Search Results (123)

Produced water (PW) is the largest waste stream generated during oil and gas production and poses significant environmental challenges, particularly in water-scarce regions. This study presents a multi-tiered assessment of PW from six Libyan oilfields across three sedimentary basins, integrating physicochemical characterization, trace metal and lithium analysis, radiological evaluation, and molecular identification of selected cultured bacterial isolates. Results revealed substantial variability, with total dissolved solids ranging from 8443 to 222,000 mg/L, chloride up to 153,423 mg/L, and total petroleum hydrocarbons reaching 98.5 mg/L. Elevated concentrations of barium, strontium, iron, and mercury exceeded guideline limits in selected samples. Radiological analysis indicated low radionuclide activity in the aqueous phase, while scanning electron microscopy confirmed NORM accumulation in sulfate-rich mineral scales. Molecular identification using 16S rRNA sequencing revealed hydrocarbon-degrading bacteria, including Microbacterium ureisolvens, Exiguobacterium aquaticum, Kocuria rosea, and Nocardia coubleae, with the latter two, to the best of our knowledge, reported for the first time in PW environments. These findings provide insight into selected cultured bacterial isolates associated with PW and their potential relevance for bioremediation. Overall, the results provide a baseline understanding of PW characteristics in the analyzed samples and emphasize the need for further large-scale investigations. Full article

Background: Adenoids play a pivotal role in immune system maturation during early childhood; however, pathological adenoid hypertrophy is associated with significant morbidity. Although infectious and immunological factors have been implicated, the role of the nasopharyngeal microbiome in adenoid hypertrophy remains incompletely understood. Methods: In this cross-sectional study, the nasopharyngeal microbiome of 26 children diagnosed with symptomatic hypertrophic adenoids was compared with that of 30 age-matched healthy controls with non-hypertrophic adenoids. Microbial profiling was performed using 16S rRNA (ribosomal ribonucleic acid)gene sequencing. Alpha and beta diversity, core microbiome, network and differential abundance analyses were performed. Results: Alpha diversity showed significant group differences (Fisher’s alpha p = 0.048), while beta diversity was not significant. Both groups had a common core microbiome dominated by Moraxella, Haemophilus, Staphylococcus, Streptococcus, Corynebacterium and Dolosigranulum, while Fusobacterium was identified exclusively in the study group. Dolosigranulum, Corynebacterium, Finegoldia and Micrococcus were characteristic in the control group, while Campylobacter, Paludibacteraceae, Fusobacterium, Escherichia-Shigella, Cutibacterium and Nocardia were typical in the study group. Conclusions: When compared with healthy controls, children with symptomatic hypertrophic adenoids exhibit a distinct nasopharyngeal microbiome characterized by altered microbial community structure and shifts in specific bacterial taxa. These findings support a potential role of the microbiome in the pathogenesis of adenoid hypertrophy. Full article

To perform the first concurrent characterization of gut and respiratory microbiome profiles in colorectal cancer patients from Western Siberia, Russia. We analyzed synchronous fecal and sputum samples from 40 treatment-naive colorectal cancer patients and 45 healthy controls using 16S rRNA gene (V3-V4) sequencing and QIIME 2-based bioinformatic workflows. While alpha-diversity indices did not differ significantly between groups, beta-diversity analysis revealed substantial compositional differences for both ecosystems. Colorectal cancer patients exhibited gut enrichment of Proteobacteria, Fusobacteria, Fusobacterium, Odoribacter, Lachnospiraceae_UCG-010, Erysipelatoclostridium, Parvimonas, Finegoldia, Clostridium and Bacteroides (Bacteroides fragilis), alongside sputum enrichment of phyla Bacteroidetes and Actinobacteria, as well as genera Neisseria, Prevotella, Lactobacillus, Rothia, Nocardia, Leptotrichia, Campylobacter, and Helicobacter. Stage-associated shifts included elevated Akkermansia in gut microbiomes of patients with advanced-stage disease and higher Campylobacter in early-stage sputum. These findings identify distinct gut–respiratory dysbiotic signatures in a previously understudied population. Our results underscore the potential of dual-compartment microbiome profiling for developing non-invasive biomarkers and require validation in larger, multicenter cohorts to elucidate mechanistic links between respiratory dysbiosis and colorectal carcinogenesis. Full article

