avian infectious bronchitis virus

Routine molecular diagnostic testing by our laboratory, based on using a primer pair with conservative binding sites on the spike glycoprotein coding sequence, has indicated the recurring of a unique phylogenetic cluster of chicken infectious bronchitis viruses (IBV) in the Middle East since 2010. The nearly full-length S1 subunit of the spike gene phylogeny of selected strains, however, split up this grouping, suggesting potential recombination in the S1 gene. In order to clarify this, various bioinformatic analyses of the strains were carried out, which confirmed this supposition. Two patterns of recombination were found among the strains, one of which could also be identified in GenBank-deposited IBV sequences from the region. These findings demonstrate that IBV strains of different recombinant patterns occur simultaneously in the same geographic region and could circulate for an extended period of time, thus contributing to the knowledge on IBV evolution.

Corona viruses are a group of related viruses that cause diseases in mammals and birds. In humans, coronaviruses cause respiratory tract infections that can be mild, such as some cases of the common cold (among other possible causes, predominantly rhinoviruses), and others that can be lethal, such as SARS, MERS, and COVID-19. Symptoms in other species vary: in chickens, they cause an upper respiratory tract disease, while in cows and pigs they cause diarrhea. There are yet to be vaccines or antiviral drugs to prevent or treat human corona virus infections.

Poultry production has affected by multiple respiratory disease triggering serious economic losses in Egypt. In this study, the situation and genetic evolution of respiratory disease in Egypt during 2020 were studied. We collected 53 samples from infected flocks suffered from respiratory signs and variable mortality rate from nine governorates in Egypt during 2020. The collected samples were examined for detection of respiratory disease viruses (Avian influenza virus (AIV), Infectious bronchitis virus (IBV), and Newcastle disease virus (NDV)) by rRT-PCR. The single infection was confirmed in 90.6% (37.7% I. B, 30.2% AIV (H5N8), 9.4% I. B and 5.7% NDV) and co-infection of HPAIV (H5N8) + I.BV and LPAIV (H9N2) +IBV were detected in 3.8% in nine governorates. The HA gene of HPAIV (H5N8) were cluster to clad 2.3.4.4.1b in new branch with characteristic specific mutations especially in T140A in antigenic site A and R72S in the receptor binding site when comparing with A/duck/Egypt/F446/20...

Infectious Bronchitis (IB) is highly contagious and acute, with economically importance disease of poultry. 185 samples including tracheal swab and faecal swab were collected from apparently healthy and infected birds with respiratory disorders. An attempt made to isolate the virus through inoculation of specific pathogen free embryonated egg (SPFEE) as cultural medium. The embryo showing dwarfism were identified and subjected to molecular diagnosis. Reverse transcription-polymerase chain reaction (RT-PCR) was used to amplify N-Protein and sequenced. Factors responsible for prevalence of IB in desi chicken were studied. Out of 185 samples 7 samples showed dwarfism in SPFEE. 4 out of 7 samples, found positive for IBV by RT-PCR.

Infectious bronchitis virus (IBV) is a major economic problem in commercial chicken farms with acute multiple-system infection, especially in respiratory and urogenital systems. A live-attenuated and killed vaccine is currently immunized to control IBV infection; however, repeated outbreaks occur in both unvaccinated and vaccinated birds due to the choice of inadequate vaccine candidates and continuous emergence of novel infectious bronchitis (IB) variants and failure of vaccination. However, similar clinical signs were shown in different respiratory diseases that are essential to improving the diagnostic assay to detect IBV infections. Various risk factors involved in the failure of IB vaccination, such as various routes of application of vaccination, the interval between vaccinations, and challenge with various possible immunosuppression of birds are reviewed. The review article also highlights and updates factors affecting the diagnosis of IBV disease in the poultry industry with...

Avian infectious bronchitis virus (IBV) is causing major economic losses to the poultry industry. The analysis of the S1 gene has been used to determine IBV genotype. The aim of this study was genotyping of IBVs circulating among the Iranian broiler flocks in the period between 2015 to 2017. Trachea samples from 278 broiler flocks were collected from broiler farms in eight provinces of Iran. After Real-time RT-PCR, IBV-positive samples were further characterized based on S1 gene. The results of the Real-time RT-PCR showed that 52.16% of flocks were IBV positive. Four genotypes were detected and the frequency of occurrence rates of IS-1494-like, 793/B, QX and Massachusetts IBV genotypes were 70.34%, 19.31%, 7.58% and 2.75%, respectively. Sequence analysis revealed that nucleotide identities within IS-1494-like group ranged between 98.86-100%, while each of the QX, Massachusetts and 793/B groups were 98.05-100%, 98.20-100% and 93.29-100% respectively. These results show that the IS-1494-like IBV is the dominant IBV genotype in Iran. Proper control strategies are essential to overcoming the high frequency of occurrence of IS-1494-like IBV. The phylogenetic relationship of the strains with respect to different sequences and geographical regions displayed complexity and diversity. Further studies are needed and should include the isolation and full-length molecular characterization of IBV in Iran.

The aim of the study is to develop the optimised parameters of electrochemical DNA biosensors for the specific detection of the Infectious Bronchitis Virus (IBV) in chickens. The ultimate goal is to further create a highly sensitive and specific biosensor that can be used for on-site monitoring of IBV on poultry farms. Methodology and results: In this study, an electrochemical DNA biosensor was developed for detecting a specific sequence in the IBV genome. The process involved attaching a NH2-ssDNA probe to a gold electrode, followed by hybridization with the target DNA. Various parameters like buffer, pH, scan rate, incubation time, redox indicators and temperature were optimised using cyclic voltammetry. The probe DNA was designed to enhance hybridization efficiency, which was assessed by measuring current signals. The biosensor, under optimal conditions, demonstrated high sensitivity and specificity when tested with different sequences, including complementary, non-complementary and mismatched ones. Cross-reactivity studies against non-IBV viruses showed distinguishable current signals. These findings have implications for developing a portable on-site IBV monitoring device for use on farms. The optimised parameters and specificity of the electrochemical DNA biosensor suggest its potential for the development of a portable device for on-site monitoring of IBV on poultry farms. This device could prove to be a valuable tool for the early detection of IBV, helping to prevent further spread of the disease. However, it's essential to conduct further research to ensure the practicality and accuracy of the biosensor in real-world farm settings.

An infectious bronchitis virus Arkansas DPI (Ark DPI) virulent strain was sequenced, analyzed and compared with many different IBV strains and coronaviruses. The genome of Ark DPI consists of 27,620 nucleotides, excluding poly (A) tail, and comprises ten open reading frames. Comparative sequence analysis of Ark DPI with other IBV strains shows striking similarity to the Conn, Gray, JMK, and Ark 99, which were circulating during that time period. Furthermore, comparison of the Ark genome with other coronaviruses demonstrates a close relationship to turkey coronavirus. Among non-structural genes, the 5'untranslated region (UTR), 3C-like proteinase (3CL pro ) and the polymerase (RdRp) sequences are 100% identical to the Gray strain. Among structural genes, S1 has 97% identity with Ark 99; S2 has 100% identity with JMK and 96% to Conn; 3b 99%, and 3C to N is 100% identical to Conn strain. Possible recombination sites were found at the intergenic region of spike gene, 3'end of S1 and 3a gene. Independent recombination events may have occurred in the entire genome of Ark DPI, involving four different IBV strains, suggesting that genomic RNA recombination may occur in any part of the genome at number of sites. Hence, we speculate that the Ark DPI strain originated from the Conn strain, but diverged and evolved independently by point mutations and recombination between field strains.

