Molecular detection and characterization of beak and feather disease virus in psittacine birds in Tehran, Iran

Beak and feather disease virus [BFDV], a member of genus circovirus, is a small, non-enveloped, single stranded DNA virus. Although BFDVs are among the most well studied circoviruses, there is little to no information about BFDVs in Iran. The aim of the present study was to detect and identify BFDV molecules from the birds referred to the avian clinic of The Faculty of Veterinary Medicine, Tehran University, Iran. A total of 55 DNA samples were extracted from birds from nine different species of the order psittaciformes. A robust conventional polymerase chain reaction [PCR] was applied to detect the rep gene of the virus. Ten out of 55 samples, from four different species, were tested positive for BFDVs in PCR [Melopsittacus undulates [4], Psittacula Krameri [3], Psittacus erithacus [2], Platycercus eximius [1]]. Molecular identification of the detected BFDVs was performed based on their rep gene sequences. The phylogenetic analysis revealed that the Iranian BFDVs from this study were clustered into four genetically distinct clades belonging to different genetic subtypes of BFDVs [L1, N1, T1, and I4]. Although the relation between the samples and their related subtypes in the tree are discussed, further studies are needed to elucidate the host specificity and incidence of the BFDVs from different genetic subtypes

[Efficacy of thermostable I-2 Newcastle disease vaccine compared to B1 commercial vaccine in broiler chicken]

Frequent vaccination failures have occurred in the broiler farms in Eurasian countries during Newcastle disease outbreaks. The disease is enzootic in many countries of the region, especially in southwest Asia. I-2 vaccine has been used successfully in village chickens in many Asian and African countries. Our preliminary study showed good efficacy of the vaccine in broiler chickens. Therefore the current experimental study was conducted to compare viral shedding period of heat resistance I-2 vaccine with B1 commercial vaccine following challenge with Herts'33. For this purpose three hundred commercial broilers were randomly allocated into four groups; 1] Thermostable I-2 vaccine, 2] Hitchner B1 vaccine, 3] Challenge group with no vaccine, and 4] Negative control group. Experimental chicks were vaccinated on days 19 and 26 by the eye drop route and then the birds were challenged via intra ocular route on day 40 with a suspension containing 10[6] EID[50]/ml challenge virus. Experimental chickens were monitored by collecting buccal and cloacal swabs at different times. Collected swabs were submitted to PCR test. The results showed that vaccination can protect the birds against mortality and also decrease virus shedding; also there was not a significant difference between vaccination with I-2 and B1 vaccines

Pathological lesions observed in chickens pre-infected with LP H7N1 A/CK/Italy/1279/99 avian influenza and challenged with homologous HP H7N1 A/ostrich/Italy/984/00

Most highly pathogenic avian influenza viruses [AIV] emerge after field passage of non-pathogenic AIVs in birds. The outbreak of low-pathogenic H7N1 avian influenza virus in Italy during 1999-2000 followed by outbreak of highly pathogenic H7N1 avian influenza virus is one example in this regard. This experiment has been designed to investigate the effect of pre-infection of birds with LPAI on subsequent challenge with HPAI virus from the same outbreak. Chickens were inoculated intranasally with LP H7N1 A/CK/ItaIy/1279/99 avian influenza virus at 3 weeks of age and two groups of 10 birds were challenged at 18 and 24 weeks of age with homologous HP H7N1 A/ostrich/Italy/984/00 virus from the same outbreak. The overall mortality of birds was 60%; pre-infected challenged birds died 4-17 days post challenge [PC], while naive birds died 2 days PC. Pre-infected birds showed peritonitis, salpingitis and oophoritis in necropsy and histopathology showed very severe necrosis of the spleen, pancreas, moderate to severe necrosis of the liver and inconsistent degeneration and inflammation of the lung. Necropsy of the control bird showed petechial haemorrhage on the heart, caecal tonsils and the tracheal mucosa

Pathological changes in turkeys experimentally infected with different doses of A/ostrich/Italy/984/2000 H7N1 avian influenza virus

