In Vitro Amoebicidal Activity of Imidazolium Salts Against Trophozoites

INTRODUCTION

Several strains of the free-living genus Acanthamoeba can cause granulomatous amoebic encephalitis (GAE), a rare chronic and slowly progressive infection of the central nervous system (CNS), and Acanthamoeba keratitis (AK), a sight-threatening eye infectious disease. AK incidence has increased with the popularization of the contact lens wear and its treatment is currently limited and frequently unsuccessful. As imidazolium salts (IS), cationic imidazole derivatives, have promising antimicrobial potential.

MATERIALS AND METHODS

The present study evaluated the amoebicidal activity of four IS; 1-n-hexadecyl-3-methylimidazolium methanesulfonate (C₁₆MImMeS), chloride (C₁₆MImCl) and bis (triluoromethylsulfonyl) imide (C₁₆MImNTf2 ), and 1-methyl-3-n-octadecylimidazolium chloride (C₁₈MImCl), against the Acanthamoeba castellanii (ATCC30010) environmental strain and a clinical isolate (genotype T4).

RESULTS

Three IS showed being lethal to 100% of the Acanthamoeba trophozoites at the minimum inhibitory concentrations of 125 and 62.5 μg/mL (C₁₆MImMeS), 31.25 and 62.5 μg/mL (C₁₆MImCl), and 125 and 125 μg/mL (C₁₈MImCl) for ATCC30010 and isolate T4, respectively. C₁₆MImNTf2 did not demonstrate amoebicidal activity. All active IS caused the hemolysis of erythrocytes. The cytotoxic effect of the IS was tested in RAW macrophages and human brain microvascular endothelial cells, which demonstrated cytotoxicity in all concentrations tested against both cell lines. As a consequence, these IS with amoebicidal activity presented low selectivity index values (SI) (SI < 1.0), demonstrating lack of parasite selectivity.

CONCLUSION

Thus, C₁₆MImMeS, C₁₆MImCl, and C18MImCl seem to hold greater promise as components for contact lens cleaning and disinfection solutions, instead of direct human application.

Expression of Langerin/CD 207 and α-smooth muscle actin in ex vivo rabbit corneal keratitis model

The constant exposure of ocular surface to external environment and then to several microbial agents is often related to the pathogenesis of various inflammatory eye disorders. In the present study α-Smooth Muscle Actin (α-SMA) and Langerin CD/207 expression and function was investigated in a rabbit corneal keratitis. The inflammation was induced by the secreted form of glycoprotein B (gB1s) of HSV-1, in an ex vivo rabbit corneal model. α-SMA is often used as a marker for myofibroblasts. In this study, for the first time, we show α-SMA positive corneal epithelial cells, during HSV-1 cornea inflammation, demonstrating a crucial role in wound healing, especially during remodeling phase. Furthermore, we show the presence of Dendritic Cells Langerin CD/207 positive, located mainly in the basal epithelial layer and in corneal stroma during the inflammatory processes. Our result validating the ex vivo organotypic rabbit corneal model, for the study about pathogenesis of HSV-1 ocular infection.

[Clinical observation of ocular injury caused by chestnut burr]

Objective: To analyze the clinical characteristics and treatment of ocular injury caused by chestnut burr. Methods: Retrospective case series study. Data of 48 patients (48 eyes) with ocular injuries caused by chestnut burrs hospitalized in Qingdao Eye Hospital were collected from January 2013 to March 2019. All patients were followed up for at least 3 months. The time of seeking medical advice, lesion region, and characteristics and treatment methods were analyzed. Results: There were 48 patients, including 33 males and 15 females, aged 19 to 74 years [mean, (56±10) years]. The time of injury was late September (25 cases) and early October (23 cases). The shortest time to visit our hospital was 3 hours after injury, and the longest was 8 months after injury. There were 13 cases (27.1%, 13/48) with corneal and/or scleral foreign bodies. All patients were treated with corneal or scleral foreign body extraction. Twenty-four patients (50.0%, 24/48) developed fungal keratitis. Among them, 18 patients had a corneal ulcer, and the infection involved the superficial or full-thickness corneal layer. Six patients had no corneal ulcer, and the infection involved the deep stroma and corneal endothelial surface. The positive rate of fungal examination by confocal microscopy was 87.5% (21/24). Antifungal drugs (2 cases), corneal debridement (5 cases), conjunctival flap covering (2 cases), corneal stroma injection (1 case), and penetrating keratoplasty(14 cases) were given according to the depth of fungal infection. Most of the pathogens were Alternaria spp. Eleven patients (22.9%, 11/48) with necrotizing scleritis were treated with exploration of the sclera. Three patients had scleral foreign body residues on ultrasound biomicroscopy examination, which were removed by operation. Four patients were found to have fungi at the necrotic site of the sclera. Conclusions: The main types of ocular injuries caused by chestnut burrs are corneal and/or scleral foreign bodies, fungal keratitis, and necrotizing scleritis. Chestnut burr foreign bodies should be removed as soon as possible. In the case of fungal keratitis, a drug or surgical intervention should be carried out as early as possible. Necrotizing scleritis is often induced by long-term foreign body retention. Scleral incision and exploration is an effective form of treatment. (Chin J Ophthalmol, 2020, 56: 370-375).

