Microbiological Isolates and Antibiotic Susceptibilities: A 10-Year Review of Culture-Proven Endophthalmitis Cases

Pediatric Endophthalmitis Over the Last Five Decades: A Case Report and Systematic Review

INTRODUCTION

Pediatric infectious endophthalmitis is a rare, severe ocular infection that can have devastating consequences. It may be exogenous or endogenous, with exogenous endophthalmitis being more common. Current data on the etiology, microbiology, antibiotic treatments and outcomes in pediatric cases is limited.

PURPOSE

To summarize the etiology, microbiology, visual outcomes and management of pediatric endophthalmitis.

METHODS

A literature review was conducted on cases of pediatric endophthalmitis published from 1980 to 2022, identified through searches of PubMed, Medline, Web of Science and Google Scholar databases.

RESULTS

A total of 796 patients were included. Ocular trauma was the most common cause with 623 patients (78.3%), followed by posteye surgery with 100 patients (12.6%) and endogenous endophthalmitis with 67 patients (70 eyes) (8.4%). Among culture-positive cases, gram-positive microorganisms predominated. Treatment involved pars plana vitrectomy in 608 patients (76%) and intraocular antibiotics in 590 patients (74%). Favorable visual acuity (≥20/200) was achieved in 30.5% of patients, 20% had no light perception and 12.5% developed poor anatomical outcomes with phthisis bulbi.

CONCLUSION

Our review provides insights into the etiology, epidemiology, microbiology, treatment and visual outcomes of pediatric endophthalmitis based on available literature worldwide.

POSTINTRAVITREAL INJECTION AND POSTCATARACT EXTRACTION ENDOPHTHALMITIS VISUAL OUTCOMES BY ORGANISM: A SYSTEMATIC REVIEW AND META-ANALYSIS

PURPOSE

To compare visual outcomes of endophthalmitis following intravitreal injections (IVIs) and cataract extraction by causative organism.

METHODS

Searches in Cochrane Central Register of Controlled Trials, MEDLINE, and Embase identified articles reporting visual outcomes by causative organisms in post-IVI and cataract extraction endophthalmitis cases from January 2010 to February 2022. A random-effects meta-analysis compared visual improvement among endophthalmitis cases caused by causative organisms.

RESULTS

Eighty-five out of 3,317 retrieved studies were included. The highest degree of visual acuity improvement in both post-IVI and postcataract extraction endophthalmitis was seen in cases caused by coagulase-negative staphylococci, followed by gram-negative organisms and other gram-positive organisms such as streptococci and enterococci. Culture-negative cases showed more visual acuity improvement than culture-positive cases in post-IVI endophthalmitis. These results remained consistent when accounting for endophthalmitis treatment, IVI type, condition requiring IVI treatment, follow-up period, and initial preprocedural visual acuity.

CONCLUSION

Coagulase-negative staphylococci and gram-negative organisms show the most visual acuity improvement in both post-IVI and postcataract extraction endophthalmitis. Other gram-positive organisms such as streptococci and enterococci are associated with less visual improvement. This updated systematic review and meta-analysis revealed that the results of the Endophthalmitis Vitrectomy Study are consistent decades later despite advancements in surgical practices and the evolution of microorganisms over time.

EXAMINATION OF GALACTOMANNAN LEVELS IN INTRAOCULAR FLUID TO ASSIST THE DIAGNOSIS OF ASPERGILLUS ENDOPHTHALMITIS

PURPOSE

To evaluate the utility of galactomannan testing of intraocular fluid in the diagnosis of Aspergillus endophthalmitis (AE).

METHODS

This retrospective study enrolled three groups of patients, including those with 17 eyes with AE; 20 eyes with intraocular infection of bacteria, viruses, or other fungi; and 19 eyes with cataract. Intraocular fluid from all these patients was collected for galactomannan testing. In addition, the receiver operating characteristic curves and diagnostic significance were analyzed.

RESULTS

The mean optical density index (ODI) of galactomannan was 5.77 ± 1.73 in the AE group, which was significantly higher than that in the non- Aspergillus intraocular infection group (0.19 ± 0.11, P < 0.001) and the negative control group (0.29 ± 0.27, P < 0.001). The area under the receiver operating characteristic curve (area under the curve) was 1.00 (95% confidence interval, 1.00-1.00; P < 0.001) in the AE group and the other two groups. At a cutoff optical density index of 1.88, the sensitivity and specificity were 100.0% and 100.0%, respectively, and the Youden index reached its highest value of 1.00.

CONCLUSION

Galactomannan testing of intraocular fluid indicated good sensitivity and specificity for the diagnosis of AE, thereby promising a rapid diagnostic modality for AE.

Susceptibility of Ocular Surface Bacteria to Various Antibiotic Agents in a Romanian Ophthalmology Clinic

Periodic assessment of bacterial contamination is necessary as it allows proper guidance in cases of eye infections through the use of appropriate antibiotics. Due to the extensive use of antibiotic treatment, many strains of the microbiota that cause infections are resistant to the usual ophthalmic antibiotics. The present study provides an updated assessment of the susceptibility of Gram-positive and Gram-negative bacteria found on the ocular surface to the most commonly used antibiotic agents in patients undergoing cataract surgery. A total of 993 patients were included in the study with ages between 44 and 98 years old. Conjunctival cultures were collected 7 days before cataract surgery. The response of Gram-positive and Gram-negative bacteria to various antibiotic classes, such as glycopeptides, cephalosporins, carbapenems, fluoroquinolones, aminoglycosides, phenicols, tetracyclines, rifamycins, macrolides and penicillins, was assessed. From the tested antibiotics, vancomycin had 97.8% efficacy on Gram-positive bacteria. In the cephalosporin category, we observed a high level of resistance of the cefuroxime for both Gram-positive and negative bacteria. Antibiotics that have more than 90% efficacy on Gram-positive bacteria are meropenem, imipenem, netilmicin, amikacin and rifampicin. On Gram-negative bacteria, we found 100% efficacy of all tested fluoroquinolones, i.e., aminoglycosides (except for tobramycin), doxycycline, azithromycin, clarithromycin and chloramphenicol. The current study illustrates patterns of increased resistance in certain bacteria present on the ocular surface to some of the commonly used antibiotics in ophthalmological clinical practice. One such revealing example is cefuroxime, which has been highly used as an intracameral antibiotic for the prevention of bacterial endophthalmitis after cataract surgery.

