The authors reported some occurrences of the coronavirus infection in pheasants and red-partridges reared in the Emilia-Romagna Region of Northern Italy. During May 1996 a pathological condition was seen in a pheasant farm of approximately 8,000 breeders with up to 10% mortality observed in younger birds. Kidney lesions were constantly seen and urolithiasis and visceral gout were sometimes observed. Ultrastructural exams have been made on the kidney lesions. Coronavirus particles were isolated after three chicken embryo passages of cecal tonsil and kidney suspensions. In order to characterise the virus, serum neutralisation tests in chick embryo tracheal organ cultures were carried out using 12 infectious bronchitis virus (IBV) strains. The isolate designed Pheasant/Italy(Ra)/1754-13/1996 only showed low serum neutralisation titres with the French IBV type CR-84221. A second isolate (Pheasant/Italy(Ra)/5700/2000) was obtained from a game bird farm where about 1,000 pheasant breeders were reared. In July 2000, mortality, kidney lesions and visceral gout were seen in young birds (2-7-week-old). Coronavirus particles, isolated after two chicken embryo blind passages of kidney suspension, were detected by electron microscopy. Finally, a third strain (Red-legged Partridge/Italy(Ra)/191390/2004) was isolated in August 2004 from kidney lesions of one out 13 scanty red-legged partridges chosen from 10,000 birds recently imported from France (Region of Western Loire) for hunting purposes. Coronavirus infection was diagnosed by RT-PCR carried out on allantoic fluid (third passage) of chicken embrionated eggs. Genomic characterization of both S1 and M proteins of these strains and their phylogenetic correlation with other avian coronavirus is presented. The first pheasant outbreak described above, induced us to carry out a serological survey in the Emilia-Romagna Region in order to establish the occurrence and diffusion of coronavirus infection in farm-bred pheasants. Seven hundred and four sera were obtained during 1998 from 16 game farms. Moreover, 275 sera were collected from 1995 to 2002 from free-living pheasants, belonging to a natural population: these were classified as “wild” and “restocked” (a few reared birds released in the study area). A commercial blocking ELISA (Svanovir) test was employed for the detection of cross reactive antibodies anti-fowl coronavirus (Infectious Bronchitis virus) in sera. Seropositive animals were detected in 5 out of 16 game farms examined, while only two free-living pheasants (a restocked bird and an unclassified one) were seropositive. Serological data confirm that the infection was present in Italian-reared pheasants, but the free-living sampled population appeared to be free from the infection. The authors emphasise the risk of spreading the infection to wild bird populations by game restocking activities.
Coronavirus isolation and serological evidences ingame birds reared in Italy
De Marco M. A.;CATELLI, ELENA;DELOGU, MAURO;CECCHINATO, MATTIA;
2005
Abstract
The authors reported some occurrences of the coronavirus infection in pheasants and red-partridges reared in the Emilia-Romagna Region of Northern Italy. During May 1996 a pathological condition was seen in a pheasant farm of approximately 8,000 breeders with up to 10% mortality observed in younger birds. Kidney lesions were constantly seen and urolithiasis and visceral gout were sometimes observed. Ultrastructural exams have been made on the kidney lesions. Coronavirus particles were isolated after three chicken embryo passages of cecal tonsil and kidney suspensions. In order to characterise the virus, serum neutralisation tests in chick embryo tracheal organ cultures were carried out using 12 infectious bronchitis virus (IBV) strains. The isolate designed Pheasant/Italy(Ra)/1754-13/1996 only showed low serum neutralisation titres with the French IBV type CR-84221. A second isolate (Pheasant/Italy(Ra)/5700/2000) was obtained from a game bird farm where about 1,000 pheasant breeders were reared. In July 2000, mortality, kidney lesions and visceral gout were seen in young birds (2-7-week-old). Coronavirus particles, isolated after two chicken embryo blind passages of kidney suspension, were detected by electron microscopy. Finally, a third strain (Red-legged Partridge/Italy(Ra)/191390/2004) was isolated in August 2004 from kidney lesions of one out 13 scanty red-legged partridges chosen from 10,000 birds recently imported from France (Region of Western Loire) for hunting purposes. Coronavirus infection was diagnosed by RT-PCR carried out on allantoic fluid (third passage) of chicken embrionated eggs. Genomic characterization of both S1 and M proteins of these strains and their phylogenetic correlation with other avian coronavirus is presented. The first pheasant outbreak described above, induced us to carry out a serological survey in the Emilia-Romagna Region in order to establish the occurrence and diffusion of coronavirus infection in farm-bred pheasants. Seven hundred and four sera were obtained during 1998 from 16 game farms. Moreover, 275 sera were collected from 1995 to 2002 from free-living pheasants, belonging to a natural population: these were classified as “wild” and “restocked” (a few reared birds released in the study area). A commercial blocking ELISA (Svanovir) test was employed for the detection of cross reactive antibodies anti-fowl coronavirus (Infectious Bronchitis virus) in sera. Seropositive animals were detected in 5 out of 16 game farms examined, while only two free-living pheasants (a restocked bird and an unclassified one) were seropositive. Serological data confirm that the infection was present in Italian-reared pheasants, but the free-living sampled population appeared to be free from the infection. The authors emphasise the risk of spreading the infection to wild bird populations by game restocking activities.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
