Search Results (1,570)

The family Pasteurellaceae includes pathogenic and opportunistic bacteria affecting poultry, yet taxonomic resolution remains challenging due to phenotypic heterogeneity, limited genomic representation, and the poor performance of routine diagnostic systems for uncommon taxa. At the Clemson Veterinary Diagnostic Center, a Gram-negative bacterium was isolated from a backyard hen. The isolate produced two distinct colony morphotypes with identical biochemical profiles. They were misidentified as Sphingomonas paucimobilis by VITEK^® 2, while MALDI-TOF MS failed to identify them. Oxford Nanopore long-read sequencing with PacBio HiFi polishing generated near-complete chromosome-level assemblies. Comparative genomic analyses demonstrated that morphotypes CVDC-smooth and CVDC-rough represent clonal variants of a distinct Spirabiliibacterium lineage sharing 93% average nucleotide identity (ANI) and 52% digital DNA–DNA hybridization (dDDH) with the closest relative, Spirabiliibacterium mucosae. Copy-number variation within a tandemly duplicated ~20 kb genomic region may contribute to differences in colony morphology. Family-wide analysis identified lineage-associated gene patterns and a limited number of VFDB-matched virulence genes in the CVDC isolates. This study identifies a distinct lineage within the genus Spirabiliibacterium, reports the first isolation and chromosome-level genome assemblies of a Spirabiliibacterium lineage from a chicken in the United States, and highlights the limitations of routine diagnostic methods for identifying uncommon bacterial taxa. Full article

Bovine bacterial mastitis remains a major challenge for the dairy industry, and timely identification of causative bacteria is essential for effective disease management. This study compared six regions of the 16S rRNA gene for PCR high-resolution melt (HRM) curve analysis to identify the most suitable target for species-level differentiation of mastitis-associated bacteria. A total of 547 clinical bovine milk samples from cows with clinical mastitis were cultured, and representative isolates of 18 bacterial species were selected for comparative analysis. Species identity was confirmed using matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) prior to molecular analysis. All six primer pair combinations were tested across the 18 species panel, and discriminatory performance was assessed using a genotype confidence percentage (GCP)-based classification model that allowed for objective interpretation without visual inspection. Among the six target regions, the 203 bp amplicon generated by primer pair F1R1, spanning the V1-to-V2 region and part of V3, showed the strongest overall discriminatory performance with no cross-classification observed. Sequencing of F1R1 amplicons confirmed species identity and showed concordance with HRM-based classification. Phylogenetic analysis of sequences from this region showed clustering broadly consistent with established taxonomic relationships. Proof-of-concept testing showed that the workflow could also be applied to DNA extracted directly from selected milk samples without prior bacterial isolation. Overall, this approach provides a rapid, cost-effective, and high-throughput method for preliminary discrimination of mastitis-associated bacteria. Full article

A 4-year-old spayed female domestic shorthair cat was referred with history of 8 months of chronic, non-healing draining wounds on the left lateral thigh and left inguinal region. The initial lesions arose from a cat bite wound on the thigh and a concurrent inguinal subcutaneous mass, both of which had failed to respond to empirical antimicrobial therapy. Prior to referral, cytology of the inguinal mass suggested a spindle cell tumor; however, histopathology following surgical excision revealed severe necrotizing pyogranulomatous mastitis and dermatitis, with no evidence of neoplasia. At the initial referral visit, bacterial cultures from both lesions yielded Mycobacterium farcinogenes, identified via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The cat was treated with pradofloxacin, topical amikacin gel, and azithromycin despite in vitro resistance, resulting in complete clinical remission after 24 weeks without adverse effects. To our knowledge, this is the first reported case of feline cutaneous mycobacteriosis caused by M. farcinogenes in Asia. This case expands the limited veterinary literature on M. farcinogenes infection, highlights the diagnostic challenges of atypical mycobacterial infections, emphasizes the critical role of species-level identification, and demonstrates the efficacy of prolonged, multidrug therapy in managing chronic non-healing wounds in cats. Full article

