABSTRACT FROM AUTHOR]

Nocardiosis is a rare infection due to a ubiquitous, gram-positive, weakly acid-fast, filamentous, aerobic bacteria, that are usually responsible for opportunistic infection in immunocompromised patients. Less frequently, nocardiosis can affect immunocompetent patients, causing primary cutaneous infections. Here we present a case of a 45-year-old housewife with a 12-day history of red painful nodules arranged linearly on her right upper limb, without any apparent history of injuries or comorbidities, albeit with a hobby of gardening. The unusual yet characteristic presentation, microbiological findings, and excellent response to co-trimoxazole therapy were consistent with a diagnosis of sporotrichoid primary cutaneous nocardiosis. The uncommon lymphocutaneous presentation is often misdiagnosed. Therefore, keeping a high index of suspicion in such cases is important to improve the cure rate and prevent complications. [ABSTRACT FROM AUTHOR]

Golden pompano (Trachinotus blochii) is a carnivorous teleost cultured in the Asia‐Pacific region. Fish culture in high densities and numbers results in disease outbreaks, causing huge economic losses. Here, we collected cultured golden pompanos from 2021 to 2022 and identified the pathogens isolated from the diseased fish. Out of a total of 64 clinical cases observed in both sea cages and fish ponds, it was found that Nocardia seriolae was the predominant pathogen (26%), followed by Lactococcus garvieae (13%). Trichodina spp. was the most prevalent parasite in sea cages and earthen ponds (21%), while Neobenedenia spp. was the primary parasitic pathogen (16%) in sea cages. Given these findings, further investigations were conducted, including antibiotic susceptibility and pathogenicity tests specific to N. seriolae in golden pompanos. Antibiotic susceptibility tests of N. seriolae revealed that all strains were susceptible to doxycycline, oxytetracycline, florfenicol and erythromycin but resistant to amoxicillin and ampicillin. Additionally, a pathogenicity assessment was carried out by administering an intraperitoneal injection of 0.1 mL containing 107 CFU of N. seriolae per fish. The mortality rates observed varied between 40% and 90%, with the P2 strain exhibiting the highest level of virulence, resulting in a cumulative mortality of 90%. Therefore, disease outbreaks in fish can be minimized by developing effective treatments and prevention methods. [ABSTRACT FROM AUTHOR]

Nocardiosis manifests as an opportunistic infection, primarily affecting individuals who are immunocompromised and susceptible to the infection. We present a case study of one patient with nephrotic syndrome and membranous nephropathy, who underwent treatment with prednisone and cyclosporine in 2016. In early 2017, the patient was diagnosed with a "fungal infection" and discontinued the use of cyclosporine. After one month of anti-infection therapy, a cranial magnetic resonance imaging scan showed multiple abscesses in the right temporal region. The diagnosis of nocardiosis was confirmed based on the presence of metastatic abscess masses, multiple lung and brain lesions, and a positive culture of Nocardia in the drainage. We changed the antiinfection therapy to a combination of trimethoprim-sulfamethoxazole (TMP-SMX), minocycline, and voriconazole. However, the patient experienced a sudden cardiac arrest and subsequently recovered after cardiopulmonary resuscitation. During the five-month follow-up period following the discharge, the patient displayed an enhanced nutritional status and stable renal function. The focal infection ultimately resolved during the subsequent three years. Neuro-infection caused by Nocardia should be considered in immunocompromised patients, and TMP-SMX is the preferred initial therapy; however, because of the high mortality rate, a long-term combination therapy with imipenem, cefotaxime, amikacin, and TMP-SMX is suggested. [ABSTRACT FROM AUTHOR]

