Insights into antiviral activity of chlorpromazine against RNA viruses: Molecular docking, ADME profile, and semi-in vivo study.

This study aimed at determining the possible exposure of wild birds to avian influenza (AI), infectious bronchitis (IB) and Newcastle disease (ND) viruses. Apparently healthy species of free flying wild birds were captured using locally-made baited traps set at strategic watering and feeding locations and in poultry farms. Few species of captive wild birds in households and live bird markets (LBMs) were also sampled. Sera from blood samples collected were analyzed for antibodies to AI, IB and ND viruses using enzyme linked immunorsorbent assay (ELISA). Out of the 209 sera analysed, Bubulcus ibis was 24%, 70% and 27% while Psittacus erithacus was 7%, 21% and 7% positive for antibodies to AI, IB and ND viruses, respectively. Branta canadensis , was 35% and 64% positive for antibodies to AI and IB viruses. Balearica regulorum and Numidia maleagris were 100% and 9% positive to AI virus antibodies. Free flying birds were 19 (15%), 57 (45%) and 27 (21%) positive while captive wild birds were 11%, 20% and 14% positive to AI, IB and ND viruses antibodies, respectively. The results of this study confirm that wild birds were exposed to AI, IB and ND viruses. There was co-exposure of some wild bird species to AI, IB and ND viruses. These birds could possibly serve as carriers and disseminators of AI, IB and ND to poultry. Therefore, control measures against these important poultry diseases should include incursion of wild birds. Keywords: Avian influenza, Infectious bronchitis, Newcastle disease, Nigeria, Wild birds

Thematic Minireview Series: Toward a Structural Basis for Understanding Influenza Virus-Host Cell Interactions

A duplex RT-PCR assay for detection of H9 subtype avian influenza viruses and infectious bronchitis viruses

A total of 166 infectious bronchitis virus (IBV) hemagglutination (HA) antigen preparations were made during a 30-month period from allanto-amnionic fluid (AAF) from chicken embryos inoculated with 10 different IBV strains (Mass 41, Conn 46, H52, Florida 18288, Ark 99, JMK, T, Holte, EF, SE17). Antigens were prepared by inoculating 9- or 10-day-old embryos with 10(5.0) to 10(6.5) EID50 IBV, harvesting AAF after a 30-hour-postinoculation incubation, and phospholipase C (PLC) treatment of virus concentrated by pelleting from the AAF. Longer (48 hr) incubation times were tried, but production of H52 HA antigen was successful only from AAF harvested after 30 hours of incubation. AAF from JMK-infected embryos had lower infectivity titers and frequently yielded lower HA antigen titers than the other strains. The treatment of AAF with fluorocarbon did not enhance or diminish HA activity but did yield clearer antigens by removing extraneous material. Polyethylene glycol precipitation of virus was an acceptable alternative to pelleting virus at 39,000 X g. Inactivation of IBV with 0.1% betapropiolactone did not affect HA activity, whereas inactivation with 0.1% formalin caused a marked reduction in HA titer. Different buffer formulations including phosphate, tris, or HEPES were tried to optimize the conditions for PLC treatment of virus concentrate, but there were no apparent differences in the antigens prepared in the different buffers. The HA antigen preparations were stored and were stable at 4 C. Antigen titers of greater than or equal to 64 after storage for 20 months or longer were not uncommon. Addition of merthiolate as a preservative had no deleterious effect on HA activity. Antigen stability appeared to be enhanced by incorporating EDTA in buffer for virus pellet recovery and during enzyme treatment. Attempts to produce HA antigens from cell-culture-adapted virus propagated in chicken kidney cells were less satisfactory. An acceptable HA antigen was prepared from only two (Mass 41, SE17) of the seven strains that were tried. Virus propagation in chicken embryos is the better method of the two for IBV HA antigen production. Aside from the need to concentrate virus and treat the concentrate with PLC, there appeared to be considerable latitude in the procedures that can be used to make acceptable IBV HA antigens.

