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1.
Avian Pathol ; 51(3): 236-243, 2022 Jun.
Article in English | MEDLINE | ID: covidwho-1890506

ABSTRACT

RESEARCH HIGHLIGHTSIn 2019, there was a resurgence of NDV from sub-genotype VII.2 in Israel, in an already endemic area of sub-genotype VII.1.A mismatch at the 3' end of the reverse primer caused a diagnostic failure of the NDV virulence differentiation rRT-PCR assay.The 2019 NDV sub-genotype VII.2 virus is genetically close to viruses from Jordan (2018) and Pakistan (2015-2016).


Subject(s)
Newcastle Disease , Poultry Diseases , Animals , Chickens , Genotype , Israel/epidemiology , Newcastle Disease/epidemiology , Newcastle disease virus/genetics , Phylogeny , Point Mutation , Poultry Diseases/epidemiology
2.
J Virol ; 96(12): e0068622, 2022 Jun 22.
Article in English | MEDLINE | ID: covidwho-1874505

ABSTRACT

Infectious bronchitis virus (IBV), a γ-coronavirus, causes the economically important poultry disease infectious bronchitis. Cellular stress response is an effective antiviral strategy that leads to stress granule (SG) formation. Previous studies suggested that SGs were involved in the antiviral activity of host cells to limit viral propagation. Here, we aimed to delineate the molecular mechanisms regulating the SG response to pathogenic IBV strain infection. We found that most chicken embryo kidney (CEK) cells formed no SGs during IBV infection and IBV replication inhibited arsenite-induced SG formation. This inhibition was not caused by changes in the integrity or abundance of SG proteins during infection. IBV nonstructural protein 15 (Nsp15) endoribonuclease activity suppressed SG formation. Regardless of whether Nsp15 was expressed alone, with recombinant viral infection with Newcastle disease virus as a vector, or with EndoU-deficient IBV, the Nsp15 endoribonuclease activity was the main factor inhibiting SG formation. Importantly, uridine-specific endoribonuclease (EndoU)-deficient IBV infection induced colocalization of IBV N protein/dsRNA and SG-associated protein TIA1 in infected cells. Additionally, overexpressing TIA1 in CEK cells suppressed IBV replication and may be a potential antiviral factor for impairing viral replication. These data provide a novel foundation for future investigations of the mechanisms by which coronavirus endoribonuclease activity affects viral replication. IMPORTANCE Endoribonuclease is conserved in coronaviruses and affects viral replication and pathogenicity. Infectious bronchitis virus (IBV), a γ-coronavirus, infects respiratory, renal, and reproductive systems, causing millions of dollars in lost revenue to the poultry industry worldwide annually. Mutating the viral endoribonuclease poly(U) resulted in SG formation, and TIA1 protein colocalized with the viral N protein and dsRNA, thus damaging IBV replication. These results suggest a new antiviral target design strategy for coronaviruses.


Subject(s)
Coronavirus Infections , Endoribonucleases , Infectious bronchitis virus , Virus Replication , Animals , Antiviral Agents/pharmacology , Chick Embryo , Chickens , Coronavirus Infections/veterinary , Endoribonucleases/genetics , Infectious bronchitis virus/enzymology , Infectious bronchitis virus/physiology , Poultry Diseases/virology , RNA, Double-Stranded
3.
Avian Pathol ; 51(3): 244-256, 2022 Jun.
Article in English | MEDLINE | ID: covidwho-1873688

ABSTRACT

To achieve long term protection of laying and breeding hens against aberrant egg production caused by infectious bronchitis virus (IBV), a vaccination programme incorporating both live-attenuated and inactivated IBV vaccines is required. High quality IBV vaccines of both types are widely available, but the number of IBV variants of global importance continues to increase and it is not possible to develop vaccines against each one of them. Therefore, it is desirable to perform studies under controlled conditions to determine which IBV vaccine(s) provide the best protection for laying hens against different IBV challenges. Previous vaccination and challenge studies have shown that it is possible to obtain relevant data in a small number of laying hens housed under conditions of strict isolation. The present work extends this finding by investigating the efficacy, against challenge with five IBV strains of global importance, of an IBV vaccination programme including two live-attenuated IBV vaccines (Massachusetts and 793B types) and three different commercially available inactivated vaccines each containing antigen against at least one IBV strain. The results reported here confirm the importance of IBV vaccination for laying hens, show that efficient live priming makes a beneficial contribution to this protection and confirm that inactivated IBV vaccines contribute significantly to effective protection against at least the five IBV challenge strains used here. Furthermore, we provide data to support the "protectotype concept", long-established using different live-attenuated IBV vaccines in young chickens, is valid in broadening protection against IBV challenges in laying birds.RESEARCH HIGHLIGHTSIBV vaccination is essential as an aid in protecting laying hens against IBV infection.Live priming is a beneficial part of the IBV vaccination programme.IBV inactivated vaccine improves IBV protection.Heterologous IBV protection is confirmed in laying hens.