Anterior Segment Optical Coherence Tomography in the Early Management of Microbial Keratitis: A Cross-Sectional Study

INTRODUCTION

Infectious keratitis is an important cause of visual loss. The purpose of this study was to investigate anterior segment optical coherence tomography patterns in infectious keratitis and evaluate the role of this tool in the early management of this disorder.

MATERIAL AND METHODS

In this cross-sectional study, we included patients with proven infectious keratitis, either by culture or therapeutic trial. Subjects underwent baseline anterior segment optical coherence tomography (Spectralis® anterior segment module, Heidelberg Engineering, Germany) performed by the same operator. We used anterior segment optical coherence tomography vertical and horizontal raster default scans with 6.0 mm scan lines.

RESULTS

Twenty-five patients (14 men and 11 women) were included. The most common risk factors identified were ocular trauma (11 cases) and contact lens wear (7 cases). Fifteen patients presented bacterial infection; three, fungal infection; two parasitic infection; and five cases presented a negative microbiological culture. Anterior segment optical coherence tomography depicted nine distinct morphological patterns.

DISCUSSION

Anterior segment optical coherence tomography allows the depth of corneal involvement to be assessed. When the only patterns identified were hyperreflective stromal lesion and stromal edema, the visual outcome was better. Cystic spaces were present in severe bacterial keratitis.

CONCLUSION

Anterior segment optical coherence tomography can complement biomicroscopy, allowing for a better characterization of corneal involvement at presentation that can help in staging and providing useful prognostic information.

Corneal epithelial injury-induced norepinephrine promotes Pseudomonas aeruginosa keratitis

Tissue injury causes the secretion of stress hormone catecholamine and increases susceptibility to opportunistic infection. Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen that is a leading cause of microbial keratitis usually associated with ocular injury or contact lens wear. However, the effect of catecholamine on P. aeruginosa induced corneal infection is unknown. Here, we test if norepinephrine (NE) would promote the progression of P. aeruginosa keratitis in mice. Adult C57BL/6 mouse corneas were scarified and then inoculated with P. aeruginosa. The content of NE was elevated in corneas after scarification and inoculation with P. aeruginosa. Then, exogenous NE was applied to the infected corneas at 24 h after inoculation; control eyes were treated with sterile saline. Topical application of NE aggravated the severity of P. aeruginosa keratitis, accompanied with the increase of clinical score, bacterial load, pathological changes, neutrophils infiltration, bacterial virulence factors and proinflammatory factors levels. In order to further verify the role of NE, N-(2-Chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride (DSP-4), a neurotoxin selected to deplete NE, was injected subconjunctivally 12 h before scarification. Pre-depletion of local NE by DSP-4 significantly alleviated the severity of corneal infection. Moreover, NE was also confirmed to increase the bacterial growth and the expression of virulence factors gene in vitro. Together, these data showed that increased corneal NE content facilitated the progression of P. aeruginosa keratitis in mice by amplifying host excessive inflammatory response and bacterial virulence. Therefore, targeting NE may provide a potential strategy for the treatment of P. aeruginosa keratitis.

Microbial keratitis in Sydney, Australia: risk factors, patient outcomes, and seasonal variation

PURPOSE

To provide recent data on patient demographics, clinical profile and outcomes of patients with microbial keratitis over a 5-year period at the Sydney Eye Hospital, and to identify seasonal variations of the main causative organisms.

METHOD

A retrospective study of patients with a clinical diagnosis of microbial keratitis and corneal scrape performed between 1 January 2012 and 31 December 2016. Clinical information was gathered from medical records and pathology data.

RESULTS

One thousand fifty-two eyes from 979 patients with a mean age of 54.7 ± 21.5 years (range 18-100 years) were included. The majority of cases were bacterial (65%) followed by polymicrobial (2.4%), fungi (2.3%), and culture-negative (31%). Common risk factors for microbial keratitis were contact lens wear (63%) and previous topical steroid use (24%). Factors significantly associated with poor patient outcomes in the multivariate model were age, visual acuity, and epithelial defect size (p < 0.05). Patients with fungal or polymicrobial keratitis presented with worse clinical features at initial and final presentation (p < 0.05). There was a significant variation in the occurrence of Pseudomonas aeruginosa (p = 0.018) and fungal keratitis (predominately made up of Candida and Fusarium species) (p = 0.056) in the hottest seasons.

