scholarly journals Characterization of Co-infection With Fowl Adenovirus Serotype 4 and 8a

2021 ◽  
Vol 12 ◽  
Author(s):  
Jingyi Liu ◽  
Xinjin Shi ◽  
Lu Lv ◽  
Kai Wang ◽  
Zhiwei Yang ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Economic Losses ◽  
Tunel Staining ◽  
Specific Pathogen Free ◽  
Infection Group ◽  
Viral Loads ◽  
Specific Pathogen ◽  
Fowl Adenovirus Serotype 4

Fowl adenoviruses (FAdVs), which are distributed worldwide, have caused considerable economic losses to poultry farms. Co-infection with FAdVs and other avian pathogens has been reported previously. However, the pathogenicity of different serotypes of FAdVs causing co-infection remains unclear. Herein, strain HN from FAdV species C serotype 4 (FAdV-4) and strain AH720 from species E serotype 8a (FAdV-8a) were used to assess the pathogenicity of their co-infection in specific-pathogen-free (SPF) chickens. Compared with chickens infected with FAdV-4 alone, those co-infected with FAdV-4 and FAdV-8a showed similar clinical symptoms, mortality rates and degree of tissue lesions, and notably decreased viral loads of HN. Conversely, the viral loads of AH720 increased markedly in the co-infection group compared with that in chickens infected with AH720 strain alone. Increased viral loads of AH720 in the liver were suspected to contribute to the pathogenicity of chickens co-infected with the HN and AH720 strains. This was further investigated by histopathology and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining analyses. Collectively, these data indicated that co-infection with FAdV-4 and FAdV-8a suppresses the replication and proliferation of FAdV-4 but enhances the replication and proliferation of FAdV-8a in chicken liver. This study will provide valuable information for the further investigation of the interactions between FAdV-4 and FAdV-8a during co-infection.

scholarly journals Genetic and Antigenic Characterization of Avian Avulavirus Type 6 (AAvV-6) Circulating in Canadian Wild Birds (2005–2017)

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 543
Author(s):  
Tamiko Hisanaga ◽  
Catherine Soos ◽  
Nicola Lewis ◽  
Oliver Lung ◽  
Matthew Suderman ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Fusion Gene ◽  
Full Genome ◽  
Genome Sequences ◽  
Viral Shedding ◽  
Genetic Groups ◽  
Antigenic Characterization ◽  
Specific Pathogen ◽  
First Time

We describe for the first time the genetic and antigenic characterization of 18 avian avulavirus type-6 viruses (AAvV-6) that were isolated from wild waterfowl in the Americas over the span of 12 years. Only one of the AAvV-6 viruses isolated failed to hemagglutinate chicken red blood cells. We were able to obtain full genome sequences of 16 and 2 fusion gene sequences from the remaining 2 isolates. This is more than double the number of full genome sequences available at the NCBI database. These AAvV-6 viruses phylogenetically grouped into the 2 existing AAvV-6 genotype subgroups indicating the existence of an intercontinental epidemiological link with other AAvV-6 viruses isolated from migratory waterfowl from different Eurasian countries. Antigenic maps made using HI assay data for these isolates showed that the two genetic groups were also antigenically distinct. An isolate representing each genotype was inoculated in specific pathogen free (SPF) chickens, however, no clinical symptoms were observed. A duplex fusion gene based real-time assay for the detection and genotyping of AAvV-6 to genotype 1 and 2 was developed. Using the developed assay, the viral shedding pattern in the infected chickens was examined. The chickens infected with both genotypes were able to shed the virus orally for about a week, however, no significant cloacal shedding was detected in chickens of both groups. Chickens in both groups developed detectable levels of anti-hemagglutinin antibodies 7 days after infection.

