Evaluation of viral load and expression level of apoptotic genes in selected tissues of two hybrids of commercial broiler chickens challenged with infectious bronchitis virus: a comparative study.

Background: Infectious bronchitis virus (IBV) causes severe economic losses worldwide. IBV has a broad tissue distribution with different viral loads in different tissues. Additionally, IBV can induce apoptosis in infected cells. Aims: The present study aimed to evaluate the role of the genetic background of chickens in viral load and the expression level of apoptotic genes in different tissues of two hybrids of commercial broiler chickens (Ross 308 and Cobb 500) challenged with IBV. Methods: Chickens at 21 days of age were nasally challenged with 200 µL of allantoic fluid containing 104 EID50/ml of Iranian variant-2-like IBV (IS/1494). The expression level of apoptotic genes (Fas, FasL, Bax, and Bcl-2) in the tracheal and renal tissues and the amount of viral load in the tracheal, renal, and cloacal swab samples were investigated two, five, and seven days after IBV infection by RT-qPCR assay. Results: The amount of viral load and apoptotic the expression level of apoptotic genes in the tracheal (two and five days after infection) and renal samples (seven days after infection) were significantly higher in the Ross challenged group than in the Cobb challenged group.Furthermore, no difference was observed in the cloaca viral load on sampling days. Conclusion: To our knowledge, this is the first report that evaluated the role of the chickens' genetic background in the amount of viral load and the expression level of apoptotic genes against IBV. Further studies are needed to investigate the pathogenic characteristics of IBV in Ross 308 and Cobb 500 chickens.

Assessing the economic burden of multi-causal respiratory diseases in broiler farms in Iran.

The aim of this study was to find the direct economic losses due to the three viral causes of the avian respiratory syndrome, including Newcastle disease (ND), H9N2 influenza, and infectious bronchitis (IB) in stamped-out broiler farms during 2016-2017 across the country. This study was carried out on the information on cross-sectional monitoring in the years 2016-2017. The statistical society of the study was all the active broiler farms of the country stamped out due to respiratory syndrome. This study used compensation insurance data, and other sources. One-way ANOVA or Kruskal-Wallis tests were used to analyze normally and non-normally distributed data. In total, during the study period, 132 broiler farms and 1,723,131 fowls were stamped out. According to the results of the present investigation, the sum of costs and losses due to respiratory complex was 9.47 $US Million, 2016-2017 (5.72 from $US Million chicken meat losses and 3.75 $US Million was the total cost). ND was the main cause of economic losses and costs with 3.86 $US equal to 40.8% of the total. Cost of feeding was the highest followed by veterinary services and medicines, vaccination, and 1-day-old chicks costs with 2.27, 1.11, 0.33, and 0.036 $US Million, 2016-2017. In conclusion, we need to improve the preventive measures against respiratory viruses, especially NDV. Additionally, as the cost of feeding was the largest, it is important to shorten the time interval between disease occurrence and stamping out to reduce the cost.

Report of a new meq gene size: The first study on genetic characterisation of Marek's disease viruses circulating in Iranian commercial layer and backyard chicken.

1. In recent months, several outbreaks with clinical signs of MDV-1 were reported in Iranian parent and laying hen farms, in addition to backyard chickens. Several meq gene sequences from these outbreaks were amplified and molecularly characterised.2. The meq protein sequences revealed three different sizes, namely the standard 339 aa, a shorter form of 338 aa lacking a proline residue at position 191, and a very short (vs) size of 265 aa. Based on sequence and size, the 265 aa meq has never been reported from international research groups before. The protein has only one PPPP repeat motif suggesting it belongs to a highly virulent strain.3. The standard meq sequences showed 100% BLAST identity to the vv+ isolate Polen5. However, the 338 aa form clustered to the clade usually reported from North America.4. This is the first report on genetic analysis of MDV-1 from Iran, but further study is required to obtain a better picture of the diversity and prevalence of different MDV-1 strains circulating in the country's farms, backyard poultry and other bird species.

Molecular characterization of circulating avian metapneumovirus, subgroup B, in broiler chickens, Iran, 2016-2018.