We report the synthesis of a modified benzothiazole sulfide. This compound contains a heterocyclic core, a Boc-protected hydroxylamine, and an appended alkyne. This benzothiazole was accessed through three total steps, including an amidation reaction and two nucleophilic aromatic substitutions. The identity of the title compound was confirmed through ¹H, ¹³C, ¹H–¹H COSY, HSQC, and HMBC NMR, in addition to IR, MALDI-MS, HRMS, and HPLC. Full article

We previously demonstrated the therapeutic potential of a 0.5% miltefosine carbopol-based gel (G-MTF) in experimental cutaneous leishmaniasis (CL). To support formulation optimisation before clinical evaluation, this study assessed whether G-MTF retained antileishmanial activity after storage at different temperatures and durations and evaluated its dose–response following topical application to CL lesions in BALB/c mice infected with Leishmania amazonensis. Storage effects on some physicochemical and morphological properties, sterility, and MTF detection were also assessed. In vitro antileishmanial activity was largely maintained, although prolonged storage at 35–45 °C moderately reduced potency. During 60 days of follow-up, CL lesions reactivated in 17% of the 118 treated mice, with most reactivations occurring after treatment with G-MTF formulations stored for 3–6 months at 35–45 °C. Dose–response analysis showed concentration-dependent effects on lesion reduction and parasite burden, with estimated ED₅₀ values of 3.64 and 4.02 mg/kg, respectively. All carbopol-based gel formulations remained sterile and retained physicochemical characteristics at 8–28 °C, with pH values within the normal skin range. Storage at 8 °C increased viscosity and reduced spreadability, whereas higher temperatures increased swelling. MALDI-TOF MS demonstrated that MTF remained detectable after prolonged storage, while SEM showed preserved morphology at 8–28 °C. Overall, carbopol-based G-MTF maintained therapeutic activity and acceptable physicochemical characteristics for up to six months at 8–28 °C. Validated quantitative stability-indicating and drug-release methods are needed to confirm MTF chemical stability and drug availability in the carbopol-based gel. Full article

Asthma is a heterogeneous disease that often begins in childhood and frequently occurs alongside allergic conditions. In asthma research, it is important to focus on proteins that are the primary regulators of cellular physiology. The differences in the proteome between children with asthma and those with an atopic background remain poorly understood. The present study included 130 serum samples from four groups of pediatric patients under the age of five: (1) with asthma and IgE-dependent allergies; (2) with non-atopic asthma; (3) non-asthmatics with IgE-dependent allergy; and (4) a control group without asthma and IgE-dependent allergies. The serum samples were used for protein–peptide profiling and proteomic identification using nanoLC-MALDI-TOF/TOF MS/MS. The obtained data were analyzed using univariate statistics and the STRING tool v12.0 to identify protein–protein potential interactions. A total of seven proteins were identified as discriminative between the study groups: A2M, AACT, IgG3, C3, ITIH2, IgG3 and IGK. All of them were upregulated in patients with IgE-dependent allergy compared to other study groups. STRING analysis identified functional associations among four proteins (AACT, A2M, C3, and ITIH2) with discriminatory potential for distinguishing between non-atopic asthma and non-asthmatic patients with IgE-dependent allergy. The results suggest that the identified putative protein markers overlap in cellular pathways, including those associated with the pathophysiology of asthma and allergic disorders. These findings provide further insight into the overall proteomic profile of pediatric patients with asthma and IgE-dependent allergy, highlighting its heterogeneity across the analyzed groups. Full article

