Outbreak of multidrug-resistant acute postoperative endophthalmitis due to Enterobacter aerogenes

Exogenous endophthalmitis caused by Enterobacter cloacae following water gun injury

Enterobacter is a Gram-negative anaerobic bacillus. Enterobacter-associated endophthalmitis is rare. We report Enterobacter cloacae-associated traumatic endophthalmitis following a water gun injury with no visible external entry wound. A 46-year-old man presented with features masquerading as traumatic uveitis in his left eye following injury by water stream from a toy gun. He was started on topical steroids but within 2 days of initial presentation, there was worsening of vision, presence of hypopyon in the anterior chamber and presence of vitreous exudates confirmed on ocular ultrasound B-scan. Endogenous endophthalmitis was ruled out by extensive work-up including sterile urine and blood cultures. Emergency vitrectomy was done along with lensectomy and silicone oil implantation. E. cloacae were isolated from the vitreous sample, which were sensitive to all standard antibiotics tested. Final visual acuity was 20/200. Traumatic endophthalmitis is usually preceded by a penetrating ocular injury in the form of a corneal, limbal or scleral tear with or without choroidal tissue prolapse and vitreous prolapse. A high index of suspicion is, therefore, needed for the diagnosis of endophthalmitis in the absence of corneal injury following water jet trauma to the eye.

Antibiotic prophylaxis for cataract surgery - Practice patterns amongst Indian Ophthalmologists

Purpose

To assess the current trends in use of perioperative antibiotic prophylaxis, especially intracameral antibiotics (ICAB), for cataract surgery in India.

Methods

This was an E-survey using a previously validated questionnaire carried out by the All India Ophthalmological Society (AIOS) in August 2022. An E-mail invitation to complete an online 40-point survey was sent to all members of the AIOS using a digital E-mail service (Survey Monkey) and social media platforms.

Results

Out of 1804 total respondents, 58% (n = 1022) reported using routine ICAB prophylaxis. Of those using ICAB, 89% (n = 909) reported using it for all cases, whereas the rest used it for specific indications such as post-PC rent (n = 43), one eyed patient (n = 19), and high-risk cases (n = 50). Commercially available moxifloxacin was by far the commonest agent used for ICAB (n = 686, 67%). Eighty respondents (8%) reported noticing occasional toxic reactions and nontoxic corneal edema (n = 64, 6%) with ICAB. Surgeons with >10 years' experience especially practicing in medical colleges used fewer ICAB (OR = 0.52, 95%CI = 0.38 - 0.72, P < 0,001) compared to younger surgeons (<5-year experience) in solo clinics. The commonest reason for nonadoption of IC antibiotics was "unconvinced of the need to use it in my setting" (n = 296, 52% of those who answered this question).

Conclusion

IC antibiotic prophylaxis for cataract surgery has significantly increased in India from 40% in 2017 to 58% in 2022. Commercially available moxifloxacin was preferred by the majority users. Intraocular inflammation may occur occasionally and needs safer formulations to avoid this.

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.

Pars Plana Vitrectomy for Endophthalmitis: Microbiologic Spectrum and Clinical Outcomes

Purpose: To report visual outcomes, microbiologic spectrum, and antibiotic resistance in endophthalmitis patients undergoing pars plana vitrectomy (PPV).Methods: Retrospective study of 32 patients who underwent PPV with microbial analysis. Linear mixed models were utilized to compare visual acuity (VA).Results: Streptococcal species and coagulase-negative staphylococcus (CoNS) were the most common organisms. No resistance to vancomycin or fluoroquinolones was observed. Culture-negative individuals had better VA and lower incidences of retinal detachment (RD) and hypotony and better VA than culture-positive group at post-surgical month 3 (p = .025) and marginally at month 12 (p = .098). CoNS endophthalmitis (final logMAR VA 0.80) was associated with better VA than Streptococcal endophthalmitis (final logMAR VA 2.36) (p = .001). Secondary RD was observed in 33.3% of non-cataract endophthalmitis.Conclusion: No organisms were resistant to vancomycin or fluoroquinolones. Culture-negative endophthalmitis had better VA and lower rates of RD and hypotony than culture-positive group. A high rate of RD was observed in non-cataract endophthalmitis.

