Untargeted and temporal analysis of retinal lipidome in bacterial endophthalmitis.

Bacterial endophthalmitis is a blinding infectious disease typically acquired during ocular surgery. We previously reported significant alterations in retinal metabolism during Staphylococcus (S) aureus endophthalmitis. However, the changes in retinal lipid composition during endophthalmitis are unknown. Here, using a mouse model of S. aureus endophthalmitis and an untargeted lipidomic approach, we comprehensively analyzed temporal alterations in total lipids and oxylipin in retina. Our data showed a time-dependent increase in the levels of lipid classes, sphingolipids, glycerolipids, sterols, and non-esterified fatty acids, whereas levels of phospholipids decreased. Among lipid subclasses, phosphatidylcholine decreased over time. The oxylipin analysis revealed increased prostaglandin-E2, hydroxyeicosatetraenoic acids, docosahexaenoic acid, eicosapentaenoic acid, and α-linolenic acid. In-vitro studies using mouse bone marrow-derived macrophages showed increased lipid droplets and lipid-peroxide formation in response to S. aureus infection. Collectively, these findings suggest that S. aureus-infection alters the retinal lipid profile, which may contribute to the pathogenesis of bacterial endophthalmitis.

Virulence-related genotypic differences among Bacillus cereus ocular and gastrointestinal isolates and the relationship to endophthalmitis pathogenesis.

Background: Bacillus cereus (Bc) can cause self-limiting gastrointestinal infections, but when infecting the eye, can cause rapid and irreversible blindness. This study investigated whether clinical ocular and gastrointestinal Bc isolates differed in terms of virulence-related genotypes and endophthalmitis virulence. Methods: Twenty-eight Bc ocular, gastrointestinal, and laboratory reference isolates were evaluated. Hemolysis assays were performed to assess potential differences in hemolytic activity. The presence of twenty Bc virulence-related genes was assessed by PCR. A subset of ocular and gastrointestinal isolates differing in PCR positivity for 5 virulence genes was compared to strain ATCC14579 in an experimental murine model of endophthalmitis. At 8 hours post infection, retinal function was evaluated by electroretinography, and intraocular bacterial concentrations were determined by plate counts. Results: Gastrointestinal Bc isolates were more hemolytic than the Bc ocular isolates and ATCC14579 (p < 0.0001). Bc ocular isolates were more frequently PCR-positive for capK, cytK, hblA, hblC, and plcR compared to the gastrointestinal isolates (p ≤ 0.0002). In the endophthalmitis model, mean A-wave retention did not differ significantly between eyes infected with ATCC14579 and eyes infected with the selected ocular or gastrointestinal isolates (p ≥ 0.3528). Similar results were observed for mean B-wave retention (p ≥ 0.0640). Only one diarrheal isolate showed significantly greater B-wave retention when compared to ATCC14579 (p = 0.0303). No significant differences in mean A-wave (p ≥ 0.1535) or B-wave (p ≥ 0.0727) retention between the selected ocular and gastrointestinal isolates were observed. Intraocular concentrations of ATCC14579 were significantly higher than the selected ocular isolate and 3 of the gastrointestinal isolates (p ≤ 0.0303). Intraocular concentrations of the selected ocular isolate were not significantly different from the gastrointestinal isolates (p ≥ 0.1923). Conclusions: Among the subset of virulence-related genes assessed, 5 were significantly enriched among the ocular isolates compared to gastrointestinal isolates. While hemolytic activity was higher among gastrointestinal isolates, retinal function retention and intraocular growth was not significantly different between the selected ocular and gastrointestinal isolates. These results suggest that Bc strains causing gastrointestinal infections, while differing from ocular isolates in hemolytic activity and virulence-related gene profile, are similarly virulent in endophthalmitis.

Morganella morganii and Enterococcus faecalis endophthalmitis following intravitreal injection.