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Nocardiosis is an acute purulent or granulomatous disease caused by Nocardia spp. infection that commonly invades the lungs and central nervous system. Hard-to-heal wounds caused by Nocardia spp. infection are rare. A 63-year-old female patient underwent puncture biopsy due to a mass in the right lung. Subsequently, dermal ulceration occurred on her back at the biopsy site, with no improvement following treatment at multiple hospitals. After admission to our department, bacterial culture of sputum and discharge from the deep wound sinus revealed Nocardia asteroides infection. The treatment regimen was developed by a multidisciplinary team at our department. The patient underwent debridement and vacuum sealing drainage (VSD) and was administered imipenem. The wound was then sealed by local flap transfer. The patient was discharged from the hospital after the wound had healed and continued to take minocycline for 2 months. At 3 months post-discharge, the symptoms of lung infection had resolved. Nocardiosis mainly affects the lungs, and its clinical symptoms are similar to those of pulmonary tuberculosis. Nocardia infections can extend to the chest wall and form abscesses or cellulitis. For hard-to-heal wounds caused by Nocardia spp., local debridement combined with systemic anti-infective therapy should be applied. In this case study, the diagnosis of pulmonary and wound nocardiosis was confirmed based on clinical manifestations, imaging, aetiological investigation and pathology. The treatment regimen was debridement combined with VSD, as well as a full course of antibiotics. The optimal treatment regimen for hard-to-heal wounds caused by Nocardia spp. includes effective debridement combined with VSD and long-course antibiotic therapy, which can improve the cure rate. Declaration of interest: The authors have no conflicts of interest. [ABSTRACT FROM AUTHOR]

In order to explore the antagonistic mechanism of Lysinibacillus sphaericus AEB18 against Nocardia seriolae, the whole genome of strain AEB18 was sequenced, and the effect of strain AEB18 in controlling nocardiosis of hybrid snakehead was verified in vitro and in vivo. Strain AEB18 genome was a circular DNA of 4,653,716 base pairs (bp) and GC content of 37.4%, predicting 4,529 coding genes, 108 tRNAs, 37 rRNAs, and 95 non-coding (nc)RNAs. The eggNOG (Non-supervised Orthologous Groups), GO (Gene Ontology), KEGG (Kyoto Encyclopedia of Genes and Genomes) and the CAZy (Carbohydrate-Associated Enzyme) database annotated the strain AEB18 genome to 3,965, 3,325, 2,061, and 112 genes, respectively. Furthermore, nine gene clusters, including polyketones, non-ribosomal synthetic peptides, β-lactones, terpenes, ribosomal synthetic peptides, and other secondary metabolites with bacteriostatic effect were obtained through the prediction of secondary metabolites of strain AEB18. After the addition of L. sphaericus AEB18 (1 × 109 CFU/g) with a mass fraction of 1% to the basal diet for 21 days, the weight gain rate and the activity of amylase in intestinal chyme of hybrid snakehead were significantly increased (P< 0.05). In addition, hybrid snakehead fed with L. sphaericus AEB18 supplemented diets showed significantly reduced mortality rate (P< 0.05) after N. seriolae infection, compared with the control group (mortality rate was 100%). Overall, L. sphaericus AEB18 positively affected hybrid snakeheads, promoted growth and reduced mortality rate of hybrid snakeheads with nocardiosis. Taken together, the L. sphaericus AEB18 possesses great potential as a biocontrol agent, which can be commercially developed to improve disease control in freshwater aquaculture. [ABSTRACT FROM AUTHOR]

Nocardia primarily affects immunocompromised individuals, and Infection with Nocardia is uncommon and primary cutaneous nocardiosis caused by percutaneous inoculation is even rarer. Primary cutaneous nocardiosis remains a diagnostic challenge and should be considered in the differential diagnosis for any superficial cutaneous infection that arises in patients with normal immune function. We report a case that was diagnosed with primary cutaneous Nocardia by metagenomic next‐generation sequencing technology. [ABSTRACT FROM AUTHOR]

Background: Nocardiosis is a rare infection that typically results from inhalation of or inoculation with Nocardia organisms. It may cause invasive disease in immunocompromised patients. This case describes nocardiosis with bacteremia and pulmonary involvement in a child with a hematologic malignancy. Case presentation: A boy with testicular relapsed acute lymphoblastic leukemia with marrow involvement presented with sudden onset of fever, body aches, headaches, chills, and moderate respiratory distress during continuation 2 chemotherapy. Radiographic imaging demonstrated consolidation and ground glass opacities in bilateral lower lungs. Central line blood cultures grew Nocardia nova complex, prompting removal of the central line and initiation of triple therapy with imipenem-cilastatin, linezolid, and trimethoprim-sulfamethoxazole with rapid improvement of symptoms. Antibiotic susceptibilities showed a multidrug-susceptible isolate. The patient is anticipated to remain on trimethoprim-sulfamethoxazole for at least 12 months. Conclusions: In an immunocompromised child, blood cultures, chest imaging, and head imaging can aid in the diagnosis of disseminated nocardiosis. Long-term antibiotic therapy is necessary, guided by the organism and simplified with the results of antimicrobial susceptibility testing. [ABSTRACT FROM AUTHOR]