Comparative efficacy of two different topical povidone-iodine 5% regimens in reducing conjunctival bacterial flora: A randomized parallel double-masked clinical trial

INTRODUCTION

The increasing prevalence of multi-resistant bacteria is a major public health concern. Infections acquired during ophthalmic surgery are devastating. The purpose of the current study is to compare the proportion of eyes with negative bacterial cultures on all tested media after 1 versus 3 sequential drops of povidone-iodine (PI) 5% into the inferior conjunctival fornix.

METHODS

Patients were randomly assigned to receive 1 (PI group) drop (at time 28 minutes) or 3 (PI plus group) sequential drops (at time 0, 20 minutes and 28 minutes) of PI 5% into the inferior conjunctival sac of one randomly selected eye. A swab culture was obtained from the inferior conjunctival fornix 5 minutes before and 30 minutes after time 0. Central corneal thickness (CCT) was measured shortly before time 0 and shortly after time 30. Conjunctival swabs were incubated aerobically in enriched Thioglycolate liquid medium (meat broth) and in three solid culture media (chocolate agar, trypticase soy agar with 5% sheep blood, and Sabouraud agar).

RESULTS

There was no significant difference in the proportion of negative cultures after intervention between groups (p = 0.1638). Also in the PI group (n = 59), the proportion of eyes with negative cultures after PI (79.7%) did not differ significantly from baseline (76.3%; p = 0.7539). However in the PI plus group (n = 61), the proportion of eyes with all negative cultures after PI (85.3%) was significantly higher than before PI (70.5%) (p = 0.0177). There was no significant difference in mean CCT before and after the intervention in both groups.

CONCLUSION

Instillation of 3 sequential drops of PI was associated with a significant increase in the proportion of eyes with all negative cultures, while instillation of a single drop of PI was not associated with a significant increase in the proportion of negative cultures. Further study is warranted to determine whether the difference between the PI administration regimens is also associated with differences in the rates of postoperative ocular infections.

Infections Caused by Antimicrobial Drug-Resistant Saprophytic Gram-Negative Bacteria in the Environment

Background

Drug-resistance genes found in human bacterial pathogens are increasingly recognized in saprophytic Gram-negative bacteria (GNB) from environmental sources. The clinical implication of such environmental GNBs is unknown.

Objectives

We conducted a systematic review to determine how often such saprophytic GNBs cause human infections.

Methods

We queried PubMed for articles published in English, Spanish, and French between January 2006 and July 2014 for 20 common environmental saprophytic GNB species, using search terms “infections,” “human infections,” “hospital infection.” We analyzed 251 of 1,275 non-duplicate publications that satisfied our selection criteria. Saprophytes implicated in blood stream infection (BSI), urinary tract infection (UTI), skin and soft tissue infection (SSTI), post-surgical infection (PSI), osteomyelitis (Osteo), and pneumonia (PNA) were quantitatively assessed.

Results

Thirteen of the 20 queried GNB saprophytic species were implicated in 674 distinct infection episodes from 45 countries. The most common species included Enterobacter aerogenes, Pantoea agglomerans, and Pseudomonas putida. Of these infections, 443 (66%) had BSI, 48 (7%) had SSTI, 36 (5%) had UTI, 28 (4%) had PSI, 21 (3%) had PNA, 16 (3%) had Osteo, and 82 (12%) had other infections. Nearly all infections occurred in subjects with comorbidities. Resistant strains harbored extended-spectrum beta-lactamase (ESBL), carbapenemase, and metallo-β-lactamase genes recognized in human pathogens.

Conclusion

These observations show that saprophytic GNB organisms that harbor recognized drug-resistance genes cause a wide spectrum of infections, especially as opportunistic pathogens. Such GNB saprophytes may become increasingly more common in healthcare settings, as has already been observed with other environmental GNBs such as Acinetobacter baumannii and Pseudomonas aeruginosa.

Update on the prevention and treatment of endophthalmitis

Endophthalmitis remains a rare but serious cause of visual loss. Over time, changes have been noted in endophthalmitis in terms of predominant causes, infecting organisms, and antibiotic susceptibilities. There is controversy regarding the use of intracameral prophylactic antimicrobials during cataract surgery. Alternatively, there appears to be increasing evidence against using routine topical antibiotics for intravitreal injections. There are also increasing reports of multidrug-resistant organisms causing endophthalmitis, but the combination of vancomycin and ceftazidime appears effective for the vast majority of cases. Future trends may involve increasing utilization of polymerase chain reaction for diagnosis, and possibly office-based pars plana vitrectomy for treatment of endophthalmitis.