Correlation between human lactoferrin binding and colicin susceptibility in Escherichia coli.
Escherichia coli H10407 demonstrated low 125I-human lactoferrin (HLf) binding (7%) and was insusceptible to group A (A, E1, E2, E3, E6, and K) and group B (B, D, Ia, Ib, and V) colicins. Conversely, a spontaneous HLf high-binding (44%) variant, H10407(Lf), demonstrated an increase susceptibility to both colicin groups. Colicin-insusceptible E. coli wild-type strains 75ColT, 84ColT, and 981ColT showed a low degree of HLf binding, i.e., 4, 8, and 10%, respectively. The HLf binding capacity was high in the corresponding colicin-susceptible mutants 75ColS (43%), 84ColS (32%), and 981ColS (43%). Furthermore, HLf low- (less than 5%) and high- (greater than 35%) binding E. coli clinical isolates (10 in each category) were tested for susceptibility against 11 colicins. Colicin V susceptibility did not correlate with HLf binding in either categories. However, with the remaining colicins, three distinct HLf-binding, colicin susceptibility patterns were observed; (i) 10 of 10 HLf low-binding strains were colicin insusceptible, (ii) 6 of 10 HLf high-binding strains were also colicin insusceptible, and (iii) the remaining HLf high binders were highly colicin susceptible. Certain proteins in the cell envelope and outer membrane of wild-type H10407 (HLf low binder, colicin insusceptible) showed a lower mobility in sodium dodecyl sulfate-polyacrylamide gel electrophoresis compared to the corresponding proteins of mutant H10407(Lf) (HLf high binder, colicin susceptible). These mobility differences were also associated with HLf-binding proteins in Western blot (ligand blot) analysis. The wild type showed a smooth form of lipopolysaccharide (LPS) with a distinct ladder of O-chains, compared to the rough LPS of the mutant.(ABSTRACT TRUNCATED AT 250 WORDS)
Gadó
I
I
Department of Medical Microbiology, Malmö General Hospital, University of Lund, Sweden.
Erdei
J
J
Laszlo
V G
VG
Pászti
J
J
Czirók
E
E
Kontrohr
T
T
Tóth
I
I
Forsgren
A
A
Naidu
A S
AS
D015153:Blotting, Western; D003087:Colicins / Q000378:metabolism*; D004198:Disease Susceptibility; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D006801:Humans; D007781:Lactoferrin / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000378:metabolism
D003087:Colicins; D008070:Lipopolysaccharides; D007781:Lactoferrin