Background:The accurate and rapid identification (ID) of nonfermentative gram-negative bacilli (NFB) is essential for diagnostic and therapeutic purposes and for epidemiologic studies of hospital infections. Commercial identification systems of NFB are easy to use but too expensive. The aim of the study was to develop a simple system for the identification of NFB species which are frequently isolated from clinical specimens.

Methods:Eighteen biochemical tests used in NFB microplate ID system were pyocyanin in Tech media; pyoverdin in Flo media; glucose fermentation, acid formation from glucose, maltose, lactose, sucrose, and mannitol in oxidation-fermentation media; Nitrate and nitrite reduction in nitrate media; ornithine decarboxylase, lysine decarboxylase, and arginine dihydrolase in Moeller decarboxylase media; acetamide, urease, citrate, 42℃growth, and oxidase test. For the establishment of NFB’s biochemical data in microplate ID system, 175 consecutive isolates of NFB from clinical specimens isolated during the period of April 2000 were simultaneously tested by microplate method and API 32GN.

Results:Ninety-two percent of clinical isolates of NFB were identified to the species level by NFB microplate ID system.

Conclusions: The NFB microplate ID system is simple to use, rapid and economical. Further modification are needed to improve the accuracy and identification rate of NFB isolates. (Korean J Clin Microbiol 2002;5(1):26-34)