Analysis of cost and accuracy of alternative strategies for Enterobacteriaceae identification

Analysis of the cost of time and material required for the diagnosis of Enterobacteriaceae isolates indicated that a conventional 17 tube (20 test) setup costs $7.98 per isolate identified. Using the API 20E, a similar identification cost $3.02. A conventional 7 tube (10 test) setup cost $3.60, whereas the comparable API 10S cost $2.33. Compared with the API 10S, using the API 20E increased costs by 30% while increasing the number of isolates identified correctly by 3%. Other strategies using the API 10S in combination with the API 20E or a deoxyribonuclease test were also evaluated for cost and accuracy.