Enterococcal Ulcerative Keratitis in a 32-Year-Old Nigerian: A Rare Case

Ernest I Ezeh; Sunday N Okonkwo; Bassey O Bassey; Roseline N Ezeh; Nkama Etiowo; Ekama Egbe

doi:10.4103/njo.njo_4_22

CASE REPORT

Year : 2022 | Volume : 30 | Issue : 3 | Page : 119-122

Enterococcal Ulcerative Keratitis in a 32-Year-Old Nigerian: A Rare Case

Ernest I Ezeh¹, Sunday N Okonkwo¹, Bassey O Bassey², Roseline N Ezeh³, Nkama Etiowo³, Ekama Egbe³
¹ Department of Ophthalmology, University of Calabar, Calabar, Cross River State, Nigeria
² Pathology Division, University of Calabar Teaching Hospital, Calabar, Cross River State, Nigeria
³ Department of Ophthalmology, University of Calabar Teaching Hospital, Calabar, Cross River State, Nigeria

Date of Submission	01-Mar-2022
Date of Decision	20-Jul-2022
Date of Acceptance	10-Oct-2022
Date of Web Publication	09-Dec-2022

Correspondence Address:
Ernest I Ezeh
Department of Ophthalmology, University of Calabar, Calabar, PMB 1115, Cross River State, Nigeria
Nigeria

Source of Support: None, Conflict of Interest: None

Check

DOI: 10.4103/njo.njo_4_22

Abstract

Globally, most cases of microbial ulcerative keratitis are bacterial in origin. The most common causative organisms in bacterial keratitis are Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, and Pseudomonas aeruginosa. Ocular infections by enterococci are rare. Only a few cases of keratitis and endophthalmitis caused by enterococci have been reported worldwide. To the best of the authors’ knowledge, no case has been reported in Nigeria. We present a case of ulcerative keratitis due to Enterococci specie, to highlight the occurrence of this unusual ocular pathogen. A case of a 32-year-old male trader is presented with a 4-week history of severe painful red left eye, associated whitish discharge, sticky eyelids, tearing, profound visual loss, and whitish patch on the eye. Examination revealed paracentrally located 4.0 × 3.0 mm epithelial defect with an iris plugged 2 mm corneal perforation and an underlying dense, well-defined, white stromal infiltrate. Cultures yielded growth of E. specie, verified by biochemical tests (the Analytical Profile Index system Approach). He was managed on intensive antibiotics and made remarkable improvement. This highlights the need for Eye care practitioners to be mindful of the potential risk of unusual pathogen such as E. specie, causing cornea infection in our environment.

Keywords: enterococci, keratitis, ulcerative, hypopyon

How to cite this article:
Ezeh EI, Okonkwo SN, Bassey BO, Ezeh RN, Etiowo N, Egbe E. Enterococcal Ulcerative Keratitis in a 32-Year-Old Nigerian: A Rare Case. Niger J Ophthalmol 2022;30:119-22

How to cite this URL:
Ezeh EI, Okonkwo SN, Bassey BO, Ezeh RN, Etiowo N, Egbe E. Enterococcal Ulcerative Keratitis in a 32-Year-Old Nigerian: A Rare Case. Niger J Ophthalmol [serial online] 2022 [cited 2023 Jun 5];30:119-22. Available from: http://www.nigerianjournalofophthalmology.com/text.asp?2022/30/3/119/362906

