OUTCOMES OF INFECTIOUS PANUVEITIS ASSOCIATED WITH SIMULTANEOUS MULTI-POSITIVE OCULAR FLUID POLYMERASE CHAIN REACTION.

PURPOSE: To evaluate features of infectious panuveitis associated with multiple pathogens detected by ocular fluid sampling. METHODS: Single-center, retrospective, consecutive case series of patients with aqueous/vitreous polymerase chain reaction testing with >1 positive result in a single sample from 2001 to 2021. RESULTS: Of 1,588 polymerase chain reaction samples, 28 (1.76%) were positive for two pathogens. Most common pathogens were cytomegalovirus (n = 16, 57.1%) and Epstein-Barr virus (n = 13, 46.4%), followed by varicella zoster virus (n = 8, 28.6%), Toxoplasma gondii (n = 6, 21.4%), herpes simplex virus 2 (n = 6, 21.4%), herpes simplex virus 1 (n = 6, 21.4%), and Toxocara (n = 1, 3.6%). Mean initial and final visual acuity (logarithm of the minimum angle of resolution) were 1.3 ± 0.9 (Snellen ∼20/400) and 1.3 ± 1.1 (Snellen ∼20/400), respectively. Cytomegalovirus-positive eyes (n = 16, 61.5%) had a mean final visual acuity of 0.94 ± 1.1 (Snellen ∼20/175), whereas cytomegalovirus-negative eyes (n = 10, 38%) had a final visual acuity of 1.82 ± 1.0 (Snellen ∼20/1,320) ( P < 0.05). Main clinical features included intraocular inflammation (100%), retinal whitening (84.6%), immunosuppression (65.4%), retinal hemorrhage (38.5%), and retinal detachment (34.6%). CONCLUSION: Cytomegalovirus or Epstein-Barr virus were common unique pathogens identified in multi-PCR-positive samples. Most patients with co-infection were immunosuppressed with a high rate of retinal detachment and poor final visual acuity. Cytomegalovirus-positive eyes had better visual outcomes compared with cytomegalovirus-negative eyes.

Variations in irradiation energy and rose bengal concentration for photodynamic antimicrobial therapy of fungal keratitis isolates.

The purpose is to assess the efficacy of rose bengal photodynamic antimicrobial therapy (PDAT) using different irradiation energy levels and photosensitizer concentrations for the inhibition of fungal keratitis isolates. Seven different fungi (Aspergillus fumigatus, Candida albicans, Curvularia lunata, Fusarium keratoplasticum, Fusarium solani, Paecilomyces variotii, and Pseudallescheria boydii) were isolated from patients with confirmed infectious keratitis. Experiments were performed in triplicate with suspensions of each fungus exposed to different PDAT parameters including a control, green light exposure of 5.4 J/cm2, 2.7 J/cm2 (continuous and pulsed), and 1.8 J/cm2 and rose bengal concentrations of 0.1%, 0.05%, and 0.01%. Plates were photographed 72 h after experimentation, and analysis was performed to assess fungal growth inhibition. PDAT using 5.4 J/cm2 of irradiation and 0.1% rose bengal completely inhibited growth of five of the seven fungal species. Candida albicans and Fusarium keratoplasticum were the most susceptible organisms, with growth inhibited with the lowest fluence and minimum rose bengal concentration. Fusarium solani, Pseudallescheria boydii, and Paecilomyces variotii were inhibited by lower light exposures and photosensitizer concentrations. Aspergillus fumigatus and Curvularia lunata were not inhibited by any PDAT parameters tested. Continuous and pulsed irradiation using 2.7 J/cm2 produced similar results. Rose bengal PDAT successfully inhibits the in vitro growth of five fungi known to cause infectious keratitis. Differences in growth inhibition of the various fungi to multiple PDAT parameters suggest that susceptibilities to PDAT are unique among fungal species. These findings support modifying PDAT parameters based on the infectious etiology.

Brief incubation of corneal grafts in activated platelet rich plasma enhances corneal endothelial cell survival and regeneration.

