Molecular characterization of fungal endophthalmitis and keratitis caused by yeasts.

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

Candida species are the most common pathogen responsible for ocular infections in the temperature regions of the world. Here, we sequenced and molecularly characterized the Candida species seen in patients who present to our hospital with infection to understand the species' distribution over time.

Proteomic profiling of aspergillus flavus endophthalmitis derived extracellular vesicles in an in-vivo murine model.

Extracellular Vesicles (EVs) play pivotal roles in cell-to-cell communication, and are involved in potential pathological and physiological cellular processes. The aim of this study was to understand the proteomic cargo of these vesicles, in a murine model of Aspergillus flavus (AF) endophthalmitis. EVs were isolated from A. flavus infected C57BL/6 mice eyes by differential ultracentrifugation at 24 h post infection (p.i) and isolated EVs were characterized by Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), Exocet assay, and western blot. Proteomic profiling of EVs was then evaluated by mass spectrometry (LC-MS/MS) and compared it with control uninfected mice. The average size of the EVs were 180-280 nm by DLS and the number of EVs increased to 1.55 × 1010 in infected mice in comparison to EVs from uninfected eye (1.24 × 109). Western blot was positive for CD9, CD63, and CD81 confirming the presence of EVs. LC-MS/MS analysis, identified 81 differentially expressed proteins, of these 22 were up-regulated and 59 were down-regulated. Gene Ontology (GO) analysis revealed enrichment of lipid metabolism, protein complex binding, and transferase activity, and the proteins associated were Aquaporin-5, CD177 antigen, Solute carrier family-25, and Calcium/calmodulin-dependent protein kinase. Additionally, KEGG pathway analysis indicated that glucagon signalling, metabolic, and PPAR signalling pathway were significantly associated with EVs from A. flavus infected mice eyes. The protein cargo in EVs from A. flavus endophthalmitis provides new insights into the pathogenesis of fungal endophthalmitis and validation of these proteins can serve as diagnostic and/or prognostic biomarkers for patients with a clinical suspicion of fungal endophthalmitis. LAY SUMMARY: EVs play an important role in cell communication. In our study proteomic profiling of EVs isolated from A. flavus infected mice provided new insights into the understanding of the pathobiology of A. flavus endophthalmitis and validation of these proteins can serve as biomarkers.

Ophthalmic findings in a septic calf with the concurrent exhibition of meningitis and endophthalmitis.

The aim of this study was to evaluate the impacts of ophthalmic findings obtained from both macroscopic examination and ocular ultrasonography when diagnosing bovine endophthalmitis. A newborn crossbreed (Japanese black and Holstein breeds) calf was suspected of visual impairment and central nervous system (CNS) symptoms, such as decreased activity and weak drinking performance. This calf was found to display macroscopic signs, such as clouded lens, convergent strabismus, and horizontal nystagmus, in both eyes. On ocular ultrasonography of both eyes, a V-shaped, thickened, hyperechoic structure was present in the anechoic vitreous humors, indicating retinal detachment. The animal died 4 days after the examination. Sepsis was evident in this case, as Escherichia coli was isolated from multiple organs. The autopsy and histological examination revealed meningitis, encephalitis, and secondary hydrocephalus in the CNS, and endophthalmitis and retinal detachment in both eyes. In this case, the ophthalmic findings did not provide definitive evidence for a diagnosis of endophthalmitis. However, this study indicated that retinal detachment might be an ultrasonographic finding that is suggestive of bovine endophthalmitis.

Supposed endogenous endophthalmitis caused by Serratia marcescens in a cat.

An 8-year-old male neutered domestic shorthair cat was presented for evaluation of acute respiratory distress. Respiratory auscultation revealed a diffuse and symmetric increase in bronchovesicular sounds. Thoracic radiographs showed a diffuse unstructured interstitial pulmonary pattern with multifocal alveolar foci. Despite an aggressive treatment with supportive care, including oxygenotherapy and systemic antibiotics, progressive respiratory distress increased. Three days after the presentation, acute anterior uveitis was noticed on left eye. Ophthalmic examination and ocular ultrasonography revealed unilateral panuveitis with ocular hypertension. The right eye examination was unremarkable. Cytological examination of aqueous humor revealed a suppurative inflammation. Serratia marcescens was identified from aqueous humor culture. Primary pulmonary infection was suspected but was not confirmed as owners declined bronchoalveolar lavage. Active uveitis resolved and cat's pulmonary status improved after appropriate systemic antibacterial therapy. Vision loss was permanent due to secondary mature cataract. To the best of authors' knowledge, this is the first report of endogenous bacterial endophthalmitis secondary to S. marcescens infection in a cat.

