Ocular Fungal Infections Research Articles

Fluconazole-Niosome-Laden Contact Lens: A Promising Therapeutic Approach for Prolonged Ocular Delivery and Enhanced Antifungal Activity

BackgroundTraditional routes of administration of fluconazole such as eye drops have a low therapeutic efficacy due to insufficient bioavailability.PurposeHerein, a fluconazole noisome-laden contact lens was prepared to control and prolong the drug release and improve its bioavailability.MethodsTwo methods have been used to prepare fluconazole niosomes: solvent injection method and thin film hydration method utilizing span 60 and cholesterol mixture. Subsequently, formulations were optimized using three factors and a two-level factorial design and were subjected to in-vitro characterization for the size of niosomes, zeta potential, entrapment efficiency percent, and cytotoxicity study. The optimized fluconazole niosomes were further entrapped in contact lenses by the soaking method and were evaluated according to in-vitro release profile, and antimicrobial activity.ResultsThe results revealed that the investigated fluconazole niosomes are of nano-size ranging from 228.2 to 769.2 nm with zeta-potential values between − 18.1 and − 60.2 mV. The entrapment efficiency percentage ranged from 51.3 to 75%. Fluconazole was released from fluconazole noisome-laden contact lens and showed a prolonged release up to 48–72 h with a cumulative release of 79.62%. Statistical analysis showed that fluconazole-noisome-laden contact lenses have a significant impressive fungal adhesion reduction as compared to fluconazole-laden contact lenses.ConclusionFluconazole noisome-laden contact lenses are a promising therapeutic way for effective and prolonged treatment of ocular fungal infection.

Nanoemulsion Carriers for Ocular Fungal Infection: Main Emphasis on Keratomycosis.

Keratomycosis, also termed fungal keratitis (FK), is an invasive eye condition for which there is a lack of available effective treatment due to pharmacological shortages and vital ocular obstacles. This severe corneal infection typically suppurates and eventually ulcerates, ultimately causing blindness or decreased vision. According to epidemiological studies, FK is more common in warm, humid places with an agricultural economy. The use of nanoemulsion carriers for ocular fungal infection has been promoting better treatment and patient compliance. The persistent fungal infection like FK, affecting particularly the stroma heralds complications thereby posing difficulty in diagnosis and treatment. To help treat refractory cases and improve outcomes, recently targeted drug delivery techniques and novel antifungal drugs shall be explored. A delay in diagnosis may cause corneal fungal infections to have irreversible consequences, which cannot be avoided. However, infections can develop into ocular perforation even after receiving intense care. The commonly used chemotherapy for FK is based on topical (natamycin 5% is typically first-line therapy) and systemic administration of azole drugs. To address the problems related to better treatment, various nanoemulsion carriers were discussed. Novel drug delivery systems based on nanoemulsions are a viable therapeutic option for treating keratomycosis and may be a candidate method for overcoming obstacles in the treatment of many other ocular illnesses when combined with different hydrophobic medicines. With a brief explanation of the pathogenesis, this article seeks to give readers a thorough analysis of current trends, various treatment choices, and care strategies for fungal keratitis.

Advances in Liposomes-Based-Therapeutics as Cutting-Edge for Ocular Fungal Infections: An Updated Review

Advances in Liposomes-Based-Therapeutics as Cutting-Edge for Ocular Fungal Infections: An Updated Review

Microemulsion as Novel Drug Delivery for Fungal Eye Infection

The cornea, orbit, and other ocular tissues may get infected by fungi. Ophthalmic mycoses, often known as ocular fungal infections, are a significant cause of morbidity and blindness. For fungus infections, a brand-new azole derivative has been authorized. New immunological techniques would also be beneficial in the future for enhancing patient outcomes. Treatment of ocular illnesses presents a significant barrier in terms of getting medications into the eyes using traditional drug delivery methods, such as solutions. The main barriers are those between blood and the eyes, between lachrymal fluid and the eyes, and between medication losses from the ocular surface brought on by lachrymal fluid secretion. To increase the bioavailability and lengthen the residence duration of medications administered topically to the eye, a variety of ocular drug delivery carriers have been developed. The microemulsion is created using the PHASE TITRATION METHOD. Due to the dual hydrophilic and lipophilic properties of microemulsions, the loaded medications can diffuse passively and become significantly partitioned in the varying lipophilic-hydrophilic ocular barrier. This abstract will provide details on the microemulsions used to treat fungal infections of the eyes.