BACKGROUND: Avian metapneumovirus (aMPV) infection has significant economic impacts on the poultry industry all around the world. AIMS: The aim of this study is molecular investigations of different types of aMPV in broiler farms in different provinces of Iran from 2016 to 2018. METHODS: Tracheal and oropharyngeal swabs were collected from two hundred broiler chickens with respiratory signs in ten provinces of Iran, including Kurdistan, West Azerbaijan, Semnan, Esfahan, Sistan and Baluchistan, Qazvin, Khuzestan, Fars, Gilan, and Khorasan Razavi from February 2016 to December 2018. After RNA extraction, the presence of aMPV was confirmed using N gene special primers. Then, subtype-specific primers were utilized to differentiate the specific subtype. All positive samples were sequenced. RESULTS: As a general trend, the percentage of aMPV positive chickens increased gradually over time. All samples were clustered together and placed in the subtype B aMPV group. Although 2 samples from 2016 and 2 samples from 2018 were placed in a separate branch, most of the current study samples of 2016, 2017, and 2018 revealed six segregated sub-branches, and they were placed close to other isolates of 2011 and 2013 from Iran. CONCLUSION: The current field study indicated the presence of aMPV in a considerable number of areas in Iran. Thus, the role of this virus in broiler respiratory complex should not be neglected.

Molecular detection of fowl adenovirus 7 from slaughtered broiler chickens in Iran: the first report.

BACKGROUND: Fowl adenoviruses (FAdVs) are responsible for a variety of clinical symptoms, with an increasing significance in the poultry industry throughout the world. Typical diseases caused by FAdVs include inclusion body hepatitis (IBH), hepatitis-hydropericardium syndrome (HHS), gizzard erosion (GE), respiratory disease, and hemorrhage in muscles and organs. AIMS: During 2020, broiler chickens from the north of Iran showed ecchymotic and petechial hemorrhages in thigh and breast muscles at the slaughterhouse. Hemorrhages were observed in 10% to 60% (with an average of 20-30%) of chicks per flock. To find out the etiology of these lesions, the present study was conducted. METHODS: Different environmental factors were investigated, and FAdV, infectious bursal disease virus (IBDV), and chicken infectious anemia virus (CIAV) were detected using molecular assays. RESULTS: Among the viruses tested, FAdV was detected by polymerase chain reaction (PCR), and sequence analysis clustered the virus into species E, serotype 7. CONCLUSION: This is the first report on FAdV-7 existence among poultry in Iran. Effective screening of the chicks at slaughtering age should be performed from the whole country.

Outbreak Investigation of Officially Reported and Highly Pathogenic Avian Influenza (H5N8 Subtype) in Iran During 2016.

On 14 November 2016, an outbreak of highly pathogenic avian influenza (HPA) was reported from a commercial layer farm located in Malard, Tehran Province, Iran. This study aimed to investigate the HPAI H5N8 outbreaks in Iran. The questionnaire was prepared and completed through interviews with farm owners or field observations at the time of disease onset from November 2016 to February 2017. The HPAI H5N8 infection was confirmed in 30 different locations including 10 villages (33.3%), nine-layer farms (33%), two broiler breeder farms (6.67%), one layer breeder farm (3.3%), one turkey farm (3.3%), one partridge farm (3.3%), five national parks (16.7%), and one wetland (3.3%) in 12 provinces of Iran. The cumulative incidence rates of disease in villages, layer farms, broiler breeder farms, layer breeder farms, partridge farms, and turkey farms were 0.02%, 0.87%, 0.55%, 6.25%, 7.14%, and 0.69%, respectively. The findings reflect that among the investigated variables at infected locations, new birds entering the home in villages, live bird markets, inappropriate biosecurity conditions, transporting manure during the breeding period, close proximity of a common road to infected farms, and poultry movement inside (pullet) and outside were the most frequently observed possible risk factors for these outbreaks. In conclusion, attention should be focused on the study of the dynamics and movements of domestic poultry, investigation and modification of the structure of industrial poultry farms, training for all related people, enhancement of passive surveillance, an increase in biosecurity, raising the awareness of the authorities on the importance of the infection, and provision of the required credits and facilities.

