Nocardia implantans sp. nov. isolated from a patient with pulmonary infection.

TwoGram-stain-positive and rod-shaped actinomycetes (strains CDC186T and CDC192) were isolated from sputum samples of a patient in Chongqing, PR China, and were investigated to determine their taxonomic status. The results of phylogenetic analysis based on the 16S rRNA gene indicated that CDC186T and CDC192 represented members of the genus Nocardia, and the sequence similarity with Nocardia beijingensis DSM 44636T was the highest, at 99.71 and 99.78 %, respectively. The DNA G+C content of both CDC186T and CDC192 was 69.1 %. Genomic diversity analysis revealed that the average nucleotide identity and in silico DNA‒DNA hybridisation values between the two novel strains and closely related species were significantly below the thresholds of 95-96 and 70 %, respectively, but these values between the two novel strains were 99.96 and 99.90 %, respectively. The phylogenetic relationship based on the dapb1 gene and the single-copy core genes further indicated that the two novel strains were clustered in separate branch adjacent to N. beijingensis DSM 44636T. Growth occurred within the ranges of 20-42 °C, pH 6.0-9.0 and NaCl concentrations of 0.5-4.5 % (w/v). The major fatty acids of CDC186T and CDC192 were C16 : 0 and C18 : 0 10-methyl [tuberculostearic acid (TBSA)]. The predominant respiratory menaquinone was MK-9. The polar lipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannoside, one unidentified glycolipid, one unidentified phospholipid and one unidentified phosphoglycolipid. All the genomes of the studied strains were annotated with virulence factor (VF)-associated genes homologous to those of Mycobacterium tuberculosis, and the results of susceptibility testing indicated that CDC186T and CDC192 were resistant to amoxicillin-clavulanic acid and tigecycline. On the basis of chemotaxonomic characteristics and the results of phylogenetic analyses, strains CDC186T and CDC192 represent a novel species within the genus Nocardia, for which the name Nocardia implantans sp. nov. is proposed. The type strain is CDC186T (=GDMCC 4.206T= JCM 34959T).

[Cholestasis, delirium and pulmonary nocardiosis in a man with systemic lupus erythematosus of late onset]. / Colestasis, delirium y nocardiosis pulmonar en un varón con lupus eritematoso sistémico de inicio tardío.

A case is presented of a 64-year-old male patient who was admitted because of delirium, jaundice, a pattern of cholestasis in the liver profile and a right lung mass in the context of a constitutional syndrome and weight loss in the last eight months. The lung mass was punctured and the culture of the obtained material developed white colonies, identified by mass spectrometry (MALDI-TOF) as Nocardia cyriacigeorgica. Regarding the clinical diagnosis, it was considered as systemic lupus erythematosus (SLE), on the basis of fulfilling 8 criteria according to SLICC 2012 group, and 24 points according to EULAR/ACR 2019. The liver biopsy showed a mixt cellular infiltrate in portal spaces, with absence of interphase hepatitis and presence of peripheral ductular reaction. These findings were interpreted as liver compromise relate to SLE. Delirium was also considered as a neurological manifestation related to SLE on the basis of ruling out other causes. After being treated with antibiotics and documenting a reduction in the size of the lung mass he received cyclophosphamide in intravenous pulses, achieving normalization of his liver profile and his state of consciousness, and a progressively weight recovering. A year after he was in good health. The report of this case is justified because of the rare presenting form of late onset SLE, as well as the concomitant pulmonary nocardiosis in the absence of previous immunosuppressant treatment.

Se presenta el caso de un varón de 64 años que fue internado por delirium asociado a ictericia con patrón de colestasis en el hepatograma, y una masa en el pulmón derecho en el contexto de pérdida de peso y síndrome constitucional de 8 meses de evolución. Se realizó punción de la masa pulmonar cuyo cultivo desarrolló colonias blanquecinas identificadas como Nocardia cyriacigeorgica por espectrometría de masas (MALDI-TOF MS). Se llegó al diagnóstico de lupus eritematosos sistémico (LES) por presentar 8 de los criterios de acuerdo con el grupo SLICC 2012 y 24 puntos de acuerdo a los criterios EULAR/ACR 2019. La biopsia hepática mostró leve y variable infiltrado inflamatorio mixto en espacios porta, con ausencia de hepatitis de interfase y presencia de reacción ductular periférica. Se interpretaron estos hallazgos como vinculados a hepatopatía por LES. El delirium fue interpretado como afectación neurológica por LES en base al descarte de otras enfermedades. Recibió tratamiento antibiótico y tras constatarse reducción del tamaño de la masa pulmonar se administraron pulsos de ciclofosfamida intravenosa. Evolucionó favorablemente, con normalización del hepatograma y el estado de conciencia, y recuperación del peso en forma progresiva. Al año se lo encontró en buen estado de salud. Justifica el reporte del caso la rara forma de presentación del LES de comienzo tardío, así como la nocardiosis pulmonar concomitante sin tratamiento inmunosupresor previo.

