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Chapter 4.8 : Rapid Enzymatic Systems for the Identification of Anaerobes
Rapid identification of anaerobes can be accomplished with commercially available microsystems that detect preformed enzymes within a few hours, eliminating the need for growth of the isolates ( 1 – 4 , 6 – 9 , 12 – 14 , 16 ). The systems that are available are listed in Table 4.8-1 . In a study that recently surveyed what methods laboratories were using to identify isolated anaerobes, 66% reported using a system that detected preformed enzymes ( 5 ). The systems listed in Table 4.8-1 require only 4 h of aerobic incubation after inoculation with a turbid suspension of the organism equivalent to a no. 3 or 4 McFarland standard. There are differences in the numbers and types of organisms included in each database as well as in the substrates that are used for differentiation. Some use fluorogenic and some use chromogenic substrates. Most require some reagent addition after incubation, before reading. Database and numerical identification profiles are provided for each system.