Virulence factors of avian Escherichia coli.
A total of 45 strains of Escherichia coli isolates from chickens with colisepticemia were examined for virulence factors commonly found in pathogenic groups of E. coli. These strains were studied for the following: pathogenicity in 1-day-old chicks; toxin, hemolysin, and colicin production; cell invasiveness and adherence; hemagglutination for fimbriae detection; serum resistance; aerobactin production in iron-limited conditions; and plasmid content. The characteristics exhibited by virulent strains were invasion for HeLa and chicken fibroblast cells, serum resistance, colicin V, and aerobactin production. None of the isolates were toxigenic or positive in hemagglutination tests. The molecular genetic studies of the virulence factors by agarose electrophoresis showed that the plasmids of these strains are of high molecular weight.
Vidotto
M C
MC
Departamento de Patologia Geral, Universidade Estadual de Londrina, Paraná, Brazil.
Müller
E E
EE
de Freitas
J C
JC
Alfieri
A A
AA
Guimarães
I G
IG
Santos
D S
DS
D000372:Agglutination Tests; D000818:Animals; D001422:Bacterial Adhesion; D001427:Bacterial Toxins / Q000096:biosynthesis; D002478:Cells, Cultured; D002645:Chickens; D003087:Colicins / Q000096:biosynthesis; D004269:DNA, Bacterial / Q000032:analysis; D004587:Electrophoresis, Agar Gel; D004768:Enterotoxins / Q000096:biosynthesis; D004926:Escherichia coli / Q000235:genetics / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins; D005347:Fibroblasts / Q000382:microbiology; D006367:HeLa Cells; D006386:Hemagglutination Tests; D006460:Hemolysin Proteins / Q000096:biosynthesis; D010957:Plasmids; D011201:Poultry Diseases / Q000382:microbiology*; D018805:Sepsis / Q000382:microbiology / Q000662:veterinary*; D014774:Virulence
D001427:Bacterial Toxins; D003087:Colicins; D004269:DNA, Bacterial; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; C034151:heat stable toxin (E coli)