Microbiologic spectrum and susceptibility of isolates: part II. Posttraumatic endophthalmitis. Endophthalmitis Research Group

Consensus and controversies in the science of endophthalmitis management: Basic research and clinical perspectives

Infectious endophthalmitis is a severe intraocular infection caused by bacteria, or less commonly by fungi. It can occur after penetrating eye procedures, trauma, or the spread of infection from contiguous structures or via emboli from distant organs. Because of the time-critical nature of the treatment, endophthalmitis is treated with the clinical diagnosis and modified by the microbiological report of the intraocular contents. The current strategy for managing endophthalmitis relies on pre-clinical literature, case series, and one large multi-center randomized clinical trial on post-cataract surgery endophthalmitis. Culture-susceptibility of the microorganisms from undiluted vitreous guides the definitive treatment in non-responsive cases. Strategies to reduce the incidence of endophthalmitis after penetrating eye procedures have been developed concurrently with refined means of treatment. Despite these advances, outcomes remain poor for many patients. Although consensus articles have been published on managing endophthalmitis, treatment patterns vary, and controversies remain. These include (1) the use of newer methods for early and precise microbiological diagnosis; (2) the choice of intravitreal antibiotics; (3) the need for systemic therapy; (4) early and complete vitrectomy. Here, we review the current consensus and address controversies in diagnosing and managing endophthalmitis. This review is intended to familiarize physicians and ophthalmologists with different aspects of endophthalmitis management to make informed decisions.

Microbiological spectrum and antibiotic susceptibility patterns of non-viral conjunctivitis over 16 years at a tertiary eye care center in Southern India

PURPOSE

To determine the trends in the microbial spectrum and antibacterial susceptibility patterns of non-viral conjunctivitis over 16 years.

METHODS

Microbiology data were reviewed from 2006-2021 for all the patients with clinically and culture-proven infectious conjunctivitis. Conjunctival swabs and/or conjunctival scrapings were collected for microbiological workup, and the demographic and antibiotic susceptibility data were extracted from the EMR (Electronic Medical Record). For statistical analysis, χ2-test was performed.

RESULTS

Of the 1711 patients, 814 (47.57%) were culture positive and 897 (52.43%) were culture negative. Of the total culture-proven conjunctivitis cases, 775/814 (95.20%) were bacteria, and 39/814 (4.80%) were fungi. Among these bacterial isolates, 75.74% were gram-positive bacteria, while 24.26% were gram negative. The predominant gram-positive pathogens isolated were S. epidermidis (16.7%), S. aureus (17.9%) (p < 0.05), and S. pneumoniae (18.2%), while Haemophilus spp. (36.2%) (p < 0.05) was the most often isolated gram-negative bacteria (36.2%), and Aspergillus spp. was the most commonly isolated fungus (50%). The susceptibility of gram-positive bacteria to cefazoline increased from 90.46 to 98% (p = 0.01), whereas the susceptibility for gatifloxacin decreased in both gram-positive (81-41%; p < 0.0001) and gram-negative bacteria (73-58%; p = 0.02).

CONCLUSIONS

Increasing resistance of ocular isolates to mainstay antibiotics is a concern, and this data can assist healthcare practitioners in making informed choices regarding the treatment of ocular infections with ophthalmic antibiotics.

Endophthalmitis: Microbiology and Organism Identification Using Current and Emerging Techniques

Endophthalmitis is an ophthalmological emergency requiring timely and appropriate diagnosis and treatment. Microbiological methods of microscopy (Gram's staining) and culture are the current gold standard for organism identification. However, a significant proportion of endophthalmitis remains culture-negative-perhaps the inflammation is non-infectious in origin, results from a novel organism are unidentifiable or because the causative organism is non-culturable often due to pre-treatment with antibiotics. This review outlines the microbiological profile of endophthalmitis, current clinically used methods for organism identification, and the newer molecular techniques of polymerase chain reaction (PCR) and next-generation sequencing (NGS) technology as diagnostic tools for endophthalmitis. They offer the potential to improve organism identification rates and clinical outcomes in infectious diseases, representing an exciting future direction for organism identification in endophthalmitis. Based on the largest ophthalmic hospital in Australia, we highlight the key practical challenges faced by Australian diagnostic laboratories for their use in a clinical setting.

Trends in the Microbiological Spectrum of Nonviral Keratitis at a Single Tertiary Care Ophthalmic Hospital in India: A Review of 30 years

PURPOSE

The aims of this study were to assess the trends in microorganisms from patients with infectious keratitis and to assess their antibiogram patterns at a tertiary eye care center in India.

METHODS

In this retrospective observational case series, microbiological records of all corneal ulcers were reviewed from 1991 to 2020 and assessed for trends in keratitis and antibiotic susceptibility using the χ2 test.

RESULTS

Of the total of 51,747 patients, 51.13% were culture positive. A decrease in bacteria was noted from 56% to 38%, with a parallel increase in fungal isolates from 24% to 51%. Gram-positive bacteria accounted for 70.8% of the total bacteria, a trend in rise of Streptococcus pneumoniae (31%) and a decreasing trend in prevalence of Staphylococcus epidermidis was observed over 30 years. Pseudomonas aeruginosa (55.5%) was the most prevalent gram-negative pathogen, whereas Fusarium spp. (33.1%) and Aspergillus spp. (32.4%) were the most common fungal isolates. The susceptibility of gram-positive organisms to cefazolin decreased from 95.5% to 66% (P = 0.0001), amikacin from 88% to 55% (P= 0.0001), and vancomycin from 98.9% to 90.7% (P < 0.05). A similar decrease in susceptibility was also significant for gram-negative organisms with piperacillin/tazobactam and chloramphenicol (P < 0.05). A significant trend toward increasing resistance against fluoroquinolones was also observed for ciprofloxacin (gram-positive organisms: 16% to 50%; gram-negative organisms: 11.5% to 18.7%), gatifloxacin (38% to 47%), and moxifloxacin (9.4% to 29%).

CONCLUSIONS

The spectrum of keratitis has changed, and fungus is now the predominant etiology. An increasing trend in resistance to all antibiotics studied would affect the empiric treatment, also suggesting regular surveillance.

METAGENOMIC NEXT-GENERATION SEQUENCING DETECTS PATHOGENS IN ENDOPHTHALMITIS PATIENTS

PURPOSE

To investigate the utility of metagenomic next-generation sequencing (mNGS) in identifying the pathogens in endophthalmitis.

METHODS

In this prospective study, 36 cases of endophthalmitis were recruited. All patients received surgical treatment and intraocular drug lavage. The samples of vitreous or aqueous humor were extracted for mNGS and microbiological culture. The diagnostic performance of pathogens was compared between mNGS and culture.

RESULTS

The positive rates of mNGS and culture were 88.89% (32/36) and 27.78% (10/36), respectively. There was a statistically significant difference between mNGS and culture (Chi-square = 27.657; P < 0.01). Staphylococcus epidermidis, Streptococcus pneumoniae, and Klebsiella pneumoniae were the most pathogenic bacteria in traumatic, postoperative, and endogenous endophthalmitis, respectively. The concordance of pathogen identified by mNGS and culture was 70% for culture-positive cases. Antibiotic resistance genes were identified in 9 cases. There was a marginal correlation between the final visual acuity and the microbial sequence read (Spearman correlation coefficient = 0.498; P = 0.05).

CONCLUSION

Metagenomic next-generation sequencing has a higher positive rate of identifying pathogens in endophthalmitis than in culture. It can also provide information on antibiotic resistance and visual prognosis. However, caution must be taken when interpreting the results of mNGS because they may not be concordant with culture.

Evaluation of Vitreous Galactomannan and (1, 3) β-D-Glucan Levels in the Diagnosis of Fungal Endophthalmitis in Southern India

PURPOSE

To evaluate vitreous Galactomannan(GM) and 1,3 β-D-Glucan (BDG) levels in the diagnosis of fungal endophthalmitis, with emphasis on culture-negative cases.