Following experimental inoculation of 3-week-old turkeys with different titres [10[6], 10[4], 10[3], 10[2] and 10[1] egg infectious dose [EID50]] of A/ostrich/Italy/984/2000 H7NI highly pathogenic avian influenza virus [HPAIV], the selected tissues and organs were examined for pathological changes. Tissue samples from different organs that obtained from dead and sacrificed birds were fixed in 10% neutral buffer formaldehyde. Mortality of turkeys which inoculated with different doses of EID50 at different times post inoculation [PI] is as follows: 1] at 48 h PI [HPI]: one, two and four turkeys inoculated with 10[3], 10[4] and 10[6] EID50, respectively 2] at 72 HPI: two, two and one turkeys inoculated with 10[2], 10[3] and 10[6] EID50, respectively 3] at 96 HPI: one and two turkeys inoculated with 10[2] and 10[4] EID50, respectively and 4] at 120 HPI: just one turkey inoculated with 10[4] EID50. Birds inoculated with 10[1] EID50 did not show any mortality. Seven days PI [DPI] the remaining birds were sacrificed. Postmortem examination of birds that died 48 HPI showed very severe hyperaemia and haemorrhage of the lung, slight swelling of kidneys and splenomegaly. Moderate to slight hyperaemia of the lung was observed in the birds sacrificed on day 7. Histopathology showed very severe haemorrhage and vasculitis in the lung, multifocal areas of degeneration and necrosis in the pancreas of birds inoculated with 10[6] EID50. Hyperaemia, haemorrhage, degeneration and vasculitis were also observed in the lung of birds from the other groups; however the severity of lesions correlated positively with the viral dose. The spleen, caecal tonsils and thymus showed extensive necrosis and lymphoid depletion, even in birds inoculated with 10[2] and 10[1] EID50 that were sacrificed 7 DPI, and some repopulation of the spleen was observed 7 DPI. Other organs including the kidneys and adrenal gland showed moderate to slight hyperaemia and necrosis. In conclusion, the lung vascular damage, lymphoid tissue destruction and necrosis were notable even with low viral doses

Thermostability and efficacy of 1-2 vaccine against Newcastle disease [ND] in Iran: a pilot study

Thermostable vaccine against Newcastle disease [ND] is a potential alternative to chicken vaccination in villages, since cold chain is not needed in this process. The purpose of this study was to investigate thermostability and efficacy of 1-2 vaccine against ND. The vaccine tested for sterility, intracerebral pathogenicity index [ICPI] and 50% embryo infectious dose [EID50]. The wet vaccine stored at 20°C for 1,2 and 4 weeks named A, B and D, respectively. Each preparation [10 [7.5] EID50] was used to inoculate twenty, 4-week-old chicks via eye drop. All groups except the control were vaccinated twice in 2 weeks interval. Haemagglutination inhibition test used for evaluation of the antibody response. Two weeks after the first vaccination, a peak titer of about log.2 [6] and log.2 [4.6] was observed in A and B groups, but D group did not induce any antibody response in their sera. All the vaccinated groups responded to vaccination after second trial and produced mean titers of log.2 [6.2], log.2 [6] and log.2 [5.4] were observed, respectively

Histopathological and bacteriological studies on the cull laying hens' reproductive system

Disorders of laying hens' reproductive system such as: egg-peritonitis, salpingitis and oophoritis have been gaining increasing attention due to immense economic losses that are being inflicted by these conditions on the growing poultry industry. In order to determine the incidence of salpingitis, oophoritis and egg peritonitis in cull laying hens, 1041 cull laying hens from commercial laying farms in Fars province were necropsied. Among these 86 [8.26%] cases showed at least one lesion in their reproductive system, of which 37 [3.55%] carcasses exhibited gross lesions of both egg peritonitis and salpingitis, salpingitis 37 [3.55%], egg peritonitis 7 [0.67%] and oophoritis 5 [0,48%]. The overall condition was found to be 86 [8.26%]. Bacterial culture of 86 suspected cases of inflammatory reactions of the ovary, the oviduct and the peritoneal cavity yielded Esherichia coli in 62 [5.95%] of cases, Salmonella spp in 4 [0.38%] of cases, Proteus Vulgaris in 2 [0.19%] of cases and Klebsiella in 1 [0.09%] of cases and mixed bacterial infection in 9 [0.86%] cases. No bacteria was isolated from 8 [0.76%] of suspected cases. Lesions at gross and microscopic level and also bacteriological findings were recorded and compared with other workers results