Introduction

Microbial ulcerative keratitis is a public health problem, particularly in developing nations^{[1],[2],[3],[4],[5],[6],[7],[8],[9],[10],[11],[12],[13],[14],[15]} and is also a major cause of visual impairment worldwide.^{[1],[5],[8],[14],[15],[16],[17]} The spectrum of the causative pathogens of microbial ulcerative keratitis shows a wide geographical and some seasonal variation.^{[8],[10],[17]} Globally, most cases of microbial ulcerative keratitis are bacterial in origin^{[5],[16],[17]} and the most common bacteria are Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, and Pseudomonas aeruginosa.^{[1],[5],[10],[11],[16],[17]} In developing countries, available studies show that the etiologies vary.^{[1],[2],[3],[4]} Though bacterial keratitis appears to relatively predominate, fungal infections constitute a significant proportion. Some studies in East Africa and Ghana reported fungi as the leading cause of microbial keratitis.^{[3],[4],[7],[12]} However, in Nigeria, bacterial keratitis predominates, with fungal keratitis as a close second common type of microbial keratitis. Ocular infections by enterococci are rare.^[18] A few cases of keratitis and endophthalmitis caused by enterococci have been reported.^{[18],[19],[20],[21],[22],[23],[24]} In the literature, only very few cases of Enterococci related keratitis have been reported globally.^{[19],[23],[24]} To the best of the authors’ knowledge, no case has been reported in Nigeria. We present a case of ulcerative keratitis due to Enterococci specie, to highlight the occurrence of this unusual, opportunistic ocular pathogen in our environment.

Case Presentation

A 32-year-old male trader presented with a 4-week history of severe painful red left eye, which started on waking up from sleep. There was associated whitish discharge, tearing, profound visual loss, and whitish patch on the eye. Symptoms progressively worsened despite using Gtt. Ciprofloxacin 3 hourly and Gtt. Gentamycin 6 hourly dispensed at a secondary health facility for about 3 weeks. No history suggestive of immunosuppression or steroid use. He denied use of any other substance, except the prescribed eye drops, on his eye. Two weeks prior to onset, he had a splash of glass particles on his body (including his face) from a broken window glass of a public transport bus. Cycling (without eye protection) has been his common means of transportation. He has been experiencing occasional rectal bleed from hemorrhoid; which he was diagnosed of 4 years ago. On examination visual acuity was 6/6, right eye and Counting finger, left eye. The right eye was essentially normal. There was mild erythema and swelling of the left eyelids, with associated mild purulent discharge, and diffuse conjunctival injection. There was a paracentral corneal epithelial defect inferio-temporally measuring about 4.0 × 3.0 mm with an iris plugged 2 mm corneal perforation and an inferio-temporal shallow anterior chamber; as well as an underlying well-defined, dense, white stromal infiltrate measuring 7.0 × 5.0 mm and surrounding cornea edema [Figure 1]. A hairline hypopyon was present inferiorly. Red reflex was dull. A clinical diagnosis of left suppurative corneal ulcer with perforation was made.

Figure 1 Clinical photograph showing pooling of tears on inferior fornix, diffuse conjunctiva hyperemia, dense stromal infiltrate, and an iris plugged 2 mm corneal perforation. At Day 4 after commencement of treatment.

Click here to view

The patient was admitted, samples for full blood count, erythrocyte sedimentation rate, retroviral screening, fasting blood glucose, glycated hemoglobin, urinalysis, and eye conjunctival swab and corneal scraping for microscopy/culture/sensitivity were collected and intensive empirical antimicrobial medications with supportive therapy were commenced. He was treated intensively on Gtt. Moxifloxacin every 30 minutes, Gtt. Natamycin 5% 1 hourly, Gtt. Fotified Gentamycin (13.6 mg/mL) 3 hourly, Subconjunctival Ceftazidime 100 mg daily for 3 days, then alternate day × 3 doses, Gtt. Atropine 1% 8 hourly, Tab. Acetazolamide 250 mg qds, Caps. Doxycycline 100 mg bd, Gtt. Salacyn 4 hourly, and Tab. Vitamin C 300 mg tds.