Hemagglutinin-neuraminidase Sequence and Phylogenetic Analysis of Two Newcastle Disease Virus Isolated from Chickens in Iran.

Newcastle disease is a highly contagious viral infection affecting many species of birds that can spread fast between poultry houses and cause a heavy economic burden on the poultry industry all around the world. Fusion and hemagglutinin-neuraminidase (HN) protein are important in the pathogenesis of the Newcastle disease virus (NDV). The HN protein is a critical viral protein with multiple functions and plays a key role in the formation of the virulence of NDV. Head of HN protein is responsible for receptor binding, neuraminidase activity. This study aimed to investigate the sequence homology of hemagglutinin-neuraminidase of two NDV isolates sampled from infected farms in Iran. The samples were collected from flocks that had been vaccinated by both types of live and killed vaccines for NDV. After isolation of NDV, the viruses were subjected to the polymerase chain reaction (PCR) amplification using two pairs of specific primers designed for the HN gene to amplify the complete HN gene (1730bp). Afterward, the PCR products were sequenced and analyzed by phylogenetic tree construction software. Based on the analysis, substantial sequence homology among Iranian isolates is within the range of 97.1-100%. Moreover, the sequence homology searching revealed a level of similarity between HN sequences of Iranian isolates and the HN sequences from other countries, particularly Asian ones. For instance, a high homology ratio (95.34%) was found between Iranian isolates and the sequences registered on online molecular databases from China. Based on phylogenetic analysis, the NDV isolates belong to the VIId genotype. Finally, it can be concluded that monitoring the circulation of NDVs among poultry and other birds can help to obtain an insight into the evolution of NDVs and control of panzootic viruses in the future.

Detection and Phylogenetic Study of Peste des Petits Ruminants in Iran, 2019: Updated Data.

Peste des Petits Ruminants (PPR) is caused by a morbillivirus from the Paramyxoviridae family and the infected animals, especially goats, that show clinical signs of necrotic stomatitis, enteritis, and pneumonia. The PPR virus has four lineages closely related to the geographical regions. Sufficient awareness of the lineage of the virus helps monitor the disease in different regions of a country. Phylogenetic studies have led to implementing strategies against new lineages that may enter a given country from the neighboring countries. The present research aimed to study the PPR virus (PPRV) detected phylogenetically by PCR in a small ruminant flock with PPR clinical signs. The goats in a flock in Alborz province showed clinical signs of PPR, and 10% died. Oral swabs and blood samples were taken from two affected goat flocks. The RT-PCR was conducted to detect PPRV RNA, and the sequence of the obtained RNA was analyzed phylogenetically. Moreover, all the samples were positive for the presence of PPRV and belonged to lineage IV. The isolates had high homology with each other and with the isolates from different countries. To inhibit the entrance of new isolates to Iran and reduce the incidence of outbreaks in Iran, it is essential to control the animals’ movement across the borders and increase the vaccination coverage throughout the country. To eradicate PPR, an extensive vaccination program should cover small ruminant populations throughout the country.

laying Farm: Up to Date Data on a Fowlpox Outbreak in Phylogenetic Analysis in Iran, 2018.