Sertaconazole-PLGA nanoparticles for management of ocular keratitis

Ocular fungal infections can pose severe health conditions that may develop into vision impairment and blindness. Sertaconazole (STZ) is a widely used antifungal; however, its low aqueous solubility restricts its topical application for managing ocular keratitis. This investigation aimed to develop polymeric nanoparticles as delivery carriers to improve the ophthalmic availability of STZ for treating fungal keratitis. The impact of STZ solid dispersion incorporation within polymeric nanoparticles for in vitro drug release enhancement was also evaluated. STZ-laden PLGA NPs were formulated via nanoprecipitation technology, using a 24-full factorial layout to optimize the formulation. The formed nanoparticles were assessed for encapsulation efficiency percentage, hydrodynamic size, surface charge, and polydispersity index. The selected formula exhibited a particle size of 305.9 ± 4.36 nm, an entrapment efficiency (EE%) of 98.8 ± 0.008%, a surface charge of 22.57 ± 0.23 mV, and a low polydispersity index, indicating a uniform size distribution. Incorporating STZ in a solid dispersion form with PEG 2000 at a 1:3 w/w drug-to-carrier ratio increased the hydrodynamic size of the PLGA NPs. However, no significant variation in the entrapment efficiency percentage was recorded. The developed STZ-solid dispersion-loaded PLGA NPs have round-shaped structures. DSC and FTIR spectroscopy data indicated drug amorphization with successful loading within the PLGA matrix. Introducing the drug as a solid dispersion within PLGA NPs resulted in enhancing the rate of drug dissolution at initial time intervals, followed by a controlled drug release over 24 h. STZ-PEG2000-laden PLGA NPs enhanced permeability through rabbits’ corneas (Papp), 2.5-fold higher versus STZ-loaded PLGA NPs. The antimycotic activity of the developed formulation was tested against Candida albicans, and a 4-fold reduction in the MIC value was detected upon applying the nanoparticles’ formulation embedding STZ solid dispersion versus that containing the free drug. In conclusion, the formulation of solid dispersions of STZ loaded in PLGA nanoparticles may serve as a starting point for an efficient approach to the ocular delivery of hydrophobic medications and a viable setup for the upcoming research in animal models of fungal keratitis.

Grzybicze zapalenie błony naczyniowej – współczesna diagnostyka i leczenie

Ocular fungal infections annually affect more than one million individuals worldwide. They may occur as endogenous or exogenous fungal uveitis/ endophthalmitis. The latter appear after intraocular procedures, perforating ocular trauma or secondary to fungal keratitis. Although culturing is still the standard in the diagnosis of fungal endopthalmitis, more sensitive and specific and faster diagnostics tests include molecular tests; polymerase chain reaction and next generation sequencing. Also highly sensitive is the serum assessment of galactomannan and beta-D-glucan – two markers of fungal cell wall components. Treatment of fungal uveitis is difficult, mainly due to the limited permeability of antifungal drugs into intraocular fluids. In the treatment of fungal uveitis, systemic antifungal drugs are used, which in the case of vitreous involvement are combined with amphotericin B or voriconazole intravitreal injections. In cases with severe endophthalmitis and intravitreal abscess the vitrectomy is a treatment of choice.

Candida Biofilm Eye Infection: Main Aspects and Advance in Novel Agents as Potential Source of Treatment.

