Aerobactin production of serotyped Escherichia coli from urinary tract infections

Aerobactin production was examined by a bioassay in 467 Escherichia coli urinary strains from girls. All strains were of known O:K:H serotype. 139, 119 and 112 strains were isolates from pyelonephritis (Py), cystitis (Cy) and asymptomatic bacteriuria (ABU), respectively, and 97 were from fecal samples of healthy girls (FN). The incidence of aerobactin production was significantly higher among Py strains than among ABU and FN strains (P less than 0.001) and also significantly higher than among Cy strains (P less than 0.01). Aerobactin production was associated with serotype, e.g. the majority of O6:K2:H1 strains and of O16:K1:H6 were positive while e.g. the O6:K13:H1 strains were negative. There was no consistent pattern of coappearance of aerobactin and hemolysin.