Infectious bronchitis virus (IBV) causes highly contagious respiratory or urogenital tract diseases in chickens. The Maryland 27(Md27) strain was first isolated in 1976 from diseased chicken flocks in the Delmarva Peninsula region. To understand the genetic diversity and phylogenetic relationship of existing strains with Md27, the complete nucleotide sequence of the 3'end coding region (~7.2 kb) of Md27 was determined and compared with other IBV strains and coronaviruses. It has the same S-3-M-5-N-3' gene order, as is the case of other IBV strains. The spike gene of Md27 exhibits 97% identity with the SE17 strain. There are deletions at the spike gene, non-coding region between M and 5 genes, and at the 3'untranslated region (UTR), which is different from Ark-like strains. Phylogenetic analysis and sequence alignments demonstrate that Md27 is a chimera containing different gene segments that are most closely related to the SE17, Conn and JMK strains. This current study provides evidence for genomic mutations and intergenic recombination that have taken place in the evolution of IBV strain Md27.

A novel avian infectious bronchitis virus (IBV), Egypt/Qal/014p was isolated from 14-day-old broiler chickens with proventriculitis in Qaluobia province of Egypt in 2014. The isolate was identified by a real time RT-PCR targeting the nucleocapsid (N) gene. Sequence analysis of partial S1 gene of Egypt/Qal/014p had close relation with that of the Massachusetts prototypes. Comparisons nucleotide and amino acid sequence of partial S1 gene showed that the recent isolate had 98.2% and 95.2% nucleotide similarities and 96.8% and 91.4% amino acid similarities with the commonly used IBV vaccine Massachusetts strains H120 and M41 respectively. Egypt/Qal/014p had a unique amino acid substitution at residues 39 (Serine), 40 (Tyrosine), 41 (Lysine), 64 (Glutamate) and 69 (Valine) of the S1 proteins from H120 and M41. The cross-neutralization test revealed antigenic relatedness of Egypt/Qal/014p with Massachusetts serotypes. The commercial H120 vaccine conferred partial protection against proven...

The present study was designed to evaluate the protection induced by different vaccination programs against Thai QX-like infectious bronchitis virus (IBV). The chickens were divided into 5 groups, 16 chickens in each. Groups 1-4 were vaccinated with different regimes of vaccination program against IBV. Groups 5 did not receive IBV vaccine and served as a positive control group. At 1 day old, the chickens in groups 2 and 3 were vaccinated with QX vaccine whereas the chickens in group 4 were vaccinated with H120 vaccine. At 14 days old, revaccination was performed in group 2 with QX vaccine whereas groups 3 and 4 were vaccinated with a combined vaccine, Newcastle disease virus strain B1 combined with IB strain Massachusetts (Mass) and Connecticut (Conn) (B1/Mass/Conn). The chickens in group 1 were only vaccinated with QX vaccine at 7 days old. At 28 days old, the chickens in groups 1-5 were individually challenged with 10 4 EID 50 of Thai QX-like IBV (isolate THA80151). The protection was evaluated at 7 days post-inoculation. The results showed that the clinical signs of all vaccinated groups were lower (p<0.05) than those of the positive control group. Virus detection in the tracheas and the histopathological lesion score of the tracheas and kidneys of the vaccinated groups were not significantly different (p>0.05) from those of the positive control group. The body weights of the vaccinated groups excluding group 3 were not significantly different (p>0.05) from that of the positive control group. It is suggested that all of the vaccination programs used in this study offered clinical protection against Thai QX-like IBV, but they did not provide sufficient protection against virus infection and histopathological lesions in the tracheas and kidneys.

Infectious bronchitis virus (IBV) is the causative agent of avian infectious bronchitis, which is characterized by respiratory, reproductive, and renal signs. However, the role of IBV as an enteric pathogen in still controversial. In Brazil, antigenic groups of IBV divergent from the Massachusetts serotype used for vaccination schedules in that country have already been demonstrated. The present study aimed to assess the different genotypes of IBV in Brazilian commercial poultry flocks by partial sequencing of the S1 amino-terminus coding region using enteric contents as samples and examine their relationship with the vaccine serotype currently in use. Samples of enteric contents were taken as pools of five birds from each of 18 poultry farms (17 broiler and one laying farm) from five Brazilian states between 2002 and 2006. Birds were presenting watery diarrhea and poor general condition but were without respiratory, renal, or reproductive signs. Conventional antibacterial and anticoccidial therapies were unsuccessful and, furthermore, all samples proved negative for rotavirus, reovirus, and astrovirus. Eleven IBV samples were isolated in embryonated eggs and resulted in S1 sequences. Phylogenetic analysis showed that these segregated into an exclusive cluster, close to serotype D274, but distant from Massachusetts. Mean amino acid identity amongst these Brazilian strains was 94.07%; amongst these and serotypes D274, 4/91, and Massachusetts, mean amino acid identity was 77.17%, 69.94%, and 68.93%, respectively. In conclusion, the presence of genotype variant strains of IBV in Brazilian poultry flocks has been demonstrated and might be the reason for the unsuccessful control of IBV in Brazil. Furthermore, these results also strengthen the implications of IBV in enteric diseases of poultry. RESUMEN. Nota de Investigacio ´n-Caracterizacio ´n molecular de cepas del virus de bronquitis infecciosa aislados de contenidos intestinales de ponedoras y pollos de engorde en Brasil. El virus de bronquitis infecciosa es el agente causal del la bronquitis infecciosa aviar, que se caracteriza por la presencia de signos respiratorios, reproductivos y renales. Sin embargo, el papel del virus de bronquitis infecciosa como pato ´geno ente ´rico sigue siendo controvertido. En Brasil ya se han demostrado grupos antige ´nicos del virus de bronquitis infecciosa diferentes al serotipo Massachussets utilizado en los planes de vacunacio ´n. El objetivo del presente estudio fue identificar los diferentes genotipos del virus de bronquitis infecciosa presentes en las parvadas comerciales de Brasil, mediante secuenciacio ´n parcial del gen S1 utilizando muestras de contenidos intestinales y examinando su relacio ´n con los serotipos vacunales utilizados actualmente. Entre los an ˜os 2002 y el 2006 se tomaron muestras de contenido ente ´rico de grupos de cinco aves provenientes de 18 granjas avı ´colas (17 de pollos de engorde y una de ponedoras) pertenecientes a cinco estados de Brasil. Las aves presentaban diarrea acuosa y una mala condicio ´n general, pero no mostraban signos respiratorios, reproductivos o renales. Las terapias antibacteriales y anticoccidiales convencionales fallaron y adema ´s, todas las muestras resultaron negativas a rotavirus, reovirus y astrovirus. Once virus de bronquitis infecciosa fueron aislados en huevos embrionados de los cuales se obtuvo la secuencia del gen S1. Los ana ´lisis filogene ´ticos mostraron que todos los aislamientos se ubicaron en un grupo exclusivo, cercano al serotipo D274, pero distante del serotipo Massachussets. El promedio de identidad de aminoa ´cidos entre las cepas de Brasil fue de 94.07%. Entre estas cepas y los serotipos D274, 4/91 y Massachussets, el promedio de identidad de aminoa ´cidos fue de 77.17%, 69.4% y 68.93%, respectivamente. En conclusio ´n, se demostro ´la presencia de genotipos variantes de cepas del virus de bronquitis infecciosa en parvadas de aves dome ´sticas en Brasil, pudiendo ser esta la razo ´n de las fallas en el control del virus de bronquitis infecciosa en el paı ´s. Adema ´s, estos resultados refuerzan las implicaciones del virus de bronquitis infecciosa en enfermedades ente ´ricas de las aves.