Fungi represent a very important cause of microbial eye infections, especially in tropical and developing countries, as they could cause sight-threating disease, such as keratitis and ocular candidiasis, resulting in irreversible vision loss. Candida species are among the most frequent microorganisms associated with fungal infection. Although Candida albicans is still the most frequently detected organism among Candida subspecies, an important increase in non-albicans species has been reported. Mycotic infections often represent an important diagnostic-clinical problem due to the difficulties in performing the diagnosis and a therapeutic problem due to the limited availability of commercial drugs and the difficult penetration of antifungals into ocular tissues. The ability to form biofilms is another feature that makes Candida a dangerous pathogen. In this review, a summary of the state-of-the-art panorama about candida ocular pathology, diagnosis, and treatment has been conducted. Moreover, we also focused on new prospective natural compounds, including nanoparticles, micelles, and nanocarriers, as promising drug delivery systems to better cure ocular fungal and biofilm-related infections. The effect of the drug combination has also been examined from the perspective of increasing efficacy and improving the course of infections caused by Candida which are difficult to fight.

Natamycin Ocular Delivery: Challenges and Advancements in Ocular Therapeutics.

Fungal keratitis, an ocular fungal infection, is one of the leading causes of monocular blindness. Natamycin has long been considered the mainstay drug used for treating fungal keratitis and is the only US Food and Drug Administration (USFDA)-approved drug, commercially available as a topical 5% w/v suspension. Furthermore, ocular fungal infection treatment takes a few weeks to months to recover, and the available marketed antifungal suspensions are associated with poor residence time, limited bioavailability (< 5%) and high dosing frequency as well as minor irritation and discomfort. Despite these challenges, natamycin is still the preferred drug choice for treating fungal keratitis, as it has fewer side effects and less ocular toxicity and is more effective against Fusarium species than other antifungal agents. Several novel therapeutic approaches for the topical delivery of natamycin have been reported to overcome the challenges posed by the conventional dosage forms and to improve ocular bioavailability for the efficient management of fungal keratitis. Current progress in the delivery systems uses approaches aimed at improving the corneal residence time, bioavailability and antifungal potency, thereby reducing the dose and dosing frequency of natamycin. In this review, we discuss the various strategies explored to overcome the challenges present in ocular drug delivery of natamycin and improve its bioavailability for ocular therapeutics.

Eye fungal infections: a mini review.

Ocular fungal infections annually affect more than one million individuals worldwide. The management of these infections is problematic, mainly due to the limited availability of effective antifungal agents. Thus, ocular infections are increasingly recognized as important causes of morbidity and blindness, especially keratitis and endophthalmitis. Thus, this review aims to demonstrate the importance of fungal eye infections through the description of the main related aspects, with emphasis on the treatment of these infections. For this purpose, a search for scientific articles was conducted in databases, such as Medline, published from 2000 onwards, addressing important aspects involving fungal eye infections. In addition, this work highlighted the limited therapeutic arsenal available and the severity associated with these infections. Thus, highlighting the importance of constantly updating knowledge about these pathologies, as it contributes to agility in choosing the available and most appropriate therapeutic alternatives, aiming at positive and minimally harmful results for that particular patient.

RETRACTED: Development of thermosensitive hydrogel of Amphotericin-B and Lactoferrin combination-loaded PLGA-PEG-PEI nanoparticles for potential eradication of ocular fungal infections: In-vitro, ex-vivo and in-vivo studies

The most prevalent conditions among ocular surgery and COVID−19 patients are fungal eye infections, which may cause inflammation and dry eye, and may cause ocular morbidity. Amphotericin-B eye drops are commonly used in the treatment of ocular fungal infections. Lactoferrin is an iron-binding glycoprotein with broad-spectrum antimicrobial activity and is used for the treatment of dry eye, conjunctivitis, and ocular inflammation. However, poor aqueous stability and excessive nasolacrimal duct draining impede these agens' efficiency. The aim of this study was to examine the effect of Amphotericin-B, as an antifungal against Candida albicans, Fusarium, and Aspergillus flavus, and Lactoferrin, as an anti-inflammatory and anti-dry eye, when co-loaded in triblock polymers PLGA-PEG-PEI nanoparticles embedded in P188-P407 ophthalmic thermosensitive gel. The nanoparticles were prepared by a double emulsion solvent evaporation method. The optimized formula showed particle size (177.0 ± 0.3 nm), poly-dispersity index (0.011 ± 0.01), zeta-potential (31.9 ± 0.3 mV), and entrapment% (90.9 ± 0.5) with improved ex-vivo pharmacokinetic parameters and ex-vivo trans-corneal penetrability, compared with drug solution. Confocal laser scanning revealed valuable penetration of fluoro-labeled nanoparticles. Irritation tests (Draize Test), Atomic force microscopy, cell culture and animal tests including histopathological analysis revealed superiority of the nanoparticles in reducing signs of inflammation and eradication of fungal infection in rabbits, without causing any damage to rabbit eyeballs. The nanoparticles exhibited favorable pharmacodynamic features with sustained release profile, and is neither cytotoxic nor irritating in-vitro or in-vivo. The developed formulation might provide a new and safe nanotechnology for treating eye problems, like inflammation and fungal infections.