CONCLUSION

Poorer outcomes are more likely to be seen in older patients and those presenting with poor visual acuity and large epithelial defects at the initial presentation.

Sustained-release voriconazole-thermogel for subconjunctival injection in horses: ocular toxicity and in-vivo studies

Background

Keratomycosis is a relatively common, sight threatening condition in horses, where treatment is often prolonged and costly. Subconjunctival (SCo) injections offer less resistance to drug diffusion than the topical route, resulting in better penetration to the ocular anterior segment. Voriconazole, a second generation triazole antifungal, is effective against common fungal organisms causing keratomycosis. If combined with a thermogel biomaterial, voriconazole can be easily injected in the SCo space to provide sustained drug release. The purpose of this study was to evaluate the drug concentrations in the anterior segment and clinical effects after SCo injections of voriconazole-containing thermogel: poly (DL-lactide-co-glycolide-b-ethylene glycol-b-DL-lactide-co-glycolide) (PLGA-PEG-PLGA) in healthy equine eyes.

Results

Voriconazole aqueous humor (AH) and tear concentrations were compared between 6 horses, receiving 1% voriconazole applied topically (0.2 mL, q4h) (Vori-Top) or 1.7% voriconazole-thermogel (0.3 mL) injected SCo (Vori-Gel). For the Vori-Gel group, voriconazole concentrations were measured in AH and tears at day 2 and then weekly for 23 days, and at day 2 only for the Vori-Top group. Ocular inflammation was assessed weekly (Vori-Gel) using the modified Hackett-McDonald scoring system. Ocular tissue concentrations of voriconazole following SCo 1.7% voriconazole-thermogel (0.3 mL) injections were evaluated post euthanasia in 6 additional horses at 3 different time points. Three horses received bilateral injections at 2 h (n = 3, right eye (OD)) and 48 h (n = 3, left eye (OS)) prior to euthanasia, and 3 horses were injected unilaterally (OS), 7 days prior to euthanasia. Voriconazole-thermogel was easily injected and well tolerated in all cases, with no major adverse effects. On day 2, drug concentrations in tears were higher in the Vori-Top, but not statistically different from Vori-Gel groups. For the Vori-Gel group, voriconazole was non-quantifiable in the AH at any time point. Total voriconazole concentrations in the cornea were above 0.5 μg/g (the target minimum inhibitory concentration (MIC) for Aspergillus sp.) for up to 48 h; however, concentrations were below this MIC at 7 days post treatment.

Conclusions

Voriconazole-thermogel was easily and safely administered to horses, and provided 48 h of sustained release of voriconazole into the cornea. This drug delivery system warrants further clinical evaluation.

[A clinical analysis of 1 414 cases of fungal keratitis]

Objective: To discuss clinical features and treatments of fungal keratitis, and to provide statistical data for clinical therapy and increase the therapeutic effects. Methods: This is a retrospective case series study. An analysis was performed by collecting patients' demography features, risk factors, onset time, lab results, clinical features and treatment from 1 414 cases of fungal keratitis from January 2006 to October 2016 in Qingdao Eye Hospital, Shandong Eye Institute. Results: In the 1 414 cases (1 414 patients), 1 174 patients (83.0%) came from different areas in Shandong Province, and the rest mainly from provinces on the north of Yangtze River. The age was 40 to 60 years in 874 cases (61.4%). The onset time was often in autumn and winter. The average duration between the onset and treatment was 1 to 74 days; 942 patients (67.1%) visited our hospital in 8-30 days after the appearance of the symptoms. Corneal trauma was the most common risk factor, especially injury by plants (367 cases, 26.4%). The positive rate of direct microscopic examination of potassium hydroxide wet mounts was 96.4%. The positive rate of confocal microscopy was 89.8%. Fungi were detected in corneal ulcer scrapings and (or) diseased corneal tissues obtained during surgery from 973 patients (68.8%). Most of the fungi were Fusarium (595 cases, 61.1%), followed by Alternaria (184 cases, 18.9%) and Aspergillus (119 cases, 12.2%). There were 603 cases (42.7%) of superficial and middle stromal infiltration, 614 cases (43.4%) of deep stromal infiltration and 197 cases (13.9%) of full-thickness corneal infiltration. Diameters of the corneal ulcer lesion were mostly between 4 and 6 mm (725 cases, 51.6%), followed by<3 mm (372 cases, 26.4%) and>6 mm (302 cases, 22.0%). Hypopyon was combined in 498 cases (35.2%), corneal perforation in 34 cases (2.4%), and endophthalmitis in 58 cases (4.1%). Surgery was performed in 1 198 cases (84.8%), including penetrating keratoplasty in 416 cases (29.4%), lamellar keratoplasty in 199 cases (14.1%), and corneal ulcer debridement in 532 cases (37.6%), with an effective rate of 98.1% (408 cases), 97.0% (193 cases) and 92.8% (494 cases), respectively. Two hundred and fifteen cases (15.2%) were treated with medical therapy alone, of which 147 cases (68.4%) were cured. Fifty-six patients (3.9%) finally lost their eye balls, including 54 cases of evisceration and 2 cases of ophthalmectomy. Conclusions: Fusarium is the main causative agent of fungal keratitis in Shandong Province. Direct microscopic examination of potassium hydroxide wet mounts is a simple, rapid and effective test method. Early diagnosis can be made if the result of corneal ulcer scraping examination is positive. Antifungal drug treatments can be done in early onset time. If the drug efficacy is poor or the patient's condition gets worse, immediate surgery is the key to controlling fungal keratitis. (Chin J Ophthalmol, 2020, 56:286-293).