Corneal transplantation is the most frequent organ transplantation worldwide. Unfortunately, corneal graft failure is common and endothelial decompensation is considered the major cause. Corneal endothelial cells (CECs) lack the capacity to reproduce, and perioperative and postoperative endothelial cell loss remains a significant challenge associated with corneal graft viability. Therefore, strategies to preserve CEC density are critical to extend graft survival. Activated platelet rich plasma (aPRP), a product extracted from autologous blood, has both antioxidant and regenerative properties. aPRP eye drops have shown effectiveness in the treatment of corneal pathologies such as ulcers, dry eye, and burns. Our purpose is to determine the protective and regenerative effect of aPRP on corneal grafts by evaluating aPRP's effect on the survival and proliferation of human CECs. Human corneal grafts were incubated in aPRP for 15 min to assess the activation of the CEC pAkt survival pathway as measured by ELISA. Evaluation of the protective effect of aPRP was made using an apoptotic model, which simulated oxidative stress conditions. Expression of apoptotic markers was measured using ELISA and endothelial cell viability was determined by optical microscopy. The CEC proliferation rate was measured in vitro with Ki-67 staining. Corneal graft gross structure was evaluated by Hematoxylin & Eosin and Masson trichrome staining. Our results indicate that a short incubation of human corneal grafts in aPRP protects CECs from apoptosis by upregulating the pAkt survival pathway and promoting CEC proliferation. Additionally, aPRP incubation does not induce histological changes in the grafts. A brief pre-treatment of human corneal grafts in aPRP may be beneficial for transplant longevity, as it protects CECs from apoptosis by upregulating intracellular survival pathways and promoting proliferation. In addition, this approach appears to be safe and has the potential to improve surgical outcomes following corneal transplantation.

Role of corneal biopsy in the management of infectious keratitis.

PURPOSE OF REVIEW: The aim of this study was to review the existing literature and investigate the role of microbiologic culture and histopathologic examination of corneal biopsies in the management of infectious keratitis. RECENT FINDINGS: Corneal biopsy continues to be a significantly useful tool in the diagnosis and tailored management of infectious keratitis. Several techniques can be employed for tissue collection, handling and processing to optimize diagnostic yield and maximize safety, including emerging femtosecond laser-assisted biopsy. SUMMARY: Corneal opacities represent a significant cause of global blindness, and infectious keratitis is the most common cause. Organism identification in progressive infectious keratitis is essential for proper management. However, microbiological culture alone has a high rate of false-negative results. Records from the Bascom Palmer Eye Institute were retrospectively searched for patients between 1 January 2015, and 31 December 2019, who underwent corneal biopsy, therapeutic keratoplasty or endothelial graft removal for infectious keratitis and had specimens bisected and submitted for evaluation with both microbiologic culture and histopathologic examination. Detection of bacteria, fungus and mycobacteria was not statistically different between culture and histopathology. Microbiology and histopathology are complementary methods for the identification of causative microorganisms in corneal specimens with presumed infectious keratitis.

Rose bengal photodynamic antimicrobial therapy to inhibit Pseudomonas aeruginosa keratitis isolates.

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

Interfacial Behavior of Fumonisin B1 Toxin and Its Degradation on the Membrane.

Fumonisin B1 (FB1), the most abundant component of the fumonisin family, is highly responsible for fungal infections. In this paper, our main aim is to study the surface chemistry and spectroscopic properties of the FB1 molecule and observe the impact of green LED light on the FB1 Langmuir monolayer. From the surface chemistry and spectroscopic studies, we found that the FB1 molecule forms a self-assembled Langmuir monolayer which is sufficient to mimic its interaction with the corneal tissues. The irradiation of green LED light on the FB1 Langmuir monolayer showed the degradation of the FB1 when compared to that in the absence of light. This observation reveals that FB1 molecules lose their tendency to stay as a Langmuir monolayer. The degradation observed on the interface was compared with the bulk phase of FB1. The bulk phase observation also indicated the degradation tendency which reinforced the observed interfacial property of FB1.

0.01% Hypochlorous Acid as an Alternative Skin Antiseptic: An In Vitro Comparison.

