Conventional Methods
The physical and biochemical properties of Legionella spp. are listed in Box 19-2.However, biochemical testing has limited value in the presumptive identification of isolates to the species level. The confirmation of the suspected colonies and their presumptive identification as Legionella spp. can be achieved in the microbiology laboratory using growth requirement for L-cysteine testing, Gram stain, and DFAtests (Figure 19-30).The confirmation of the suspected colonies and their presumptive