We studied 50 patients with invasive nocardiosis treated during 2004-2023 in intensive care centers in France and Belgium. Most (65%) died in the intensive care unit or in the year after admission. Nocardia infections should be included in the differential diagnoses for patients in the intensive care setting. [ABSTRACT FROM AUTHOR]

Whether trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis prevents nocardiosis in solid organ transplant (SOT) recipients is controversial. To assess the effect of TMP-SMX in the prevention of nocardiosis after SOT, its dose-response relationship, its effect on preventing disseminated nocardiosis, and the risk of TMP-SMX resistance in case of breakthrough infection. A systematic review and individual patient data meta-analysis. MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Web of Science Core Collection, and Scopus up to 19 September 2023. (a) Risk of nocardiosis between SOT recipients with and without TMP-SMX prophylaxis, or (b) sufficient details to determine the rate of TMP-SMX resistance in breakthrough nocardiosis. SOT recipients. TMP-SMX prophylaxis versus no prophylaxis. Risk Of Bias In Non-randomized Studies-of Exposure (ROBINS-E) for comparative studies; dedicated tool for non-comparative studies. For our primary outcome (i.e. to determine the effect of TMP-SMX on the risk of nocardiosis), a one-step mixed-effects regression model was used to estimate the association between the outcome and the exposure. Univariate and multivariable unconditional regression models were used to adjust for the potential confounding effects. Certainty of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Individual data from three case-control studies were obtained (260 SOT recipients with nocardiosis and 519 uninfected controls). TMP-SMX prophylaxis was independently associated with a significantly decreased risk of nocardiosis (adjusted OR = 0.3, 95% CI 0.18–0.52, moderate certainty of evidence). Variables independently associated with an increased risk of nocardiosis were older age, current use of corticosteroids, high calcineurin inhibitor concentration, recent acute rejection, lower lymphocyte count, and heart transplant. Breakthrough infections (66/260, 25%) were generally susceptible to TMP-SMX (pooled proportion 98%, 95% CI 92–100). In SOT recipients, TMP-SMX prophylaxis likely reduces the risk of nocardiosis. Resistance appears uncommon in case of breakthrough infection. [Display omitted] [ABSTRACT FROM AUTHOR]

We report a rare case of pulmonary nocardiosis with endobronchial involvement caused by Nocardia araoensis. A 79-year-old man with a history of asthma and a previous right upper lobectomy for lung cancer and organizing pneumonia presented with cough and dyspnea. He presented with right bronchial stenosis associated with various mucosal lesions, including ulcerative and exophytic lesions. N araoensis was detected in sputum samples collected via bronchoscopy. The mucosal lesions improved after a 2-week course of meropenem. After a further 6 months of oral sulfamethoxazole-trimethoprim treatment, the mucosal lesions completely disappeared. Based on bronchoscopic and pathophysiologic findings, the patient was diagnosed with pulmonary nocardiosis with endobronchial involvement. Nocardiosis should be considered in the differential diagnosis of endobronchial mucosal lesions. [ABSTRACT FROM AUTHOR]

Nocardia are Gram‐positive bacteria from the Actinobacteria phylum. Some Nocardia species can infect humans and are usually considered to be opportunist pathogens, as they often infect immunocompromised patients. Although their clinical incidence is low, many Nocardia species are now considered to be emerging pathogens. Primary sites of infection by Nocardia are the skin or the lungs, but dissemination to other body parts is very frequent. These disseminated infections are very difficult to treat and thus are tackled with multiple classes of antibiotics, in addition to the traditional treatment targeting the folate pathway. β‐Lactams are often included in the regimen, but many Nocardia species present moderate or strong resistance to some members of this drug class. Genomic, microbiological and biochemical studies have reported the presence of class A β‐lactamases (ABLs) in a handful of Nocardia species, but no structural investigation of Nocardia β‐lactamases has yet been performed. In this study, the expression, purification and preliminary biochemical characterization of an ABL from an N. cyriacigeorgica (NCY‐1) clinical strain are reported. The crystallization and the very high resolution crystal structure of NCY‐1 are also described. The sequence and structural analysis of the protein demonstrate that NCY‐1 belongs to the class A1 β‐lactamases and show its very high conservation with ABLs from other human‐pathogenic Nocardia. In addition, the presence of one molecule of citrate tightly bound in the catalytic site of the enzyme is described. This structure may provide a solid basis for future drug development to specifically target Nocardia spp. β‐lactamases. [ABSTRACT FROM AUTHOR]