The aim of this study was to investigate pathological lesions and the presence of of Israel variant 2 (IS /1494/06) genotype of infectious bronchitis virus (IBV) in chickens with visceral gout. Sudden deaths were observed in broiler breeders and layer hens belonging to two different flocks located in eastern Türkiye. Broiler chickens were previously vaccinated with a vaccine containing strains of IBV Massachusetts serotype, but no information was available about the vaccination history of laying hens. At necropsy, there was accumulation of white chalk-like material on the serosal surface of the heart, liver, spleen and air sacs. The kidneys were unilaterally or bilaterally enlarged and pale in color and, ureters were also enlarged. Pooled organ samples from diseased chickens and kidneys alone were examined by virus isolation, real-time reverse transcription polymerase chain reaction (rRT-PCR), nucleotide sequencing analysis and histological methods. Israel variant 2 genotype of IBV ...

Avian infectious bronchitis (IB) is a highly contagious disease of poultry with high economic importance. Caused by avian infectious bronchitis virus (IBV), it is transmitted by direct and indirect contact through aerosol or fecal means. Although IB is considered as respiratory disease, various strains of IBV affect the renal as well as the reproductive system. The economic importance of disease is due to lower egg production, poor hatchability of eggs, and decreased quality of the egg, weight loss, growth retardation, and high condemnation rates in meat-type birds. Although the prevalence of IB is lower in Nepal (&gt;1%), it is ranked second as a disease which claims most livestock unit in the world. There is no specific treatment for IB but live and inactivated vaccines are available for the prevention and control of the virus. The lack of research in the infectious bronchitis virus can cause production losses in poultry sector due to the evolution of resistant virus strain in our...

Coronavirus disease 2019 (COVID-19) which causes severe acute respiratory syndrome (SARS) was named as SARS-CoV-2 to distinguish it from the previous SARS-CoV. The rate of acute respiratory distress syndrome (ARDS) is 19.6% in patients with COVID-19 pneumonia and has increased to 61.1% during the time of transfer to intensive care unit (ICU). 2 This ratio is getting higher in non-survivors (81%) and ARDS is becoming a large concern of death in COVID-19. Other remarkable findings which are linked to the severity of disease and the risk of mortality in COVID-19 is the increased level of D-dimer. Increment in the levels of D-dimer, Fibrin Degradation Product (FDP) and decrement in antithrombin (AT) has been seen in patients with COVID-19. Changes in D-dimer and FDP were prominent in severe disease as compared to the mild group. Thrombin time has been detected as shorter in critical patients compared to controls. Prothrombin time and D-dimer values at hospital admission have been shown to be higher in patients who need ICU during the disease process compared to non-ICU patients. Increased levels of D-dimer have been described as risk factors for development of ARDS and especially for death. Hospital death has been found to be associated with levels greater than 1 mg/mL of D-dimer on admission. 7 Gao et al described a cut off value for D-dimer as 0.28 ng/L to predict the severity of disease. 8 Overt-disseminated intravascular coagulation was determined in 71.4% of non-survivors compared to 0.6% of survivors in later stages of COVID-19 pneumonia. 9 Anticoagulant treatment with unfractionated heparin and low molecular weight heparin was shown to decrease mortality. Our hypothesis is that probable mechanisms for the increased D-dimer in COVID-19 may be related to virus life cycle. The apoptotic processes target the endothelial cells of the vascular structure resulting in triggered coagulopathy and the ultimate result of increased D-dimer. Apoptosis is a programmed cell death and has a critical role in the life cycle of viruses. Viruses can't live without a host cell

Coronavirus disease 2019 (COVID-19) which causes severe acute respiratory syndrome (SARS) was named as SARS-CoV-2 to distinguish it from the previous SARS-CoV. The rate of acute respiratory distress syndrome (ARDS) is 19.6% in patients with COVID-19 pneumonia and has increased to 61.1% during the time of transfer to intensive care unit (ICU). 2 This ratio is getting higher in non-survivors (81%) and ARDS is becoming a large concern of death in COVID-19. Other remarkable findings which are linked to the severity of disease and the risk of mortality in COVID-19 is the increased level of D-dimer. Increment in the levels of D-dimer, Fibrin Degradation Product (FDP) and decrement in antithrombin (AT) has been seen in patients with COVID-19. Changes in D-dimer and FDP were prominent in severe disease as compared to the mild group. Thrombin time has been detected as shorter in critical patients compared to controls. Prothrombin time and D-dimer values at hospital admission have been shown to be higher in patients who need ICU during the disease process compared to non-ICU patients. Increased levels of D-dimer have been described as risk factors for development of ARDS and especially for death. Hospital death has been found to be associated with levels greater than 1 mg/mL of D-dimer on admission. 7 Gao et al described a cut off value for D-dimer as 0.28 ng/L to predict the severity of disease. 8 Overt-disseminated intravascular coagulation was determined in 71.4% of non-survivors compared to 0.6% of survivors in later stages of COVID-19 pneumonia. 9 Anticoagulant treatment with unfractionated heparin and low molecular weight heparin was shown to decrease mortality. Our hypothesis is that probable mechanisms for the increased D-dimer in COVID-19 may be related to virus life cycle. The apoptotic processes target the endothelial cells of the vascular structure resulting in triggered coagulopathy and the ultimate result of increased D-dimer. Apoptosis is a programmed cell death and has a critical role in the life cycle of viruses. Viruses can't live without a host cell

Human SARS-CoV-2 and avian infectious bronchitis virus (IBV) are highly contagious and deadly coronaviruses, causing devastating respiratory diseases in humans and chickens. The lack of effective therapeutics exacerbates the impact of outbreaks associated with SARS-CoV-2 and IBV infections. Thus, novel drugs or therapeutic agents are highly in demand for controlling viral transmission and disease progression. Mesenchymal stem cells (MSC) secreted factors (secretome) are safe and efficient alternatives to stem cells in MSC-based therapies. This study aimed to investigate the antiviral potentials of human Wharton’s jelly MSC secretome (hWJ-MSC-S) against SARS-CoV-2 and IBV infections in vitro and in ovo. The half-maximal inhibitory concentrations (IC50), cytotoxic concentration (CC50), and selective index (SI) values of hWJ-MSC-S were determined using Vero-E6 cells. The virucidal, anti-adsorption, and anti-replication antiviral mechanisms of hWJ-MSC-S were evaluated. The hWJ-MSC-S sig...