METHODS

Vitreous from 31 clinically suspected fungal endophthalmitis patients and 11 controls were evaluated for GM and BDG using ELISA Kits. The Receiver Operating Characteristic (ROC) curves and diagnostic significance was calculated.

RESULTS

The median vitreous GM in culture-positive (60.83pg/ml) and culture-negative (59.9pg/ml) samples were higher than the (51.2pg/ml) control group. The median vitreous BDG in culture-positive (1.47pg/ml) and culture-negative (1.52pg/ml) samples were also similar, and higher than the control group (1.18pg/ml). ROC analysis showed that at a cut-off of 51.35pg/ml, the sensitivity and specificity for GM were 0.88 and 0.73.Similarly, for BDG at a cut-off of 1.18pg/ml, the sensitivity and specificity were 0.94 and 0.82 respectively.

CONCLUSION

Vitreous GM and BDG above the indicated threshold level could suggest a fungal infection, even when cultures are negative.

Epidemiological characteristics and prognostic factors of post-traumatic endophthalmitis

Objective

To examine the prognostic factors and features of post-traumatic endophthalmitis.

Methods

This retrospective study enrolled adult patients (>18 years old) diagnosed with post-traumatic endophthalmitis. Their medical records were reviewed and the patient demographic characteristics, features of injury, management, outcomes and microbiology data were analysed.

Results

A total of 131 eyes from 131 patients were enrolled. Post-traumatic endophthalmitis was more common in male patients (122 of 131 patients: 93.1%), in those aged 30–44 years (51 of 131 patients: 38.9%), in those injured with a metallic object (86 of 131 patients; 65.6%), in those with a penetrating injury (90 of 131 patients; 68.7%) and those that were injured at work (106 of 131 patients; 80.9%). The mean ± SD time of presentation to the hospital and developing endophthalmitis was 40.60 ± 19.32 h and 5.19 ± 2.55 days, respectively. Of the cultures, 84 of 131 (64.1%) were negative and 22 of 131 (16.8%) were positive for Staphylococcus species. Patients with delayed presentation, an intraocular foreign body, traumatic cataract, retinal detachment, larger wounds, positive smears and cultures and work-related injuries had worse outcomes.

Conclusion

Immediate presentation to an ophthalmic centre and timely diagnosis and intervention may lead to better outcomes.

Characterization of Polybacterial versus Monobacterial Conjunctivitis Infections in Pediatric Subjects Across Multiple Studies and Microbiological Outcomes with Besifloxacin Ophthalmic Suspension 0.6

Introduction

The choice of empiric therapy for bacterial conjunctivitis should be guided by an awareness of typical causative pathogen distributions. Bacterial conjunctivitis can be polybacterial, although pediatric-specific data are lacking.

Methods

This was a post-hoc analysis of data in pediatric subjects (1–17 years) from five bacterial conjunctivitis trials evaluating besifloxacin ophthalmic solution 0.6%.

Results

Of the 730 pediatric subjects with culture-confirmed conjunctivitis, nearly one-fourth (23.6%) had polybacterial infections and three-fourths (76.4%) had monobacterial infections at baseline. In both polybacterial and monobacterial infections, the most prevalent organisms were Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus, and Streptococcus mitis/S. mitis group. In polybacterial versus monobacterial infections, S. mitis/S. mitis group (8.7% vs 4.3%; P=0.032) and Moraxella catarrhalis (4.7% vs 0.5%; P<0.001) were identified more frequently, whereas S. pneumoniae (14.0% vs 28.1%; P<0.001) was identified less frequently, as the dominant infecting species. MICs for individual species were similar for tested antibiotics regardless of polybacterial or monobacterial infection, except Staphylococcus epidermidis for which fluoroquinolone MICs were ≥3 dilutions higher for isolates of this species sourced from polybacterial compared to monobacterial infections. Treatment with besifloxacin resulted in microbial eradication in 79.1% of polybacterial and 92.3% of monobacterial infections (P≤0.005 vs vehicle).

Discussion

One in four pediatric bacterial conjunctivitis infections is polybacterial, highlighting the need for a broad-spectrum antibiotic when choosing empiric therapy.

Efficacy of intravitreal povidone-iodine administration for the treatment of Candida albicans endophthalmitis in rabbits

This study aimed to investigate the efficacy of intravitreal povidone-iodine (PI) administration for the treatment of Candida albicans endophthalmitis. Forty New Zealand white rabbits were divided into four groups (n = 10 per group). After the induction of endophthalmitis using Candida albicans, groups A, B, and C received single intravitreal injections of 0.035 mg voriconazole, 0.3 mg PI, and their combination, respectively. Rabbits that were administered sham injections were in group D as controls. Fundus photography, vitreous culture, electroretinography (ERG), and histologic examinations of the retina were conducted on day 7. The anterior chamber flare (grade 0 to 4), severity of iritis (grade 0 to 4), and vitreous opacity (grade 0 to 3) were scored. Candida albicans was cultured in the vitreous sample. On day 7, the vitreous opacities were found in all groups. Compared to that in group D, groups A, B, and C showed a lower score for flare (p < 0.001) and iritis (p < 0.001) and less fungal growth in the vitreous culture (n = 2, 1, 1, and 10 in groups A, B, C, and D, respectively; p < 0.001). Furthermore, ERG and histologic findings demonstrated less affected a- and b-waves and damaged retinal tissues in groups A, B, and C. However, these findings were not different among groups A, B, and C. PI significantly improved Candida albicans endophthalmitis, and the effect was comparable that of the voriconazole, although some vitreous opacities remained. No synergistic effect of the combination of PI and voriconazole was observed. Intravitreal PI may be useful to treat Candida albicans endophthalmitis.

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

PURPOSE

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

DESIGN

Cross-sectional hospital-based retrospective medical records review.

PARTICIPANTS

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

METHODS

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

MAIN OUTCOME MEASURES

Clinical outcome by the causative event and causative fungus.

RESULTS

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

CONCLUSIONS

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

Clinical Presentations and Management Outcomes of Culture-Proven Mixed Bacterial and Fungal Endophthalmitis

OBJECTIVE

To report the clinical features and management outcomes of mixed fungal and bacterial endophthalmitis.

METHODS

Retrospective, consecutive non-comparative case series. Fifteen eyes of 15 patients were included from January 2009 to December 2019 with culture proven mixed fungal and bacterial endophthalmitis. Demography, clinical presentations, interventions received, and final visual and anatomical outcomes were noted. A favorable anatomic outcome was defined as preservation of the globe, absence of hypotony, attached retina, and absence of active inflammation at the last visit.

RESULTS

The mean age of patients in this series was 34.2 ± 19.6 years (range: 5-61 years). Male preponderance was found in 14 (93.3%). Eight (53.3%) eyes had open globe injury, 5(33.3%) had postoperative endophthalmitis and one (6.6%) each with endogenous endophthalmitis and post-keratitis. Pars plana vitrectomy was done in eight (53.3%) eyes whereas vitreous tap alone was done in seven (46.7%) eyes. Gram positive cocci (n = 11, 73.3%) were the commonest bacterial isolates (n = 7, 46.6%). Staphylococcus aureus (n = 3, 20%) was the most common bacterial isolate. The commonest fungi were filamentous hyaline fungi (n = 5, 33.3%). An unfavorable visual outcome (VA<20/400) was seen in all the eyes. The mean duration of follow-up was 13 ± 18.3 months. Globe salvage was possible only in five (33.3%) eyes. The bacterial isolates were highly sensitive to all of the tested antibiotics.

CONCLUSION

Mixed fungal and bacterial endophthalmitis occur commonly in a setting of open-globe trauma. The presence of fungus concurrently leads to a very poor management outcome even if the bacterial isolate sensitivity is good.

