Plasmid pABN1 contains the genetic determinants for the aerobactin iron uptake system of plasmid ColV-K30. Transposon Tn1000 mutants of pABN1 defective in synthesis of a 50,000-dalton polypeptide were found neither to secrete nor to accumulate aerobactin, but were not impaired in iron transport functions, clearly indicating a role for this polypeptide in aerobactin biosynthesis. RNA-DNA hybridi...

The genetic determinants for the aerobactin iron uptake system of plasmid ColV-K30, cloned as recombinant plasmid pABN1, were mapped by insertional inactivation using Tn1000 (gamma delta). Sites of insertion resulting in loss of aerobactin biosynthesis spanned ca. 5.5 kilobase pairs of cloned ColV-K30 DNA contiguous with a 2-kilobase-pair region in which transposon insertion resulted in loss of...

We examined the presence of two virulence factors in 241 blood isolates of Klebsiella pneumoniae from patients hospitalized during 1989 and 1990 in 7 French hospitals, and 125 blood isolates of Escherichia coli from one hospital. Aerobactin was scored phenotypically and genotypically with an intragenic DNA probe of 2 kb. The mucoid phenotype was assessed by culture on trypticase soy agar and by...

The high-affinity iron assimilation system of plasmid ColV-K30 was cloned on the vector plasmid pPlac. Plasmid pABN1 was isolated by means of sensitivity to cloacin, a bacteriocin using the same outer membrane receptor as ferric aerobactin. Restriction maps were determined for this plasmid and for a subclone, pABN5. Plasmid pABN1 codes for the complete gene complex, whereas plasmid pABN5 encode...

BACKGROUND AND OBJECTIVE: Escherichia-coli is one of the major causes of urinary tract infection (UTI). The strains of this bacterium have a variety of virulence factors, such as iron acquisition systems, that provide the energy for iron transport in bacterial membranes. This study aimed to determine the frequency of pathogenic Aerobactin genes among the UTI-causing strains of E. coli isolated ...

Kinetics of radioactive iron transport from three structurally different secondary hydroxamate-iron chelates (schizokinen-iron, produced by Bacillus megaterium ATCC 19213; Desferal-iron, produced by an actinomycete; and aerobactin-iron, produced by Aerobacter aerogenes 62-1) revealed that B. megaterium SK11 (a mutant which cannot synthesize schizokinen) has a specific transport system for utili...

Aerobactin genes are known to be present in virulent strains and absent from avirulent strains, but contributions of iucC and iucA, which are involved in aerobactin synthesis, to the pathogenicity of avian pathogenic Escherichia coli (APEC) have not been clarified. In this study, effects of double mutants (iucA/iutA or iucC/iutA) compared to those of single mutants (iucA, iucC or iutA) of aerob...

From January to December 2006, 92 Escherichia coli isolates from 25 diarrheic dogs were analyzed by screening for the presence of adhesin-encoding genes (pap, sfa, afa), hemolysin and aerobactin genes. Virulence gene frequencies detected in those isolates were: 12% pap, 1% sfa, 10% hemolysin and 6.5% aerobactin. Ten isolates were characterized as extraintestinal pathogenic E. coli (ExPEC) strai...