Subject(s)
Coronavirus Infections , Infectious bronchitis virus , Poultry Diseases , Viral Vaccines , Animals , Chickens , Coronavirus Infections/prevention & control , Coronavirus Infections/veterinary , Female , Vaccination/veterinary , Vaccines, Attenuated , Vaccines, Inactivated
4.
Res Vet Sci ; 147: 74-82, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-1873256

ABSTRACT

In and around poultry farms, high concentrations of endotoxins are found that have a negative impact on the health of farmers and local residents. However, little is known about the effects of chronic exposure to endotoxins on the health of poultry. The aim of this study was to identify effects of chronic exposure to airborne endotoxins (E. coli LPS) on the immune system, respiratory tract, disease susceptibility and welfare of broilers. Effects of high (HE) and low endotoxin (LE) concentrations on natural antibody titers (NAb), performance and behavior of broilers were determined. After treatment with a respiratory virus infection, infectious bronchitis virus (IBV), mRNA expression of cytokines and Toll-like receptor (TLR) 4 in the lung, tracheal ciliary activity and lesions in the respiratory tract were determined. Endotoxin affected the immune system and respiratory tract, where HE broilers tended to have lower IgM NAb binding Phosphorylcholine-conjugated to Bovine Serum Albumin, and higher interferon (IFN)-α mRNA expression and more lesions in the nasal tissue compared to LE broilers. Furthermore, HE broilers had higher TLR4 mRNA expression compared to LE broilers. However, endotoxin did not affect NAb levels binding Keyhole Limpet Hemocyanin, IFN-ß and interleukin-10 mRNA expression, IBV replication or lesions in the lung and trachea. HE and LE broilers further had similar body weight, but HE broilers showed numerically more passive behavior compared to LE broilers. In conclusion, chronic exposure to high airborne endotoxin concentrations affects components of the immune system and respiratory tract in broilers and could therefore influence disease susceptibility.


Subject(s)
Coronavirus Infections , Infectious bronchitis virus , Poultry Diseases , Animals , Chickens , Coronavirus Infections/veterinary , Disease Susceptibility/veterinary , Endotoxins/toxicity , Escherichia coli , Lung , RNA, Messenger/genetics
5.
J Virol ; 96(10): e0024122, 2022 05 25.
Article in English | MEDLINE | ID: covidwho-1868711

ABSTRACT

In this study, 232 class I Newcastle disease viruses (NDVs) were identified from multiple bird species at nationwide live bird markets (LBMs) from 2017 to 2019 in China. Phylogenetic analysis indicated that all 232 isolates were clustered into genotype 1.1.2 of class I on the basis of the fusion (F) gene sequences, which were distinct from the genotypes identified in other countries. Most of the isolates (212/232) were shown to have the typical F gene molecular characteristics of class I NDVs, while a few (20/232) contained mutations at the site of the conventional start codon of the F gene, which resulted in open reading frames (ORFs) altered in length. The isolates with ACG, CTA, and ATA mutations showed different levels of increased virulence and replication capacity, suggesting that these viruses may be transitional types during the evolution of class I NDVs from avirulent to virulent. Further evaluation of biological characteristics with recombinant viruses obtained by reverse genetics demonstrated that the ATG located at genomic positions 4523 to 4525 was the authentic start codon in the F gene of class I NDV, and the specific ATA mutations which contributed to the expression of F protein on the surface of infected cells were the key determinants of increased replication capacity and virulence. Interestingly, the mutation at the corresponding site of genotype II LaSota of class II had no effects on the virulence and replication capacity in chickens. Our results suggest that the alteration of virulence and replication capacity caused by specific mutations in the F gene could be a specific characteristic of class I NDVs and indicate the possibility of the emergence of virulent NDVs due to the persistent circulation of class I NDVs. IMPORTANCE The available information on the distribution, genetic diversity, evolution, and biological characteristics of class I Newcastle disease viruses (NDVs) in domestic poultry is currently very limited. Here, identification of class I NDVs at nationwide live bird markets (LBMs) in China was performed and representative isolates were characterized. A widespread distribution of genotype 1.1.2 of class I NDVs was found in multiple bird species at LBMs in China. Though most isolates demonstrated typical molecular characteristics of class I NDVs, a few that contained specific mutations at the site of the conventional start codon of the fusion gene with increased virulence and replication capacity were identified for the first time. Our findings indicate that the virulence of class I NDVs could have evolved, and the widespread transmission and circulation of class I NDVs may represent a potential threat for disease outbreaks in poultry.


