Avian- and mammalian-derived antibodies against adherence-associated proteins inhibit host cell colonization by Escherichia coli O157:H7.
OBJECTIVE
To evaluate the potential for polyclonal antibodies targeting enterohaemorrhagic Escherichia coli (EHEC) virulence determinants to prevent colonization of host cells by E. coli O157:H7.


RESULTS
Rats and laying hens were immunized with recombinant proteins from E. coli O157:H7, EspA, C-terminal intimin or EscF. Rat antisera (IgG) or chicken egg powders (IgY) were assessed for their ability to inhibit growth and colonization-associated processes of E. coli O157:H7. Mammalian antisera with antibodies to intimin, EspA or EscF effectively reduced adherence of the pathogen to HeLa cells (P<0.05) and prevented type III secretion of Tir. Similarly, HeLa cells treated with chicken egg powder containing antibodies against intimin or EspA were protected from EHEC adherence (P<0.05). Neither egg nor rat antibody preparations had any antibacterial effect on the growth of EHEC (P>0.05).


CONCLUSIONS
Antibody preparations targeting EHEC adherence-associated factors were effective at preventing adhesion and intimate colonization-associated events.


CONCLUSIONS
This work indicates that immunotherapy with anti-adherence antibodies can reduce E. coli O157:H7 colonization of host cells. Passive immunization with specific antibodies may have the potential to reduce E. coli O157:H7 colonization in hosts such as cattle or humans.
Cook
S R
SR
Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, AB, Canada, and Nutratech Inc., Winnipeg, MB, Canada.
Maiti
P K
PK
DeVinney
R
R
Allen-Vercoe
E
E
Bach
S J
SJ
McAllister
T A
TA
D018829:Adhesins, Bacterial / Q000276:immunology; D000818:Animals; D001422:Bacterial Adhesion / Q000276:immunology*; D002645:Chickens; D003598:Cytoskeletal Proteins / Q000276:immunology; D019453:Escherichia coli O157 / Q000254:growth & development / Q000276:immunology / Q000472:pathogenicity*; D029968:Escherichia coli Proteins / Q000276:immunology*; D005260:Female; D006367:HeLa Cells; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D007116:Immunization, Passive / Q000379:methods*; D010063:Ovum / Q000276:immunology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins / Q000276:immunology; D014774:Virulence / Q000276:immunology
D018829:Adhesins, Bacterial; D003598:Cytoskeletal Proteins; C446619:EscF protein, E coli; D029968:Escherichia coli Proteins; C102051:EspA protein, E coli; D007106:Immune Sera; D011993:Recombinant Fusion Proteins; C073819:eaeA protein, E coli