[Ocular manifestations of measles in adults: About three cases]

Measles is a contagious viral infection that usually affects children. The disease is caused by morbillivirus, a virus of the family Paramyxoviridae. The clinical picture is characterized by four phases: incubation, invasion, eruption and desquamation. Ophthalmologic manifestations in measles are rare, dominated by conjunctivitis and keratitis. Corneal involvement is the main concern; it varies from simple superficial punctate keratitis to corneal perforation. We report three cases of acute keratitis in young adults during an epidemic. The epithelial involvement was peripheral, central or diffuse. The outcome was favorable under symptomatic topical treatment.

Biologically active pigment and ShlA cytolysin of Serratia marcescens induce autophagy in a human ocular surface cell line

BACKGROUND

The cellular process of autophagy is essential for maintaining the health of ocular tissue. Dysregulation of autophagy is associated with several ocular diseases including keratoconus and macular degeneration. It is known that autophagy can be used to respond to microbial infections and that certain microbes can exploit the autophagic process to their benefit. In this study, a genetic approach was used to identify surface-associated and secreted products generated by the opportunistic pathogen Serratia marcescens involved in activation of autophagy.

METHODS

A recombinant human corneal limbal epithelial cell line expressing a LC3-GFP fusion protein was challenged with normalized secretomes from wild-type and mutant S. marcescens derivatives. LC3-GFP fluorescence patterns were used to assess the ability of wild-type and mutant bacteria to influence autophagy. Purified prodigiosin was obtained from stationary phase bacteria and used to challenge ocular cells.

RESULTS

Mutations in the global regulators eepR and gumB genes highly reduced the ability of the bacteria to activate autophagy in corneal cells. This effect was further narrowed down to the secreted cytolysin ShlA and the biologically active pigment prodigiosin. Purified prodigiosin and ShlA from Escherichia coli further supported the role of these factors in activating autophagy in human corneal cells. Additional genetic data indicate a role for flagellin and type I pili, but not the nuclease, S-layer protein, or serratamolide biosurfactant in activation of autophagy.

CONCLUSIONS

This work identifies specific bacterial components that activate autophagy and give insight into potential host-pathogen interactions or compounds that can be used to therapeutically manipulate autophagy.

Contribution of anti-inflammatory and anti-virulence effects of azithromycin in the treatment of experimental Staphylococcus aureus keratitis

Background

We aimed to demonstrate the contribution of anti-inflammatory and anti-virulence effects of azithromycin (AZM) in ocular surface infection treatment.

Methods

Staphylococcus aureus was injected into the corneal stroma of rabbits to induce keratitis. AZM at concentrations of 0.01, 0.1, and 1% was instilled into the eye twice daily. The eyes were examined using a slit lamp and scored. The viable bacteria in the cornea were counted at 48 h post infection. To evaluate the anti-inflammatory efficacy of AZM, S. aureus culture supernatant-induced anterior ocular inflammation in rabbit was examined using a slit lamp and scored. To evaluate the inhibitory effect of AZM on bacterial toxin production, S. aureus was cultured with AZM and hemolytic reaction in the culture supernatant was determined.