Trends of ocular fungal infections in North China (2001–2020)

ObjectivesTo analyze the epidemiologic features, culture positivity, the fungal spectrum of different sites of ocular infection in North China over 20 years from 2001 to 2020. Methods11, 635 patients suspected of ocular fungal infection were reviewed. The demographic profile, fungal positive culture rate among different sites, the distribution, and trends of main pathogens among cornea and intraocular fluid were analyzed. ResultsAmong 11, 635 samples, the positive culture rate of ocular fungal infection was 23.6%. Most of samples (83.1%) were from cornea, and their culture positivity was 26.9%. Fungal keratitis occurred more often during the harvesting season (October to December; 34.0%) than in other seasons (average: 22.0%). Fusarium sp. (53.2%), Aspergillus sp. (15.9%) and Alternaria sp. (12.5%) were the most common fungal species of ocular mycotic infections in the past two decades in north China. 2562 organisms were identified from cornea, of which 1443 (56.3%) were Fusarium sp., 403 (15.7%) and 329 (12.8%) were Aspergillus sp., and Alternaria sp., respectively. Of the 120 fungi isolated from the intraocular fluid, the most common was Aspergillus sp. (33.3%), followed by Fusarium sp. (24.2%) and Candida sp. (15.0%). ConclusionsFusarium sp., Aspergillus sp. and Alternaria sp. were the most common organisms in cases of fungal keratitis, while Aspergillus sp., Fusarium sp. and Candida sp. were the most frequent isolates for fungal endophthalmitis.

Development of a Luliconazole Nanoemulsion as a Prospective Ophthalmic Delivery System for the Treatment of Fungal Keratitis: In Vitro and In Vivo Evaluation.

Luliconazole (LCZ), a novel imidazole drug, has broad-spectrum and potential antifungal effects, which makes it a possible cure for fungal keratitis; nevertheless, its medical use in ocular infections is hindered by its poor solubility. The purpose of this study was to design and optimize LCZ nanoemulsion (LCZ-NE) formulations using the central composite design-response surface methodology, and to investigate its potential in improving bioavailability following ocular topical administration. The LCZ-NE formulation was composed of Capryol 90, ethoxylated hydrogenated castor oil, Transcutol® P and water. The shape of LCZ-NE was spherical and uniform, with a droplet size of 18.43 ± 0.05 nm and a low polydispersity index (0.070 ± 0.008). The results of an in vitro release of LCZ study demonstrated that the LCZ-NE released more drug than an LCZ suspension (LCZ-Susp). Increases in the inhibition zone indicated that the in vitro antifungal activity of the LCZ-NE was significantly improved. An ocular irritation evaluation in rabbits showed that the LCZ-NE had a good tolerance in rabbit eyes. Ocular pharmacokinetics analysis revealed improved bioavailability in whole eye tissues that were treated with LCZ-NE, compared with those treated with LCZ-Susp. In conclusion, the optimized LCZ-NE formulation exhibited excellent physicochemical properties, good tolerance, enhanced antifungal activity and bioavailability in eyes. This formulation would be safe, and shows promise in effectively treating ocular fungal infections.