Fowlpox is an economically significant viral disease in poultry, characterized by two forms of clinical signs, including cutaneous and diphtheritic lesions. This infection can have several adverse effects on flock performance, such as a reduction in egg production and growth and an increase in mortality. In winter 2018, an infection suspected to fowlpox was reported from a Hy-line W-36 laying farm in Isfahan province, Iran. The birds were 38 weeks of age and showed obvious diphtheritic signs in mucous membranes with increased mortality and reduced egg production. In total, 20 samples were collected from diphtheritic lesions (Trachea and Esophagus) of infected birds. The Polymerase Chain Reaction method was used to amplify a 578 bp fragment of the poxvirus 4b core protein gene. Phylogenetic relationships of avian poxviruses are usually analyzed using the 4b core protein-coding gene sequences with molecular weights of 75.2 kDa. The major elements had the fowlpox genome, and sequencing was performed for one isolate as representative. The nucleotide sequence result showed that this isolate (FP\UT-POX-2018) had a similarity rate of 99.53% with the previous Iranian fowlpox isolate (FP\GHPCRLAB.3) sequenced in the GenBank.Moreover, there was a 100% similarity among the current isolate nucleotide sequence, FP/NobilisVarioleW, and FP/FPV-VR250. The derived phylogenetic tree showed that these isolates were clustered in A1 subclades. Therefore, Iranian isolates of fowlpox virus have remained in the same subclade of phylogenetic classification (subclade A1), and they show high genomic similarity with previous isolates of Iran. Veterinarians and farmers must not underestimate fowlpox. However, they should consider the importance of vaccination against this disease like any other disease care.

Diagnosis of poult enteritis complex (PEC) and molecular detection of avian coronaviruses in some commercial turkey flocks in Iran.

BACKGROUND: Enteritis syndromes, also known as poult enteritis complex (PEC) with diverse etiologies, can affect turkey production. An avian coronavirus (AvCoV), turkey coronavirus (TCoV), is one of the most important viral causes of PEC in turkeys. AIMS: In the present study, the occurrence of PEC and the presence of AvCoV in some commercial turkey flocks were investigated. METHODS: PEC was diagnosed based on the history, clinical, and necropsy findings. A reverse transcriptase-polymerase chain reaction (RT-PCR) targeting the AvCoV nucleoprotein (N) gene was applied to detect the virus in the tissue samples. Cloacal swabs were collected from 11 flocks without a known history of PEC. RESULTS: PEC was diagnosed in six (16.2%) out of 37 investigated turkey flocks. The daily mortality rate in affected flocks ranged from 0.2 to 1.2%. Samples from 8 flocks out of 18 (44.4%) were positive for AvCoV. Four PEC affected flocks were positive for AvCoV. Seven positive samples were sequenced and phylogenetic analysis revealed the close relationship with previously characterized avian infectious bronchitis viruses (IBV). CONCLUSION: The results suggested that PEC should be considered as a significant syndrome in the Iranian turkey industry. According to this preliminary study, it was shown that avian coronavirus infection is prevalent in commercial turkey farms of Iran. However, no causative association could be concluded between PEC occurrence and AvCoV infection in turkey flocks.

Molecular characterization and the first full sequencing genome of chicken infectious anemia virus (CIAV) in Iran.

BACKGROUND: The chicken infectious anemia virus (CIAV) is an important pathogen that causes severe immunosuppression in young chickens. AIMS: The study aims to characterize the genotype and full-length sequencing of CIAV strains in Iran. METHODS: First, the collected thymus samples were investigated by conventional PCR for CIAV detection. Second, one of the CIAV positive samples (UT-Zahraee) was chosen for full genome sequencing. RESULTS: Throughout 2017, we detected 13 CIAVs isolated from 40 broiler flocks of different provinces of Iran. A comparison of the complete sequences of the genome and homologies of the nucleotides revealed that UT-Zahraee had a high similarity with American and Egyptian CIAV isolates. Moreover, VP1 sequence analysis showed that UT-Zahraee shared high homology with previously reported Iranian CIAV strains, Chinese, and Egyptian isolates. CONCLUSION: This study is the first report of full genome sequencing of CIAV strain from Iran. It will be beneficial to understand better the epidemiology and molecular characteristics of CIAV circulating in Iran.

Comparative trachea transcriptome analysis between avian infectious bronchitis virus and avian pathogenic E. coli individual infection and co-infection in SPF chickens.

