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The present study reports the presence of N. caninum DNA by PCR in brain tissues of house sparrows. The results showed that 6 (2.8%) of brain samples were positive for N. caninum. This is the first report for detection of N. caninum in sparrows, in Khuzestan Province. The results suggest that the meat of infected sparrows can be the source for dogs' infection.

Newcastle disease virus (NDV) is a serious threat to the international poultry industry. Therefore, to determine the role of pet birds (Psittaciformes and Passeriformes) in its spread and epidemiology, the presence of this virus in these birds was investigated. In this study, fecal and cloaca swabs from 63 Psittaciformes and 37 Passeriformes, along with tissue samples of dead birds, including proventriculus, trachea, lungs, and intestine, were collected from breeding and sales markets as well as the birds referred to Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran. Isolation of the virus was performed by injecting the suspension of the samples into the allantoic fluid of fertilized eggs, and NDV was detected in the achieved allantoic fluids by reverse transcription polymerase chain reaction. The NDV was detected in 13 allantoic samples. The partial F gene sequences of 10 positive samples were investigated, and their genetic relationship with each other as well as with other isolates in the gene bank was marked. Consequently, subgenotype VII.1.1 (VIId) was in the locus of all 10 viruses. By the amino acid cleavage site sequences of F protein, 10 isolates were determined as velogenic NDV. Moreover, all sequences were similar to each other and other Iranian isolates. Furthermore, the 112RRQKR/F117 pattern was the main amino acid (aa) sequence in the F-protein Cleavage site for VIId genotype isolates. [ABSTRACT FROM AUTHOR]

Avian pasteurellosis (fowl cholera) is an important disease affecting domestic and wild birds all over the world. Although the capsular type A of Pasteurella multocida is mostly involved, other capsular types are occasionally incriminated. The present study aimed at investigating the effect of some adjuvants on immunogenicity and protectivity of P. multocida bacterin in chickens, compared to an Iranian commercial vaccine. Eight-week-old chicken pullets were double vaccinated with an interval of three weeks. Vaccine immunogenicity testing was conducted using an in-house indirect enzyme-linked immunosorbent assay and assessing serum antibody titers at 7, 14, and 21 days post-primary and 14 days post-secondary immunization. The possible adverse effects were recorded by a poultry-disease expert. For evaluating the vaccine protection rate, chickens were subjected to 2×Lethal Dose 50%of a virulent P. multocida strain two weeks post-secondary immunization. The rate of live and normal animals was regarded as protection rate 7days after the exposure. The findings showed that oil adjuvants Montanide ISA 70-and Montanide ISA 71-containingvaccines (with or without saponin) caused a powerful immune reaction than the aluminum adjuvanted vaccine and commercial vaccine (P<0.05). Significant protection against challenge was merely induced by the oil adjuvanted vaccines (P<0.05). The majority of the studied chickens showed inflammation at the injection site (yellow) throughout the trial. Vaccines made by Montanide ISA 70 and Montanide ISA 71 are novel and effective inactivated vaccines that are able to cause significant protection to fowl cholera disease. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Razi Institute is the property of Institut Razi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archives of Razi Institute is the property of Institut Razi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Razi Institute is the property of Institut Razi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archives of Razi Institute is the property of Institut Razi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archives of Razi Institute is the property of Institut Razi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archives of Razi Institute is the property of Institut Razi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study was conducted because of influence of prebiotics (alphamune) and symbiotic (biomin) on histometrical development of small intestine and lymphatic tissue of caecal tonsil have been not reported on broiler chicken. In this study, different parts of small intestine and caecal tonsil, which is a major area of gut associated lymphatic tissue (GALT) in chicken were selected. One hundred and twenty-five 1-day-old broiler chicks were divided into 3 groups: 1) Control group which were fed only by basal diet, 2) Alphamune group which were fed basal diet supplemented with prebiotic (0.5 kg/ton alphamune), and 3) Biomin group, fed basal diet supplemented with symbiotic (1 kg/ton biomin). At the end of 42 days, 15 chicks (5 chicks from each group) were selected for histomorphometrical study. The samples were taken from different parts of small intestine (duodenum, jejunum and ileum) and caecal tonsils and fixed in 10% formalin. The 5-6 μ sections were made by paraffin embedding method and stained by H&E. The results showed that although alphamune and biomin have a significant improvement on histomorphological structure of small intestine (more significant changes were seen in duodenum) and lymphatic tissue of caecal tonsil, the biomin has a more significant improvement. Villous height and thickness, the number of goblet cells, number and depth of intestinal crypt, density and area of aggregated lymphatic tissue were increased more significantly in biomin group (P<0.05). The knowledge obtained from this study showed that alphamune and biomin are considerable feed additives instead of antibiotic for improvement of histomorphological structure of small intestine and its associate lymphatic tissue. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the occurrence of Mycobacterium avium subspecies avium (MAA) on infected lofts of domestic pigeons, molecular identification, isolation, and necropsy findings. The study conducted the polymerase chain reaction (PCR) assay to test the acid fast basil isolate targeting 16S rRNA, IS1245, and IS901 genes. Results showed that the basis of frequency of necropsy lesions, clinical signs, isolation and identification of MAA from pigeons was high.