Subject(s)
Newcastle Disease , Poultry Diseases , Animals , Chickens/virology , China/epidemiology , Codon, Initiator , Commerce , Epidemiological Monitoring/veterinary , Genotype , Newcastle Disease/epidemiology , Newcastle disease virus/genetics , Phylogeny , Poultry/virology , Poultry Diseases/epidemiology , Virulence/genetics
6.
Pol J Vet Sci ; 25(1): 45-50, 2022 Mar.
Article in English | MEDLINE | ID: covidwho-1856596

ABSTRACT

Infectious bronchitis (IB) is an important disease that causes severe economic loses in the poultry industry worldwide. Furthermore, the spread of new variants poses a challenge for diagnosis and control of the disease. This study investigated the situation of infectious bronchitis virus (IBV), specifically the Israel variant-2 (IS var-2) also known as GI-23 genotype, in Turkey. Between 2014 and 2019, 214 flocks vaccinated against H120 from Marmara, Western Black Sea, and Inner Anatolia were examined, with 127 (59.3%) flocks testing positive for IBV, of which 92 (72.4%) were positive for IS var-2. Of the latter samples, 60 were randomly selected and subjected to full S1 gene sequencing. The analysis indicated that the field strain in Turkey was located on the same branch as the GI-23 genotype, which is one of the most frequently observed wild-type cluster found in the Middle East. The DNA similarities between the GI-23 isolates from 2014 to 2019 were 99%. In conclusion, the IS var-2 genotype has been circulating in broiler flocks in Turkey. It is recommended that establishing the vaccine strategy it should be considered the current circulating strains for the prevention and control of the disease among poultry.


Subject(s)
Coronavirus Infections , Infectious bronchitis virus , Poultry Diseases , Animals , Chickens , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Coronavirus Infections/veterinary , Genotype , Infectious bronchitis virus/genetics , Israel , Phylogeny , Poultry Diseases/epidemiology , Turkey/epidemiology
7.
Microb Pathog ; 166: 105513, 2022 May.
Article in English | MEDLINE | ID: covidwho-1851791

ABSTRACT

IBV infection may lead to reduced egg production and poor egg quality in layer flocks. The DMV/1639 strain was recently identified as one of the most dominant IBV variants isolated from Canadian layer flocks with egg production problems. The current study aimed to investigate the immunopathogenesis of the Canadian DMV/1639 strain in laying chickens. Specific-pathogen-free (SPF) layers were infected at the peak of lay (29 weeks; n = 10) with an uninfected control group (n = 10). Egg production in the infected group dropped to 40% by the fifth day post-infection (dpi). Five birds from the infected and the control groups were euthanized at 5 and 10 dpi. Ovarian regression and shortened oviduct with marked histopathological changes were observed in the infected group at 10 dpi. An increase in the IBV viral load in reproductive tissues was accompanied by a significant recruitment (p < 0.05) of KUL01+ macrophages and CD4+ and CD8+ T cell subsets at 10 dpi. Additionally, anti-IBV antibody response was detected in serum and locally in the reproductive tract washes of the infected group. Overall, our findings contribute to the understanding of the pathogenicity of the Canadian DMV/1639 strain and the subsequent host responses in the reproductive tract of chickens.


