The iron uptake systems of Plesiomonas shigelloides strains were determined. Siderophore production was not detected by chemical or biological assays, and the strains tested were unable to use enterobactin, aerobactin, or vibriobactin for growth in low-iron media. Both hemin and hemoglobin supported full growth of the bacteria in media lacking other iron sources, but neither transferrin nor lac...

To evaluate the role of aerobactin production in the virulence of Shigella flexneri, a iuc::Tn10 insertion mutant was obtained from strain M90T, a serotype 5 isolate. This mutant was tested for its ability to invade and kill HeLa cells in monolayers, to elicit keratoconjunctivitis in guinea pigs and to infect ligated segments of rabbit ileal loops. Although this mutant did not grow in iron-depl...

The molecular mechanisms that define asymptomatic bacteriuria (ABU) Escherichia coli colonization of the human urinary tract remain to be properly elucidated. Here, we utilize ABU E. coli strain 83972 as a model to dissect the contribution of siderophores to iron acquisition, growth, fitness, and colonization of the urinary tract. We show that E. coli 83972 produces enterobactin, salmochelin, a...

We aimed to evaluate the potential virulence of Klebsiella isolates from enteral diets in hospitals, to support nosocomial infection control measures, especially among critical-care patients. Phenotypic determination of virulence factors, such as capsular expression on the external membrane, production of aerobactin siderophore, synthesis of capsular polysaccharide, hemolytic and phospholipase ...

In this study we sequenced and analysed the fimH and fimA genes of 24 avian pathogenic Escherichia coli (APEC) isolates, in order to investigate their possible conserved nature. Additional parameters (serotype, presence of aerobactin receptor, expression of F1 pili and virulence for chickens) were investigated to look for correlations with the obtained sequences. The sequence analysis demonstra...

Possession of P fimbriae, virulence-associated O and K antigens, haemolysin and aerobactin production, and susceptibility to 10 antimicrobial agents were studied in 63 Escherichia coli strains isolated from blood or CSF of infants who were grouped according to their clinical characteristics. These isolates were compared with 35 faecal E. coli strains from healthy infants. Individual virulence f...

Pseudomonas spp. have the capacity to utilize siderophores produced by diverse species of bacteria and fungi, and the present study was initiated to determine if siderophores produced by rhizosphere microorganisms enhance the levels of iron available to a strain of Pseudomonas putida in this natural habitat. We used a previously described transcriptional fusion (pvd-inaZ) between an iron-regula...