For decades, infectious bronchitis (IB), caused by the infectious bronchitis virus (IBV), has posed a significant threat to poultry health and is mainly controlled by vaccines. However, the currently available commercial vaccines do not provide adequate protection against new IBV strains that emerge due to ongoing evolution. Therefore, new antiviral strategies need to be explored. Cepharanthine (CEP), tetrandrine (TET), and berbamine hydrochloride (BBM) are natural plant-derived bis-benzylisoquinoline alkaloids (BBAs) with proven antiviral activities against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), porcine epidemic diarrhea virus (PEDV), and other viruses. Despite this, their potential antiviral activities against IBV remain unknown. As a proof-of-concept study, we aimed to investigate the inhibitory effects of CEP, TET, and BBM on the laboratory-adapted IBV Beaudette strain in Vero cells and of CEP in chicken embryos. Our research demonstrated that CEP, TET, and BBM effectively suppressed IBV infection in Vero cells, with CEP showing a particularly high selective index of 309.6. These compounds dose-dependently decreased IBV RNA levels and N protein expression and lowered intracellular and extracellular viral titers. Notably, CEP also exhibited antiviral activity against IBV infection in chicken embryos, resulting in reduced mortality and fewer lesions. While these findings highlight the potential of CEP, TET, and BBM as candidates for further development, further studies are required to evaluate their efficacy against field-prevalent IBV strains (e.g., Massachusetts, QX-like) and clarify the specific antiviral mechanisms.

Viral interference between H9N2-low pathogenic avian influenza virus and avian infectious bronchitis virus vaccine strain H120 in vivo

Background: Poultry industries play an important role in the human food supply. Newcastle disease virus (NDV), Infectious bronchitis virus (IBV), and Avian influenza virus (AIV) can cause epizootic outbreaks in poultry industries and lead to extensive economic losses. Furthermore, these viruses can also infect wild birds, and avian influenza virus is a serious threat to humans. Here, a multiepitope vaccine has been designed to induce an immune response against IBV, NDV, and AIV using extensive bioinformatics tools. Methods: To do so, the antigenic proteins, including the hemagglutinin of H5 and H7 subtypes of AIV, nucleocapsid and spike proteins of IBV, and fusion and hemagglutinin-neuraminidase proteins of NDV, have been studied to find immunodominant epitopes with MHC-I/MHC-II binding potential. Four antigenic and non-allergenic epitopes from each antigenic protein were connected to avian beta-defensin 1 as an adjuvant to construct the multiepitope vaccine. To investigate the potential of vaccine-induced activation of toll-like receptors (TLR-2, 5), the tertiary structure of the vaccine was modeled and docked to TLR-2/5 proteins. Results: Evaluation of the physicochemical properties of the vaccine construct has demonstrated the stability and solubility of the vaccine upon overexpression. The vaccine construct demonstrated antigenicity and was specified as a non-allergenic protein. The vaccine can induce significant cellular and humoral immune responses, and TLR proteins can recognize the vaccine in its three-dimensional form. Conclusion: Overall, the multiepitope vaccine designed in the present study against IBV, NDV, and AIV shows significant immunological potential that should be further investigated in wet laboratory experiments.

A flock of 54 wk-old layer birds exhibiting signs of respiratory distress, greenish diarrhea, and drop in egg production was investigated. A marked drop in egg production (55%) was recorded with eggs appearing white and soft-shelled. Mortality was in the range of 1%–2% with post-mortem lesions revealing cloudy air sacs, frothy, and congested lungs. Viral RNA was extracted from pooled tissue samples (trachea, lungs, spleen, and liver) and tested for Avian influenza virus (AIV), Newcastle disease virus (NDV), and infectious bronchitis virus (IBV) by reverse transcriptase-polymerase chain reaction (RT-PCR). In addition, virus isolation was attempted in 9–11 day-old embryonating chicken eggs (ECE). In order to determine the prevalence of IBV serotype(s) in the flock, serum samples were screened by hemagglutination-inhibition (HI) test using IBV antigens and antisera (Arkansas, Connecticut, and Massachusetts). Neither AIV nor NDV but IBV was detected in the tissue samples by RT-PCR. In addition, virus isolate obtained after four serial passages in ECE produced dwarfed, stunted, and hemorrhagic embryos, and the isolate was confirmed by RT-PCR to be IBV. The serum samples were 100% seropositive for three serotypes with HI titres ranging from 5 to 12 Log2. In this study, IBV was confirmed as the causative agent of the observed respiratory distress and drop in egg production. Also, the evidence of co-circulation of multiple IBV serotypes was established, this to the best of our knowledge is the first of such report in Nigeria. We recommend extensive molecular and sero-epidemiology of circulating IBV genotypes and serotypes in Nigeria with the aim of developing better control strategies, including vaccination.