BACKGROUND: Endophthalmitis following intravitreal injection is a potentially devastating complication of anti-VEGF injections. Post-injection endophthalmitis due to Enterococcus faecalis is rare, and no previous case of Morganella morganii endophthalmitis after intravitreal injection has been reported. CASE PRESENTATION: We present the first reported case of Morganella morganii and Enterococcus faecalis endophthalmitis after intravitreal injection in an immunocompetent patient in the absence of recent ocular surgery. Our patient presented with hand movement visual acuity one day after anti-VEGF injection and demonstrated no clinical improvement despite repeated intravitreal ceftazidime and vancomycin injections. A decision was made to proceed with early vitrectomy given failure of intravitreal antibiotics. Visual acuity improved to 6/90 at 12 weeks after vitrectomy without any evidence of disease recurrence. CONCLUSIONS: Post-injection endophthalmitis due to concurrent Morganella morganii and Enterococcus faecalis infections can have visually devastating consequences despite repeated empirical and targeted intravitreal antibiotics. Lack of clinical improvement following intravitreal antibiotics should warrant consideration of early vitrectomy. Our experience is a pertinent reminder of the ever-growing threat of uncommon and multi-resistant bacteria that must be considered when treating infections such as post-injection endophthalmitis.

Endophthalmitis Management Study-A Prospective Randomized Clinical Trial on Postoperative Endophthalmitis Management in India: An Interim Analysis. Endophthalmitis Management Study Report #3.

PURPOSE: An interim analysis of the Endophthalmitis Management Study to examine the outcome of inflammation score (IS)-based treatment and antibiotic susceptibility. DESIGN: A prospective randomized study. PATIENTS AND METHODS: IS was measured on a 0-4 scale from presenting signs in 4 cardinal ocular tissues. The eyes with IS <10 received vitreous tap and intravitreal antibiotics, whereas eyes with IS ≥10 received vitrectomy and intravitreal antibiotics. These eyes were randomized to 2 intravitreal antibiotic combinations: (1) vancomycin and ceftazidime and (2) vancomycin and imipenem. Microbiology workup of undiluted vitreous included microscopy, culture-susceptibility, Sanger, and targeted next-generation sequencing. The clinical and microbiology outcomes were analyzed for advanced (IS = ≥20) and less advanced (IS = <10) endophthalmitis. RESULTS: Interim analysis was performed after the Endophthalmitis Management Study recruited 56.85% (248/436) of patients and completed 54.6% (238/436) of microbiology workup. A 90-day follow-up was completed in 90.8% (168/185) of eligible people. In eyes with IS ≥20, the time to symptoms was shorter (5.8 ± 6.7 vs 8.5 ± 9.1 d; P = 0.015), and the need for additional treatment was higher (95.8% vs 53.1%; P = 0.0267). Good final vision was associated with good presenting vision (r = 0.30) and IS-based treatment decisions (r = 0.170). Microbiology positivity was 55.9%. Eyes with IS <10 had a higher Gram-positive cocci (33.9% vs 4.8%; P = 0.013) infection. Gram-positive cocci were most susceptible to vancomycin (95.7%), and Gram-negative bacilli to colistin (95.7%). CONCLUSIONS: Considering both IS and presenting vision, rather than only one of them, helps in making appropriate management decisions for acute postoperative endophthalmitis.

Endophthalmitis after intravesical bacillus Calmette-Guérin therapy for bladder cancer.

Intravesical instillation of bacillus Calmette-Guérin (BCG) is used for the maintenance treatment of some types of bladder cancer. Although rare, ocular complications can develop following intravesical BCG treatment. This is a case report of culture-positive Mycobacterium bovis BCG endophthalmitis following intravesical BCG installation. The case highlights a rare complication of BCG installation and the need for an eye examination when patients after BCG installation develop eye symptoms.

Oral administration of S-nitroso-L-glutathione (GSNO) provides anti-inflammatory and cytoprotective effects during ocular bacterial infections.

Bacterial endophthalmitis is a severe complication of eye surgeries that can lead to vision loss. Current treatment involves intravitreal antibiotic injections that control bacterial growth but not inflammation. To identify newer therapeutic targets to promote inflammation resolution in endophthalmitis, we recently employed an untargeted metabolomics approach. This led to the discovery that the levels of S-nitroso-L-glutathione (GSNO) were significantly reduced in an experimental murine Staphylococcus aureus (SA) endophthalmitis model. In this study, we tested the hypothesis whether GSNO supplementation via different routes (oral, intravitreal) provides protection during bacterial endophthalmitis. Our results show that prophylactic administration of GSNO via intravitreal injections ameliorated SA endophthalmitis. Therapeutically, oral administration of GSNO was found to be most effective in reducing intraocular inflammation and bacterial burden. Moreover, oral GSNO treatment synergized with intravitreal antibiotic injections in reducing the severity of endophthalmitis. Furthermore, in vitro experiments using cultured human retinal Muller glia and retinal pigment epithelial (RPE) cells showed that GSNO treatment reduced SA-induced inflammatory mediators and cell death. Notably, both in-vivo and ex-vivo data showed that GSNO strengthened the outer blood-retinal barrier during endophthalmitis. Collectively, our study demonstrates GSNO as a potential therapeutic agent for the treatment of intraocular infections due to its dual anti-inflammatory and cytoprotective properties.