In vitro synergistic effect of baicalin with azithromycin against Staphylococcus saprophyticus isolated from francolins with ophthalmia.

Francolins ophthalmia is often caused by resistant conditional pathogenic bacteria. Conditional pathogenic Staphylococcus saprophyticus is a potential reservoir of macrolides antibiotics resistance gene. Baicalin has been reported as a potential agent to synergistically inhibit the replication of Staphylococcus. The objective of this study was to isolate the pathogen of the francolins ophthalmia, identify the antibiotic resistance profile of isolated S. saprophyticus, and investigate the effect of baicalin combined with azithromycin (Azm) against azithromycin resistant S. saprophyticus (ARSS). The ARSS was isolated and identified from francolins suffered from ophthalmia by phenotypic and molecular biology methods. The antibiotic resistance profile was identified by Kirby-Bauer method. Then the minimal inhibitory concentration (MIC) of Azm in absence and presence of a sub-inhibitory concentration baicalin/verapamil was determined to assess the effect that baicalin combined with Azm against ARSS. ARSS was isolated and identified from francolins experienced ophthalmia. The isolated ARSS was resistant to 11 among the 13 antibiotics that were tested. The synergistic effect of baicalin and Azm was noticed with a reduction rate varied from 2 to 128-fold. It appears from this study that S. saprophyticus can cause francolins ophthalmia and baicalin may be used as a natural agent resistance inhibitor for ARSS.

Ophthalmic complications following ocular penetration during routine dentistry in 13 cats.

CASE HISTORY Thirteen cats developed ophthalmic complications following dental procedures in Australia and New Zealand between December 2014 and February 2018. All cats had at least one maxillary tooth extracted and some received a transoral maxillary nerve block. CLINICAL FINDINGS Ocular signs were identified at a median of 1.5 (min 0, max 14) days following elective dental procedures and included fibrin in the anterior chamber, aqueous flare, vision loss and miosis. Response to medical management was poor overall, with 7/13 (54%) cats undergoing subsequent enucleation and one cat was subjected to euthanasia shortly after the dental procedure due to ocular disease. The remaining five cats were managed medically. Of these, four exhibited signs of persistent inflammation at the last ophthalmic assessment, and one was subsequently subjected to euthanasia due to reasons unrelated to ocular health. Active inflammation resolved in one cat, however the lesions caused by previous inflammation persisted. PATHOLOGICAL FINDINGS Assessment of six enucleated globes showed a variety of pathological changes, with marked fibrinous exudation and suppurative inflammation as predominant features. A scleral penetration site was identified in three globes. Four globes had lens capsule rupture and phacoclastic uveitis. DIAGNOSIS Endophthalmitis following iatrogenic globe penetration during routine dental procedures. CLINICAL RELEVANCE This case series demonstrates that globe penetration during dental procedures carries a poor prognosis for the eye. Clinicians should be aware of the risks of ocular trauma during dental procedures in cats and great care should be taken to avoid ocular penetration, particularly during tooth extractions. Transoral maxillary nerve blocks should be avoided or used with extreme caution in cats.

Incidence and characteristics of acute-onset postoperative bacterial and sterile endophthalmitis in dogs following elective phacoemulsification: 1,447 cases (1995-2015).

OBJECTIVE To characterize and determine the incidence of acute-onset (ie, developing ≤ 6 weeks after surgery) postoperative infectious and sterile endophthalmitis in dogs following elective cataract surgery. DESIGN Retrospective case series. ANIMALS 2,630 eyes of 1,447 dogs that underwent elective unilateral or bilateral cataract surgery by phacoemulsification at Cornell University from 1995 through 2015. PROCEDURES Medical records were reviewed to collect and summarize data regarding dog signalment, clinical findings, diagnostic test results, surgery characteristics, eye or eyes affected, concurrent major systemic diseases, treatments, and clinical outcome. RESULTS Infectious endophthalmitis developed in 4 eyes of 4 dogs during the follow-up period, representing 0.15% of eyes and 0.28% of dogs that underwent surgery. Unilateral sterile endophthalmitis developed in 3 (0.11%) eyes of 3 (0.21%) dogs. All cases of infectious endophthalmitis were unilateral and in pseudophakic eyes and followed bilateral cataract surgeries. Clinical signs consistent with infectious endophthalmitis developed a median of 18 days after surgery and included marked and progressive hypopyon; Staphylococcus or Streptococcus spp were recovered from aqueous and vitreous humor samples. All eyes with infectious endophthalmitis responded poorly to medical treatment and were enucleated. In 2 eyes with infectious endophthalmitis, corneal incision nonunion with epithelial downgrowth was identified histologically and postulated as the route of bacterial entry into the globe. CONCLUSIONS AND CLINICAL RELEVANCE Bacterial endophthalmitis following elective phacoemulsification was uncommon in the dogs of this study. Introduction of bacteria into the eye may occur during surgery or in the postoperative period from corneal incisions that fail to heal normally.

