Experimental enteric infection of gnotobiotic piglets with a Chlamydia psittaci strain of avian origin.
The pathogenicity of a Chlamydia psittaci isolate of pigeon origin was assessed using a litter of gnotobiotic piglets. At 3 days of age, six piglets were inoculated intragastrically with egg-grown chlamydiae, the remaining six pigs were sham-inoculated. The animals were observed for clinical signs, and they were killed and necropsied sequentially between 4 and 15 days of age. Clinical manifestations consisted of slight softening of the faeces between 6 and 10 days post-inoculation (DPI). Immunohistochemistry revealed chlamydial replication predominantly in the small intestine, initially within villous enterocytes, after 4 DPI mostly in the lamina propria. Histopathology showed villous atrophy and increased numbers of inflammatory cells in the gut up to 6 DPI. Chlamydial stages of normal morphology were identified within enterocytes using transmission electron microscopy. An enzyme-linked immunosorbent assay (ELISA) run on faecal samples revealed shedding of chlamydial antigen from 3 until 11 DPI. Systemic dissemination of Chlamydia occurred to a limited extent according to polymerase chain reaction and immunohistochemistry results of several extraintestinal organs. Corresponding histopathological changes were minimal. Sera of all pigs were negative for anti-chlamydial antibodies using a complement fixation test. In conclusion, inoculation of this isolate in gnotobiotic piglets resulted in a productive enteric infection with mild lesions, weak systemic dissemination, and faecal shedding, indicating the pig as a potential host for avian chlamydiae.
Guscetti
F
F
Institute of Veterinary Pathology, University of Zurich, Switzerland.
Hoop
R
R
Schiller
I
I
Corboz
L
L
Sydler
T
T
Pospischil
A
A
D000818:Animals; D000831:Animals, Newborn; D000942:Antigens, Bacterial / Q000302:isolation & purification; D001715:Bird Diseases / Q000382:microbiology; D002691:Chlamydophila psittaci / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*; D010856:Columbidae / Q000382:microbiology; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005243:Feces / Q000382:microbiology; D005767:Gastrointestinal Diseases / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D005856:Germ-Free Life; D007150:Immunohistochemistry / Q000662:veterinary; D007421:Intestine, Small / Q000382:microbiology / Q000648:ultrastructure; D008854:Microscopy, Electron / Q000662:veterinary; D016133:Polymerase Chain Reaction / Q000662:veterinary; D009956:Psittacosis / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology* / Q000473:pathology*
D000942:Antigens, Bacterial