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Middle East African Journal of... 2019Natural honey in spite of its usefulness is known to contain certain microorganisms. In the present study, we describe a case of after using topical honey administered...
Natural honey in spite of its usefulness is known to contain certain microorganisms. In the present study, we describe a case of after using topical honey administered by a traditional medicine therapist. A 32-year-old male came with red eye and blurred vision. The pain and other symptoms became more severe after the 1st week, with appearance of radial perineuritis at the cornea. A repeated interview revealed that 1 week before appearance of ocular symptoms, the patient had instilled a drop of natural honey in his left eye. Confocal microscopic cornea imaging demonstrated cyst and trophozoite of in the corneal stroma.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Adult; Honey; Humans; Male; Vision Disorders
PubMed: 32153338
DOI: 10.4103/meajo.MEAJO_56_18 -
Journal of Ophthalmic & Vision Research 2020To determine the causative organisms and associated risk factors for infectious keratitis in South Texas. (Review)
Review
PURPOSE
To determine the causative organisms and associated risk factors for infectious keratitis in South Texas.
METHODS
This retrospective study was performed at a tertiary teaching hospital system in South Texas. Medical records of all patients who presented with infectious keratitis from 2012 to 2018 were reviewed. Only patients with culture-proven bacterial, fungal, and keratitis were included.
RESULTS
In total, 182 eyes of 181 patients had culture-proven bacterial, fungal, or keratitis. The age of patients ranged from 3 to 93 years, with a mean of 48.3 20.8 years. The most common etiologic agent was bacteria, with 173 bacterial cultures (95.1%) recovered, followed by 13 fungal cultures (7.1%), and 3 cultures (1.6%). Of the 218 bacterial isolates, coagulase-negative was the most common (25.7%), followed by (23.4%), (11.0%), and (7.8%). was the most common fungal isolate (46.2%). The most common risk factors for infectious keratitis included contact lens wear (32.4%), underlying corneal disease (17.6%), trauma (14.3%), and ocular surface disease (13.7%).
CONCLUSIONS
Bacteria are the most common cause of infectious keratitis in this patient population, with coagulase-negative and as the most common isolates. The prevalence of culture-positive fungal keratitis is significantly lower than that of bacterial keratitis. Contact lens wear is the most common risk factor associated with infectious keratitis in South Texas.
PubMed: 32308946
DOI: 10.18502/jovr.v15i2.6729 -
The Ocular Surface Apr 2010Acanthamoeba keratitis (AK) is a serious infection of the cornea. At present, diagnosis of the disease is not straightforward and treatment is very demanding. While... (Review)
Review
Acanthamoeba keratitis (AK) is a serious infection of the cornea. At present, diagnosis of the disease is not straightforward and treatment is very demanding. While contact lens wear is the leading risk factor for A K, Acanthamoeba parasites are increasingly recognized as an important cause of keratitis in non-contact lens wearers. The first critical step in the pathogenesis of infection is the adhesion of the microbe to the surface of the host tissues. Acanthamoebae express a major virulence protein, the mannose-binding protein (MBP), which mediates the adhesion of amoebae to the surface of the cornea. The MBP is a transmembrane protein with characteristics of a typical cell surface receptor. Subsequent to the MBP-mediated adhesion to host cells, the amoebae produce a contact-dependent metalloproteinase and several contact-independent serine proteinases. These proteinases work in concert to produce a potent cytopathic effect (CPE ) involving killing of the host cells, degradation of epithelial basement membrane and underlying stromal matrix, and penetration into the deeper layers of the cornea. In the hamster animal model, oral immunization with the recombinant MBP protects against AK, and this protection is associated with an increased level of anti-MBP IgA in tears of protected animals. Normal human tear fluid contains IgA antibodies against Acanthamoeba MBP that is likely to provide protection by inhibiting the adhesion of parasites to host cells. Indeed, in in vitro CPE assays, even a low concentration of tears (10 microL of undiluted tears per milliliter of media) almost completely inhibits Acanthamoeba-induced CPE . In addition to adherence-inhibiting, IgA-mediated protection, human tears also contain IgA-independent factors that provide protection against Acanthamoeba-induced CPE by inhibiting the activity of cytotoxic proteinases. Characterization of the CPE-inhibitory factors of human tears should lead to a better understanding of the mechanism by which the tissues of the host resist the infection and also help decode circumstances that predispose to Acanthamoeba infections.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Animals; Cell Adhesion; Cornea; Humans; Mannose-Binding Lectin; Protozoan Proteins
PubMed: 20427010
DOI: 10.1016/s1542-0124(12)70071-x -
PloS One 2022Contact lens usage has contributed to increased incidence rates of Acanthamoeba keratitis (AK), a serious corneal infection that can lead to blindness. Since symptoms...