scholarly journals Pathogenicity of Mycoplasma synoviae in Broiler Chickens

1998 ◽  
Vol 35 (3) ◽  
pp. 178-190 ◽  
Author(s):  
S. B. Lockaby ◽  
F. J. Hoerr ◽  
L. H. Lauerman ◽  
S. H. Kleven
Keyword(s):  
Broiler Chickens ◽  
Specific Pathogen Free ◽  
Skeletal System ◽  
Chain Reaction ◽  
Lesion Development ◽  
Mycoplasma Synoviae ◽  
Specific Pathogen ◽  
Upper Respiratory ◽  
Polymerase Chain

Six isolates of Mycoplasma synoviae, identified as WVU 1853, K1968, K1858, 92D8034, F10–2AS, and FMT, were compared for pathogenicity in broiler chickens. Specific-pathogen-free chickens were inoculated, in two groups of 20, with each isolate by footpad or eyedrop inoculation at 1 day of age and were examined at necropsy 7, 14, 28, and 42 days postinoculation. Specimens were taken for histopathology, culture, polymerase chain reaction assay, and hemagglutination-inhibition serology. Isolates were grouped according to pathogenicity on the basis of differences in lesion development and tissue distribution in the respiratory system, other viscera, and the skeletal system. K1968 (pathogenic) induced lesions in all sites examined in both the footpad and eyedrop inoculation groups. It was detected in all sites following footpad inoculation and in all sites except viscera following eyedrop inoculation. WVU 1853, K1858, and 92D8034 (moderately pathogenic) induced lesions and were detected in all sites following footpad inoculation. With eyedrop inoculation, lesions were identified only in upper and lower respiratory sites, and organisms were detected only in upper respiratory sites. F10–2AS (moderately pathogenic) was similar; however, footpad inoculation failed to induce visceral lesions or permit organism detection in any site. F10–2AS was detected in upper and lower respiratory tissues following eyedrop inoculation. FMT (mildly pathogenic) induced only upper respiratory lesions when either footpad or eyedrop inoculation was used, and detection was restricted to upper respiratory sites following eyedrop inoculation. These results are useful in comparative evaluations of the virulence of other M. synoviae isolates and form a basis for characterization of virulence factors of M. synoviae.

scholarly journals Characterization and pathogenicity of Vero cell-attenuated porcine epidemic diarrhea virus CT strain

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Yu Wu ◽  
Wei Li ◽  
Qingfeng Zhou ◽  
Qunhui Li ◽  
Zhichao Xu ◽  
...  
Keyword(s):  
Porcine Epidemic Diarrhea Virus ◽  
Clinical Symptoms ◽  
Vero Cells ◽  
Economic Losses ◽  
Protective Effects ◽  
Diarrhea Virus ◽  
Cytopathic Effects ◽  
Porcine Epidemic Diarrhea ◽  
Piglet Survival

Abstract Background Porcine epidemic diarrhea virus (PEDV) has caused enormous economic losses to the global pig industry. Currently available PEDV vaccine strains have limited protective effects against PEDV variant strains. Methods In this study, the highly virulent epidemic virus strain CT was serially passaged in Vero cells for up to 120 generations (P120). Characterization of the different passages revealed that compared with P10 and P64, P120 had a higher viral titer and more obvious cytopathic effects, thereby demonstrating better cell adaptability. Results Pathogenicity experiments using P120 in piglets revealed significant reductions in clinical symptoms, histopathological lesions, and intestinal PEDV antigen distribution; the piglet survival rate in the P120 group was 100%. Furthermore, whole-genome sequencing identified 13 amino acid changes in P120, which might be responsible for the attenuated virulence of P120. Conclusions Thus, an attenuated strain was obtained via cell passaging and that this strain could be used in preparing attenuated vaccines.