Nocardia spp. and Mycobacterium spp. are known etiological agents of granulomatous pulmonary infections in humans and animals; however, co-infections involving these pathogens have not previously been reported in veterinary medicine. This paper describes the first documented case of co-infection with Mycobacterium bovis and Nocardia spp. in a captive roan antelope (Hippotragus equinus). The animal was a 9-year-old female roan antelope from a safari park in northern Italy that died suddenly with a one-month history of weight loss. Post-mortem examination revealed severe, diffuse, chronic granulomatous pneumonia associated with fibrino-granulomatous pleuritis and granulomatous pericarditis. Histologically, multifocal to coalescing necrotizing granulomas were observed, with intralesional acid-fast bacteria. Microbiological culture and biomolecular analyses allowed the identification of M. bovis and Nocardia spp. in lung tissue samples. The Nocardia genome sequence was 98.5% similar to N. tengchongensis, a recently discovered species. The findings emphasize the importance of comprehensive diagnostic approaches in animal granulomatous lung disease. Mixed infections in captive wildlife represent a One Health concern, as the potential for zoonotic adaptation and transmission to humans cannot be excluded. Therefore, pathogen surveillance is of particular importance within zoological collections. Full article

Background Granulomatous lung diseases include a spectrum of disorders, both infectious and noninfectious, unified by the presence of granulomas in the lung parenchyma. Granulomas are microscopic, organized collections of immune cells that arise as a response to persistent antigenic stimulation. Infectious granulomatous lung diseases arise from a variety of microbial agents, that include most frequently Mycobacterium tuberculosis, non-tuberculous mycobacteria, Nocardia, and Borrelia, as well as a wide range of fungal pathogens including Histoplasma, Cryptococcus, Pneumocystis, and Aspergillus species. Methods and Results: Definitive diagnosis is achieved through direct identification and subsequent culture of the causative pathogen in appropriate clinical specimens, including sputum, bronchoscopic samples, gastric aspirates, or pleural fluid. Imaging is fundamental for the detection and characterization of pulmonary granulomas. HRCT allows precise assessment of the number, size, and distribution of granulomatous lesions, can suggest an infectious etiology based on specific imaging patterns, and is essential for monitoring response to therapy over time. Differential diagnosis is challenging due to the numerous different imaging appearances with whom granulomatous lung diseases may manifest. Conclusions: The purpose of our review is to describe the spectrum of infectious granulomatous lung diseases caused by bacterial pathogens, highlighting their diverse radiologic presentations in order to assist radiologists in recognizing these entities and improving diagnostic accuracy. Full article

This study investigated the dose-dependent effects of dietary glycerol monolaurate (GML) supplementation on the growth performance, bile acid metabolism, and intestinal health of Asian swamp eel (Monopterus albus). A total of 225 healthy eels with an initial body weight of 25.0 ± 2.0 g were randomly divided into three groups and fed a basal diet (control), 0.5 g/kg GML, or 1.0 g/kg GML for 60 days, respectively. The results showed that dietary GML supplementation increased the weight gain rate by 8.75% and decreased the feed conversion ratio by 8.16% in the GML1 group compared with the control. Dietary GML significantly reduced the contents of TP and ALB (p < 0.05). Meanwhile, the MDA content in the GML0.5 and GML1 groups decreased significantly by 24.80% and 38.15%, respectively. The contents of total bile acids and secondary bile acids were significantly elevated in the GML1 group (p < 0.05). In addition, GML supplementation optimized the intestinal microbial community and significantly reduced the relative abundance of potentially harmful bacteria such as Nocardia and Stenotrophomonas (p < 0.05). In conclusion, under the conditions of this study, dietary GML could effectively the improve growth performance, bile acid metabolism, antioxidant capacity, and intestinal health of M. albus. Among the tested concentrations, 1.0 g/kg GML showed the optimal beneficial effects. Full article

