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PURPOSE: This study sought to identify the sources of differential performance and misclassification error among local (Indian) and external (non-Indian) corneal specialists in identifying bacterial and fungal keratitis based on corneal photography. METHODS: This study is a secondary analysis of survey data assessing the ability of corneal specialists to identify acute bacterial versus fungal keratitis by using corneal photography. One-hundred images of 100 eyes from 100 patients with acute bacterial or fungal keratitis in South India were previously presented to an international cohort of cornea specialists for interpretation over the span of April to July 2021. Each expert provided a predicted probability that the ulcer was either bacterial or fungal. Using these data, we performed multivariable linear regression to identify factors predictive of expert performance, accounting for primary practice location and surrogate measures to infer local fungal ulcer prevalence, including locality, latitude, and dew point. In addition, Brier score decomposition was used to determine experts reliability (calibration) and resolution (boldness) and were compared between local (Indian) and external (non-Indian) experts. RESULTS: Sixty-six experts from 16 countries participated. Indian practice location was the only independently significant predictor of performance in multivariable linear regression. Resolution among Indian experts was significantly better (0.08) than among non-Indian experts (0.01; P < 0.001), indicating greater confidence in their predictions. There was no significant difference in reliability between the two groups ( P = 0.40). CONCLUSION: Local cornea experts outperformed their international counterparts independent of regional variability in tropical risk factors for fungal keratitis. This may be explained by regional characteristics of infectious ulcers with which local corneal specialists are familiar.

BackgroundViral conjunctivitis (pink eye) can be highly contagious and is of public health importance. There remains significant debate whether SARS-CoV-2 can present as a primary conjunctivitis. The aim of this study was to identify pathogens associated with outpatient infectious conjunctivitis during the COVID-19 Delta surge.MethodsThis prospective study was conducted in the spring and summer months of 2021. 106 patients with acute conjunctivitis who presented to the Aravind Eye Center in Madurai, India were included. One anterior nasal swab and one conjunctival swab of each eye were obtained for each enrolled patient. Samples were subsequently processed for unbiased metagenomic RNA deep sequencing (RNA-seq). Outcomes included clinical findings and codetection of other pathogens with SARS-CoV-2 in patients with conjunctivitis.ResultsAmong the 13 patients identified with human coronavirus RNA fragments in their swabs, 6 patients had SARS-CoV-2 infection, 5 patients had coinfections of SARS-CoV-2 and human adenovirus (HAdV), 1 patient had a coinfection with human coronavirus OC43 and HAdV, and 1 patient had a coinfection of Vittaforma corneae and SARS-CoV-2. 30% had bilateral disease and symptoms on presentation. Petechial hemorrhage was noted in 33% of patients with SARS-CoV-2 infection. No patients with SARS-CoV-2 or SARS-CoV-2 and HAdV infections had subepithelial infiltrates on presentation. All patients denied systemic symptoms.ConclusionsAmong the patients presented with conjunctivitis associated with human coronavirus infection, over 50% of the patients had co-infections with other circulating pathogens, suggesting the public-health importance of broad pathogen testing and surveillance in the outpatient conjunctivitis population.

BackgroundSeasonal outbreaks of infectious conjunctivitis remain a public health issue. Determination of outbreak etiologies in the context of a worldwide pandemic may provide useful information to guide public health strategies. The aim of this study was to identify pathogens associated with outpatient infectious conjunctivitis during the COVID-19 Delta surge.MethodsThis prospective study was conducted from April 2021 to September 2021. All outpatients presenting to the Aravind Eye Center (Madurai, India) with signs and symptoms consistent with acute infectious conjunctivitis were eligible. Three swabs were obtained from each participant: one from each conjunctiva and one from the anterior nares. Samples were processed for metagenomic RNA deep sequencing (RNA-seq).ResultsSamples from 106 study participants were sequenced. The most common presenting symptoms were tearing (86%) and itching (71%). Preauricular lymphadenopathy was present in 38% of participants. 20% of participants had close contacts with similar symptoms. Systemic symptoms such as coughing, runny nose, vomiting or diarrhea were uncommonly reported. 60% of all participants used some medicated eye drops upon enrollment. 75% of study participants demonstrated infection with human adenovirus D (HAdV-D). 11% of conjunctivitis was associated with SARS-CoV-2. 15% had no definitive pathogen detected. 8% of all participants had codetection of more than one pathogen on RNA-seq.ConclusionsDuring the COVID-19 Delta surge in India, HAdV-D was the most common pathogen associated with infectious conjunctivitis. SARS-CoV-2 was the second most common associated pathogen. Seasonal surveillance may be necessary for the determination of emerging and reemerging pathogens responsible for infectious conjunctivitis.

Objectives: To determine the associated pathogen during the 2023 conjunctivitis outbreak in Vietnam Methods: RNA-sequencing was used to identify pathogens before and during the outbreak. Results: 24 patients with infectious conjunctivitis between March and October 2023 from Hai Yen Vision Institute in Vietnam were swabbed. Coxsackievirus A24v was the most common pathogen identified. Phylogenetic analysis of these strains demonstrates similarities to the Coxsackievirus identified in the 2022 India outbreak. Human adenovirus D was also circulating. Ocular findings of tearing, purulence, and itching were common in this outbreak. Conclusions: Multiple viruses can co-circulate during conjunctivitis outbreaks. Hemorrhagic conjunctivitis, commonly associated with coxsackievirus conjunctivitis, was not a common clinical sign in this outbreak. Repeat genetic surveillance, with the notable inclusion of RNA virus detection strategies, is important for outbreak detection.

PURPOSE: To determine if smartphone photography could be a useful adjunct to blindness prevalence surveys by providing an accurate diagnosis of corneal opacity. METHODS: A total of 174 patients with infectious keratitis who had undergone corneal culturing over the past 5 years were enrolled in a diagnostic accuracy study at an eye hospital in South India. Both eyes had an ophthalmologist-performed slit lamp examination, followed by anterior segment photography with a handheld digital single lens reflex (SLR) camera and a smartphone camera coupled to an external attachment that provided magnification and illumination. The diagnostic accuracy of photography was assessed relative to slit lamp examination. RESULTS: In total, 90 of 174 enrolled participants had a corneal opacity in the cultured eye and no opacity in the contralateral eye, and did not have a penetrating keratoplasty or missing photographs. Relative to slit lamp examination, the sensitivity of corneal opacity diagnosis was 68% (95%CI 58-77%) using the smartphones default settings and 59% (95%CI 49-69%) using the SLR, and the specificity was 97% (95%CI 93-100%) for the smartphone and 97% (95%CI 92-100%) for the SLR. The sensitivity of smartphone-based corneal opacity diagnosis was higher for larger scars (81% for opacities 2 mm in diameter or larger), more visually significant scars (100% for eyes with visual acuity worse than 20/400), and more recent scars (85% for eyes cultured in the past 12 months). CONCLUSION: The diagnostic performance of a smartphone coupled to an external attachment, while somewhat variable, demonstrated high specificity and high sensitivity for all but the smallest opacities.