Microbiological Characteristics and Risk Factors Involved in Progression from Fungal Keratitis with Hypopyon to Keratitis-Related Endophthalmitis

PURPOSE

To investigate the differences in microbiological characteristics, risk factors, drug resistance, and visual outcomes in three infections: fungal keratitis with hypopyon (FKH), keratitis-related fungal endophthalmitis (FKE), and fungal endophthalmitis without keratitis (FE).

METHODS

An analytical cross-sectional study.

RESULTS

In total, 14.57% of eyes with FKH progressed to endophthalmitis. Hypopyon, pre-existence of lens problems, topical steroid use and sever keratitis were significantly associated with the development of FKE. The risk factors of the FKH and FE group were mainly plant trauma and open globe trauma, respectively. Keratitis-related endophthalmitis (FKE) showed a significantly higher resistance than the other two groups. The FKH group had the best final visual acuity, while the FKE group had the worst.

CONCLUSION

Hypopyon height, pre-existing lens problems, topical steroid use and sever keratitis are risk factors for progression to endophthalmitis in eyes with fungal keratitis, and its progression is not affected by a single fungus. The antifungal drugs resistance in patients with endophthalmitis related to keratitis was significantly higher than that associated with other reasons. Timely diagnosis and risk factor assessment are essential for ensuring early treatment of FKE.

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.

Formulation development and in Vitro-Ex vivo characterization of hot-melt extruded ciprofloxacin hydrochloride inserts for ocular applications: Part I

This study developed, optimized, characterized, and evaluated bioadhesive, hot-melt extruded (HME), extended-release ocular inserts containing ciprofloxacin hydrochloride (CIP-HCL) to improve the therapeutic outcomes of ocular bacterial infections. The inserts were fabricated with FDA-approved biocompatible, biodegradable, and bioadhesive polymers that were tuned in different ratios to achieve a sustained release profile. The results revealed an inverse relationship between the Klucel™ hydroxypropyl cellulose (HPC, 140,000 Da) concentration and drug release and extended-release profile over 24 h. The CIP-HCL-HME inserts presented stable drug content, thermal behavior, surface pH, and release profiles over three months of room-temperature storage and demonstrated adequate mucoadhesive strength. SEM micrographs revealed a smooth surface. Bacterial growth was not observed on the samples during the in vitro release experiment (0.5-24 h), indicating that a minimum inhibitory concentration (MIC) of 90 against Pseudomonas aeruginosa was achieved. Ex vivo transcorneal permeation studies using excised rabbit corneas revealed that the prepared ocular inserts prolonged the transcorneal flux of the drug compared to commercial eye drops and immediate-release inserts and could reduce the administration frequency to once daily. Therefore, the inserts could increase patient compliance and exhibited prolonged antibacterial activity and thus could provide better therapeutic outcomes against ocular bacterial infections.

Ten-Year Analysis of Pathogenic Factors and Etiological Characteristics of Endophthalmitis from a Tertiary Eye Center in North China

Purpose

To describe the etiology and spectrum of isolated pathogens in endophthalmitis over 10 years from an ophthalmic hospital in North China and report their antimicrobial susceptibilities.

Patients and Methods

The data covered the patients with endophthalmitis treated at Qingdao Eye Hospital from January 2011 to December 2020. Patients’ medical history, pathogenic factors, bacterial and fungal culture results of intraocular specimens, and in vitro drug sensitivity test results were assessed.

Results

A total of 524 cases were counted in this study. Exogenous endophthalmitis was the main component, accounting for 94.66%, of which 49.62% of eyes had a history of ophthalmic trauma, intraocular surgery in 26.72% and suppurative keratitis in 17.37%. By comparison, endogenous endophthalmitis was found in only 5.34% of eyes. Among the 292 strains of pathogenic organisms obtained by co-culture, gram-positive bacteria accounted for 64.04%, with Staphylococcus epidermidis as the predominant pathogen (29.45%). Gram-positive cocci were identified in 76.77% of eyes with traumatic endophthalmitis, while 53.70% of keratitis-associated endophthalmitis was caused by fungi. The high susceptibility of bacteria to vancomycin (77.78%~98.33%) supported its continued use as empirical treatment. Among the fluoroquinolones, gram-positive cocci showed a higher susceptibility to gatifloxacin (94.83%), while there was a significant decrease to levofloxacin (51.67%). Gram-negative bacteria were less sensitive to cephalosporins (45.95%~66.67%) than fluoroquinolones (68.42%~78.05%) and aminoglycosides (75.00%~78.05%). Fungal susceptibilities to voriconazole and amphotericin B were 90.16% and 70.31% respectively. More than half of the 11 antibiotics were observed to exhibit a trend of reduced susceptibility.

Conclusion

Ophthalmic trauma was the primary pathogenic factor of endophthalmitis. Gram-positive cocci were the most common pathogens of traumatic and postoperative endophthalmitis, while suppurative keratitis-associated endophthalmitis often resulted from fungal pathogens. Levofloxacin as the preferred antibiotic in the perioperative period and cephalosporin as the first-line drug for the treatment of empiric endophthalmitis need to be vigilant.

Endophthalmitis panorama in the Jerusalem area

PURPOSE

The spectrum of microbial infections and the pattern of their susceptibility are variable among communities. Researching these data will lead to the establishment of the most appropriate national management strategies. The purpose of this study was to analyze the epidemiological, clinical, microbial spectrum and antibiotic susceptibility of endophthalmitis cases in a tertiary referral center in Jerusalem.

METHODS

Retrospective review of medical charts of patients presenting with endophthalmitis over a 12-year period.