Viral Tropism and the Pathogenesis of Influenza in the Mammalian Host

The coronavirus, known to exist in humans and livestock for an extended period, includes variants such as the infectious bronchitis (IB) virus in chickens. As a single-stranded RNA virus, coronaviruses are prone to mutations. Patikan Kebo (Euphorbia hirta L) is a medicinal herb containing various compounds like Flavonoids, Mirisil, Alkaloids, Laraserol, Hentriakontanol, and Komositin, known for their antibacterial, antiviral, and anti-worm properties. This study aimed to evaluate the toxicity of Patikan Kebo extract on Chicken Embryo Eggs (TAB) and assess its antiviral potential against the chicken AI coronavirus. The experimental approach involved three concentrations of Patikan Kebo extract (0.01% - P1, 0.1% - P2, 1% - P3), a control group without Patikan Kebo extract (K+), and a control group without the virus (K-). Data analysis was conducted using ANOVA and Tukey HSD in the SPSS program. The results from ANOVA indicated that the dose of Patikan Kebo significantly impacted (P<0.05) its antiviral activity against the IB virus. The average HA Titer 2 (Log2) demonstrated a 47% reduction in viral activity. In conclusion, the most effective herbal antiviral dose against the IB virus was determined to be 0.1% Patikan Kebo extract.

Viral outbreaks are a common cause of morbidity and mortality in livestock and human populations. Lack of good vaccines and poor control measures along with natural viral genetic drifting and shifting are the common causes of new viral strains and outbreaks. The current study reports the synthesis of some 2-aryl substituted thiazolidine-4-carboxylic acids 1a-h and their 3-acetyl 2a and 3-benzoyl derivatives 3a. Two important poultry viruses: Avian influenza virus (AIV; A/Chicken/Italy/1994/H9N2) and infectious bronchitis virus (IBV) were selected, grown in ‎9-11 days old chicken embryonated eggs‎, and subjected to in ovo anti-viral assays. Most of the synthesized compounds were found active against AIV subtype H9N2 and IBV. In the case of AIV, the best results were attained for compound 1d which showed an IC50 value of 3.47 µM, while IBV 1c showed IC50 value of 4.10 µM. The lower IC50 values of these compounds correlate with the high potency of these compounds, especially in comparison with control groups. The standard drugs amantadine and ribavarin were used as positive controls in the case of AIV and IBV, respectively. Better results were obtained with 2-aryl substituted thiazolidine-4-carboxylic acids 1a-h compared to their N-acylated derivatives 2a and 3a against both viruses. In conclusion, this preliminary data support the idea that thiazolidine carboxylic acids could be used as anti-viral drugs against AIV and IBV infections.

The first H5N1 outbreak in Burkina Faso was reported to the World Organization for Animal Health on 3 April 2006. This study aimed to determine the prevalence of avian influenza virus, infectious bronchitis virus, and Newcastle disease virus among domestic and wild birds in highly pathogenic avian influenza (HPAI) H5N1 outbreaks areas. We collected paired tracheal and cloacal swabs from 283 birds including 278 domestic and five wild birds (three vultures, one sparrowhawk and one Western Grey Plantain-eater) in the Central Region (Ouagadougou) and the Western Region (Bobo-Dioulasso and Sokoroni) of Burkina Faso. Total RNA extracted from samples were subjected to reverse transcription and resulting cDNA amplified by PCR using specific primers for detection of Avian Influenza Virus (AIV mainly highly pathogenic H5N1), Infectious Bronchitis Virus (IBV), and Newcastle Disease Virus (NDV) for the first time in Burkina Faso. Our results show that 13.8% (39/283) samples were reactive for NDV, and the prevalence of IBV was 3.9% (11/283). None of the 283 birds were co-infected by AIV, IBV and/or NDV in our study areas. The prevalence of influenza A virus was 3.2% (95% CI: 0-6.6) with a 1.7% (95% CI: 0-3.2) prevalence of H5N1 being detected. Positive cases of H5N1 virus were found in two out of three vultures in Ouagadougou, and in three out of 203 local chickens in the Western Region. These results confirm the presence of influenza A H5N1 virus, IBV and NDV in domestic and wild birds in Burkina Faso.

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

Antiviral effect of the viroporin inhibitors against Taiwan isolates of infectious bronchitis virus (IBV)

Myricetin exerts its antiviral activity against infectious bronchitis virus by inhibiting the deubiquitinating activity of papain-like protease