PurposeDevelop computer vision models for image-based differentiation of bacterial and fungal corneal ulcers and compare their performance against human experts.DesignCross-sectional comparison of diagnostic performance.ParticipantsPatients with acute, culture-proven bacterial or fungal keratitis from 4 centers in South India.MethodsFive convolutional neural networks (CNNs) were trained using images from handheld cameras collected from patients with culture-proven corneal ulcers in South India recruited as part of clinical trials conducted between 2006 and 2015. Their performance was evaluated on 2 hold-out test sets (1 single center and 1 multicenter) from South India. Twelve local expert cornea specialists performed remote interpretation of the images in the multicenter test set to enable direct comparison against CNN performance.Main outcome measuresArea under the receiver operating characteristic curve (AUC) individually and for each group collectively (i.e., CNN ensemble and human ensemble).ResultsThe best-performing CNN architecture was MobileNet, which attained an AUC of 0.86 on the single-center test set (other CNNs range, 0.68-0.84) and 0.83 on the multicenter test set (other CNNs range, 0.75-0.83). Expert human AUCs on the multicenter test set ranged from 0.42 to 0.79. The CNN ensemble achieved a statistically significantly higher AUC (0.84) than the human ensemble (0.76; P < 0.01). CNNs showed relatively higher accuracy for fungal (81%) versus bacterial (75%) ulcers, whereas humans showed relatively higher accuracy for bacterial (88%) versus fungal (56%) ulcers. An ensemble of the best-performing CNN and best-performing human achieved the highest AUC of 0.87, although this was not statistically significantly higher than the best CNN (0.83; P = 0.17) or best human (0.79; P = 0.09).ConclusionsComputer vision models achieved superhuman performance in identifying the underlying infectious cause of corneal ulcers compared with cornea specialists. The best-performing model, MobileNet, attained an AUC of 0.83 to 0.86 without any additional clinical or historical information. These findings suggest the potential for future implementation of these models to enable earlier directed antimicrobial therapy in the management of infectious keratitis, which may improve visual outcomes. Additional studies are ongoing to incorporate clinical history and expert opinion into predictive models.

PurposeThe aim of this study was to report a case of human keratoconjunctivitis caused by both Newcastle disease virus (NDV) and human adenovirus.MethodsA 32-year-old-man presented with an acute unilateral keratoconjunctivitis that resolved with corneal scarring. On presentation, his conjunctival swab was collected for metagenomic sequencing.ResultsThe highest number of pathogen sequencing reads in the conjunctival sample mapped to the NDV. The second highest number of reads mapped to human adenovirus. Confirmation testing with directed reverse-transcription polymerase chain reaction also identified NDV in the specimen.ConclusionsNewcastle conjunctivitis has not been reported for more than 40 years. Mixed infections, including zoonotic pathogens, may be more common than realized.

PurposeTo develop and evaluate an automated, portable algorithm to differentiate active corneal ulcers from healed scars using only external photographs.DesignA convolutional neural network was trained and tested using photographs of corneal ulcers and scars.ParticipantsDe-identified photographs of corneal ulcers were obtained from the Steroids for Corneal Ulcers Trial (SCUT), Mycotic Ulcer Treatment Trial (MUTT), and Byers Eye Institute at Stanford University.MethodsPhotographs of corneal ulcers (n = 1313) and scars (n = 1132) from the SCUT and MUTT were used to train a convolutional neural network (CNN). The CNN was tested on 2 different patient populations from eye clinics in India (n = 200) and the Byers Eye Institute at Stanford University (n = 101). Accuracy was evaluated against gold standard clinical classifications. Feature importances for the trained model were visualized using gradient-weighted class activation mapping.Main outcome measuresAccuracy of the CNN was assessed via F1 score. The area under the receiver operating characteristic (ROC) curve (AUC) was used to measure the precision-recall trade-off.ResultsThe CNN correctly classified 115 of 123 active ulcers and 65 of 77 scars in patients with corneal ulcer from India (F1 score, 92.0% [95% confidence interval (CI), 88.2%-95.8%]; sensitivity, 93.5% [95% CI, 89.1%-97.9%]; specificity, 84.42% [95% CI, 79.42%-89.42%]; ROC: AUC, 0.9731). The CNN correctly classified 43 of 55 active ulcers and 42 of 46 scars in patients with corneal ulcers from Northern California (F1 score, 84.3% [95% CI, 77.2%-91.4%]; sensitivity, 78.2% [95% CI, 67.3%-89.1%]; specificity, 91.3% [95% CI, 85.8%-96.8%]; ROC: AUC, 0.9474). The CNN visualizations correlated with clinically relevant features such as corneal infiltrate, hypopyon, and conjunctival injection.ConclusionsThe CNN classified corneal ulcers and scars with high accuracy and generalized to patient populations outside of its training data. The CNN focused on clinically relevant features when it made a diagnosis. The CNN demonstrated potential as an inexpensive diagnostic approach that may aid triage in communities with limited access to eye care.

This study quantifies the performance of an international cohort of cornea specialists in image-based differentiation of bacterial and fungal keratitis, identifying significant regional variation and establishing a reference standard for comparison against machine learning models.

PurposeThe purpose of this article was to evaluate the impact of sample collection order on the diagnostic yield of metagenomic deep sequencing (MDS) for determining the causative pathogen in infectious keratitis.MethodsWe performed a cross-sectional diagnostic test evaluation among subjects with infectious keratitis at Aravind Eye Hospital in Madurai, India. All subjects underwent corneal scrapings of the affected eye to obtain potassium hydroxide smear, Gram stain, bacterial culture, and fungal culture, in this order. The order of MDS specimen collection relative to smear and culture samples was randomized and served as the primary predictor. Outcomes included the normalized copy number of pathogenic RNA detected by MDS, the proportion of MDS samples that were diagnostic, and the agreement of MDS results with cultures.ResultsMDS samples from 46 subjects with corneal ulcers were evaluated. MDS was positive in 33 subjects (76%) and had 74% overall agreement with culture results. There was no association between order of MDS sample collection and normalized copy number of genetic material detected (P = 0.62) or the likelihood of MDS positivity (P = 0.46). However, the likelihood of agreement between MDS and cultures decreased when MDS corneal swabs were collected after other diagnostic corneal scrapings (P = 0.05).ConclusionsThe overall yield of MDS for detecting the cause of infectious keratitis was not affected by sample collection order. However, diagnostic agreement between MDS and cultures decreased when MDS samples were collected after other specimens. Additional investigation is warranted to determine whether this represents increased sensitivity of MDS compared with cultures or higher susceptibility to contaminants.