Ready-to-cook Asian moon scallop (RAM) may harbor seafood-associated spoilage and opportunistic pathogenic bacteria, leading to quality deterioration and food safety concerns. This study investigated the microbiological diversity, virulence-associated phenotypes, and antibacterial activity of chitooligosaccharide–epigallocatechin gallate conjugate (CEGC) combined with nisin against seafood-associated bacteria isolated from RAM. A total of 102 bacterial isolates were subjected to identification by MALDI-TOF/MS, with Vibrio, Aeromonas, and Shewanella as the predominant genera. Several isolates exhibited proteolytic and hemolytic activities, indicating spoilage potential and virulence-associated traits. Multivariate analysis showed that bacterial isolates differed widely in their antimicrobial susceptibility and virulence-associated phenotypes. Checkerboard assays demonstrated synergistic effects between CEGC and nisin against Vibrio parahaemolyticus and Vibrio fluvialis (FICI = 0.50). The additive effects were observed for the remaining strains, except an indifferent effect (FICI = 1.06) was found for A. hydrophila. The combined treatment markedly inhibited bacterial growth and biofilm formation, achieving approximately 95% biofilm reduction in V. parahaemolyticus. Confocal laser scanning microscopy and scanning electron microscopy revealed severe membrane disruption, increased permeability, cellular deformation, and collapse of biofilm architecture. Furthermore, CEGC–nisin effectively suppressed V. parahaemolyticus growth in cold-stored RAM. These findings demonstrate that CEGC combined with nisin is a promising natural antimicrobial strategy for improving seafood safety and reducing microbial spoilage in ready-to-cook seafood products. Full article

To date, four species of the genus Edwardsiella—E. tarda, E. ictaluri, E. piscicida, and E. anguilarum—have been identified as the cause of disease and mortality in various fish species. Thirty-six Edwardsiella strains isolated from different fish species in the Netherlands were identified using multilocus sequence analysis (MLSA) based on sequence analysis of the genes gyrB, pgi and phoU. In parallel, an Edwardsiella matrix-assisted laser desorption ionization–time-of-flight mass spectrometry (MALDI-TOF MS) database was created by analyzing peptide spectra of a subset of these strains belonging to the four fish pathogenic species. MALDI-TOF MS analysis of the Edwardsiella isolates using the newly created database revealed 100% agreement with results of MLSA. Moreover, the presence of each Edwardsiella species was associated with specific fish host and source, with E. piscicida being the dominant species in Dutch aquaculture. In addition, a novel strain was isolated from electric eel, genetically diverging from the four established species. Whole-genome comparisons of the novel strain with those species showed DNA-DNA hybridization and average nucleotide identity scores suggestive of a new species. In conclusion, both MLSA and MALDI-TOF analysis can be used to identify Edwardsiella species. Moreover, it has been observed that different Edwardsiella species show a preference for certain hosts or sources. Full article

Background and Objectives: Antimicrobial resistance (AMR) is a major challenge, particularly in intensive care units, where broad-spectrum therapy is often initiated before microbiological confirmation. Artificial intelligence (AI) may improve AMR prediction, but its clinical value depends on integration with bioengineering-enabled digital microbiology. This narrative review examines how AI, bioengineering platforms and digital microbiology can support AMR prediction, clinical decision support and antimicrobial stewardship across the sample-to-decision pipeline. Materials and Methods: A targeted narrative review was conducted using PubMed/MEDLINE and Google Scholar. Publications from 2020 onward were prioritized, while earlier seminal studies, methodological frameworks and regulatory documents were included when relevant. Evidence was synthesized across AI-based resistance prediction, antimicrobial stewardship, digital microbiology and bioengineering technologies. Results: AI and machine-learning approaches showed promising performance in patient-level resistance prediction, pathogen-level susceptibility prediction and antimicrobial stewardship. For example, model discrimination reached an AUROC of 0.936 for carbapenem-resistant Klebsiella pneumoniae prediction, while model-guided empirical therapy in Enterobacterales bloodstream infections could have increased active beta-lactam therapy from 70% to 79%. However, most evidence remains retrospective and single-centre, with limited external or prospective validation. Conclusions: AI has considerable potential to support AMR prediction and antimicrobial stewardship, but current evidence primarily demonstrates technical feasibility rather than established clinical effectiveness. Broader implementation will require rigorous validation, integration into clinical workflows, continuous monitoring and demonstration of clinical benefit. Full article

