Abstract
Purpose:
Intraocular cultures from patients with infectious endophthalmitis are important in confirming clinical diagnosis and in planning treatment strategies. The purpose of this study was to compare the microbiological outcomes of membrane filter system (MFS) and blood culture bottle (BCB) techniques in culturing diluted vitrectomy cassette vitreous.
Methods:
Vitreous specimens from 03/25/02 to 07/11/12 were cultured using both MFS and BCB. The isolates were divided into three groups: the ones that had positive cultures with (1) both MFS and BCB, (2) only with MFS, and (3) only with BCB. The 24- and 48- hour as well as 1- and 2- week results were documented.
Results:
A total of 447 patients with 168 positive cultures were studied. At the 48- hour time point, 126 isolates were documented. Of those, (1) 104 were culture positive with both MFS and BCB (82%), (2) 15 (12%) were culture positive only with MFS, and (3) 7 (6%) were culture positive only with BCB. At the 2-week time point, an additional 42 organisms were isolated. Of those, (1) 19 (45%) were culture positive with both MFS and BCB, (2) 11 (26%) only with MFS, (3) 12 (29%) only with BCB. Out of total 168 isolates, (1) 123 (73%) were culture positive with both MFS and BCB, (2) 26 (16%) only with MFS, (3) 19 (11%) only with BCB. Among all microbiological outcomes, there was no significant difference between MFS and BCB (p=0.37). Of those organisms that were culture positive only with either MFS or BCB, mold and Mycobacterium species were culture positive more commonly with MFS (p=0.034 and 0.016, respectively), and gram-positive organisms were culture positive more commonly with BCB (p=0.021).
Conclusions:
In the current study, a combination of MFS and BCB for culture of diluted vitrectomy cassette vitreous provides the highest number of positive culture outcomes. BCB method is technically easier and represents a viable alternative to the more complex MFS technique.
Keywords: 513 endophthalmitis •
593 microbial pathogenesis: clinical studies •
763 vitreous