Ni/Ni(OH)2-rGO nanocomposites sensor for the detection of long forgotten mycotoxin, xanthomegnin

Xanthomegnin, a known fungal toxin, secondary metabolite, and pigment diffuses from the dermatophytes has gained attention as local virulence factor because of the mutagenicity, toxicity, cytocidal, and immunosuppressive properties. Not only as a dermatophyte in skin related disorders, the production of xanthomegnin is implicated as a powerful diagnostic marker in patients suffering from ocular mycoses. Incidentally also attributed to death in livestock's majorly by exposing themselves to food-borne fungi like Aspergillus and Penicillium. The production of xanthomegnin in dermetophytic species Trichophyton rubrum, found commonly in infected skin and nails. In this study nickel/nickel hydroxide nanoparticles decorated reduced graphene oxide (Ni/Ni(OH)2-rGO) modified glassy carbon electrode has been successfully used for non-enzymatic detection of xanthomegnin. The Ni/Ni(OH)2-rGO composites were synthesized through a simple microwave assisted technique with less harmful reducing agent. The UV-visible spectroscopy (UV-vis), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy - energy dispersive X-ray spectroscopy (SEM-EDS), and electrochemical investigations demonstrated the robust formation of the sensor. The sensor exhibited improved electrochemical properties with enhanced electrochemical active area and excellent electrochemical behavior towards xanthomegnin detection with a limit of detection of 0.12 μM. The selectivity, stability, and analytical recovery studies proved the potential use of the sensor for the detection of xanthomegnin in real samples. Further, the sensor successfully detected xanthomegnin produced by the Trichophyton rubrum, the most common superficial fungus, accounting for at least 60% of all superficial fungal infections in humans. Validation studies showed satisfiable and quantifiable amount of xanthomegnin in comparison with common bench mark UV-Vis studies meant for fungal mycotoxin detection.

S1.5b The burden of mycotic keratitis in West Africa

S1.5 Mycotic keratitis, September 21, 2022, 11:00 AM - 12:30 PM BackgroundFungal infection of the cornea, known as mycotic keratitis, can cause permanent corneal scarring and perforation resulting in the loss of the eye. This paper reviews the prevalence and epidemiology of mycotic keratitis in different countries in West Africa to estimate its burden.MethodsAn exhaustive search of the literature was made on Google, PubMed, MEDfacts, Cochrane Library, and Web of knowledge using different sets of keywords, viz. mycotic keratitis, ocular fungal infection, West Arica, risk factor, prevention, etc.ResultsA study in Nigeria over a period of 4 years (1974-1977) dealt with 42 confirmed cases of mycotic keratitis with Fusarium solani as the predominant etiological agent (14 cases) followed by Penicillium citrinum (8 cases) and Aspergillus fumigates (5 cases), Candida spp (3 cases). The remaining 12 cases were that of Fusarium moniliforme, Aspergillus spp, Penicillium sp, and Cladosporium spp. The predisposing factors identified were trauma from palm tree leaves, thorns, kernels, or other plant objects, mechanical tools, and frying oil. A 10-year review (2003-2012) of 152 cases of corneal ulcers at the University of Calabar Teaching Hospital, Calabar, Nigeria revealed only 2 (2.9%) cases due to Aspergillus sp, many patients in this study were farmers. Other studies from Nigeria only mentioned the prevalence of keratitis without any mention of fungal etiology. Of the two studies from Ghana, the one conducted in 1999 showed the predominant agents Fusarium spp. (52.3%) and Aspergillus spp. (15.3%), in the other one conducted in 1999-2001, these agents were represented by 42.2% and 17.4% respectively. In another prospective study of suppurative corneal ulcers in 290 cases in Ghana (June 1999-May 2001), the etiological agents identified in culturally proven 77 (85.5%) cases of mycotic keratitis were Fusarium spp-46, A. flavus-9, A. fumigates-7, A. niger-1, A. nidulans-1, and Aspergillus sp-1 A Siera Leonian study of cases of suspected infectious ulcerative keratitis from January 2005 to January 2006) detected 35.6% of mycotic keratitis and 13.7% of mixed fungal and bacterial etiology. A study on the burden of serious fungal infections in Togo mentioned an annual incidence of 951 cases of mycotic keratitis but no details of fungal etiology were mentioned.ConclusionInvestigators have estimated the annual global incidence of fungal keratitis at over 1 million cases. Reports of cases reported from some countries represent only a tip of the true burden of mycotic keratitis in West Africa. There is a need for comprehensive surveys (involving collaboration between ophthalmologists and microbiologists) of mycotic keratitis in representative communities in collaboration with primary health centers and hospitals in different countries. It should be possible to produce a combined antifungal antibacterial preparation for widespread and immediate prophylactic first-aid use after corneal trauma, especially in rural areas.