Therapeutic potential of Bacillus phage lysin PlyB in ocular infections.

Bacteriophage lytic enzymes (i.e., phage lysins) are a trending alternative for general antibiotics to combat growing antimicrobial resistance. Gram-positive Bacillus cereus causes one of the most severe forms of intraocular infection, often resulting in complete vision loss. It is an inherently ß-lactamase-resistant organism that is highly inflammogenic in the eye, and antibiotics are not often beneficial as the sole therapeutic option for these blinding infections. The use of phage lysins as a treatment for B. cereus ocular infection has never been tested or reported. In this study, the phage lysin PlyB was tested in vitro, demonstrating rapid killing of vegetative B. cereus but not its spores. PlyB was also highly group specific and effectively killed the bacteria in various bacterial growth conditions, including ex vivo rabbit vitreous (Vit). Furthermore, PlyB demonstrated no cytotoxic or hemolytic activity toward human retinal cells or erythrocytes and did not trigger innate activation. In in vivo therapeutic experiments, PlyB was effective in killing B. cereus when administered intravitreally in an experimental endophthalmitis model and topically in an experimental keratitis model. In both models of ocular infection, the effective bactericidal property of PlyB prevented pathological damage to ocular tissues. Thus, PlyB was found to be safe and effective in killing B. cereus in the eye, greatly improving an otherwise devastating outcome. Overall, this study demonstrates that PlyB is a promising therapeutic option for B. cereus eye infections.IMPORTANCEEye infections from antibiotic-resistant Bacillus cereus are devastating and can result in blindness with few available treatment options. Bacteriophage lysins are an alternative to conventional antibiotics with the potential to control antibiotic-resistant bacteria. This study demonstrates that a lysin called PlyB can effectively kill B. cereus in two models of B. cereus eye infections, thus treating and preventing the blinding effects of these infections.

Eye fungal infections: a mini review.

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

Topical antibiotic prophylaxis before intravitreal injections: a pilot study.

PURPOSE: To explore whether topical antibiotic prophylaxis in patients scheduled for intravitreal injections achieves surface sterility in a greater proportion of subjects as compared to povidone-iodine alone. MATERIAL AND METHODS: A randomized, triple-blind clinical trial. POPULATION: patients scheduled for intravitreal injections for maculopathy. INCLUSION CRITERIA: any sex and race, age 18 years and above. Subjects were randomized into 4 groups: the first group applied chloramphenicol (CHLORAM), the second netilmicin (NETILM), the third a commercial ozonized antiseptic solution (OZONE), and the fourth applied no drops (CONTROL). OUTCOME VARIABLE: percentage of non-sterile conjunctival swabs. Specimens were collected before and after the application of 5% povidone-iodine moments before the injection. RESULTS: Ninety-eight subjects (33.7% females, 64.3% males), mean age: 70.2 ± 9.3 years (54-91). Before povidone-iodine, both the CHLORAM and NETILM group showed a lower percentage of non-sterile swabs (61.1% and 31.3% respectively), as compared to the OZONE (83.3%) and CONTROL (86.5%) groups (p < .04). However, this statistical difference was lost after the application of povidone-iodine for 3 min. Percentage of non-sterile swabs in each group after applying 5% povidone-iodine: CHLORAM 11.1%, NETILM 12.5%, CONTROL 15.4%, OZONE 25.0%. This was not statistically significant (p > .05). CONCLUSIONS: Topical antibiotic prophylaxis with chloramphenicol or netilmicin drops decreases the bacterial load on the conjunctiva. However, after the application of povidone-iodine, all groups showed a significant reduction in the percentage of non-sterile swabs, and this value was comparable among all groups. For this reason, authors conclude that povidone-iodine alone is sufficient and prior topical antibiotic prophylaxis is not indicated.

Intravitreal triple therapy with vancomycin, ceftazidime, and moxifloxacin for bacterial endophthalmitis: A Twelve-year experience.

