Ocular infections caused by Candida species: Type of species, in vitro susceptibility and treatment outcome

The Effectiveness and Safety of Intravitreal Injections of Voriconazole in the Treatment of Fungal Endophthalmitis: A Systematic Review

Background: Fungus endophthalmitis is a rare and serious infection that is treated with systemic and topical antifungal drugs. There is no clear consensus on the treatment of fungal endophthalmitis with intravitreal injections (IVIs) of voriconazole. This systematic review aims to summarize the literature on IVIs of voriconazole for fungal endophthalmitis. Methods: We conducted a systematic review of the literature to determine the effectiveness and safety of IVIs of voriconazole in the treatment of fungal endophthalmitis. We searched databases such as PubMed and Embase using the following search terms "Endophthalmitis" AND "Intravitreal Injections" AND "Voriconazole" with date limits of January 1, 1900, to December 31, 2022. We included all reports on humans, which described clinical outcomes of IVIs of voriconazole in the treatment of fungal endophthalmitis, including randomized controlled trials (RCTs) and case series. A descriptive synthesis of the data was conducted with a pooling of data for interventions. Results: One RCT and 21 retrospective studies were analyzed in this review. In these reports, a wide range of heterogeneous treatment regimens was used, including IVI in combination with other drugs, systemic therapy in combination with other agents, and surgery. Combined with other treatments, intravitreal voriconazole results in a favorable anatomical and clinical cure that was well tolerated. Conclusions: Reports on IVIs of voriconazole for fungal endophthalmitis demonstrate a heterogeneous approach to treatment. Of these, IVIs of voriconazole in anatomical and clinical outcomes appeared to be highly effective, although more data on its safety are needed.

The Role of Biofilms in Contact Lens Associated Fungal Keratitis

Biofilm formation is an important microbial strategy for fungal pathogens, such as Fusarium, Aspergillus, and Candida, to establish keratitis in patients wearing soft contact lenses. Despite the well-documented 2006 outbreak of Fusarium keratitis that eventually led to the withdrawal of the Bausch & Lomb multipurpose lens care solution ReNu with MoistureLoc ("MoistureLoc") from the global market, contact lens care systems and solutions currently available on the market do not specifically target fungal biofilms. This is partially due to the lack of recognition and understanding of important roles that fungal biofilms play in contact lens associated fungal keratitis (CLAFK). This review aims to reemphasize the link between fungal biofilms and CLAFK, and deepen our comprehension of its importance in pathogenesis and persistence of this medical device-related infection.

A rare ocular complication of septicemia: a case series report and literature review

BACKGROUND

Septicemia that leads to ocular involvement mostly presents as endophthalmitis or panophthalmitis. Contrarily, septicemia without intraocular involvement, known as hematogenous orbital cellulitis (HOC), involves only the orbit and is an extremely rare complication of septicemia and a rare type of orbital cellulitis.

CASE PRESENTATION

Four male patients with septicemia presented with orbital involvement without intraocular infection were described in this study. They were 22 (case 1), 15 (case 2), 79 (case 3), and 30 (case 4) years old, with a mean age of 29.75 years. All patients were immunocompromised except for case 2. Cases 1 and 3 had a history of steroid use, whereas case 4 was in a post-chemotherapy myelosuppression phase. Septicemia in case 1 was community-acquired, cases 3 and 4 were hospital-acquired, and case 2 was secondary to acne squeezing. Blood cultures from cases 1, 2, and 3 were positive for Candida albicans, methicillin-resistant Staphylococcus aureus, and Klebsiella pneumoniae, respectively. Case 4 had negative cultures; however, next-generation sequencing reported the presence of Enterococcus faecalis and Rhizopus oryzae. Case 1 had right eye involvement, and both eyes were involved in the other three cases. According to Chandler's classification, case 1 was type 2, case 2 was type 2 (OD) and type 4 (OS), and cases 3 and 4 were type 1 orbital infections. All patients had eyelids erythema, and cases 1 and 2 had mildly decreased visual acuity, proptosis, and painful and restricted ocular motility. Hospital stays ranged from 13 to 43 days (mean, 24 days). All patients received systemic antibiotic therapy based on drug sensitivity and next-generation sequencing results, in combination with multidisciplinary treatment, resulting in complete recovery of ocular and systemic signs and symptoms; no ocular surgical interventions were performed. Extraocular muscle palsy was the last symptom to resolve.

CONCLUSION

HOC is predominantly seen in immunocompromised individuals with a high proportion of hospital-acquired infections and positive cultures for pathogens. Infection control using systemic antibiotics targeted at the causative organism guarantees a favorable prognosis.

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.

