Coagulase-negative Staphylococci strain types affect visual outcome in patients with endophthalmitis

Abstract number: 902_p1018

Lightman S.


To determine whether the variable visual outcome in endophthalmitis secondary to coagulase-negative Staphylococci spp. are due to different strains causing intraocular infection, with a possible difference in virulence of each strain or resistance to the antibiotics given.


Twenty-eight intraocular samples infected with coagulase-negative Staphylococci spp. were analysed using both biotyping and pulsed-field gel electrophoresis for strain identification. The results were correlated with the visual outcome after 6 months post-treatment.


Four different strains of coagulase-negative Staphylococci spp. were found to cause endophthalmitis; S. epidermidis, S. haemolyticus, S. equorum and S. warneri. Twenty-one out of the 28 isolates were identified as S. epidermidis and the others were grouped as non- S. epidermidis for correlation with the clinical data. Comparing the S. epidermidis with the non- S. epidermidis infected cases, it was found that the mean visual gain was significantly better for the non- S. epidermidis infected cases [(mean visual gain of 38.1 vs. 83.3 LogMAR letters, respectively) (P = 0.029)].The visual outcome was significantly worse for patients infected with S. epidermidis and antibiotic resistance was more common among these isolates although all were sensitive to at least one of the three/four antibiotics given. Comparing the non- S. epidermidis infected cases to the S. epidermidis infected cases that were sensitive to all four antibiotics used, the visual outcome was still significantly better in the non- S. epidermidis group [mean visual gain 83.3 vs. 25.75 LogMAR letters, respectively) (P = 0.022)].


SE carries a significantly worse visual outcome than non-SE strains of CNS and is likely to be due to increased virulence within the eye rather than antibiotic resistance.


Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Location: Oxford, UK
Presentation type:
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