Antimicrobial resistance (AMR) is one of the main public health problems that also affects environmental ecosystems. Sinkholes are understudied groundwater ecosystems that may act as reservoirs and dissemination routes for AMR. This study evaluated the composition, distribution, and antimicrobial resistance profiles of culturable ampicillin-resistant Gram-negative bacteria recovered from sinkholes of the Yucatán Peninsula, Mexico. Water samples were collected from 27 sinkholes during dry and rainy seasons. The isolates were identified by MALDI-TOF MS and evaluated by broth microdilution. Representative E. coli isolates were analyzed by whole-genome sequencing. A total of 193 ampicillin-resistant Gram-negative isolates were recovered. The most frequently recovered genera were Enterobacter, Klebsiella, and Escherichia, which were detected across all hydrogeological zones. Resistance to cefotaxime, levofloxacin, gentamicin, and tetracycline was detected among several bacterial genera. Opportunistic bacterial species associated with healthcare-associated infections, including K. pneumoniae, A. baumannii, and P. aeruginosa, were also identified. Genomic analysis of 19 E. coli isolates revealed resistance determinants associated with multiple antimicrobial classes and a diverse population structure dominated by phylogroup B1. These findings show that the Ring of Cenotes aquifer harbors diverse populations of culturable ampicillin-resistant Gram-negative bacteria and emphasize the importance of groundwater ecosystems as environmental reservoirs of AMR. Full article

A multicentre, laboratory-based analysis was conducted on aggregated data from 23 hospitals across Colombia. Of 1761 fungal isolates identified, 1642 were yeasts and constitute the focus of this study. Isolates were identified using the VITEK^®2 system, with confirmatory identification by MALDI-TOF-MS for a subset. Antifungal susceptibility testing for fluconazole, voriconazole, amphotericin B, and the echinocandins was performed on Candida albicans, C. parapsilosis, and C. tropicalis. Data were stratified by clinical service: adult ICU, adult wards, paediatric ICU, neonatal ICU, and paediatric wards. Temporal trends were assessed using the Cochran–Armitage test. The most prevalent species were C. albicans (42%), C. parapsilosis (24%), C. tropicalis (11%), C. glabrata (7%), and C. auris (3%). C. albicans predominated in adult services, whereas C. parapsilosis was the leading pathogen across paediatric settings. Among species with validated breakpoints, the overall fluconazole resistance rate was 19%, driven primarily by C. parapsilosis (35%, exceeding 40% in some clinical services). Non-wild-type to voriconazole and amphotericin B was low (<5%), and echinocandin resistance was exceedingly rare. The substantial fluconazole resistance driven by C. parapsilosis, together with the emergence of C. auris, underscores the urgent need for sustained surveillance and species-directed antifungal stewardship programmes. Full article

The emergence of antimicrobial resistance among ESKAPE pathogens represents a major One Health challenge, yet several clinically relevant members of this group remain underrecognized in companion animals because of diagnostic limitations and research bias. This review critically evaluates current evidence on neglected ESKAPE pathogens in dogs and cats, with particular emphasis on diagnostic blind spots, antimicrobial resistance, zoonotic implications, and the potential of phytotherapeutic strategies. A structured literature search of PubMed, Scopus, and Web of Science, complemented by reports from international health organizations, was conducted to identify studies addressing pathogen occurrence, resistance mechanisms, transmission pathways, and plant-derived antimicrobial compounds. The available evidence indicates that organisms such as the Enterobacter cloacae complex, Stenotrophomonas maltophilia, Enterococcus faecium, and Acinetobacter baumannii remain substantially underinvestigated despite their clinical relevance and multidrug-resistant phenotypes. Advanced diagnostic approaches, including MALDI-TOF MS and whole-genome sequencing, together with integrated One Health surveillance, may improve their detection and epidemiological characterization. Current phytotherapeutic research demonstrates promising antibacterial, antibiofilm, and antibiotic-potentiating activities of plant-derived compounds but remains largely focused on well-characterized pathogens. Targeted investigation of neglected ESKAPE pathogens using chemically characterized plant extracts and clinically relevant veterinary isolates may support the development of complementary antimicrobial strategies and strengthen antimicrobial stewardship within the One Health framework. Full article

Ziziphus jujuba Mill. is an important economic tree species in China with nutritional, ecological and ornamental values, and its fruits show abundant variations in size and shape. Phytohormones regulate fruit morphogenesis, yet the spatial distribution characteristics of endogenous phytohormones in jujube fruits with different shapes remain unclear. In this study, matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) was applied to explore the spatial distribution patterns of phytohormones in round, constricted and long jujube fruits. The results indicated that phytohormones were uniformly distributed in the flesh and pericarp of round and constricted fruits. Certain auxins and gibberellins were undetectable in the outer pericarp of long fruits, while one cytokinin was predominantly accumulated at the fruit base. The differential distribution of phytohormones is likely a potential factor triggering jujube fruit morphological differentiation. This study clarifies the spatial variation in endogenous phytohormones, helping elucidate the regulatory mechanism of jujube fruit shape. Full article

