TY - JOUR
T1 - Variations in virulence of avian pathogenic Escherichia coli demonstrated by the use of a new in vivo infection model
AU - Pors, Susanne Elisabeth
AU - Olsen, Rikke Heidemann
AU - Christensen, Jens Peter
N1 - Copyright © 2014 Elsevier B.V. All rights reserved.
PY - 2014
Y1 - 2014
N2 - Salpingitis and peritonitis are common pathological manifestations observed in egg-laying hens. To improve methods to study these conditions, a surgical model was developed. Initially, eighteen white layers underwent laparotomy with subsequent inoculation of ink, bacteria or sterile broth directly into the oviduct. Eight birds inoculated with 0.1 ml blue ink were euthanized immediately after inoculation and the specific site of inoculation was assessed. In all birds, ink was injected into the oviduct between five and seven cm cranial to the isthmus. To demonstrate the use of this approach to cause infection of the oviduct, five birds were inoculated with 8.6 × 10(6)CFU of a clinical Escherichia coli isolate. Five control birds received broth with no bacteria. Both infected and control birds were euthanized after 48 h followed by a post mortem examination. Infected birds showed diffuse fibrino-purulent peritonitis, E. coli was found in pure culture from one or more positions in the oviduct and the liver. Birds receiving sterile broth did not culture positive and demonstrated no gross lesions. Subsequently, 19 birds were inoculated with an isolate of E. coli ST95 and 20 birds with an isolate of E. coli ST141. Major variation in virulence was observed between the two isolates used in relation to clinical signs, gross lesions and histopathology. In contrast to E. coli ST141, E. coli ST95 caused severe clinical signs, epithelial necrosis of the oviduct and purulent salpingitis. The results of the study show the potential of the model in studies of the pathogenesis of infections and virulence of bacteria of the oviduct.
AB - Salpingitis and peritonitis are common pathological manifestations observed in egg-laying hens. To improve methods to study these conditions, a surgical model was developed. Initially, eighteen white layers underwent laparotomy with subsequent inoculation of ink, bacteria or sterile broth directly into the oviduct. Eight birds inoculated with 0.1 ml blue ink were euthanized immediately after inoculation and the specific site of inoculation was assessed. In all birds, ink was injected into the oviduct between five and seven cm cranial to the isthmus. To demonstrate the use of this approach to cause infection of the oviduct, five birds were inoculated with 8.6 × 10(6)CFU of a clinical Escherichia coli isolate. Five control birds received broth with no bacteria. Both infected and control birds were euthanized after 48 h followed by a post mortem examination. Infected birds showed diffuse fibrino-purulent peritonitis, E. coli was found in pure culture from one or more positions in the oviduct and the liver. Birds receiving sterile broth did not culture positive and demonstrated no gross lesions. Subsequently, 19 birds were inoculated with an isolate of E. coli ST95 and 20 birds with an isolate of E. coli ST141. Major variation in virulence was observed between the two isolates used in relation to clinical signs, gross lesions and histopathology. In contrast to E. coli ST141, E. coli ST95 caused severe clinical signs, epithelial necrosis of the oviduct and purulent salpingitis. The results of the study show the potential of the model in studies of the pathogenesis of infections and virulence of bacteria of the oviduct.
KW - Animals
KW - Bacterial Load
KW - Chickens
KW - Escherichia coli
KW - Escherichia coli Infections
KW - Female
KW - Oviducts
KW - Poultry Diseases
KW - Species Specificity
KW - Faculty of Health and Medical Sciences
KW - Egg-laying hens
KW - Infection model
KW - Salpingitis-peritonitis
KW - Escherichia coli
KW - Virulence
U2 - 10.1016/j.vetmic.2014.02.043
DO - 10.1016/j.vetmic.2014.02.043
M3 - Journal article
C2 - 24703749
SN - 0378-1135
VL - 170
SP - 368
EP - 374
JO - Veterinary Microbiology
JF - Veterinary Microbiology
IS - 3-4
ER -