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.

Occipital Nocardia Abscess Presenting With Positive Visual Phenomenon and Quadrantanopsia.

ABSTRACT: A 74-year-old man with chronic obstructive pulmonary disease, glaucoma, and Stage IIIB squamous cell lung cancer experienced several minutes of flashing lights in his right visual hemifield, followed by onset of a right visual field defect. On examination, the patient had a right homonymous hemianopsia that was most dense inferiorly by confrontation testing. Emergent CT scan of the head revealed a 2.5 × 3 cm hypodensity in the left occipital lobe, which was interpreted as an acute stroke. Continuous EEG monitoring captured left posterior quadrant seizures that were temporally correlated to the positive visual phenomena. Subsequent MRI of the brain with and without contrast revealed a conglomerate of centrally necrotic and peripherally enhancing mass lesions. On biopsy, a thick purulent material was drained and Gram stain of the sample revealed gram-positive beaded rods, which speciated to Nocardia farcinica . The patient was treated with a six-week course of intravenous meropenem and a one-year course of oral trimethroprim-sulfamethoxazole. On follow-up, the patient experienced resolution of the right visual field deficit.

Nocardia spp. isolation in chronic lung diseases: Are there differences between patients with pulmonary nocardiosis and Nocardia colonization?

AIMS: Chronic lung diseases are a recognized risk factor for Nocardia spp. INFECTION: Nocardia spp. isolation does not inevitably imply disease, and thus colonization must be considered. Here, we aimed to analyse the differences between pulmonary nocardiosis (PN) and Nocardia spp. colonization in patients with chronic lung diseases. METHODS AND RESULTS: A retrospective study of patients with laboratory confirmation of isolation of Nocardia spp. in at least one respiratory sample was performed. Patients with PN and Nocardia spp. colonization were compared. There were 71 patients with Nocardia spp. identification, 64.8% were male, with a mean age of 67.7 ± 11.2 years. All patients had ≥1 pre-existing chronic lung disease, and 19.7% of patients were immunocompromised. PN and Nocardia spp. colonization were considered in 26.8% and 73.2% of patients, respectively. Symptoms and chest CT findings were significantly more frequent in patients with PN (p < 0.001). During follow-up time, 12 (16.9%) patients died, 6 in PN group. Immunosuppression, constitutional symptoms, haematological malignancy and PN diagnosis were associated with significantly shorter survival times, despite only immunosuppression (HR 3.399; 95% CI 1.052-10.989) and PN diagnosis (HR 3.568; 95% CI 1.078-11.910) remained associated with a higher death risk in multivariate analysis. CONCLUSIONS: PN was associated with clinical worsening, more chest CT findings and worse clinical outcomes. SIGNIFICANCE AND IMPACT OF STUDY: Nocardia spp. isolation in chronic lung disease patients is more common than expected and the differentiation between colonization and disease is crucial.

Molecular characterization and biological function of CXCR1 in Nocardia seriolae-infected largemouth bass (Micropterus salmoides).

Interleukin-8 (IL-8, CXCL8), a pro-inflammatory chemokine secreted by a variety of cell types, plays a critical role in the development of various immune diseases. Interactions between IL-8 and its receptor CXC receptor 1/2 (CXCR1/2) are known to promote chemotaxis and phagocytosis in many immune responses. In this study, we report the molecular characteristics and pharmacological activity of CXCR1 (MsCXCR1) in largemouth bass (Micropterus salmoides) and evaluated the functional involvement of MsCXCR1 in individuals infected with the pathogen Nocardia seriolae. MsCXCR1 was cloned into the pEGFP-N1 plasmid and the subcellular localization of MsCXCR1 on the cell membrane was verified in MsCXCR1-EGFP-expressing HEK293 cells. Following observation of receptor internalization and intracellular signaling detection, we further determined the functional interaction of secreted interleukin-8 (LcIL-8, the ligand for CXCR1 in large yellow croaker) and MsCXCR1 was further determined, and the ERK phosphorylation signal activation mediated by MsCXCR1 was demonstrated. Quantitative real-time PCR assays were conducted to analyze the transcriptional distribution of MsCXCR1 in various tissues of healthy and diseased largemouth bass. These results illustrate the significant elevation of MsCXCR1 expression in the head kidney, spleen and liver of M. salmoides, suggesting that MsCXCR1 was involved in the immune response in N. seriolae-infected largemouth bass and potentially affects the digestive function of this species.