Molecular characterization and potential sources of aqueous humor bacterial contamination during phacoemulsification with intraocular lens implantation in dogs.

Bacterial contamination of the anterior chamber during cataract surgery is one of the main responsible for endophthalmitis postoperative. Phacoemulsification is a less invasive technique for cataract treatment, although it does not exclude the possibility of contamination. In this study, bacterial contaminants of aqueous humor collected pre- and post-phacoemulsification with intraocular lens implantation (IOL) of twenty dogs were identified. As the conjunctival microbiota constitute a significant source of anterior chamber contamination, bacterial isolates from aqueous humor were genetically compared with those present in the conjunctival surface of the patients. Three dogs presented bacterial growth in both aqueous humor and conjunctival surface samples. Bacterial isolates from these samples were grouped according to their genetic profiles by repetitive-element PCR (rep-PCR) and their representatives were identified by 16S rRNA sequencing. Isolates from conjunctival surface were identified as Enterobacter spp., Staphylococcus spp. and S. aureus; and from aqueous humor samples as Enterobacter spp., Pantoea spp., Streptococcus spp. and Staphylococcus spp., respectively in decreasing order of prevalence. According to the rep-PCR analysis, 16.6% of Enterobacter spp. isolates from conjunctival surface were genetically similar to those from aqueous humor. The rest of isolates encountered in aqueous humor were genetically distinct from those of conjunctival surface. The significant genetic diversity of bacterial isolates found in the aqueous humor samples after surgery denoted the possibility of anterior chamber contamination during phacoemulsification by bacteria not only from conjunctival surface but also from different sources related to surgical environment.

Endogenous mycotic endophthalmitis in a dog with candiduria and Evans syndrome.

This report describes the clinical presentation, diagnosis, histologic lesions, and outcome of endogenous mycotic endophthalmitis secondary to candiduria in a three-year-old female spayed Dachshund. The dog was being treated for Evans syndrome for one month prior to being diagnosed with candiduria and fibrinous uveitis OS. The left eye was enucleated due to secondary glaucoma, and the fungal urinary tract infection was treated successfully. Uveitis developed in the contralateral eye with relapse of the urinary tract infection in the following weeks. The right eye was medically managed until secondary glaucoma developed and was subsequently enucleated. Histopathology of both eyes showed evidence of endophthalmitis with intralesional fungal organisms, consistent with Candida spp. Ocular candidiasis is rare in dogs. To the authors' knowledge, this is the first report of endogenous mycotic endophthalmitis with concurrent candiduria in a dog.

Endogenous endophthalmitis caused by Enterococcus faecalis in a cat.

A three-year-old male neutered domestic shorthair cat was presented for loss of vision associated with hyperthermia, lethargy and anorexia. Ophthalmic examination revealed a bilateral panuveitis. Cytological examination of aqueous and vitreous humours was performed and revealed a suppurative inflammation associated with numerous cocci. Enterococcus faecalis was identified by bacterial culture from aqueous and vitreous humour. No primary infection site was identified. Active uveitis resolved after systemic antibiotic therapy, but the vision loss was permanent. To the authors' knowledge, this is the first reported case of endogenous bacterial endophthalmitis secondary to E. faecalis infection in a cat.

Acute postoperative Staphylococcus schleiferi endophthalmitis following uncomplicated cataract surgery: first report in the literature.

