Pseudomonas
is a large and complex genus of Gram‐negative bacteria that is important because it includes species with both clinical and environmental implications.
Pseudomonas
spp. are conventionally described as aerobic species based on their growth in routine media used in the clinical microbiology laboratory, but several species are actually facultative aerobes. The identification of fluorescent and nonfluorescent pseudomonads has become less difficult with the availability of MALDI‐TOF MS technology, which has replaced conventional phenotypic identification systems in many clinical microbiology laboratories. However, phenotypic methods are still used in small laboratories, and it should be recognized that these methods also provide information about the physiological and biochemical capabilities of the bacteria, which may sometimes be important for the pathogenesis of infections. The frequent acquisition of antimicrobial resistance in
P. aeruginosa
limits the utility of antimicrobial susceptibility patterns as a tool in epidemiological typing.