Subject(s)
Coronavirus Infections , Infectious bronchitis virus , Poultry Diseases , Animals , Canada , Chickens/virology , Coronavirus Infections/veterinary , Poultry Diseases/virology
8.
Int Immunopharmacol ; 108: 108764, 2022 Jul.
Article in English | MEDLINE | ID: covidwho-1851316

ABSTRACT

The prevalence of avian infectious bronchitis virus (IBV) is still one of causes inducing severe losses of production in the poultry industry worldwide. Vaccination does not completely prevent IBV infection and spread due to immune failure and viral mutations. ForsythiaeFructus and its compounds have been widely used in a lot of prescriptions of the traditional Chinese medicine for a long history, and it is well-known as safety and efficiency in heat-clearing and detoxifying. This study aims to investigate the anti-IBV activity and mechanism of phillygenin. The results showed that phillygenin inhibited IBV replication by disturbing multiple stages of the virus life cycle, including viral adsorption, invasion, internalization, and release in Vero cells. After being treated with 100, 125 and 150 µg/mL phillygenin, the expression of G3BP1 was significantly increased and the phosphorylation of PKR/eIF2α was activated, which increased stress granule, thereby triggering the antiviral response in Vero cells. The anti-virus activity of PHI was decreased when G3BP1 was interfered by si-RNA, and G3BP1 was down-regulated when PKR/eIF2α was interfered by si-RNA. In conclusion, our findings indicate that phillygenin activates PKR/eIF2α pathway and induces stress granule formation to exert anti-IBV, which holds promise to develop into a novel anti-IBV drug. Further study in vivo is needed to explore phillygenin as a potential and effective drug to prevent IB in poultry.


Subject(s)
Coronavirus Infections , Infectious bronchitis virus , Poultry Diseases , Animals , Chlorocebus aethiops , DNA Helicases/metabolism , DNA Helicases/pharmacology , Eukaryotic Initiation Factor-2/metabolism , Eukaryotic Initiation Factor-2/pharmacology , Infectious bronchitis virus/physiology , Lignans , Poly-ADP-Ribose Binding Proteins , RNA , RNA Helicases/metabolism , RNA Helicases/pharmacology , RNA Recognition Motif Proteins , Vero Cells
9.
Poult Sci ; 101(5): 101760, 2022 May.
Article in English | MEDLINE | ID: covidwho-1829377

ABSTRACT

Infectious Bronchitis Virus (IBV) is one of the most important viral diseases which causes important economic losses in poultry industry. This study aimed to assess the seroprevalence, prevalence, and variants of IBV in broilers, layers, and broiler breeders´ farms of Gallus gallus species in Eastern Spain. Thus, 29, 16, and 14 flocks of broilers, layers and broiler breeders, respectively were analyzed. To assess seroprevalence, sera samples were analyzed by ELISA. Tracheal swabs and tissue samples were tested by PCR to know the prevalence and detect specific variants. An IBV seroprevalence of 100% was detected in the 3 productive orientations. According to PCR results, a prevalence of 38% in broilers, 44% in layers and 43% in broiler breeders was obtained. The variant-specific RT-PCR analysis showed that 4/91, Massachusetts, QX, Italy-02 and D274 strains were present in commercial flocks in eastern Spain, being 4/91 the most prevalent in all the productive orientations. In layers 100% of QX prevalence, 14% of Italy 02 and 14% of D274 was detected. Regarding broilers, a prevalence of 18% of Massachusetts strain was also detected. In contrast, in broiler breeders´ farms only 4/91 strain was found. In conclusion, our findings showed the presence of IBV in eastern Spain and the changing situation of the IBV variants´ prevalence, being different according to the productive orientation. The continuous emergence of new variants emphasizes the importance of continuous IBV monitoring in order to optimize vaccination strategies.


Subject(s)
Coronavirus Infections , Infectious bronchitis virus , Poultry Diseases , Animals , Chickens , Coronavirus Infections/epidemiology , Coronavirus Infections/veterinary , Female , Poultry Diseases/epidemiology , Prevalence , Seroepidemiologic Studies , Spain/epidemiology
10.
Viruses ; 14(4)2022 03 30.
Article in English | MEDLINE | ID: covidwho-1810314

ABSTRACT

The chicken astrovirus (CAstV) is a ubiquitous enteric RNA virus that has been associated mainly with conditions, such as the runting-stunting syndrome, severe kidney disease, visceral gout, and white chick syndrome, in broiler-type chickens worldwide. Sequence analysis of the capsid genes' amino acids of the strains involved in these conditions reveals a genetic relationship and diversity between and within the CAstV genogroups and subgroups based on phylogenetic analysis, genetic distance (p-dist), and pathogenicity. While the two genogroups (A and B) are demarcated phylogenetically, their pairwise amino acid sequence identity is 39% to 42% at a p-dist of 0.59 to 0.62. Group-A consists of three subgroups (Ai, Aii, and Aiii) with an inter- and intra-subgroup amino acid identity of 78% to 82% and 92% to 100%, respectively, and a p-dist of 0.18 to 0.22. On the other hand, the six subgroups (Bi, Bii, Biii, Biv, Bv, and Bvi) in Group-B, with a p-dist of 0.07 to 0.18, have an inter- and intra-subgroup amino acid identity of 82% to 93% and 93% to 100%, respectively. However, these groupings have little to no effect on determining the type of CAstV-associated pathology in chickens.