Avian infectious bronchitis virus (IBV) and avian pathogenic Escherichia coli (APEC) are two important respiratory pathogens in the chicken. The co-infection can lead to chronic complications and considerable economic losses in the poultry industry worldwide. In the present study, we compared differential transcriptional profiles in the trachea tissue of three infected groups (IBV, APEC, and co-infection) with the control group to investigate transcriptome profile changes at the early stage of the infection. After the challenge of SPF chickens with IBV IS-1494 like (GI-23) and APEC, serotype O78: K80, or co-infection, the trachea tissue was used for RNA extraction, and changes in the transcriptome were investigated by Illumina RNA-seq technique. Up-regulated and down-regulated differentially expressed genes (DEGs) in the transcriptome of each group's trachea were identified. Gene ontology category, KEGG pathway, and gene interaction networks (STRING analysis) were analyzed to identify relationships among differentially expressed genes. In general, the numbers of up-regulated genes were higher than of down-regulated genes. In the co-infection group, a more severe immune response and macrophage infiltration occurred; an important cluster of pathway signaling in this group's up-regulated genes was an apoptotic cluster, cytokine-mediated signaling cluster, and the PAMPs recognizing cluster. This is the first study to provide a general overview of transcriptome changes in the trachea at the early stage of infection with these pathogens. Keywords: avian infectious bronchitis virus; avian pathogenic E. coli; transcriptome; RNA-Seq.

The emergence of Q1 genotype of avian infectious bronchitis virus in Iran, 2019: the first report.

BACKGROUND: Avian infectious bronchitis (IB) is an infectious viral disease of chickens. The effective protection of chickens against many different infectious bronchitis virus (IBV) variants is not achieved unless the circulating genotypes in the region are identified and the cross-protection of the potential of vaccines in use is assessed. AIMS: In a monitoring program of IBVs, a new genotype was identified in the north of Iran, 2019. This work was conducted to isolate and characterize this new IBV genotype. METHODS: Tracheal tissues were collected from chickens showing signs of respiratory involvement. Specimens were homogenized and inoculated to the allantoic fluid of embryonated specific pathogen-free (SPF) eggs. Infectious bronchitis virus was detected using real time-polymerase chain reaction (RT-PCR). The hypervariable region of the IBV S1 gene was amplified for sequencing. RESULTS: Positive samples were phylogenetically analyzed, and both positive isolates were clustered with Q1 IBV strains. CONCLUSION: This is the first report of the Q1 outbreak in Iran. More investigations are needed to find the role of Q1 IBV in the respiratory disease complex of chickens.

Avian Influenza (H9N2 Subtype) in Iranian Broiler Farms: A Cross-sectional Study.

The present study aimed to determine the seroprevalence of H9N2 influenza in broiler farms at the time of slaughter in Iran. A total of 747 birds were sampled from 74 Farms in 13 provinces within 2013-2016. The obtained sera were investigated using the hemagglutination inhibition (HI) test. Out of 74 sampled farms and 747 birds, 57 farms (77%) and 445 (59.57%) birds were reported to be seropositive. In 2013, 10 farms and 110 birds were sampled out of which three farms (29.6%) and 29 birds (30%) were seropositive. In 2014, 24 farms and 220 birds were sampled out of which 22 farms (91.6%) and 220 birds (86.6%) were positive in six provinces. In 2015, 30 farms and 278 birds were sampled out of which 5 farms (16%) and134 birds (48.2%) were positive in four provinces. Finally, in 2016, 7 farms (70%) out of 10 sampled farms and 62 birds (59%) out of 105 sampled birds were positive for H9N2 in eight provinces. The mean titer of units in 2013 was statistically lower, as compared to that in 2014 (p <0.01). In addition, the proportion of positive serum units in 2013 was statistically lower, as compared to that in 2014 (p <0.001). In general, the prevalence of H9N2 was high indicating the continuous circulation of the virus in Iran. Given the importance and impact of this virus on the poultry industry, people’s livelihood, and public health, more epidemiological studies are needed to evaluate the effectiveness of the adopted measures and methods in controlling the H9N2 virus.

Comparison of autogenous and commercial H9N2 avian influenza vaccines in a challenge with recent dominant virus.