OBJECTIVE: Compare the in vitro efficacy of hypochlorous acid 0.01% (HA), povidone iodine 5% (PI), chlorhexidine gluconate 4% (CHG), and isopropyl alcohol 70% (IPA) against common skin microorganisms. MATERIALS AND METHODS: Time-kill studies were conducted against methicillin-susceptible Staphylococcus aureus (MSSA) and Staphylococcus epidermidis (MSSE), methicillin-resistant S. aureus (MRSA) and S. epidermidis (MRSE), Candida albicans, Corynebacterium species (striatum and amycolatum), Propionibacterium acnes, Pseudomonas aeruginosa, Streptococcus pyogenes, Staphylococcus capitis, and Staphylococcus xylosus. RESULTS: Methicillin-resistant S. aureus: Bactericidal effect was immediate for HA and IPA. For PI and CHG, the effect occurred at 1 and 10 minutes, respectively. Methicillin-resistant S. epidermidis: Hypochlorous acid, IPA, and PI had immediate bactericidal effects, whereas CHG required 1 minute. Methicillin-susceptible Staphylococcus aureus: All agents had bactericidal effects at 1 minute. C. species, S. pyogenes, P. aeruginosa, and P. acnes: All antiseptics demonstrated immediate bactericidal effects. Methicillin-susceptible Staphylococcus epidermidis and S. capitis: Hypochlorous acid and IPA had immediate effect, whereas PI and CHG required 1 minute. C. albicans: Hypochlorous acid, IPA, and PI were immediately bactericidal, whereas CHG required 1 minute. S. xylosus: Hypochlorous acid and CHG were immediately bactericidal, whereas IPA and PI required 1 and 2 minutes, respectively. CONCLUSION: In vitro studies of HA 0.01% were observed to have equal or more efficacious antiseptic properties compared with IPA, CHG, and PI. Future studies will be needed to investigate its role in periocular use.

Microbiology and Biofilm Trends of Silicone Lacrimal Implants: Comparing Infected Versus Routinely Removed Stents.

PURPOSE: To investigate the pathogens and biofilms responsible for clinically significant infection of silicone stents implanted within the lacrimal system. METHODS: Retrospective review of culture results and patient demographics for all silicone lacrimal stents removed early for clinically significant infection and sent to the Bascom Palmer Microbiology Laboratory through the end of year 2010. As a control, routinely removed, clinically noninfected stents from the same institution were prospectively sent for culture over a 6-month period. Four clinically infected and 6 clinically noninfected stents showing mucus within the lumen at removal were sent for scanning electron microscopy. Images were randomized and graded by a microbiologist for the presence of organisms, matrix deposits, organisms within matrix, and overall impression of significant biofilm formation. RESULTS: Nineteen stents were included in the study; 100% of clinically infected (n = 10) and noninfected (n = 9) stents were culture positive. Culture positivity for nontuberculous mycobacterium was found in 90% of infected stents and none of the noninfected stents (p < 0.001). Of infected stents, 50% grew Gram-positive organisms compared with 89% of noninfected stents (p = 0.07). Fifty percent of infected versus 67% of noninfected stents were culture positive for Gram-negative organisms (p = 0.46). Electron microscopy of stents revealed organisms consistent with culture results (size, shape) in planktonic and biofilm form. Masked observer image grading revealed a statistically significant higher amount of organism and biofilm on infected versus noninfected specimen. CONCLUSION: Nontuberculous mycobacteria comprise the primary pathogens responsible for clinically significant infection of silicone stents in the lacrimal system in South Florida. Robust biofilm production by this organism likely plays a role in pathogenesis. Further research into biofilm-related lacrimal implant infection may aid in the development of useful prevention and treatment strategies.

ENDOPHTHALMITIS CAUSED BY PSEUDOMONAS AERUGINOSA: Clinical Features, Antibiotic Susceptibilities, and Treatment Outcomes.