RESULTS

A total of 74 eyes of 70 patients (males 56%) were included. Mean age ± SD at presentation was 60 ± 19.5 years. Exogenous endophthalmitis accounted for 78% of cases, of which 62% followed an intraocular surgery, 21% occurred after intravitreal injections, 10% followed infectious keratitis and 7% were posttraumatic. Endogenous cases were predominantly observed in diabetic patients. Microbial isolates were identified in 44 samples. Of them, gram-positive bacteria were the predominant microorganisms detected in 33 samples (75%); Staphylococcus epidermidis and Enterococcus faecalis were the most commonly detected pathogens. Mean presenting ± SD LogMAR visual acuity (VA) was 2.38 ± 1.21 and it improved at last follow-up to 1.7 ± 1.37 (p = 0.004, paired t test). Cases secondary to gram-positive microbes were associated with improved VA during the follow-up while cases secondary to gram-negative microbes was correlated with poor final VA (p = 0.046, r² = 0.4). There was no evidence of bacterial resistance in the antibiograms for either vancomycin, ceftazidime, ceftriaxone or amikacin.

CONCLUSIONS

Intraocular surgery remains the most common event preceding endophthalmitis with coagulase-negative staphylococci being the most frequently detected microorganisms. The microbial spectrum of endophthalmitis is similar to that in the western world.

In vitro study examining the effectiveness of antiseptic prophylaxis for antibiotic-resistant bacterial endophthalmitis

PURPOSE

To assess the effectiveness of current antiseptic agents on multidrug-resistant (MDR) isolates in an in vitro setting.

SETTING

Department of Microbiology, The National Maternity Hospital, Dublin, Ireland.

DESIGN

Organisms were selected based on current review of endophthalmitis literature: methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE), Pseudomonas aeruginosa, carbapenem-resistant and extended-spectrum β-lactamase Klebsiella pneumoniae, and vancomycin-resistant (VRE) Enterococcus faecalis.

METHODS

Samples were exposed to povidone-iodine (PVI) 5% and chlorhexidine (CHX) 0.05% for 0.5 minutes, 1 minute, 3 minutes, and 5 minutes. After inactivation, organisms were incubated under standard conditions and growth assessed after 16 hours.

RESULTS

MRSA and MRSE responded to 3-minute PVI exposure. CHX eradicated MRSA growth after 5 minutes but failed to completely suppress MRSE. Pseudomonas and Klebsiella required 3-minute CHX exposure and 5-minute PVI exposure for complete clearance. Eradication of enterococci (VRE positive and negative) was not achieved at 10 minutes of CHX or PVI exposure. Comparison of PVI vs CHX showed a benefit for PVI in MRSA (P < .01) and MRSE (P < .001) eradication at 3 minutes.

CONCLUSIONS

Current recommendations of 3 minutes of antisepsis prior to intraocular surgery are not sufficient for complete eradication of MDR organisms from the ocular surface. A bespoke approach is suggested to patients at risk for carriage of MDR organisms to minimize the risk of endophthalmitis.

Distribution and risk factors of postoperative endophthalmitis in people with diabetes

Purpose

To evaluate (i) the distribution of postoperative endophthalmitis (POE) in patients who underwent cataract surgery, (ii) risk factors in diabetic versus nondiabetic patients, and (iii) distribution of POE in those who had undergone rapid reduction of preoperative blood sugar levels versus those with normal blood sugar levels.

Methods

Medical records were reviewed from January 1995 to July 2021. In total, 391 eyes of 391 patients who developed POE after cataract surgery were studied. Patients with POE were divided into Group A, patients with diabetes (n = 128), and Group B, patients without diabetes (n = 263), and the associations of various clinical factors in the two groups were studied. Patients with diabetes with raised random blood sugars (RBS) preoperatively were subjected to a rapid reduction of blood sugar (RBS <200 mg%) to be considered eligible for surgery. Microbiological profile of patients was examined.

Results

The cumulative incidence of POE over 26 years was 0.09%. Those who underwent a rapid reduction in preoperative blood sugar levels had higher rates of POE (53.1%) compared with (46.9%) those with blood sugar levels under control (P = 0.486). Men with diabetes had 1.634 times higher odds of POE (P = 0.048), and those with diabetes and hypertension had 3.961 times greater odds of having POE (P < 0.001) when adjusted for age, alcohol, smoking, and socioeconomic strata and presence of posterior capsule rupture. Positive culture results were observed in 45/128 (35%) patients with diabetes and 71/263 (27%) patients without diabetes. Staphylococcus epidermidis was the most commonly identified organism and was detected in 10/45 (22%) in those with diabetes and 21/71 (29%) in those without diabetes of all the culture-positive cases.

Conclusion

In patients with POE, the odds are greater for men with diabetes, those with a history of hypertension, as well as those who undergo a rapid reduction of preoperative blood sugar.

Comparison of causative microorganisms of posttraumatic endophthalmitis with and without retained intraocular foreign bodies

Background

The goals of this work were to report the demographic characteristics of patients with clinically diagnosed endophthalmitis with or without intraocular foreign bodies (IOFBs) and to analyze the causative microorganisms.

Methods

A retrospective analysis was conducted on 1257 patients with clinically diagnosed posttraumatic endophthalmitis who were admitted to Zhongshan Ophthalmic Center between January 1, 2013, and August 31, 2020.

Results

Of the 1257 patients with clinically diagnosed posttraumatic endophthalmitis, 452 (36.0%) patients had IOFBs. Male dominance was more common among the patients with IOFBs than the patients without IOFBs. The average age of the patients with IOFBs was older than that of the patients without IOFBs. The most common microbial pathogens in these two groups were Gram-positive cocci and Gram-negative bacilli. Gram-positive bacilli were more common in the patients with IOFBs than in those without IOFBs (17.9 vs. 9.4%), and Bacillus spp. accounted for 12.6 and 5.5%, respectively. Fungi were less abundant in the patients with IOFBs than in those without IOFBs (8.0 vs. 15.6%).

Conclusions

Patients with IOFBs were mostly male and older than those without IOFBs. Gram-positive bacilli were more common and fungi were less common in patients with IOFBs than in those without IOFBs.

Microbial Spectrum and Resistance Patterns in Ocular Infections: A 15-Year Review in East China

Purpose

To report antibiotic resistance rates and trends of common ocular isolates collected over a 15-year period.

Methods

We collected 3533 isolates from July 1, 2005 to July 31, 2020. Antibiotic sensitivity was determined according to the guidelines of the Clinical and Laboratory Standards Institute. Chi-squared (χ²) test was used to analyze changes in antibiotic susceptibility over 15 years.