Contact lens usage has contributed to increased incidence rates of Acanthamoeba keratitis (AK), a serious corneal infection that can lead to blindness. Since symptoms associated with AK closely resemble those incurred by bacterial or fungal keratitis, developing a diagnostic method enabling rapid detection with a high degree of Acanthamoeba-specificity would be beneficial. Here, we produced a polyclonal antibody targeting the carboxylesterase (CE) superfamily protein secreted by the pathogenic Acanthamoeba and evaluated its diagnostic potential. Western blot analysis revealed that the CE antibody specifically interacts with the cell lysates and conditioned media of pathogenic Acanthamoeba, which were not observed from the cell lysates and conditioned media of human corneal epithelial (HCE) cells, Fusarium solani, Staphylococcus aureus, and Pseudomonas aeruginosa. High titers of A. castellanii-specific antibody production were confirmed sera of immunized mice via ELISA, and these antibodies were capable of detecting A. castellanii from the cell lysates and their conditioned media. The specificity of the CE antibody was further confirmed on A. castellanii trophozoites and cysts co-cultured with HCE cells, F. solani, S. aureus, and P. aeruginosa using immunocytochemistry. Additionally, the CE antibody produced in this study successfully interacted with 7 different Acanthamoeba species. Our findings demonstrate that the polyclonal CE antibody specifically detects multiple species belong to the genus Acanthamoeba, thus highlighting its potential as AK diagnostic tool.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Animals; Antibodies, Protozoan; Antibody Specificity; Carboxylesterase; Cell Line; Cells, Cultured; Contact Lenses; Culture Media, Conditioned; Early Diagnosis; Epithelial Cells; Epithelium, Corneal; Humans; Immunization; Male; Mice; Protozoan Proteins
PubMed: 34986189
DOI: 10.1371/journal.pone.0262223 -
Expert Review of Anti-infective Therapy Nov 2021: encompasses several species of free-living ameba encountered commonly throughout the environment. Unfortunately, these species of ameba can cause opportunistic...
: encompasses several species of free-living ameba encountered commonly throughout the environment. Unfortunately, these species of ameba can cause opportunistic infections that result in keratitis, granulomatous amebic encephalitis, and occasionally systemic infection.: This review discusses relevant literature found through PubMed and Google scholar published as of January 2021. The review summarizes current common keratitis treatments, drug discovery methodologies available for screening potential anti- compounds, and the anti- activity of various azole antifungal agents.: While several biguanide and diamidine antimicrobial agents are available to clinicians to effectively treat keratitis, no singular treatment can effectively treat every keratitis case.Efforts to identify new anti-Acanthamoeba agents include trophozoite cell viability assays, which are amenable to high-throughput screening. Cysticidal assays remain largely manual and would benefit from further automation development. Additionally, the existing literature on the effectiveness of various azole antifungal agents for treating keratitis is incomplete or contradictory, suggesting the need for a systematic review of all azoles against different pathogenic strains.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Amebicides; Azoles; Drug Evaluation, Preclinical; Humans
PubMed: 33929276
DOI: 10.1080/14787210.2021.1924673 -
Cornea Apr 2022The purpose of this study was to characterize rates of opioid prescription for different ulcerative keratitis types.
PURPOSE
The purpose of this study was to characterize rates of opioid prescription for different ulcerative keratitis types.
METHODS
This cohort study included patients diagnosed with ulcerative keratitis according to the University of Michigan electronic health record data between September 1, 2014 and December 22, 2020. Ulcerative keratitis was categorized by etiologic type (bacterial, fungal, viral, acanthamoeba, inflammatory, polymicrobial, or unspecified) using rule-based data classification that accounted for billing diagnosis code, antimicrobial or antiinflammatory medications prescribed, laboratory results, and manual chart review. Opioid prescriptions were converted to morphine milligram equivalent and summed over 90 days from diagnosis. Opioid prescription rate and amount were compared between ulcerative keratitis types.
