Epidemiology of aerobactin production in Enterobacteriaceae

Clinical isolates (496) of 10 different enterobacterial genera were studied for aerobactin excretion, colicin production and antibiotic resistance. In the case of Escherichia coli, the incidence of aerobactin-positive strains in 108 blood isolates (45%) was not significantly different from that corresponding to faecal sources (41%). Although colicin V production was much more frequently associated with aerobactin production than other colicins, colicin V was only produced by 26% of aerobactin excreters. Some strains were aerobactin-negative and colicin V producers. Aerobactin production seemed to be significantly associated with plasmidic antibiotic resistance. The production of the siderophore is described for the first time in Proteus, Serratia and Morganella strains.