Results

Among the 3533 isolates, the predominant pathogens were the staphylococcal species. Methicillin resistance was observed in 381 Staphylococcus aureus (S. aureus) isolates (46.4%) and 1888 coagulase-negative staphylococci (CoNS) isolates (61.1%), and methicillin-resistant (MR) isolates had a high probability of concurrent resistance to fluoroquinolones and aminoglycosides. The mean percentage of resistance in staphylococcal isolates did not reach statistical significance across patient age groups (P = 0.87). Methicillin resistance did not increase in the CoNS (P = 0.546) isolates, and resistance to methicillin slightly decreased among S. aureus (P = 0.04) isolates over 15 years. Additional exploratory analysis revealed a small decrease in resistance to tobramycin (P = 0.01) and chloramphenicol (P < 0.001) among the CoNS isolates. All staphylococcal isolates were susceptible to vancomycin.

Conclusion

Staphylococci were the most common microorganisms responsible for causing ocular infections. Antibiotic resistance was high among staphylococci, with nearly half of these isolates were resistant to methicillin and these had a high probability of concurrent resistance among MR staphylococci to other antibiotics. Overall, ocular resistance did not significantly change during the 15-year study period. We conclude that continued surveillance of antibiotic resistance provides critical data to guide antibiotic selection.

Antimicrobial resistance of ocular microbes and the role of antimicrobial peptides

Isolation of antimicrobial-resistant microbes from ocular infections may be becoming more frequent. Infections caused by these microbes can be difficult to treat and lead to poor outcomes. However, new therapies are being developed which may help improve clinical outcomes. This review examines recent reports on the isolation of antibiotic-resistant microbes from ocular infections. In addition, an overview of the development of some new antibiotic therapies is given. The recent literature regarding antibiotic use and resistance, isolation of antibiotic-resistant microbes from ocular infections and the development of potential new antibiotics that can be used to treat these infections was reviewed. Ocular microbial infections are a global public health issue as they can result in vision loss which compromises quality of life. Approximately 70 per cent of ocular infections are caused by bacteria including Chlamydia trachomatis, Staphylococcus aureus, and Pseudomonas aeruginosa and fungi such as Candida albicans, Aspergillus spp. and Fusarium spp. Resistance to first-line antibiotics such as fluoroquinolones and azoles has increased, with resistance of S. aureus isolates from the USA to fluoroquinolones reaching 32 per cent of isolates and 35 per cent being methicillin-resistant (MRSA). Lower levels of MRSA (seven per cent) were isolated by an Australian study. Antimicrobial peptides, which are broad-spectrum alternatives to antibiotics, have been tested as possible new drugs. Several have shown promise in animal models of keratitis, especially treating P. aeruginosa, S. aureus or C. albicans infections. Reports of increasing resistance of ocular isolates to mainstay antibiotics are a concern, and there is evidence that for ocular surface disease this resistance translates into worse clinical outcomes. New antibiotics are being developed, but not by large pharmaceutical companies and mostly in university research laboratories and smaller biotech companies. Antimicrobial peptides show promise in treating keratitis.

Posttraumatic Bacillus cereus Endophthalmitis: Clinical Characteristics and Antibiotic Susceptibilities

Purpose

To report the clinical characteristics, antibiotic susceptibilities, and visual outcomes of patients with posttraumatic endophthalmitis caused by Bacillus cereus.

Methods

In this retrospective, noncomparative case series, the medical records of eyes with culture-proven Bacillus cereus endophthalmitis treated from January 2016 to December 2019 at a referral center were reviewed. Clinical features, antibiotic susceptibilities, and visual outcomes were assessed.

Results

A total of 19 eyes of 19 patients were identified. Three patients progressed to orbital cellulitis. Vitrectomy was performed in 13 eyes, and 11 required silicone oil tamponade. Finally, seven eyes underwent silicone oil removal surgery during follow-up. Only two patients retained a visual acuity better than FC. Four patients underwent evisceration, and three patients had NLP. The cultured Bacillus cereus was sensitive to levofloxacin, ofloxacin, tobramycin, and neomycin at 100%.

Conclusions

The visual outcomes of posttraumatic Bacillus cereus endophthalmitis were generally poor regardless of the prophylactic and therapeutic measures administered. Vitrectomy combined with silicone oil tamponade could help to save the eyeball. Bacillus cereus has a good susceptibility to ofloxacin, levofloxacin, tobramycin, and neomycin; therefore, fluoroquinolones and aminoglycosides can be used to treat Bacillus cereus infection.

Design of Topical Ocular Ciprofloxacin Nanoemulsion for the Management of Bacterial Keratitis

Bacterial keratitis (BK) is a critical ocular infection that can lead to serious visual disability. Ciprofloxacin (CIP), moxifloxacin (MOX), and levofloxacin (LFX) have been accepted as monotherapies by the US Food and Drug Administration for BK treatment. CIP is available commercially at 0.3% w/v concentration as an ophthalmic solution and as an ointment for ocular delivery. Because of solubility issues at physiological pH, CIP precipitation can occur at the corneal surface post instillation of the solution dosage form. Consequently, the ocular bioavailability of CIP is reduced. The ointment dosage form is associated with side effects such as blurred vision, itching, redness, eye discomfort, and eye dryness. This study aimed to design a CIP loaded nanoemulsion (NE; CIP-NE) to facilitate drug penetration into the corneal layers for improved therapeutic outcomes as well as to overcome the drawbacks of the current commercial ophthalmic formulations. CIP-NE formulations were prepared by hot homogenization and ultrasonication, using oleic acid (CIP-O-NE) and Labrafac® Lipophile WL 1349 (CIP-L-NE) as the oily phase, and Tween® 80 and Poloxamer 188 as surfactants. Optimized CIP-NE was further evaluated with respect to in vitro release, ex vivo transcorneal permeation, and moist heat sterilization process, using commercial CIP ophthalmic solution as a control. Optimized CIP-O-NE formulation showed a globule size, polydispersity index, and zeta potential of 121.6 ± 1.5 nm, 0.13 ± 0.01, and -35.1 ± 2.1 mV, respectively, with 100.1 ± 2.0% drug content and was spherical in shape. In vitro release and ex vivo transcorneal permeation studies exhibited sustained release and a 2.1-fold permeation enhancement, respectively, compared with commercial CIP ophthalmic solution. Autoclaved CIP-O-NE formulation was found to be stable for one month (last time-point tested) at refrigerated and room temperature. Therefore, CIP-NE formulation could serve as an effective delivery system for CIP and could improve treatment outcomes in BK.