BackgroundAcanthamoeba keratitis is challenging to treat and thought to result in poor outcomes, but very few comparative studies exist to assess whether ulcers caused by Acanthamoeba are worse than those caused by bacteria or fungus.MethodsIn a retrospective cohort study, all cases of smear- or culture-proven Acanthamoeba keratitis diagnosed from January 2006 to June 2011 at an eye hospital in South India were identified from the microbiology database. Random samples of the same number of cases of bacterial and fungal keratitis, matched by year, were identified from the same database in order to compare outcomes between the three types of organism. The main outcomes were the time until the following events: re-epithelialization, discontinuation of antimicrobials, perforation/keratoplasty, elevated intraocular pressure, and new cataract.ResultsThe median time until re-epithelialization was 113 days for Acanthamoeba keratitis, 30 days for fungal keratitis, and 25 days for bacterial keratitis, and the median time until discontinuation of antimicrobial therapy was 100 days for Acanthamoeba keratitis, 49 days for fungal keratitis, and 40 days for bacterial keratitis. Compared to the other two organisms, Acanthamoeba ulcers took significantly longer to re-epithelialize (adjusted HR 0.4, 95% CI 0.3 to 0.6 relative to bacterial ulcers and HR 0.3, 95% CI 0.2 to 0.5 relative to fungal ulcers; overall p

PurposeAcanthamoeba keratitis often is refractory to medical and surgical therapy, primarily because of the remarkable resilience of Acanthamoeba cysts. In this study, we directly compared the cysticidal activity and potency of several candidate medical therapies in vitro.DesignExperimental study.ParticipantsIn vitro Acanthamoeba specimens obtained from 9 patients with keratitis seen at the Francis I. Proctor Foundation from 2008 through 2012.MethodsThe minimum cysticidal concentration (MCC) of povidone iodine, natamycin, and chlorhexidine was investigated using an established assay technique. The relative potency of each agent was estimated starting with concentrations commonly used in clinical practice and determining the number of two-fold dilutions required to reach the MCC. Statistical comparisons of relative potency were performed using bootstrap simulations and permutation tests.Main outcome measuresMinimum cysticidal concentration and the number of two-fold dilutions required to reach the MCC.ResultsThe MCC for chlorhexidine ranged from 3.1 to 25 μg/ml (median, 12.5 μg/ml; interquartile range [IQR], 6.25-12.5 μg/ml), the MCC for natamycin ranged from 390.6 to 3125 μg/ml (median, 390.6 μg/ml; IQR, 390.6-781.2 μg/ml), and the MCC for povidone iodine ranged from 0.3 to 78.1 μg/ml (median, 2.4 μg/ml; IQR, 0.6-9.8 μg/ml). Doses commonly used in clinical practice (povidone iodine 1%, natamycin 5%, and chlorhexidine 0.04%) were approximately 12, 7, and 5 two-fold dilutions higher than the drug's corresponding median MCC, respectively (P < 0.001, comparing 3 drugs). Povidone iodine 1% had the highest potency of the 3 medications tested, requiring more dilutions than natamycin 5% (P < 0.001) and chlorhexidine 0.04% (P < 0.001) to reach the MCC.ConclusionsAll 3 medications demonstrated in vitro cysticidal activity in each of the 9 isolates. The potency of 1% povidone iodine was greater than standard formulations of natamycin or chlorhexidine. Although its clinical efficacy is yet to be determined, povidone iodine may be considered as a potential adjuvant treatment in cases of recalcitrant Acanthamoeba keratitis.

PurposeTo determine if there is a benefit to adjuvant corneal crosslinking (CXL) and to compare natamycin versus amphotericin B for filamentous fungal keratitis.DesignOutcome-masked, 2×2 factorial design, randomized controlled clinical trial.ParticipantsConsecutive patients presenting with moderate vision loss from a smear-positive fungal ulcer at Aravind Eye Hospital, Madurai, India.MethodsStudy eyes were randomized to 1 of 4 treatment combinations using an adaptive randomization protocol. The treatment arms included (1) topical natamycin 5% alone, (2) topical natamycin 5% plus CXL, (3) topical amphotericin B 0.15% alone, and (4) topical amphotericin 0.15% plus CXL.Main outcome measuresThe primary outcome of the trial was microbiological cure at 24 hours on repeat culture. Secondary outcomes included best spectacle-corrected visual acuity (BSCVA) at 3 weeks and 3 months, percentage of study participants with epithelial healing at 3 days, 3 weeks, and 3 months, infiltrate or scar size at 3 weeks and 3 months, 3-day smear and culture, and adverse events.ResultsThose randomized to CXL regardless of medication (topical natamycin or amphotericin) had 1.32-fold increased odds of 24-hour culture positivity, although this was not statistically significant (95% confidence interval [CI], 0.57-3.06; P = 0.51). We were also unable to find a difference in 24-hour culture positivity between those randomized to amphotericin and those randomized to natamycin when evaluating as a group regardless of whether or not they received CXL (coefficient 1.10; 95% CI, 0.47-2.54; P = 0.84). The BSCVA was approximately 0.22 logarithm of the minimum angle of resolution (logMAR) (2.2 Snellen lines) worse on average at 3 weeks among those receiving CXL regardless of medication (95% CI, -0.04 to 0.40; P = 0.04) and 0.32 logMAR (3.2 Snellen lines) worse visual acuity at 3 months after controlling for baseline visual acuity (95% CI, 0.03-0.54; P = 0.02). There was no difference in infiltrate or scar size, percentage of epithelialized or adverse events when comparing CXL with no CXL or the 2 topical medications.ConclusionsThere appears to be no benefit of adjuvant CXL in the primary treatment of moderate filamentous fungal ulcers, and it may result in decreased visual acuity.

PurposeTo compare longitudinal outcomes of visual acuity after fungal corneal ulcers with those of bacterial ulcers.DesignProspective cohort study.MethodsThis study was conducted in a tertiary eye hospital in South India. The population consisted of 100 of 152 individuals whose fungal or bacterial keratitis had been diagnosed 4 years prior and had been enrolled in 1 of 2 concurrent randomized trials. Causative organisms of infectious keratitis were either bacterial or fungal. Presenting visual acuity consisted of best spectacle corrected visual acuity (BSCVA) and hard contact lens-corrected visual acuity (CLVA).ResultsFifty study participants with prior fungal keratitis and 50 with prior bacterial keratitis were enrolled. Four years after treatment for keratitis, participants' presenting vision in the better eye was worse than 20/60 for 12 individuals (24.0%) in the fungal group and 10 individuals (20.0%) in the bacterial group. Median BSCVA in the affected eye at the 4-year visit in the fungal group was similar to that in the bacterial group (Snellen equivalent, 20/32 for each), although vision worse than 20/400 was more common in the fungal ulcer group after spectacle correction (odds ratio [OR] 4.19; 95% confidence interval [CI], 1.11-15.8) and contact lens correction (OR, 5.74; 95% CI, 1.37-24.1).ConclusionsIn this South Indian population with a previous episode of fungal or bacterial keratitis, correctable bilateral visual impairment was common. Although long-term visual outcomes were, on average, similar between fungal and bacterial ulcers, fungal ulcers were more likely to produce severe visual impairment.