Fever of unknown origin revealing testicular nocardiosis: a case report and literature review.

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.

Disseminated nocardiosis presenting as a superinfected thyroglossal duct cyst in a patient with diabetes.

We introduce the case of a male patient in his 60s who was admitted to our emergency department with a persisting sore throat for the last 3 weeks and dysphagia. Fibre-endoscopic evaluation revealed an asymmetry at the base of the tongue. In combination with elevated white cell count and C reactive protein, a computerized tomography showed a superinfected thyroglossal duct cyst. Intravenous antibiotics were initiated, and the patient was taken to the operating room for cervicotomy. The microbiological swab taken intraoperatively detected Nocardia paucivorans Additional imaging revealed disseminated nocardiosis with cerebral and pulmonary manifestations.The patient was treated with oral trimethoprim/sulfamethoxazole and, over time, showed complete remission of central nervous system lesions and improvement of pulmonary involvement. Following this, the treatment was stopped 8 months after the initial diagnosis. In this report, we discuss treatment standards and outcomes of nocardiosis based on our management strategies of our patient.

Weathering the storm: diagnosis and treatment of a life-threatening disseminated Nocardia otitidiscaviarum infection.

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.

Fatal Nocardia paucivorans Lower Respiratory Tract Infection in a Tuberculosis Suspect Who Worked as Gold Miner.

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.

Nocardia brasiliensis Pyomyositis in an Immunocompetent Patient Following Gardening Activity.

Nocardia pyomyositis in immunocompetent patients is a rare occurrence. The diagnosis may be missed or delayed with the risk of progressive infection and suboptimal or inappropriate treatment. We present the case of a 48-year-old immunocompetent firefighter diagnosed with pyomyositis caused by Nocardia brasiliensis acquired by direct skin inoculation from gardening activity. The patient developed a painful swelling on his right forearm that rapidly progressed proximally and deeper into the underlying muscle layer. Ultrasound imaging of his right forearm showed a 7-mm subcutaneous fluid collection with surrounding edema. Microbiologic analysis of the draining pus was confirmed to be N brasiliensis by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry. After incision and drainage deep to the muscle layer to evacuate the abscess and a few ineffective antibiotic options, the patient was treated with intravenous ceftriaxone and oral linezolid for 6 weeks. He was then de-escalated to oral moxifloxacin for an additional 4 months to complete a total antibiotic treatment duration of 6 months. The wound healed satisfactorily and was completely closed by the fourth month of antibiotic therapy. Six months after discontinuation of antibiotics, the patient continued to do well with complete resolution of the infection. In this article, we discussed the risk factors for Nocardia in immunocompetent settings, the occupational risks for Nocardia in our index patient, and the challenges encountered with diagnosis and treatment. Nocardia should be included in the differential diagnosis of cutaneous infections, particularly if there is no improvement of "cellulitis" with traditional antimicrobial regimens and the infection extends into the deeper muscle tissues.

Chronic inflammatory demyelinating polyneuropathy with pulmonary nocardiosis: A case report.

