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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 -
Revista Argentina de Microbiologia 2023This is the first study of the genetic diversity of Moraxella spp. Isolates were detected in an Eye Hospital in the City of Buenos Aires. Due to the high frequency of...
This is the first study of the genetic diversity of Moraxella spp. Isolates were detected in an Eye Hospital in the City of Buenos Aires. Due to the high frequency of Moraxella spp. observed in corneal abscesses, we decided to validate their identification at the species level, determine their drug susceptibility and perform molecular subtyping. Seventeen (17) isolates obtained from corneal abscesses were evaluated. The identification was carried out using a combination of biochemical tests and MALDI-TOF mass spectrometry. Of these isolates, 88.2% were identified as Moraxella lacunata, and 11.8% as Moraxella nonliquefaciens. Molecular subtyping was performed using the pulsed-field gel electrophoresis (PFGE) technique. All isolates were typable and thirteen digestion patterns were identified. Based on the obtained results, the PFGE technique using the SmaI enzyme can be used for epidemiological studies of strains of these species.
Topics: Humans; Abscess; Moraxella; Electrophoresis, Gel, Pulsed-Field; Genetic Variation
PubMed: 35915013
DOI: 10.1016/j.ram.2022.03.004 -
Cureus Jun 2022Eculizumab, first-line therapy for paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS), has infectious side effects in addition to... (Review)
Review
Eculizumab, first-line therapy for paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS), has infectious side effects in addition to its therapeutic benefits. This study aims to discuss the mechanism of development of infections, prevention, and timely treatment to prevent complications such as septic shock and mortality. The study was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist and reporting guidelines for systematic review. Inclusion and exclusion criteria were determined. A total of 10 research papers were extracted after exploring Pubmed and Google Scholar from 2001 to 2021. The New Castle Ottawa Questionnaire for non-randomized clinical trials and the National Institutes of Health (NIH) quality assessment tool for case reports and case series were used to assess the risk of bias. The studies included in this systematic review describe infections with , , unusual species, , and . The main goal of this review is to impress upon the seriousness of the infectious complications associated with eculizumab. Health care providers should maintain a high index of suspicion for early identification and treatment.
PubMed: 35784997
DOI: 10.7759/cureus.25640 -
Animals : An Open Access Journal From... Mar 2022From a clinical point of view, knowledge of the commensal microbial flora of the conjunctival sac in healthy individuals proves to be of great importance. The aim of...
From a clinical point of view, knowledge of the commensal microbial flora of the conjunctival sac in healthy individuals proves to be of great importance. The aim of this study was to assess the presence and the composition of normal ocular microflora of healthy donkeys. Fourteen clinically healthy donkeys () participated in the study. After prior ophthalmological examination, which showed no abnormalities, a conjunctival swab was taken from each donkey from the right and left eye. Species-specific identification was based on a morphological assessment of bacterial colonies stained with the Gram technique, as well as on biochemical properties and the disk-diffusion method. Around 82% of samples were positive for bacteria cultivation; was the most prevalently detected species, followed by . In conclusion, our study made it possible to determine the commensal flora of the conjunctival sac in donkeys. The obtained results also showed discrepancies in the composition of the conjunctival sac flora of donkeys and horses, despite the geographical proximity of performed studies. Knowledge of the commensal conjunctival flora of donkeys is of great clinical importance due to their greater exposure to corneal damage and infections than horses.
PubMed: 35327153
DOI: 10.3390/ani12060756 -
Clinical Medicine Insights. Pediatrics 2021, a low-virulence Gram-negative coccobacillus, is classically associated with conjunctivitis and upper respiratory tract infections; systemic infections such as sepsis...
, a low-virulence Gram-negative coccobacillus, is classically associated with conjunctivitis and upper respiratory tract infections; systemic infections such as sepsis have rarely been reported, especially in children. We describe a 28-month-old girl with atypical hemolytic uremic syndrome and stage II chronic kidney disease on long-term eculizumab therapy who presented with systemic inflammatory response syndrome and was found to have bloodstream infection. Eculizumab, a humanized monoclonal anti-C5 antibody, has been associated with susceptibility to infections with encapsulated bacteria, especially . This is the first report of an invasive bacterial infection with in a pediatric eculizumab recipient.