The avian coronavirus infectious bronchitis virus (AvCoV-IBV) is recognized as an important global pathogen because new variants are a continuous threat to the poultry industry worldwide. This study investigates the genetic origin and diversity of AvCoV-IBV by analysis of the S1 sequence derived from 49 broiler flocks and 14 layer flocks in different regions of Turkey. AvCoV-IBV RNA was detected in 41 (83.6%) broiler flocks and nine (64.2%) of the layer flocks by TaqMan real-time RT-PCR. In addition, AvCoV-IBV RNA was detected in the tracheas 27/30 (90%), lungs 31/49 (62.2%), caecal tonsils 7/22 (31.8%), and kidneys 4/49 (8.1%) of broiler flocks examined. Pathologic lesions, hemorrhages, and mononuclear infiltrations were predominantly observed in tracheas and to a lesser extent in the lungs and a few in kidneys. A phylogenetic tree based on partial S1 sequences of the detected AvCoV-IBVs (including isolates) revealed that 1) viruses detected in five broiler flocks were similar to the IBV vaccines Ma5, H120, M41; 2) viruses detected in 24 broiler flocks were similar to those previously reported from Turkey and to Israel variant-2 strains; 3) viruses detected in seven layer flocks were different from those found in any of the broiler flocks but similar to viruses previously reported from Iran, India, and China (similar to Israel variant-1 and 4/91 serotypes); and 4) that the AVCoV-IBV, Israeli variant-2 strain, found to be circulating in Turkey appears to be undergoing molecular evolution. In conclusion, genetically different AvCoV-IBV strains, including vaccine-like strains, based on their partial S1 sequence, are circulating in broiler and layer chicken flocks in Turkey and the Israeli variant-2 strain is undergoing evolution. RESUMEN. Ana ´lisis filogenético y variación del gene S1 de virus de la bronquitis infecciosa detectados en pollos y gallinas de postura en Turquía. El coronavirus aviar conocido como el virus de la bronquitis infecciosa aviar (AvCoV-IBV), es reconocido como un patógeno global importante debido a que las nuevas variantes son una amenaza continua para la industria avícola en todo el mundo. En este estudio se investigó el origen genético y la diversidad de los virus de bronquitis de bronquitis mediante el ana ´lisis de la secuencia del gene S1 de virus derivados de 49 lotes de pollos y de14 lotes de ponedoras en diferentes regiones de Turquía. Se detectó ARN del virus de la bronquitis infecciosa en 41 (83.6%) lotes de pollos y en nueve (64.2%) de los lotes de ponedoras por un método de transcripción reversa y PCR en tiempo con sondas TaqMan. Adema ´s, se detectó ARN de virus de la bronquitis infecciosa en las tra ´queas 27/30 (90%), los pulmones 31/49 (62.2%), las tonsilas cecales 7/22 (31.8%), y riñones 4/49 (8.1%) de las parvadas de pollo de engorde examinadas. Se observaron lesiones patológicas, hemorragias, e infiltraciones mononucleares principalmente en las tra ´queas, en menor medida en los pulmones y en algunos riñones. Un a ´rbol filogenético basado en las secuencias parciales del gene S1 de los virus de la bronquitis detectados (incluyendo aislamientos) reveló que 1) los virus detectados en cinco lotes de pollos fueron similares a las vacunas Ma5, H120, M41; 2) los virus detectados en 24 lotes de pollos fueron similares a los virus previamente reportados en Turquía y a las cepas variantes 2 de Israel; 3) los virus detectados en siete parvadas de gallinas de postura fueron diferentes de los virus que se detectaron en todas las parvadas de pollos de engorde, pero similares a los virus que se habían reportado en Ira ´n, India y China (similares a la variante 1 de Israel y a los serotipos 4/91); y 4) que la cepa variante 2 de Israel que se encontró circulando en Turquía parecía que estaba experimentando evolución molecular. En conclusión, cepas del virus de la bronquitis infecciosa que fueron genéticamente diferentes, con base en la secuencia parcial del gene S1 y que incluyeron cepas similares a vacunas, se encontraron circulando en pollos de engorde y en gallinas de postura en Turquía y la cepa variante 2 de Israel se encontró experimentando evolución.

Infectious bronchitis (IB) is an economically important disease of chickens. Due to the emergence of new variants of infectious bronchitis virus (IBV), the control of IB has become a serious problem for the poultry industry worldwide. In the present study, the nucleocapsid gene (N) and 3&#39; untranslated region (UTR) of two IBVs isolated from Iranian poultry farms were sequenced and compared with other IBV strains. Based on nucleotide identity, the N gene and 3&#39; UTR sequences of Iranian IBVs showed 90% similarity to the commonly used IBV vaccine strains, H52 and H120. However, based on phylogenetic analyses, Iranian IBVs were found to cluster separately from the IBV vaccine strains used in Iran as well as other IBVs isolated in China, Australia and the United States. It was concluded that IBVs circulating in Iran are genetically distinct from IBV vaccine strains that have been used in Iran for many years. Therefore, it is important to develop a new vaccine based on these newly ...

A method based on Melting Temperature analysis of Hypervariable regions (HVR) of S1 gene within a RT-qPCR was developed to detect different genotypes of avian infectious bronchitis virus (IBV) and identify the Mass genotype. The method was able to rapidly identify the Mass genotype among IBV field isolates, vaccine attenuated strains and reference M41 strain in allantoic liquid and also directly in tissues. The RT-qPCR developed detected the virus in both tracheal and pulmonary samples from M41-infected or H120-infected birds, in a larger post-infection period compared to detection by standard method of virus isolation. RT-qPCR method tested provided a sensitivity and rapid approach for screening on IBV detection and Mass genotyping from IBV isolates.

The present study was designed to evaluate the protection induced by different vaccination programs against Thai QX-like infectious bronchitis virus (IBV). The chickens were divided into 5 groups, 16 chickens in each. Groups 1-4 were vaccinated with different regimes of vaccination program against IBV. Groups 5 did not receive IBV vaccine and served as a positive control group. At 1 day old, the chickens in groups 2 and 3 were vaccinated with QX vaccine whereas the chickens in group 4 were vaccinated with H120 vaccine. At 14 days old, revaccination was performed in group 2 with QX vaccine whereas groups 3 and 4 were vaccinated with a combined vaccine, Newcastle disease virus strain B1 combined with IB strain Massachusetts (Mass) and Connecticut (Conn) (B1/Mass/Conn). The chickens in group 1 were only vaccinated with QX vaccine at 7 days old. At 28 days old, the chickens in groups 1-5 were individually challenged with 10 4 EID 50 of Thai QX-like IBV (isolate THA80151). The protection was evaluated at 7 days post-inoculation. The results showed that the clinical signs of all vaccinated groups were lower (p<0.05) than those of the positive control group. Virus detection in the tracheas and the histopathological lesion score of the tracheas and kidneys of the vaccinated groups were not significantly different (p>0.05) from those of the positive control group. The body weights of the vaccinated groups excluding group 3 were not significantly different (p>0.05) from that of the positive control group. It is suggested that all of the vaccination programs used in this study offered clinical protection against Thai QX-like IBV, but they did not provide sufficient protection against virus infection and histopathological lesions in the tracheas and kidneys.