RESULTS
Of 3322 patients with ulcerative keratitis, 173 (5.2%) were prescribed at least 1 opioid for pain management within 90 days of diagnosis. More patients with acanthamoeba (32.4%), fungal (21.1%), and polymicrobial (25.0%) keratitis were treated with opioids compared with bacterial (6.7%), unspecified (2.9%), or viral (1.8%) keratitis (all Bonferroni adjusted P < 0.05). For the 173 patients who were prescribed opioids, a total of 353 prescriptions were given within 90 days of diagnosis, with half given within the first week after diagnosis. The quantity of opioid prescribed within 90 days from diagnosis was not significantly different between ulcerative keratitis types (P = 0.6559). Morphine milligram equivalent units prescribed ranged from 97.5 for acanthamoeba keratitis to 112.5 for fungal keratitis.
CONCLUSIONS
The type of ulcerative keratitis may influence the opioid prescription rate. Providers can better serve patients needing opioids for pain management through improved characterization of pain and development of more tailored pain management regimens.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Analgesics, Opioid; Child; Child, Preschool; Corneal Ulcer; Drug Prescriptions; Eye Pain; Female; Humans; Infant; Infant, Newborn; Male; Middle Aged; Pain Management; Practice Patterns, Physicians'; Retrospective Studies
PubMed: 34620771
DOI: 10.1097/ICO.0000000000002893 -
Central-European Journal of Immunology 2020Acanthamoeba is a free-living protist pathogen, which is present in every place on Earth. 50 to 100 percent of the adult population has serum antibodies, specific for... (Review)
Review
Acanthamoeba is a free-living protist pathogen, which is present in every place on Earth. 50 to 100 percent of the adult population has serum antibodies, specific for Acanthamoeba antigens. Acanthamoeba is an etiological agent of keratitis and encephalitis diagnosed in human. Acanthamoeba keratitis occurs in healthy persons and may lead to visual impairment and blindness, because corneal infection with this parasite fails to induce cell-mediated immune response due to the absence of resident antigen-presenting cells in the cornea. Systemic immunization with Acanthamoeba antigens induces Th1 cell-mediated immunity and serum IgG antibody, but do not prevent the development of keratitis. Immunization via mucosal surfaces stimulates IgA antibodies in tears and protects against the development of keratitis. Amoebae feed mainly on bacteria, fungi, and algae. By transferring intracellular bacteria, amoeba contributes to the spread of diseases dangerous to humans. Some microorganisms have evolved to become resistant to protist, since they are not internalized or able to survive, grow, and exit free-living protists after internalization. In many cases, the bacteria inside living amoebae survive longer, and multiply better, showing higher virulence. There is a hypothesis, which assumes that Acanthamoeba and symbiontic bacteria survive and multiply better in moist soil, rich in nitrogen compounds, particularly in the vicinity of the root systems of Alnus glutinosa, infected with nitrogen-fixing bacteria Frankia alni. Impact of soil environment created by nitrogen-fixing bacterium Frankia alni on specific relations between protists Acanthamoeba and highly pathogenic bacteria strains in Alnus glutinosa habitats in Poland continue to be established.
PubMed: 33456336
DOI: 10.5114/ceji.2020.97667 -
Pathogens (Basel, Switzerland) Feb 2024keratitis (AK) is a severe, rare protozoal infection of the cornea. can survive in diverse habitats and at extreme temperatures. AK is mostly seen in contact lens... (Review)
Review
keratitis (AK) is a severe, rare protozoal infection of the cornea. can survive in diverse habitats and at extreme temperatures. AK is mostly seen in contact lens wearers whose lenses have become contaminated or who have a history of water exposure, and in those without contact lens wear who have experienced recent eye trauma involving contaminated soil or water. Infection usually results in severe eye pain, photophobia, inflammation, and corneal epithelial defects. The pathophysiology of this infection is multifactorial, including the production of cytotoxic proteases by that degrades the corneal epithelial basement membrane and induces the death of ocular surface cells, resulting in degradation of the collagen-rich corneal stroma. AK can be prevented by avoiding risk factors, which includes avoiding water contact, such as swimming or showering in contact lenses, and wearing protective goggles when working on the land. AK is mostly treated with an antimicrobial therapy of biguanides alone or in combination with diaminidines, although the commercial availability of these medicines is variable. Other than anti-amoeba therapies, targeting host immune pathways in disease may lead to the development of vaccines or antibody therapeutics which could transform the management of AK.
