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Biology Dec 2023Keratitis (AK) is a severe corneal infection caused by the species of protozoa, potentially leading to permanent vision loss. AK requires prompt diagnosis and... (Review)
Review
Keratitis (AK) is a severe corneal infection caused by the species of protozoa, potentially leading to permanent vision loss. AK requires prompt diagnosis and treatment to mitigate vision impairment. Diagnosing AK is challenging due to overlapping symptoms with other corneal infections, and treatment is made complicated by the organism's dual forms and increasing virulence, and delayed diagnosis. In this review, new approaches in AK diagnostics and treatment within the last 5 years are discussed. The English-language literature on PubMed was reviewed using the search terms " keratitis" and "diagnosis" or "treatment" and focused on studies published between 2018 and 2023. Two hundred sixty-five publications were initially identified, of which eighty-seven met inclusion and exclusion criteria. This review highlights the findings of these studies. Notably, advances in PCR-based diagnostics may be clinically implemented in the near future, while antibody-based and machine-learning approaches hold promise for the future. Single-drug topical therapy (0.08% PHMB) may improve drug access and efficacy, while oral medication (i.e., miltefosine) may offer a treatment option for patients with recalcitrant disease.
PubMed: 38132315
DOI: 10.3390/biology12121489 -
Indian Journal of Ophthalmology Jan 2024To analyze the influence of infiltrate size, depth, and organism on the outcome of microbial keratitis.
PURPOSE
To analyze the influence of infiltrate size, depth, and organism on the outcome of microbial keratitis.
DESIGN
Retrospective comparative study.
METHODS
Medical records of patients with infective keratitis, who reported from January 2015 to December 2019 to a tertiary eye care center, were analyzed. Size and depth of ulcer at presentation were the factors used to group patients, and the influence on the outcome of the organism causing it was analyzed. Grouping was as follows: group A: ulcer size <6 mm/anterior to midstromal infiltrate, group B: ulcer < 6 mm/full-thickness infiltrate, group C: ulcer >6 mm/anterior to midstromal infiltrate, group D: ulcer > 6 mm/full-thickness infiltrate. Patients with viral keratitis or unidentified organism were excluded. Response to treatment and best-corrected visual acuity (BCVA) at the final follow-up were the outcome measures.
RESULTS
In the study, 1117/6276 patients were included, with 60.8% patients in group A. A significant improvement in visual acuity was noted in groups A/B compared to groups C/D. Group A had the best response to medical management, irrespective of the organism. Higher risk for surgery was noted in group C compared to group B, with group A as the reference. Overall resolution with medical treatment was noted in 70% miscellaneous keratitis, 64.8% bacterial keratitis, 64.3% mixed keratitis, 62.5% acanthamoeba keratitis, 52.6% fungal keratitis, and 12.1% Pythium keratitis. Bacteria and acanthamoeba responded better to medical management than fungal keratitis, whereas Pythium had the highest risk for surgery.
CONCLUSION
An interplay between virulence of the organism along with depth and size of the infiltrate determines the outcome of microbial keratitis.
Topics: Humans; Ulcer; Retrospective Studies; Corneal Ulcer; Eye Infections, Bacterial; Eye Infections, Fungal; Acanthamoeba Keratitis
PubMed: 38131568
DOI: 10.4103/IJO.IJO_1022_23 -
Journal of Ophthalmic Inflammation and... Dec 2023Ring infiltrates usually accompany numerous infectious and sterile ocular disorders. Nevertheless, systemic conditions, drugs toxicity and contact lens wear may present... (Review)
Review
OBJECTIVE
Ring infiltrates usually accompany numerous infectious and sterile ocular disorders. Nevertheless, systemic conditions, drugs toxicity and contact lens wear may present with corneal ring infiltrate in substantial part. Considering its detrimental effect on vision, detailed knowledge on etiology, pathophysiology, differential diagnosis, and management should be considered essential for every ophthalmologist.
METHODS
The PUBMED database was searched for "corneal ring infiltrate" and "ring infiltrate" phrases, "sterile corneal infiltrate" and "corneal infiltrate". We analyzed articles written in English on risk factors, pathophysiology, clinical manifestation, morphological features, ancillary tests (anterior-segment optical coherence tomography, corneal scraping, in vivo confocal microscopy), differential diagnosis and management of corneal ring infiltrate.
