title: New insights on infectious bronchitis virus pathogenesis: characterization of Italy 02 serotype in chicks and adult hens.
abstract: Infectious bronchitis (IB) is a worldwide disease affecting chickens of all ages and causing important economic losses in poultry industry. Despite being one of the predominant IB virus (IBV) serotype in several European countries, slightly is known about pathogenesis and pathogenicity of Italy 02 serotype. In this study chicks and old hens were infected by oculo-nasal route with Italy 02 serotype. Clinical signs, gross and microscopic findings were evaluated, viral nucleic acid detection was assessed by in situ hybridization (ISH) in several tissues and viral RNA was detected by RT-PCR in trachea, kidney and nasal and cloacal swabs. Italy 02 serotype was demonstrated to cause severe respiratory and renal damage in one-day old chicks but not in adult hens in which only respiratory disease and drop in egg production was observed. The use of ISH technique demonstrated the presence of viral RNA in nasal turbinates prior to trachea, but more consistent and longer replication periods in enterocytes of lower gastrointestinal tract. The detection of viral nucleic acid in gut by RT-PCR was consistent and more persistent viral shedding was detected in faeces than in nasal exudates. We describe a complete update of IBV distribution in tissues by the use of molecular techniques and we also provide and in-depth pathological characterization of the new Italy 02 IBV serotype. Furthermore, new data about IBV pathogenesis essential in field control is afforded.
authors.affiliation: Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain. roser.dolz@cresa.uab.cat
authors.forename: Roser
authors.initials: R
authors.lastname: Dolz
authors.forename: Júlia
authors.initials: J
authors.lastname: Vergara-Alert
authors.forename: Mónica
authors.initials: M
authors.lastname: Pérez
authors.forename: Joan
authors.initials: J
authors.lastname: Pujols
authors.forename: Natàlia
authors.initials: N
authors.lastname: Majó
mesh_terms: D000818:Animals; D002645:Chickens / Q000821:virology*; D002988:Cloaca / Q000473:pathology / Q000821:virology; D018352:Coronavirus Infections / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D005060:Europe; D005260:Female; D017403:In Situ Hybridization / Q000662:veterinary; D001351:Infectious bronchitis virus / Q000235:genetics* / Q000472:pathogenicity; D007668:Kidney / Q000473:pathology / Q000821:virology; D009296:Nasal Cavity / Q000473:pathology / Q000821:virology; D011201:Poultry Diseases / Q000175:diagnosis / Q000473:pathology / Q000821:virology*; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D014132:Trachea / Q000473:pathology / Q000821:virology; D017201:Virus Shedding
chemical_list: D012367:RNA, Viral