Further differentiation of Enterobacteriaceae by means of siderophore-pattern analysis

By means of a combination of 5 siderophore bioassays using several indicator strains, genera, species and subspecies of Enterobacteriaceae can be further differentiated. Enterobactin, aerobactin and other siderophores produced can be detected. Each strain shows specific pattern which we called siderophore-pattern. It is easy to separate Morganella, Proteus, Providencia, Yersinia strains from the genera Salmonella, Shigella, Escherichia coli, Enterobacter, Citrobacter, Klebsiella, Serratia. Enterobacter agglomerans strains differ from other Enterobacter species with respect to their siderophore pattern. In Salmonella strains there are differences between the subspecies I and IV. Additionally the most strains of Salmonella subspecies I from nosocomial infections produced aerobactin, in the most cases determined by plasmids. Among Shigella strains different siderophore pattern exist according to other epidemiological markers. S. flexneri strains of serovar 6 produced contrary to the strains of other serovars enterobactin. By means of the siderophore-pattern analysis E. coli strains of serovars 01; 02; 018 can be further differentiated. E. coli 01:K1 strains containing the fimbrial antigen F11 produced aerobactin whereas the F9 strains did not. All Hafnia alvei strains produced a uniform siderophore pattern, different from all other members of the enterobacteriaceae family. With this aim Hafnia alvei strains can be easily separated under practical conditions.