PurposeThe etiology of conjunctivitis is often misdiagnosed. An ideal diagnostic test would identify all possible infectious causes. In this study, we apply unbiased metagenomic RNA deep sequencing (MDS) to identify pathogens causing conjunctivitis.DesignMolecular study of prospectively collected conjunctival swabs from patients with presumed infectious conjunctivitis.ParticipantsPatients with presumed acute infectious conjunctivitis.MethodsConjunctival swabs were collected from patients presenting with acute conjunctivitis. Swabs were processed for MDS. Pathogens were identified using a rapid computational pipeline to analyze the nonhost sequences obtained from MDS. Differential gene expression analysis was performed to evaluate for host transcriptome signatures for infectious types. Clinical samples were deidentified, and laboratory personnel handling the samples and interpreting the data were masked.Main outcome measuresPathogens and differential transcripts identified by MDS.ResultsMetagenomic RNA deep sequencing detected pathogens in 86% (12/14) of the patients tested. Swabs from 10 of 14 patients were positive for human adenovirus (HAdV) while swabs from 2 of 14 patients were positive for Vittaforma corneae (a parasitic fungal species of the microsporidia group). Samples positive for HAdV by RNA-seq were independently verified in a CLIA-certified laboratory. Pathogen-directed polymerase chain reaction confirmed the presence of V. corneae genome in the samples positive by RNA-seq. Local host transcriptome analysis identified 12 differentially expressed genes that provided distinct expression signatures for patients infected with HAdV compared with V. corneae.ConclusionsMetagenomic RNA deep sequencing can reliably detect and quantify common and rare pathogens causing conjunctivitis, and identify strains. The unbiased nature of metagenomic RNA deep sequencing allowed an expanded scope of pathogen detection, including fungal species not commonly associated with acute conjunctivitis. In addition, the identification of infection type-specific local host transcriptome signatures may allow for pathogen detection even when the pathogen load is too low for direct identification.

Abstract Background Aspergillus flavus, one of the causative agents of human fungal keratitis, can be phagocytosed by human corneal epithelial (HCE) cells and the conidia containing phagosomes mature into phagolysosomes. But the immunological responses of human corneal epithelial cells interacting with A. flavus are not clear. In this study, we report the expression of immune response related genes of HCE cells exposed to A. flavus spores using targeted transcriptomics. Methods Human corneal epithelial cell line and primary cultures were grown in a six-well plate and used for coculture experiments. Internalization of the conidia was confirmed by immunofluorescence microscopy of the colocalized endosomal markers CD71 and LAMP1. Total RNA was isolated, and the quantity and quality of the isolated RNA were assessed using Qubit and Bioanalyzer. NanoString nCounter platform was used for the analysis of mRNA abundance using the Human Immunology panel. R-package and nSolver software were used for data analysis. KEGG and FunRich 3.1.3 tools were used to analyze the differentially expressed genes. Results Different morphotypes of conidia were observed after 6 h of coculture with human corneal epithelial cells and found to be internalized by epithelial cells. NanoString profiling showed more than 20 differentially expressed genes in immortalized human corneal epithelial cell line and more than ten differentially expressed genes in primary corneal epithelial cells. Distinct set of genes were altered in their expression in cell line and primary corneal epithelial cells. KEGG pathway analysis revealed that genes associated with TNF signaling, NF-KB signaling, and Th17 signaling were up-regulated, and genes associated with chemokine signaling and B cell receptor signaling were down regulated. FunRich pathway analysis showed that pathways such as CDC42 signaling, PI3K signaling, and Arf6 trafficking events were activated by the clinical isolates CI1123 and CI1698 in both type of cells. Conclusions Combining the transcript analysis data from cell lines and primary cultures, we showed the up regulation of immune defense genes in A. flavus infected cells. At the same time, chemokine signaling and B cell signaling pathways are downregulated. The variability in the expression levels in the immortalized cell line and the primary cultures is likely due to the variable epigenetic reprogramming in the immortalized cells and primary cultures in the absence of any changes in the genome. It highlights the importance of using both cell types in host-pathogen interaction studies.

OBJECTIVE:To compare oral voriconazole vs placebo in addition to topical antifungals in the treatment of filamentous fungal keratitis. DESIGN:Non-prespecified, secondary case-control analysis from a multicenter, double-masked, randomized placebo-controlled clinical trial. METHODS:Study Participants: Patients with smear-positive filamentous fungal ulcers and visual acuity of 20/400 or worse who eventuated to therapeutic penetrating keratoplasty (TPK). INTERVENTION:Study participants were randomized to oral voriconazole vs oral placebo; all received topical antifungal drops. MAIN OUTCOME MEASURES:TPK button culture positivity. RESULTS:A total of 95 of 194 (49.5%) study participants enrolled at Madurai, Coimbatore, or Pondicherry, India eventuated to TPK in an average of 20.9 days (standard deviation 15.2 days, range 2-71 days). TPK button cultures were available for 67 of 95 (71%) of the TPKs performed and were positive for filamentous fungus in 45 of 67 (67%) cases. For each 1-day increase in the time to TPK there was 0.94-fold decreased odds of fungal culture positivity (95% confidence interval [CI] 0.90-0.98, P = .005). Those randomized to oral voriconazole had 1.26-fold increased odds of TPK button culture positivity after controlling for time to TPK and baseline organism, but this was not statistically significant (95% CI 0.32-4.87; P = .74). Those who underwent TPK for lack of response to medical therapy were 10.64-fold more likely to be culture positive than if the indication for surgery was perforation and this was statistically significant (95% CI 2.16-51.70; P = .003). CONCLUSIONS:There appears to be no benefit to adding oral voriconazole to topical antifungal agents in the treatment of severe filamentous fungal ulcers. Infection rather than inflammation appears to be the reason for the worsening clinical picture in many of these patients.

PURPOSE:To identify fungal keratitis patients who are at risk of a poor outcome and may benefit from closer follow-up or more aggressive treatment. DESIGN:Secondary analysis of randomized clinical trial data. METHODS:We compared the clinical outcomes of patients who had positive 6-day fungal cultures with those who did not, using backward stepwise regression with covariates for all baseline clinical characteristics. SUBJECTS:Patients presenting with a smear-positive filamentous fungal ulcer and visual acuity of 20/400 or worse, and who subsequently had a 6-day fungal culture performed at the Aravind Eye Care system (India), Lumbini Eye Hospital (Nepal), or Bharatpur Eye Hospital (Nepal). MAIN OUTCOME MEASURES:The primary outcome is rate of corneal perforation and/or the need for therapeutic penetrating keratoplasty. Secondary outcomes include 3-month best spectacle-corrected visual acuity (BSCVA), 3-month infiltrate and/or scar size, and rate of re-epithelialization. RESULTS:Patients who tested positive at their 6-day culture had twice the hazard of experiencing a corneal perforation or the need for therapeutic penetrating keratoplasty (P = .002) than those who tested negative, even after controlling for baseline ulcer characteristics. These patients also had on average 0.26 logMAR lines worse BSCVA at 3 months (P = .001). Culture positivity at day 6 was not a statistically significant predictor of 3-month infiltrate/scar-size (-0.24 mm1; P = .45) or time to re-epithelialization (hazard ratio = .81; P = .31). CONCLUSIONS:Here we identify a uniquely valuable clinical tool, day 6 culture results, for the treatment of severe fungal keratitis. Risk stratification based on repeat culture positivity is an objective way to assess response to medical therapy and identify patients who are at high risk of a poor clinical outcome. This establishes a new standard of care for severe fungal keratitis management.