Pathologic Characterization of Genotypes XIV and XVII Newcastle Disease Viruses and Efficacy of Classical Vaccination on Specific Pathogen-Free Birds

2014 ◽  
Vol 52 (1) ◽  
pp. 120-131 ◽  
Author(s):  
L. Susta ◽  
M. E. B. Jones ◽  
G. Cattoli ◽  
S. Cardenas-Garcia ◽  
P. J. Miller ◽  
...  
Keyword(s):  
Newcastle Disease ◽  
Specific Pathogen Free ◽  
Specific Pathogen

Characterization Of The Lung Microbiome Of Specific Pathogen-Free Mice With And Without Exposure To Cigarette Smoke In Vivo

2011 ◽  
Author(s):  
Michael C. Shen ◽  
Angela M. Preston ◽  
Merritt G. Gillilland III ◽  
John R. Erb-Downward ◽  
Bradley Todd ◽  
...  
Keyword(s):  
Cigarette Smoke ◽  
Specific Pathogen Free ◽  
Lung Microbiome ◽  
Specific Pathogen

scholarly journals First Isolation and Molecular Characterization of Chicken Astrovirus and Avian Nephritis Virus in Chickens in Bangladesh

2021 ◽  
Vol 8 ◽  
Author(s):  
Md Zulfekar Ali ◽  
Mohammad Moktader Moula ◽  
Zafar Ahmed Bhuiyan ◽  
Md Giasuddin ◽  
Hyun-Jin Shin
Keyword(s):  
Phylogenetic Analysis ◽  
Molecular Characterization ◽  
Economic Damage ◽  
Specific Pathogen Free ◽  
Avian Nephritis Virus ◽  
Wide Range ◽  
Specific Pathogen ◽  
Reference Strains ◽  
Virus Screening

Chicken astrovirus (CAstV) and avian nephritis virus (ANV) are enteric viruses of poultry and have infected a wide range of poultry species worldwide, causing runting-stunting syndrome (RSS), which requires virus screening and results in serious economic damage. No confirmed cases have been reported from Bangladesh. In the present study, CAstV and ANV were monitored in Bangladesh. We monitored samples for CAstV and ANV and compared their genomic sequences to other reference strains. We found 8/31 flocks (25.8%) were positive for CAstV, 6/31 flocks (19.3%) had mixed infection of CAstV and ANV, and 1 flock (3.2%) was positive for ANV. Only ANV and a combination of CAstV and ANV were found in broilers and broiler breeders, but CAstV was found in all types of chickens. We isolated two of each from CAstV and ANV through specific pathogen-free chicken embryonated eggs via the yolk sac route. Phylogenetic analysis based on the ORF1b conserved region of CAstV and ANV suggested that the locally circulating strain was closely related to the strains isolated from India and Brazil. This report is the first molecular characterization of CAstV and ANV in Bangladesh. This study highlights that CAstV and ANV are circulating in Bangladeshi poultry.

scholarly journals Discrepancies in the efficacy of H5 inactivated avian influenza vaccines in specific-pathogen-free chickens against challenge with the Egyptian H5N8 clade 2.3.4.4 Group B virus isolated in 2018

2021 ◽  
pp. 2131-2141
Author(s):  
Amena Abd El-Moeid ◽  
Ayman Hany EL-Deeb ◽  
Marwa Fathy Elsaied ◽  
Reem Ahamed Soliman ◽  
Mounir Mohamed EL-Safty ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Histopathological Examination ◽  
Economic Losses ◽  
Specific Pathogen Free ◽  
Highly Pathogenic ◽  
Virus Shedding ◽  
Severity Scores ◽  
Specific Pathogen ◽  
Protection Efficacy ◽  
Sera Samples

