Molecular identification of aviadenoviruses in broiler chickens suspected to inclusion body hepatitis in Golestan province, Iran.

BACKGROUND: Fowl adenoviruses (FAdVs) are distributed widely throughout the world, and domestic avian species of all ages are susceptible. Fowl aviadenoviruses (FAdVs) can be separated into 5 different species (A-E) with various genotypes and 12 serotypes. Some geno- or serotypes induce hepatitis-hydropericardium syndrome (HPS), inclusion body hepatitis (IBH), and adenoviral gizzard erosion (AGE). AIMS: Detect FAdVs serologically and molecularly and sequencing of FAdVs in broiler flocks in Golestan province. METHODS: From December 2017 to June 2018 liver tissues and blood samples were collected from 31 broiler flocks suspected of IBH. Polymerase chain reaction (PCR) was applied on liver samples and the positive samples were sequenced and antibody against FAdVs was measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Out of 31 flocks, the titers of 29 flocks (93.5%) were high in ELISA test for FAdVs and 22 flocks (70.96%) were positive in PCR test. Sequence analysis indicated the isolates belonged to D and E genotype of adenovirus. CONCLUSION: Inclusion body hepatitis caused by FAdVs, are spreading increasingly in broiler flocks of Golestan province and more attention and surveillance programs of breeder and broiler farms are needed to develop preventive measures. Moreover, vaccination of poultry farms in Iran should be considered by more complement studies.

Molecular identification of reovirus in broiler type flocks in Golestan province, Iran.

BACKGROUND: Avian reovirus (ARV) has a global distribution in nature and most clinical signs are found in broiler type chickens. AIMS: This study was conducted to detect and identify reovirus infections from vaccinated breeder chickens and their progenies. METHODS: A total of 20 tissue and blood samples were collected from vaccinated broiler breeders and their progenies with gastrointestinal or performance problems during peak production. Antibody titers were measured by indirect enzyme-linked immunosorbent assay (ELISA) tests. RNA extraction from tissue samples was performed and cDNA was prepared and directly used in the polymerase chain reaction (PCR). Nucleotide sequences were bilaterally determined using internal primers. The analysis of the nucleotide sequences and their related amino acids was performed by the specialized Molecular Evolutionary Genetics Analysis software (6th version). RESULTS: The virus variant was detected in two vaccinated broiler breeders and five broiler flocks. The vaccine strains in breeder flocks included S1133, SS412, 1733, 2408 belonging to genotype 1 from the reovirus phylogenetic tree. Sequence 7 from the isolated reovirus based on the σC revealed that they were different from the reovirus vaccine, and that 6 isolates belonged to genotype 1 of the phylogenetic tree while 1 isolate belonged to branch 4 of the phylogenetic tree. CONCLUSION: The study showed that the new reovirus strain isolated from vaccinated birds differs from common strains used in the vaccines. It is therefore essential to prevent the effects of the field reovirus on the performance of industrial poultry, by updating and inventing new commercial vaccines, live and killed, against the reovirus.

Experimental Infection of Turkeys with A Virulent Newcastle Disease Virus Isolated from Broiler Chickens.

Newcastle disease (ND) is a highly contagious infection of many avian species, mainly chickens and turkeys, with a devastating impact on worldwide poultry production. The ND accounts for heavy losses in Iranian poultry flocks. There are some reports regarding the epidemiology of this infection in Iran. This study was performed to investigate the infection of turkeys with a Newcastle disease virus (NDV) isolated from a broiler chicken flock in southwestern Iran during 2013. For the purpose of the study, 70 day-old Wishard bronze poults were allocated into two groups of control (n=25) and infected (n=45). At 32 days of age, each bird in the infected group was inoculated with 0.1 mL (50 μL per eye) of NDV-infected allantoic fluid through an ocular route and received 105 EID50 of viral inoculum. On the other hand, the birds in the control group were inoculated with phosphate buffered saline by the same route. Swab samples were taken from both groups at different time points, namely from 1 to 21 days postinoculation, and verified for NDV infection by using reverse transcription-polymerase chain reaction (RT-PCR). Both groups were also examined serologically by haemagglutination inhibition test. Clinically, the infected turkeys exhibited anorexia, severe depression, sitting on the hock joint, white to greenish (sometimes bloody) diarrhea, neurological disorders, and mild respiratory problems. Out of 45 inoculated birds, 9 (20%) cases died. Based on RT-PCR, virus shedding was observed in the challenged birds 3-8 days postinoculation. The NDV was detected more in tracheal swabs (50%) than in cloacal swabs (12.5%). The infected birds showed a high seroconversion. Therefore, the NDV circulating in Iranian chicken flocks has the potential to cause a serious illness in commercial turkeys. The vaccination of turkeys, as well as biosecurity, should be considered carefully to prevent the ND outbreaks in the future.