Gram stain revealed Gram-positive cocci in singles, pairs, and short chains. Cultures showed Enterococci specie [Figure 2] verified by biochemical tests (the Analytical Profile Index System Approach). Other laboratory investigations were normal. The organism was sensitive to Linezolid, Cefixime/Clavulanic acid, and Ceftriaxone; intermediate sensitive to Ciprofloxacin and Amoxycillin/Clavulanic acid; and was resistant to Gentamycin. Hence, Gtt. Fortified Gentamycin was discontinued and replaced with Gtt. Ceftriaxone (50 mg/mL) 3 hourly.

Figure 2 Culture report on growth of Enterococci sp.

Click here to view

On treatment day 3, hypopyon had resolved and stromal infiltrate slightly diminished. On treatment day 7, doxycycline capsules were discontinued due to his complain of experiencing rectal bleed, which he attributed to the doxycycline capsules, as he has had the similar experience with doxycycline ingestion in the past. On treatment day 8, stromal infiltrate had diminished further, corneal edema remarkably resolved, and visual acuity had improved to 2/60 (eccentric fixation); hence frequency of Gtt. Moxifloxacin and Gtt. Natamycin instillation was tapered to 1 and 4 hourly respectively, and other medications continued. On treatment day 10, a 3 mm corneal perforation with iris plugging and shallow anterior chamber was noted. A 14.5 mm Hydrogel bandage contact lens (Acuvue, Johnson & Johnson, Florida, USA) was placed, eye patch applied, Gtt. Atropine was discontinued. He was continued on Gtt. Ceftriaxone (50 mg/mL) 3 hourly, Gtt. Moxifloxacin 6 hourly, Gtt. Natamycin 8 hourly, Tab. Acetazolamide 250 mg tds, and Tab. Vitamin C 300 mg tds. At the time (6 weeks from admission) of discharge from the hospital the visual acuity was 6/24, and the stromal infiltrate had resolved with dense stromal scar. He was discharged on Gtt. Ceftriaxone (50 mg/mL) 4 hourly, Gtt. Salacyn 6 hourly, and Tab. Vitamin C 300 mg tds. At 10 days follow up visit, visual acuity was still 6/24, there was paracentral stromal scar with adherent iris and largely formed anterior chamber.

Discussion

This case depicts an aggressive keratitis due to enterococci sp. Lee et al.^[24] had similarly reported a case of a 67-year-old male that developed enterococcal endophthalmitis and full thickness corneal ulcer on day 12 after the repair of a postoperative ruptured wound. The tissue destructive effects may be due to the virulence and a specific hemolytic toxin, cytolysin, produced by some enterococci spp.^[25],[26]

Furthermore, delay in commencement of appropriate antibiotic therapy may have contributed to the initial unrelenting course in the index patient. The earlier empirical antibiotic therapy (Ciprofloxacin, Gentamycin) commenced in this patient consisted of antibiotic medications with documented high minimum inhibitory concentration 90s (MIC 90s) on enterococci spp.,^[20] indicating a high level of resistance. Hence, the initial empirical antibiotic therapy commenced at the Secondary health facility are reportedly not highly effective against Enterococci species. The antibiotics sensitivity done on the index patient’s eye sample reported intermediate sensitivity to Ciprofloxacin and resistance to gentamycin. The commencement of the Cephalosporins, that is, Cetfazidime and Ceftriaxone, which was later noted with good sensitivity, were evidently quite helpful in this patient.

Notably, despite timely and aggressive treatment, enterococcal ocular infections are generally associated with poor outcomes.^{[18],[19],[20],[21],[22],[23],[24]} This may not be unrelated to its destructive effects and virulence in non-cavitary ocular tissues, antibiotic resistance tendency, and its being an unusual cause of ocular infection, hence low index of suspicion among clinicians. However, our index patient made a fairly good recovery, which may not be unrelated to the timely empirical commencement of the Cephalosporins, to which the sensitivity profile was high.