Post-Traumatic Endophthalmitis: Clinico-Microbiological Profile, Antimicrobial Susceptibility and Prognostic Factors at a Tertiary Eye Care Centre in Eastern India

Purpose: To analyse clinico-microbiological profile, antimicrobial susceptibilities, and visual prognostic factors in post-traumatic endophthalmitis (PTE).Methods: Retrospective clinico-microbiological data analysis for five years (2014-18). Prognostic factors for visual outcomes were analysed by multivariate logistic regression analysis.Results: Four hundred and eighteen patients with clinically diagnosed PTE were analysed. Culture positivity was found in 46.7% samples (44.5% vitreous, 83.3% non-vitreous). Pathogens isolated were Gram positive cocci (GPC, 49.3%, good susceptibility to vancomycin/cefazolin), Gram negative bacilli (GNB, 28.1%, <90% susceptibility to all antibiotics and 25.8% multidrug resistance), Gram positive bacilli (13.1%) and fungi (9.5%). Poor visual prognosis was associated with culture positivity, fungal or polymicrobial PTE, poor view of fundus and presence of membranes on ultrasound scans.Conclusion: GPC and GNB are the predominant pathogens in PTE, with GNB most commonly multidrug resistant. Culture positivity, polymicrobial and fungal PTE, poor view of fundus and vitreous membranes are markers of poor visual outcome.

Enterobacter endophthalmitis: Clinical settings, susceptibility profile, and management outcomes across two decades

Purpose:

To describe the clinical presentation and management of Enterobacter endophthalmitis and compare with previous in-house published literature.

Methods:

This was a retrospective interventional comparative case series involving 44 cases with culture proven Enterobacter endophthalmitis from April 2006 to August 2018 who underwent vitrectomy/vitreous biopsy, intravitreal antibiotics with or without additional procedures as appropriate. The current outcomes were compared to the outcomes previously reported a decade back from our center. The mean age at presentation, predisposing factor, number of interventions, interval between inciting event and presentation, type of intravitreal antibiotic used, anatomic, and the functional outcomes were analyzed and compared to the previous series.

Results:

There were 30 males. Mean age was 22.73 ± 21.35 years (median 14 years). Inciting event was open globe injury in 34 (77.27%) eyes, 4 (9.09%) eyes following cataract surgery, 3 (6.81%) eyes with endogenous endophthalmitis, 2 (4.54%) eyes following keratoplasty, and 1 eye (2.27%) following trabeculectomy. Presenting visual acuity was favorable (≥20/400) in 2 eyes (4.54%), at the final visit it was in 11 eyes (25%). The organisms were most sensitive to ciprofloxacin (95.12%), amikacin (90.47%), and ceftazidime (85.36%). A comparison of the current study with previous in-house study showed that number of eyes with presenting vision ≥20/400 as well as final vision ≥20/400 were comparable. Susceptibility was highest to ciprofloxacin 39 (95.12%) (previous series) and 33 (92%) (current series).

Conclusion:

Enterobacter organisms show susceptibility to ciprofloxacin, amikacin, and ceftazidime. Susceptibility profile, clinical presentations, and management remain largely similar over many years. Final outcome is unfavorable.

The Effectiveness of Intracameral Moxifloxacin Endophthalmitis Prophylaxis for Trabeculectomy

PURPOSE

To analyze the effectiveness of intracameral moxifloxacin prophylaxis in reducing acute postoperative endophthalmitis after trabeculectomy and combined trabeculectomy plus cataract extraction.

DESIGN

Retrospective clinical registry analysis.

PARTICIPANTS

Patients undergoing either trabeculectomy or trabeculectomy plus cataract extraction at Aravind Eye Hospitals (AEH) between 2009 and 2018 (inclusive).

METHODS

Electronic health records data were analyzed before and after implementation of routine intracameral moxifloxacin, and acute postoperative endophthalmitis rates were compared. During 2015, routine intracameral moxifloxacin prophylaxis was added in a step-wise fashion throughout AEH. Date of implementation was used to create group 1 (without intracameral moxifloxacin prophylaxis) and group 2 (with intracameral moxifloxacin prophylaxis).

MAIN OUTCOME MEASURES

The primary outcome was the difference in acute (≤6 weeks) postoperative endophthalmitis between groups 1 and 2. Review of culture results, visual acuity, and intraocular pressure also was performed for patients with endophthalmitis.

RESULTS

Thirty-eight thousand nine hundred eyes (group 1) did not receive intracameral moxifloxacin, whereas 19 086 eyes (group 2) did. Although the rate of noninfectious postoperative complications was not significantly different (0.81% vs. 0.67%; P = 0.07), a significantly lower rate of acute postoperative endophthalmitis was found in group 2 versus group 1 (0.03% vs. 0.08%; P = 0.03). Patients receiving intracameral moxifloxacin showed approximately 2.5-times lower odds of infection (odds ratio, 0.39 for group 2 vs. group 1; 95% confidence interval, 0.16-0.95) and almost 4-times lower odds after adjustment for covariates (odds ratio, 0.26 for group 2 vs. group 1; 95% confidence interval, 0.09-0.74). The rate of early postoperative infection after intracameral moxifloxacin introduction was lower for patients undergoing both trabeculectomy alone (0.09%-0.03%; P = 0.27) and combined trabeculectomy plus cataract extraction (0.08%-0.03%; P = 0.06). Although most cultures yielded no growth, no Staphylococcus or gram-negative growth was found for patients in group 2, who received intracameral moxifloxacin.

CONCLUSIONS

Intracameral moxifloxacin prophylaxis was associated with a nearly 4-fold lower rate of early postoperative endophthalmitis in patients undergoing trabeculectomy or combined trabeculectomy plus cataract extraction.

The cereus matter of Bacillus endophthalmitis

Bacillus cereus (B. cereus) endophthalmitis is a devastating intraocular infection primarily associated with post-traumatic injuries. The majority of these infections result in substantial vision loss, if not loss of the eye itself, within 12-48 h. Multifactorial mechanisms that lead to the innate intraocular inflammatory response during this disease include the combination of robust bacterial replication, migration of the organism throughout the eye, and toxin production by the organism. Therefore, the window of therapeutic intervention in B. cereus endophthalmitis is quite narrow compared to that of other pathogens which cause this disease. Understanding the interaction of bacterial and host factors is critical in understanding the disease and formulating more rational therapeutics for salvaging vision. In this review, we will discuss clinical and research findings related to B. cereus endophthalmitis in terms of the organism's virulence and inflammogenic potential, and strategies for improving of current therapeutic regimens for this blinding disease.

In Vitro Biofilm Formation and Antibiotic Susceptibility Patterns of Bacteria from Suspected External Eye Infected Patients Attending Ophthalmology Clinic, Southwest Ethiopia

Background

Ocular disease with its complications is a major public health problem which has significant impacts on the quality of life particularly in developing countries. An eye infection due to bacterial agents can lead to reduced vision and blindness. This study was aimed to assess the antimicrobial susceptibility pattern and biofilm-forming potential of bacteria isolated from suspected external eye infected patients in Jimma.

Method

A cross-sectional facility-based study was conducted on 319 suspect patients with external eye infections from March to June 2017 at Jimma University Medical Center (JUMC) Ophthalmology Department in Ethiopia. External ocular specimens were collected and standard operating procedures were followed to handle and culture throughout the study period. Antimicrobial susceptibility was determined by the disk diffusion method according to CLSI guidelines. Microtiter (96 wells) plate method was used to screen biofilm formation by ELISA reader at 570 nm.