Results

In the bacterial keratitis model, AZM dose-dependently inhibited the increase in the clinical score. The viable bacterial count in the cornea treated with 1% AZM significantly decreased compared with that of the vehicle, whereas bacterial count in 0.01 and 0.1% AZM-treated corneas was similar to that of the vehicle. In the anterior ocular inflammation model, 0.1 and 1% AZM inhibited the increase in the clinical score. AZM inhibited hemolytic reaction at concentrations that did not inhibit bacterial growth.

Conclusions

The results demonstrated that AZM has not only anti-bacterial, but also anti-inflammatory effects, and inhibits bacterial toxin production leading to ocular surface damage in bacterial infection. Thus, the therapeutic effect of AZM against ocular infections is expected to be higher than that which could be assumed if it only had anti-bacterial activity.

Lipofilling of the upper eyelid to treat paralytic lagophthalmos

Lagophthalmos is one of the most unpleasant and dangerous conditions that affect patients with facial palsy. The lack of ocular protection leads to corneal problems (such as conjunctival infections, acute and chronic keratitis, corneal ulcerations, and blindness). A dynamic reanimation of blinking eyelids is the therapeutic gold standard. However, success is not guaranteed with these dynamic techniques; even if results are good, blinking is usually restored within a year of the initial operation. Procedures that act more rapidly and have a higher success rate are needed. We proposed that lipofilling of the upper eyelid would improve eye closure, exploit the advantages of using autologous fat, and avoid the risks of exposure or migration associated with loading the lid with gold. Between 2012 and September 2018, we did upper eyelid lipofilling procedures for 75 patients with unilateral facial palsy. The main favourable result of lipofilling of the upper lid was the immediate improvement in corneal discomfort. Everybody described a partial to total increase in corneal comfort postoperatively. In the treatment of paralytic lagophthalmos, lipofilling of the upper eyelid produces favourable aesthetic and functional results, ocular health is restored, and the patients' quality of life is improved.

Molecular identification of Fusarium species complex isolated from clinical samples and its antifungal susceptibility patterns

Background and Purpose:

More than 300 Fusarium species are grouped into approximately 23 species complexes out of which around 70 are involved in human infections. The nomenclature of these species has undergone considerable changes in recent years. These species cause localized infections in individuals while inducing systemic infections mainly in immunocompromised patients. The present study was conducted to identify Fusarium species in clinical isolates by molecular methods and determine their in vitro minimum inhibitory concentration (MIC) patterns to address the lack of data in this domain in Northern India.

Materials and Methods:

For the purpose of the study, Fusarium isolates obtained from various clinical samples were sent to the Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands, for molecular identification. The MIC testing was performed using the microbroth dilution method as per the Clinical and Laboratory Standards Institute reference method (M38-A2).

Results:

Fusarium was isolated from 33 patients (i.e., 1, 1, 2, 14, and 15 cases with endophthalmitis, sinusitis, pulmonary involvement, onychomycosis, and keratitis, respectively). These 33 isolates belonged to three species complexes, namely F. solani species complex (FSSC; n=13), F. fujikuroi species complex (FFSC; n=13), and F. incarnatumequiseti species complex (FIESC; n=7). The species identified within FSSC, FFSC, and FIESC included F. keratoplasticum (n=6)/F. falciforme (n=6)/F. solani (n=1), F. proliferatum (n=7)/F. sacchari (n=5)/F. anthophilum (n=1), and F. incarnatum SC species (n=6)/F. equiseti SC species (n=1), respectively. The MIC results showed that all isolates had a lower MIC against amphotericin B than against the other antifungal agents.

Evaluation of molecular identification of Aspergillus species causing fungal keratitis

Fungal keratitis caused by the species of Aspergillus is a common and leading problem in developing countries like India. In this study, a total of 135 isolates from Aspergillus keratitis were studied by sequence analyses of the internal transcribed spacer (ITS) region performed by nucleotide-nucleotide BLAST analysis followed by the initial identification of the isolates based on conidial and colony morphology. The sequence analysis revealed several unusual species which were never reported in eye infections such as A. tamrii, A. tubingensis, A. braslliensis, A. nomius, A. pseudonomius, A. sydowii, Eurotium amstelodami. The sequence analysis of the ITS region; the β-tubulin and calmodulin genes brought out the genetic diversity among the isolates as the study intended to locate a more sensitive target sequence to study genetic diversity among a set of test fungal isolates. The PCR amplified sequences of the test isolates of the study as well as sequences belonging to section Flavi obtained from Genbank database were compared and analyzed along with three standard isolates by phylogenetic tree (Neighbor-joining) as to find out a target region/gene that could produce a better resolution to differentiate the isolates. Accordingly, the calmodulin gene had provided better resolution compared to ITS and β-tubulin to study the diversity among the test Aspergillus species isolated from fungal corneal ulcer.