The present study was designed to evaluate the protection induced by different vaccination programs against Thai QX-like infectious bronchitis virus (IBV). The chickens were divided into 5 groups, 16 chickens in each. Groups 1-4 were vaccinated with different regimes of vaccination program against IBV. Groups 5 did not receive IBV vaccine and served as a positive control group. At 1 day old, the chickens in groups 2 and 3 were vaccinated with QX vaccine whereas the chickens in group 4 were vaccinated with H120 vaccine. At 14 days old, revaccination was performed in group 2 with QX vaccine whereas groups 3 and 4 were vaccinated with a combined vaccine, Newcastle disease virus strain B1 combined with IB strain Massachusetts (Mass) and Connecticut (Conn) (B1/Mass/Conn). The chickens in group 1 were only vaccinated with QX vaccine at 7 days old. At 28 days old, the chickens in groups 1-5 were individually challenged with 10 4 EID 50 of Thai QX-like IBV (isolate THA80151). The protection was evaluated at 7 days post-inoculation. The results showed that the clinical signs of all vaccinated groups were lower (p<0.05) than those of the positive control group. Virus detection in the tracheas and the histopathological lesion score of the tracheas and kidneys of the vaccinated groups were not significantly different (p>0.05) from those of the positive control group. The body weights of the vaccinated groups excluding group 3 were not significantly different (p>0.05) from that of the positive control group. It is suggested that all of the vaccination programs used in this study offered clinical protection against Thai QX-like IBV, but they did not provide sufficient protection against virus infection and histopathological lesions in the tracheas and kidneys.

The present study was designed to evaluate the protection induced by different vaccination programs against Thai QX-like infectious bronchitis virus (IBV). The chickens were divided into 5 groups, 16 chickens in each. Groups 1-4 were vaccinated with different regimes of vaccination program against IBV. Groups 5 did not receive IBV vaccine and served as a positive control group. At 1 day old, the chickens in groups 2 and 3 were vaccinated with QX vaccine whereas the chickens in group 4 were vaccinated with H120 vaccine. At 14 days old, revaccination was performed in group 2 with QX vaccine whereas groups 3 and 4 were vaccinated with a combined vaccine, Newcastle disease virus strain B1 combined with IB strain Massachusetts (Mass) and Connecticut (Conn) (B1/Mass/Conn). The chickens in group 1 were only vaccinated with QX vaccine at 7 days old. At 28 days old, the chickens in groups 1-5 were individually challenged with 10 4 EID 50 of Thai QX-like IBV (isolate THA80151). The protection was evaluated at 7 days post-inoculation. The results showed that the clinical signs of all vaccinated groups were lower (p<0.05) than those of the positive control group. Virus detection in the tracheas and the histopathological lesion score of the tracheas and kidneys of the vaccinated groups were not significantly different (p>0.05) from those of the positive control group. The body weights of the vaccinated groups excluding group 3 were not significantly different (p>0.05) from that of the positive control group. It is suggested that all of the vaccination programs used in this study offered clinical protection against Thai QX-like IBV, but they did not provide sufficient protection against virus infection and histopathological lesions in the tracheas and kidneys.

The infectious bronchitis virus (IBV) is one of the most important Coronaviridae viruses, infecting the upper respiratory tract of chickens and leading to considerable losses in the poultry industry across the globe. Many outbreaks have recently occurred among IBV-vaccinated chicken farms in the Diyala Governorate of Iraq resulting in significant economic losses. As a result, the purpose of the present study was to investigate whether IBV can be a source of infection spread in IBV-vaccinated commercial broiler flock farms in Diyala Governorate. In this regard, ELISA was used as a serological test and RT-PCR as a molecular detection technique. Serum samples were collected from chickens suspected of IBV at 16 and 23 days of age. The results showed a significant increase of IgG antibodies in such serum samples at days 16 and 23 of age indicating the infections of the broilers with IBV. However, at the age of 2-3 weeks, the samples of kidney, liver, trachea, and lungs were collected fro...

Background and Aim: One of the primary pathogenic causes linked to economic losses in the chicken business is the infectious bronchitis virus. This virus exploited its S (spike) gene-encoded protein to hook into the host receptor. The biological diversity of the viral S gene may be linked to the chicken industry&#39;s vaccination status. Recently, the virus was detected in broilers of six farms located in different districts of Diyala Governorate by the use of RT-PCR. The current study aimed to explore the pattern of biological diversity of infectious bronchitis viruses based on the possibility of genetic variations of the S gene. Materials and Methods: Ten tissue samples were collected from broilers of six farms located in different districts of Diyala Governorate and named R1 to R10. The chickens were recently vaccinated, but naturally infected with infectious bronchitis virus; a particular RT-PCR fragment partially encompassing the coding domains of the S gene was recently obtain...

Background and Aim: Avian coronavirus has a wide range of hosts, from chickens and turkeys to wild birds. This virus causes an economically and, possibly, environmentally, important loss in the poultry industry. Therefore, research into the avian coronavirus in various species of birds is required. The Eclectus parrot (Eclectus roratus) is an endemic bird to Indonesia and Northern Australia and often kept as pets. At present, there has been limited information about avian coronavirus infection among birds. This study aimed to determine the presence of and to characterize avian coronavirus isolated from Eclectus parrots in Indonesia. Materials and Methods: Cloacal swab samples were taken from 10 healthy Eclectus parrots (E. roratus). Each isolate was propagated into specific pathogen-free embryonated chicken eggs. The presence of avian coronavirus was determined using three sets of primers targeting the 3&#39; untranslated region (3&#39;-UTR) of avian coronavirus (UTR41+/11–), the N ...

The emergence of new variant strains of the poultry pathogen infectious bronchitis virus (IBV) is continually reported worldwide, owing to the labile nature of the large single-stranded RNA IBV genome. High resolution melt curve analysis previously detected a variant strain, N1/08, and the present study confirmed that this strain had emerged as a result of recombination between Australian subgroup 2 and 3 strains in the spike gene region, in a similar manner reported for turkey coronaviruses. The S1 gene for N1/08 had highest nucleotide similarity with subgroup 2 strains, which is interesting considering subgroup 2 strains have not been detected since the early 1990s. SimPlot analysis of the 7.2-kb 3′ end of the N1/08 genome with the same region for other Australian reference strains identified the sites of recombination as immediately upstream and downstream of the S1 gene. A pathogenicity study in 2-week-old chickens found that N1/08 had similar pathogenicity for chicken respiratory tissues to that reported for subgroup 2 strains rather than subgroup 3 strains. The results of this study demonstrate that recombination is a mechanism utilized for the emergence of new strains of IBV, with the ability to alter strain pathogenicity in a single generation.