Background and Aim: Highly pathogenic avian influenza H5N8 virus of clade 2.3.4.4 was newly emerged to Egypt and firstly detected in carcasses of wild birds in November 2016. This study assessed the protection efficacy and virus shedding reduction of three different inactivated avian influenza (AI) H5 (H5N1, H5N2, and H5N3) commercial vaccines against challenge with two newly emerging highly pathogenic AI virus H5N8 Egyptian isolates in specific-pathogen-free (SPF) chicks. Materials and Methods: 10-day-old SPF chicks (n=260) were divided into 20 groups (n=13). Groups 1-5 were vaccinated through the subcutaneous route (S/C) with 0.5 mL of H5N1 vaccine, Groups 6-10 were vaccinated (S/C) with 0.5 mL of H5N2 vaccine, and Groups 11-15 were vaccinated (S/C) with 0.5 mL of H5N3 vaccine. Positive control groups (16-19) were challenged at 25 and 31 days old (2 and 3 weeks post-vaccination [PV]) using H5N8 clade 2.3.4.4 A/duck/Egypt/ F13666A/2017(H5N8) and H5N8 clade 2.3.4.4 A/chicken/Egypt/18FL6/2018(H5N8). Group 20 was left non-vaccinated as a control. All vaccinated groups were divided and challenged with both viruses at 25 and 31 days of age. The viral challenge dose was 0.1 mL of 106 EID50/0.1 mL titer/chick, and it was administered oronasally. All chicks were kept in isolators for 14 days after each challenge. Sera samples were collected weekly and at 2 weeks post-challenge (PC) to detect a humoral immune response. PC mortalities were recorded daily for 10 days to calculate the protection percentages. Tracheal swabs were collected from the challenged chicks in different groups at 3, 5, 7, and 10 days PC. Kidneys and spleens were collected at 3, 5, 7, and 10 days PC and kept in formalin for histopathological examination to assess lesions and severity scores. Tracheal swabs were inoculated in 10-day-old SPF embryonated chicken eggs for virus titration and to calculate shedding levels. Results: All studied vaccines displayed 70-100% protection within 10 days PC. Hemagglutination inhibition results from sera samples revealed antibody titers ranging from 0.6 to 5.4 log2 starting at 1-week PV with the highest titers at 4 weeks PV. Challenged SPF chickens exhibited a notable reduction in virus shedding, with an average of 1.5-2 log10, compared to control birds. Various histopathological lesions with different scores were detected. Conclusion: Our findings suggest that the inadequate virus shedding reduction and protection efficacy of studied vaccines were variable and that the type of vaccine to be used under field conditions should be reconsidered. Study of the variability between the Egyptian old emerged AI (AIV) 2017 H5N8 strains and the new emerging AIV 2018 H5N8 is required to achieve optimal protection and limit the current economic losses.

scholarly journals Meclizine Inhibits Pseudorabies Virus Replication by Interfering With Virus Entry and Release

2021 ◽  
Vol 12 ◽  
Author(s):  
Panrao Liu ◽  
Danhe Hu ◽  
Lili Yuan ◽  
Zhengmin Lian ◽  
Xiaohui Yao ◽  
...  
Keyword(s):  
Viral Entry ◽  
Pseudorabies Virus ◽  
Molecular Mechanisms ◽  
Clinical Symptoms ◽  
Antiviral Effect ◽  
Inhibitory Effect ◽  
Economic Losses ◽  
Swine Industry ◽  
Viral Attachment ◽  
Viral Loads

Pseudorabies virus (PRV) is a pathogen that causes substantial economic losses to the swine industry. With the emergence and widespread of PRV variants since 2011 in China, current commercial vaccines cannot provide complete protection against PRV infection. Therefore, antiviral drugs may work as an alternative way to control and prevent PRV. In this study, the inhibitory effects and underlying molecular mechanisms of meclizine against PRV were studied. Meclizine displayed a significant inhibitory effect against PRV when it was added before, simultaneously with, or after virus infection. The inhibitory effect of meclizine occurred during viral entry and cell-to-cell spreading but not at viral attachment into PK-15 cells. Meclizine also inhibited viral particle release at the late stage of infection. The antiviral effect of meclizine was tested in mice, and the results showed that meclizine reduced the severity of clinical symptoms and the viral loads in tissues, and delayed the death, after PRV challenge. The above results indicated that meclizine had an inhibitory effect on PRV. Our findings will contribute to the development of potential therapeutic drugs against PRV infection.

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