Enterococcal keratitis is rare. Only a few cases have been reported in the literature.^{[19],[23],[24]} Enterococci are gram positive, facultative anaerobic cocci. They are part of the normal intestinal flora of humans and animals, and are found in soil, sewage, water, and food frequently through fecal contamination. Enterococcal infections usually follow fecal contaminant, and it is commonly an opportunistic nosocomial infection (i.e., in a setting of antibiotic overuse, immunocompromise, colonization susceptibility, and virulence of non-gastrointestinal sites).^[27],[28] Enterococcus faecalis and E. faecium are the most common species that cause a variety of infections in humans, including endocarditis, urinary tract infections, prostatitis, intra-abdominal infection, cellulitis, and wound infection as well as concurrent bacteremia. Generally, enterococci are not as virulent as other gram-positive cocci and often occur as a component of a polymicrobial infection in debilitated hosts.^{[18],[27],[28]} Most cases of enterococcal ocular infections are post-surgical, and on a background of compromised ocular surface, while a few others follow non-surgical trauma.^{[18],[19],[20],[21],[22],[23],[24]} Of note, enterococci isolates from eyes are phylogenetically same as the general clinical isolates.^[29] In our index case, the splash of glass particles on his body from a broken window glass of a public transport bus likely contaminated, and patient’s contaminated hand or formites in the setting of hemorrhoid, may have being the source(s) for inoculation on to his eye.