RATIONALE: Chronic inflammatory demyelinating polyneuropathy (CIDP) is an immune-mediated motor sensory peripheral neuropathy that is rare in clinical practice. This treatment method aims to suppress potential immunopathology. Nocardiosis is a rare, destructive, opportunistic disease. We report a case of failed treatment of CIDP combined with pulmonary nocardiosis, and for the first time, we link these 2 diseases together. PATIENT CONCERNS: A 65-year-old man developed symmetrical limb weakness. Four months later, he was diagnosed with CIDP and started receiving glucocorticoid (GC) treatment. The disease progressed slowly and was treated with mycophenolate mofetil (MMF) in combination. He did not follow the doctor requirements for monthly follow-up visits, and the preventive medication for sulfamethoxazole/trimethoprim was not strictly implemented. Two months after the combination therapy, the patient developed fever, coughing and sputum production, as well as fatigue and poor appetite. Based on imaging and etiological results, he was diagnosed with pulmonary nocardiosis. DIAGNOSES: Chronic inflammatory demyelinating polyneuropathy, pulmonary nocardiosis. INTERVENTIONS: After treatment with antibiotics, the patient lung infection temporarily improved. However, the patient CIDP condition progressed, limb weakness worsened, respiratory muscle involvement occurred, and intravenous immunoglobulin (IVIG) was administered. However, there was no significant improvement in the condition, and the patient died. OUTCOMES: In this report, we present a case of a patient with CIDP and pulmonary nocardiosis. It is worth noting that in order to avoid the progression and recurrence of CIDP, we did not stop using related therapeutic drugs during the treatment process, the patient had repeatedly refused to use IVIG. Despite this, the patient condition worsened when lung inflammation improved, leading to persistent respiratory failure and ultimately death. Treatment contradictions, medication issues, and patient compliance issues reflected in this case are worth considering. LESSONS: For patients with CIDP receiving immunosuppressive therapy, attention should be paid to the occurrence and severity of Nocardia infection. Therefore, early detection and treatment are necessary. We need to pay attention to the compliance of patients with prophylactic use of antibiotics, strengthen the follow-up, and urge them to return to their appointments on time.

Nocardia keratitis after small incision lenticule extraction (SMILE).

We report the case of a female patient in her late 20s who visited the clinic with concerns about poor vision, redness, watering and a burning sensation in her left eye 2 weeks after undergoing a small incision lenticule extraction. She had no history of systemic illness or immunosuppressed status. On slit lamp examination, she was found to have corneal stromal infiltrates in the interface at multiple locations. Given the clinical diagnosis of microbial keratitis, corneal scraping of the interface infiltrate was performed and sent for microbiological examination revealing gram-positive, thin, beaded filaments that were acid-fast positive and later identified by growth in culture media as Nocardia species. This case was managed successfully with the use of topical amikacin and systemic trimethoprim-sulfamethoxazole with complete resolution of infection.

A rare case of primary cutaneous Nocardia vinacea in an immunocompetent patient: A case report and a review of the literature.

The nocardiae are a complex group of bacteria belonging to the aerobic saprophytes actinomycetes. Although nocardiosis typically occurs in immunocompromised patients, infection may occasionally develop in immunocompetent patients as well. Here we describe a rare case of primary cutaneous nocardiosis due to Nocardia vinacea in an immunocompetent 79-year-old patient. Since cutaneous nocardiosis presents variably and mimics other cutaneous infections, acid-fast and Gram stainings on clinical samples are significant to obtain a rapid and presumptive diagnosis.

Characterization of the equine placental microbial population during nocardioform placentitis.

Nocardioform placentitis is a poorly understood disease of equine late gestation. The presence of nocardioform, filamentous branching gram-positive bacteria, has been linked to the disease, with Crossiella equi, Amycolatopsis spp., and Streptomyces spp. being the most frequently identified bacteria. However, these bacteria are not found in all clinical cases in addition to being isolated from healthy, normal postpartum placentas. To better understand this form of placentitis, we analyzed the microbial composition in the equine placenta (chorioallantois) of both healthy postpartum (control; n = 11) and nocardioform-affected samples (n = 22) using 16S rDNA sequencing. We found a lower Shannon index in nocardioform samples, a higher Chao1 index in nocardioform samples, and a difference in beta diversity between control and nocardioform samples (p < 0.05), suggesting the presence of dysbiosis during the disease. In the majority of the NP samples (77 %), one of the following genera-Amycolatopsis, Crossiella, Lentzea, an unidentified member of the Pseudonocardiaceae family, Mycobacterium, or Enterococcus -represented over 70 % of the relative abundance. Overall, the data suggest that a broader spectrum of potential opportunistic pathogens could be involved in nocardioform placentitis, extending beyond the traditionally recognized bacteria, resulting in a similar histomorphological profile.

Enhanced effectiveness in preventing Nocardia seriolae infection utilizing heterologous prime-boost approach in orange-spotted grouper Epinephelus coioides.