Molecular characterization of fungal endophthalmitis and keratitis caused by yeasts

Candida species are the most common causes of sight-threatening fungal ocular infections in temperate regions of the world. Despite their relevance, little is known about the emergence of novel species and the molecular epidemiology of these infections. Here, we molecularly characterized 38 yeast isolates collected from patients diagnosed with endophthalmitis or keratitis at Massachusetts Eye and Ear from 2014 to 2021. Sequencing of the ITS1-5.8S-/ITS2 regions demonstrated that this population of yeasts was dominated by Candida spp. (37 out of 38; 97%), with 58% of the cases caused by C. albicans (n = 22) and the remaining by emerging non-albicans species, predominantly by C. parapsilosis (n = 8) and C. dubliniensis (n = 6). One isolate each was identified as C. tropicalis and Clavispora lusitaniae. Interestingly, all C. dubliniensis were isolated from endophthalmitis and most C. parapsilosis from keratitis. Multilocus sequence typing analysis of C. albicans showed a prevalence of CC-1 isolates that has DST69 as the putative founder, with 64% of them belonging to this clonal complex (CC). Isolates grouped within this cluster were more predominant in endophthalmitis (10 out of 14; 71%). One C. albicans CC-1 isolate was multi-azole resistant. In conclusion, we observed that nearly half of the ocular infections caused by yeasts are associated with C. albicans, with evidence for the emergence of non-albicans species that are differentially enriched in distinct ocular niches. Candida albicans isolates clustered within the predominant CC-1 group were particularly more common in endophthalmitis, demonstrating a potential pattern of ocular disease enrichment within this clade.

Dual Drug Loaded Lipid Nanocarrier Formulations for Topical Ocular Applications

Introduction

Untreated ocular infections can damage the unique fine structures of the eye with possible visual impairments and blindness. Ciprofloxacin (CIP) ophthalmic solution is prescribed as first-line therapy in ocular bacterial infections. Natamycin (NT) ophthalmic suspension is one of the progenitors in ocular antifungal therapy. Nanostructured lipid carriers (NLCs) have been widely examined for ocular penetration enhancement and distribution to deeper ocular tissues. The objective of the current study was to prepare NLCs loaded with a combination of CIP and NT (CIP-NT-NLCs) and embed them in an in-situ gelling system (CIP-NT-NLCs-IG). This novel formulation will target the co-delivery of CIP and NT for the treatment of mixed ocular infections or as empirical treatment in case of limited access to healthcare diagnostic services.

Methods

CIP-NT-NLC and CIP-NT-NLC-IG formulations were evaluated based on physicochemical characteristics, in vitro release, and ex vivo transcorneal permeation studies and compared against commercial CIP and NT ophthalmic eye drops.

Results and Discussion

NLCs formulation (0.1% CIP and 0.3% NT) showed particle size, polydispersity index, and zeta potential of 196.2 ± 1.2 nm, 0.43 ± 0.06, and −28.1 ± 1.4 mV, respectively. Moreover, CIP-NT-NLCs showed entrapment efficiency of 80.9 ± 2.9 and 98.7 ± 1.9% for CIP and NT, respectively. CIP-NT-NLCs-IGformulation with 0.2% w/v gellan gum demonstrated the most favorable viscoelastic characteristics for ocular application. CIP-NT-NLCs and CIP-NT-NLCs-IG formulations exhibited a sustained release pattern for both drugs over 24 h. Moreover, CIP-NT-NLCs and CIP-NT-NLC-IG formulations showed 4.0- and 2.2-folds, and 5.0- and 2.5-folds enhancement in ex vivo transcorneal permeability of CIP and NT, respectively, compared to the control formulations.

Conclusion

The results suggest that this dual nanoparticulate-based in-situ gelling drug delivery system can serve as a promising topical delivery platform for the treatment of ocular infections.

A systematic review on distribution and antifungal resistance pattern of Candida species in the Indian population

The emergence of antifungal drug resistance in Candida species has led to increased morbidity and mortality in immunocompromised patients. Understanding species distribution and antifungal drug resistance patterns is an essential step for novel drug development. A systematic review was performed addressing this challenge in India with keywords inclusive of 'Candida', 'Antifungal Drug Resistance', 'Candidemia', 'Candidiasis' and 'India'. A total of 106 studies (January 1978-March 2020) from 20 Indian states were included. Of over 11,429 isolates, Candida albicans was the major species accounting for 37.95% of total isolates followed by C. tropicalis (29.40%), C. glabrata (11.68%) and C. parapsilosis (8.36%). Rates of antifungal resistance were highest in non-albicans Candida (NAC) species - C. haemuloni (47.16%), C. krusei (28.99%), C. lipolytica (28.89%) and C. glabrata (20.69%). Approximately 10.34% isolates of C. albicans were observed to be drug-resistant. Candida species were frequently resistant to certain azoles (ketoconazole-22.2%, miconazole-22.1% and fluconazole-21.8%). In conclusion, the present systematic review illustrates the overall distribution and antifungal resistance pattern of Candida species among the Indian population that could be helpful in the future for the formation of treatment recommendations for the region but also elsewhere.