Silver Pomfret is increasingly threatened by many diseases under intensive artificial culturing conditions, yet conserved host biomarkers across different infections remain poorly defined. In this study, we integrated transcriptomic datasets from independent infections with Cryptocaryon irritans, Nocardia seriolae, and Photobacterium damselae subsp. damselae to identify shared host-response genes. By combining differential expression analysis with weighted gene co-expression network analysis, we prioritized six candidate genes associated with cross-pathogen infection responses. Random Forest and support vector machine analysis further supported their classification potential across the three infection models. Phylogenetic and structural analyses provided additional evidence for the conserved annotation of these proteins. GSVA-based signature analysis supported the cross-pathogen discriminatory capacity of the six-gene panel and suggested context-dependent contributions of individual genes across infection models. Immune signature analysis indicated distinct host immune response patterns under different pathogenic challenges, and candidate genes showed positive associations with inferred T cell-related signatures. Upstream regulatory prediction identified CTCF and the miR-17/20/93 family as potential regulators of these genes. Quantitative real-time PCR of the kidney further highlighted canx, rnd3, and angptl4 as the most robust infection-responsive candidates, with consistent temporal expression patterns observed from 0 to 24 h post-infection. These findings suggest a potential cross-pathogen host-response pattern in Silver Pomfret and provide preliminary support for future exploration of molecular markers for disease monitoring in aquaculture. Full article

In October 2025, an outbreak occurred among farmed Chinese rice-field eels (Monopterus albus) in Jiangxi, China. A Nocardia seriolae strain designated JXMa251025, which has not been previously documented in Chinese rice-field eels, was isolated from moribund fish exhibiting multiple white nodules of various sizes in visceral tissues. Histopathological examination revealed multi-organ damage, including necrosis of liver cells, granulomatous inflammation with hemorrhage in visceral organs, and necrosis of renal glomeruli and tubules accompanied by vascular congestion. Artificial infection trials confirmed that strain JXMa251025 reproduced clinical signs consistent with those observed in the natural outbreak. Infection experiments resulted in 100% mortality in high-concentration challenge groups, with a median lethal dose (LD₅₀) of 9.76 × 10⁵ CFU/mL, indicating high virulence. Whole-genome sequencing revealed a circular chromosome of 8,295,032 bp with a GC content of 68.10%. The genome contains 66 tRNA genes and four copies each of the 23S, 16S, and 5S rRNA genes. Phylogenomic analysis placed strain JXMa251025 within a clade of Nocardia seriolae strains with approximately 99% bootstrap support, confirming its identification as Nocardia seriolae. Further genomic screening identified 253 potential virulence genes associated with nutrient metabolism, regulatory systems, immune modulation, effector delivery, and exotoxin production. Antibiotic susceptibility testing showed that strain JXMa251025 was sensitive to seven antibiotics: ciprofloxacin, neomycin, enrofloxacin, florfenicol, gentamicin, amikacin, and doxycycline. This study represents the first report of Nocardia seriolae infecting Chinesse rice-field eels, providing useful descriptive information for disease diagnosis and reference. Full article