PURPOSE: To report the clinical features, antibiotic susceptibilities, and visual outcomes associated with endophthalmitis caused by Pseudomonas aeruginosa. METHODS: A consecutive case series. Microbiology database records were retrospectively reviewed for all patients with endophthalmitis caused by P. aeruginosa from January 1, 2002, to December 31, 2012, at a large university referral center. The corresponding clinical records were then reviewed to evaluate the endophthalmitis clinical features and treatment outcomes. RESULTS: In the 12 patients identified, clinical settings included postcataract surgery (n = 4), postpenetrating keratoplasty (n = 3), endogenous source (n = 2), post-pars plana vitrectomy (n = 1), trabeculectomy bleb-associated setting (n = 1), and glaucoma drainage implant-associated setting (n = 1). All patients presented with hypopyon. Presenting visual acuity was hand motions or worse in all cases. All isolates were susceptible to ceftazidime and levofloxacin. When comparing isolates in this study with isolates from a previous study (1987 to 2001), the minimal inhibitory concentration required to inhibit 90% of isolates (MIC 90, in micrograms per milliliter) remained the same for ceftazidime (8), ciprofloxacin (0.5), imipenem (4), tobramycin (0.5), and amikacin (4). Initial treatment strategies were vitreous tap and injection (n = 9) and pars plana vitrectomy with intravitreal antibiotics (n = 3). Final visual acuity was light perception or worse in 11 of the 12 patients (92%). Five patients underwent enucleation (42%). CONCLUSION: All isolates were susceptible to ceftazidime and levofloxacin, and all MIC 90s for isolates in the current period compared with isolates from 1987 to 2001 remained identical. Despite early and appropriate treatment, outcomes were generally poor with a high rate of enucleation.

ENDOPHTHALMITIS CAUSED BY SERRATIA MARCESCENS: Clinical Features, Antibiotic Susceptibilities, and Treatment Outcomes.

PURPOSE: To report the clinical features, antibiotic sensitivities, and visual outcomes associated with endophthalmitis caused by Serratia marcescens. METHODS: A consecutive case series of patients with vitreous culture-positive endophthalmitis caused by S. marcescens from July 1, 1993, to June 30, 2012, at a large university referral center. Findings from this study were compared with those of a previous study (January 1980-June 1993) from our institution. RESULTS: Of the 10 study patients who were identified, clinical settings included trabeculectomy bleb-associated (n = 3), post-cataract surgery (n = 2), post-penetrating keratoplasty (n = 2), post-scleral buckle (n = 1), glaucoma drainage implant-associated (n = 1), and post-keratoprosthesis (n = 1). Clinical features included pain (n = 10) and hypopyon (n = 5). Presenting visual acuity was hand motions or worse in seven cases. All isolates were sensitive to gentamicin, ceftazidime, imipenem, and levofloxacin. The MIC 90s of isolates for antibiotics tested in the current period compared with isolates from January 1980 to June 1993 were unchanged. All isolates were resistant to vancomycin. Initial treatment strategies were vitreous tap and intravitreal antibiotic injection (n = 8), pars plana vitrectomy with intravitreal antibiotic injection (n = 1), and evisceration (n = 1). When repeat vitreous fluid was obtained, persistent positive cultures were present in 1 (10%) of 10 patients in this study, compared with 5 (50%) of 10 patients in the previous study. Final visual acuity was no light perception in 6 of 10 patients (60%). CONCLUSION: Outcomes were generally poor with a high rate of complete visual loss in the affected eye.

Cysticidal activity of antifungals against different genotypes of Acanthamoeba.

Antifungal drugs have been proposed as a novel treatment for Acanthamoeba keratitis. The cysticidal activity of several antifungal compounds was tested against different genotypes of culture collection and clinical isolates of Acanthamoeba. Only voriconazole and posaconazole were found to be cysticidal, with no differences in activity observed between clinical and culture collection isolates.

Endophthalmitis caused by Klebsiella species.