Persistent nocardiosis has prompted exploration of the effectiveness of heterologous approaches to prevent severe infections. We have previously reported the efficacy of a nucleic acid vaccine in protecting groupers from highly virulent Nocardia seriolae infections. Ongoing research has involved the supplementation of recombinant cholesterol oxidase (rCho) proteins through immunization with a DNA vaccine to enhance the protective capacity of orange-spotted groupers. Recombinant rCho protein exhibited a maturity and biological structure comparable to that expressed in N. seriolae, as confirmed by Western blot immunodetection assays. The immune responses observed in vaccinated groupers were significantly higher than those observed in single-type homologous vaccinations, DNA or recombinant proteins alone (pcD:Cho and rCho/rCho), especially cell-mediated immune and mucosal immune responses. Moreover, the reduction in N. seriolae occurrence in internal organs, such as the head, kidney, and spleen, was consistent with the vaccine's efficacy, which increased from approximately 71.4 % to an undetermined higher percentage through heterologous vaccination strategies of 85.7 %. This study underscores the potential of Cho as a novel vaccine candidate and a heterologous approach for combating chronic infections such as nocardiosis.

Bacteremia caused by Nocardia farcinica: a case report and literature review.

BACKGROUND: Nocardia farcinica is one of the most common Nocardia species causing human infections. It is an opportunistic pathogen that often infects people with compromised immune systems. It could invade human body through respiratory tract or skin wounds, cause local infection, and affect other organs via hematogenous dissemination. However, N. farcinica-caused bacteremia is uncommon. In this study, we report a case of bacteremia caused by N. farcinica in China. CASE PRESENTATION: An 80-year-old woman was admitted to Peking Union Medical College Hospital with recurrent fever, right abdominal pain for one and a half month, and right adrenal gland occupation. N. farcinica was identified as the causative pathogen using blood culture and plasma metagenomics next-generation sequencing (mNGS). The clinical considerations included bacteremia and adrenal gland abscess caused by Nocardia infection. As the patient was allergic to sulfanilamide, imipenem/cilastatin and linezolid were empirically administered. Unfortunately, the patient eventually died less than a month after the initiation of anti-infection treatment. CONCLUSION: N. farcinica bacteremia is rare and its clinical manifestations are not specific. Its diagnosis depends on etiological examination, which can be confirmed using techniques such as Sanger sequencing and mNGS. In this report, we have reviewed cases of Nocardia bloodstream infection reported in the past decade, hoping to improve clinicians' understanding of Nocardia bloodstream infection and help in its early diagnosis and timely treatment.

Identification and functional analysis of perforin 1 from largemouth bass (Micropterus salmoides).

In this study, we present the first cloning and identification of perforin (MsPRF1) in largemouth bass (Micropterus salmoides). The full-length cDNA of MsPRF1 spans 1572 base pairs, encoding a 58.88 kDa protein consisting of 523 amino acids. Notably, the protein contains MACPF and C2 structural domains. To evaluate the expression levels of MsPRF1 in various healthy largemouth bass tissues, real-time quantitative PCR was employed, revealing the highest expression in the liver and gut. After the largemouth bass were infected by Nocardia seriolae, the mRNA levels of MsPRF1 generally increased within 48 h. Remarkably, the recombinant protein MsPRF1 exhibits inhibitory effects against both Gram-negative and Gram-positive bacteria. Additionally, the largemouth bass showed a higher survival rate in the N. seriolae challenge following the intraperitoneal injection of rMsPRF1, with observed reductions in the tissue bacterial loads. Moreover, rMsPRF1 demonstrated a significant impact on the phagocytic and bactericidal activities of largemouth bass MO/MΦ cells, concurrently upregulating the expression of pro-inflammatory factors. These results demonstrate that MsPRF1 has a potential role in the immune response of largemouth bass against N. seriolae infection.

Risk factors for Nocardia infection among allogeneic hematopoietic cell transplant recipients: A case-control study of the Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation.

OBJECTIVES: Nocardiosis is a rare but life-threatening infection after hematopoietic cell transplantation (HCT). We aimed at identifying risk factors for nocardiosis after allogeneic HCT and clarifying the effect of trimethoprim-sulfamethoxazole prophylaxis on its occurrence. METHODS: We performed a retrospective multicenter case-control study of patients diagnosed with nocardiosis after allogeneic HCT between January 2000 and December 2018. For each case, two controls were matched by center, transplant date, and age group. Multivariable analysis was conducted using conditional logistic regression to identify potential risk factors for nocardiosis. Kaplan-Meier survival curves of cases and controls were compared using log-rank tests. RESULTS: Sixty-four cases and 128 controls were included. Nocardiosis occurred at a median of 9 months after allogeneic HCT (interquartile range: 5-18). After adjustment for potential confounders in a multivariable model, Nocardia infection was associated with tacrolimus use (adjusted odds ratio [aOR] 9.9, 95 % confidence interval [95 % CI]: 1.6-62.7), lymphocyte count < 500/µL (aOR 8.9, 95 % CI: 2.3-34.7), male sex (aOR 8.1, 95 % CI: 2.1-31.5), recent use of systemic corticosteroids (aOR 7.9, 95 % CI: 2.2-28.2), and recent CMV infection (aOR 4.3, 95 % CI: 1.2-15.9). Conversely, use of trimethoprim-sulfamethoxazole prophylaxis was associated with a significantly decreased risk of nocardiosis (aOR 0.2, 95 % CI: 0.1-0.8). HCT recipients who developed nocardiosis had a significantly decreased survival, as compared with controls (12-month survival: 58 % and 90 %, respectively; p < 0.0001). CONCLUSIONS: We identified six factors independently associated with the occurrence of nocardiosis among allogeneic HCT recipients. In particular, trimethoprim-sulfamethoxazole prophylaxis was found to protect against nocardiosis.