INTRODUCTION: We report a rare case of acute postoperative Staphylococcus schleiferi endophthalmitis following an uneventful cataract extraction.
 METHODS: An 83-year-old woman underwent uneventful phacoemulsification without receiving the usual intracameral cefuroxime solution due to cephalosporin intolerance. Two days postoperatively, she presented with acute ocular pain and blurred vision in the operated eye. Ophthalmic examination revealed signs of acute keratitis and endophthalmitis. Corneal scrapes and vitreous taps were sent for cultivation and analysis. The patient received intravitreal antibiotics at the same time.
 RESULTS: Cultivation grew S schleiferi, a pathogen commonly found in dogs. Following microbiological report, the patient received a repeated intravitreal injection of 1 mg/0.1 mL vancomycin combined with fortified topical vancomycin drops. One week later, the inflammation subsided completely while the corneal ulcer healed and visual acuity improved dramatically. Further examination revealed the existence of the same pathogen in a specimen obtained from the dog owned by the patient's family.
 CONCLUSIONS: This description of S schleiferi endophthalmitis highlights the need to provide alternative intracameral antibiotic solution in the operating room and avoid direct contact with dogs during the first postoperative period after intraocular surgery.

Actinomyces endogenous endophthalmitis in a cat following multiple dental extractions.

An 8-year-old, brachycephalic, mixed breed cat underwent full mouth tooth extractions for the treatment of tooth root abscessation. Subsequently, the cat developed anterior uveitis refractory to topical therapy that eventually necessitated enucleation. Actinomyces species were isolated from both the tooth root abscesses and the anterior chamber after enucleation. Histopathology of the enucleated eye revealed panophthalmitis with abundant intralesional bacteria morphologically consistent with Actinomyces. Between the time of tooth root extraction and enucleation (20 weeks), the cat was diagnosed with hyperthyroidism and treated with oral steroids for inflammatory bowel syndrome. We believe this report represents a rare case of endogenous endophthalmitis secondary to dental disease, possibly precipitated by concurrent immunosuppression.

Septic implantation syndrome in dogs and cats: a distinct pattern of endophthalmitis with lenticular abscess.

OBJECTIVE: To summarize the clinical and pathologic findings in a group of dogs and cats with progressive clinical ocular disease, which were diagnosed with suppurative endophthalmitis and lens capsule rupture. ANIMALS STUDIED: Twenty cats and forty-six dogs that underwent unilateral enucleation or evisceration for intractable uveitis and/or glaucoma. PROCEDURE: Biopsy submission requests and microscopic case material were evaluated for clinical and histological features, including history of ocular trauma, duration of ocular disease, pattern of inflammation, and the presence of intralenticular microorganisms. RESULTS: The median duration for cats and dogs was 6 and 5 weeks, respectively. A history of trauma was reported for four (20%) cats and 18 (39%) dogs. All confirmed cases of trauma-three in cats and 14 in dogs-were caused by a cat scratch. Microscopically, all cases had suppurative endophthalmitis centered on the lens, lens capsule rupture, cataract, and lenticular abscess. Infectious organisms were identified by Gram stain within the lens of 14 (70%) cats and 30 (65%) dogs. Gram-positive cocci were seen most commonly. Male cats were overrepresented as compared to females. There were no apparent gender, age or breed predilections in dogs. CONCLUSIONS: A unique pattern of slowly progressive or delayed-onset endophthalmitis with lens capsule rupture, lenticular abscess, and frequently intralenticular microorganisms is associated with traumatic penetration of the globe and lens capsule. The term Septic Implantation Syndrome (SIS) is favored in lieu of 'phacoclastic uveitis' to avoid confusion with phacolytic uveitis and to clearly implicate the role of intralenticular microorganisms in the pathogenesis.

Brucella canis endophthalmitis in 3 dogs: clinical features, diagnosis, and treatment.

OBJECTIVE: To describe historical, clinical and diagnostic features of dogs with Brucella canis endophthalmitis and the response to medical therapy. ANIMALS STUDIED: Three dogs with naturally acquired B. canis endophthalmitis. PROCEDURE: Dogs were treated symptomatically with topical ophthalmic anti-inflammatories and a novel antimicrobial protocol that included doxycycline, enrofloxacin, rifampin and streptomycin. RESULTS: All dogs presented with chronic or recurrent uveitis in the absence of overt systemic disease. Clinical ophthalmologic abnormalities were unilateral in each dog and included mild-to-moderate anterior uveitis, iris hyperpigmentation, marked vitreal infiltrates, and multifocal chorioretinitis. Dogs were diagnosed with canine brucellosis serologically and by blood culture (n = 2 dogs) or polymerase chain reaction of aqueous humor and blood (n = 1 dog). Active ocular inflammation resolved in all dogs during treatment, with preservation of vision in 2 dogs. Following treatment, B. canis could not be cultured from blood samples and serological values declined with seronegativity achieved in all dogs after a median of 96 weeks (range: 36-112 weeks) of therapy. CONCLUSIONS: Brucella canis infection should be included in the differential diagnosis for dogs with intraocular inflammation, regardless of previous history or neuter status. This is the first report of apparently successful medical therapy of canine brucellosis with ocular involvement.