Background: Coccidiosis is an intestinal disease of chickens caused by various species of protozoan parasites within the genus Eimeria. Diagnosis and genetic characterization of different species of Eimeria are central to the prevention, surveillance, and control of coccidiosis. The aim of this study was to detect different chicken Eimeria species from several areas in Khuzestan, southwest Iran. Methods: From February to September 2008, PCR assay as well as parasitological examinations was applied for the identification of field isolates of Eimeria parasites around Ahvaz, center of Khuzestan, southwest Iran. Data were analyzed by the Kappa statistic test. Results: Eimeria maxima, E. necatrix, E. tenella, E. acervulina and E. mitis were detected in this study. The prevalence of Eimeria spp. was 31.5% (126 of 400) and E. tenella was the most prevalent species in Khuzestan. Based on the Kappa statistical test, a good correlation between the results of PCR and traditional biometrical methods was only observed for E. maxima. Conclusion: The present study is the first on the prevalence of Eimeria species in Khuzestan, based on the molecular findings. We believe that traditional methods are not sufficiently reliable for specific diagnosis of Eimeria species in chickens and PCR based amplification of DNA sequence of parasite, could resolve this problem. [ABSTRACT FROM AUTHOR]

The article presents a study which compared the effect of probiotic and enzyme on the performance of broiler chicks fed with corn soybean meal based diet. It analyzed the significant effect of probiotic at first three weeks on the performance of broiler chicks under heat stress condition. Results showed that supplementation of broiler ration with probiotic combined with enzyme is more effective compared to only enzyme.