Subject(s)
Astroviridae Infections , Avastrovirus , Poultry Diseases , Amino Acids/genetics , Animals , Astroviridae Infections/veterinary , Chickens , Phylogeny
11.
Viruses ; 14(4)2022 03 29.
Article in English | MEDLINE | ID: covidwho-1810312

ABSTRACT

The complete nucleotide sequence of the S1 glycoprotein gene of the Japanese infectious bronchitis virus (IBV) strains was determined and genetically analyzed. A total of 61 Japanese IBV strains were classified into seven genotypes, namely GI-1, 3, 7, 13, 18, 19, and GVI-1 using the classification scheme that was proposed by Valastro et al, with three exceptions. These genotypes practically corresponded to those defined in Japan, namely Mass, Gray, JP-II, 4/91, JP-I, JP-III, and JP-IV, which have been identified through their partial nucleotide sequences containing hypervariable regions 1 and 2. In addition, three exceptive strains were considered to be derived from recombination within the S1 gene of IBV strains G1-13 and GI-19. By analyzing the amino acid polymorphism of the S1 glycoprotein among Japanese genotypes, a diversity was observed based on the genotype-specific amino acid residue, the proteolytic cleavage motif at the S1/S2 cleavage site, and the position of the potential N-glycosylation sites.


Subject(s)
Coronavirus Infections , Infectious bronchitis virus , Poultry Diseases , Amino Acids/genetics , Animals , Chickens , Coronavirus Infections/veterinary , Glycoproteins/genetics , Infectious bronchitis virus/genetics , Japan , Phylogeny
12.
Viruses ; 14(4)2022 03 25.
Article in English | MEDLINE | ID: covidwho-1798882

ABSTRACT

Metapneumoviruses, members of the family Pneumoviridae, have been identified in birds (avian metapneumoviruses; AMPV's) and humans (human metapneumoviruses; HMPV's). AMPV and HMPV are closely related viruses with a similar genomic organization and cause respiratory tract illnesses in birds and humans, respectively. AMPV can be classified into four subgroups, A-D, and is the etiological agent of turkey rhinotracheitis and swollen head syndrome in chickens. Epidemiological studies have indicated that AMPV also circulates in wild bird species which may act as reservoir hosts for novel subtypes. HMPV was first discovered in 2001, but retrospective studies have shown that HMPV has been circulating in humans for at least 50 years. AMPV subgroup C is more closely related to HMPV than to any other AMPV subgroup, suggesting that HMPV has evolved from AMPV-C following zoonotic transfer. In this review, we present a historical perspective on the discovery of metapneumoviruses and discuss the host tropism, pathogenicity, and molecular characteristics of the different AMPV and HMPV subgroups to provide increased focus on the necessity to better understand the evolutionary pathways through which HMPV emerged as a seasonal endemic human respiratory virus.


Subject(s)
Metapneumovirus , Paramyxoviridae Infections , Poultry Diseases , Animals , Chickens , Humans , Metapneumovirus/genetics , Paramyxoviridae Infections/epidemiology , Paramyxoviridae Infections/veterinary , Poultry Diseases/epidemiology , Retrospective Studies
13.
Viruses ; 14(5)2022 04 20.
Article in English | MEDLINE | ID: covidwho-1792406