Fungal endophthalmitis: Analysis of 730 consecutive eyes from seven tertiary eye care centers in India

PURPOSE

To evaluate the clinical and microbiological features of a large cohort of culture-confirmed fungal endophthalmitis across India.

DESIGN

Cross-sectional hospital-based retrospective medical records review.

PARTICIPANTS

Seven large tertiary eye care centers from different regions of India.

METHODS

The patient data were pooled from the electronic/physical medical records of each participating center. Fellowship-trained vitreoretinal specialists clinically managed all patients, and in-house microbiology laboratories performed all microbiology work-ups. The clinical and microbiology procedures were broadly uniform across all participating centers. The essential treatment consisted of vitreous surgery and intravitreal and systemic therapy with antifungal agents.

MAIN OUTCOME MEASURES

Clinical outcome by the causative event and causative fungus.

RESULTS

In the 2005-2020 period, seven centers treated 3830 cases of culture-proven endophthalmitis, and 19.1% (n=730) were culture-confirmed fungal endophthalmitis. It included 46.9% postoperative (87.4% post-cataract surgery), 35.6% traumatic and 17.5% endogenous endophthalmitis. The fungi included 39.0% Aspergillus (high in central, east and south zones), 15.1% Candida (high in west zone), 15.9% Fusarium (high in north and west zone). The time to symptoms was between 1w-4w in more than a third of patients except in traumatic endophthalmitis. Less than half of patients had hypopyon on presentation. Presenting visual acuity (PVA) in most patients was <20/400. Nearly all patients needed a vitrectomy and an average of two intravitreal injections of antifungal agents. At least 10% of eyes needed therapeutic keratoplasty, and up to 7% of eyes were eviscerated. Following treatment, the final (best corrected) visual acuity (FVA) was > 20/400 in 30.5% (n= 222) eyes; > 20/40 in 7.9% (n=58) eyes; and 12% (n=88) eyes lost light perception. Post-hoc analysis showed significantly more males in traumatic than post-operative (p<0.0001) and endogenous (p = 0.001) endophthalmitis; higher isolation of Candida species in endogenous than post-operative (p = 0.004) and traumatic (p<0.0001) endophthalmitis, better PVA in eyes with Candida species infection (p<0.0001) and poorer FVA in eyes with Aspergillus species infection.

CONCLUSIONS

Fungal endophthalmitis is not uncommon in India. The inclusion of antifungal agents with antibiotics as the first empirical intravitreal therapy before microbiological confirmation could be considered when fungal infection is suspected.

CLINICAL PRESENTATIONS, DIAGNOSTIC DILEMMA, AND MANAGEMENT OUTCOMES OF CHRONIC POSTOPERATIVE ENDOPHTHALMITIS CAUSED BY STEPHANOASCUS CIFERRII

PURPOSE

To report the diagnosis and management of a series of chronic postoperative endophthalmitis caused by Stephanoascus ciferrii.

METHODS

This is a retrospective consecutive case series at a tertiary eye care institute. Case records of consecutive cases of chronic postoperative endophthalmitis caused by a novel fungus S. ciferrii were analyzed. The clinical presentations, microbiologic workup including microscopy, culture, antifungal susceptibility and polymerase chain reaction for fungal DNA of clinical samples, and the clinical management were noted. The cases underwent anterior chamber tap, vitreous biopsy, core vitrectomy, and intraocular lens explantation, and the management consisted of a combination of topical and systemic therapy and intravitreal injections of antimicrobial agents.

RESULTS

The report includes four eyes of four patients. All patients were diagnosed as chronic postcataract surgery endophthalmitis, and they showed variable levels of persistent low-grade intraocular inflammation till the intraocular lens was explanted. S. ciferrii (identified by the Vitek 2 compact system) was grown in culture from one or more of the clinical samples such as vitreous, anterior chamber fluid, capular bag, and intraocular lens. Fungal DNA was detected from vitreous in one case. One isolate tested for antifungal susceptibility was resistant to amphotericin B; however, the patient responded to treatment with the drug. Good clinical outcome was achieved in all patients.

CONCLUSION

We describe successful treatment of endophthalmitis caused by S. ciferrii. A good response is obtained after pars plana vitrectomy and intraocular lens explantation.

