title: Oral Uptake of Chlamydia psittaci by Ducklings Results in Systemic Dissemination.
abstract: Enteric infections caused by Chlamydia (C.) psittaci are frequent in ducks, but mostly remain subclinical under field conditions. To emulate natural infection, we investigated the pathogenic potential of a C. psittaci field strain in orally inoculated 4-day-old ducklings. Three different challenge doses were tested and seven contact animals were also mock-inoculated with buffer in each group. Over the course of ten days, the birds were monitored for clinical symptoms and chlamydial dissemination before final examination of tissues using histopathology and immunohistochemistry. While the challenge strain disseminated systemically to all internal organs, mild signs of diarrhea were confined to ducklings inoculated with the highest dose (4.3 x 108 IFU/mL, Group 1). No other clinical symptoms or histopathological lesions were seen. The chlamydial load in internal organs as measured by PCR depended on the challenge dose and was unevenly distributed, i.e. high loads in spleen, liver, and distal small and large intestinal tract (ileum, cecum and rectum) vs. ten times lower values in lungs and proximal small intestinal tract (duodenum and jejunum). Notably, the C. psittaci infection of contact birds became evident on day 10 post-infection, with bacterial loads comparable to those of experimentally-infected animals, thus suggesting rapid bird-to-bird transmission of the challenge strain.
authors.affiliation: ANSES, Animal Health Laboratory, Bacterial Zoonoses Unit, Maisons-Alfort, France.
authors.forename: Simon
authors.initials: S
authors.lastname: Thierry
authors.affiliation: ANSES, Animal Health Laboratory, Bacterial Zoonoses Unit, Maisons-Alfort, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Vorimore
authors.affiliation: INRA, UMR1282 Infectiology and Public Health, Nouzilly, France.|UMR1282 Infectiology and Public Health, François Rabelais University, Tours, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Rossignol
authors.affiliation: Friedrich-Loeffler-Institut (Federal Research Institute for Animal Health), OIE Reference Laboratory for Chlamydiosis, Jena, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Scharf
authors.affiliation: Friedrich-Loeffler-Institut (Federal Research Institute for Animal Health), OIE Reference Laboratory for Chlamydiosis, Jena, Germany.
authors.forename: Konrad
authors.initials: K
authors.lastname: Sachse
authors.affiliation: INRA, UMR1282 Infectiology and Public Health, Nouzilly, France.|UMR1282 Infectiology and Public Health, François Rabelais University, Tours, France.
authors.forename: Patricia
authors.initials: P
authors.lastname: Berthon
authors.affiliation: ANSES, Animal Health Laboratory, Epidemiology Unit, Maisons-Alfort, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Durand
authors.affiliation: INRA, UMR1282 Infectiology and Public Health, Nouzilly, France.|UMR1282 Infectiology and Public Health, François Rabelais University, Tours, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Virlogeux-Payant
authors.affiliation: Institute of Veterinary Pathology, University of Zurich-Vetsuisse, Zurich, Switzerland.
authors.forename: Nicole
authors.initials: N
authors.lastname: Borel
authors.affiliation: ANSES, Animal Health Laboratory, Bacterial Zoonoses Unit, Maisons-Alfort, France.
authors.forename: Karine
authors.initials: K
authors.lastname: Laroucau
mesh_terms: D000818:Animals; D058491:Bacterial Load; D002691:Chlamydophila psittaci / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D004372:Ducks / Q000382:microbiology*; D007150:Immunohistochemistry; D009928:Organ Specificity; D009956:Psittacosis / Q000382:microbiology / Q000473:pathology / Q000635:transmission* / Q000662:veterinary*