BACKGROUND: Avian influenza (AI) caused by AI virus subtype H9N2 is a prevalent viral disease with enormous economic losses in poultry farms through significant respiratory and gastrointestinal manifestations. The degree of protection obtained from a vaccine strongly depends on the level of antigenic similarity between challenge and vaccine virus. AIMS: The study aimed at investigating the possible effects of continuous antigenic changes occurring in circulating Iranian viruses since 1998 on the commercial vaccines outcome by using vaccine seeds from earlier outbreaks for inhibiting viral replication in target organs of broilers challenged with the recent isolate. METHODS: Ninety broilers at one day of age were randomly allocated into 5 groups and vaccinated with autogenous or commercial vaccines (A or B). Two remaining groups consisted of challenged without vaccination and intact birds. Quantitative real time-polymerase chain reaction (qRT-PCR) was performed on the trachea and faecal samples of challenged chickens with recent H9N2 virus to determine viral load. Moreover, humoral antibodies titers were evaluated by hemagglutination inhibition (HI) assay. RESULTS: There was no significant difference in H9N2 viral load in the trachea among vaccinated groups on 5 days post challenge (DPC), but on 15 DPC, the autogenous vaccine significantly lowered viral load compared to commercial vaccines (P≤0.05). No significant differences in faecal swab's viral load was observed between autogenous and commercial vaccine A, and both of them significantly inhibited viral load compared to unvaccinated group (P≤0.05). In addition, the autogenous vaccine elicited the highest HI titer. CONCLUSION: Inactivated vaccines that use isolates from previous outbreaks are no longer able to induce proper immunity against recent H9N2 viruses. It seems the time to change vaccine strains to more recent isolates that have better antigenic similarity with current circulating H9N2 viruses in the region has come.

Molecular Monitoring of D1466 Genotype of Avian Infectious Bronchitis Virus in Iran: A Retrospective Study in 2013-2017.

Infectious bronchitis is one of the most common diseases in the poultry industry in many countries, especially in the regions with a dense poultry farming industry. Gammacoronavirus is the etiologic agent of this disease, with the chickens and poultries as the natural reservoirs of the virus. Various strains of infectious bronchitis virus have been reported in poultry around the world. In terms of pathogenicity, this virus can induce a spectrum of diseases ranging from the moderate respiratory tract to kidney and reproductive diseases. The serotypes of this virus do not cause cross-immunity against each other. This issue makes it difficult to control the disease. Based on the analysis of the highly variable region of the glycoprotein S1 gene, the isolated strains in Iran were classified into seven different phylogenetic groups, including Massachusetts, QX, IS-720, IS-1494, 793/B, IR-1, and IR-2. The D1466 genotype has not been reported in the country; however, the killed vaccine is used in broiler breeder farms. In this study, tissue specimens were collected from 700 farms (i.e., broiler, egg-laying, and broiler breeder farms) suspected of infectious bronchitis within 2013-2017. The samples were examined using real-time reverse transcription-polymerase chain reaction. The D1466 genotype was not detected in any of the studied specimens. Due to the lack of immunity of the D1466 serotype against the dominant types in the country, one has to be careful in choosing the right vaccine. It is necessary to perform continuous monitoring of the circulation status of the various serotypes of viruses in the country to identify the dominant and possible new serotypes for the utilization of the appropriate vaccine.

A Study on Isolation and Molecular Identification of Bordetella avium from Iranian Commercial and Backyard Broiler Turkeys within 2016-2018.

Bordetellosis or turkey coryza, caused by Bordetella avium, has been an issue for turkey industry since its first description in 1967 when it was reported for the first time. Bordetella avium causes a highly contagious upper respiratory disease in turkeys. Therefore, this study aimed to isolate and characterize this species from commercial and backyard turkeys in Tehran, Isfahan, and Northern provinces of Iran. For the purpose of the study, 625 tracheal swabs were taken from 425 commercial poults and 200 backyard poults aged 2-6 weeks from September 2016 to September 2018. The swabs were immediately plated on MacConkey and blood agar plates and then pooled (5 swabs/pool) in tubes, containing 2 mL distilled water, to perform direct polymerase chain reaction (PCR) for the identification of B. avium. A total of 17 swab pools were found to be positive for B. avium. A subset of seven positive samples were sequenced for the flanking region of piuA gene. The analysis of the sequences indicated that the sequences were 98%, 96%, and 98% similar to B. avium 197N (AM167904.1), 4142 (AY925058.1), and 4156 (AY925068.1) sequences, respectively. To the best of our knowledge, the current study is the first attempt toward the molecular detection and characterization of B. avium in Iran. It is highly recommended to perform further studies to isolate, characterize, and differentiate the regional isolates in order to help the developing turkey industry of Iran meet the increasing demands for protein in the diet of the citizenry.

