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2017 Agenda and Abstracts | < Previous Next >
2017 OMIG Abstract 10 Increasing frequency of sheen isolates among Pseudomonas aeruginosa keratitis isolates
Purpose: Pseudomonas aeruginosa causes vision-threatening keratitis. Approximately 20% of keratitis Pseudomonas aeruginosa isolates from the SCUT demonstrated a colony sheen appearance, and these sheen positive isolates correlated with a worse clinical outcome. These sheen isolates were found in India between 2006 and 2010. The basis of the sheen phenotype was a build up of 4-hydroxy-2-heptylquinoline due to mutation of the lasR gene. It is not known whether North American P. aeruginosa keratitis isolates have this sheen phenotype. Here we screened keratitis isolates from 1988-2015 for a sheen phenotype and sequenced the lasR gene from a subset of the sheen positive isolates. Methods: 103 P. aeruginosa keratitis isolates were streaked out on blood agar plates and analyzed for colony sheen phenotypes. The lasR gene was cloned and sequenced from a subset of these isolates. Results: Sheen positive isolates were found in 18% of isolates in the Campbell Laboratory collection of keratitis isolates. There is an increasing trend in the frequency of sheen positive isolates with 7.7% from isolates from 1988-1997 (n=36) and 26.5% from isolates between 2008-2015 (n=25). The majority of tested sheen positive isolates had mutations in the lasR gene. Conclusions: P. aeruginosa sheen isolates which were previously isolated from North American keratitis patients with a similar overall frequency to those observed in India. There is a trend for increasing sheen isolates that is concerning given the likely increased pathogenesis of these strains. Disclosure: N
2017 Agenda and Abstracts | < Previous Next >
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