Infectious bronchitis viruses (IBVs) are group III coronaviruses that infect poultry worldwide. Genetic variations, including whole-gene deletions, are key to IBV evolution. Australian subgroup 2 IBVs contain sequence insertions and multiple gene deletions that have resulted in a substantial genomic divergence from international IBVs. The genomic variations present in Australian IBVs were investigated and compared to those of another group III coronavirus, turkey coronavirus (TCoV). Open reading frames (ORFs) found throughout the genome of Australian IBVs were analogous in sequence and position to TCoV ORFs, except for ORF 4b, which appeared to be translocated to a different position in the subgroup 2 strains. Subgroup 2 strains were previously reported to lack genes 3a, 3b and 5a, with some also lacking 5b. Of these, however, genes 3b and 5b were found to be present but contained various mutations that may affect transcription. In this study, it was found that subgroup 2 IBVs have undergone a more substantial genomic rearrangements than previously thought.

The avian coronavirus-infectious bronchitis virus (AvCoV-IBV) is recognized as an important avian pathogen, and new viral variants are a continuous threat to the poultry industry worldwide. Sensitive diagnostics and efficacious vaccines are necessary to combat IBV infections in chickens. The aim of this study was to produce recombinant N protein of IBV in the baculovirus system to use in ELISA diagnostic tests in order to enable the assessment of the sero-prevalence and risk of IBV infections in chickens in Turkey. For this, the gene encoding the N protein of the Beaudette strain of IBV was expressed using a recombinant baculovirus expression system. The recombinant N protein was purified using Ni-NTA affinity chromatography. An estimated 50-kDa recombinant protein corresponding to the expected molecular weight of IBV N including the 6xHis tag was detected using an anti-His monoclonal antibody. Specific immunoreactivity of the recombinant protein was confirmed by Western blot using ...

The avian coronavirus infectious bronchitis virus (AvCoV-IBV) is recognized as an important global pathogen because new variants are a continuous threat to the poultry industry worldwide. This study investigates the genetic origin and diversity of AvCoV-IBV by analysis of the S1 sequence derived from 49 broiler flocks and 14 layer flocks in different regions of Turkey. AvCoV-IBV RNA was detected in 41 (83.6%) broiler flocks and nine (64.2%) of the layer flocks by TaqMan real-time RT-PCR. In addition, AvCoV-IBV RNA was detected in the tracheas 27/30 (90%), lungs 31/49 (62.2%), caecal tonsils 7/22 (31.8%), and kidneys 4/49 (8.1%) of broiler flocks examined. Pathologic lesions, hemorrhages, and mononuclear infiltrations were predominantly observed in tracheas and to a lesser extent in the lungs and a few in kidneys. A phylogenetic tree based on partial S1 sequences of the detected AvCoV-IBVs (including isolates) revealed that 1) viruses detected in five broiler flocks were similar to the IBV vaccines Ma5, H120, M41; 2) viruses detected in 24 broiler flocks were similar to those previously reported from Turkey and to Israel variant-2 strains; 3) viruses detected in seven layer flocks were different from those found in any of the broiler flocks but similar to viruses previously reported from Iran, India, and China (similar to Israel variant-1 and 4/91 serotypes); and 4) that the AVCoV-IBV, Israeli variant-2 strain, found to be circulating in Turkey appears to be undergoing molecular evolution. In conclusion, genetically different AvCoV-IBV strains, including vaccine-like strains, based on their partial S1 sequence, are circulating in broiler and layer chicken flocks in Turkey and the Israeli variant-2 strain is undergoing evolution. RESUMEN. Ana ´lisis filogenético y variación del gene S1 de virus de la bronquitis infecciosa detectados en pollos y gallinas de postura en Turquía. El coronavirus aviar conocido como el virus de la bronquitis infecciosa aviar (AvCoV-IBV), es reconocido como un patógeno global importante debido a que las nuevas variantes son una amenaza continua para la industria avícola en todo el mundo. En este estudio se investigó el origen genético y la diversidad de los virus de bronquitis de bronquitis mediante el ana ´lisis de la secuencia del gene S1 de virus derivados de 49 lotes de pollos y de14 lotes de ponedoras en diferentes regiones de Turquía. Se detectó ARN del virus de la bronquitis infecciosa en 41 (83.6%) lotes de pollos y en nueve (64.2%) de los lotes de ponedoras por un método de transcripción reversa y PCR en tiempo con sondas TaqMan. Adema ´s, se detectó ARN de virus de la bronquitis infecciosa en las tra ´queas 27/30 (90%), los pulmones 31/49 (62.2%), las tonsilas cecales 7/22 (31.8%), y riñones 4/49 (8.1%) de las parvadas de pollo de engorde examinadas. Se observaron lesiones patológicas, hemorragias, e infiltraciones mononucleares principalmente en las tra ´queas, en menor medida en los pulmones y en algunos riñones. Un a ´rbol filogenético basado en las secuencias parciales del gene S1 de los virus de la bronquitis detectados (incluyendo aislamientos) reveló que 1) los virus detectados en cinco lotes de pollos fueron similares a las vacunas Ma5, H120, M41; 2) los virus detectados en 24 lotes de pollos fueron similares a los virus previamente reportados en Turquía y a las cepas variantes 2 de Israel; 3) los virus detectados en siete parvadas de gallinas de postura fueron diferentes de los virus que se detectaron en todas las parvadas de pollos de engorde, pero similares a los virus que se habían reportado en Ira ´n, India y China (similares a la variante 1 de Israel y a los serotipos 4/91); y 4) que la cepa variante 2 de Israel que se encontró circulando en Turquía parecía que estaba experimentando evolución molecular. En conclusión, cepas del virus de la bronquitis infecciosa que fueron genéticamente diferentes, con base en la secuencia parcial del gene S1 y que incluyeron cepas similares a vacunas, se encontraron circulando en pollos de engorde y en gallinas de postura en Turquía y la cepa variante 2 de Israel se encontró experimentando evolución.

Infectious bronchitis (IB) is a disease with significant economic impacts both on the costs of control strategies and on productive losses. Various vaccination protocols are applied, depending on homologous or heterologous protection against IB and finding the optimal balance between costs and benefits as a choice by a responsible veterinarian. The current case study aimed to demonstrate the efficacy of a heterologous vaccine combination against field IBV GI-23 (Variant 2) infection when vaccination quality was properly monitored. Two groups, each consisting of six flocks, were examined before and after improving the quality of IB vaccine application in the hatchery. These groups were vaccinated with H-120 and 1/96 vaccine strains for heterologous protection. The study involved field visits, necropsies, serology via ELISA, and oropharyngeal sampling for RT-PCR follow-up activities. Moreover, performance parameters including average body weight, feed conversion ratio, and 7 days plus total mortality were analyzed at the end of the production cycle at 40-45 days of age. Results indicated that the group with enhanced vaccination quality in the hatchery exhibited a significant decrease in IBV titers and an absence of IBV GI-23 field infection. Additionally, there was an improvement in performance data in terms of average body weight, FCR and total mortality. Hatchery vaccination proved to be more controllable and practical compared to traditional on-farm vaccination, ensuring better control of the vaccination process and massive coverage of the farm population.

