Serum resistance and aerobactin iron uptake in avian Escherichia coli mediated by conjugative 100-megadalton plasmid.
A total of 115 strains of Escherichia coli isolated from chickens with colisepticemia in Japan were examined for chicken lethality and virulence factors. It was found that serum resistance and aerobactin-mediated iron uptake are the most prevalent characteristics in these strains. Among them, S-20, a representative virulent strain of serotype O2, was further studied. S-20 harbored a conjugative 100-megadalton (Mdal) plasmid, designated pKI100. Curing and reintroduction experiments showed that pKI100 encodes both serum resistance and aerobactin-mediated iron uptake, and the diminished virulence of the pKI100-cured strain was fully restored by the reintroduction of the plasmid. These results demonstrated that pKI100 is the virulence plasmid of the S-20 strain, and that serum resistance and aerobactin-mediated iron uptake are the virulence factors in E. coli strains which cause avian colibacillosis.
Ike
K
K
Research Center for Veterinary Science, Kitasato Institute, Chiba, Japan.
Kawahara
K
K
Danbara
H
H
Kume
K
K
D000818:Animals; D002645:Chickens / Q000276:immunology / Q000382:microbiology*; D004926:Escherichia coli / Q000276:immunology / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000276:immunology / Q000401:mortality / Q000662:veterinary*; D006877:Hydroxamic Acids / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D010957:Plasmids; D011201:Poultry Diseases / Q000276:immunology / Q000382:microbiology* / Q000401:mortality; D017262:Siderophores / Q000502:physiology; D014774:Virulence
D006877:Hydroxamic Acids; D017262:Siderophores; C031819:aerobactin; D007501:Iron