ABSTRACT

Infectious bronchitis virus (IBV) is an avian coronavirus that causes respiratory disease but can affect the reproductive tract of laying-type chickens. If infection occurs in pullets, false layer syndrome, which is characterized by the development of large, fluid-filled cystic oviducts, can occur. Recently, IBV strain DMV/1639 has been detected in parts of Canada and the U.S., where false layer syndrome has occurred, though it is not clear if IBV is the sole cause or if age at infection is an influencing variable. Our study investigates the role and timing of IBV infection on the development of false layer syndrome, using the IBV types DMV/1639 and Massachusetts (Mass). Six groups of 120 SPF chickens were challenged at either three, seven, or fourteen days of age, using either DMV/1639 or Mass IBV. Cystic oviducts were seen in all the challenged groups, and the pullets challenged at 14 days of age had fewer cystic oviducts than pullets challenged at 3 or 7 days of age. The highest percentage of severe histology lesion scores were seen in the 3-day challenge groups. The data collected in this experiment confirm that IBV DMV/1639 causes cystic oviducts and indicate that age at infection plays a role in the pathogenesis of false layer syndrome.


Subject(s)
Coronavirus Infections , Infectious bronchitis virus , Oviducts , Poultry Diseases , Animals , Chickens , Coronavirus Infections/epidemiology , Coronavirus Infections/veterinary , Female , Incidence , Infectious bronchitis virus/isolation & purification , Oviducts/pathology , Poultry Diseases/epidemiology , Poultry Diseases/virology
14.
BMC Vet Res ; 18(1): 90, 2022 Mar 07.
Article in English | MEDLINE | ID: covidwho-1789121

ABSTRACT

BACKGROUND: Infectious bronchitis virus (IBV) leads to huge economic losses in the poultry industry worldwide. The high levels of mutations of IBV render vaccines partially protective. Therefore, it is urgent to explore an effective antiviral drug or agent. The present study aimed to investigate the in vivo anti-IBV activity of a mixture of plant essential oils (PEO) of cinnamaldehyde (CA) and glycerol monolaurate (GML), designated as Jin-Jing-Zi. RESULTS: The antiviral effects were evaluated by clinical signs, viral loads, immune organ indices, antibody levels, and cytokine levels. The infection rates in the PEO-M (middle dose) and PEO-H (high dose) groups were significantly lower than those in the prevention, positive drug, and PEO-L (low dose) groups. The cure rates in the PEO-M and PEO-H groups were significantly higher than those in the prevention, positive drug, and PEO-L groups, and the PEO-M group had the highest cure rate of 92.31%. The symptom scores and IBV mRNA expression levels were significantly reduced in the PEO-M group. PEO significantly improved the immune organ indices and IBV-specific antibody titers of infected chickens. The anti-inflammatory factor levels of IL-4 and IFN-γ in the PEO-M group maintained high concentrations for a long time. The IL-6 levels in the PEO-M group were lower than those in prevention, positive drug, and PEO-L groups. CONCLUSION: The PEO had remarkable inhibition against IBV and the PEO acts by inhibiting virus multiplication and promoting immune function, suggesting that the PEO has great potential as a novel anti-IBV agent for inhibiting IBV infection.


Subject(s)
Coronavirus Infections , Infectious bronchitis virus , Oils, Volatile , Poultry Diseases , Viral Vaccines , Animals , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Chickens , Coronavirus Infections/drug therapy , Coronavirus Infections/prevention & control , Coronavirus Infections/veterinary , Oils, Volatile/pharmacology , Oils, Volatile/therapeutic use , Plant Oils/pharmacology , Plant Oils/therapeutic use , Poultry Diseases/drug therapy , Poultry Diseases/prevention & control , Viral Vaccines/therapeutic use
15.
J Virol ; 96(6): e0205921, 2022 03 23.
Article in English | MEDLINE | ID: covidwho-1788916