Results

Out of 319 study participants with an external eye infection, the prevalence of bacterial pathogens was 46.1%. The predominant bacterial isolates were coagulase-negative staphylococcus (CoNS) (27.7%) followed by Staphylococcus aureus (19.7%). Among Gram-negative groups, Pseudomonas aeruginosa (6.8%) was the leading isolate. Increased antimicrobial resistance was observed for tetracycline (64%), erythromycin (66.7%), and penicillin (77.1%). Amoxicillin-clavulanic acid, ciprofloxacin, and gentamicin were the most effective drugs for external eye infections due to susceptibility ranging from 70 to 100% among both Gram-negative and Gram-positive groups. Methicillin-resistant S. aureus (MRSA) accounted for 13.8%. Multidrug resistance (MDR) accounted for 68.7%. The overall biofilm formation rate of bacterial ocular pathogens was 66.1%, where P. aeruginosa (40%), CoNS (34.1%), and S. aureus (31%) formed strong biofilm phenotype.

Conclusion

The prevalence rate of bacterial isolates was high. Almost all bacterial isolates were resistant to at least one or more drugs. MDR pathogens were observed increasingly among biofilm formers or vice versa.

CLINICAL PRESENTATIONS, DIAGNOSIS, AND MANAGEMENT OUTCOMES OF CURVULARIA ENDOPHTHALMITIS AND A REVIEW OF LITERATURE

PURPOSE

To describe the clinical presentation and management of Curvularia endophthalmitis and compare with previous published literature.

METHODS

Retrospective interventional comparative case series and literature review. Eight cases with culture-proven Curvularia endophthalmitis from January 2000 to March 2018 underwent vitrectomy/vitreous biopsy, intravitreal antibiotic with or without additional procedures as appropriate. The undiluted vitreous biopsy was subjected to microbiologic evaluation. Pre-existing literature was reviewed, and the current outcomes were compared with them. The mean age at presentation, etiology, number of interventions, interval between inciting event and presentation, type of intravitreal antifungal used, anatomical, and the functional outcomes were reported and compared with pre-existing literature. A favorable anatomical outcome was defined as preservation of the globe, absence of hypotony, attached retina, and absence of active inflammation at the last visit.

RESULTS

In the current series, there were 4 men and 4 women. Mean age at presentation was 34.5 ± 13.51 years (median 30 years). Inciting event was open-globe injury in five cases and cataract surgery, trabeculectomy, and endogenous cause in one case each. Presenting visual acuity was ≥20/400 in 3 cases at presentation and 5 cases at the last visit. One case with staphyloma and endophthalmitis underwent evisceration for a painful blind eye. The patients in the current series were much younger than those described previously.

CONCLUSION

Presentation and diagnosis of Curvularia can be delayed especially in postoperative cases. Early and appropriate management with multiple interventions can result in an acceptable visual and anatomical outcome.

Targets of immunomodulation in bacterial endophthalmitis

Bacterial infection of the posterior segment of the eye (endophthalmitis) leads to a robust host response that often results in irreversible damage to the layers of the retina, significant vision loss, and in some patients, enucleation of the globe. While a great deal of effort has gone into understanding the role of bacterial virulence factors in disease initiation and propagation, it is becoming increasingly clear that the host response to infection plays a major role in causing the damage associated with endophthalmitis. Researchers have identified the host receptors which detect infecting organisms and initiate the cascade of events that result in inflammation. This inflammation may damage nonregenerative tissues of the eye while attempting to clear the infection. Both Gram-positive and Gram-negative bacteria can cause endophthalmitis. These organisms initiate an immune response by activating toll-like receptor (TLR) pathways. Once an inflammatory response is initiated, the expression of immunomodulators, such as proinflammatory chemokines and cytokines, affect the recruitment of PMNs and other inflammatory cells into the eye. We and others have reported that knockout mice that do not express specific inflammatory pathways and molecules have an attenuated response to infection and retain significant retinal function. These findings suggest that host immune mediators are important components of the response to infections in the posterior segment of the eye, and the timing and level of their production may be related to the severity of the damage and the ultimate visual outcome. If that is the case, a better understanding of the complex and often redundant role of these pathways and inflammatory mediators may identify host molecules as potential anti-inflammatory therapeutic targets. This review highlights potential anti-inflammatory targets during acute inflammation in endophthalmitis, compares and contrasts those with findings in other models of ocular inflammation, and translates current immunomodulatory strategies for other types of infection and inflammation to this blinding disease. Given the poor visual outcomes seen in patients treated with antibiotics alone or in combination with corticosteroids, immunomodulation in addition to antibiotic therapy might be more effective in preserving vision than current regimens.

Trends in microbiological spectrum of endophthalmitis at a single tertiary care ophthalmic hospital in India: a review of 25 years

PURPOSE

To determine trends in the microbial spectrum of endophthalmitis over the past 25 years and to review its antibiotic susceptibility patterns over the last 10 years.

METHODS

Microbiology records of culture-positive endophthalmitis cases from 1991 to 2015 were reviewed. Additionally, data between 2005 and 2015 was also analyzed for trends in antibiotic susceptibility.

RESULTS

Of the total of 9278 patients, 3319 (35.7%) were culture positive and included bacteria (2840/3319, 85.56%), fungi (387/3319, 11.66%), and mixed cultures (92/3319, 2.7%). Gram-positive bacteria accounted for 67.68% (1922/2840) of the total bacteria seen, with the most prevalent pathogen being Streptococcus pneumoniae and Staphylococcus epidermidis. Among the gram-negative organisms Pseudomonas aeruginosa was the most prevalent while. Aspergillus flavus was the most common fungus isolated and Candida sp. accounted for 6.9% of the total fungi isolated. There was no significant change in the trends of bacteria isolated during the study period. Overall susceptibility patterns showed that gram-positive bacteria were most susceptible to vancomycin (96%) and fluoroquinolones (89%). The resistance to ceftazidime increased from 31% in 2005 to 62% in 2015 (P = 0.006) and amikacin decreased from 36% in 2005 to 33% in 2015 (P = 0.782). Although a significant trend (P < 0.001) toward increasing microbial resistance against cephalosporins and fluoroquinolones was observed, decreasing microbial resistance against glycopeptides and aminoglycosides was also detected.

CONCLUSION

The spectrum of pathogens causing endophthalmitis at our institute remained similar over the study period. These findings impact the empiric treatment and choice of antibiotics in patients with endophthalmitis.

New insights into culture negative endophthalmitis by unbiased next generation sequencing

The proof-of-concept, study to investigate the presence of microorganisms in presumed infectious endophthalmitis using Next generation sequencing (NGS) was carried out in vitreous biopsies from 34 patients with endophthalmitis, and thirty patients undergoing surgery for non-infectious retinal disorders as controls. Following DNA extraction using the Qiagen mini kit and PCR amplification of the V3–V4 regions of the bacterial 16S rRNA and ITS 2 region of fungus, they samples were sequenced on an Illumina HiSeq 2500 Machine. Paired reads were curated, taxonomically labeled, and filtered. Culture based diagnosis was achieved in 15/34 (44%) patients while NGS diagnosed the presence of microbes in 30/34 (88%) patients (bacteria in 26/30, fungi in 2/30, mixed infections in 2/30 cases). All 30 controls were negative for bacteria or fungus by NGS. There was good agreement between culture and NGS for culture-positive cases. Among culture negative cases, DNA of common culturable bacteria were identified like Streptococcus sp., Staphylococcus sp., Pseudomonas sp., Gemella sp., Haemophilus sp., Acinetobacter sp. The specificity of NGS with culture and clinical diagnosis was found to be 20% and 100% respectively and sensitivity of NGS with culture and clinical diagnosis was found to be 87.5% and 88% respectively. NGS appears to be promising diagnostic platform for the diagnosis of infectious culture negative endophthalmitis.

Diagnostic value of pediatric blood culture bottles for acute postoperative endophthalmitis

OBJECTIVE

To report our experience using conventional culture methods (CM) and pediatric blood culture bottles (PBCBs) for vitreous sample culture of acute postoperative endophthalmitis.

