Comparison of the most common isolates of postoperative endophthalmitis in South Korea; Enterococcus species vs coagulase-negative staphylococci

Delayed Bacterial Endotheliitis and Endophthalmitis 11 Years after Cataract Surgery

Infective endophthalmitis is an uncommon complication following intraocular surgery. Chronic endophthalmitis may present some time after intraocular surgery, making the diagnosis challenging. Cutibacterium acnes is a well-recognised causative agent of these chronic infections. Practitioners should be aware of the conditions required to culture this slow-growing organism. We report a case of delayed low-grade endophthalmitis presenting 11 years after cataract surgery. Cutibacterium acnes and Staphylococcus warneri were cultured from Descemet's membrane biopsy following three failed previous attempts at microbiological studies. Clinical features of the infection included discrete white granules on the iris, endothelium, and within the capsular bag of the patient's right eye. The patient presented with no signs of systemic infection and the left eye was normal on examination. Bullous keratopathy, secondary to endothelial dysfunction was a feature of this infection. This retrospective case report illustrates the prolonged periods for which Cutibacterium acnes can remain latent before causing clinical signs. While uncommon, endothelial involvement may occur and clinicians should consider low-grade infective endophthalmitis in cases with corneal oedema.

Hydroalcoholic Leaf Extract of Punica granatum, alone and in Combination with Calcium Hydroxide, Is Effective against Mono- and Polymicrobial Biofilms of Enterococcus faecalis and Candida albicans

Failures in endodontic treatments are mostly associated with the difficulty in eradicating microbes of the root canal system, highlighting the need to develop novel effective antimicrobials. Punica granatum (pomegranate) leaf hydroalcoholic extract may be a potential alternative in canal dressing, owing to its antimicrobial properties. The objective of this study was to evaluate the antimicrobial activity of hydroalcoholic leaf extract of Punica granatum (HEPg) alone or in combination with calcium hydroxide (Ca(OH)₂) against Enterococcus faecalis and Candida albicans in isolation and in mono- and polymicrobial biofilms. Microdilution tests in broth and assays for inhibition of biofilm formation were carried out to evaluate the antimicrobial properties of HEPg and HEPg + Ca(OH)₂ against Enterococcus faecalis and Candida albicans. The cytotoxicity of HEPg in HaCaT cells was evaluated by MTT assay. HEPg and HEPg + Ca(OH)₂ exerted significant antimicrobial activity against planktonic cells and mono- and polymicrobial biofilms. The combination of Punica granatum extract with Ca(OH)₂ appears to be a promising alternative in endodontic treatments, which could be tested in vivo to confirm the efficacy of this mixture in disinfecting root canal systems.

Enterococcus faecalis Endophthalmitis: Clinical Settings, Antibiotic Susceptibility, and Management Outcomes

Enterococcus faecalis is known to cause severe acute endophthalmitis and often leads to poor visual outcomes in most ophthalmic infections. This retrospective study is to report the clinical settings, antimicrobial susceptibility patterns, and visual outcome of E. faecalis endophthalmitis at a tertiary referral institution in Taoyuan, Taiwan. E. faecalis endophthalmitis was diagnosed in 37 eyes of 37 patients. Post-cataract surgery was the most common cause (n = 27, 73%), followed by bleb-associated (n = 3, 8%), endogenous (n = 2, 5%), corneal ulcer-related (n = 2, 5%), post-vitrectomy (n = 1, 3%), post-pterygium excision (n = 1, 3%), and trauma (n = 1, 3%). Visual acuities upon presentation ranged from counting fingers to no light perception. Pars plana vitrectomy with intravitreal antibiotics were performed in 23 eyes (76%) as primary or secondary treatment. All isolates (37/37, 100%) were sensitive to vancomycin, penicillin, ampicillin, and teicoplanin. Six of 22 eyes (27%) were resistant to high-level gentamicin (minimum inhibitory concentration > 500 mg/L). Final visual acuities were better than 20/400 in 11 eyes (30%), 5/200 to hand motions in 4 eyes (11%), and light perception to no light perception in 22 eyes (59%). Three eyes were treated with evisceration. Compared with non-cataract subgroups, the post-cataract subgroup showed a significant difference of better visual prognosis (p = 0.016).

Emerging Enterococcus isolates in postoperative endophthalmitis by selection pressure of fluoroquinolones: an 11-year multicenter and experimental study

Postoperative endophthalmitis (PE) is the devastating complication that frequently results in vision loss. Recently, enterococcus have emerged as a major cause of PE in several countries and resulted in poor visual outcome. However, the reason remains elusive. We investigate whether selection pressure of fluoroquinolone exerts effects on microorganism profiles isolated from PE. Medical records of patients who were diagnosed with PE at eight resident training institutions between January 2004 and December 2015 were reviewed. The most common isolate was Enterococcus faecalis (28.0%), followed by Staphylococcus epidermidis (18.6%) and other coagulase negative Staphylococci (7.6%). However, the rates of E. faecalis isolated from conjunctival microbes were 6.2% (16/257) and their resistance to fluoroquinolones was higher than those of S. epidermidis. In vitro and in vivo co-culture models of E. faecalis and S. epidermidis were established for survival assays after administration of fourth-generation fluoroquinolone. In in vitro co-culture model, the survival assay of E. faecalis and S. epidermidis against the treatment of moxifloxacin showed that E. faecalis survived significantly better than S. epidermidis in the presence of moxifloxacin 1 µg/mL and more. In in vivo co-culture model, E. faecalis survived significantly better than S. epidermidis after topical treatment of moxifloxacin (5 mg/mL). E. faecalis has been the most common causative strain of PE in Korea. We suggest that the increase of E. faecalis in PE could be associated with the selection pressure of fourth-generation fluoroquinolone.

Summary:Enterococcus spp. have emerged as a leading causative strain of postoperative endophthalmitis in 11-year clinical data. We suggest that the increase of Enterococcus spp. is associated with the selection pressure of fourth-generation fluoroquinolone.