The present study investigated the chemical composition, antimicrobial, insecticidal, and food preservation potential of Ligusticum chuanxiong CO₂ oil (LCCO) standardised to a ligustilide content of ≥35%. The volatile composition of LCCO was characterised by GC-MS and found to be dominated by cis-ligustilide (63.3%), senkyunolide (15.8%), 3-butylidenephthalide (5.4%), and trans-neocnidilide (4.9%). In vitro antimicrobial activity was evaluated by disc diffusion and broth microdilution against six bacterial and five yeast reference strains. The largest inhibition zones were observed against Enterococcus faecalis (14.33 mm) and Staphylococcus aureus (13.67 mm). MIC₅₀ values ranged from 0.064 mg/mL (Yersinia enterocolitica) to 3.492 mg/mL (Candida tropicalis), while MIC₉₀ values ranged from 0.151 to 3.800 mg/mL. In situ vapour-phase antimicrobial activity was evaluated on pear, banana, white radish, and carrot at concentrations of 62.5–500 µL/L, demonstrating a clear concentration-dependent inhibitory effect across all tested food matrices and microorganisms. Insecticidal activity against Callosobruchus maculatus and Megabruchidius dorsalis was confirmed under fumigation conditions, with LC₅₀ values of 17.50% and 20.99% and LC90 values of 83.10% and 87.60%, respectively. The effect of LCCO, applied alone and in combination with vacuum packaging, on the microbiological quality of fresh white radish was evaluated over 28 days of refrigerated storage at 4 °C. The combined treatment resulted in the lowest total viable count (2.75 log CFU/g) and coliform bacteria count (2.58 log CFU/g) on day 28. A total of 404 bacterial isolates were identified using MALDI-TOF MS Biotyper, comprising 22 species. Acinetobacter pittii was the predominant species (33%), followed by Pantoea agglomerans (7%) and Serratia nematodiphila (7%). No Pseudomonas species were recovered from the EO vacuum treatment. Overall, these findings demonstrate the potential of LCCO, particularly in combination with vacuum packaging, as a natural antimicrobial agent for the postharvest preservation of fresh white radish. Full article

Background/Objectives: Acinetobacter baumannii is a major cause of infections in Intensive Care Units (ICUs), driving mortality through high-level antimicrobial resistance. This study utilized whole-genome sequencing (WGS) to evaluate the phenotypic, genotypic and virulence features of carbapenem-resistant A. baumannii (CRAB), which has caused ventilator-associated pneumonia/tracheobronchitis (VAP/VAT) in the ICU of the University Hospital of Split, Croatia. Methods: Over 1 year, lower respiratory tract specimens from 79 VAP/VAT patients were analyzed. CRAB isolates were identified via MALDI-TOF MS and evaluated for antimicrobial susceptibility, and a representative subset underwent WGS and multilocus sequence typing (MLST). Results: Out of 106 specimens, 18 non-duplicate CRAB strains were isolated. Five isolates underwent genomic analysis, identifying two globally distributed, high-risk Pasteur lineages: ST2 and ST492. These lineages displayed distinct resistomes: ST2 carried bla_OXA-23 and bla_ADC-73, while ST492 harbored plasmid-borne bla_OXA-72 (Rep3-T1/AB082 cluster) and bla_ADC-30. All isolates shared aminoglycoside/macrolide-resistance genes, conserved efflux pumps, and virulence determinants (bau, bas, ent, bar) crucial for acinetobactin synthesis and respiratory colonization. Phylogenetic analysis confirmed regional circulation and genetic links to neighboring countries. Conclusions: This study highlights the evolutionary dynamics of endemic CRAB lineages in a Croatian ICU and their global dissemination, which poses a critical threat, demanding strict infection control and novel therapeutics. Full article