Pathological variations and immune response in Channa argus infected with pathogenic Nocardia seriolae strain.

Nocardia seriolae pathogen causes chronic granulomatous disease, reportedly affecting over 40 species of marine and freshwater cultured fish. Hence, research is required to address and eliminate this significant threat to the aquaculture industry. In this respect, a reliable and reproducible infection model needs to be established to better understand the biology of this pathogen and its interactions with the host during infection, as well as to develop new vaccines or other effective treatment methods. In this study, we examined the pathogenicity of the pathogen and the immune response of snakehead (Channa argus) juvenile to N. seriolae using a range of methods and analyses, including pathogen isolation and identification, histopathology, Kaplan-Meier survival curve analysis, and determination of the median lethal dose (LD50) and cytokine expression. We have preliminarily established a N. seriolae - C. argus model. According to our morphological and phylogenetic analysis data, the isolated strain was identified as N. seriolae and named NSE01. Eighteen days post-infection of healthy juvenile C. argus with N. seriolae NSE01, the mortality rate in all four experimental groups (intraperitoneally injected with 1 × 105 CFU/mL - 1 × 108 CFU/mL of bacterial suspension) (n = 120) was 100 %. The LD50 of N. seriolae NSE01 for juvenile C. argus was determined to be 1.13 × 106 CFU/fish. Infected juvenile C. argus had significant pathological changes, including visceral tissue swelling, hemorrhage, and the presence of numerous nodules of varying sizes in multiple tissues. Further histopathological examination revealed typical systemic granuloma formation. Additionally, following infection with N. seriolae NSE01, the gene expression of important cytokines, such as Toll-like receptor genes TLR2, TLR13, interleukin-1 receptor genes IL1R1, IL1R2, and interferon regulatory factor IRF2 were significantly upregulated in different tissues, indicating their potential involvement in the host immune response and regulation against N. seriolae. In conclusion, juvenile C. argus can serve as a suitable model for N. seriolae infection. The establishment of this animal model will facilitate the study of the pathogenesis of nocardiosis and the development of vaccines.

Complement C1q is involved in the activation of membrane attack complexes, regulation of bacterial infectious inflammation, and apoptosis through overexpression in primary cells of silver pomfret (Pampus argenteus) in vitro.

The complement system is pivotal in innate immune defense, with Complement 1qb (C1qb) playing a key role in recognizing immune complexes and initiating the classical pathway. In this research, we cloned the full-length cDNA of silver pomfret (Pampus argenteus) c1qb and demonstrated its role in mediating defense responses against Nocardia seriolae (N. seriolae) infection, which notably causes significant economic losses in the aquaculture industry. Our investigation revealed that N. seriolae infection led to tissue damage in fish bodies, as observed in tissue sections. Subsequent analysis of differential genes (DEGs) in the transcriptome highlighted genes linked to apoptosis and inflammation. Through experiments involving overexpression and interference of c1qb in vitro, we confirmed that c1qb could suppress N. seriolae-induced apoptosis and inflammation. Moreover, overexpression of c1qb hindered N. seriolae invasion, and the purified and replicated C1qb protein displayed antimicrobial properties. Additionally, our study unveiled that overexpression of c1qb might stimulate the expression of membrane attack complexes (MAC), potentially enhancing opsonization and antibacterial effects. In conclusion, our findings offer valuable insights into the immune antibacterial mechanisms of c1qb and contribute to the development of strategies for controlling N. seriolae.

Clinical characteristics and drug resistance of Nocardia in Henan, China, 2017-2023.

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.

Pancytopenia following adjuvant therapy with interferon-gamma in a patient with disseminated nocardiosis.

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.