agar and acetamide

We studied the efficience of the following broths for the enrichment of Pseudomonas aeruginosa: asparagine broth, malachite green broth, acetamide broth I (1% acetamide) and II (0.2% acetamide). A total of 275 P. aeruginosa containing sewage water samples was investigated. We isolated 784 P. aeruginosa strains. 6.3% of them produced no pyocyane. Until now the acetamide broth was used only diagnosticly but it can be employed also for enrichment. The acetamide broths had yields of 85.1%, 78.0% respectively. The asparagine broth showed a yield of 73.8% and the malachite green broth of 62.9% (Table 1). The comparison of the two used agars showed isolation quotas of 77.1% on cetrimide agar and of 58.3% on endo agar (Table 1). Incubation at 36 degrees C during 48 hours yielded more strains in all broths, the most in malachite green broth. However, the acetamid broth I showed already a decay of some organisms (Table 2).

Topics: Acetamides; Agar; Asparagine; Cetrimonium; Cetrimonium Compounds; Culture Media; Pseudomonas aeruginosa; Rosaniline Dyes