Candida dubliniensis: A novel cause of fungal keratitis

A 45-year-old female with history of contact lens wear presented with a persistent corneal ulcer that was unresponsive to topical moxifloxacin. The patient's exam was concerning for fungal keratitis. Cultures were obtained, and the patient was started on fortified amphotericin B drops and oral voriconazole. The cultures identified Candida dubliniensis as the causative organism. The patient's exam worsened despite treatment, and the decision was made for surgery. At the time of surgery, her cornea was found to have unexpectedly perforated. She underwent cryotherapy; tectonic penetrating keratoplasty; anterior chamber tap; intracameral voriconazole, amphotericin B, and cefuroxime; and a partial conjunctival flap. Pathology from the cornea showed GMS and PAS stains positive for fungal forms. C. dubliniensis is a yeast closely related to Candida albicans that was first described in 1995 as a cause of oral candidiasis in patients with AIDS. There are a few published cases of endophthalmitis due to C. dubliniensis in the ophthalmology literature, but to our knowledge, no cases of fungal keratitis due to this organism have been reported. C. dubliniensis is a novel cause of fungal keratitis that can be difficult to identify and treat but is felt to be less virulent than C. albicans and generally susceptible to available anti-fungal therapies.

Bilateral Candida keratitis in an HIV patient with asymptomatic genitourinary candidiasis in Uganda

A 35-year-old male presented with Candida keratitis in the left eye. He was HIV positive with a CD4 of 352 cells/µL. The eye quickly deteriorated, despite intensive antifungal treatment and was eviscerated. Five months later, he re-presented with Candida keratitis in his right eye. A focal source of Candida infection was suspected and a urine culture identified Candida spp, despite being asymptomatic for genitourinary candidiasis. He was subsequently treated with good outcome (max. 75 words)

Alterations in the gut bacterial microbiome in fungal Keratitis patients

Dysbiosis in the gut microbiome has been implicated in several diseases including auto-immune diseases, inflammatory diseases, cancers and mental disorders. Keratitis is an inflammatory disease of the eye significantly contributing to corneal blindness in the developing world. It would be worthwhile to investigate the possibility of dysbiosis in the gut microbiome being associated with Keratitis. Here, we have analyzed fungal and bacterial populations in stool samples through high-throughput sequencing of the ITS2 region for fungi and V3-V4 region of 16S rRNA gene for bacteria in healthy controls (HC, n = 31) and patients with fungal keratitis (FK, n = 32). Candida albicans (2 OTUs), Aspergillus (1 OTU) and 3 other denovo-OTUs were enriched in FK samples and an unclassified denovo-OTU was enriched in HC samples. However, the overall abundances of these ‘discriminatory’ OTUs were very low (< 0.001%) and not indicative of significant dysbiosis in the fungal community inhabiting the gut of FK patients. In contrast, the gut bacterial richness and diversity in FK patients was significantly decreased when compared to HC. 52 OTUs were significantly enriched in HC samples whereas only 5 OTUs in FK. The OTUs prominently enriched in HC were identified as Faecalibacterium prausnitzii, Bifidobacterium adolescentis, Lachnospira, Mitsuokella multacida, Bacteroides plebeius, Megasphaera and Lachnospiraceae. In FK samples, 5 OTUs affiliated to Bacteroides fragilis, Dorea, Treponema, Fusobacteriaceae, and Acidimicrobiales were significantly higher in abundance. The functional implications are that Faecalibacterium prausnitzii, an anti-inflammatory bacterium and Megasphaera, Mitsuokella multacida and Lachnospira are butyrate producers, which were enriched in HC patients, whereas Treponema and Bacteroides fragilis, which are pathogenic were abundant in FK patients, playing a potential pro-inflammatory role. Heatmap, PCoA plots and functional profiles further confirm the distinct patterns of gut bacterial composition in FK and HC samples. Our study demonstrates dysbiosis in the gut bacterial microbiomes of FK patients compared to HC. Further, based on inferred functions, it appears that dysbiosis in the gut of FK subjects is strongly associated with the disease phenotype with decrease in abundance of beneficial bacteria and increase in abundance of pro-inflammatory and pathogenic bacteria.

Brown Heroin-Associated Candida albicans Ventriculitis and Endophthalmitis Treated with Voriconazole

Chronic meningitis and ventriculitis are defined as inflammatory pleocytoses in the cerebrospinal fluid (CSF) and ependyma that persists for at least 1 month without spontaneous resolution. Because the CSF communicates directly with the posterior compartments of the eye, fungal infections in the brain often cause secondary ophthalmologic complications. We report a 23-year-old male who presented to the emergency room with progressive severe headaches associated with insidious monocular vision loss. After extensive workup and a multidisciplinary team effort, the patient was diagnosed with ventriculitis and endogenous endopthalmitis. The etiology is suspected to be due to brown heroin use with secondary disseminated Candida albicans.