Vitrectomy combined with intravitreal antifungal therapy for posttraumatic fungal endophthalmitis in eastern China

Background

To evaluate the effect and prognostic factors of vitrectomy combined with intravitreal antifungal therapy for posttraumatic fungal endophthalmitis in Eastern China.

Methods

We retrospectively reviewed the medical records of patients who developed fungal endophthalmitis after penetrating ocular trauma at an ophthalmic center in Eastern China. All patients underwent vitrectomy and intravitreal injection of antifungal drugs.

Results

Thirty-five patients (35 eyes) were included. Twelve eyes suffered plant trauma, 17 eyes metal trauma, and 6 eyes other trauma. The culture results for all 35 eyes showed filamentous fungi, including Aspergillus in 26 eyes (74.3%). Twenty-three eyes underwent vitrectomy once and 12 eyes were treated twice. Four eyes were iridectomized because of a fungal lesion behind the iris. Fungal endophthalmitis was effectively controlled in 33 eyes (94.3%), whereas 2 eyes were ultimately enucleated. Visual acuity was significantly better after treatment than before treatment (P = 0.0006). According to the preoperative vision, the affected eyes were divided into two groups: group 1A (light perception) and group 1B (better than light perception). The final visual acuity in group 1B was significantly better than that in group 1A (P = 0.0289).

Conclusions

Vitrectomy combined with intravitreal antifungal therapy is an effective treatment for posttraumatic fungal endophthalmitis. Preoperative visual acuity is a significant factor affecting the prognosis of visual acuity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-020-01703-7.

Characterization of Pseudomonas aeruginosa isolates from patients with endophthalmitis using conventional microbiologic techniques and whole genome sequencing

Purpose

To demonstrate antibiotic susceptibility and genomic virulence factor profiles of Pseudomonas aeruginosa isolates from patients with culture-confirmed endophthalmitis.

Methods

Clinical isolates from patients diagnosed with pseudomonas endophthalmitis were included. Laboratory antibiotic susceptibility testing and whole genome sequencing was performed on all isolates.

Results

In the current study, 8 patients had vitreous culture-confirmed endophthalmitis due to P. aeruginosa. All isolates were multi-drug resistant but sensitive to ceftazidime and each fluoroquinolone tested. Whole genome sequencing revealed a total of 179 unique genes. The most common type of virulence genes included those involved in adherence and the secretion system. Seven of 8 (88%) isolates were of the cytoinvasive phenotype (exoST) and no isolates contained exoU.

Conclusions

P. aeruginosa associated endophthalmitis is often multi-drug resistant and demonstrates a variety of virulence factors with those involved in adherence and the secretion system being the most common.

Etiology, microbiological isolates, and antibiotic susceptibilities in culture-proven pediatric endophthalmitis: a 9-year review

Purpose

To analyze the etiology, microbiological isolates, and antibiotic susceptibilities of endophthalmitis in pediatric patients.

Methods

Patients aged < 18 years with culture-positive endophthalmitis in Zhongshan Ophthalmic Center between January 2010 and December 2018 were included retrospectively.

Results

A total of 127 patients (127 eyes) were included, and 108 (85%) had posttraumatic endophthalmitis. Streptococcus (21.4%), coagulase-negative Staphylococcus (14.5%), Aspergillus (6.9%), and Bacillus cereus (5.3%) were the common organisms. The proportion of Streptococcus decreased with age (40.0% in 0–3 years, 16.3% in 4–12 years, and 6.3% in 13–17 years), while coagulase-negative Staphylococcus increased from 5.7% to 18.8%. Overall, fluoroquinolones achieved the highest antibiotic susceptibility rate (> 95%), while the susceptibility of isolated bacteria to tobramycin and cefazolin was only 60.2% and 59.4%, respectively. The susceptibility rates of Gram-positive cocci to cephalosporins were nearly 90%. For Gram-negative bacilli, susceptibility to neomycin was 91.3%.

Conclusion

Trauma was the main etiology for pediatric endophthalmitis. Although Streptococcus was the most prevalent organism in general, the dominant pathogen varied with age, which merits clinical attention. Fluoroquinolones showed the highest antibiotic efficacy; however, commonly used antibiotics tobramycin and cefazolin showed relatively low antibiotic susceptibility. Thus, antibiotic resistance in pediatric populations merits clinical attention.

Ciprofloxacin Loaded Nanostructured Lipid Carriers Incorporated into In-Situ Gels to Improve Management of Bacterial Endophthalmitis

Bacterial endophthalmitis (BE) is a potentially sight-threatening inflammatory reaction of the intraocular fluids or tissues caused by bacteria. Ciprofloxacin (CIP) eye drops are prescribed as first-line therapy in BE. However, frequent administration is necessary due to precorneal loss and poor ocular bioavailability. The objective of the current research was to prepare CIP containing nanostructured lipid carriers (CIP-NLCs) loaded an in situ gel system (CIP-NLC-IG) for topical ocular administration for enhanced and sustained antibacterial activity in BE treatment. CIP-NLCs were prepared by the hot homogenization method and optimized based on physicochemical characteristics and physical stability. The optimized CIP-NLC formulation was converted into CIP-NLC-IG with the addition of gellan gum as a gelling agent. Furthermore, optimized CIP-NLC and CIP-NLC-IG were evaluated for in vitro release and ex vivo transcorneal permeation studies, using commercial CIP ophthalmic solution (CIP-C) as the control. The optimized CIP-NLC formulation showed particle size, polydispersity index, zeta potential, assay and entrapment efficiency of 193.1 ± 5.1 nm, 0.43 ± 0.01, -32.5 ± 1.5 mV, 99.5 ± 5.5 and 96.3 ± 2.5%, respectively. CIP-NLC-IG with 0.2% w/v gellan gum showed optimal viscoelastic characteristics. The in vitro release studies demonstrated sustained release of CIP from CIP-NLC and CIP-NLC-IG formulations over a 24 h period. Transcorneal flux and permeability increased 4 and 3.5-fold, and 2.2 and 1.9-fold from CIP-NLC and CIP-NLC-IG formulations, respectively, when compared to CIP-C. The results demonstrate that CIP-NLC-IG could be considered as an alternate delivery system to prolong the residence time on the ocular surface after topical administration. Thus, the current CIP ophthalmic formulations may exhibit improved ocular bioavailability and prolonged antibacterial activity, which may improve therapeutic outcomes in the treatment of BE.