PURPOSE: To report the clinical presentation, antibiotic sensitivities, treatment strategies, and visual outcomes associated with endophthalmitis caused by Klebsiella species. METHODS: A noncomparative consecutive case series. Microbiology database records were retrospectively reviewed for all patients with endophthalmitis caused by Klebsiella species from 1990 to 2012 at a large university referral center. The corresponding clinical records were then reviewed to evaluate the endophthalmitis clinical features and treatment outcomes. RESULTS: Seven patients were identified. Clinical settings included endogenous (n = 3), posttraumatic (n = 2), trabeculectomy bleb-associated (n = 1), and postpenetrating keratoplasty (n = 1). Five patients presented with hypopyon. Presenting visual acuity ranged from 20/60 to light perception in nonendogenous cases and 1/200 to light perception in endogenous cases. Klebsiella was sensitive to aminoglycosides, third-generation cephalosporins, and second- and third-generation fluoroquinolones in all cases. Initial treatment strategies were vitreous tap and injection (n = 4), pars plana vitrectomy with intravitreal antibiotics (n = 2), and anterior chamber tap and injection (n = 1). All three endogenous cases later underwent enucleation or evisceration. In nonendogenous cases, the final visual acuity was 20/70 or better in all 4 patients. CONCLUSION: Endophthalmitis caused by Klebsiella species is associated with poor visual outcomes. Endogenous cases had high rates of enucleation or evisceration.

Endophthalmitis caused by Achromobacter xylosoxidans after cataract surgery.

PURPOSE: To report Achromobacter xylosoxidans as a cause of both acute-onset and delayed-onset postoperative endophthalmitis after cataract surgery. METHODS: A noncomparative consecutive case series of patients with culture-proven A. xylosoxidans endophthalmitis between 1970 and 2012. Cataract surgery and intraocular lens placement were performed in all patients before endophthalmitis. Positive cultures were obtained from the vitreous, capsular bag, and/or the removed intraocular lens. RESULTS: The clinical diagnosis was confirmed in four patients with positive cultures. Two patients with endophthalmitis had a preliminary culture report of Pseudomonas species. In addition to receiving intravitreal antibiotics, all patients underwent capsulectomy and intraocular lens removal at the time of pars plana vitrectomy. Visual acuity at last follow-up was 20/40 or better in 2 (50%) of the 4 patients, but the remaining 2 patients were 20/200 or worse. CONCLUSION: A. xylosoxidans may be a cause of acute, recurrent, and delayed-onset postoperative endophthalmitis after cataract surgery. Complete capsulectomy and intraocular lens removal can be considered in recurrent and recalcitrant patients.

Phylogenetic and Recombination Analysis of Clinical Vitreous Humor-Derived Adenovirus Isolates Reveals Discordance Between Serotype and Phylogeny.

Purpose: To sequence, identify, and perform phylogenetic and recombination analysis on three clinical adenovirus samples taken from the vitreous humor at the Bascom Palmer Eye Institute. Methods: The PacBio Sequel II was used to sequence the genomes of the three clinical adenovirus isolates. To identify the isolates, a full genome-based multiple sequence alignment (MSA) of 722 mastadenoviruses was generated using multiple alignment using fast Fourier transform (MAFFT). MAFFT was also used to generate genome-based human adenovirus B (HAdV-B) MSAs, as well as HAdV-B fiber, hexon, and penton protein-based MSAs. To examine recombination within HAdV-B, RF-Net 2 and Bootscan software programs were used. Results: In the course of classifying three new atypical ocular adenovirus samples, taken from the vitreous humor, we found that all three isolates were HAdV-B species. The three Bascom Palmer HAdV-B genomes were then combined with over 300 HAdV-B genome sequences, including nine ocular HAdV-B genome sequences. Attempts to categorize the penton, hexon, and fiber serotypes using phylogeny of the three Bascom Palmer samples were inconclusive due to incongruence between serotype and phylogeny in the dataset. Recombination analysis using a subset of HAdV-B strains to generate a hybridization network detected recombination between nonhuman primate and human-derived strains, recombination between one HAdV-B strain and the HAdV-E outgroup, and limited recombination between the B1 and B2 clades. Conclusions: The discordance between serotype and phylogeny detected in this study suggests that the current classification system does not accurately describe the natural history and phylogenetic relationships among adenoviruses.

Role of Topical 5-Fluorouracil in Demodex -Associated Blepharitis.