Astroviruses have been associated with enteric and extra-intestinal disorders in many animal species, including chickens. Here, we describe the detection and characterisation of chicken astrovirus (CAstV) in broilers and its seroprevalence in broiler breeder flocks. Based on PCR protocol, viral confirmation was carried out on clinical tissue samples from broiler chickens suffering from uneven growth and poor performance. The tissues were molecularly detected for CAstV with differential diagnostic testing against the Newcastle disease virus, infectious bronchitis virus, avian nephritis virus, avian rotavirus, fowl adenovirus and avian reovirus. Polymerase gene-based phylogenetic analyses of the twenty samples detected positive for CAstV indicate they belong to Group I and are related to strains from the US, UK, India and Poland. From these 20 samples, CastV could be isolated from 3 samples upon inoculation in 5-day-old specific-pathogenfree (SPF) embryonated chicken eggs (ECE); virus-infected embryos showed dwarfing, haemorrhages, oedema and gelatinous lesions at harvest. The enzymelinked immunosorbent assay (ELISA)

Astroviruses have been associated with enteric and extra-intestinal disorders in many animal species, including chickens. Here, we describe the detection and characterisation of chicken astrovirus (CAstV) in broilers and its seroprevalence in broiler breeder flocks. Based on PCR protocol, viral confirmation was carried out on clinical tissue samples from broiler chickens suffering from uneven growth and poor performance. The tissues were molecularly detected for CAstV with differential diagnostic testing against the Newcastle disease virus, infectious bronchitis virus, avian nephritis virus, avian rotavirus, fowl adenovirus and avian reovirus. Polymerase gene-based phylogenetic analyses of the twenty samples detected positive for CAstV indicate they belong to Group I and are related to strains from the US, UK, India and Poland. From these 20 samples, CastV could be isolated from 3 samples upon inoculation in 5-day-old specific-pathogenfree (SPF) embryonated chicken eggs (ECE); virus-infected embryos showed dwarfing, haemorrhages, oedema and gelatinous lesions at harvest. The enzymelinked immunosorbent assay (ELISA)

Infectious bronchitis is an acute respiratory disease of poultry associated with reduced egg production and heavy economic losses in chicken flocks. Rabid and accurate detection of IB virus (IBV) is essential for controlling and preventing the infection. In this study, we developed a rapid, accurate, and instrument less assay to detect IBV. For the first time, reverse transcription-Recombinase polymerase amplification (RT-RPA) coupled with CRISPR/Cas13 (SHERLOCK) was used to rapidly visualize IBV. The novel assay was tested in timing, sensitivity, and specificity. The spike gene (S gene) was used as a target gene for detecting the virus. Three samples were used to optimize the assay; sample form confirmed infected chickens with IB, positive sample (full synthesis of S gene), and negative sample from free IB infected chickens. The results show that the Sherlock-based Cas13 platform is a highly specificity and sensitivity assay for detecting infectious bronchitis virus. The assay detected ten copies per µL of the input RNA. No false positives or cross-reactions were seen when bovine coronavirus (BCV) was used instead of IBV in the tested sample. Readout of the results needs just fifty minutes, including RNA extraction. Furthermore, No instrument was used, and amplification of the virus's nucleic acid was performed at room temperature. Sherlock-based Cas13 should clinically use for rapid diagnosis of infectious bronchitis in chickens. However, further studies and experiments are needed to perform the assay at the sample base without extraction of RNA.

Background Newcastle disease (ND) causes severe economic losses in poultry industry worldwide. Egyptian poultry industry suffered from severe economic losses since the isolation of Velogenic Newcastle disease virus (vNDV) genotype VIId in 2011 and up till now despite the use of different vaccination programs. So, this study aimed to isolate and characterize the vNDV from a total of 120 poultry flocks from ten provinces in the Egyptian Delta region with a history of respiratory manifestation, high mortalities or a decrease in egg production between 2015 and 2019. Seventy-three samples’ allantoic fluid (73/120, 60.8%) were positive for hemagglutination with chicken RBCs. These samples were submitted to molecular examination using qRT-PCR specific primers for AOAV-1, highly pathogenic avian influenza (HPAI-H5), low pathogenic avian influenza (LPAI-H9) and infectious bronchitis virus (IBV). Results Fifty samples (50/120: 41.6%) were confirmed positive for AOAV-1, based on genetic analys...

Bacteria of the genus Escherichia coli, cause Colibacillosis in poultry and are transmitted to humans through handling and/or consumption of contaminated products raising concern over food safety and spread of resistant bacteria. We determined proportion of pathological samples where E.coli was isolated and its antimicrobial susceptibility patterns. From 106 birds and148 organs, Escherichia coli was isolated in 65% organs with 20% susceptible to Ampicillin, 30% to Tetracycline, 10% to Cotrimoxazole, 20% to Streptomycin, 40% to Kanamycin, 60% to Gentamycin and 10% to Sulphamethoxazole. High proportions of E.coli in samples including resistance to common antibiotics was detected. A holistic approach for prevention, control and treatment of avian Colibacillosis embracing good management, prudent use of antibiotics and utilization of laboratory services are important in controlling infections and overuse of antibiotics reducing resistance development. Enhanced food safety and handling practices are important in preventing spread of the drug resistant genes to human populations.

Infectious bronchitis (IB) is a disease with significant economic impacts both on the costs of control strategies and on productive losses. Various vaccination protocols are applied, depending on homologous or heterologous protection against IB and finding the optimal balance between costs and benefits as a choice by a responsible veterinarian. The current case study aimed to demonstrate the efficacy of a heterologous vaccine combination against field IBV GI-23 (Variant 2) infection when vaccination quality was properly monitored. Two groups, each consisting of six flocks, were examined before and after improving the quality of IB vaccine application in the hatchery. These groups were vaccinated with H-120 and 1/96 vaccine strains for heterologous protection. The study involved field visits, necropsies, serology via ELISA, and oropharyngeal sampling for RT-PCR follow-up activities. Moreover, performance parameters including average body weight, feed conversion ratio, and 7 days plus total mortality were analyzed at the end of the production cycle at 40-45 days of age. Results indicated that the group with enhanced vaccination quality in the hatchery exhibited a significant decrease in IBV titers and an absence of IBV GI-23 field infection. Additionally, there was an improvement in performance data in terms of average body weight, FCR and total mortality. Hatchery vaccination proved to be more controllable and practical compared to traditional on-farm vaccination, ensuring better control of the vaccination process and massive coverage of the farm population.

Poultry production has affected by multiple respiratory disease triggering serious economic losses in Egypt. In this study, the situation and genetic evolution of respiratory disease in Egypt during 2020 were studied. We collected 53 samples from infected flocks suffered from respiratory signs and variable mortality rate from nine governorates in Egypt during 2020. The collected samples were examined for detection of respiratory disease viruses (Avian influenza virus (AIV), Infectious bronchitis virus (IBV), and Newcastle disease virus (NDV)) by rRT-PCR. The single infection was confirmed in 90.6% (37.7% I. B, 30.2% AIV (H5N8), 9.4% I. B and 5.7% NDV) and co-infection of HPAIV (H5N8) + I.BV and LPAIV (H9N2) +IBV were detected in 3.8% in nine governorates. The HA gene of HPAIV (H5N8) were cluster to clad 2.3.4.4.1b in new branch with characteristic specific mutations especially in T140A in antigenic site A and R72S in the receptor binding site when comparing with A/duck/Egypt/F446/20...