Nocardia beijingensis lung mass in an immunocompetent adult.

A 47-year-old man was referred for ongoing workup of an enlarging lung mass. Extensive workup of the mass had been unrevealing for several months until cultures grew Nocardia beijingensis He was successfully treated with trimethoprim/sulfamethoxazole and then doxycycline with near-complete resolution of the mass on follow-up. This case presents a rare species of N. beijingensis It highlights the importance of considering nocardiosis in immunocompetent adults and the challenge in initiating targeted treatment due to delayed culture results.

Clinical features and prognosis of nocardiosis in patients with connective tissue diseases.

OBJECTIVES: To investigate the clinical features and prognosis of nocardiosis complicated by connective tissue diseases (CTDs). METHODS: We examined patients with CTDs who were diagnosed with nocardiosis from October 2004 to 2019. We retrospectively investigated patient characteristics and therapeutic outcomes. We then performed a comparison between survivors and non-survivors. RESULTS: Fourteen patients were examined. Underlying CTDs were systemic lupus erythematosus (28.6%), vasculitis syndrome (28.6%), rheumatoid arthritis (21.4%), adult Still disease (14.3%) and dermatomyositis (7.1%). Infected organs were lung (85.7%), brain (42.9%), skin/cutaneous lesions (28.6%) and muscle (7.1%). Disseminated infections were seen in nine patients (64.3%). At the onset of nocardiosis, all patients were given prednisolone (23.2 ± 11.9 mg/day). Only two patients (14.3%) were given TMP-SMX for prophylaxis of pneumocystis pneumonia. Relapse occurred in one patient (7.1%) and four patients (28.6%) died from nocardiosis for a cumulative survival rate at 52 weeks of 76.9%. In a comparison of survivors (71.4%) and non-survivors (28.6%), cutaneous lesions were significantly more frequent in the latter (10 vs 75%, p = .04) with an odds ratio of 27.0 (95% CI: 1.7-453.4). CONCLUSION: Cutaneous lesions as a result of dissemination might be a risk factor for nocardiosis mortality in patients with CTDs.

Clinical correlates of nocardiosis.

Nocardia is an opportunistic pathogen that most frequently affects the lungs. Evidence is limited regarding the risk factors for nocardiosis. The current study assessed clinical correlates of nocardiosis. A retrospective study was conducted based on medical records of consecutive adult patients (N = 60) with nocardiosis hospitalized during 2007-2018 at a tertiary hospital in central Israel. A matched comparison group of 120 patients was randomly selected among hospitalized patients with community-acquired pneumonia. Multivariable conditional logistic regression models were fitted. Immunosuppressive pharmacotherapy was positively associated with nocardiosis (matched odds ratio [OR] 4.40, 95% confidence interval [CI] 2.25-8.62, p < 0.001), particularly corticosteroid therapy (matched OR 4.69, 95% CI 2.45-8.99, p < 0.001). Systemic corticosteroid therapy was strongly associated with pulmonary nocardiosis (matched OR 5.90, 95% CI 2.75-12.66, p < 0.001). The positive association between solid organ transplantation and nocardiosis was attenuated following adjustment for systemic corticosteroids in a multivariable model. The association between corticosteroid therapy and nocardiosis appeared stronger in patients with chronic pulmonary disease (OR 5.74, 95% CI 2.75-12.66, p < 0.001) than in the pooled analysis of all nocardiosis cases. In conclusion, corticosteroid therapy was strongly correlated with nocardiosis, particularly among individuals with chronic pulmonary disease and in pulmonary nocardiosis.

A rare disease mimicking lung cancer.

We present an interesting case of a 34 year old gentleman with bilateral FDG avid lesions in the apex of the lung. He presented with a two month history of cough, fever and hemoptysis. A contrast enhanced CT scan showed a spiculated lesion in the right upper lobe. A CT guided biopsy was done which was suggestive of an inflammatory lesion. He was started empirically on anti tubercular therapy, but his symptoms did not subside. A PET CT scan was done, which showed the lesion to be FDG avid. A repeat biopsy was done and again it was reported as an inflammatory infiltrate. He was then referred to our center for a surgical biopsy. We repeated a PET scan and were surprised to find another lesion in the apex of the opposite lung. The case was discussed with our interventional pulmonogy team and an EBUS guided biopsy of the lesion was done. On microbiological analysis the specimen was found to be positive for Nocardia.

