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Sir,

Postoperative endophthalmitis is a dreadful complication after uncomplicated cataract surgery. Acute postoperative endophthalmitis has been reported with various organisms; particularly Gram-positive cocci are known to cause endophthalmitis in the first 48 h after surgery.

Leuconostoc mesenteroides has been reported as a cause of nosocomial urinary tract infection, infection in patients with neutropenia and cancer, prosthetic valve endocarditis, liver transplantation, severe burn injuries, and AIDS.1, 2, 3, 4, 5, 6, 7, 8, 9 Intrinsically, vancomycin-resistant Gram positives are usually opportunistic pathogens. To our knowledge, this is the first case report of L. mesenteroides endophthalmitis after phacoemulsification.

Case report

A healthy 76-year-old gentleman has a routine uncomplicated phacoemulsification with posterior chamber implantation. After 48 h, he presented to the casualty department with very poor vision and pain in the operated eye even though he could see well after 24 h after surgery. He had noticed some floaters prior to complete loss of vision. He did not have any ocular or systemic disease, that could predispose for a postoperative infection. He presented with only ‘perception of light’, hypopyon, slightly elevated (23 mmHg) intraocular pressure and fundus could not be seen due to vitreous opacification. A diagnosis of endophthalmitis was made and vitreous biopsy was carried out urgently, which included intravitreal injection of vancomycin and amikacin at the end of the procedure. Initial microbiologic examination showed Gram-positive cocci and he was treated with systemic ciprofloxacin and prednisolone. He also received topical gentamicin, ciprofloxacin, and cycloplegics. After 48 h, culture showed L. Mesenteroides that was sensitive to gentamicin, erythromycin, and chloromphenicol, but resistant to vancomycin, penicillin, ceftazidime, and amikacin. His symptoms improved in 3 days, but vision remains ‘hand movements’ after 3 months.

This report highlights the importance of Leuconostoc spp as an emerging pathogen, even though the modes of transmission and reservoirs are yet unknown.

Comment

L. Mesenteroides are Gram-positive cocci in pairs or short chains. They are microaerophilic; catalase-negative, ferment sugars, and produce gas. Species of this genus are normally present in plant materials, dairy products, and other fermented food stuffs as well as spoiled foods so that they are likely to be encountered in public health laboratories; such isolates are usually vancomycin-resistant. They have been isolated from the blood cultures and, as with pediococci, some were resistant to vancomycin.4 In the laboratory, detran-forming cultures may be confused initially with Streptococcus bovisbiotype, because both yield watery colonies on sucrose agar and share other biochemical characteristics. The Leuconostoc differ from other Gram-positive catalase-negative cocci in that they grow in air with or without added CO2.

Although serious infections may occur, treatment options remain available. No additional infection control measures for intrinsically resistant genera appear justified with currently available evidence, although vigilance should be maintained to detect culture changes in susceptibility patterns. L. Mesenteroides should be considered as a potential cause of infective endophthalmitis and listed in the group of vancomycin-resistant microorganisms.