METHODS

A retrospective study was conducted at the Department of Ophthalmology, Hospital das Clinicas, HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, BR, from January 2010 to December 2015, and it included 54 patients with clinically suspected acute postoperative endophthalmitis. Vitreous samples were obtained by vitreous tap or vitrectomy. Samples from January 2010 to December 2011 were cultivated in CM, whereas samples from January 2012 to December 2015 were inoculated in PBCBs. The measured outcome was the yield of positive cultures.

RESULTS

Twenty cases were included in the CM group, and 34 cases were included in the PBCB group. The yield of positive cultures in PBCBs (64.7%) was significantly higher than that in conventional CM (35%, p=0.034). Staphylococcus epidermidis and Streptococcus viridans were the two most commonly found agents.

CONCLUSION

PBCBs can be used successfully in clinically suspected endophthalmitis. The method showed a higher yield of positive cultures than the conventional method. This technique appears to have several advantages over the traditional method: it saves time, as only one medium needs to be inoculated; transportation to a laboratory is easier than in the traditional method, and there is no need to maintain a supply of fresh agar media. The use of PBCBs may be recommended as the primary method for microbiological diagnosis and is especially suitable for office settings and remote clinics.

The Role of Pneumococcal Virulence Factors in Ocular Infectious Diseases

Streptococcus pneumoniae is a gram-positive, facultatively anaerobic pathogen that can cause severe infections such as pneumonia, meningitis, septicemia, and middle ear infections. It is also one of the top pathogens contributing to bacterial keratitis and conjunctivitis. Though two pneumococcal vaccines exist for the prevention of nonocular diseases, they do little to fully prevent ocular infections. This pathogen has several virulence factors that wreak havoc on the conjunctiva, cornea, and intraocular system. Polysaccharide capsule aids in the evasion of host complement system. Pneumolysin (PLY) is a cholesterol-dependent cytolysin that acts as pore-forming toxin. Neuraminidases assist in adherence and colonization by exposing cell surface receptors to the pneumococcus. Zinc metalloproteinases contribute to evasion of the immune system and disease severity. The main purpose of this review is to consolidate the multiple studies that have been conducted on several pneumococcal virulence factors and the role each plays in conjunctivitis, keratitis, and endophthalmitis.

Prophylactic intravitreal antibiotics reduce the risk of post-traumatic endophthalmitis after repair of open globe injuries

PURPOSE

To investigate efficacy of prophylactic intravitreal antibiotics in reducing incidence of endophthalmitis after repair of open globe injuries. At King Abdulaziz University Hospital, a standard protocol of intravenous vancomycin and ceftazidime was used in all cases.

METHODS

Charts of 353 patients who presented between January 2010 and January 2014 with open globe injury were retrospectively reviewed. In addition, the standard protocol in this cohort included prophylactic intravitreal antibiotics in high-risk cases at time of primary repair. High-risk cases were identified based on the presence of one or more of the following risk factors: dirty wound, retained intra-ocular foreign body (IOFB), rural setting, delayed primary repair of >24 hr and ruptured lens capsule. Rate of endophthalmitis in this recent cohort was compared with that of a previous cohort admitted for primary repair between May 1996 and May 2008 (641 patients). In the previous cohort, protocol did not include prophylactic intravitreal antibiotics.

RESULTS

Rates of clinically suspected endophthalmitis and culture-positive endophthalmitis were higher in previous cohort (24 of 641 eyes; 3.7% and 12 of 641 eyes; 1.9%, respectively) compared to recent cohort (six of 353 eyes; 1.7% and two of 353 eyes; 0.6%, respectively). In high-risk groups, rates of suspected endophthalmitis and culture-positive endophthalmitis were higher in previous cohort (19 of 345 eyes; 5.5% and 12 of 345 eyes; 3.5%, respectively) compared to the recent cohort (five of 200 eyes; 2.5% and two of 200 eyes; 1.0%, respectively).

CONCLUSION

Prophylactic intravitreal antibiotics reduce risk of endophthalmitis after repair of open globe injuries.

Clinicomicrobiological profile of endophthalmitis: A 10 year experience in a Tertiary Care Center in North India

PURPOSE

To determine the clinicomicrobiological profile of infectious agents and their antibiotic susceptibility in different type of endophthalmitis.

METHODS

A retrospective review of clinical and microbiological records from January 2001 to December 2010, was performed in 1110 patients diagnosed with different type of endophthalmitis (postoperative, posttraumatic, endogenous and post keratitis) to record the demographic details, clinical presentations; microbiological agents isolated with their antimicrobial sensitivity pattern. Antimicrobial susceptibility testing for various culture positive isolates (bacterial/fungal) was performed by the disc diffusion technique.

RESULTS

Out of the 1110 intra-ocular specimens processed, 384 (34.6%) were positive for bacteria. S epidermidis was the most predominant isolate accounting for 42.7% of all bacteria obtained, followed by Pseudomonas aeruginosa (24.5%). Besides Pseudomonas, Acinetobacter spp. were the next common gram negative bacilli detected (8.3%) followed by Klebsiella, E. coli, Enterobacter and Alkaligenes in 2.6%, 0.8%, 0.8% and 0.5% cases respectively. The predominant fungal species were Aspergillus spp., in 36.1%, followed by Fusarium spp. in 26.4% cases. Overall susceptibility pattern in our study showed that gram positive bacteria were most susceptible to glycopeptides like vancomycin (80-100%) and fluoroquinolones (87-91%). The sensitivity pattern of gram negative organisms like Pseudomonas and Klebsiella towards fluoroquinolones ranged between 61% - 82%.

CONCLUSION

S epidermidis was the most common bacteria isolated in postoperative and posttraumatic endophthalmitis, Pseudomonas aeruginosa was the most common bacterial isolated in posttraumatic endophthalmitisAmongst fungi Aspergillus was the most common organism.

POSTTRAUMATIC ENDOPHTHALMITIS: An 18-Year Case Series

PURPOSE

To describe the demographics, characteristics, management, and visual outcomes of eyes diagnosed with endophthalmitis after open globe injury.

METHODS

Retrospective cohort analysis of all patients diagnosed with endophthalmitis after open globe injury from 1997 to 2015 at University Hospital, Newark, NJ.

RESULTS

Twenty-six eyes were identified (all male patients; mean age: 37 ± 15 years). Cultures were positive in 16 eyes (62%), with Staphylococcus species (7 eyes, 44%) being the most common organism. Twelve eyes (46%) presented with open globe injury and concurrent endophthalmitis; 14 eyes (54%) developed endophthalmitis a mean of 14 days after open globe repair (OGR; 1 outlier of 98 days excluded). All eyes were managed with systemic and intravitreal antibiotics. The presence of intraocular foreign body (P < 0.05) and delayed primary OGR (P < 0.03) were significantly more common with concurrent versus post-OGR endophthalmitis. Four (29%) eyes in the post-OGR endophthalmitis group had corneal wound leak after OGR. Four (15%) eyes with no light perception vision were enucleated. Ten (40%) of 25 eyes with documented best-corrected visual acuity had final best-corrected visual acuity ≥20/200; final best-corrected visual acuity ranged from no light perception to 20/20.

CONCLUSION

The presence of intraocular foreign body and delayed presentation were significantly more common with concurrent endophthalmitis. Twenty-nine percent of eyes that presented with endophthalmitis after OGR had a wound leak. Final best-corrected visual acuity ≥20/200 was achieved in 40% of cases.

Risk Factors for Culture-Positive Endophthalmitis after Repair of Open Globe Injuries

Purpose

To identify risk factors for the development of culture-positive endophthalmitis after repair of open globe injuries.

Methods

We retrospectively reviewed the medical records of 629 consecutive patients with open globe injuries admitted to King Abdulaziz University Hospital between May 1996 and January 2008.