PubMed: 33613039
DOI: 10.1177/1179556521992367 -
Open Medicine (Warsaw, Poland) 2020() is a Gram-negative bacterium, which rarely causes serious infection. This is a rare case report of acute glomerulonephritis diagnosed by pathological findings in a...
() is a Gram-negative bacterium, which rarely causes serious infection. This is a rare case report of acute glomerulonephritis diagnosed by pathological findings in a child accompanied by infection. The patient showed hematuria, proteinuria and hyperkalemia requiring emergency hemodialysis. After hospitalization, bacteremia became apparent. Pathological findings showed an increase in glomerulus inflammatory cells and glomerular C3 deposition was observed in the renal tissue biopsy. Final diagnosis was endocapillary proliferative glomerulonephritis. Clinical reports of infection requiring emergency hemodialysis in children are rare. Previous reports have suggested that lowered immune competency with chronic kidney disease may be a risk factor associated with serious invasive cases of infection. However, detailed clinical laboratory data and pathological findings have not been identified in previous case reports. Our case directly indicated complement activity and acute glomerulonephritis with infection. Although there are various causes for acute glomerulonephritis, infection-related glomerulonephritis (IRGN) is an important concept. infection might have a potential risk for IRGN with dysregulation of complement activity leading to serious and invasive clinical conditions than previously considered.
PubMed: 33313415
DOI: 10.1515/med-2020-0234 -
European Journal of Clinical... Dec 2020We aimed to assess the prevalence, risk factors, and visual outcome of Moraxella keratitis. We retrospectively reviewed the medical charts of patients diagnosed with...
We aimed to assess the prevalence, risk factors, and visual outcome of Moraxella keratitis. We retrospectively reviewed the medical charts of patients diagnosed with Moraxella spp. keratitis at the Quinze-Vingts National Ophthalmology Hospital, Paris, France, between January 2016 and December 2018. Definitive microbiological identification was performed on archival strains using matrix-assisted laser desorption ionization time of flight coupled to mass spectrometry. One hundred one culture-proven cases of Moraxella keratitis were identified. The most common isolates were Moraxella lacunata (50%) and Moraxella nonliquefasciens (38%). Systemic predisposing factors, principally diabetes mellitus (13%) were identified in 28% of patients, and 87% of patients had ocular surface conditions, including blepharitis (25%), prior ocular surgery (21%), glaucoma (17%), exposure keratopathy (16%), and trauma (16%). Severely affected inpatients were treated empirically with fortified antibiotics including vancomycin, piperacillin, and gentamicin. The presence of hypopyon and being over the age of 60 years were associated with a poorer final visual acuity (p < 0.05). Adjuvant treatment, mostly amniotic membrane transplantation, was required for 31 eyes. The prognostic factors significantly associated with the need for adjuvant treatment were a larger infiltrate and hypoesthesia. The clinical features including ulcer healing, treatment duration, and infiltrate size were not different between Moraxella species. Keratitis caused by Moraxella spp. are rare in France but may threaten sight. The early identification of patients with a poor ocular surface, particularly those with neurotrophic keratopathy and anesthetic cornea, is crucial to prevent delayed healing of ulcers and the need for adjuvant treatment.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Female; Humans; Keratitis; Keratoplasty, Penetrating; Logistic Models; Male; Middle Aged; Moraxella; Moraxellaceae Infections; Paris; Retrospective Studies; Risk Factors; Visual Acuity; Young Adult
PubMed: 32648113
DOI: 10.1007/s10096-020-03985-7 -
Journal of the Pediatric Infectious... Mar 2021Moraxella lacunata is a rare coccobacillus associated with eye and upper respiratory tract infections. It may also have an affinity for bone and joint tissue. We report...
Moraxella lacunata is a rare coccobacillus associated with eye and upper respiratory tract infections. It may also have an affinity for bone and joint tissue. We report on 1 case of subacute osteomyelitis of the patella due to M. lacunata that presented as an osteolytic bone lesion in a child.
Topics: Child; Humans; Moraxella; Osteomyelitis
PubMed: 31830267
DOI: 10.1093/jpids/piz089