PurposeTo determine whether patients who had a positive repeated culture was predictive of worse clinical outcome than those who achieved microbiological cure at 6 days in the Mycotic Ulcer Treatment Trial I (MUTT-I).DesignSecondary analysis from a multicenter, double-masked, randomized clinical trial.Methodssetting: Multiple hospital sites of the Aravind Eye Care System, India.Study populationPatients with culture-positive filamentous fungal ulcers and visual acuity of 20/40 to 20/400 reexamined 6 days after initiation of treatment.InterventionCorneal scraping and cultures were obtained from study participants at day 6 after enrollment.Main outcome measuresWe assessed 3-month best spectacle-corrected visual acuity (BSCVA), 3-month infiltrate/scar size, corneal perforation, and re-epithelialization rates stratified by culture positivity at day 6.ResultsOf the 323 patients with smear-positive ulcers enrolled in MUTT-I, 299 (92.6%) were scraped and cultured 6 days after enrollment. Repeat culture positivity was 31% (92/299). Among patients who tested positive at enrollment, those with positive 6-day cultures had significantly worse 3-month BSCVA (0.39 logMAR; 95% confidence interval [CI]: 0.24-0.44; P < .001), had larger 3-month scar size (0.39 mm; 95% CI: 0.06-0.73; P = .02), were more likely to perforate or require therapeutic penetrating keratoplasty (odds ratio: 6.27; 95% CI: 2.73-14.40; P < .001), and were slower to re-epithelialize (hazard ratio: 0.33; 95% CI: 0.21-0.50; P < .001) than those with a negative 6-day culture result.ConclusionsEarly microbiological cure on culture is a predictor of clinical response to treatment.

AimsTo report trends in antibiotic resistance in cases of bacterial keratitis from a large eye hospital in South India.MethodsIn this retrospective cross-sectional study, the microbiology laboratory records of patients with infectious keratitis diagnosed at an eye hospital in South India from 2002 to 2013 were reviewed to determine the proportion with antibiotic non-susceptibility.Results3685 bacterial isolates had susceptibility testing performed over the 12-year period. The two most common organisms with resistance were Streptococcus pneumoniae (n=1204) and Pseudomonas aeruginosa (n=894). Antibiotic non-susceptibility was generally uncommon for these two organisms and no significant trends were detected over the course of the study. In contrast, Staphylococcus aureus (N=211) isolates demonstrated a significant increase in fluoroquinolone non-susceptibility over the 12-year study period. This coincided with a significant increase in methicillin-resistant S. aureus (MRSA) during the study period, though the increase in fluoroquinolone resistance was likewise seen in methicillin-sensitive S. aureus (MSSA). For example, ofloxacin resistance in MSSA increased from 11.1% in 2002 to 66.7% in 2013 (p=0.002). No trends were apparent for the aminoglycosides, cefazolin or vancomycin, for which in vitro non-susceptibility generally appeared to be low.ConclusionResistance to antibiotics was generally stable for infectious keratitis isolates from a large eye hospital in South India, except for S. aureus, which experienced a significant increase in fluoroquinolone resistance from 2002 to 2013. Fluoroquinolone antibiotics currently have poor in vitro activity against both MRSA and MSSA in South India and are therefore not the ideal therapy for Staphylococcal corneal ulcers.

The Steroids for Corneal Ulcers Trial (SCUT) was a multicenter, international study of bacterial keratitis in which 101 Pseudomonas aeruginosa infections were treated. Twenty-two of 101 P. aeruginosa isolates collected had a colony morphology characteristic of a loss-of-function mutation in lasR, the gene encoding a quorum-sensing master regulator. Ulcers caused by these 22 strains were associated with larger areas of corneal opacification, worse vision, and a lower rate of vision recovery in response to treatment than ulcers caused by the other isolates. The lasR sequences from these isolates each contained one of three nonsynonymous substitutions, and these strains were deficient in production of LasR-regulated protease and rhamnolipids. Replacement of lasR with either of the two most common lasR alleles from the SCUT isolates was sufficient to decrease protease and rhamnolipid production in PA14. Loss of LasR function is associated with increased production of CupA fimbriae, and the LasR-defective isolates exhibited higher production of CupA fimbriae than LasR-intact isolates. Strains with the same lasR mutation were of the same multilocus sequence type, suggesting that LasR-deficient, environmental P. aeruginosa strains were endemic to the area, and infections caused by these strains were associated with worse patient outcomes in the SCUT study. (This study has been registered at ClinicalTrials.gov under registration no. NCT00324168.) IMPORTANCE The LasR transcription factor is an important regulator of quorum sensing in P. aeruginosa and positively controls multiple virulence-associated pathways. The emergence of strains with lasR loss-of-function alleles in chronic disease is well described and is thought to represent a specific adaptation to the host environment. However, the prevalence and virulence of these strains in acute infections remain unclear. This report describes observations revealing that lasR mutants were common among isolates from a large, multicenter clinical study of keratitis and were associated with worse clinical outcomes than LasR-intact strains despite reduced production of LasR-regulated factors. Additionally, these lasR mutants were closely related strains or clones, as determined by molecular analysis. Because bacterial keratitis is community acquired, these data indicate infection by endemic, LasR-deficient strains in the environment. These results suggest that the conventional paradigm regarding the role for LasR-mediated regulation of virulence is more complex than previously appreciated.

Purpose: The purpose of this study is to compare the endothelial cell loss (ECL) in nanophthalmic eyes and age-matched controls undergoing cataract surgery by phacoemulsification and also to identify the risk factors influencing the endothelial cell density (ECD). This was a prospective comparative interventional case series. Methods: We enrolled 19 nanophthalmic eyes (study group) and 42 age-matched cataract controls (control group) undergoing phacoemulsification after meeting the inclusion criteria. Ocular parameters like best-corrected visual acuity, intraocular pressure, pachymetry, specular microscopy, and slit lamp findings were noted preoperatively and at month 1 and 3 postsurgery. All nanophthalmic eyes underwent cataract surgery with concomitant prophylactic posterior sclerostomy. Results: The median percentage endothelial loss in nanophthalmic eyes was 4.0 (IQR 0–23.5), 7.4 (IQR 1.0–-22.4) at 1 and 3 months postoperatively compared to 6.3 (IQR 1.7–14.1) and 6.4 (IQR 2.6–-12.1) in age controlled normal eyes (P = 0.94, P = 0.46, respectively). Linear regression analysis showed increasing age as the only variable influencing the percentage decrease in corneal ECD in the study group (P = 0.001). Nanophthalmic eyes with ACD 2.5 mm were significantly better postcataract surgery (P = 0.02 and P = 0.002, respectively). Conclusion: The percentage of ECL in nanophthalmic eyes undergoing phacoemulsification is equivalent to normal eyes. However, in the nanophthamic eyes with AC depth