Nocardiosis is a rare infection of the lung, brain and skin and can be a localized or disseminated infection. Here, we report a case of a 56-year-old male patient who presented with a right testicular torsion for which right orchiectomy was done in the hospital. In the post-operative period, patient developed increased respiratory insufficiency and was intubated. Chest X-ray revealed bilateral fluffy opacities most likely due to infective etiology. Endotracheal tube aspirate sample was sent for Gram staining and culture, organism present showed characteristics like Nocardia. MALDI-TOF identified organism as Nocardia otitidiscaviarum. The patient was treated with cotrimoxazole and ceftriaxone. His clinical condition improved. We report this case because Nocardia otitidiscaviarum is a rare cause of pulmonary nocardiosis and although there is high mortality reported in nocardiosis, early diagnosis because of the availability of advanced diagnostic technology and prompt treatment can help save the patient. [ABSTRACT FROM AUTHOR]

Clinical guidelines list active fungal infection and sepsis as contraindications to liver transplantation due to the risk of worsening infection with immunosuppression postoperatively. Mortality from systemic opportunistic infections in transplant recipients is high, approaching 100% for disseminated aspergillosis. However, the optimal duration of treatment required before transplant is unclear. Additionally, delaying surgery while the infection is treated risks death from hepatic decompensation and physical deconditioning, preventing progression to transplantation. Here, we present a patient who underwent successful repeat liver transplantation for recurrent autoimmune hepatitis and graft rejection while undergoing treatment for disseminated aspergillosis and nocardiosis. He had pulmonary, hepatic, and central nervous system involvement. He had received 2 months of antimicrobials but had ongoing radiologic evidence of infection when listed for retransplantation. He remains well and infection-free 1 year postoperatively. Few cases of successful liver transplantation in the setting of disseminated aspergillosis have been reported previously. To our knowledge, this is the first successful liver transplant in a patient with disseminated nocardial infection. [ABSTRACT FROM AUTHOR]

A patient with disseminated nocardiosis developed pancytopenia after treatment with recombinant interferon-gamma (IFN-γ). While no previous clinical reports link pancytopenia to IFN-γ, our observations align with basic research on myelosuppressive effects of IFN-γ. Adjunctive IFN-γ may improve standard nocardiosis therapy, but vigilant monitoring of its hematologic effects is necessary.

Background As nocardiosis presents with nonspecific symptoms, its diagnosis is often difficult, resulting in high mortality. Here, we report a rare case of disseminated Nocardia farcinica infection that was successfully managed with a combination of antibiotic therapies. Case report A 71-year-old man with idiopathic thrombocytopenia purpura presented with sudden-onset motor aphasia, motor weakness of the right limb, and fever. Brain magnetic resonance imaging revealed multiple scattered diffusion-restricted lesions. Multiple cutaneous and peritoneal nodules were also identified. We performed full-length 16S ribosomal ribonucleic acid (rRNA) sequencing and obtained basic local alignment search tool results against the National Center for Biotechnology Information 16S rRNA database, which showed the best match to be N. farcinica. After maintaining the antibiotics for approximately 56 days, the patient recovered full consciousness, and the motor weakness of the right limb improved. Conclusion Timely diagnosis of disseminated or cerebral nocardiosis and treatment with appropriate antibiotics are crucial for a desirable clinical outcome.

We reviewed invasive Nocardia infections in 3 noncontiguous geographic areas in the United States during 2011–2018. Among 268 patients with invasive nocardiosis, 48.2% were from Minnesota, 32.4% from Arizona, and 19.4% from Florida. Predominant species were N. nova complex in Minnesota (33.4%), N. cyriacigeorgica in Arizona (41.4%), and N. brasiliensis in Florida (17.3%). Transplant recipients accounted for 82/268 (30.6%) patients overall: 14 (10.9%) in Minnesota, 35 (40.2%) in Arizona, and 33 (63.5%) in Florida. Manifestations included isolated pulmonary nocardiosis among 73.2% of transplant and 84.4% of non–transplant patients and central nervous system involvement among 12.2% of transplant and 3.2% of non–transplant patients. N. farcinica (20.7%) and N. cyriacigeorgica (19.5%) were the most common isolates among transplant recipients and N. cyriacigeorgica (38.0%), N. nova complex (23.7%), and N. farcinica (16.1%) among non–transplant patients. Overall antimicrobial susceptibilities were similar across the 3 study sites.