Genotyping of avian infectious bronchitis virus in Afghanistan (2016-2017): the first report.

BACKGROUND: Avian infectious bronchitis (IB) is a highly contagious viral disease which affects the poultry industry. The virus exists in a wide variety of genotypes, and phylogenetic analysis has been used to classify infectious bronchitis virus (IBV) strains. AIMS: The object of the study is a molecular characterization of circulating IBV in Afghanistan as a first study. METHODS: The tracheal tissue specimens from 100 different commercial broiler flocks with respiratory distress in Afghanistan were collected during 2016-2017. After real-time reverse transcriptase-polymerase chain reaction (RRT-PCR), IBV-positive samples were further characterized. A 390 bp hypervariable spike glycoprotein gene segment was amplified using Nested PCR, sequenced, and analyzed. RESULTS: The results of real-time RT-PCR showed that 45/100 of the mentioned flocks were IBV positive. Phylogenetic analysis of all positive samples revealed that IBV strains were clustered into two distinct genotypes: LX4 (GI-19) (9/45) and IS-1494 like (GI-23) (34/45). Also, 2 of the 45 samples remained uncharacterized. CONCLUSION: It is the first study focusing on the molecular epidemiology of IBV in Afghanistan, extending our understanding of IB in the region. These results showed the high rate of IB infection in Afghanistan broiler farms and confirm the continuing monitoring of IBVs to modify the vaccination program.

Virus neutralization study using H120, H52, 793/B antisera against Iranian infectious bronchitis virus genotypes.

Infectious bronchitis virus (IBV), a major pathogen of the domestic fowl, exhibits extensive antigenic variation. IBV is a member of the Coronaviridae family and the genus Gammacoronavirus. A new infectious bronchitis virus serotype can emerge from only very few amino acid changes within the major peplomer glycoprotein, namely in its S1 part forming the virion spike. Principally, the serotypes are identified by virus neutralization (VN) tests. This study is aimed to investigate the neutralizing efficiency of H52, H120, and 4/91 antiserum against IBV genotypes (IS-1494, IS-720, 793/B, IR-1) recently circulating in Iran. For the first time, we have used cross-neutralization tests for the serological classification of these isolates. In this study, all antisera failed to neutralize all IBV strains. According to the results of our research, cross-protection studies are necessary for the design of a proper vaccination program for IBV circulating genotypes in Iran. The data are useful for the development of new vaccine strategies. Keywords: avian infectious bronchitis; Iran; virus neutralization.

Zataria multiflora essential oil reduces replication rate of avian influenza virus (H9N2 subtype) in challenged broiler chicks.

1. The effect of Zataria multiflora essential oil on replication rate of the H9N2 virus in target organs was determined by real-time PCR. One-day-old broiler chicks were randomly divided into six groups and were challenged with H9N2 influenza. Two groups received either 20 or 40 µl/kg body weight/day Zataria multiflora essential oils (ZM) seven days before the challenge while two other groups received the essential oil at the same dosage but after H9N2 challenge. One group received 4 mg/kg body weight/day of the anti-viral compound amantadine after challenge and the last group received no treatment and served as the control. 2. Groups that received the ZM, before or after H9N2 challenge, and the amantadine treated group showed reduced viral replication in the respiratory and gastrointestinal tracts compared to the control. Supplementation with ZM improved weight gain and FCR in broilers in comparison with the control. 3. The results showed that ZM had a positive effect on reducing viral replication in both the intestine and trachea of H9N2 influenza infected broiler chickens, that led to milder clinical symptoms and better performance.