Microbiological Isolates and Antibiotic Susceptibilities in Cases of Posttraumatic Endophthalmitis: A 15-Year Review

Purpose

The objective of this study was to evaluate the microbiological spectrum and antibiotic susceptibilities of isolates in posttraumatic endophthalmitis over a 15-year period.

Methods

A retrospective study of 3,163 posttraumatic endophthalmitis cases was conducted between July 2004 and July 2019. The outcome measures included the microbiological spectrum and antibiotic susceptibilities. Chi-squared tests were conducted to detect trends in changes in antibiotic sensitivity over the 15-year period. P values of <0.05 were considered statistically significant.

Results

Of the 3,163 cases of posttraumatic endophthalmitis, 1,003 culture-positive isolates were identified. Among these, there were 848 (84.5%) Gram-positive isolates, 109 (10.9%) Gram-negative isolates, and 46 (4.6%) fungal isolates. The most common isolates were Staphylococcal species. There was a significant increase in the percentage of fungal isolates over the 15-year period (P=0.02). Gram-positive organisms showed the greatest level of susceptibility to vancomycin (99.6%). The susceptibilities of the 109 Gram-negative isolated organisms were as follows: levofloxacin (95.8%), meropenem (95.7%), ciprofloxacin (93.5%), tobramycin (90.8%), imipenem (88.9%), trimethoprim-sulfamethoxazole (TMP-SMX) (87.7%), ertapenem (80%), and ceftazidime (79.1%). The susceptibility of Gram-positive organisms to several antibiotics, including levofloxacin (P=0.004), ciprofloxacin (P < 0.001), and chloramphenicol (P=0.001) decreased over time, whereas the susceptibility to TMP-SMX increased over time (P < 0.001). The susceptibility of Gram-negative bacilli to ceftazidime decreased over time (P=0.03).

Conclusions

Over the 15-year study period, most isolates were Gram-positive cocci, especially coagulase-negative staphylococci (CNS). Vancomycin seemed to be the most effective antibiotic for Gram-positive bacteria. Gram-negative bacteria appeared to be most susceptible to fluoroquinolones. A number of antibiotics showed an increasing trend of microbial resistance.

Gram-negative endophthalmitis: A prospective study examining the microbiology, clinical associations and visual outcomes following infection

IMPORTANCE

This is the largest Gram-negative endophthalmitis specific series and provides important evidence to guide management.

BACKGROUND

Endophthalmitis is a sight-threatening emergency. Gram-negative infections are associated with poorer visual outcomes; however, there is limited literature pertaining to this uncommon condition.

DESIGN

Prospective case series.

PARTICIPANTS

All patients presenting with endophthalmitis to a tertiary institution over a 20-year period.

METHODS

Data were collected prospectively and entered into a registry. Patients with microbiological evidence of Gram-negative infection were included in the analysis.

MAIN OUTCOMES MEASURES

Final visual acuity (VA), precipitating events, causative organisms, antibiotic sensitivity profiles and risk factors for poor visual outcomes were reported.

RESULTS

One hundred Gram-negative organisms were isolated in 97 eyes. Final VA was worse than 6/60 in 65 (67.0%) eyes at follow-up and 29 (29.9%) eyes were eviscerated or enucleated. Microbial keratitis (26.8%, n = 26) and Pseudomonas aeruginosa (34.0%, n = 34) were the most common precipitating event and causative organism, respectively. Eight (8.0%) isolates were third-generation cephalosporin resistant; of which, 7 (88.0%) were sensitive to ciprofloxacin. Preceding microbial keratitis (OR = 13.16, P = .015) or P. aeruginosa infections (OR = 3.40, P = .045) were strongly associated with poorer visual outcomes (worse than 6/60).

CONCLUSIONS AND RELEVANCE

Visual outcomes following Gram-negative endophthalmitis are extremely poor, with almost 30% of patients being eviscerated or enucleated. A majority of ceftazidime resistant organisms are sensitive to ciprofloxacin, providing evidence to support the empirical use of quinolones. Clinicians should be mindful that infections secondary to P. aeruginosa or microbial keratitis carry a particularly poor prognosis.

In vitro Susceptibilities of Methicillin-Susceptible and Resistant Staphylococci to Traditional Antibiotics Compared to a Novel Fluoroquinolone

Background

To assess the in-vitro efficacy of delafloxacin, a new fourth generation fluoroquinolone, against Staphylococcus vitreous isolates from patients with clinically diagnosed endophthalmitis. This is the first investigation of delafloxacin in ocular tissues.

Methods

Intravitreal isolates of culture-proven S. aureus and S. epidermidis were identified between 2014 and 2018. Minimum inhibitor concentrations (MIC) were determined using ETEST strips. The antibiotic susceptibilities were tested against a panel of drugs including glycopeptides such as vancomycin, as well as traditional and newer fluoroquinolones (levofloxacin, moxifloxacin, and delafloxacin).

Results

Of 45 total isolates identified between 2014 and 2018, 13% (6) were methicillin-resistant S. aureus (MRSA), 9% (4) were methicillin-sensitive S. aureus (MSSA), 53% (24) were methicillin-resistant S. epidermidis (MRSE), and 24% (11) were methicillin-sensitive S. epidermidis (MSSE). Among the fluoroquinolones, resistance rates were 61% for levofloxacin, 50% for moxifloxacin, and 12% for delafloxacin. Inter-class comparisons between delafloxacin and the two other fluoroquinolones demonstrated higher Gram-positive susceptibility to delafloxacin (p < 0.01). MIC90 values were lowest for delafloxacin (1.0 μg/mL) compared to levofloxacin (8.0 μg/mL) and moxifloxacin (8.0 μg/mL). Vancomycin was 100% effective against all isolates with MIC90 value of 0.75 μg/mL.