ImportanceThe development of multiple triazole resistance in pathogenic filamentous fungi has become an increasing clinical concern and has been shown to increase the risk for treatment failure.ObjectiveTo determine whether antifungal resistance increased during the Mycotic Ulcer Treatment Trial I (MUTT I), as measured by minimum inhibitory concentrations (MICs) in baseline cultures.Design, setting, and participantsThis secondary analysis of a double-masked, multicenter, randomized clinical trial included patients with culture- or smear-positive filamentous fungal corneal ulcer and a baseline visual acuity of 20/40 to 20/400. Culture-positive samples with susceptibility testing were included in this analysis. The patients were treated at multiple locations of the Aravind Eye Care Hospital system in South India. Data were collected from April 3, 2010, to December 31, 2011, and analyzed from July 15 to September 1, 2015.InterventionsCorneal smears and cultures were obtained from all study participants at baseline. Susceptibility testing was performed for each culture-positive specimen.Main outcomes and measuresMinimum inhibitory concentration of voriconazole and natamycin in baseline cultures.ResultsOf 323 participants with smear-positive specimens (183 men [56.7%]; 140 women [43.3%]; median [interquartile range] age, 47 [38-56] years), fungal-positive cultures were obtained for 256 (79.3%). The MIC data were available for 221 of 323 participants (68.4%), because 35 samples had no growth during susceptibility testing. A 2.14-fold increase per year (95% CI, 1.13-4.56; P = .02) in voriconazole MICs after controlling for the infectious organism was found. This association was not found when looking at natamycin MICs of baseline cultures after controlling for the infectious organism (1.26; 95% CI, 0.13-12.55; P = .85).Conclusions and relevanceSusceptibility to voriconazole appeared to decrease during the relatively short enrollment period of the clinical trial. This decrease may be more related to increased resistance of environmental fungi rather than previous treatment with azoles, because presenting with azole treatment was not a risk factor for resistance.Trial registrationclinicaltrials.gov Identifier: NCT00996736.

ObjectiveTo assess the trends in microbiological organisms identified from corneal scrapings from patients with infectious keratitis at a tertiary care medical centre in South India.MethodsWe reviewed the records of the microbiology laboratory at Aravind Eye Hospital in Madurai, India, from 2002 until 2012. We identified the microbiological causes of all corneal ulcers from the culture and smear results, and assessed for trends in bacterial and fungal keratitis over time.ResultsOf 23 897 corneal patients with ulcer with a corneal smear from 2002 to 2012 a fungal organism was identified in 34.3%, a bacterial organism in 24.7% and no organism in 38.3%. During this period, the annual number of keratitis cases due to bacteria decreased from 677 to 412, and the annual number due to fungus increased from 609 to 863. In analyses accounting for the total number of outpatients seen each year, the decline in number of smears positive for bacteria was statistically significant (p

Interleukin 17A (IL-17) production by peripheral blood neutrophils was examined in patients with fungal keratitis and in uninfected individuals in southern India, which has high levels of airborne Aspergillus and Fusarium conidia. Il17a gene expression and intracellular IL-17 were detected in all groups, although levels were significantly elevated in neutrophils from patients with keratitis. There were no significant differences in plasma IL-17 and IL-23 between patients with keratitis and uninfected individuals; however, combined data from all groups showed a correlation between the percentage IL-17 producing neutrophils and plasma IL-23, and between plasma IL-17 and IL-6 and IL-23.

BackgroundTo determine the relationship between type three secretion genotype and fluoroquinolone resistance for P. aeruginosa strains isolated from microbial keratitis during the Steroids for Corneal Ulcers Trial (SCUT) and for two laboratory strains, PA103 and PAO1.MethodsConfirmed P. aeruginosa isolates from the SCUT were divided into exoU(+) or exoU(-). The exoU(+) strains contained the gene encoding ExoU, a powerful phospholipase toxin delivered into host cells by the type three secretion system. Isolates were then assessed for susceptibility to fluoroquinolone, cephalosporin, and aminoglycoside antibiotics using disk diffusion assays. Etest was used to determine the MIC of moxifloxacin and other fluoroquinolones. Laboratory isolates in which the exoU gene was added or deleted were also tested.ResultsA significantly higher proportion of exoU(+) strains were resistant to ciprofloxacin (p = 0.001), gatifloxacin (p = 0.003), and ofloxacin (p = 0.002) compared to exoU(-) isolates. There was no significant difference between exoU(+) or exoU(-) negative isolates with respect to susceptibility to other antibiotics except gentamicin. Infections involving resistant exoU(+) strains trended towards worse clinical outcome. Deletion or acquisition of exoU in laboratory isolates did not affect fluoroquinolone susceptibility.ConclusionsFluoroquinolone susceptibility of P. aeruginosa isolated from the SCUT is consistent with previous studies showing elevated resistance involving exoU encoding (cytotoxic) strains, and suggest worse clinical outcome from infections involving resistant isolates. Determination of exoU expression in clinical isolates of P. aeruginosa may be helpful in directing clinical management of patients with microbial keratitis.

PurposeTo assess the association between minimum inhibitory concentration (MIC) and clinical outcomes in a fungal keratitis clinical trial.DesignExperimental study using data from a randomized comparative trial.ParticipantsOf the 323 patients enrolled in the trial, we were able to obtain MIC values from 221 patients with monocular fungal keratitis.MethodsThe Mycotic Ulcer Treatment Trial I was a randomized, double-masked clinical trial comparing clinical outcomes of monotherapy with topical natamycin versus voriconazole for the treatment of fungal keratitis. Speciation and determination of MIC to natamycin and voriconazole were performed according to Clinical and Laboratory Standards Institute guidelines. The relationship between MIC and clinical outcome was assessed.Main outcome measuresThe primary outcome was 3-month best spectacle-corrected visual acuity. Secondary outcomes included 3-month infiltrate or scar size; corneal perforation and/or therapeutic penetrating keratoplasty; and time to re-epithelialization.ResultsA 2-fold increase in MIC was associated with a larger 3-month infiltrate or scar size (0.21 mm; 95% confidence interval [CI], 0.10-0.31; P < 0.001) and increased odds of perforation (odds ratio, 1.32; 95% CI, 1.04-1.69; P = 0.02). No correlation was found between MIC and 3-month visual acuity. For natamycin-treated cases, an association was found between higher natamycin MIC with larger 3-month infiltrate or scar size (0.29 mm; 95% CI, 0.15-0.43; P < 0.001) and increased perforations (odds ratio, 2.41; 95% CI, 1.46-3.97; P < 0.001). Among voriconazole-treated cases, the voriconazole MIC did not correlate with any of the measured outcomes in the study.ConclusionsDecreased susceptibility to natamycin was associated with increased infiltrate or scar size and increased odds of perforation. There was no association between susceptibility to voriconazole and outcome.

Bacterial keratitis is a leading cause of visual impairment worldwide. However, the natural history of treated bacterial keratitis has not been well characterized. We performed a secondary analysis of the Steroids for Corneal Ulcers Trial (SCUT; clinicaltrials.gov #NCT00324168) to better characterize the rate of visual acuity improvement after successful antimicrobial treatment.