PURPOSE: Increasing rates of antibiotic resistance in endophthalmitis have been reported. This study examines outcomes of triple therapy with intravitreal vancomycin, ceftazidime, and moxifloxacin for endophthalmitis. METHODS: Retrospective, consecutive series of all patients treated with abovementioned intravitreal antibiotics from January 2009 to June 2021. Percentages of eyes attaining greater than or equal to 20/200 and 20/50 Snellen visual acuities and adverse events were evaluated. RESULTS: 112 eyes met inclusion criteria. 63 of 112 eyes (56%) achieved a visual acuity of 20/200 during follow-up, with 39 (35%) returning to at least 20/50. In subgroup analysis, 23 of 24 (96%) eyes with post-cataract endophthalmitis obtained ≥ 20/200 acuity and 21 of 24 (88%) obtained ≥ 20/50 acuity during follow-up. There were no cases of macular infarction. CONCLUSIONS: Intravitreal moxifloxacin (160 µg/0.1 mL) was well tolerated as an adjunct to vancomycin and ceftazidime for bacterial endophthalmitis. Use of this novel combination offers several theoretical advantages compared to standard therapy with two antibiotics, including expanded gram-negative coverage and potential synergy, and may be particularly valuable in geographies where the local antibiogram supports empiric use. Further study is merited to verify the safety and efficacy profile.

Stability of Vancomycin and Ceftazidime With Prolonged Storage at -20°C.

BACKGROUND AND OBJECTIVE: Vancomycin and ceftazidime are commonly used intravitreal antibiotics for suspected bacterial endophthalmitis. Many retina surgical practices prepare aliquoted individual doses in syringes that are then stored frozen for future use, but this practice has not been well studied. This investigation aims to examine the stability of frozen vancomycin and ceftazidime. MATERIALS AND METHODS: Samples of drugs were reconstituted monthly and placed in a -20°C freezer. At the end of 3 months and again at 6 months, a newly reconstituted drug constant was created and compared to a newly created reference sample. The frozen samples were compared to a freshly produced drug solution. Using high-performance liquid chromatography (HPLC), the peak heights were compared to evaluate stability. RESULTS: The vancomycin reference sample was 100 ± 1.67%. Values over time were 97.4 ± 0.75%, 98.8 ± 0.44%, 102.1 ± 0.4%, 100.5 ± 0.12%, 101.8 ± 0.12, 101.5 ± 0.11, and 100.6 ± 1.87 for 1, 2, 3(A), 3(B), 4, 5, and 6 months, respectively. The ceftazidime reference sample was 100 ± 1.8%. Values over time were 100.7 ± 1.78%, 100.0 ± 1%, 102.3 ± 1.55%, 117.5 ± 11.6%, 112.8 ± 1.64%, 123 ± 2.8%, and 117 ± 2.5% for 1, 2, 3(A), 3(B), 4, 5, and 6 months, respectively. CONCLUSION: Both vancomycin and ceftazidime were stable over 6 months under frozen conditions at -20°C. [Ophthalmic Surg Lasers Imaging Retina 2023;54:281-283.].

Coincidence of Candida Endophthalmitis, and Aspergillus and Pneumocystis jirovecii Pneumonia in a COVID-19 Patient: Case Report.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) is associated with immune system dysfunction and makes patients vulnerable to opportunistic infections. This report presents a patient with a history of COVID-19, suffering from opportunistic infections. CASE DESCRIPTION: We reported a 64-year-old man complaining of progressive visual loss in his left eye, who had previously been hospitalized for three weeks due to COVID-19. In the ophthalmologic assessment, large foci of dense subretinal and intraretinal infiltrations involving the macula were observed (compatible with endogenous fungal endophthalmitis). Real-time PCR result of intraocular fluid was positive for Candida spp. During subsequent hospitalization, the patient also suffered from fever and productive coughs (manifestations of pneumonia caused by Aspergillus fumigatus and Pneumocystis jirovecii). In response to antibiotic therapy, the fever and coughs subsided, and the ocular examination revealed a dramatic decrease in the size of retinal infiltrations. CONCLUSIONS: In patients with severe COVID-19, long-term ICU admission and immunosuppressive drugs lead to immune system dysfunction and make the patient more susceptible to opportunistic infections. Consequently, fungal pathogens such as Aspergillus, Pneumocystis jirovecii, and Candida spp. may cause infection in different body organs. Thus, clinicians should be alert and have clinical suspicion to diagnose accurately and manage patients accordingly.

