The RapID Yeast Plus System (Innovative Diagnostic Systems, Norcross, Ga.) is a qualitative micromethod that uses conventional and chromogenic substrates for the identification of medically important yeasts. The ability of the RapID Yeast Plus system to accurately identify 304 clinical yeast isolates within 5 h was evaluated. The RapID Yeast Plus method correctly identified 286 (94.1%) of strains to the species level without the need for additional tests. A further 12 strains (3.9%) were classified as correct to the genus level or to a lowprobability identification with two or more possibilities. In these latter cases, additional tests were required to delineate the correct identification. Organisms in the latter group comprised Candida parapsilosis (n ‫؍‬ 1), Candida tropicalis (n ‫؍‬ 1), Candida ciferrii (n ‫؍‬ 1), Candida guilliermondii (n ‫؍‬ 2), Candida humicola (n ‫؍‬ 1), Candida kefyr (n ‫؍‬ 1), Cryptococcus neoformans (n ‫؍‬ 1), and Rhodotorula rubra (n ‫؍‬ 4). Six strains (2.0%) were misidentified or did not yield codes in the manufacturer's database. These included one Candida utilis (identified as Candida famata/Candida guilliermondii), one Trichosporon beigelii (identified as Cryptococcus neoformans), one Candida diddensiae (identified as Candida albicans), one Candida membranaefaciens (identified as Candida parapsilosis), one Candida norvegensis (identified as Candida zeylanoides), and one Candida catenulata (no code) isolate; the last four strains are not included in the firm's current database. The RapID Yeast Plus system yielded excellent results and may be recommended for use in the routine laboratory for accurate same-day identification of clinically significant yeasts.

The ATB 32A system (API System SA, La Balme les Grottes, Montalieu-Vercieu, France) was evaluated for use in the identification of 214 anaerobes. Organisms included 73 isolates of the Bacteroidesfragilis group, 24 Bacteroides spp., 10 fusobacteria, 43 clostridia, 28 cocci, and 36 gram-positive, nonsporeforming rods. With the concomitant use of Gram stain, pigmentation, catalase testing, and aerobic growth, the ATB 32A system correctly identified 97% of the B. fragilis group isolates, 88% of Bacteroides spp., 50% of fusobacteria, 74% of clostridia, 100% of cocci, and 86% of the gram-positive, nonsporeforming rods. Overall, 188 strains (88%) were correctly identified, with 18 (8%) requiring extra tests, other than the four mentioned above, for correct identification. Eight strains were misidentified, including one Bacteroides sp., three fusobacteria, one Clostridium sp., and three gram-positive, nonsporeforming rods. Reproducibility was very good, with 12 of 14 strains (86%) tested in triplicate yielding identical correct results on each of three occasions and 2 strains (14%) yielding identical correct results on two occasions. There was a low-probability identification (including the correct species) on the third testing. The ATB 32A system represents a worthwhile advance in systems used for the identification of clinically significant anaerobic bacteria.

The ability of the RapID NF Plus system (Innovative Diagnostic Systems, Inc., Atlanta, Ga.) to identify 345 nonfermentative gram-negative rods was evaluated. Kits were inoculated with no. 1 McFarland suspensions, and reactions were interpreted after a 4-h incubation at 35°C. Overall, the method correctly identified 311 strains (90.1%) without additional tests and 21 strains (6.1%) with additional tests, and 13 strains (3.8%) were misidentified. Five of 13 misidentified strains were Alcaligenes faecalis-Alcaligenes odorans misidentified as Alcaligenes xylosoxidans; however, all strains were xylose negative but nitrate positive and could have been A. faecalis group I-Alcaligenes piechaudii. The system does not differentiate between Pseudomonasfluorescens and Pseudomonasputida, and allAcinetobacter species are identified asAcetinobacter calcoaceticus. Additionally, no subspecies differentiation is made between A. xylosoxidans subsp. xylosoxidans and A. xylosoxidans subsp. denitrificans. All strains of the former Flavobacterium group IIb are identified as Flavobacterium indologenes-Flavobacterium gleum, and no species identification of the genus Methylobacterium is attempted. The system is easy to set up and interpret and provides an accurate commercial nonautomated method for same-day identification of gram-negative nonfermenters.

The ability of the RapID onE system (Innovative Diagnostic Systems, Inc., Norcross, Ga.) to identify 364 strains in the family Enterobacteriaceae and 15 oxidase-negative, gram-negative, nonfermentative rods was evaluated. Kits were inoculated with no. 2 McFarland standard suspensions, and reactions were interpreted after 4 h of incubation at 35 degrees C. Overall, the method correctly identified (to the species level or to the genus level for salmonellas and non-Shigella sonnei Shigella species) 363 strains (95.8%) without additional tests. For four strains (1.0%), additional tests were required to delineate the correct identification from a range of two or more possibilities; these included one Serratia liquefaciens (Serratia marcescens or Serratia liquefaciens), one Serratia rubidaea (Serratia rubidaea or Serratia odorifera), one Salmonella typhi (Leminorella richardii or Salmonella sp.) and one Yersinia enterocolitica (Yersinia frederiksenii, Yersinia intermedia, or Yersinia enterocolitica). Twelve strains (3.2%) were misidentified or yielded codes with no identification; these comprised one Citrobacter amalonaticus (no identification), three Enterobacter hormaechei (not in the RapID onE database; two Enterobacter amnigenus, one Enterobacter sp.), one Serratia liquefaciens (Enterobacter cloacae), one Serratia rubidaea (no identification), four Serratia fonticola (not in RapID onE database; two Enterobacter aerogenes, one Serratia marcescens, one not identified), one Proteus mirabilis (Proteus penneri), and one Proteus vulgaris (Providencia rustigianii). If the seven strains not included in the database had been excluded, correct identification rates would have risen to 97.6% without additional tests and 98.7% with additional tests, with misidentification rates dropping to 1.3%. The RapID onE system is easy to set up and the results are easy to read, and the system provides an accurate, nonautomated commercially available method for the same-day identification of members of the family Enterobacteriaceae and oxidase-negative, gram-negative nonfermenters.