ABSTRACT

The Gammacoronavirus infectious bronchitis virus (IBV) is a highly contagious global pathogen prevalent in all types of poultry flocks. IBV is responsible for economic losses and welfare issues in domestic poultry, resulting in a significant risk to food security. IBV vaccines are currently generated by serial passage of virulent IBV field isolates through embryonated hens' eggs. The different patterns of genomic variation accumulated during this process means that the exact mechanism of attenuation is unknown and presents a risk of reversion to virulence. Additionally, the passaging process adapts the virus to replicate in chicken embryos, increasing embryo lethality. Vaccines produced in this manner are therefore unsuitable for in ovo application. We have developed a reverse genetics system, based on the pathogenic IBV strain M41, to identify genes which can be targeted for rational attenuation. During the development of this reverse genetics system, we identified four amino acids, located in nonstructural proteins (nsps) 10, 14, 15, and 16, which resulted in attenuation both in vivo and in ovo. Further investigation highlighted a role of amino acid changes, Pro85Leu in nsp 10 and Val393Leu in nsp 14, in the attenuated in vivo phenotype observed. This study provides evidence that mutations in nsps offer a promising mechanism for the development of rationally attenuated live vaccines against IBV, which have the potential for in ovo application. IMPORTANCE The Gammacoronavirus infectious bronchitis virus (IBV) is the etiological agent of infectious bronchitis, an acute, highly contagious, economically important disease of poultry. Vaccination is achieved using a mixture of live attenuated vaccines for young chicks and inactivated vaccines as boosters for laying hens. Live attenuated vaccines are generated through serial passage in embryonated hens' eggs, an empirical process which achieves attenuation but retains immunogenicity. However, these vaccines have a risk of reversion to virulence, and they are lethal to the embryo. In this study, we identified amino acids in the replicase gene which attenuated IBV strain M41, both in vivo and in ovo. Stability assays indicate that the attenuating amino acids are stable and unlikely to revert. The data in this study provide evidence that specific modifications in the replicase gene offer a promising direction for IBV live attenuated vaccine development, with the potential for in ovo application.


Subject(s)
Amino Acids , Coronavirus Infections , Infectious bronchitis virus , Poultry Diseases , Viral Nonstructural Proteins , Viral Vaccines , Amino Acids/chemistry , Amino Acids/genetics , Animals , Chick Embryo , Chickens , Coronavirus Infections/prevention & control , Coronavirus Infections/veterinary , Coronavirus Infections/virology , Female , Infectious bronchitis virus/genetics , Poultry Diseases/prevention & control , Poultry Diseases/virology , Vaccines, Attenuated/genetics , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/genetics , Viral Vaccines/genetics
16.
Virol J ; 19(1): 62, 2022 04 07.
Article in English | MEDLINE | ID: covidwho-1785161

ABSTRACT

BACKGROUND: The QX-type infectious bronchitis virus (IBV) has become the predominant genotype worldwide in recent years and has caused serious economic losses to the chicken industry. The most significant feature of QX IBV is that its infection in the early growing stage can cause abnormal oviduct development, resulting in a high proportion of 'false layers' in poultry flocks of laying hens and breeders. However, few studies have evaluated whether infections of QX-type IBV in laying stages can also cause severe pathological changes in the oviduct. METHODS: In this study, 300-day-old specific-pathogen-free chickens were infected either with the QX-type strain QXL or Massachusetts (Mass)-type strain M41 to compare their pathogenicity on different segments of the oviduct. RESULTS: Both the QXL and M41 strains successfully replicated in all segments of the oviduct; however, the QXL strain was more highly distributed in mucosal layer and caused severe lesions in the lamina propria, including interstitial dilation, inflammatory cell infiltration, and distinct expansion of tubular glands. Moreover, the QXL strain induced high expression of proinflammatory cytokines and cytotoxic molecules in the majority of segments in the oviduct. Further research found that the QXL strain may affected the formation of shell membranes and eggshells by inhibiting the expression of type I collagen and CaBP-D28k. CONCLUSIONS: Our results indicate that the QX-type IBV is more pathogenic than Mass-type IBV to oviduct in laying phase. Collectively, these findings provide detailed information on the pathological changes in different segments of the oviduct in laying phase, which could offer a better understanding about the pathogenicity of IBV.


Subject(s)
Coronavirus Infections , Infectious bronchitis virus , Poultry Diseases , Animals , Chickens , Female , Humans , Infectious bronchitis virus/genetics , Oviducts/pathology , Virulence
17.
Trop Anim Health Prod ; 54(2): 117, 2022 Feb 27.
Article in English | MEDLINE | ID: covidwho-1767581

ABSTRACT

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


Subject(s)
Influenza A Virus, H9N2 Subtype , Influenza in Birds , Poultry Diseases , Animals , Chickens , Cross-Sectional Studies , Farms , Financial Stress , Influenza in Birds/epidemiology , Iran/epidemiology
18.
Virus Genes ; 58(3): 203-213, 2022 Jun.
Article in English | MEDLINE | ID: covidwho-1766911