P257 Amplified fragment length polymorphism fingerprinting supports the absence of correlation of genotype with clinical phenotype or source of the isolate in Aspergillus flavus infections

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PMObjectives Aspergillus flavus accounts for ∼ 10% of bronchopulmonary aspergillosis and is the second leading etiological agent of invasive aspergillosis worldwide. It is the commonest cause of fungal rhinosinusitis and ocular mycoses in tropical countries including India. We report amplified fragment length polymorphism genotyping of a set of clinical and environmental isolates to unravel the genetic diversity of A. flavus in India and to further determine correlation between isolate genotype and the source/clinical phenotype of the Aspergillus infection.MethodsTwo sets of morphologically identified isolates of A. flavus from clinical (n = 71) and environmental sources (n = 22) were included in the study using a stratified random sampling method. Clinical strains were isolated from lower respiratory tract specimens (n = 22), sinus and sino-nasal biopsies (n = 25), corneal samples (n = 12), and others (n = 12). Environmental strains were isolated from different niches like air, soil, and infected crop samples. Aspergillus fumigatus F145 was used as an out-group. DNA was extracted from the fungal broth culture following the method of Lee et al. AFLP was done as per an earlier described method using HpyCH41V and Mse1 (New England BioLabs) for restriction digestion followed by selective amplification of restriction-digested products with 1 mm HpyCH4 IV primer with one selective residue (5-Flu-GTA-GACTGCGTACCCGTC-3’), 1 mm MseI primer with four selective residues (5-GATGAGTCCTGACTAATGAA). Fingerprint data was analyzed in BioNumerics software version 7.6 (Applied Maths, Belgium). The phylogenetic tree was constructed using Pearson's Correlation coefficient. An AFLP genotype was assigned to a cluster using an arbitrary cut-off value of ≥90% fingerprint similarity. The distribution of genotypes among different categories was analyzed by Fisher's exact test or Pearson's χ 2 goodness of fit test with Yates correction factor as appropriate and two-tailed P-values of <.05 were considered statistically significant.ResultsThe analyses revealed a total of 16 AFLP genotypes with 5 major clusters (≥ 5 isolates) reflecting the extent of genetic diversity in A. flavus. Genotype VIII encompassed predominantly clinical isolates (P <.01) and genotype XI with majority of isolates from environmental sources (P <.0001). The strains which were isolated from invasive and non-invasive forms or from different sites (pulmonary, sinus, and ocular) did not diverge into separate or unique clusters. Although the genotypes had an asymmetric distribution in different clinical presentations as revealed by the χ2 goodness of fit test, none of the genotypes was exclusively responsible for causing a particular infection. Isolates from the north zone of India shared genotypes with those from the southern region of the country. Three isolates formed a separate genotype XVI and diverged from the A. flavus cluster by 42% fingerprint similarity. Partial β-tubulin and calmodulin gene sequencing-based phylogeny reconstruction placed those three isolates in A. tamarii clade of the A. flavus species complex.Conclusions: This study suggests that every genotype of A. flavus has the potential of causing an allergic, non-invasive or invasive infection. Further, A. flavus sensu stricto was predominantly (97%) isolated from clinical specimens revealing the majority of infections/colonization are caused by this species compared to other members in the Flavi complex.

Aspergillus Endophthalmitis: Epidemiology, Pathobiology, and Current Treatments.