In this study, a Nocardia niigatensis strain was isolated from boron-rich mining soils in the Bigadiç region of Türkiye and comprehensively characterized. The primary aim of this study was to isolate boron-tolerant Nocardia species and evaluate their physiological, enzymatic, and biochemical profiles. Selective isolation techniques were employed to obtain Nocardia isolates, and species-level identification was achieved using both 16S rRNA gene sequencing and MALDI-TOF MS analysis, which consistently confirmed the isolate as N. niigatensis. In addition to molecular identification, the morphological, physiological, and biochemical characteristics of the strain were extensively investigated. The strain demonstrated notable boron tolerance, exhibiting robust growth at concentrations up to 50 mM, highlighting its potential applicability in the bioremediation of boron-contaminated environments. Physiological assays further revealed moderate halotolerance and a mesophilic growth profile, with optimal growth observed at 27–37 °C. Enzymatic screening indicated positive L-glutaminase activity, an enzyme of considerable industrial relevance. Moreover, API ZYM profiling revealed a broad enzymatic spectrum, including esterases, arylamidases, phosphatases, and glucosidases, suggesting substantial metabolic versatility. Antibiotic susceptibility testing showed sensitivity to doxycycline, tobramycin, and erythromycin, whereas resistance was observed against imipenem and several β-lactam antibiotics. Metagenomic analysis of boron-rich soils from two distinct mining sites revealed marked differences in microbial community composition, with variations in Actinobacteria abundance associated with mineral type. Overall, these findings emphasize the adaptive capacity and biotechnological potential of environmental Nocardia strains inhabiting chemically stressful ecosystems, warranting further genomic and metabolomic investigations. Full article

This study aimed to evaluate the effects of trimethylamine oxide (TMAO) supplementation (0.5% and 1%) to a high-carbohydrate diet on the growth performance, liver health, hepatic metabolome, intestinal microbiota and disease resistance of largemouth bass (Micropterus salmoides). After an eight-week feeding trial with three replicates, fish fed with TMAO-supplemented diets showed growth-promoting potential with increased difference with a prolonged rearing period. Importantly, TMAO supplementation significantly improved liver structure and function, with reduced intrahepatic glycogen accumulation due to reprogrammed glycogen metabolism, including down-regulated gys2 and ugp2b but up-regulated pygl expression levels. Targeted liver metabolomics analysis indicated the enhanced synthesis of long-chain fatty acid and amino acid in the 1% TMAO group, accompanied by decreased cortisol, indicating the attenuation of the stress response. Furthermore, TMAO supplementation changed the structure of the intestinal microbiota and particularly the intestinal content of Romboutsia, an important probiotic that can effectively utilize different kinds of dietary carbohydrate, showed an increasing trend with the increased TMAO supplementation levels. Finally, after sampling, all remaining fish were challenged with Nocardia seriolae. TMAO supplementation significantly enhanced the immune clearance function of largemouth bass against invading N. seriolae, with alleviated granulomatous nodules within liver but enhanced hepatic expression levels of nlrp3, caspase1, il-1β and il-18. These results collectively underscore the finding that TMAO may promote intestinal Romboutsia growth and reprogram hepatic metabolism to improve liver health, giving TMAO potential as a feed additive for growth and health promotion in largemouth bass. Full article

Nocardia seriolae (N. seriolae) is a significant bacterial pathogen in global aquaculture, causing substantial economic losses. Live-attenuated vaccines represent a promising control strategy, but their molecular mechanisms remain poorly understood. This study employed a quantitative proteomic approach to compare the proteomic profiles of a virulent wild-type strain (F1) and an attenuated vaccine strain (F110) of N. seriolae. Using a data-independent acquisition (DIA)-based LC-MS/MS analysis, we identified 4516 proteins, with 540 showing significant differential expression (311 upregulated, 229 downregulated). Bioinformatic analysis revealed that upregulated proteins in F110 were primarily involved in metabolic processes, including phosphatidate cytidylyltransferase and various enzymes related to amino acid and nucleotide metabolism. Conversely, downregulated proteins were enriched in virulence-associated functions, including HtpX and MFS transporter permease. These findings suggest that attenuation involves a complex reprogramming of metabolic pathways coupled with a reduction in key virulence factors, providing insights into the potential molecular basis of vaccine development and potential targets for novel therapeutic strategies. Full article