Background: Ornithobacterium rhinotracheal (ORT) infects numerous birds, particularly chickens and turkeys. ORT is an emerging bacterial pathogen of global concern in the poultry industry. As ORT is rapidly spreading throughout commercial poultry, it requires intensive studies of its epidemiology, diagnostic procedures, molecular typing, virulence genes and antimicrobial resistance., Objectives: The present study was conducted in isolation and identification of ORT from slaughtered turkeys., Methods: Cleft palate swabs of 200 were collected from slaughtered turkeys and cultured on blood agar. ORT was characterized using biochemical tests and PCR targeting the ORT 16S rRNA gene. Virulence genes of isolates were determined targeting adenylate kinase (adk), copA and virulence-associated protein D (vapD) genes. Additionally, diversity of ORT isolates was performed by enterobacterial repetitive intergenic consensus (ERIC) and RAPD PCR. Disk diffusion was used to determine the antibiotic sensitivity of the isolates., Results: ORT was identified in 23 (11.5%) samples using both the biochemical tests and PCR. The result of detecting virulence genes showed that all the isolates (23: 100%) had the adk gene, whereas two (8.7%) isolates had the copA gene, and seven (30.43%) isolates had the vapD gene. Molecular typing of isolates revealed 21 different patterns by RAPD PCR assay using M13 primer and 20 distinct patterns by ERIC PCR test. Both ERIC and RAPD PCR were distinctive methods for investigating the genetic diversity of ORT isolates. The antibiotic resistance test showed that 18 (78.26%) isolates were resistant to gentamicin, amikacin, cefazolin, streptomycin and penicillin. All isolates (100%) were resistant to cloxacillin and fosfomycin., Conclusions: This study showed the prevalence of ORT in turkey and high resistance of this bacterium to many common veterinary antibiotics. Moreover, both ERIC and RAPD PCR are distinctive methods for investigating the genetic diversity of ORT isolates. These data may help monitor antibiotic resistance and typing of ORT in epidemiological studies and serve as the foundation for designing region-specific vaccines for future use., (© 2024 The Author(s). Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Influenza viruses can multiply in quails and be transmitted to other animal species. As vaccination reduces virus shedding in chickens, the effect of the killed H9N2 avian influenza virus (AIV) on tissue distribution and virus shedding was evaluated in quails. One hundred 20-day-old quails were divided into six equal groups, kept in separate pens, and fed ad libitum. Before vaccination, blood samples were randomly collected from the wing veins. Four groups were vaccinated with the inactivated H9N2 Razi Institute vaccine at 21 days subcutaneously at the back of neck. Three weeks later, two groups were re-vaccinated. Two weeks later, at the age of 56 days, three groups were challenged with 100 μL of allantoic fluid containing 10 5 EID 50 H9N2 through the oculonasal route. Blood samples were collected from quails at 42, 56, 63, and 70 days from each group to determine AIV antibodies by the hemagglutination inhibition test. Three quails were randomly selected and euthanized from each group on days 1, 3, and 6 post-inoculation (PI). Tissue samples were collected, and the RT-PCR test was performed. No clinical signs or gross lesions existed in any of the groups during the experiment. However, the virus was detected in different tissues on the first, third, and sixth days after the challenge in unvaccinated challenged birds. Virus detection was significantly more frequent in the quails vaccinated once and challenged than in the twice-vaccinated challenged group ( P ≤0.05). On the third day of PI, the virus was detected in some organs of the challenged groups. On the sixth day of PI, the virus was detected only in the lungs of two unvaccinated and once-vaccinated challenged birds. It was concluded that the vaccination of quails against AIV H9 is necessary to protect them from clinical signs, as well as respiratory tract and intestine replication. Two-time vaccination significantly protects the respiratory and intestine tracts, compared to one-time vaccination ( P ≤0.05)., Competing Interests: The authors declare that they have no conflict of interest.

Newcastle disease (ND) is a highly contagious infection of many avian species, mainly chickens and turkeys, with a devastating impact on worldwide poultry production. This study was designed to examine the effect of virulent ND infection in turkey's tissues and the tissue tropism of the virus. During the previous study period, poults were inoculated at 32 days of age with 10 5 EID50 virulent Newcastle disease virus. Three poults on days 0, 1, 2, 3, 4, 6, 7, and 14 postinoculations (PI) were selected from each group. They were euthanized by intravenous sodium pentobarbital injection. After macroscopic observation, to histopathological and immunohistochemical studies, the spleen, bursa, cecal tonsils, intestine, proventriculus, lung, kidney, and brain were sampled. Clinically, the infected turkeys exhibited loss of appetite, severe depression, down on hock joint, white to greenish (sometimes bloody) diarrhea, nervous signs, and mild respiratory problems. Out of 45 birds inoculated, 9 (20%) died. Histopathological effects in lymphoid tissues included necrosis and penetration of mononuclear cells on day 4 PI, and subsequent follicular lymphoid depletion on days 6 and 8 PI was observed. Based on the immunohistochemical test, on day 3 in cecal tonsils and spleen, and on day 8 PI, all of them were positive for virus antigen. In conclusion, the NDV circulating in Iranian chicken flocks has the potential to cause severe illness in commercial turkeys., (© 2021. Sociedade Brasileira de Microbiologia.)