PurposeWe described the change in visual acuity experienced by eyes successfully treated for bacterial keratitis.MethodsThis was a prospective cohort study of a subset of study participants who had previously enrolled in the Steroids for Corneal Ulcers Trial (SCUT). All study participants had been diagnosed with culture-proven bacterial keratitis before enrollment in SCUT and subsequently were randomized to adjunctive topical corticosteroids or placebo. During SCUT, we monitored study participants at enrollment, 3 weeks, 3 months, and 12 months. We invited a subset to complete a comprehensive eye examination approximately 4 years after enrollment in SCUT. Certified refractionists assessed best spectacle-corrected visual acuity (BSCVA) using the same protocol at each study visit.ResultsWe examined 50 SCUT participants at 4 years after enrollment. Among those in this cohort, mean logMAR BSCVA at enrollment was 0.85 (Snellen equivalent, 20/160; 95% confidence interval [CI], 0.71-0.99). On average, visual acuity improved by 2.9 logMAR lines from enrollment to 3 weeks (P < 0.001), 1.2 lines from 3 weeks to 3 months (P = 0.002), and 0.8 lines from 3 to 12 months (P = 0.01). The BSCVA did not change significantly between 12 months and 4 years (0.04-line improvement, P = 0.88). After controlling for visual acuity at enrollment, BSCVA was not significantly different between the corticosteroid and placebo groups at 4 years (P = 0.53).ConclusionsCases of bacterial keratitis may continue to demonstrate improvements in visual acuity up to 12 months following diagnosis, but further improvements are unlikely. These findings may guide the appropriate timing of surgical intervention in these patients. (ClinicalTrials.gov number, NCT00324168.).

BackgroundTo determine the relationship between type three secretion genotype and fluoroquinolone resistance for P. aeruginosa strains isolated from microbial keratitis during the Steroids for Corneal Ulcers Trial (SCUT) and for two laboratory strains, PA103 and PAO1.MethodsConfirmed P. aeruginosa isolates from the SCUT were divided into exoU(+) or exoU(-). The exoU(+) strains contained the gene encoding ExoU, a powerful phospholipase toxin delivered into host cells by the type three secretion system. Isolates were then assessed for susceptibility to fluoroquinolone, cephalosporin, and aminoglycoside antibiotics using disk diffusion assays. Etest was used to determine the MIC of moxifloxacin and other fluoroquinolones. Laboratory isolates in which the exoU gene was added or deleted were also tested.ResultsA significantly higher proportion of exoU(+) strains were resistant to ciprofloxacin (p = 0.001), gatifloxacin (p = 0.003), and ofloxacin (p = 0.002) compared to exoU(-) isolates. There was no significant difference between exoU(+) or exoU(-) negative isolates with respect to susceptibility to other antibiotics except gentamicin. Infections involving resistant exoU(+) strains trended towards worse clinical outcome. Deletion or acquisition of exoU in laboratory isolates did not affect fluoroquinolone susceptibility.ConclusionsFluoroquinolone susceptibility of P. aeruginosa isolated from the SCUT is consistent with previous studies showing elevated resistance involving exoU encoding (cytotoxic) strains, and suggest worse clinical outcome from infections involving resistant isolates. Determination of exoU expression in clinical isolates of P. aeruginosa may be helpful in directing clinical management of patients with microbial keratitis.

PurposeTo determine whether topical corticosteroids as adjunctive therapy for bacterial keratitis improves long-term clinical outcomes.DesignRandomized, placebo-controlled, double-masked clinical trial.MethodsThis multicenter trial compared 1.0% prednisolone sodium phosphate to placebo in the treatment of bacterial keratitis among 500 patients with culture-positive ulcers receiving 48 hours of moxifloxacin before randomization. The primary endpoint was 3 months from enrollment, and 399 patients were evaluated at 12 months. The outcomes examined were best spectacle-corrected visual acuity (BSCVA) and scar size at 12 months. Based on previous results, regression models with adjustments for baseline status and/or causative organism were used for analysis.ResultsNo significant differences in clinical outcomes by treatment group were seen with the prespecified regression models (BSCVA: -0.04 logMAR, 95% CI, -0.12 to 0.05, P = .39; scar size: 0.03 mm, 95% CI, -0.12 to 0.18, P = .69). A regression model including a Nocardia-treatment arm interaction found corticosteroid use associated with a mean 1-line improvement in BSCVA at 12 months among patients with non-Nocardia ulcers (-0.10 logMAR, 95% CI, -0.19 to -0.02, P = .02). No significant difference was observed in 12-month BSCVA for Nocardia ulcers (0.18 logMAR, 95% CI, -0.04 to 0.41, P = .16). Corticosteroids were associated with larger mean scar size at 12 months among Nocardia ulcers (0.47 mm, 95% CI, 0.06-0.88, P = .02) and no significant difference was identified by treatment for scar size for non-Nocardia ulcers (-0.06 mm, 95% CI, -0.21 to 0.10, P = .46).ConclusionsAdjunctive topical corticosteroid therapy may be associated with improved long-term clinical outcomes in bacterial corneal ulcers not caused by Nocardia species.

PurposeTo describe the minimum inhibitory concentration (MIC) of fungal isolates to natamycin and voriconazole, and to compare these MICs to previous ocular susceptibility studies.DesignExperimental laboratory study using isolates from a randomized clinical trial.MethodsThe Mycotic Ulcer Treatment Trial I was a randomized, double-masked, multicenter trial comparing topical natamycin and voriconazole for fungal keratitis treatment. Susceptibility testing to natamycin and voriconazole were performed according to Clinical and Laboratory Standards Institute methods. The relationship between organism and MIC was assessed. A literature review was performed to compare results to previous ocular susceptibility studies.ResultsOf the 323 patients enrolled in the trial, MICs were available for 221 (68%). Fusarium (n = 126) and Aspergillus species (n = 52) were the most commonly isolated organisms. MICs to natamycin and voriconazole were significantly different across all genera (P < .001). The MIC median (MIC50) and 90th percentile (MIC90) for natamycin were equal to or higher than voriconazole for all organisms except Curvularia species. Compared to other organisms, Fusarium species isolates had the highest MICs to voriconazole and Aspergillus flavus isolates had the highest MICs to natamycin. Our results were similar to previous reports except that the voriconazole MIC90 against Aspergillus species was 2-fold higher and the natamycin MIC90 against Aspergillus fumigatus was 4-fold higher in our study.ConclusionIn this large susceptibility study, Fusarium isolates were least susceptible to voriconazole and A flavus isolates were least susceptible to natamycin when compared to other filamentous fungi. In the future, susceptibility testing may help guide therapy if performed in a timely manner.

PurposeTo determine risk factors and clinical signs that may differentiate between bacterial, fungal, and acanthamoeba keratitis among patients presenting with presumed infectious keratitis.DesignHospital-based cross-sectional study.MethodsWe examined the medical records of 115 patients with laboratory-proven bacterial keratitis, 115 patients with laboratory-proven fungal keratitis, and 115 patients with laboratory-proven acanthamoeba keratitis seen at Aravind Eye Hospital, Madurai, India, from 2006-2011. Risk factors and clinical features of the 3 organisms were compared using multinomial logistic regression.ResultsOf 95 patients with bacterial keratitis, 103 patients with fungal keratitis, and 93 patients with acanthamoeba keratitis who had medical records available for review, 287 (99%) did not wear contact lenses. Differentiating features were more common for acanthamoeba keratitis than for bacterial or fungal keratitis. Compared to patients with bacterial or fungal keratitis, patients with acanthamoeba keratitis were more likely to be younger and to have a longer duration of symptoms, and to have a ring infiltrate or disease confined to the epithelium.ConclusionsRisk factors and clinical examination findings can be useful for differentiating acanthamoeba keratitis from bacterial and fungal keratitis.