Cutaneous nocardiosis: A great imitator.

Nocardiosis is caused by Gram-positive aerobic bacilli of the Nocardia genus, which are saprophytes living in the soil. It is a rare and opportunist disease with a localized or disseminated infection. When occurring in patients who are immunocompromised, involvement is usually systemic, most commonly represented by pulmonary disease. It can also be acquired through direct inoculation, entailing primary skin and subcutaneous tissue infections, frequently presenting as a localized nodular process. Cutaneous nocardiosis can manifest as a lymphocutaneous infection, actinomycetoma, superficial skin infection, or secondary infection from hematogenic dissemination. Diagnosis is made by identification of the organism in the culture of a clinical sample. Staining for acid-alcohol-resistant bacteria and, especially, Gram staining, is particularly relevant to obtain a rapid and presumptive diagnosis, while awaiting culture results. First-line medication is sulfamethoxazole-trimethoprim, which may be used with other antimicrobials, if necessary. Nocardiosis may be considered a major mimicker of several cutaneous diseases that present difficult, and often, delayed diagnoses.

Pulmonary Nocardiosis in Suspected Tuberculosis Patients: A Systematic Review and Meta-Analysis of Cross-Sectional Studies.

BACKGROUND: nocardiosis is an opportunistic infectious disease in immunocompromised patients. The most common form of nocardiosis infection in humans is pulmonary nocrdiosis caused by inhaling Nocardia species from the environment. Thus, this study aimed to evaluate the pulmonary nocardiosis in patients with suspected tuberculosis using systematic review and meta-analysis. METHODS: We conducted a systematic search for cross-sectional studies focused on the pulmonary nocardiosis among patients with pulmonary tuberculosis based on the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) published from January 2001 to October 2019. The search was conducted in MEDLINE/PubMed, Web of Science, Scopus, Cochrane Library, Google Scholar, Science Direct databases, and Iranian databases. Medical subject headings (MeSH) and text words were searched: "pulmonary nocardiosis", "nocardiosis", OR "nocardial infection", "pulmonary nocardial infections/agents", AND "pulmonary tuberculosis", OR "pulmonary TB", AND "Iran". Two of the reviewers enrolled independently articles published in English and Persian languages according to the inclusion and the exclusion criteria. Comprehensive Meta-Analysis software (Version 3.3.070) was used for meta-analysis. RESULTS: Only 4 studies met the eligibility criteria. The pulmonary nocardiosis prevalence varied from 1.7% to 6.7%. The combined prevalence of nocardiosis among patients with suspected pulmonary tuberculosis in Iran was 4.8% (95% CI: 3-7.3, Q=5.8, Z=12.7). No heterogeneity was observed between studies because I2 was 48.3. N. cyriacigeorgica and N. asteroides were reported as the prevalent isolates, respectively. CONCLUSIONS: This review showed in patients suspected TB when they were negative in all diagnosis laboratory tests, nocardiosis cases which be considered.

A case report of disseminated nocardiosis with ocular involvement in a myasthenia gravis patient and literature review.

BACKGROUND: Nocardiosis is a rare and life-threatening opportunistic infection in immunocompromised patients. Myasthenia gravis (MG) patients are potentially at risk of nocardia infection because of the use of immunosuppressive agents. To date, only 7 patients with MG have been reported to have nocardiosis. Disseminated nocardiosis with ocular involvement has not been reported in MG patients. CASE PRESENTATION: A 66-year-old man with MG who was receiving treatment with methylprednisolone and azathioprine was found to have a respiratory infection. He also had heterogeneous symptoms with skin, brain and ocular manifestations. Nocardia bacteria verified by the culture of puncture fluid, and a diagnosis of disseminated nocardiosis was made. Except for left eye blindness, the patient completely recovered from the disease with combination antibiotic therapy. To further understand nocardiosis in patients with MG, we reviewed the previous relevant literature. According to the literature, this is the first report of disseminated nocardiosis with ocular involvement in an MG patient. CONCLUSIONS: MG patients with immunosuppressant treatments are potentially at risk of a rare nocardia infection, and a favourable prognosis can be achieved through early diagnosis and appropriate antibiotic therapy.