ALTERNATIVE INTRAVITREAL ANTIBIOTICS: A Systematic Review for Consideration in Recalcitrant or Resistant Endophthalmitis.

PURPOSE: To organize, categorize, and create a quick reference guide for the use of intravitreal antibiotic alternatives to the standard combination of vancomycin and ceftazidime for the treatment of endophthalmitis. METHODS: A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. The authors searched for all available information regarding intravitreal antibiotics in the last 21 years. Manuscripts were selected according to relevance, level of information, and the available data regarding intravitreal dose, potential adverse effects, bacterial coverage, and relevant pharmacokinetic information. RESULTS: The authors included 164 of 1810 manuscripts. The antibiotics were classified according to their class into fluoroquinolones, cephalosporins, glycopeptide and lipopeptide, penicillins and beta-lactams, tetracyclines, and miscellaneous. The authors also included information regarding intravitreal adjuvants for the treatment of endophthalmitis and one ocular antiseptic. CONCLUSION: The treatment of infectious endophthalmitis is a therapeutic challenge. The current review summarizes the properties of possible intravitreal antibiotic alternatives that should be considered in cases of suboptimal response to initial treatment.

IDENTIFICATION OF PATHOGENS IN THE INTRAOCULAR FLUID SAMPLES OF PATIENTS WITH ENDOGENOUS ENDOPHTHALMITIS USING RAPID NANOPORE TARGETED SEQUENCING.

IN BRIEF: Nanopore targeted sequencing showed a higher positivity rate and a shorter turnaround time than did traditional culture in identifying pathogens in the intraocular fluid samples of patients with endogenous endophthalmitis. PURPOSE: To evaluate the feasibility of clinical application of nanopore targeted sequencing (NTS) for the identification of pathogens in patients with endogenous endophthalmitis, especially those with fungus-associated endophthalmitis. METHODS: In this retrospective study, medical records and etiological results of 27 patients (34 eyes) with endogenous endophthalmitis were reviewed. The intraocular fluid samples were examined using both NTS and microbial culture. The results included the differences in detection time, positivity rate of pathogen detection, and positivity rate of fungus identification between two methods. RESULTS: NTS and microbial culture enabled the detection of etiologic agents in 89.28% and 35.71% of the samples, respectively. The difference of positivity rate between these methods was statistically significant ( P < 0.001). NTS also showed high sensitivity in both culture-positive and culture-negative samples (100% and 83.33%, respectively). Regarding culture-positive samples, the NTS results displayed a strong match with culture results. NTS showed a significantly higher positivity rate for fungal infection than did microbial culture (46.43% vs. 7.14%, P = 0.002). The average detection time of NTS was 1.11 ± 0.31 days, which was shorter than that of microbial culture (2.50 ± 0.58 days, Z = -4.686, P < 0.001). NTS technology facilitated an informed switch of intravitreal antimicrobial agents in 13 eyes. CONCLUSION: NTS, as a sensitive, specific, and timely complementary method, can be used along with traditional methods for the identification of pathogenic microorganisms in the intraocular fluid of patients with endogenous endophthalmitis.

ENDOGENOUS ENDOPHTHALMITIS CAUSED BY GROUP B STREPTOCOCCUS IN A HEALTHY, TERM NEONATE.

PURPOSE: The purpose of this study was to describe an unusual case of unilateral, endogenous endophthalmitis in an otherwise healthy, term neonate. METHODS: A 3-week-old otherwise healthy, term male infant was referred to St. Louis Children's Hospital for a second opinion of presumed panuveitis of the right eye. RESULTS: Diffusion-weighted magnetic resonance imaging demonstrating purulent intraocular contents facilitated the diagnosis of endophthalmitis. Examination of surgical vitreous samples by staining and cytology demonstrated gram-positive bacterial cocci in short chains, thereby confirming endophthalmitis. Polymerase chain reaction testing of vitreous fluid identified Streptococcus agalactiae , despite an unremarkable systemic workup and a negative prepartum maternal Group B streptococcal screen. CONCLUSION: Endogenous endophthalmitis is a rare but devastating cause of vision loss in otherwise healthy, term neonates. Prompt diagnosis may be facilitated by magnetic resonance imaging and diagnostic vitreous biopsy.