Background: Newcastle disease, is one of the most important diseases of the poultry industry, has many economic losses. The aim of this study was to isolate and determine the molecular identity of Newcastle disease virus in 40 broiler flocks with respiratory symptoms in four provinces of Iran., Methods and Results: Samples of farms with respiratory symptoms were collected from different regions of Isfahan, East Azerbaijan, Golestan, and Khuzestan provinces and inoculated into 9-day-old embryonated chicken eggs. The Reverse-transcription polymerase chain reaction (RT-PCR) was performed to detect the Newcastle disease virus in allantoic fluid. Of the 40 flocks, the virus was isolated and identified in 16 flocks. The PCR products of 16 isolates were sequenced, and a phylogenetic tree was drawn. Accordingly, six isolates were in genotype II and ten isolates were in subgenotype VII.1.1 (VIId) of class II., Conclusion: Both genotypes were present in all four provinces. The isolates of Khuzestan province showed the greatest diversity compared to the other three provinces. The similarity of isolates belonging to genotype II in this study was observed with Pakistan, China, and Nigeria, and other isolates were similar to previous isolates in Iran. Also, the highest amino acid sequence in the F-protein cleavage site was 112RRQKR/F117 for VII.1.1 (VIId) genotype isolates and 112GRQGR/L117 for II genotype isolates., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

Avian mycobacteriosis is an important disease of birds and is most often caused by Mycobacterium avium or Mycobacterium genavense. However, little information on the hematologic changes associated with this infectious disease in pigeons has been published. The aim of this investigation was to compare the hematologic parameters of domestic pigeons (Columba livia var. domestica) naturally infected with M avium subsp. avium (MAA) with clinically healthy pigeons. Blood samples were collected from 12 pigeons with suspected mycobacteriosis and 12 clinically healthy pigeons. All the birds with suspect infections were necropsied, and affected organs were cultured and examined on histopathology for mycobacteriosis. Total leukocyte and erythrocyte counts were performed on each blood sample with the Natt and Herrick method using a Neubauer hemocytometer. White blood cell (WBC) differential counts were performed on Giemsa-stained blood smears. Packed cell volumes (PCVs) were measured using the microhematocrit technique. Hemoglobin concentrations were measured with a spectrophotometer using the cyanomethemoglubin method. Mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentrations (MCHCs), and mean cell volumes (MCVs) were calculated manually. All of the infected birds had typical histopathologic findings of avian mycobacteriosis, which were confirmed using microbiologic and molecular methods to detect MAA. The hematologic data from the two groups were compared. The total WBC, heterophil, lymphocyte, and monocyte counts were significantly higher, and the PCV, HGB, MCH, and MCHC values were significantly lower in the infected birds compared with the clinically healthy pigeons., (© 2021 American Society for Veterinary Clinical Pathology.)

Infectious Bronchitis (IB) is an acute, highly contagious disease associated with respiratory signs in young chickens and reduced egg production and quality in layers. The purpose of this study was to isolate and identify the infectious bronchitis virus in broiler flocks with respiratory diseases in four provinces of Iran. The specimens from forty IB suspected flocks from different regions of Isfahan, East Azerbaijan, Golestan, and Khuzestan provinces were collected, and the trachea, lung, and cecal tonsils were sampled. The samples were inoculated into 9- to 11-day-old embryonated chicken eggs. After collecting the allantoic fluid, RT-PCR was carried out to detect IB viruses. The results showed that IBVs were isolated from 30% of the flocks in these four provinces. The positive samples, according to a partial S1 gene sequence, were more investigated. Comparing nucleotide and amino acid sequences showed that the four isolates had the most similarity to the Pakistani 793/B strain (GI-13 lineage). The three isolates had the most considerable similarity in amino acid and nucleotide sequences to Iraqi and Iranian QX-like viruses (GI-19 lineage). Two isolates had 96 to 98% resemblance to Iranian variant-2 (GI-23 lineage) isolates. One isolate was found to belong to the Massachusetts serotype (GI-1 lineage) having 100% similarity in its amino acid sequence to the Massachusetts serotypes in GenBank. The phylogenetic relationship of the isolates shows complexity and diversity concerning different sequences and geographical regions.

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.