RESULTS
Available literature depicts multifactorial origin of corneal ring infiltrate. Dual immunological pathophysiology, involving both antibodies-dependent and -independent complement activation, is underlined. Furthermore, we found that the worldwide most prevalent among non-infectious and infectious ring infiltrates are ring infiltrates related to contact-lens wear and bacterial keratitis respectively. Despite low incidence of Acanthamoeba keratitis, it manifests with corneal ring infiltrate with the highest proportion of the affected patients (one third). However, similar ring infiltrate might appear as a first sign of general diseases manifestation and require targeted treatment. Every corneal ring infiltrate with compromised epithelium should be scraped and treat as an infectious infiltrate until not proven otherwise. Of note, microbiological ulcer might also lead to immunological ring and therefore require anti-inflammatory treatment.
CONCLUSION
Corneal ring infiltrate might be triggered not only by ocular infectious and non-infectious factors, but also by systemic conditions. Clinical assessment is crucial for empirical diagnosis. Furthermore, treatment is targeted towards the underlying condition but should begin with anti-infectious regimen until not proven otherwise.
PubMed: 38112842
DOI: 10.1186/s12348-023-00379-6 -
Frontiers in Microbiology 2023Since the discovery of the first "giant virus," particular attention has been paid toward isolating and culturing these large DNA viruses through spp. bait systems.... (Review)
Review
Since the discovery of the first "giant virus," particular attention has been paid toward isolating and culturing these large DNA viruses through spp. bait systems. While this method has allowed for the discovery of plenty novel viruses in the , environmental -omics-based analyses have shown that there is a wealth of diversity among this phylum, particularly in marine datasets. The prevalence of these viruses in metatranscriptomes points toward their ecological importance in nutrient turnover in our oceans and as such, in depth study into non-amoebal should be considered a focal point in viral ecology. In this review, we report on (née Aureococcus anophagefferens Virus), an algae-infecting virus of the . Current systems for study in the differ significantly from this virus and its relatives, and a litany of trade-offs within physiology, coding potential, and ecology compared to these other viruses reveal the importance of . Herein, we review the research that has been performed on this virus as well as its potential as a model system for algal-virus interactions.
PubMed: 38098665
DOI: 10.3389/fmicb.2023.1284617 -
Microbiology Spectrum Jan 2024At the National Cheng Kung University Hospital, numerous cases of amoebic keratitis had been identified with concurrent bacterial infections. Among these bacterial...
At the National Cheng Kung University Hospital, numerous cases of amoebic keratitis had been identified with concurrent bacterial infections. Among these bacterial coinfections, accounted for 50% of the reported cases. However, the impact of pathogenic bacteria on amoeba-induced corneal damage remains unclear. In our study, we successfully demonstrated that accumulated on the surface and caused more severe corneal damage. We also indicated that the exposure of to amoeba-soluble antigens enhanced its adhesion ability, promoted biofilm formation, and led to more severe corneal cell damage. These findings significantly contributed to our understanding of the risk associated with coinfection in the progression of amoeba keratitis.
Topics: Humans; Pseudomonas aeruginosa; Coinfection; Cornea; Keratitis; Corneal Injuries
PubMed: 38095463
DOI: 10.1128/spectrum.02683-23 -
ELife Dec 2023Identifying virulence-critical genes from pathogens is often limited by functional redundancy. To rapidly interrogate the contributions of combinations of genes to a...
Identifying virulence-critical genes from pathogens is often limited by functional redundancy. To rapidly interrogate the contributions of combinations of genes to a biological outcome, we have developed a ltiplex, andomized RISPR nterference equencing (MuRCiS) approach. At its center is a new method for the randomized self-assembly of CRISPR arrays from synthetic oligonucleotide pairs. When paired with PacBio long-read sequencing, MuRCiS allowed for near-comprehensive interrogation of all pairwise combinations of a group of 44 virulence genes encoding highly conserved transmembrane proteins for their role in pathogenesis. Both amoeba and human macrophages were challenged with bearing the pooled CRISPR array libraries, leading to the identification of several new virulence-critical combinations of genes. and were particularly fascinating for their apparent redundant functions during human macrophage infection, while alone was essential for virulence in the amoeban host . Thus, MuRCiS provides a method for rapid genetic examination of even large groups of redundant genes, setting the stage for application of this technology to a variety of biological contexts and organisms.
Topics: Humans; Macrophages; Legionella pneumophila; Acanthamoeba castellanii; Virulence; Legionnaires' Disease; Bacterial Proteins
PubMed: 38095310
DOI: 10.7554/eLife.86903 -
Scientific Reports Dec 2023Phthalates constitute a family of anthropogenic chemicals developed to be used in the manufacture of plastics, solvents, and personal care products. Their dispersion and...