Conclusion

Eye care practitioners should be mindful of the potential risk of unusual pathogen such as E. specie, causing cornea infection in our environment; particularly in communities with high levels of environmental contaminants and poor hygiene as well as in patients with gastrointestinal disorders. Timely corneal scrapping for microscopy, culture, and sensitivity is strongly advised for all cases of suppurative corneal ulcers.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1.	Ibanga AA, Etim BA, Nkanga DG, Asana UE, Duke RE. Corneal ulcers at the university of calabar teaching hospital in Nigeria − a ten year review. BMRJ 2016;14:1-10.
2.	Olawoye OO, Bekibele CO, Ashaye AO. Suppurative Keratitis in a Nigerian tertiary hospital. Niger J Ophthalmol 2011;19:27-9.
3.	Burton MJ, Pithuwa J, Okello E et al. Microbial Keratitis in East Africa: why are the outcomes so poor? Ophthalmic Epidemiol 2011;18:158-63.
4.	Arunga S, Kintokib GM, Mwesigye J et al. Epidemiology of microbial Keratitis in Uganda: a Cohort study. Ophthalmic Epidemiol 2020;27:121-31.
5.	Ezisi CN, Ogbonnaya CE, Okoye O, Ezeanosike E, Ginger-Eke H, Arinze OC. Microbial Keratitis—a review of epidemiology, pathogenesis, ocular manifestations, and management. Niger J Ophthalmol 2018;26:13-23. [Full text]
6.	Mehta R, Mehta P, Rao MVR, Acharya Y, Bala SA, Sowmya KJ. A study of fungal keratitis in North Africa: exploring risk factors and microbiological features. Int J Life Sci Scienti Res 2016;2:579-82.
7.	Leck AK, Thomas PA, Hagan M et al. Aetiology of suppurative corneal ulcers in Ghana and south India, and epidemiology of fungal keratitis. Br J Ophthalmol 2002;86:1211-15.
8.	Shah A, Sachdev A, Coggon D, Hossain P. Geographic variations in microbial Keratitis: an analysis of the peer-reviewed literature. Br J Ophthalmol 2011;95:762-67.
9.	Saka SE, Ademola-Popola DS, Mahmoud AO, Fadeyi A. Presentation and outcome of microbial Keratitis in Ilorin, Nigeria. BJMMR 2015;6:795-803.
10.	Arinze OC, Okoye O, Udeh NN et al. Ulcerative Keratitis: incidence, seasonal distribution and determinants in a tertiary eye care facility south east Nigeria. Central Afr J Med 2018;63:7-9.
11.	Oladigbolu K, Rafindadi A, Abah E, Samaila E. Corneal ulcers in a tertiary hospital in Northern Nigeria. Ann Afr Med 2013;12:165-70. [PUBMED] [Full text]
12.	Fungal Keratitis − Sub-Saharan Africa. Available at https://www.aao.org/topic-detail/fungal-keratitis-sub-saharan-africa-2 [accessed 12 November, 2021]
13.	Ajayi IA, Omotoye OJ, Ajite KO. Pattern of corneal disorders in Ekiti: a tertiary eye center experience. Ann Afr Med 2020;19:119-23
14.	Suwal S, Bhandari D, Thapa P, Shrestha MK, Amatya J. Microbiological profile of corneal ulcer cases diagnosed in a tertiary care ophthalmological institute in Nepal. BMC Ophthalmol 2016;16:209-14.
15.	Toth G, Pluzsik MT, Sandor GL et al. Clinical review of microbial corneal ulcers resulting in enucleation and evisceration in a tertiary eye care center in Hungary. J Ophthalmol 2020;2020:1-8.
16.	Egrilmez S, Yildirim-Theveny S. Treatment-resistant bacterial Keratitis: challenges and solutions. Clin Ophthalmol 2020;14:287-97.
17.	Bartimote C, Foster J, Watson S. The spectrum of microbial keratitis: an updated review. Open Ophthalmol J 2019;13:100-30.
18.	Barge S, Rothwell R, Varandas R, Agrelos L. Enterococcus faecalis endogenous endophthalmitis from valvular endocarditis. Case Rep Ophthalmol Med 2013;2013:1-4.
19.	Peng C, Cheng C, Chang C, Chen Y. Multiresistant enterococci: a rare cause of complicated corneal ulcer and review of the literature. Can J Ophthalmol 2009;44:214-15.
20.	Kuriyan AE, Sridhar J, Flynn Jr. HW et al. Endophthalmitis caused by enterococcus faecalis: clinical features, antibiotic sensitivities, and outcomes. Am J Ophthalmol. 2014;158:1018-23.
21.	Fraser SG, Ohri R. Endophthalmitis caused by Enterococcus faecalis. Eye 1995;9:535-36.
22.	Scott IU, Loo RH, Flynn Jr HW, Miller D. Endophthalmitis caused by enterococcus faecalis: antibiotic selection and treatment outcomes. Ophthalmology 2003;110:1573-77.
23.	Rau G, Seedor JA, Shah MK, Ritterband DC, Koplin RS. Incidence and clinical characteristics of enterococcus keratitis. Cornea 2008;27:895-99.
24.	Lee SM, Lee JH. A case of Enterococcus faecalis endophthalmitis with corneal ulcer. Korean J Ophthalmol 2004;18:175-9.
25.	Forster RK. Experimental postoperative endophthalmitis. Trans Am Ophthalmol Soc 1992;90:505-59.
26.	Jett B, Jensen H, Nordquist R, Gilmore M. Contribution of the pAD1-encoded cytolysin to the severity of experimental enterococcus faecalis endophthalmitis. Infect Immun 1992;60:2445-52.
27.	Agudelo Higuita NI, Huycke MM. Enterococcal disease, epidemiology, and implications for treatment. In: Gilmore MS, Clewell DB, Ike Y et al., eds. Enterococci: From Commensals to Leading Causes of Drug Resistant Infection [Internet]. Boston: Massachusetts Eye and Ear Infirmary 2014 pp. 1-35.
28.	Garsin DA, Frank KL, Silanpää J et al. Pathogenesis and models of Enterococcal infection. In: Gilmore MS, Clewell DB, Ike Y et al., eds. Enterococci: From Commensals to Leading Causes of Drug Resistant Infection [Internet]. Boston: Massachusetts Eye and Ear Infirmary; 2014 pp. 1-73.
29.	Todokoro D, Eguchi H, Suzuki M et al. Genetic relatedness of Enterococcus faecalis between eye-associated isolates and the other clinical isolates. Investig Ophthalmol Visual Sci 2014;55:1479-83.