Microsporidial stromal keratitis in a cat

A 12 year-old female spayed felid presented after a 35 day history of right eye pain. On examination, a sub-epithelial opacity was identified in the cornea. A lamellar keratectomy was performed and histopathological analysis revealed low numbers of 2x4um, Gram, Hamatoxylin-eosin and Gomori methanamine-silver positive spores. Transmission electron microscopy found ultrastructural findings consistent with the phylum Microspora. To the author's knowledge, this is only the second case of microsporidial stromal keratitis reported in a felid.

Nerolidol inhibits the LOX-1 / IL-1β signaling to protect against the Aspergillus fumigatus keratitis inflammation damage to the cornea

PURPOSE

Nerolidol, a naturally occurring sesquiterpene has both anti-microbial and anti-inflammatory properties. The current study aims to investigate the antifungal and the anti-inflammatory effects of nerolidol against mouse Aspergillus fumigatus (A. fumigatus) keratitis.

METHODS

The minimum inhibitory concentration (MIC) and cytotoxicity tests were used to study the antifungal ability. For in vivo and in vitro studies, the mouse corneas and the human corneal epithelial cells (HCECs) infected with A. fumigatus spores were intervented with nerolidol or phosphate buffer saline (PBS). Thereafter, the effect of the nerolidol on the response against inflammation was analyzed using the following parameters: recruitment of the neutrophils or macrophages and the expression of the lectin-type oxidized low density lipoprotein receptor-1 (LOX-1) and interleukin 1β (IL-1β). Techniques used were the slit lamp, immunofluorescence, myeloperoxidase (MPO) detection, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot.

RESULTS

Nerolidol directly inhibits the growth of A. fumigatus. The administration of nerolidol reduced the severity of fungal keratitis with infiltration of fewer inflammatory cells and reduced levels of the LOX-1, as well the anti-inflammatory cytokines such as IL-1β were reduced compared with the PBS group. Additionally, in vitro studies showed that treatment with nerolidol inhibited the production of the LOX-1 / IL-1β levels in A. fumigatus stimulated HCECs.

CONCLUSION

Nerolidol attenuated the A. fumigatus keratitis inflammatory response by inhibiting the growth of A. fumigatus, reducing the recruitment of the neutrophils and the macrophages, and inhibiting the LOX-1/ IL-1β signaling.

Fungal keratitis caused by a rare pathogen, Colletotrichum gloeosporioides, in an east coast city of China

BACKGROUND

To report a case of fungal keratitis caused by Colletotrichum gloeosporioides in an east coast city of China, which are rare pathogens that cause fungal keratitis in humans.

METHODS

A 52-year-old man whose right eye was injured by a branch of an apple tree during farm work was referred to our Hospital. He was examined by Slit-lamp and the HRT II-RCM confocal scanning microscope, thus suggesting filamentous. Orneal scrapings were acquired and then inoculated into Sabouraud medium incubated at 28°C and 37°C. In vitro antifungal susceptibility tests were performed following the CLSI M38-A2 for Filamentous Fungi. Surgical intervention was advised because the abscess in the anterior chamber of the right eye was not completely absorbed.

RESULTS

The Colletotrichum gloeosporioides isolate was identified by MALDI-TOF mass spectrometry and the BLAST after DNA sequencing of the amplified internal transcribed spacer (ITS) in rRNA. The patient's eye condition is under control and the patient's vision remains at the level of light perception (LP).

CONCLUSIONS

We report the rare keratitis caused by C. gloeosporioides in eastern China, which has not been published. Suddenly ocular trauma and old surgical intervention may be the risk factors associated with Colletotrichum keratitis.

Pigmented Corneal Ulcer

Purpose

To report the clinical characteristics, laboratory findings, and treatment of a rare case of keratitis caused by pigmented fungi Bipolaris hawaiiensis.

Case Report

A 55-year-old man presented with a history of trauma with vegetative matter in his left eye. Slit lamp biomicroscopic examination revealed the presence of a brownish-black pigmented plaque with surrounding infiltrates. Corneal scrapings revealed multiple septate hyphae. Culture revealed growth of the Bipolaris species. The patient was treated with topical natamycin 5%, topical voriconazole 1%, and oral itraconazole followed by intracameral amphotericin B (5 μg/mL). The patient responded well to the treatment.

Conclusion

Brown pigmented infiltrates are an important clinical feature of dematiaceous fungi. B. hawaiiensis is a rare cause of corneal phaeohyphomycosis. Our patient responded well to intracameral amphotericin B, which obviated the need for penetrating keratoplasty.

