In a stress test, the recently introduced RapID CB Plus system (Remel Inc. [formerly Innovative Diagnostic Systems], Norcross, Ga.) was challenged with a diverse set of gram-positive rods comprising 345 strains of coryneform bacteria and 33 strains of Listeriaspp. representing a total of 49 different taxa. Overall, within 4 h, the system correctly identified 80.9% of the strains on the species level and 12.2% of the strains on the genus level. Only 3.7% strains were misidentified, and for 3.2% of the strains no identification was provided. Difficulties with the system were mainly due to occasional uncertainties in reading reactions for acid production from carbohydrates and, to a lesser extent, aminopeptidase reactions. It is concluded that the system may also perform well under the conditions of a routine clinical laboratory.

The performance of two enzyme immunoassays for rapid detection of group B streptococci (GBS) was evaluated in comparison to culture using cervical swabs from 191 pregnant women. Ten percent of the women harboured GBS. There were two positive results in the Icon assay (Hybritech), both in women with heavy growth in the culture, and four positive results in the Quidel assay (Quidel), two in the women with heavy colonization and one each in women with moderate and light growth of GBS respectively. The sensitivity of both assays was low, being 11% (2/18) for the Icon assay and 24% (4/17) for the Quidel assay. The specificity of both assays was 100%. Both assays could detect > or = 10(6) group B streptococci per swab. A positive result justifies ampicillin prophylaxis due to the high risk for the newborn. A negative result should be confirmed by rapid culture techniques.