Fungal endophthalmitis is one of the leading causes of vision loss worldwide. Post-operative and traumatic injuries are major contributing factors resulting in ocular fungal infections in healthy and, more importantly, immunocompromised individuals. Among the fungal pathogens, the Aspergillus species, Aspergillus fumigatus, continues to be more prevalent in fungal endophthalmitis patients. However, due to overlapping clinical symptoms with other endophthalmitis etiology, fungal endophthalmitis pose a challenge in its diagnosis and treatment. Hence, it is critical to understand its pathobiology to develop and deploy proper therapeutic interventions for combating Aspergillus infections. This review highlights the different modes of Aspergillus transmission and the host immune response during endophthalmitis. Additionally, we discuss recent advancements in the diagnosis of fungal endophthalmitis. Finally, we comprehensively summarize various antifungal regimens and surgical options for the treatment of Aspergillus endophthalmitis.

Microbiological Profiles of Ocular Fungal Infection at an Ophthalmic Referral Hospital in Southern China: A Ten-Year Retrospective Study

PurposeThis study aims to assess the testing methods used to detect fungal pathogens as well as the pathogenic profiles and drug susceptibility among fungal isolates from ocular sources collected in a tertiary eye hospital.MethodsThe laboratory test records of patients with suspected ocular fungal infection from January 2010 to December 2019 at a tertiary eye care center in southern China were retrospectively evaluated. The isolated pathogens identified by smear examination and culture combined with microscopy were analyzed. For 2017–2019 fungal isolates, their antifungal susceptibilities to four antifungal agents were evaluated.ResultsA total of 22,233 specimens (16,315 for culture and 5918 for direct smear examination) from 16,209 individuals were assessed, and 3317 specimens (2169 for culture and 1148 for smear examination) from 2395 patients had confirmed fungal infection. The mean age of patients was 50.6±14.2 years and 63.4% were male. The positive rate of smear examination was 19.4% and significantly higher than 13.3% of fungal culture (p< 0.001). Of 5812 patients who were simultaneously examined for culture and smear staining, 897 (15.43%) had positive findings for fungi. Among the 2420 positive findings, 2138 (88.3%) were from the cornea, and 133 (5.5%) were from intraocular samples. Fusarium spp. (40.5%) and Aspergillus spp. (22.0%) were the major fungal genera among the molds, whereas Candida spp. (4.6%) constituted the major yeast. Fusarium spp. had a lower antifungal susceptibility than Aspergillus spp. against voriconazole and amphotericin. And yeast spp. had the highest susceptibility to caspofungin.ConclusionThis study provided a 10-year assessment of fungi in ocular infections in southern China, giving support to epidemiological understanding and guiding empiric antimicrobial therapy.

Development and Optimization of Hyaluronic Acid-Poloxamer In-Situ Gel Loaded with Voriconazole Cubosomes for Enhancement of Activity against Ocular Fungal Infection.

Fungal eye infections are largely disseminated, especially in developing countries where they may leave over half a million people blind per year. The current study aims to boost the voriconazole antifungal efficiency via loading it as cubosomes (VZ-Cub) into hyaluronic acid and poloxamer-based ocular in situ gel. VZ-Cub were fabricated applying Box-Behnken design and employing phytantriol, poloxamer F127, and VZ amounts as independent variables. The produced nano vesicles were evaluated for the dependent variables of particle size (PS), entrapment efficiency (EE%), and transcorneal steady-state flux (Jss) of the VZ, and, the obtained optimal VZ-Cub was loaded into an in situ gel base to enhance its ocular residence time. The in situ gel formulation was tested for its gelation temperature, drug release behavior, transcorneal permeation effects, and antifungal activity. The optimized VZ-Cub consisted of 100 mg of phytantriol, 60 mg of poloxamer F127, and 21 mg of VZ. This formulation led to a minimum PS of 71 nm, an EE% of 66%, Jss value of 6.5 µg/(cm2·min), and stability index of 94 ± 2%. The optimized VZ-Cub-loaded in situ gel released 84% VZ after 12 h and yielded a 4.5-fold increase in drug permeation compared with the VZ aqueous dispersion. The antifungal activity, which was obtained by measuring the fungal growth inhibition zones, revealed that the VZ-Cub-loaded in situ gel formulation had a 3.89-fold increase in antifungal activity compared with the VZ dispersion. In summary, an ocular in situ gel loaded with VZ-Cub could be an effective novel nano-paradigm with enhanced transcorneal permeation and antifungal properties.