Conclusion

Compared to levofloxacin and moxifloxacin, the newer fluoroquinolone delafloxacin demonstrated the lowest MICs values and lowest rates of resistance for Gram-positive in-vitro S. epidermidis and S. aureus vitreous isolates.

Bacterial etiology and antimicrobial resistance trends in ocular infections: A 30-year study, Turin area, Italy

PURPOSE

Bacterial ocular infections can result in loss of all or part of the ocular structures, contributing to a high disability charge. Local surveillance of etiology and susceptibility patterns is crucial for an appropriate empiric management of ocular infections. The aim of this study was to analyze of bacterial spectrum in culture-proven ocular infections and trends of antimicrobial susceptibility patterns.

METHODS

A monocentric retrospective study was performed including ocular infection cases diagnosed at the Microbiology Unit of Turin Ophthalmic Hospital between 1988 and 2017. Spectrum of pathogens that caused bacterial culture-proven ocular infections and trends of antimicrobial susceptibility patterns were analyzed.

RESULTS

A total of 15,517 culture-positive isolates were identified as causative agents of ocular infections. Gram-positive bacteria were deemed to cause infection in 73.5% of cases. Staphylococcus spp. and Pseudomonas spp., coagulase-negative staphylococci, Staphylococcus aureus were the leading causative pathogens of keratitis, endophthalmitis, and conjunctivitis, respectively. Statistically significant changes in temporal trends were observed for all analyzed microorganism groups except for Enterobacteriaceae group. Overall, fluoroquinolones and chloramphenicol demonstrated to be the most effective antimicrobials in vitro toward bacterial ocular infections, followed by tetracycline, ampicillin, and aminoglycosides. Enterobacteriaceae isolates showed higher multi-drug resistance rate, followed by coagulase-negative staphylococci. Analysis of resistance rates over time highlighted increasing resistance trend for aminoglycosides among Gram-negative and for both aminoglycosides and fluoroquinolones among Gram-positive pathogens, especially for S. aureus.

CONCLUSION

This study provided a 30-year assessment of bacterial ocular infections in an urban area of Italy, giving support to epidemiological consciousness and guiding empiric antimicrobial therapy.

Antibiotic resistance profile in eye infections in a reference centre in Floridablanca, Colombia

BACKGROUND AND OBJECTIVE

In view of the increasing bacterial resistance to antibiotics, it is necessary to determine it locally in order to serve as a guide in clinical management. The purpose of this study was to characterise the pattern of antibiotic sensitivity in cases of eye infections in a third level ophthalmological institution in Floridablanca (Colombia).

MATERIALS AND METHODS

An observational cross-sectional study in which an analysis was made of the culture and antibiogram reports of specimens taken from cases of conjunctivitis, infectious keratitis, and endophthalmitis between January 2013 and June 2016.

RESULTS

A total of 833 specimens were positive for bacteria. Considering both gram-positive and gram-negative microorganisms gentamicin, tobramycin, and ciprofloxacin showed high resistance rates (64.4%, 40.3%, and 29.1%, respectively). Moxifloxacin, vancomycin, imipenem, and gatifloxacin showed low percentages of resistance: 2.6%, 2.1%, 0.6%, and 0.4%, respectively. When comparing the results with previous studies in our institution, there was a decrease in sensitivity to the fourth-generation quinolones and imipenem, especially within the gram-negative ones.

CONCLUSION

Fourth generation quinolones, imipenem and vancomycin continue to have a low in vitro resistance to bacteria that cause eye infections. However, there was a tendency to an increase in the resistance of gram-negative bacteria. Measures should be taken to try to control this phenomenon, and consider possible antimicrobial therapy alternatives to infections caused by these microorganisms.

Stability of a 50 mg/mL Ceftazidime Eye-Drops Formulation

Background

Microbial keratitis are severe infectionsgenerally linked to risk factors. High-doses antibiotic eye-drops could be required to avoid severe complications. In such cases, hospital pharmacists are in charge of their production given the lack of such formulations on the market. The stability of these antibiotic eye-drops is generally limited to a couple of days and publications generally do not describe addition of microbial preservatives even though it is a European Pharmacopeia requirement. The aim of this study was to describe a new ceftazidime eye-drops formulation at 50 mg/mL with a antimicrobial additive, benzalkonium chloride at 0.04 mg/mL.

Methods

Physico-chemical studies of this new formulation were performed by a stability indicating HPLC-UV method validated according to ICH standards, osmolality measurements, pH monitoring and visual examinations. Antimicrobial preservative efficacy was evaluated according to the method from the European Pharmacopeia.

Results

After 75 days at −20 °C followed by 7 days at 4 °C, or after 7 days at 4 °C, the eye-drops were stable. A degradation trend was finally observed at day 14 at 4 °C.

Conclusions

A new ceftazidime eye-drops formulation is proposed with a stability of 7 days. Outpatients do not need to return to the hospital pharmacy for repeat dispensing, thus possibly improving treatment compliance.

Diagnostic performance of blood culture bottles for vitreous culture compared to conventional microbiological cultures in patients with suspected endophthalmitis

The purpose of this investigation was to evaluate the performance of blood culture bottles in comparison to conventional microbiological culture techniques in detecting causative microorganisms of endophthalmitis and to determine their anti-infective susceptibility profiles. All consecutive cases with clinically suspected endophthalmitis in a university-based ophthalmology department between January 2009 and December 2016 were analysed in this retrospective comparative case series. Samples from 247 patients with suspected endophthalmitis underwent microbiological diagnostic work-up. All three culture methods were performed from 140 vitreous specimens. Vitreous fluid specimens were inoculated in blood culture bottles, aerobic and anaerobic broth solutions, and on solid media. Anti-infective susceptibility profiles were evaluated by semi-automated methods and/or gradient diffusion methods. Microorganisms were grown in 82 of 140 specimens for which all methods were performed (59%). Microorganisms were more frequently grown from blood culture bottles (55%) compared to broth solution (45%, p = 0.007) and solid media (33%, p < 0.0001). Considerable differences in the performance among culture media were detected for fungal pathogens. All grown fungi were detected by blood culture bottles (11 of 11, 100%). Broth solution recovered 64% and solid media 46% of grown fungi. No Gram-positive bacterium was resistant to vancomycin and all Gram-negative pathogens except for one isolate were susceptible to third-generation cephalosporins. In suspected endophthalmitis patients, blood culture bottles have a higher overall pathogen detection rate from vitreous fluid compared to conventional microbiological media, especially for fungi. The initial intravitreal antibiotic therapy with vancomycin plus third-generation cephalosporins appears to be an appropriate treatment approach for bacterial endophthalmitis.