PURPOSE: The aim of this study was to report clinical observations suggesting the efficacy of topical 1% 5-fluorouracil (5-FU) in treating Demodex -associated blepharitis. METHODS: An observational retrospective review of 13 eyes from 13 individuals with conjunctival neoplastic lesions and concomitant Demodex lash infestation that received topical 1% 5-FU eye drops. Patients underwent slit-lamp examination at each follow-up visit. Clinical photographs of the lash line were obtained after treatment initiation. In a subset of patients, lashes were epilated bilaterally and microscopically analyzed for presence of Demodex mites before and after treatment initiation. RESULTS: The mean age of the population was 68 ± 14 years (range: 30-84 years) and 92% were male. In all 13 patients, a marked reduction in cylindrical dandruff was noted in the treated eye by slit-lamp examination after 2 cycles of 5-FU. There was complete resolution of cylindrical dandruff in 10 of 13 treated eyes compared with 0 resolution of cylindrical dandruff in untreated eyes ( P = 0.0001). In the 6 patients who received epilation, the lashes from the treated eye showed no Demodex , whereas lashes from the fellow untreated eye revealed persistent Demodex . CONCLUSIONS: Topical 1% 5-FU shows efficacy in treating Demodex -associated blepharitis. Further studies are indicated to reproduce our findings and evaluate the potential use of 5-FU as a treatment ingredient.

Enhancing Rose Bengal penetration in ex vivo human corneas using iontophoresis.

Aim: Rose Bengal photodynamic antimicrobial therapy (RB-PDAT) has poor corneal penetration, limiting its efficacy against acanthamoeba keratitis (AK). Iontophoresis enhances corneal permeation of charged molecules, piquing interest in its effects on RB in ex vivo human corneas. Methods: Five donor whole globes each underwent iontophoresis with RB, soaking in RB, or were soaked in normal saline (controls). RB penetration and corneal thickness was assessed using confocal microscopy. Results: Iontophoresis increased RB penetration compared with soaking (177 ± 9.5 µm vs. 100 ± 5.7 µm, p < 0.001), with no significant differences in corneal thickness between groups (460 ± 87 µm vs. 407 ± 69 µm, p = 0.432). Conclusion: Iontophoresis significantly improves RB penetration and its use in PDAT could offer a novel therapy for acanthamoeba keratitis. Further studies are needed to validate clinical efficacy.

The study aimed to improve a new treatment for eye infections known as photodynamic antimicrobial therapy. It investigated whether the use of electricity through a technique called iontophoresis could help a chemical called Rose Bengal go deeper into the eye in order to target more severe infections. The iontophoresis machine was custom built, with patient-contacting components 3D printed. The experiments were performed using donated human eye tissue and found that iontophoresis significantly improved the penetration depth of Rose Bengal as compared with the current technique of only soaking the eye in Rose Bengal.

Clinical Features and Treatment Outcomes of Carbapenem-Resistant Pseudomonas aeruginosa Keratitis.

Importance: Evaluation of the microbiological diagnostic profile of multidrug-resistant Pseudomonas aeruginosa keratitis and potential management with rose bengal-photodynamic antimicrobial therapy (RB-PDAT) is important. Objective: To document the disease progression of carbapenemase-resistant P aeruginosa keratitis after an artificial tear contamination outbreak. Design, Setting, and Participants: This retrospective observation case series included 9 patients 40 years or older who presented at Bascom Palmer Eye Institute and had positive test results for multidrug-resistant P aeruginosa keratitis between January 1, 2022, and October 31, 2023. Main Outcomes and Measures: Evaluation of type III secretion phenotype, carbapenemase-resistance genes blaGES and blaVIM susceptibility to antibiotics, and in vitro and in vivo outcomes of RB-PDAT against multidrug-resistant P aeruginosa keratitis. Results: Among the 9 patients included in the analysis (5 women and 4 men; mean [SD] age, 73.4 [14.0] years), all samples tested positive for exoU and carbapenemase-resistant blaVIM and blaGES genes. Additionally, isolates were resistant to carbapenems as indicated by minimum inhibitory concentration testing. In vitro efficacy of RB-PDAT indicated its potential application for treating recalcitrant cases. These cases highlight the rapid progression and challenging management of multidrug-resistant P aeruginosa. Two patients were treated with RB-PDAT as an adjuvant to antibiotic therapy and had improved visual outcomes. Conclusions and Relevance: This case series highlights the concerning progression in resistance and virulence of P aeruginosa and emphasizes the need to explore alternative therapies like RB-PDAT that have broad coverage and no known antibiotic resistance. The findings support further investigation into the potential effects of RB-PDAT for other multidrug-resistant microbes.

