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Scientific Reports Apr 2024Diabetes mellitus is recognized as a major predisposing factor for Moraxella keratitis. However, how diabetes mellitus contributes to Moraxella keratitis remains...
Diabetes mellitus is recognized as a major predisposing factor for Moraxella keratitis. However, how diabetes mellitus contributes to Moraxella keratitis remains unclear. In this study, we examined Moraxella keratitis; based on the findings, we investigated the impact of advanced glycation end products (AGEs) deposition in the cornea of individuals with diabetic mellitus on the adhesion of Moraxella isolates to the cornea. A retrospective analysis of 27 culture-proven cases of Moraxella keratitis at Ehime University Hospital (March 2006 to February 2022) was performed. Moraxella isolates were identified using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Among the patients, 30.4% had diabetes mellitus and 22.2% had the predominant ocular condition of using steroid eye drops. The species identified were Moraxella nonliquefaciens in 59.3% and Moraxella lacunata in 40.7% of patients. To investigate the underlying mechanisms, we assessed the effects of M. nonliquefaciens adherence to simian virus 40-immortalized human corneal epithelial cells (HCECs) with or without AGEs. The results demonstrated the number of M. nonliquefaciens adhering to HCECs was significantly increased by adding AGEs compared with that in controls (p < 0.01). Furthermore, in the corneas of streptozotocin-induced diabetic C57BL/6 mice treated with or without pyridoxamine, an AGE inhibitor, the number of M. nonliquefaciens adhering to the corneas of diabetic mice was significantly reduced by pyridoxamine treatment (p < 0.05). In conclusion, the development of Moraxella keratitis may be significantly influenced by the deposition of AGEs on the corneal epithelium of patients with diabetes mellitus.
Topics: Humans; Animals; Mice; Retrospective Studies; Diabetes Mellitus, Experimental; Pyridoxamine; Mice, Inbred C57BL; Keratitis; Moraxella; Cornea; Glycation End Products, Advanced
PubMed: 38580798
DOI: 10.1038/s41598-024-58659-7 -
Journal of Biomolecular Structure &... Apr 2024is an emerging gram-negative bacterium that is responsible for multiple nosocomial infections. The bacterium is evolving resistance to several antibiotics, and...
is an emerging gram-negative bacterium that is responsible for multiple nosocomial infections. The bacterium is evolving resistance to several antibiotics, and currently, no effective licensed vaccines are available, which warrants the search for new therapeutics. A multi-epitope-based vaccine has been designed for . The complete proteome of contains 10,110 core proteins. Subcellular localization analysis revealed the presence of five proteins in the extracellular matrix, while 19 proteins were predicted to be located in the outer membrane, and 21 proteins were predicted to be located in the periplasmic region. Only two proteins, the type VI secretion system tube protein (Hcp) and the transporter substrate-binding domain-containing protein, were selected for epitope prediction as they fulfilled all the criteria for being potential vaccine candidates. Shortlisted epitopes from the selected proteins were fused together using "GPGPG" linkers to overcome the limitations of single-epitope vaccines. Next, the cholera toxin-B adjuvant was attached to the peptide epitope using an EAAAK linker. Docking analysis was performed to examine the interaction between the vaccine and immune cell receptors, revealing robust intermolecular interactions and a stable binding conformation. Molecular dynamics simulation findings revealed no drastic changes in the binding conformation of complexes during the simulation period. The net binding free energy of vaccine-receptor complexes was estimated using the molecular mechanics energies combined with the Poisson-Boltzmann and surface area continuum solvation (MM-PBSA) method. The reported values were -586.38 kcal/mol, -283.74 kcal/mol, and -296.88 kcal/mol for the TLR-4-vaccine complex, MHC-I-vaccine complex, and MHC-II-vaccine complex, respectively. Furthermore, the molecular mechanics energies combined with the generalized Born and surface area continuum solvation (MM-GBSA) analysis predicted binding free energies of -596.69 kcal/mol, -287.39 kcal/mol, and -298.28 kcal/mol for the TLR-4-vaccine complex, MHC-I-vaccine complex, and MHC-II-vaccine complex, respectively. The theoretical vaccine design proposed in the study could potentially serve as a powerful therapeutic against targeted pathogens, subject to validation through experimental studies.Communicated by Ramaswamy H. Sarma.
Topics: Toll-Like Receptor 4; Epitopes; Molecular Dynamics Simulation; Bacterial Vaccines; Molecular Docking Simulation; Computational Biology; Epitopes, T-Lymphocyte; Vaccines, Subunit; Epitopes, B-Lymphocyte; Moraxella
PubMed: 37177816
DOI: 10.1080/07391102.2023.2212793 -
European Journal of Ophthalmology Jul 2023To evaluate the microbiota of culture negative Corneal Impression Membrane (CIM) microbial keratitis samples with the use of shotgun metagenomics analysis.
PURPOSE
To evaluate the microbiota of culture negative Corneal Impression Membrane (CIM) microbial keratitis samples with the use of shotgun metagenomics analysis.
METHODS
DNA of microbial keratitis samples were collected with CIM and extracted using the MasterPure™ Complete DNA and RNA Purification Kit (Epicentre). DNA was fragmented by sonication into fragments of 300 to 400 base pairs (bp) using Bioruptor® (Diagenode, Belgium) and then used as a template for library preparation. DNA libraries were sequenced on Illumina® HiSeq2500. The resulting reads were quality controlled, trimmed and mapped against the human reference genome. The unmapped reads were taxonomically classified using the Kraken software.
RESULTS
18 microbial keratitis samples were included in the study. was found in 5 samples while 6 samples showed the presence of viral infections. , , and were also identified as the presumed putative cause of the infection in 7 samples.
CONCLUSIONS
Shotgun sequencing can be used as a diagnostic tool in microbial keratitis samples. This diagnostic method expands the available tests to diagnose eye infections and could be clinically significant in culture negative samples.
Topics: Humans; Metagenomics; Eye Infections; Keratitis; DNA; Software
PubMed: 36617769
DOI: 10.1177/11206721221149077