Although belong to the same genus, Aspergillus fumigatus is primarily involved in invasive pulmonary infection, whereas Aspergillus flavus is a common cause of superficial infection. In this study, we compared conidia (the infective propagules) of these two Aspergillus species. In immunocompetent mice, intranasal inoculation with conidia of A. flavus resulted in significantly higher inflammatory responses in the lungs compared to mice inoculated with A. fumigatus conidia. In vitro assays revealed that the dormant conidia of A. flavus, unlike A. fumigatus dormant conidia, are immunostimulatory. The conidial surface of A. fumigatus was covered by a rodlet-layer, while that of A. flavus were presented with exposed polysaccharides. A. flavus harbored significantly higher number of proteins in its conidial cell wall compared to A. fumigatus conidia. Notably, β-1,3-glucan in the A. flavus conidial cell-wall showed significantly higher percentage of branching compared to that of A. fumigatus. The polysaccharides ensemble of A. flavus conidial cell wall stimulated the secretion of proinflammatory cytokines, and conidial cell wall associated proteins specifically stimulated IL-8 secretion from the host immune cells. Furthermore, the two species exhibited different sensitivities to antifungal drugs targeting cell wall polysaccharides, proposing the efficacy of species-specific treatment strategies. Overall, the species-specific organization of the conidial cell wall could be important in establishing infection by the two Aspergillus species.

PurposeTo describe temporal trends in Pseudomonas aeruginosa resistance to moxifloxacin in keratitis isolates from South India.MethodsThe Steroids for Corneal Ulcers Trial (SCUT) was a randomized, double-masked, placebo-controlled trial assessing outcomes in patients with culture positive bacterial corneal ulcers randomized to receive prednisolone phosphate or placebo. All patients received moxifloxacin, and susceptibility to moxifloxacin was measured at baseline using Etest. We investigated trends in moxifloxacin susceptibility of P. aeruginosa during 2007, 2008, and 2009 isolated in SCUT in South India.ResultsThere were 89 P. aeruginosa isolates during 2007, 2008, and 2009 in SCUT that were eligible for this study. There was an increase in the proportion of resistant isolates from 19% in 2007 to 52% in 2009 (p = 0.02, χ(2) test for trend). Logistic regression showed that there was a 2-fold increase in odds of resistance per 1 year increase during the study period (odds ratio 2.16, 95% confidence interval 1.09-4.26, p = 0.027).ConclusionsWe found a sharp increase in the proportion of isolates that were resistant to moxifloxacin from 2007 to 2009. Further work needs to be done to characterize the nature of this increase.

PurposeBacterial keratitis is a sight-threatening infection of the cornea that is one of the leading causes of blindness globally. In this report, we analyze the role of moxifloxacin susceptibility in the relationship between causative organisms and clinical outcome in bacteria keratitis.MethodsA mediation analysis is used to assess the role of moxifloxacin susceptibility in the relationship between causative organisms and clinical outcome in bacterial keratitis using data collected in a randomized, controlled trial.ResultsIn the Steroids for Corneal Ulcers Trial (SCUT), 500 corneal infections were treated with topical moxifloxacin. The outcome of 3-week best spectacle-corrected visual acuity was significantly associated with an organism (Streptococcus pneumoniae, Pseudomonas aeruginosa, etc., P = 0.008). An indirect effects mediation model suggests that MIC accounted for approximately 13% (95% confidence interval, 3%-24%, P = 0.015) of the effect of the organism on 3-week visual acuity.ConclusionsMoxifloxacin mediates the relationship between causative organisms and clinical outcome in bacterial keratitis, and is likely on the causal pathway between the organism and outcome. (ClinicalTrials.gov number, NCT00324168.).

ObjectivesTo determine whether cytotoxic and invasive Pseudomonas aeruginosa strains differentially influence clinical presentation, outcomes, or therapeutic response in bacterial keratitis.MethodsPseudomonas aeruginosa isolates from the National Eye Institute-funded Steroids for Corneal Ulcers Trial were subtyped as cytotoxic or invasive strains. The main outcome measure compared between the 2 subtypes was change in visual acuity at 3 months using Huber robust regression, adjusting for topical corticosteroid treatment.ResultsOf 101 confirmed P aeruginosa isolates from the Steroids for Corneal Ulcers Trial, 74 had a classically cytotoxic or invasive genotype. While corneal ulcers caused by genotypically invasive P aeruginosa strains were associated at presentation with significantly better visual acuity than corneal ulcers caused by genotypically cytotoxic P aeruginosa strains when adjusting for the effect of ulcer location (P= .008), invasive ulcers had improved significantly less than cytotoxic ulcers at 3 months (0.35; 95% CI, 0.04-0.66 logMAR; P= .03 [3.5-line difference]). Compared with topical moxifloxacin alone, adjunctive treatment with topical corticosteroids was associated with significantly more improvement in visual acuity in the invasive subgroup (P= .04) but was associated with less improvement in visual acuity in the cytotoxic subgroup (P= .07).ConclusionsRational profiling of differentially expressed virulence determinants (eg, cytotoxicity and invasiveness for P aeruginosa) could be used as a tool for decision making in the management of infections to optimize outcomes.

Presenting characteristics of bacterial corneal ulcers may suggest particular causative organisms, helping to guide treatment decisions before cultures become available. In this study, we analyze the association between presentation demographic and clinical characteristics, using data collected as part of a randomized, controlled clinical trial. Data for this study were collected as part of the Steroids for Corneal Ulcers Trial, a randomized, placebo-controlled, double-masked trial. All patients had a culture-proven bacterial corneal ulcer. Patient history, clinical examination, and photography were performed in a standardized fashion at enrollment. Analysis of variance or Fisher's exact test was used to compare characteristics by organism. Univariate logistic regression was used to analyze predictors of the most common organisms. Five hundred patients were enrolled in the trial, of whom 488 were included in this analysis. The most common organism was Streptococcus pneumoniae (N = 248, 51 %) followed by Pseudomonas aeruginosa (N = 110, 23 %). Compared to other organisms, P. aeruginosa was significantly associated with a larger baseline infiltrate/scar size [odds ratio (OR) 1.6, 95 % confidence interval (CI) 1.4-1.8] and deeper infiltrate (OR 2.4, 95 % CI 1.5-3.8). S. pneumoniae was significantly associated with a smaller baseline infiltrate/scar size (OR 0.8, 95 % CI 0.7-0.9) and dacryocystitis (OR 7.3, 95 % CI 4.1-13.3). Nocardia spp. were significantly associated with longer duration of symptoms prior to presentation (OR 1.4, 95 % CI 1.2-1.6), more shallow infiltrate (OR 0.3, 95 % CI 0.2-0.5), and better baseline visual acuity (OR 0.4, 95 % CI 0.2-0.65). Staphylococcus spp. were less likely to be central in location (OR 0.16, 95 % CI 0.08-0.3). Baseline characteristics of bacterial ulcers may suggest the likely etiology and guide early management.