Emerging 8-methoxyfluoroquinolone resistance among methicillin-susceptible Staphylococcus epidermidis isolates recovered from patients with endophthalmitis.

Fluoroquinolones remain the most commonly used antimicrobials for the prevention and management of bacterial endophthalmitis. Coagulase-negative staphylococci are the most frequently recovered pathogens. Increasing resistance among this group has paralleled the presence of methicillin resistance. From 2005 to 2010, we recovered 38 methicillin-susceptible Staphylococcus epidermidis (MSSE) isolates from endophthalmitis patients at our institute, including 15 (39.5%) isolates resistant to gatifloxacin and moxifloxacin, members of the C-8-methoxyfluoroquinolones family. Mutations in the quinolone resistance-determining regions (QRDR) of gyrA and parC were determined and correlated with fluoroquinolone MICs based on Etests of these 15 MSSE isolates. High-level resistance (MIC, >32 µg/ml) to gatifloxacin and moxifloxacin was documented for 46.7% of the MSSE isolates, and low-level resistance (MIC, 2 to 4 µg/ml) was determined for 53.3%. The MICs for ciprofloxacin, levofloxacin, and ofloxacin were >32 µg/ml for all isolates. The amino acid substitution Ser84Phe in gyrA was found among all isolates. A second mutation in gyrA (Glu88Lys) resulted in high-level resistance to moxifloxacin and gatifloxacin. Almost all (92.8%) isolates presented double point mutations in the parC gene at codons 80 and 84 with different combinations. Eighty-seven percent of the patients had prior exposure to topical 8-methoxyfluoroquinolones. Prior exposure to the 8-methoxyfluoroquinolones may contribute to the selection of MSSE strains containing multiple mutations in the QRDRs of gyrA and parC that results in low- and high-level resistance to these agents.

A novel rat contact lens model for Fusarium keratitis.

PURPOSE: The aim of this study was to develop and characterize a new contact lens-associated fungal keratitis rat model and to assess the ability of non-invasive spectral-domain optical coherence tomography (SD-OCT) to detect pathological changes in vivo in fungal keratitis. METHODS: We used SD-OCT to image and measure the cornea of Sprague Dawley rats. Fusarium infection was initiated in the rat eye by fitting Fusarium solani-soaked contact lenses on the experimental eye, while the control animals received contact lenses soaked in sterile saline. The fungal infection was monitored with periodic slit-lamp examination and in vivo SD-OCT imaging of the rat eye, and confirmed by histology, counting of viable fungi in the infected rat cornea, and PCR with specific primers for Fusarium sp. RESULTS: We imaged and measured the rat cornea with SD-OCT. Custom-made contact lenses were developed based on the OCT measurements. Incubation of contact lenses in a F. solani suspension resulted in biofilm formation. We induced contact lens-associated Fusarium keratitis by fitting the rat eyes for 4 h with the Fusarium-contaminated contact lenses. The SD-OCT images of the cornea correlated well with the slit-lamp and histopathological results and clearly defined clinical signs of infection, namely, increased corneal thickening, loss of epithelial continuity, hyper-reflective areas representing infiltrates, and endothelial plaques characteristic of fungal infection. Moreover, in three cases, SD-OCT detected the infection without any clear findings on slit-lamp examination. Infection was confirmed with histological fungal staining, PCR, and microbiological culture positivity. CONCLUSIONS: We developed a highly reproducible rat contact lens model and successfully induced contact lens-associated Fusarium keratitis in this model. The clinical presentation of contact lens-associated Fusarium keratitis in the rat model is similar to the human condition. SD-OCT is a valuable tool that non-invasively revealed characteristic signs of the fungal infection and could provide sensitive, objective monitoring in fungal keratitis.