Pathogenicity of Low and Highly VirulentChlamydia psittaciIsolates for Specific-Pathogen-Free Chickens

A parrot‐typeChlamydia psittacistrain is in association with egg production drop in laying ducks

“…The bacteria can localize in cells of conjunctiva, the gastrointestinal tract and most organs in birds (Stewardson & Grayson, ). An interesting study showed that C. psittaci can replicate in the upper (conchae and trachea) and lower (lung and abdominal and thoracic air sacs) respiratory tract, as well as in the spleen, kidney and jejunum in the SPF chickens (Yin et al, ). Although C. psittaci infection in ducks has been reported previously (Arzey et al, ; Chalmers et al, ; Hinton et al, ; Laroucau et al, ; Vorimore et al, ), only few studies previously focused on the tissue distribution of C. psittaci in infected ducks.…”

Chlamydia Psittaci Strains from Broiler Chickens Induce Histopathological Lesions and Mortality in SPF Chickens

“…Genotype B and especially genotype D strains cause severe respiratory disease in SPF chickens (24,25). Until recently, it was commonly assumed that C. psittaci is less pathogenic for chickens than for turkeys and ducks.…”

“…Thus, a systematic C. psittaci examination in case of respiratory disease in chickens is justified, in particular, when diseased birds display gross pathological and histopathological lesions as described here. Replication of C. psittaci is the highest in the air sacs and to a lesser extent in lung tissue (24,25). The liver and spleen, which are frequently examined for differential diagnosis, are thus less desirable organs to detect C. psittaci.…”

Full Issue

“…There are numerous reports of natural outbreaks (11,34,39,43,48,53,59,64) of chlamydiosis in turkeys in the United States, Canada, Europe, and Israel. There are also reports of experimental reproduction of chlamydiosis in turkeys (1,7,10,20,40,42,45,48,55,58,61) and turkey isolates in chickens (5,6,54,65,66). There have also been many reports of chlamydiosis in employees of turkey processing plants (2,16,24,25,39) and one outbreak in a diagnostic laboratory where employees were exposed to sick and infected turkeys (18).…”

“…Most of the previous studies on immunization focused on active vaccination, which has been comprehensively reviewed in recent articles (66,88,114,156). Identification of immunogenic and potentially protective antigens in C. jejuni has resulted in recent vaccine development being focused on subunit vaccines using various delivery systems such as oral live Salmonella-vectored vaccine (62,63,149,150,156,239), Eimeria parasite vector-based live vaccine (53), and nanoparticle-encapsulated vaccine administered via oral route (13) or intranasal route (123).…”