Pathogenic phenotype and genotype of Pseudomonas aeruginosa isolates from spontaneous canine ocular infections.

PURPOSE: This study was designed to determine whether the ability to adversely affect corneal epithelial cell health is a factor common to Pseudomonas aeruginosa keratitis strains and to assess the prevalence of each pathogenic phenotype and genotype in a canine model of naturally-acquired P. aeruginosa ocular infection. METHODS: P. aeruginosa ocular isolates were collected by sampling 100 dogs without disease (six isolates collected) and by sampling dogs with conjunctivitis (two isolates), endophthalmitis (one isolate), active keratitis (12 isolates), and resolved P. aeruginosa keratitis (four isolates). Phenotype was determined in vitro by quantifying corneal epithelial cell invasion by gentamicin survival assays, and cytotoxic activity by Trypan blue exclusion assays. Genotyping was performed for genes encoding the type III secreted effectors. RESULTS: The ratio of invasive to cytotoxic strains with 95% confidence intervals (CI) was 0.83 (CI, 0.42-0.99) for conjunctival microflora isolates, 0.80 (CI, 0.54-0.94) for ocular infection isolates, and 1.0 (CI, 0.45-1.0) for strains isolated post-resolution of keratitis. Among ocular infection isolates, invasive and cytotoxic strains were significantly (P

Bilateral nocardial endophthalmitis in a prothonotary warbler (Protonotaria citrea).

A 7-year-old captive female prothonotary warbler (Protonotaria citrea) died following chronic feather and weight loss. At necropsy, the right eye had a 2 x 2 x 1 mm corneal plaque of inspissated yellow-tan material and edema of the lower eyelid. Microscopically, both eyes exhibited diffuse, severe pyogranulomatous endophthalmitis with retinal necrosis and detachment. Numerous intralesional branching, gram-positive, beaded, filamentous bacteria formed a thick mat attached to the retinal pigmented epithelium and extending into the pecten. Bacteria were strongly acid-fast positive by Fite's stain but only occasionally acid-fast positive by Ziehl-Neelsen staining, a characteristic consistent with a Nocardia spp. Infected regions demonstrated positive in situ hybridization reactivity with a probe complementary to the 16S rRNA gene of Nocardia spp. There was no evidence of primary bacterial infection in the other organs examined.

Intraocular pharmacokinetics of intravenously administered marbofloxacin in rabbits with experimentally induced acute endophthalmitis.

OBJECTIVE: To compare penetration of IV administered marbofloxacin in intraocular fluids of healthy and inflamed eyes in rabbits with endotoxin-induced endophthalmitis. ANIMALS: 35 pigmented rabbits. PROCEDURES: Endophthalmitis was induced in the right eye via intravitreal administration of Escherichia coli endotoxin. The left eye was a control eye. After 24 hours, a single dose of marbofloxacin (4 mg/kg, IV) was administered. Groups of rabbits (n = 5/group) were euthanized 0.5, 1, 2, 4, 6, 10, and 18 hours later, and blood and ocular fluids were collected. Marbofloxacin concentrations were determined via reverse-phase high-performance liquid chromatography, and pharmacokinetic analysis of the data was performed with a mono-compartmental model. RESULTS: Mean area under the aqueous concentration-time curve was significantly lower in control eyes (1.64 +/- 0.07 microg*h/mL) than in inflamed eyes (3.31 +/- 0.11 microg*h/mL). Similarly, drug penetration into aqueous humor was 33% and 65% for control eyes and inflamed eyes, respectively. Mean area under the vitreous humor concentration-time curve for control eyes(1.75 +/- 0.05 microg*h/mL) was significantly less than for inflamed eyes (2.39 +/- 0.16 microg*h/mL). In the vitreous humor, corresponding penetrations were 34% and 47%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Penetration of marbofloxacin into the aqueous and vitreous humor after IV administration was significantly enhanced by intraocular inflammation, suggesting a role for this antimicrobial in the prophylaxis or treatment of bacterial endophthalmitis caused by susceptible pathogens.