Open AccessIron utilization studies in Citrobacter species
Author(s) -
Shideh Khashe J.,
Janda Michael
Publication year - 1996
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1996.tb08096.x
Subject(s) - aerobactin , siderophore , citrobacter , microbiology and biotechnology , hemin , virulence , bacteria , enterobactin , chemistry , biology , enterobacteriaceae , biochemistry , heme , escherichia coli , gene , enzyme , genetics
Seventy‐one strains of Citrobacter were screened for iron scavenging mechanisms by biologic and chemical assays. Essentially all citrobacteria (70 / 71) were found to elaborate enterobactin‐like siderophores by both biologic and chemical assays, however only C. koseri (C. diversus) was found to produce aerobactin. The concentration of ethylenediamine di( o ‐hydroxyphenylacetic acid) (EDDA) required to inhibit the growth of individual Citrobacter strains by depleting free iron ranged from 250 μg/ml to 1000 μg/ml. Iron utilization studies of selected Citrobacter isolates indicated that hemin and hematin could reverse the effects of iron limitation on growth under iron‐stressed conditions (1000 μg/ml of EDDA). Two C. koseri strains grown under iron‐restricted conditions showed similar changes in their whole cell protein profiles including induction of high molecular mass proteins (72–83 kDa) which may play a role in iron acquisition under iron‐stressed conditions. The collective results support an additional virulence‐associated mechanism for C. koseri strains which may help explain the greater pathogenic potential this group has for causing serious extraintestinal disease in humans.