Clinical evaluation of the rapid carbohydrate degradation microtube method for identification of Neisseria species

Abstract

The rapid carbohydrate degradation (Carr Microbiologicals Wichita, Kans.) microtube method is a new test system designed for the identification of Neisseria spp. The system consists of four microtubes containing different carbohydrates in a peptone-Bitone basal medium. This method was evaluated for accuracy and speed in identifying species of Neisseria. Of the 386 clinical isolates used in this study, 98.4% were correctly identified to species level in 4 h with the rapid carbohydrate degradation system; parallel testing of the same isolates with conventional cystine-tryptic agar resulted in 96.1% accuracy in 48 h.

Rapid confirmatory identification of Neisseria gonorrhoeae with lectins and chromogenic substrates

“…Thus, the genes for maltose degradation and GGA are apparently not closely linked genetically, and isolates with an aberrant maltose reaction may be identified by testing for GGA activity. The commonly used rapid carbohydrate degradation methods for identifying Neisseria species require a 4to 5-h incubation period (10,13,17). Yong and Prytula (17) identified within 4 h all 377 strains of N. gonorrhoeae tested by using a rapid microcarbohydrate method.…”

“…The identification of Neisseria gonorrhoeae, Neisseria meningitidis, and other Neisseria species in the clinical laboratory is usually accomplished by culture and the performance of carbohydrate degradation tests (17). In the cystine tryptic agar method, incubation and growth of the organism for 24 to 48 h is required before acid production can be detected (11,13,17). The reported reliability of the cystine tryptic agar method for the identification of N. gonorrhoeae ranges from 73.1 to 98.6% (1,12,16).…”

Difficulties in differentiating Neisseria cinerea from Neisseria gonorrhoeae in rapid systems used for identifying pathogenic Neisseria species

“…cinerea strains were not included in early evaluations of the BACTEC system or other Neisseria identification methods that are based on radiometric or spectrophotometric detection of CO2 produced from sugars (9, 28). Similarly, published reports dealing with tests based on rapid carbohydrate utilization (2, 3, 7, 13, 15, 17, 21-25, 27, 28, 32-35), detection of enzymes such as PRO and gammaglutamylaminopeptidase (10,13,26,32,33), or coagglutination (1,3,4,8,11,15,20,24,26) have not described any results for N. cinerea.…”

Evaluation of a one-hour test for the identification of Neisseria species

“…In addition, it identified isolates in only 1 h, as opposed to 24 to 48 h for the CTA method. DISCUSSION Most rapid carbohydrate degradation methods for identifying Neisseria species require a 4-to 5-h incubation period (2,3,7,8,12,16,18,20). Although some studies indicate that a portion of the isolates can be identified within 1 h, this represents only a small percentage of the strains tested (20).…”

“…and B. catarrhalis often requiring 48 h for completion (7,11), rapid modifications of this method which eliminate the requirement for growth during the test procedure have been introduced. The identification of an isolate by these methods usually requires at least 4 h of incubation (3,7,11,12,16,18,20). A more rapid and reliable method for identifying these organisms is provided by the RIM-N kit (Austin Biological Laboratories, Inc., Austin, Tex.).…”