Cellular fatty acids and metabolic products of Pseudomonas species obtained from clinical specimens

Abstract

The cellular fatty acid composition of 112 reference strains and clinical isolates of Pseudomonas spp. was determined by GLC. The presence and relative amounts of cyclopropane, hydroxy and branched-chain fatty acids were distinguishing features of these strains. Determination of short-chain fatty acids extracted from spent growth media provided an additional means for identifying some strains. Clinical isolates of pseudomonads can apparently be divided into 8 distinct GLC groups. The procedures were especially useful for distinguishing glucose-nonoxidizing pseudomonads, which are difficult to identify by conventional criteria. Since the GLC procedures are simple, rapid and highly reproducible, they are useful in diagnostic laboratories that process large numbers of cultures. Coupled with selected conventional tests, the analysis of short-chain and cellular fatty acids can be very useful for rapid screening of clinical isolates of Pseudomonas spp.