Mice vaccinated with enteropathogenic Escherichia coli ghosts show significant protection against lethal challenges.
OBJECTIVE
To prepare enteropathogenic Escherichia coli (EPEC) E2348/69 ghosts and investigate whether immunization with EPEC bacterial ghosts can elicit protective immune responses.


RESULTS
A recombinant plasmid with double λPL/PR-cI857 temperature-sensitive regulatory cassettes was constructed. The lysis gene E and/or the staphylococcal nuclease A (SNA) gene were separately inserted downstream of the two regulatory cassettes to construct the lysis plasmids pBV220::E and pBV220::E::CI-P-SNA. An EPEC reference strain E2348/69 (serotype O127:H6) was transformed with the lysis plasmids to produce EPEC ghosts. Mice injected with bacterial ghosts EGE (EPEC ghosts produced using lysis protein E) or EGES (EPEC ghosts produced using a combination of lysis protein E and SNA) gained weight normally and showed no clinical signs of disease. Vaccination trials showed that mice immunized with EGE or EGES were significantly protected against subsequent challenge with the wild-type virulent parent strain, EPEC E2348/69 (42/50 and 45/50 survival, respectively); in contrast, none of the 30 control mice survived.


CONCLUSIONS
Immunization with EPEC ghosts can elicit protective immune responses in BALB/c mice.


CONCLUSIONS
EPEC ghosts may represent a promising new approach for vaccination against EPEC infection.
Institute of Military Veterinary Science, Academy of Military Medical Sciences, Changchun, China.
J
J
Liu
W D
WD
Wang
Y J
YJ
Liu
S
S
Liu
B
B
Zhou
L W
LW
Zhu
X
X
Ji
Y
Y
Sun
S Z
SZ
Feng
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001428:Bacterial Vaccines / Q000276:immunology* / Q000382:microbiology; D054308:Enteropathogenic Escherichia coli / Q000276:immunology* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000276:immunology / Q000517:prevention & control*; D005260:Female; D005822:Genetic Vectors; D007074:Immunoglobulin G / Q000097:blood; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids; D014774:Virulence
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D007074:Immunoglobulin G