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

BACKGROUND: An observational case series was used to study the virulence characteristics and genotypes of paired Staphylococcus epidermidis isolates cultured from intraocular samples and from periocular environment of patients with postcataract surgery endophthalmitis. METHODS: Eight S. epidermidis 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 icaAB and mecA gene respectively. RESULTS: Four out of eight S. epidermidis strains showed multiple drug resistance (MDR). All the eight strains were PCR positive for mecA gene whereas seven out of eight strains were positive for icaAB genes. In all three patients FAFLP typing established vitreous isolates of S. epidermidis 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 icaAB gene. In silico analysis indicated possible evolution of other strains from this strain in the patient. CONCLUSION: Methicillin-resistant biofilm positive S. epidermidis strains colonizing the conjunctiva and eyelid were responsible for postoperative endophthalmitis (POE)

A New Method to Predict the Epidemiology of Fungal Keratitis by Monitoring the Sales Distribution of Antifungal Eye Drops in Brazil

Purpose: Fungi are a major cause of keratitis, although few medications are licensed for their treatment. The aim of this study is to observe the variation in commercialisation of antifungal eye drops, and to predict the seasonal distribution of fungal keratitis in Brazil. Methods: Data from a retrospective study of antifungal eye drops sales from the only pharmaceutical ophthalmologic laboratory, authorized to dispense them in Brazil (Opthalmos) were gathered. These data were correlated with geographic and seasonal distribution of fungal keratitis in Brazil between July 2002 and June 2008. Results: A total of 26,087 antifungal eye drop units were sold, with a mean of 2.3 per patient. There was significant variation in antifungal sales during the year (p < 0.01). A linear regression model displayed a significant association between reduced relative humidity and antifungal drug sales (R-2 = 0.17, p < 0.01). Conclusions: Antifungal eye drops sales suggest that there is a seasonal distribution of fungal keratitis. A possible interpretation is that the third quarter of the year (a period when the climate is drier), when agricultural activity is more intense in Brazil, suggests a correlation with a higher incidence of fungal keratitis. A similar model could be applied to other diseases, that are managed with unique, or few, and monitorable medications to predict epidemiological aspects.Conselho Nacional de Desenvolvimento Cientifico e TecnologicoConselho Nacional de Desenvolvimento Cientifico e Tecnologico [302005/2009-9]Fundacao de Apoio ao Ensino, Pesquisa e Assistencia do Hospital das Clinicas da Faculdade de Medicina de Ribeirao Preto da Universidade de Sao PauloFundacao de Apoio ao Ensino, Pesquisa e Assistencia do Hospital das Clinicas da Faculdade de Medicina de Ribeirao Preto da Universidade de Sao Paul

Management Strategies to Reduce Risk of Postoperative Infections

Postoperative infections, although rare, are still of great concern to the ophthalmologist. The incidence of post-cataract endophthalmitis is low, with a range of .28 per 1,000 to 2.99 per 1000. In addition to intraoperative considerations such as poor wound construction, vitreous loss, topical anesthesia, and prolonged surgical time, other risk factors include preoperative factors such as a diseased ocular surface and systemic immunosuppression. Potential methods of reducing risk of endophthalmitis after anterior segment surgery are discussed and available literature is summarized