Rose bengal photodynamic antimicrobial therapy to inhibit Pseudomonas aeruginosa keratitis isolates

To evaluate the in vitro efficacy of rose bengal and riboflavin photodynamic antimicrobial therapy for inhibition the growth of four Pseudomonas aeruginosa (P. aeruginosa) isolates. Four different clinical P. aeruginosa isolates were collected from patients with confirmed keratitis. Each strain was mixed with either sterile water, 0.1% riboflavin solution, or 0.1% rose bengal solution to yield a final bacteria concentration of 1.5 × 10⁷ CFU/mL. Aliquots from each suspension were plated onto nutrient agar in triplicate. Plates were separated into two groups: (1) no irradiation and (2) 5.4 J/cm² of radiant exposure with custom-made LED irradiation sources. Separate irradiation sources were used for each photosensitizer. The riboflavin groups used a UV-A light source (375 nm) and rose bengal groups used a green light source (525 nm). Plates were photographed at 72 h and custom software measured bacterial growth inhibition. Growth inhibition to riboflavin and rose bengal PDAT showed strain-dependent variability. All four strains of P. aeruginosa showed greatest growth inhibition (89-99%) in the green irradiated-rose bengal group. The UV-A-irradiated riboflavin showed inhibition of 24-44%. UV-A irradiation only showed minimal inhibition (7-14%). There was little inhibitory effect in the non-irradiated photosensitizer groups. Rose bengal PDAT had the greatest inhibitory effect on all four P. aeruginosa isolates. In the UV-A-irradiated riboflavin group, there was moderate inhibition within the irradiation zone; however, there was no inhibition in the non-irradiated groups. These results suggest that rose bengal PDAT may be an effective alternative treatment for Pseudomonas aeruginosa infections.

Human Pythiosis: Emergence of Fungal-Like Organism

Pythiosis is an emerging infectious disease caused by the aquatic oomycete Pythium insidiosum, a fungal-like organism. It is believed that P. insidiosum's zoospores, its infected form, play major role in pathogenesis. Vascular and ocular infections are the most common clinical manifestation in humans. It is difficult to establish the diagnosis given its relatively rarity and difficulty to distinguish P. insidiosum from other molds. Delay in diagnosis and treatment has been associated with poor outcomes. High index of suspicion is the key, particularly in thalassemia patients with arterial insufficiency and patients with fungal keratitis/endophthalmitis without improvement on antifungal therapy. Tissue culture and zoospore induction remain gold standard for diagnosis; however, DNA-based method should be performed simultaneously. The combination of radical surgery, antifungal agents, and immunotherapy has been recommended. It was previously believed that surgery with negative surgical margins was the essential to survive in vascular pythiosis; however, it was recently found that patients could have residual disease despite documented negative surgical margins as infected clot may be dislodged to proximal arterial sites prior to surgery. Serum β-D-glucan (BG) has been used to monitor disease response after treatment initiation in vascular pythiosis. A significant decrease in BG levels within 2 weeks after surgery is indicative of the absence of residual infection. Unfortunately, monitoring tools for ocular pythiosis are not yet available. Itraconazole plus terbinafine have generally been used in P. insidiosum-infected patients; however, antibacterial agents, including azithromycin and linezolid, have also been used with favorable outcomes in ocular disease. Recently, azithromycin or clarithromycin plus doxycyclin were used in two relapsed vascular pythiosis patients with good outcomes.

Pigmentary keratitis in pugs in the United Kingdom: prevalence and associated features

Background

Pigmentary keratitis (PK) is commonly recognised in Pugs, but its aetiology is not completely understood. The aim of this study was to determine the prevalence and associated features of PK in Pugs in the United Kingdom (UK).

Results

A total of 210 Pugs (420 eyes) were recruited from 12 UK dog shows and social events. The median age of Pugs recruited was 2.50 years (range 0.25–16.25 years). Pigmentary keratitis was detected in 369/420 (87.8%) eyes and in at least one eye 193/210 (91.9%) Pugs, of which 17/193 (8.8%) were affected unilaterally and 176/193 (91.2%) bilaterally. Pigmentary keratitis was typically mild to moderate (46.3 and 49.9% of eyes, respectively). Detection of PK was significantly associated with increased age (P = 0.002) and the presence of medial entropion of the lower eyelid (MELE) (P = 0.001). Severity of PK was significantly associated with the grade of MELE (P < 0.001). There was also a correlation between the presence of limbal pigment and PK (P = 0.036) that warrants further study.

Conclusions

This study estimated a high disease prevalence of PK in UK Pugs, and demonstrated significant associations with age and the presence of MELE. These associations, which have not been previously reported, offer an insight into the underlying pathophysiology of this condition in Pugs. The results encourage further population research, such as prospective longitudinal studies. These findings also support the development of clinical and breeding strategies based on the reduction of MELE and, possibly, limbal pigment.