Detection of Newcastle Disease, H9N2 Avian Influenza, and Infectious Bronchitis Viruses in Respiratory Diseases in Backyard Chickens in Ahvaz, Iran, in 2014-2015.

Newcastle disease virus (NDV), avian influenza virus (AIV), and infectious bronchitis virus (IBV) are the most prevalent viral pathogens in the Iranian poultry industry. This study aimed to reveal the presence of these viruses in the backyard chickens in Ahvaz, located in the Southwest of Iran. A total of 100 chickens with respiratory signs and mortality were examined by taking the blood samples as well as tracheal and cloacal swabs. Most of the chickens had not received any vaccine. The blood samples were assessed for the antibodies against NDV and AIV by haemagglutination inhibition test, and against IBV by enzyme-linked immunosorbent assay. The swab samples were utilized for molecular detection using reverse transcription polymerase chain reaction (RT-PCR). Based on the results of the serologic test, 77%, 45%, and 38.4% of the birds were positive for NDV, AIV, and IBV, respectively. In the RT-PCR, 95% of the birds were positive for one of the three viruses. The detection rates of NDV, AIV, and IBV were 60%, 34%, and 55%, respectively. The coinfections of AIV/NDV, AIV/IBV, NDV/IBV, and AIV/NDV/ IBV were observed in 13%, 4%, 23%, and 7% of the sampled chickens, respectively. The results demonstrated that the Iranian backyard chickens were infected with NDV, AIV, and IBV. This could pose a threat to the commercial poultry; therefore, preventive measures need to be implemented in this regard.

An Investigation into Enterobacteriaceae Responsible for Early Mortality in Japanese Quail Chicks and Their Antibiotic Susceptibility Patterns.

Quail is an alternative source of protein for humans. These birds can be affected by common bacterial infections. Bacterial contamination of egg is the most common cause of mortality in Japanese quail chicks. In order to study the role of some members of Enterobacteriaceae responsible for early mortality in Japanese quail chicks, 100 dead or moribund quail chicks were obtained from 10 different farms in Ahvaz, Iran. Samples were taken from the liver and yolk sac of the birds and bacterial isolation from samples was conducted by streaking them on MacConkey, Brilliant Green, Salmonella-Shigella and Xylose Lysine Deoxycholate agar plates. The plates were incubated at 37 °C for 24-48 hours, and by standard biochemical tests bacterial isolates were identified. Final confirmation of Salmonella serotypes was performed by Razi Institute. All the isolates were examined for susceptibility to 12 different antibiotics (Padtan-Teb Co., Tehran, Iran) by the disk diffusion (Kirby Bauer) method. The results showed that 78% of the quail chicks were infected. The isolated bacteria were Escherichia coli (44%), Klebsiella pneumonia (8%), Salmonella serovar ruzizi (5%), Salmonella serovar typhimurium (3%), Enterobacter cloacae (4%), Enterobacter aerogenes (4%), Proteus vulgaris (5%) and Proteus mirabilis (5%). One hundred percent susceptibility was observed to gentamycin, soltrim, tetracycline, fosfomycin, florfenicol, cephalexin and ceftriaxone. E. coli isolates were susceptible to soltrim and ceftriaxone, Salmonella isolates were susceptible to fosfomycin, Enterobacter isolates were susceptible to ceftriaxone and Proteus and Klebsiella isolates showed susceptibility to ceftriaxone. It is concluded that the members of Enterobacteriaceae family, specifically the genera Escherichia and Salmonella, are the major causes of early mortality in newly-hatched Japanese quail chicks.

Effect of dietary garlic on immune response of broiler chicks to live Newcastle Disease vaccine.

This study was designed to determine the effect of garlic powder on humoral immune response of broilers against NDV (Newcastle Disease Virus) vaccine. Two hundred and forty, two-day-old, Ross chicks were randomly assigned into 4 groups of 60 birds each. Chicks in groups 1 and 2 were given control mash diet during the experiment (6 week), but those in groups 3 and 4 were fed on control diet supplemented with 1 and 3% garlic powder, respectively. All groups except number 1 were vaccinated by eye-drop with B1 strain (Pestikal, Croatia) at 9 and 18 days of age. Ten blood samples were taken from each group on days 0, 14, 24 and 34 after first vaccination. The serum antibody level against NDV was measured by both HI and ELISA tests. The EDTA-mixed blood samples were examined for total and differential leukocyte count. The results showed that antibody titers in vaccinated chicks were significantly more than in non-vaccinated chicks (p < 0.05), but not influenced by the diet (p > 0.05). A significant increase of total leukocyte and percentage of lymphocytes was observed in vaccinated chicks 14 days after vaccination, but there were no difference (p > 0.05) among vaccinated groups. It is concluded that inclusion of garlic powder to the diet of broilers don't have any beneficial effect on humoral immune response to live NDV vaccine.