Results

Endophthalmitis developed in 12 (1.9%) patients. The following factors were significantly associated with endophthalmitis by univariate analysis: delayed presentation (>24 hours) (p=0.008), rural address (p=0.013), and dirty wound (p=0.012). Logistic regression analysis identified dirty wound to be associated with the development of endophthalmitis (odds ratio = 11.6; 95% confidence interval [CI] = 2.67–50.6). On logistic regression analysis, presence of retained intraocular foreign body (IOFB) in association with rural address (odds ratio = 11.0; 95% CI = 1.44–83.3) or dirty wound (odds ratio = 9.2; 95% CI = 1.22–69.1) was associated with development of endophthalmitis. Endophthalmitis was a significant negative predictor for final good visual outcome (p=0.00261) and was significantly associated with hypotony (p=0.033).

Conclusions

Delayed presentation, rural address, and dirty wound were associated with development of endophthalmitis. Retained IOFB in association with rural address or dirty wound was associated with a particularly high risk of endophthalmitis.

CLINICAL PRESENTATION, MICROBIOLOGIC PROFILE AND FACTORS PREDICTING OUTCOMES IN BACILLUS ENDOPHTHALMITIS

PURPOSE

To describe the clinical presentation, microbiologic profile, and factors predicting outcomes in Bacillus endophthalmitis.

METHODS

Retrospective interventional case series. Eighty-six patients with culture-proven Bacillus endophthalmitis, from January 2001 to December 2015, underwent vitrectomy/vitreous biopsy and intravitreal antibiotic with or without steroid as appropriate. The undiluted vitreous biopsy was subjected to microbiologic evaluation. The duration of symptoms, presenting visual acuity, organisms isolated, influence of intravitreal dexamethasone with intravitreal antibiotics, and type of initial intervention were examined for any clinical and statistical correlation in terms of odds ratio with the final visual outcome.

RESULTS

Trauma was the commonest etiology (n = 75; 87.2%). Mixed infection with other bacteria was seen in 11 patients. All Bacillus species were sensitive to gentamicin followed by ciprofloxacin (n = 85; 98.83%) and vancomycin (n = 81; 94.18%). Odds in favor of a favorable visual outcome were seen with clinical treatment within 48 hours of the symptoms (OR 25.47, 95% CI 2.45-254.16, P = 0.006), better presenting vision (OR 31.21, 95% CI 2.96-323.64, P = 0.004), and absence of polymicrobial infection (OR 18.03, 95% CI 0.9-344.4, P = 0.05). Only 20% of all treated patients regained ambulatory vision, and one fifth of all of them developed phthisis.

CONCLUSION

Patients diagnosed with Bacillus endophthalmitis merit aggressive vitreous intervention guided by the culture-sensitivity report. Despite early and appropriate treat ment, the outcomes are generally poor.

Posttraumatic Endophthalmitis in children: Epidemiology, Diagnosis, Management, and Prognosis

Pediatric posttraumatic endophthalmitis presents with great complexities and challenges arising due to delayed presentation, difficulty in eliciting an accurate history, or trauma with unusual and highly contaminated objects. The possibility of initial misdiagnosis as panuveitis, metastatic endophthalmitis, and masquerade syndrome is also very high, which results not only in several unwarranted investigations being performed, but also a delay in the initiation of treatment. The standard treatment remains primary repair of the wound, intravitreal therapy with broad spectrum antibiotics, and parsplana vitrectomy. Despite appropriate intervention, visual outcome in children with posttraumatic endophthalmitis is dampened by additional factors like poor compliance with postoperative instructions and high risk of amblyopia. Hence, it is important to recognize that posttraumatic endophthalmitis in children differs from that in adults in several ways. We made a very tailored effort to review the published literature pertaining to posttraumatic endophthalmitis in children and herein present the results of our search.

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

PURPOSE

To report clinical and microbiological profile of patients with ocular candidiasis.

MATERIALS AND METHODS

Patients with ocular candidiasis were retrospectively identified from microbiology records. Significant isolates of Candida species were identified by Vitek 2 compact system. Minimum inhibitory concentration (MIC) of antifungal agents such as amphotericin B, itraconazole, voriconazole, fluconazole and caspofungin was determined by E test and of natamycin by microbroth dilution assay. Data on treatment and outcome were collected from medical records.

RESULTS

A total of 42 isolates of Candida were isolated from patients with keratitis-29, endophthalmitis-12 and orbital cellulitis-1. The most common species isolated was Candida albicans (12-keratitis, 4-endophthalmitis, 1-orbital cellulitis). All except one isolate were susceptible to amphotericin B. MIC of caspofungin was in the susceptible range in 28 (96.5%) corneal isolates while 12 out of 29 (41.3%) corneal isolates were sensitive to fluconazole. Resistance to voriconazole was seen in four corneal isolates. All isolates were susceptible to natamycin and all except two isolates were resistant or susceptible dose-dependent to itraconazole. Outcome of healed ulcer was achieved in 12/18 (66.6%) patients treated medically, while surgical intervention was required in 11 patients. Among the isolates from endophthalmitis patients, 11/12 were susceptible to amphotericin B, 6/12 to voriconazole and all to natamycin. Ten out of 11 patients (one patient required evisceration) with endophthalmitis were given intravitreal amphotericin B injection with variable outcome.

CONCLUSIONS

Ocular candidiasis needs early and specific treatment for optimal results. Candida species continue to be susceptible to most commonly available antifungals including amphotericin B, voriconazole and natamycin.

Staphylococcus aureus and its Bearing on Ophthalmic Disease

PURPOSE

To review antibiotic resistance associated with S. aureus endophthalmitis and the virulence of S. aureus.

METHODS

Review of the current and prospective approaches for treating S. aureus endophthalmitis.

RESULTS

Bacterial endophthalmitis remains to be a major threat for vision. S. aureus endophthalmitis specifically, carries a poor visual prognosis making early diagnosis and treatment crucial. Methicillin resistant Staphylococcus aureus (MRSA) endophthalmitis represents a significant number of S. aureus endophthalmitis cases. MRSA with reduced susceptibility to glycopeptide antibiotics such as vancomycin (vancomycin intermediate S. aureus, VISA) have also emerged in the ocular infections, and there has been a rise in S. aureus resistance to new and old generation fluoroquinolones that are commonly used for prophylaxis after intravitreal injections and intraocular surgeries.

CONCLUSIONS

With the rise in the number of penetrating procedures in the ophthalmology practice and the parallel rise in antibiotic resistance, prophylaxis and awareness of the antimicrobial resistance profiles remain crucial and the identification of novel antimicrobials is essential.

Risk of Fungal Endophthalmitis Associated with Cataract Surgery: A Mini-Review

Fungal endophthalmitis is a rare complication after cataract surgery and is associated with significant morbidity including vision loss. The common causative fungal pathogens implicated in fungal endophthalmitis after cataract surgery include Candida species (spp.) and molds such as Aspergillus spp. and Fusarium spp. Early diagnosis and effective antifungal treatment after a high index of clinical suspicion are required to reduce unfavorable complications and to preserve eye function. This review discusses epidemiology, pathogenesis, clinical features, diagnosis, management, and outcomes associated with fungal endophthalmitis after cataract surgery.