Vibrio cholerae non-O1 - the first reported case of keratitis in a healthy patient

Background

Vibrio cholerae non-O1 is a virulent pathogen that causes significant morbidity and mortality in humans. Herein, we report a case of corneal ulcer caused by this pathogen.

Case presentation

A 59-year-old fisherman with no systemic history was struck in the right eye by a marine shrimp and developed keratitis. Corneal scrapping culture revealed the presence of the V. cholerae non-O1, and its identification was confirmed by Analytical Profile Index 20E system and polymerase chain reaction. He was successfully treated with topical levofloxacin (0.3%) and fortified amikacin (12.5 mg/mL) for 2 weeks. The visual acuity recovered to 20/25 after treatment without complications.

Conclusions

This is the first case report of keratitis caused by V. cholerae non-O1 strain. Ocular injury by marine creatures and contaminated seawater can contribute to severe corneal ulcer. Early diagnosis can be achieved by meticulous history taking and a comprehensive laboratory workup. Simultaneously, an effective antibiotic therapy can lead to a positive outcome.

Challenges in the diagnosis of microbial keratitis: A detailed review with update and general guidelines

The incidence of microbial keratitis (MK) is variable worldwide with an estimated 1.5–2 million cases of corneal ulcers in developing countries. The complications of MK can be severe and vision threatening. Therefore, proper diagnosis of the causative organism is essential for early successful treatment. Accurate sampling of microbiological specimens in MK is an important step in identifying the infective organism. Corneal scrapping, tear samples and corneal biopsy are examples of specimens obtained for the investigative procedures in MK. Ophthalmologists especially in an emergency room setting should be aware of the proper sampling techniques based on their microbiology-related basic information for each category of MK. This review article briefly describes the clinical presentation and defines in details the best updated diagnostic methods used in different types of MK. It can be used as a guide for ophthalmology trainees and general ophthalmologists who may be handling such cases at initial presentation.

[Graft virus infection following corneal transplantation]

Graft rejection and endothelial cell loss were believed to be the main reasons for graft edema following keratoplasty. With the application of various molecular biological detection methods in ophthalmology, virus infection has emerged and become an important contributing factor for graft failure. This review focused on the etiology, clinical manifestation and diagnosis methods for virus infection following keratoplasty, and discussed possible prevention and treatment.(Chin J Ophthalmol, 2019, 55: 713-716).

Acute surgical vs non-surgical management for ocular and peri-ocular burns: a systematic review and meta-analysis

Background

Burn-related injury to the face involving the structures of the eyes, eyelids, eyelashes, and/or eyebrows could result in multiple reconstructive procedures to improve functional and cosmetic outcomes, and correct complications following poor acute phase management. The objective of this article was to evaluate if non-surgical or surgical interventions are best for acute management of ocular and/or peri-ocular burns.

Methods

This systematic review and meta-analysis compared 272 surgical to 535 non-surgical interventions within 1 month of patients suffering burn-related injuries to 465 eyes, 253 eyelids, 90 eyelashes, and 0 eyebrows and evaluated associated outcomes and complications. The PubMed, Embase, Cochrane Library, Web of Science, and Scopus databases were systematically and independently searched. Patient and clinical characteristics, surgical and medical interventions, outcomes, and complications were recorded.

Results

Eight of the 14,927 studies queried for this study were eligible for the systematic review and meta-analysis, with results from 33 of the possible 58 outcomes and complications using Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) and Cochrane guidelines. Surgery was associated with standard mean differences (SMD) 0.44 greater visual acuity on follow-up, SMD 1.63 mm shorter epithelial defect diameters on follow-up, SMD 1.55 mm greater changes in epithelial diameters from baseline, SMD 1.17 mm² smaller epithelial defect areas on follow-up, SMD 1.37 mm² greater changes in epithelial defect areas from baseline, risk ratios (RR) 1.22 greater numbers of healed epithelial defects, RR 11.17 more keratitis infections, and a 2.2 greater reduction in limbal ischemia compared to no surgical intervention.

Conclusions

This systematic review and meta-analysis found that compared to non-surgical interventions, acute surgical interventions for ocular, eyelid, and/or eyelash burns were found to have greater visual acuity on follow-up, shorter epithelial defect diameters on follow-up, greater changes in epithelial diameters from baseline, smaller epithelial defect areas on follow-up, greater changes in epithelial defect areas from baseline, greater numbers of healed epithelial defects, more keratitis infections, and a greater reduction in limbal ischemia, possibility preventing the need of a future limbal stem cell transplantation.