Avian influenza (AI) is an acute infectious disease with worldwide significance causing extensive economic losses in the poultry industry. Avian influenza viruses (AIVs) belong to the family Orthomyxoviridae and categorized in the genus influenza virus A. These viruses have been isolated from more than 100 species of free-living birds. Migratory birds are considered as reservoirs for AIVs and are the major agents responsible for global outbreaks. The Passeriformes are found in most parts of the world and cover a variety of habitats from rural to urban areas. House sparrows are members of the family Passeridae and due to their free flying, are strongly associated with seabirds, indigenous, and industrial poultry. The aim of this study was to determine the role of house sparrows in AIV (H9N2) circulation in the Ahvaz region. The intestinal and tracheal samples were taken from 200 sparrows around Ahvaz during 2017. Reverse transcriptase-polymerase chain reaction (RT-PCR) was performed using specific primers in order to detect M and H9 genes of AIVs. The positive specimens in the PCR for the M gene were inoculated into 9-11-day-old embryonated chicken eggs via the allantoic fluid. The results showed that 11 out of 200 samples were positive for the two genes of M and H9. According to the findings of the present study, house sparrows are infected with H9N2 and pose a threat to commercial poultry. These birds may play a significant role in the transmission of AIV between wildlife and domestic animals. Therefore, this issue is important to be considered in preventive measurements., (Copyright © 2019, Archives of Razi Institute. Published by Kowsar.)

Infectious bursal disease virus (IBDV) in turkeys may result in immunosuppression, and inability of turkeys to resist nonpathogenic or less pathogenic organisms. A total number of 120 day-old commercial male turkeys were purchased and blood samples were collected from 20 day-old turkeys, remaining 100 were divided into four equal groups and kept in separated rooms. Groups 1 and 2 were infected with 10 4 CID 50 of IBDV via intra-bursal route on day 1; Groups 1 and 3 were each infected with 10 6 EID50 of AIV (H 9 N 2 ) via the oculo-nasal routes on day 30. All groups were vaccinated against Newcastle disease vaccine (NDV). Detection of avian influenza virus H 9 N 2 in trachea and cloaca swabs and in the tissues, was confirmed by Real-time polymerase chain reaction. Anti- NDV-AIV and anti-IBD titers were measured using HI and ELISA tests, respectively. The present study showed that infectious bursal disease changed the pathogenesis of (AIV) H 9 N 2 by affecting AI virus replication and resulted in an increase shedding due to prolonged duration of sever clinical signs. The extent of shedding and virus replication need further study., (© 2019 Urmia University. All rights reserved.)

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., (Copyright © 2018, Archives of Razi Institute. Published by Kowsar.)

Infectious bronchitis (IB) is a highly contagious disease involving mostly upper respiratory tract in chickens, leading to significant economic losses in the poultry industry worldwide. One of the major concerns regarding to IB is the emergence of new types of infectious bronchitis viruses (IBVs). The purpose of this study was to identify the IBVs isolated from Iranian broiler chickens with respiratory symptoms. Twenty-five broiler flocks around Ahwaz (southwest of Iran) were examined for IBV. The specimens including trachea, lung, liver, kidney, and ceacal tonsil, were collected from diseased birds and inoculated into chicken embryonated eggs. Harvested allantoic fluids were subjected to reverse transcription polymerase chain reaction (RT-PCR) using primers in order to amplify spike 1 (S1) gene of IBV. The RT-PCR products of four IBV isolates were sequenced. The results showed that from 25 examined flocks with respiratory disease, 12 flocks (48.00%) were positive for IBV. In phylogenetic analysis, our isolates were closely related to the QX-like viruses such as PCRLab/06/2012 (Iran), QX, HC9, HC10, CK/CH/GX/NN11-1, CK/CH/JS/YC11-1, CK/CH/JS/2010/13, CK/CH/JS/2011/2 (China), QX/SGK-21, QX/SGK-11 (Iraq) with nucleotide homology up to 99.00%. This study indicates the role of IBVs in the respiratory disorders of broiler flocks located in southwest Iran, and also the existence of a variant of IBV, which is distinguishable from the other Iranian variants., Competing Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.