Inhibition of Galectin-3 Impairs Antifungal Immune Response in Fungal Keratitis.

Galectin-3 is one of the galectin family members which are master regulators of immune homeostasis, especially in infectious diseases. However, its mechanism of immune regulation in fungal keratitis has not been thoroughly studied. Our study is aimed at clarifying the role of galectin-3 in the fungal keratitis mouse model in vivo, thereby providing a new biomarker of antifungal therapy. In our study, aspergillus, the most common pathogenic fungi of fungal keratitis, was identified and isolated by corneal tissue fungus culture. Then, the RNA expression levels of galectin family members in corneas of the mouse model with aspergillus fumigatus keratitis were screened by transcriptome sequencing (RNA-seq). The expression of the galectin-3 was detected by quantitative real-time Polymerase Chain Reaction (qPCR), enzyme-linked immunosorbent assay (ELISA), and immunofluorescence in the corneal tissue of the fungal keratitis mouse model. Recruitment of neutrophils and the co-immunofluorescence of galectin-3 and related markers in corneal tissue were determined by flow cytometry analysis and immunofluorescence staining. The regulatory role of galectin-3 for proinflammatory cytokines and neutrophils was validated by the knockout mouse model. Galectin-3 knockout deteriorated the condition for the inhibition of galectin-3 was benefecial for fungi to survive and thrive in corneal lesions. These results demonstrated that in the ocular fungal infection, galectin-3 is capable of regulating the pathogenesis of fungal keratitis by modulating neutrophil recruitment. The deterioration of fungal keratitis and increased fungal load in corneal lesions of galectin-3 knockout mice proved the regulatory role of galectin-3 in fungal keratitis. In conclusion, galectin-3 is going to be an essential target to modulate neutrophil recruitment and its related antifungal immune response in fungal keratitis.

A hospital-based observational comparative study of efficacy of intracameral voriconazole and oral ketoconazole in deep keratomycosis

Background: Fungal keratitis, one of the most common causes of ocular mycosis, is the second most common cause of blindness in the world, after cataracts. The aim of the study was to compare the efficacy of conventional topical, systemic medications and intracameral voriconazole injection in visual and structural outcomes in keratomycosis. Material and methods: We conducted a hospital-based observational study of 45 patients of 45 eyes with smear-positive fungal keratitis. Patients were categorized into three groups: Group I received systemic topical with oral ketoconazole 200 mg, Group II — topical medications with intracameral voriconazole 50 μgm/0.1 mL, Group III — topical medications with both oral ketoconazole 200 mg and intracameral voriconazole 50 μgm/0.1 mL. Results: The common fungal organism is identified as Fusarium. The mean final visual acuity (VA) was 1.25 ± 0.32, 1.47 ± 1.05, and 1.22 ± 0.37 logMAR in Group I, group II, and Group III, respectively. The mean improvement in VA was 0.33 ± 0.07, 0.01 ± 0.71, and –0.19 ± 0.02 logMAR without significant change (p = 0.9). There was a significant difference in VA between the final postoperative follow-up period and baseline in Group I cases (p = 0.0019). Whereas no difference in VA between the final postoperative follow-up period and baseline in either Group II (p = 0.0671) or Group III (p = 0.1505) cases. The difference in time between the disappearance of hypopyon and the mean time to infection healing was not statistically significant (p = 0.1). Three cases in each group were perforated, and keratoplasty was performed. These perforated cases did not show culture positive. Histopathology identified the isolated organisms as Aspergillus species (n = 3) and Fusarium species (n = 2) in the corneal buttons. Conclusion: The differences in VA between the three methods were not statistically significant, indicating no treatment method superior to others (inter-group). However, in Group I, there was a significant difference in VA between the final postoperative follow-up period and baseline (p = 0.0019). There was no difference in VA between these time intervals in either Group II (p = 0.0671) or Group III (p = 0.1505). Within-group or intra-group analysis reveals that the Group I method is more effective for VA. The success rate of the method depended cumulatively on the duration of intracameral voriconazole in the anterior chamber, non-drainage of hypopyon, and individual clinical response.