Recent Clinical Manifestation and Prognosis of Fungal Endophthalmitis: A 7-Year Experience at a Tertiary Referral Center in Korea

This study analyzed the recent causes, prognosis, and treatment strategies for fungal endophthalmitis. A retrospective review of patients who were diagnosed with fungal endophthalmitis at our center was conducted. The fungal organisms isolated from each patient and the visual prognosis according to the route of infection and treatment method were analyzed. A total of 40 eyes from 30 patients with fungal endophthalmitis were included in this study. Candida species were the most common causative organisms in 35 of 40 eyes. Endogenous and exogenous endophthalmitis were observed in 33 and 7 eyes, respectively. Pre- and post-treatment best-corrected visual acuity (BCVA) was not significantly different between endogenous endophthalmitis and exogenous endophthalmitis. The 40 eyes were treated using the following modalities: intravitreal antifungal agent injection with intravenous antifungal agent (16 eyes), vitrectomy with intravenous antifungal agent (14 eyes), intravenous antifungal agent alone (9 eyes), and evisceration (1 eye). Post-treatment BCVA only significantly improved after treatment in the vitrectomy group. Candida species were the most common cause of fungal endophthalmitis, irrespective of the route of infection. The visual prognosis of fungal endophthalmitis was generally poor. In conclusion, if the general condition of the patient tolerates a surgical procedure, prompt vitrectomy and intravitreal injection of antifungal agents can improve visual acuity.

Exogenous fungal endophthalmitis: an analysis of isolates and susceptibilities to antifungal agents over a 20-year period (1990-2010)

PURPOSE

To describe the isolates and susceptibilities to antifungal agents for patients with culture-proven exogenous fungal endophthalmitis.

DESIGN

Noncomparative case series.

METHODS

The clinical records of all patients treated for culture-proven exogenous fungal endophthalmitis at a university referral center from 1990 to 2010 were reviewed. Specimens initially used for diagnosis were recovered from the microbiology department and then underwent antifungal sensitivity analysis.

RESULTS

The antifungal susceptibilities of 47 fungal isolates from culture-positive fungal endophthalmitis are reported. Included are 14 isolates from yeast and 33 from mold. The mean (±standard deviation) minimum inhibitory concetrations (MICs) for amphotericin B (2.6 ± 3.5 μg/mL), fluconazole (36.9 ± 30.7 μg/mL), and voriconazole (1.9 ± 2.9 μg/mL) are reported. Presumed susceptibility to oral fluconazole, intravenous amphotericin B, intravitreal amphotericin B, oral voriconazole, and intravitreal voriconazole occurred in 34.8%-43.5%, 0-8.3%, 68.8%, 69.8%, and 100% of isolates, respectively.

CONCLUSIONS

Based on this laboratory study of isolates from exogenous fungal endophthalmitis, intravitreal voriconazole appears to provide the broadest spectrum of antifungal coverage and, as such, may be considered for empiric therapy of endophthalmitis caused by yeast or mold.

Intraocular penetration of systemic antibiotics in eyes with penetrating ocular injury

PURPOSE

To determine whether penetrating scleral or corneal injury can enhance intraocular penetration of systemic moxifloxacin, vancomycin, and ceftazidime.

METHODS

Thirty rabbits were divided into 3 groups for each antibiotic and then further subdivided to receive either scleral or corneal injury to the right eye. The left eye served as a control. Intravenous antibiotics were given following injury, and eyes were subsequently enucleated. Vitreous antibiotic concentration was determined by high-performance liquid chromatography analysis. Plasma concentration was measured for comparison.

RESULTS

Intravitreal moxifloxacin concentration was unchanged by injury. Minimum inhibitory concentration (MIC90) was achieved in the vitreous against the most common gram-positive endophthalmitis-causing organisms. Intravitreal vancomycin levels were not enhanced by injury and did not reach the MIC90 for gram-positive organisms commonly causing intraocular infection. Intravitreal ceftazidime was increased in the injured eyes, 67% and 73% higher in scleral and corneal injury eyes. It reached MIC90 of many gram-negative bacteria.

CONCLUSIONS

Intravitreal antibiotic penetration of systemic antibiotics with or without penetrating ocular injury varies depending on the antibiotic. For prevention or treatment of gram-positive-bacteria-causing endophthalmitis, intravitreal vancomycin is necessary and provides the most reliable coverage. Systemic ceftazidime can be used for many gram-negative bacteria, but intravitreal injection is recommended for better coverage, especially for more-potent organisms. Systemic moxifloxacin can be considered for most gram-positive and -negative infections due to its excellent intraocular penetration and broad coverage, but the patient's previous history of its topical use and increasing resistance patterns must be considered.

Causative organisms of post-traumatic endophthalmitis: a 20-year retrospective study

Background

A wide range of organisms that enter the eye following ocular trauma can cause endophthalmitis. This study was to investigate the spectrum of pathogens and antibiotic susceptibility of bacterial isolates from a large cohort of post-traumatic endophthalmitis cases.

Methods

A retrospective study of 912 post-traumatic endophthalmitis patients treated at a tertiary eye-care center in China was performed. The associations between risk factors and the most common isolated organisms were investigated by Chi square Test. The percent susceptibilities for the first 10 years (1990–1999) and the second 10 years (2000–2009) were compared by Chi square test. p < 0.05 was considered statistically significant.

Results

Three-hundred-forty-seven (38.1%) cases of endophthalmitis were culture-positive, and 11 (3.2%) showed mixed infections (Gram-negative bacilli and fungi), yielding a total of 358 microbial pathogens. Culture proven organisms included 150 (41.9%) Gram-positive cocci, 104 (29.1%) Gram-negative bacilli, 44 (12.3%) Gram-positive bacilli, and 60 (16.8%) fungi. The coagulase-negative staphylococcal (CNS) species S. epidermidis (21.8%) and S. saprophyticus (12.0%) were the predominant pathogens, followed by Bacillus subtilis (8.7%), Pseudomonas aeruginosa (7.8%), and Escherichia coli (6.4%). Delayed repair over 24 h (p < 0.001) and metallic injury (p < 0.01) were significantly associated with positive culture of CNS. The most frequent fungal species were Aspergillus (26/60), followed by yeast-like fungi (18/60). P. aeruginosa was relatively sensitive to ciprofloxacin (83.3%), cefoperazone (75%), tobramycin (75%), cefuroxime (75%), and ceftazidime (75%) during the second decade. Multi-drug resistance was observed in the predominant Gram-negative bacteria.

Conclusion

We identified a broad spectrum of microbes causing post-traumatic endophthalmitis, with Gram-positive cocci the most frequently identified causative organism, followed by Bacillus species, fungi, and mixed infections. CNS infection was statistically associated with delayed repair and metallic injury. Variation in antibiotic susceptibility was observed among isolated bacteria and between different periods. Ciprofloxacin and ceftazidime in the first and second decades of the study, respectively, showed the highest activity against bacterial post-traumatic endophthalmitis. For infections caused by P. aeruginosa, a combination therapy of ciprofloxacin, tobramycin, and one of the cephalosporins might provide optimal coverage according to data from the second decade.

Identification of polybacterial communities in patients with postoperative, posttraumatic, and endogenous endophthalmitis through 16S rRNA gene libraries

Endophthalmitis is a potential vision-threatening complication following surgical procedures (postoperative endophthalmitis [POE]), trauma (posttraumatic endophthalmitis [PTE]), and bacteremic seeding of the eye from a distant infection site (endogenous endophthalmitis [EE]). Several studies have revealed the polybacterial characteristics of endophthalmitis, which make the administration of antibiotics to treat the disease challenging. However, until now, the polybacterial communities of POE, PTE, and EE have not been precisely studied. Hence, the present study was designed to identify the bacterial community of endophthalmitis through 16S rRNA gene libraries. Of the 40 intraocular samples tested, 30 libraries were constructed with bacterial nested-PCR-positive samples. The obtained recombinant clones were screened through amplified rRNA gene restriction analysis (ARDRA) to identify unique clones. The multiple types of ARDRA patterns (P=0.345) and diverse bacterial sequences (P=0.277) within the libraries revealed the polybacterial nature of infection in POE, PTE, and EE. Moreover, to the best of our knowledge, this is the first report on polybacterial infection in EE. Gram-positive bacteria, including Bacillus spp. (n=19), Streptococcus spp. (n=18), Staphylococcus spp. (n=6), Exiguobacterium spp. (n=3), Gemella spp. (n=2), Enterococcus spp. (n=2), a Lysinibacillus sp. (n=1), a Clostridium sp. (n=1), and a Nocardia sp. (n=1), and Gram-negative bacteria, including Serratia spp. (n=18), Pseudomonas spp. (n=10), Enterobacter spp. (n=8), Acinetobacter spp. (n=3), Pantoea spp. (n=3), a Haemophilus sp. (n=1), and a Massilia sp. (n=1), were identified. Interestingly, among them, 10 bacterial species were not previously reported to be associated with endophthalmitis or other ocular infections. Besides, the presence of 4 unidentifiable clones suggests the possibility of novel organisms that might cause eye infections. Therefore, it is recommended that, in addition to the polybacterial nature of POE, PTE, and EE infections, the spectrum of the pathogenic bacterial community identified in this work should be considered while administering antibiotic therapy in suspected endophthalmitis cases.