Phthalates constitute a family of anthropogenic chemicals developed to be used in the manufacture of plastics, solvents, and personal care products. Their dispersion and accumulation in many environments can occur at all stages of their use (from synthesis to recycling). However, many phthalates together with other accumulated engineered chemicals have been shown to interfere with hormone activities. These compounds are also in close contact with microorganisms that are free-living, in biofilms or in microbiota, within multicellular organisms. Herein, the activity of several phthalates and their substitutes were investigated on the opportunistic pathogen Legionella pneumophila, an aquatic microbe that can infect humans. Beside showing the toxicity of some phthalates, data suggested that Acetyl tributyl citrate (ATBC) and DBP (Di-n-butyl phthalate) at environmental doses (i.e. 10 M and 10 M) can modulate Legionella behavior in terms of motility, biofilm formation and response to antibiotics. A dose of 10 M mostly induced adverse effects for the bacteria, in contrast to a dose of 10 M. No perturbation of virulence towards Acanthamoeba castellanii was recorded. These behavioral alterations suggest that L. pneumophila is able to sense ATBC and DBP, in a cross-talk that either mimics the response to a native ligand, or dysregulates its physiology.
Topics: Humans; Legionella pneumophila; Legionella; Phthalic Acids; Biofilms
PubMed: 38092873
DOI: 10.1038/s41598-023-49426-1 -
Annals of Dermatology Nov 2023A 62-year-old man with multiple myeloma visited our clinic with multiple painful erythematous to purpuric nodules on his whole body. He received a skin biopsy which...
A 62-year-old man with multiple myeloma visited our clinic with multiple painful erythematous to purpuric nodules on his whole body. He received a skin biopsy which showed septal and lobular inflammation with vasculitis, and multiple amoebic organisms were found. Polymerase chain reaction and culture were performed and an infection was diagnosed. This is the first report on cutaneous acanthamoebiasis caused by , suggesting that should be regarded as a clinical pathogen that can cause ocular as well as disseminated infection.
PubMed: 38061721
DOI: 10.5021/ad.21.293 -
Frontiers in Physiology 2023Having characterized actin from (Weihing and Korn, Biochemistry, 1971, 10, 590-600) and knowing that myosin had been isolated from the slime mold (Hatano and Tazawa,... (Review)
Review
Having characterized actin from (Weihing and Korn, Biochemistry, 1971, 10, 590-600) and knowing that myosin had been isolated from the slime mold (Hatano and Tazawa, Biochim. Biophys. Acta, 1968, 154, 507-519; Adelman and Taylor, Biochemistry, 1969, 8, 4976-4988), we set out in 1969 to find myosin in . We used K-EDTA-ATPase activity to assay myosin, because it is a unique feature of muscle myosins. After slightly less than 3 years, we purified a K-EDTA ATPase that interacted with actin. Actin filaments stimulated the Mg-ATPase activity of the crude enzyme, but this was lost with further purification. Recombining fractions from the column where this activity was lost revealed a "cofactor" that allowed actin filaments to stimulate the Mg-ATPase of the purified enzyme. The small size of the heavy chain and physical properties of the purified myosin were unprecedented, so many were skeptical, assuming that our myosin was a proteolytic fragment of a larger myosin similar to muscle or myosin. Subsequently our laboratories confirmed that myosin-I is a novel unconventional myosin that interacts with membrane lipids (Adams and Pollard, Nature, 1989, 340 (6234), 565-568) and that the cofactor is a myosin heavy chain kinase (Maruta and Korn, J. Biol. Chem., 1977, 252, 8329-8332). Phylogenetic analysis (Odronitz and Kollmar, Genome Biology, 2007, 8, R196) later established that class I myosin was the first myosin to appear during the evolution of eukaryotes.
PubMed: 38046947
DOI: 10.3389/fphys.2023.1324623 -
Cureus Nov 2023keratitis is a potentially sight-threatening infection of the cornea that can lead to blindness. Over the past few decades, there has been a rise in the reported cases...
keratitis is a potentially sight-threatening infection of the cornea that can lead to blindness. Over the past few decades, there has been a rise in the reported cases worldwide, which is in line with the increase of contact lens wearers. Here, we present three cases of keratitis with different outcomes.
PubMed: 38046722
DOI: 10.7759/cureus.48129