2009 Volume 26 Issue 3 Pages 183-186
Twenty-four Shigella spp. strains randomly selected from 58 stock strains were analyzed for hemolytic activity on enterohemolysin blood agar (E-Hly agar) incubated at 35°C and 44°C in aerobic and anaerobic conditions. Hemolytic activity was observed more clearly in the case of incubation at 44°C than 35°C. Therefore, all Shigella spp. stock strains (50 S. sonnei strains, seven S. flexneri strains, one S. boydii strain) and 36 strains of Enterobacteriaceae were analyzed for hemolytic activity on E-Hly agar incubated at 44°C for 20 hr in aerobic and anaerobic conditions. All Shigella spp. strains were positive for hemolytic activity in anaerobic incubation however some Shigella spp. strains were negative in aerobic incubation. Though, some strains of Enterobacteriaceae were hemolytic on E-Hly agar, these strains were considered to distinct from Shigella spp. strains on selective agar.
We tried to recover S. sonnei from spiked Japanese littleneck clam samples. S. sonnei was recovered by screening test using marker of hemolytic activity on E-Hly agar incubated at 44°C for 20 hr in anaerobic condition.