Endophthalmitis after open globe injuries: changes in microbiological spectrum and isolate susceptibility patterns over 14 years

Background

The objective of this study was to evaluate the microbiologic spectrum and antimicrobial susceptibility of isolates in post-traumatic endophthalmitis and compare with our earlier published report. A retrospective review was conducted on 581 consecutive patients with culture-proven post-traumatic endophthalmitis at L. V. Prasad Eye Institute, India, from January 2006 to March 2013.

Findings

A total of 620 isolates from 581 patients were identified (565 bacteria and 55 fungi). The most common isolate was Bacillus spp. (106/620, 17.1%) closely followed by Streptococcus pneumoniae (105/620, 16.9%), and coagulase-negative Staphylococci (97/620, 15.6%). In our earlier report, the commonest bacteria included Streptococcus spp. (30/139, 21.6%) and gram-positive coagulase-negative micrococci (26/139, 18.7%). Gram-positive isolates were usually susceptible to vancomycin (98.2%). Gram-negative isolates were generally susceptible to gatifloxacin (92.9%), ofloxacin (89.4%), chloramphenicol (88.6%, Pseudomonas isolates were often resistant), amikacin (83.5%), and ceftazidime (77.2%). Fourteen years ago, the most sensitive antibiotic was ciprofloxacin for both gram-positive bacteria (95.12%) and gram-negative bacteria (100%).

Conclusions

The microbiological spectrum of post-traumatic endophthalmitis has remained unchanged over the last 14 years, and Bacillus spp. continues as the most common infecting organism. Vancomycin is the drug of choice for empiric coverage of gram-positive bacteria. Susceptibility of gram-negative bacteria to commonly used antimicrobials (amikacin and ciprofloxacin) has decreased by 10% - 15% and to ceftazidime has increased by 10.5%.

Endophthalmitis

Endophthalmitis means bacterial or fungal infection inside the eye involving the vitreous and/or aqueous humors. Most cases are exogenous and occur after eye surgery, after penetrating ocular trauma, or as an extension of corneal infection. An increasing number of cases are occurring after intravitreal injections of anti-vascular endothelial growth factor (VEGF) medications. Endophthalmitis may also be endogenous, arising from bacteraemic or fungaemic seeding of the eye. The infected eye never serves as a source of bacteraemia or fungaemia, however. The most common pathogens in endophthalmitis vary by category. Coagulase-negative staphylococci are the most common causes of post-cataract endophthalmitis, and these bacteria and viridans streptococci cause most cases of post-intravitreal anti-VEGF injection endophthalmitis, Bacillus cereus is a major cause of post-traumatic endophthalmitis, and Staphylococcus aureus and streptococci are important causes of endogenous endophthalmitis associated with endocarditis. In Taiwan and other East Asian nations, Klebsiella pneumoniae causes most cases of endogenous endophthalmitis, in association with liver abscess. Endogenous fungal endophthalmitis in hospitalized patients is usually caused by Candida species, particularly Candida albicans. Acute endophthalmitis is a medical emergency. The most important component of treatment is the intravitreal injection of antibiotics, along with vitrectomy in severe cases. Systemic antibiotics should be used in cases of endogenous endophthalmitis and exogenous fungal endophthalmitis, but their role in exogenous bacterial endophthalmitis is uncertain. Repeated intravitreal injections of antibiotics may be necessary if there is no response to the initial therapy. Many eyes that receive prompt and appropriate treatment will recover useful vision.

A multicentre prospective study of post-traumatic endophthalmitis

PURPOSE

Study the clinical and microbiological characteristics and the prognostic factors of post-traumatic endophthalmitis.

METHODS

Seventeen eyes were included between 2004 and 2010, with clinical and microbiological data collected prospectively. Conventional cultures and panbacterial PCR were performed on aqueous and vitreous samples.

RESULTS

Clinical signs of endophthalmitis were observed soon after trauma (1.5 ± 2.5 days). Laceration with an intraocular foreign body (IOFB) was noted in 53% of the patients. At admission, all patients had aqueous humour (71%) and/or vitreous (53%) samples. Fifteen patients (88%) underwent a pars plana vitrectomy. Bacteria were identified in 77% of the cases: Staphylococcus epidermidis (n = 5), Streptococcus (n = 4), Bacillus (n = 2), Pseudomonas stuzeri (n = 1), and Streptococcus salivarius and Gemella haemolysans (multibacterial infection, n = 1). Progression toward phthisis was observed in 35% of the cases; 41% of the patients recuperated visual acuity (VA) ≥20/40. A good final visual prognosis (≥20/40) was significantly associated with initial VA better than light perception (0% versus 70%, p = 0.01) and absence of pupillary fibrin membrane (80% versus 20%, p = 0.05). There was no correlation between visual prognosis and age, the type of laceration (corneal or scleral) or presence of an IOFB. We found a statistical trend toward an association between bacterial virulence and poor final VA.

CONCLUSION

This series showed that better final VA outcomes were associated with initial VA better than light perception, S. epidermidis or culture-negative cases and absence of retinal detachment during the clinical course.

Polymicrobial endophthalmitis: prevalence, causative organisms, and visual outcomes

BACKGROUND

The purpose of the present study is to evaluate the prevalence, causative organisms, and visual acuity outcome in patients with culture-proven polymicrobial endophthalmitis. The method used in this study is the non-comparative, consecutive case series using a retrospective analysis of patients diagnosed with polymicrobial endophthalmitis for the period 2000 to 2010.

RESULTS

Polymicrobial endophthalmitis was identified in 43/1,107 (3.88%) patients. Forty-two patients had two isolates, and one patient had grown three isolates, yielding a total of 87 isolates. Gram-positive cocci were the most common isolate (n = 53; 60.9%) including Staphylococcus epidermidis (n = 14/53; 16.1%) and Streptococcus pneumoniae (n = 13/53; 13.8%). The etiologies included posttraumatic (n = 31/43; 72.1%) and postoperative (n = 9/43; 20.9%) endophthalmitis. Antibiotic susceptibilities among Gram-positive bacteria were vancomycin (100%) and chloramphenicol (96%). Susceptibilities among Gram-negative bacteria were ciprofloxacin (86.4%) and ofloxacin (81.2%). A maximum number of secondary interventions were done in traumatic cases (38.7%) and cases having coinfection with Gram-negative bacteria and fungus (66.7%). Visual acuity (VA) < 20/200 was more frequently observed in posttraumatic cases (n = 27/31; 87.1%) as compared with postoperative cases (n = 4/9; 44.4%). Of the 43 patients, only 9 patients (20.9%) achieved a VA ≥ 20/200 on final follow-up. Four out of twelve patients (33.3%), with fungus as one of the isolates, had a VA ≥ 20/200.

CONCLUSIONS

Although polymicrobial infection in endophthalmitis is uncommon, it is generally associated with poor visual acuity outcomes especially in eyes with open-globe injuries. Coinfection with Gram-negative bacteria or fungi was associated with most unfavorable visual outcome.