Bacterial keratitis treated by strengthened antibiotic eye drops: An 18 months review of clinical cases and antibiotic susceptibilities

PURPOSE

To describe, in patients treated for infectious keratitis, the microorganisms identified and their antibiotic susceptibility over a period of 18 months.

METHOD

Retrospective, descriptive, non-comparative study. Medical and biological data were extracted from the patients' file treated with strengthened antibiotic eye drops at Angers University Hospital between January 2015 and June 2016. The main elements noted were the bacteria involved and their susceptibility to antibiotics. Patients' visual acuity at the start and end of treatment was compared.

RESULTS

Forty-eight patients were included. Almost one bacterium was identified in 31 patients, totalling 43 pathogens of 24 different species. The most frequently found microorganisms were Gram-positive cocci (55.8%), including Staphylococcus Aureus (14.0%) and Epidermidis (14.0%). All Gram-negative bacilli amounted to 30.2% of the identified bacteria, including 9.3% of Pseudomonas aeruginosa. None of the Gram-positive cocci were resistant to vancomycin and all Gram-negative bacilli were susceptible to ceftazidime and amikacin. Following treatment with at least one of the three antibiotic eye drops produced by our pharmacy (amikacin at 50mg/mL, ceftazidime at 50mg/mL and vancomycin at 25mg/mL), patients' visual acuity was significantly improved (P=0.043).

CONCLUSION

The study helped identify the bacterial ecology of patients admitted for infectious keratitis. Among the bacteria identified, none were found to be resistant to any of the three strengthened antibiotic eye drops produced by the hospital pharmacy. These eye drops allowed for a rapid and effective treatment of patients and the improvement of their visual acuity before even identifying the bacteria.

Clinical Features, Antibiotic Susceptibilities, and Treatment Outcomes of Endophthalmitis Caused by Staphylococcus epidermidis

PURPOSE

To report the clinical features, antibiotic susceptibilities, and visual acuity outcomes with endophthalmitis caused by methicillin-sensitive Staphylococcus epidermidis and methicillin-resistant S. epidermidis.

DESIGN

Retrospective case series.

PARTICIPANTS

All patients seeking treatment at a tertiary referral center between 2006 and 2016 with endophthalmitis caused by S. epidermidis.

METHODS

All records were reviewed for patients with a clinical diagnosis of endophthalmitis and positive vitreous culture results for S. epidermidis. Data were compared with the prior series at the same institution.

MAIN OUTCOME MEASURES

Clinical settings, antibiotic susceptibilities, and visual acuity.

RESULTS

Among 96 eyes of 96 patients, the most common postprocedural clinical settings were cataract surgery (47/96 [49%]), intravitreal injection (21/96 [22%]), trauma (8/96 [8%]), glaucoma surgery (7/96 [7%]), and penetrating keratoplasty (5/96 [5%]). The initial treatment included intravitreal vancomycin and ceftazidime in 89 of 96 eyes (93%) and intravitreal vancomycin and amikacin in 7 of 96 eyes (7%). A vitreous tap and injection with antibiotics was performed as the initial treatment in 83 of 96 eyes (86%) and pars plana vitrectomy was performed in 13 of 96 eyes (14%). All isolates were sensitive to vancomycin in both decades. In the most recent series, visual acuity at last follow-up was 5/200 or better in 68 of 96 eyes (71%) compared with 71 of 86 eyes (83%) in the prior study. In the current study, susceptibility to methicillin and moxifloxacin was present in 45 of 96 eyes (47%) and 29 of 85 eyes (34%), respectively, compared with 34 of 86 eyes (40%) and 27 of 39 eyes (69%) in the prior study. Final visual acuity was not significantly different between those eyes that were methicillin or fluoroquinolone sensitive and those that were resistant.

CONCLUSIONS

In the current and prior series, all S. epidermidis isolates were sensitive to vancomycin. Visual acuity outcomes were not dependent on methicillin or fluoroquinolone sensitivity.

Feline-transmitted Staphylococcal hyicus endophthalmitis after clear lens extraction: a case report

Background

Postoperative endophthalmitis is a dreaded postsurgery complication which may lead to legal blindness. In addition to typical risk factors, some minor episodes may also lead to the occurrence of endophthalmitis. The purpose of the current study was to report a case of acute postoperative endophthalmitis caused by Staphylococcus hyicus in a patient with a contact history of felines.

Case presentation

A 58-year-old Taiwanese female who had a history of contact with felines due to her occupation had received clear lens extraction surgery of the left eye on July 10, 2015. One day after the surgery, the best-corrected visual acuity (BCVA) of the left eye was 20/40, which rapidly deteriorated to light perception with hypopyon formation. She was admitted for acute postoperative endophthalmitis and received antibiotic therapy with topical levofloxacin instillation and intravitreal vancomycin plus amikacin injection. Trans pars plana vitrectomy (TPPV) was then performed 1 day after admission. The specimen obtained from the vitreous and anterior chambers yielded the growth of S. hyicus. The patient was discharged with BCVA measured by counting fingers. Another TPPV was arranged for the persistent vitreous opacity on October 20, 2015, and the BCVA recovered to 20/32 at the last visit.

Conclusion

To our knowledge, this is the first case of acute postoperative endophthalmitis caused by S. hyicus due to feline contact. Unusual pathogens in the environment and personal hygiene status should be validated preoperatively to prevent the development of postoperative endophthalmitis.