Verotoxin-producing Escherichia coli (VTEC) and eae-positive non-VTEC in 1-30-days-old diarrhoeic dairy calves.
Faecal samples from 221, 1-30-days-old, diarrhoeic dairy calves were screened for the presence of verotoxin-producing Escherichia coli (VTEC) and eae-positive non-VTEC. Calves were grouped according to their age (1-7, 8-14, 15-21 and 22-30 days) and analyses of prevalences were done by Mantel-Haenzsel chi 2-test for trend. VTEC and eae-positive non-VTEC were detected in 20 (9.0%) and 18 (8.1%) of the diarrhoeic calves, respectively. A significant age-associated increase in the prevalence of VTEC (p = 0.0001), but not in the prevalence of eae-positive non-VTEC (p = 0.381), was found. Significant differences in VTEC prevalence were found between the age-group 22-30 days and in all other age-groups. 43 (5.0%) of the 861 E. coli isolates from the 221 diarrhoeic calves were VTEC, and 30 (69.8%) of these strains produced VT1 only. More than one-half of the VTEC strains (55.8%) were positive for the eae gene and all these eae-positive VTEC strains produced VT1 only. A high percentage (76.7%) of VTEC strains belonged to E. coli serogroups (O4, O26, O39, O91, O113, O128 and O145) associated with haemorrhagic colitis and haemolytic uraemic syndrome in humans. 51 (5.9%) of the E. coli strains studied were eae-positive non-VTEC and the serogroups most prevalent among these strains were O4, O14, O26 and O123. Only four of the eae-positive strains were also espB-positive by hybridization with a probe from a human EPEC isolate and none of these strains produced VT.
Orden
J A
JA
Departamento Patología Animal I, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain.
Ruiz-Santa-Quiteria
J A
JA
Cid
D
D
García
S
S
Sanz
R
R
de la Fuente
R
R
D018829:Adhesins, Bacterial; D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001427:Bacterial Toxins / Q000096:biosynthesis*; D002352:Carrier Proteins; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology*; D002522:Chlorocebus aethiops; D003967:Diarrhea / Q000382:microbiology / Q000662:veterinary*; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D016133:Polymerase Chain Reaction; D022622:Shiga Toxin 1; D014709:Vero Cells
D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001427:Bacterial Toxins; D002352:Carrier Proteins; C087863:EaeB protein, E coli; D029968:Escherichia coli Proteins; D022622:Shiga Toxin 1; C073819:eaeA protein, E coli