Objective: Nocardia is clinically rare but highly pathogenic in clinical practice. Due to the lack of Nocardia screening methods, Nocardia is often missed in diagnosis, leading to worsening the condition. Therefore, this paper proposes a Nocardia screening method based on neural networks, aiming at quick Nocardia detection in sputum specimens with low costs and thereby reducing the missed diagnosis rate. Methods: Firstly, sputum specimens were collected from patients who were infected with Nocardia, and a part of the specimens were mixed with new sputum specimens from patients without Nocardia infection to enhance the data diversity. Secondly, the specimens were converted into smears with Gram staining. Images were captured under a microscope and subsequently annotated by experts, creating two datasets. Thirdly, each dataset was divided into three subsets: the training set, the validation set and the test set. The training and validation sets were used for training networks, while the test set was used for evaluating the effeteness of the trained networks. Finally, a neural network model was trained on this dataset, with an image of Gram-stained sputum smear as input, this model determines the presence and locations of Nocardia instances within the image. Results: After training, the detection network was evaluated on two datasets, resulting in classification accuracies of 97.3% and 98.3%, respectively. This network can identify Nocardia instances in about 24 milliseconds per image on a personal computer. The detection metrics of mAP50 on both datasets were 0.780 and 0.841, respectively. Conclusion: The Nocardia screening method can accurately and efficiently determine whether Nocardia exists in the images of Gram-stained sputum smears. Additionally, it can precisely locate the Nocardia instances, assisting doctors in confirming the presence of Nocardia. [ABSTRACT FROM AUTHOR]

Background: Nocardiosis is a rare, but potentially life-threatening condition. It is difficult to diagnose, and bacterial culture identification can be time consuming. We investigated the characteristics of nocardiosis and the suitability of the treatment approach in Korea. Materials and Methods: This retrospective study was conducted at 5 medical institutions between 2011 and 2021. We reviewed the medical records of patients with microbiologically confirmed nocardiosis. Appropriate antibiotic selection was defined as follows: (1) selecting antibiotics according to the species, (2) if the species of Nocardia was unknown, trimethoprim-sulfamethoxazole-based therapy or linezolid-based therapy was administered, and (3) selection of antibiotics using the antibiotic susceptibility test. The appropriate treatment periods for antibiotics were defined as treatment maintained from 3 to 12 months, depending on involvement of the organs. Descriptive analysis and Fisher exact test were used. Statistical significance was set at P-values of <0.05. Results: Thirty patients were enrolled. Of these patients, 18 (60.0%) were male. The median age was 70.5 years. Among the diagnosed patients, 12 (40.0%) had an immunocompromised status. Eight (30.0%) patients received optimal treatment for the appropriate treatment period. Appropriate dosing duration was observed in 3 of the 12 (25.0%) immunocompromised patients. There was no significant difference between the presence or absence of immunosuppression and the adequacy of treatment for nocardiosis (P = 1.000). Skin and soft tissue (14 patients) were most frequently involved in this study. Nocardia species (spp.) were isolated from culture at a median of 6.0 days. There were 7 cases with N. farcinica (23.3%). Conclusion: We found that 60.0% of the patients with nocardiosis did not have an immunocompromised status. Further, 26.7% of the total patients received adequate treatment for nocardiosis. The reasons for suboptimal management of nocardiosis in Korea are presumed to be diagnostic difficulties, lack of awareness about nocardiosis, and difficulties in selecting antibiotics for Nocardia spp. among clinicians. The lack of antibiotic susceptibility tests for Nocardia spp. could be the source of these problems. Nocardiosis should be suspected in cases of recurrent infections with skin and soft tissue, musculoskeletal, or respiratory system involvement with or without an immunocompromised status. Clinical microbiological support is required for the diagnosis and selection of antibiotics in Korea. High clinical index of suspicion and clinical microbiological support are required for the accurate diagnosis of nocardiosis in Korea. [ABSTRACT FROM AUTHOR]