Background and Aim: The high prevalence of QX-like variant among Thai isolates poses a significant threat to poultry production. In this study, we evaluated the protective efficacy of commercially available heterologous infectious bronchitis virus (IBV) vaccines against the local Thai QX-like strain in specific-pathogen-free (SPF) chicks from Thailand. Materials and Methods: The experiment involved 100 SPF chicks divided into 4 arms. Arms I and II received the TAbic IB VAR (233A) and Ibird (1/96) vaccines, respectively, on day 1. After 10 days, both arms received the H120 vaccine. Arms III and IV were non-vaccinated positive and negative controls. Challenge infection was local Thai QX-like virus on birds of Arms I, II, and III, and negative control of Arm IV. Clinical signs of infectious bronchitis (IB) and IBV detection using reverse transcription polymerase chain reaction were assessed at 2, 4, and 6 days post-challenge (dpc). At 6 dpc, the birds were humanely euthanized for post-mortem examination with the ciliostasis test and histopathological analysis of the tracheas, lungs, and kidneys. Results: Virus shedding started at 4 dpc (33.3% positive) and reached 100% positivity at 6 dpc with obvious clinical respiratory symptoms in non-vaccinated-challenged birds. No detection of IBV in vaccinated-challenged arms. Ciliary activity scores were significantly lower in non-vaccinated-challenged birds at 23.64 (standard deviation [SD] ± 1.74) and 96.50 (SD ± 1.91) and 95.64 (SD ± 1.77), respectively (p = 0.05) than in vaccinated-challenged birds. The most remarkable histopathological changes were observed in non-vaccinated-challenged birds, with moderately severe changes in the trachea, lungs, and kidneys. On the other hand, birds in vaccinated-challenged arms showed no significant changes. Conclusion: This study demonstrated the efficacy of TAbic IB VAR (233A) or Ibird (1/96) vaccine combined with a Massachusetts serotype vaccine (H120) against the local Thai QX-like strain in SPF chicks, contributing valuable insights to the selection of suitable commercially available vaccines to combat the prevalent local QX-like strains in Thailand.

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Infectious bronchitis (IB) is a highly aggressive disease for poultry in terms of symptoms and economic losses, and the control of this disease is difficult if flocks are not protected against type-specific challenges by the Avian infectious bronchitis virus (IBV). This article summarizes data presented by the author at the Workshop on Infectious Bronchitis 2009 on IB and IBV, including future developments on the field.

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Poultry diseases are considered to be one of the most leading factors which are responsible for reducing both the total number and productivity of chickens. Infectious bronchitis virus is internationally important disease of high concern due its adverse effects on poultry production in different aspects. The Cross-sectional study was conducted from November, 2021 to June 2022 in Bishoftu town, Ethiopia with the aim of confirming the presence of infectious bronchitis virus (IBV) in the samples collected from suspected chicken through the combined result molecular, gross and histopathology. Depression with different severity, respiratory related signs, diarrhea and retardation in growth were the clinical signs which frequently seen and recorded in majority of them. Tissue (lungs, trachea and kidneys) and tracheal swab samples were collected from 40 chickens clinically suspected of infectious bronchitis virus. Among these 25 were from farm A and 10 were from farm B commercial poultry f...

Avian infectious bronchitis is a contagious viral disease, caused by avian infectious bronchitis virus (IBV), that leads to
severe losses in the poultry industry all over the world. Since the 1950s, IBV has circulated in the Middle East and North
Africa, and no tangible evidence has shown any effects of measures taken to control its spread or evolution. Furthermore,
new IBV variants are continually discovered. Although several genetic studies on IBV have been conducted, many IBV
strains from this region have either been misclassified or remain unclassified. The genotype 23 (GI-23) variant emerged and
has prevailed in the Middle East by continuously evolving through inter- and/or intra-genotypic recombination. The GI-23
genotype is currently enzootic throughout Europe and Asia. Although many studies of protection against the circulating
strains have been conducted, they have not been standardized according to regulatory requirements. In this review, we provide
an overview of the evolution and genetic diversity of IBV genotypes and a genetic classification of IBV strains, with
a focus on the GI-23 genotype. The high prevalence of IBV GI-23 strains necessitates the adoption of vaccination schemes
using GI-23-based vaccines.

The susceptibility of the chicken embryo related (CER) cell line to infectious bronchitis virus (IBV M41) was characterized after five consecutive passages in CER cells. Virus replication was monitored by cytopathic effect observation, electron microscopy, indirect immunofluorescence, and reverse transcription polymerase chain reaction (RT-PCR). At 96 h post-infection (p.i.), the cytopathic effect was graded 75% by cell fusion, rounding up of cells and monolayer detachment, and the electron microscopy image characterized by coronavirus morphology. Cytoplasmic fluorescence was readily observed by from 24 h p.i. onwards, and at all times the respective viral RNA from IBV-infected monolayers was demonstrated by RT-PCR. Extra-cellular virus was measured by virus titration performed on chicken kidney cells and embryonated chicken eggs, and respective titres ranged from 4.0 to 6.0 log 10 EID 50 /ml on embryonated chicken eggs, and from 2.0 to 6.0 log 10 TCID 50 /ml on both CER cells and chicken kidney cells studied from 24 to 120 h p.i. These results confirmed that the M41 strain replicated well in the CER cell line.

The characterization of the newly emerged variant strains in the Egyptian field is important for improving the control measures for avian infectious bronchitis virus (IBV) and understanding the cause of recent outbreaks. Four isolates of IBV were selected from the isolates bank of the Reference Laboratory for Veterinary Quality Control on Poultry Production (RLQP) from different provinces during 2010 and 2012. We conducted a comparison between the selected field isolates sequences, other Egyptian isolates published on the gene bank and the vaccinal strains of the commercial vaccines that are commonly used in Egypt. The sequencing of full length S1 gene (Spike 1 glycoprotein) was done and phylogenetic tree of Egyptian viruses was constructed; also nucleotide and amino acid identities were calculated. The results of phylogenetic tree of the Egyptian viruses showed that the Egyptian IBV can be grouped into three main groups (classic, IS/1494 like strains and new variant group).The amin...

Infectious bronchitis virus is characterised by an extreme degree of variability which deeply affects the first-choice control strategies against the disease. Each country tends to adopt its own protocols and even vaccine producers themselves can also adopt different strategies in attempts to confront local epidemiological concerns. In the present study, we tested the potential environmental persistence, transmission ability and replication capability of a non-directly administrated vaccine strain at a hatchery and during transportation. To this purpose, we examined a single hatchery, where combined vaccination (Mass-like plus 793B-like strains) is commonly administered following the protectotype concept, whereas a single broiler flock receives only the Mass priming. Two groups of solely Mass-primed chicks were kept in contact with chicks vaccinated with both strains, during hatchery procedures and transportation, respectively. A regularly vaccinated control group was selected and a...