Abstract
Purpose: :
Anaerobic bacteria are etiological agents of ocular infection that require suitable atmospheric conditions for isolation on culture media. We tested the OxyPlateTM Anaerobic System (OXY) for its utility to isolate pertinent anaerobic bacteria that caused endophthalmitis and other ocular disease.
Methods: :
OXY, which does not require direct anaerobic conditions, was compared to conventional isolation of incubating culture media in anaerobic bags. Standard colonies counts were performed on anaerobic ocular bacterial isolates under aerobic and anaerobic (anaerobic bags) conditions using agar media: 1) OXY (aerobic only), 2) 5% Sheep Blood, 3) Chocolate, and 4) Schaedler. The bacteria tested were de-identified ocular isolates cultured from endophthalmitis and dacryocystitis: These included 10 isolates of Propionibacterium acnes, and 3 isolates of Actinomyce species. The colony counts for each bacteria isolate, on each culturing condition, were ranked from largest to smallest. The ranks were non-parametrically compared to determine the culturing condition with the highest amount of colony counts.
Results: :
As an anaerobic system, a 5% Sheep blood plate in an anaerobic bag isolated higher colony counts than OXY (p=.0028) and chocolate agar (p=0.0028). All anaerobic conditions were able to isolate all of the anaerobic bacterial isolates. 5% Sheep Blood agar and Schaedler’s agar under aerobic conditions did not support the growth of anaerobic bacteria. Sparse growth was noted on chocolate agar for Propionibacterium acnes.
Conclusions: :
Although OXY did not test to be more efficient than other anaerobic systems, it appears to be a reasonable alternative for isolating anaerobic bacteria from ocular sites. The use of an agar medium in a specially designed plate, without the requirement of an anaerobic bag, rendered OXY as an advantage over other anaerobic systems.
Keywords: bacterial disease • microbial pathogenesis: experimental studies