Cervicofacial actinomycosis is a well-recognized infectious disease caused by Actinomyces, a Gram-positive filamentous bacterium. In contrast, Nocardia, a morphologically similar, hyphae-forming organism, is an exceedingly rare cause of cervicofacial abscesses, and even more uncommon associated osteomyelitis of mandible. We present such a case involving a kidney transplant recipient who presented with opioid-induced constipation, along with left jaw pain and swelling. CT scan of the soft tissue in the neck revealed a complex cervicofacial abscess with enhancement of underlying mandible. Culture growth and RNA sequencing of USG-guided aspirate identified a Nocardia species closely related to N. beijingensis/exalbida. The patient initially received broad-spectrum antibiotics, including ceftriaxone, imipenem, and trimethoprim-sulfamethoxazole (TMP-SMX). Imipenem was later discontinued in view of new-onset unexplained encephalopathy and replaced with linezolid, which was subsequently switched to minocycline following thrombocytopenia development. Minocycline therapy was intended for a total of 12 months. TMP-SMX was avoided long-term due to avoid nephrotoxicity risk in kidney transplant patients. On six-month follow-up, the patient showed clinical and radiological improvement; minocycline was discontinued after additional six months. This case highlights the importance of considering Nocardia as a differential diagnosis in immunosuppressed patients presenting with cervicofacial symptoms, especially following orofacial surgery or trauma. Early recognition, prompt diagnosis, and appropriate antibiotic therapy with adequate bone penetration seem crucial for optimal management and may help avoid the need for surgical intervention. Full article

The extensive use of agrochemicals, heavy metals, and antibiotics in agriculture poses significant challenges to environmental sustainability and soil health. Plant growth-promoting bacteria (PGPB) offer a promising solution for sustainable agriculture; however, their selection requires careful evaluation of factors such as genome stability, metal tolerance, antibiotic resistance, and pesticide degradation capacity. This study characterizes the endolithic Nocardia mangyaensis NH1, focusing on its physiological and genomic features that enhance its potential as a biofertilizer in contaminated soils. Genomic analysis revealed a low number of antibiotic resistance genes with susceptibility to broad-spectrum antibiotics, minimizing the risk of horizontal gene transfer. The genome of N. mangyaensis NH1 contains two non-pathogenic genomic islands and prophage regions, with a CRISPR–Cas9 system. These findings highlight N. mangyaensis NH1 as a promising candidate for biofertilizers, combining pesticide and metal tolerance with genomic stability, thereby supporting sustainable agricultural practices and reducing environmental risks associated with agrochemical use. Full article

Nocardia seriolae infection poses a serious threat to largemouth bass (Micropterus salmoides) aquaculture, owing to the lack of effective control strategies. This study investigated the antibacterial effects and underlying mechanisms of Macleaya cordata alkaloids—sanguinarine (SE) and chelerythrine (CHE)—against N. seriolae through integrated physiological and transcriptomic approaches. Results showed SE and CHE exhibited strong in vitro antibacterial activity, with minimum inhibitory concentrations (MICs) of 62.5 and 7.8 μg/mL, respectively. In vivo trials revealed that dietary supplementation with either alkaloid significantly enhanced the survival of infected fish, yielding relative percent survival (RPS) values of 34.5% for SE and 40.0% for CHE. Concurrently, both treatments reduced bacterial load and alleviated granulomatous pathology in multiple organs, including the liver, spleen, and kidney. Physiological analyses revealed severe damage to the cell envelope, as evidenced by increased membrane permeability and structural disintegration observed under transmission electron microscopy (TEM). Transcriptomic profiling identified 3708 and 5095 differentially expressed genes (DEGs) in the SE- and CHE-treated groups, respectively, with notable downregulation of key genes involved in peptidoglycan biosynthesis, the citrate cycle, oxidative phosphorylation, and the pentose phosphate pathways. These findings demonstrate that SE and CHE inhibit N. seriolae through a multi-target mechanism simultaneously disrupting cell envelope integrity and energy production, laying the groundwork for their development as eco-friendly aquaculture therapeutics. Full article