title: Pathogenicity of low and highly virulent Chlamydia psittaci isolates for specific-pathogen-free chickens.
abstract: In commercially raised poultry, chlamydiosis mostly seems to occur on turkey or duck farms, sometimes associated with zoonotic transmission and disease (psittacosis) in humans. However, Chlamydia infections are apparently emerging in chickens, and information on the virulence of Chlamydia in chickens is limited. Up-to-date Chlamydia psittaci genotypes B and D are most frequently found in broilers. We examined the pathogenicity of the well-characterized C. psittaci genotype B (CP3) and D (92/1293) strains in experimentally (aerosol) infected specific-pathogen-free chickens. Both strains caused conjunctivitis, rhinitis, and dyspnea. Pharyngeal and cloacal C. psittaci excretion was observed in all infected animals, indicative for systemic dissemination as proven by immunofluorescence staining of frozen tissue sections. Histopathologic lesions were present in all infected chickens. However, differences in pathology were observed. Genotype D led to mortality and more severe clinical signs and lesions as compared to genotype B, which showed lower virulence.
authors.forename: Lizi
authors.initials: L
authors.lastname: Yin
authors.forename: Stefanie
authors.initials: S
authors.lastname: Lagae
authors.forename: Isabelle
authors.initials: I
authors.lastname: Kalmar
authors.forename: Nicole
authors.initials: N
authors.lastname: Borel
authors.forename: Andreas
authors.initials: A
authors.lastname: Pospischil
authors.forename: Daisy
authors.initials: D
authors.lastname: Vanrompay
mesh_terms: D000818:Animals; D002645:Chickens; D002691:Chlamydophila psittaci / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D005243:Feces / Q000382:microbiology; D005455:Fluorescent Antibody Technique / Q000662:veterinary; D011201:Poultry Diseases / Q000382:microbiology* / Q000473:pathology; D009956:Psittacosis / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D013047:Specific Pathogen-Free Organisms; D014774:Virulence