Fluorescent amplified fragment length polymorphism (FAFLP) genotyping demonstrates the role of biofilm-producing methicillin-resistant periocular <it>Staphylococcus epidermidis </it>strains in postoperative endophthalmitis

• Main Authors: Hasnain Seyed E, Das Taraprasad, Pathengay Avinash, Ahmed Niyaz, Duggirala Aparna, Kenchappa Prashanth, Sharma Savitri
• Format: Article
• Language: English
• Published: BMC 2006-01-01
• Series: BMC Ophthalmology
• Online Access: http://www.biomedcentral.com/1471-2415/6/1

<p>Abstract</p> <p>Background</p> <p>An observational case series was used to study the virulence characteristics and genotypes of paired <it>Staphylococcus epidermidis </it>isolates cultured from intraocular samples and from periocular environment of patients with postcataract surgery endophthalmitis.</p> <p>Methods</p> <p>Eight <it>S. epidermidis </it>isolates were obtained from three patients (2 from patients #1 and 2 and 4 from patient #3) whose vitreous and/or anterior chamber (AC) specimens and preoperative lid/conjunctiva samples were culture positive. Cultures were identified by API-Staph phenotypic identification system and genotypically characterized by Fluorescent Amplified Fragment Length Polymorphism (FAFLP) and checked for their antimicrobial susceptibility. The isolates were tested for biofilm-production and methicillin-resistance (MR) by PCR amplification of <it>icaAB </it>and <it>mecA </it>gene respectively.</p> <p>Results</p> <p>Four out of eight <it>S. epidermidis </it>strains showed multiple drug resistance (MDR). All the eight strains were PCR positive for <it>mecA </it>gene whereas seven out of eight strains were positive for <it>icaAB </it>genes. In all three patients FAFLP typing established vitreous isolates of <it>S. epidermidis </it>strains to be indistinguishable from the strains isolated from the patient's conjunctival swabs. However, from patient number three there was one isolate (1030b from lid swab), which appeared to be nonpathogenic and ancestral having minor but significant differences from other three strains from the same patient. This strain also lacked <it>icaAB </it>gene. <it>In silico </it>analysis indicated possible evolution of other strains from this strain in the patient.</p> <p>Conclusion</p> <p>Methicillin-resistant biofilm positive <it>S. epidermidis </it>strains colonizing the conjunctiva and eyelid were responsible for postoperative endophthalmitis (POE).</p>