PubMed: 38392880
DOI: 10.3390/pathogens13020142 -
Veterinary Journal (London, England :... Aug 2021Pathogenic free-living amoebae, most notably Acanthamoeba spp., are important pathogens of the human cornea. The importance of infection with free-living amoebae in cats...
Pathogenic free-living amoebae, most notably Acanthamoeba spp., are important pathogens of the human cornea. The importance of infection with free-living amoebae in cats with keratitis is currently unclear. The aim of this study was to determine the frequency of amoeba detection in corneas of cats with naturally-acquired keratitis and in the ocular surface microflora of cats without ocular disease. Clinical ophthalmic and in vivo corneal confocal microscopic examinations were performed on 60 cats with keratitis. Corneal scrapings were analyzed by amoeba culture; cytological evaluation; and Acanthamoeba, Hartmannella, and Vahlkampfia PCR assays. Following ophthalmic examination, conjunctival specimens collected from 60 cats without clinically apparent ocular disease were analyzed similarly. In one cat with ulcerative keratitis, amoeba cysts and trophozoites were detected by in vivo corneal confocal microscopy; an Acanthamoeba sp. was isolated from corneal specimens and detected by Acanthamoeba PCR assay; and suppurative corneal inflammation was present cytologically. An Acanthamoeba sp. was isolated from conjunctival specimens from one cat without clinically apparent ocular disease, but with suppurative inflammation demonstrated cytologically. Both Acanthamoeba isolates belonged to the T4 genotype. Naegleria-like amoebae were isolated in samples from two cats with keratitis and seven cats without clinical ocular disease, but amoebae were not detected by the other assays in these samples. Amoeba detection by culture was significantly (P = 0.01) associated with cytologically diagnosed corneoconjunctival inflammation. This study identified naturally-acquired Acanthamoeba keratitis in cats. Detection of Naegleria-like amoebae in samples from cats with and without keratitis is of uncertain pathological significance.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Amoeba; Animals; Cat Diseases; Cats; Cornea; Female; Keratitis; Male
PubMed: 34182073
DOI: 10.1016/j.tvjl.2021.105712 -
Pathogens (Basel, Switzerland) Dec 2022are amphizoic amoeba majorly responsible for causing keratitis (AK) and Granulomatous amoebic encephalitis (GAE). Despite its ubiquitous nature, the frequency of...
BACKGROUND
are amphizoic amoeba majorly responsible for causing keratitis (AK) and Granulomatous amoebic encephalitis (GAE). Despite its ubiquitous nature, the frequency of infections is not high, probably due to the existence of non-pathogenic isolates. The whole-genome sequencing and an annotated genome assembly can unravel the biological functions and help in identifying probable genes related to pathogenicity.
METHODS
Illumina and Nanopore sequencing were performed for keratitis, encephalitis, and non-pathogenic environmental isolates. Hybrid assembly was prepared for the AK and GAE isolates, while only the Illumina reads were utilized for a non-pathogenic environmental isolate. Protein coding genes were identified using the GeneMark-ES program and BLASTx module of Diamond used for gene prediction. Additionally, the Kyoto Encyclopedia of Genes and Genomes annotation and cluster of orthologous group's annotation using RPS-blast against the CDD database was performed. The subsequent data analysis and validation will help identify probable pathogenic genes.
RESULTS
The genome assemblies of 9.67, 8.34, and 8.89 GBs were reported for GAE, AK, and non-pathogenic isolate, respectively. KEGG reported 22,946 in GAE, 24,231 in keratitis, and 9367 genes in the environmental isolate. The COG annotation revealed 3232 in GAE, 3403 in keratitis, and 1314 genes in the non-pathogenic isolate.
CONCLUSION
The present study has attempted to generate de novo hybrid genome assemblies of that would help decode the genome of free-living amoeba and will provide genomic data for a better understanding of virulence-related factors.
PubMed: 36558892
DOI: 10.3390/pathogens11121558