ABSTRACT

Infectious bronchitis virus (IBV) and avian influenza virus (AIV) are two major respiratory infections in chickens. The coinfection of these viruses can cause significant financial losses and severe complications in the poultry industry across the world. To examine transcriptome profile changes during the early stages of infection, differential transcriptional profiles in tracheal tissue of three infected groups (i.e., IBV, AIV, and coinfected) were compared with the control group. Specific-pathogen-free chickens were challenged with Iranian variant-2-like IBV (IS/1494), UT-Barin isolates of H9N2 (A/chicken/Mashhad/UT-Barin/2017), and IBV-AIV coinfection; then, RNA was extracted from tracheal tissue. The Illumina RNA-sequencing (RNA-seq) technique was employed to investigate changes in the Transcriptome. Up- and downregulated differentially expressed genes (DEGs) were detected in the trachea transcriptome of all groups. The Kyoto Encyclopedia of Genes and Genomes pathway and Gene Ontology databases were examined to identify possible relationships between DEGs. In the experimental groups, upregulated genes were higher compared to downregulated genes. A more severe immune response was observed in the coinfected group; further, cytokine-cytokine receptor interaction, RIG-I-like receptor signaling, Toll-like receptor signaling, NOD-like receptor signaling, Janus kinase/signal transducer, and activator of transcription, and apoptotic pathways were important upregulated genes in this group. The findings of this paper may give a better understanding of transcriptome changes in the trachea during the early stages of infection with these viruses.


Subject(s)
Bronchitis , Coinfection , Coronavirus Infections , Infectious bronchitis virus , Influenza A Virus, H9N2 Subtype , Influenza in Birds , Poultry Diseases , Animals , Bronchitis/genetics , Bronchitis/veterinary , Chickens , Gene Expression Profiling , Infectious bronchitis virus/genetics , Influenza A Virus, H9N2 Subtype/genetics , Influenza in Birds/genetics , Iran , Poultry Diseases/genetics , RNA , Trachea , Transcriptome/genetics
19.
Viruses ; 14(3)2022 03 08.
Article in English | MEDLINE | ID: covidwho-1765950

ABSTRACT

Within-host viral diversity offers a view into the early stages of viral evolution occurring after a virus infects a host. In recent years, advances in deep sequencing have allowed for routine identification of low-frequency variants, which are important sources of viral genetic diversity and can potentially emerge as a major virus population under certain conditions. We examined within-host viral diversity in turkeys and chickens experimentally infected with closely related H7N3 avian influenza viruses (AIVs), specifically one high pathogenicity AIV (HPAIV) and two low pathogenicity AIV (LPAIVs) with different neuraminidase protein stalk lengths. Consistent with the high mutation rates of AIVs, an abundance of intra-host single nucleotide variants (iSNVs) at low frequencies of 2-10% was observed in all samples collected. Furthermore, a small number of common iSNVs were observed between turkeys and chickens, and between directly inoculated and contact-exposed birds. Notably, the LPAIVs have significantly higher iSNV diversities and frequencies of nonsynonymous changes than the HPAIV in both turkeys and chickens. These findings highlight the dynamics of AIV populations within hosts and the potential impact of genetic changes, including mutations in the hemagglutinin gene that confers the high pathogenicity pathotype, on AIV virus populations and evolution.


Subject(s)
Influenza in Birds , Poultry Diseases , Animals , Chickens , Genetic Variation , Influenza A Virus, H7N3 Subtype/genetics , Turkeys , Virulence/genetics
20.
Avian Pathol ; 51(2): 107-112, 2022 Apr.
Article in English | MEDLINE | ID: covidwho-1706620

ABSTRACT

The threat posed by zoonotic diseases and other livestock pathogens has never been greater, and thus we must do all we can to learn from experience in order to tackle emerging disease threats. The process of developing a new veterinary vaccine involves the generation of a specific set of data in order to meet the strict product licencing requirements of regulatory approval bodies around the globe. As a result, it is important that those embarking on the development of a vaccine using either conventional or novel platform technologies understand these regulations. In addition, there are a number of specific requirements that one needs to take into consideration when developing a product specifically for the commercial poultry market. This paper briefly outlines the veterinary vaccine development process in general and then explores how this process can be accelerated. It also recognizes the "One Health" lessons that can be learnt from the recent rapid development of vaccines to tackle the COVID-19 pandemic and acknowledges the important measures that regulatory authorities have taken in the creation of an environment to facilitate the licencing of new vaccine platform technologies.


Subject(s)
COVID-19 , Poultry Diseases , Vaccines , Animals , COVID-19/prevention & control , COVID-19/veterinary , Pandemics , Technology
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