Pub Date : 2023-08-01DOI: 10.1080/03079457.2023.2211548
Ibrahim Abd Elrahman Ghanem, Tamer Mahmoud Abdullatif, Ola Hassanin
Vaccines against vNDV are readily available and potentially protective; nevertheless, improved vaccination protocols are required to prevent clinical disease and discontinue the spread of the virus. This study assessed the effectiveness of two commercial recombinant herpesvirus of turkey vector vaccines (rHVT-NDV-IBDV) that express the fusion (F) protein of NDV and the virus protein 2 (VP2) of infectious bursal disease virus (IBDV). In commercial broilers with maternally-derived antibodies (MDAs) the efficacy of the rHVT-NDV-IBDV vaccines was evaluated when administered alone, in combination with live-attenuated NDV vaccine at one-day-old, or as part of a prime/boost strategy. The vaccinated birds were challenged with the genotype VIId vNDV strain (NDV/chicken/Egypt/1/2015) at various ages (14, 24 and 35 days). In comparison to sham-vaccinated control birds, the applied vaccination regimens were able to reduce or prevent mortality and virus shedding and clinical disease. Two weeks post-application, the two vector vaccines were serologically reactive with the MDAs and induced protective immune responses against the F protein. In the instance of early challenge at 14 days old, the combination of recombinant rHVT-NDV-IBDV with a live vaccine offered better protection and reduced virus shedding compared to the vector vaccine alone. Boosting with live NDV vaccine at 14 days old increased the protective effect of the vector vaccines and reduced virus shedding and the clinical index after challenge at 24 days old. Both combining and/or boosting with live vaccine together with the vector vaccine provided better protection and minimized virus shedding compared with vaccination with vector vaccine only in the instance of 5-week-old challenge.
{"title":"The protection conferred against virulent Newcastle disease virus (vNDV) genotype VII by commercial double recombinant HVT vaccines and NDV live-attenuated vaccine as prime/boost vaccination regimens in commercial broiler chickens carrying maternally-derived antibodies (MDAs) against NDV.","authors":"Ibrahim Abd Elrahman Ghanem, Tamer Mahmoud Abdullatif, Ola Hassanin","doi":"10.1080/03079457.2023.2211548","DOIUrl":"https://doi.org/10.1080/03079457.2023.2211548","url":null,"abstract":"<p><p>Vaccines against vNDV are readily available and potentially protective; nevertheless, improved vaccination protocols are required to prevent clinical disease and discontinue the spread of the virus. This study assessed the effectiveness of two commercial recombinant herpesvirus of turkey vector vaccines (rHVT-NDV-IBDV) that express the fusion (F) protein of NDV and the virus protein 2 (VP2) of infectious bursal disease virus (IBDV). In commercial broilers with maternally-derived antibodies (MDAs) the efficacy of the rHVT-NDV-IBDV vaccines was evaluated when administered alone, in combination with live-attenuated NDV vaccine at one-day-old, or as part of a prime/boost strategy. The vaccinated birds were challenged with the genotype VIId vNDV strain (NDV/chicken/Egypt/1/2015) at various ages (14, 24 and 35 days). In comparison to sham-vaccinated control birds, the applied vaccination regimens were able to reduce or prevent mortality and virus shedding and clinical disease. Two weeks post-application, the two vector vaccines were serologically reactive with the MDAs and induced protective immune responses against the F protein. In the instance of early challenge at 14 days old, the combination of recombinant rHVT-NDV-IBDV with a live vaccine offered better protection and reduced virus shedding compared to the vector vaccine alone. Boosting with live NDV vaccine at 14 days old increased the protective effect of the vector vaccines and reduced virus shedding and the clinical index after challenge at 24 days old. Both combining and/or boosting with live vaccine together with the vector vaccine provided better protection and minimized virus shedding compared with vaccination with vector vaccine only in the instance of 5-week-old challenge.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9914805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.1080/03079457.2023.2177140
Cornelis J Vermeulen, Remco Dijkman, J J Sjaak de Wit, Berend-Jan Bosch, J A P Hans Heesterbeek, Gerdien van Schaik
Infectious bronchitis virus (IBV) is an avian pathogen from the Coronavirus family causing major health issues in poultry flocks worldwide. Because of its negative impact on health, performance, and bird welfare, commercial poultry are routinely vaccinated by administering live attenuated virus. However, field strains are capable of rapid adaptation and may evade vaccine-induced immunity. We set out to describe dynamics within and between lineages and assess potential escape from vaccine-induced immunity. We investigated a large nucleotide sequence database of over 1700 partial sequences of the S1 spike protein gene collected from clinical samples of Dutch chickens submitted to the laboratory of Royal GD between 2011 and 2020. Relative frequencies of the two major lineages GI-13 (793B) and GI-19 (QX) did not change in the investigated period, but we found a succession of distinct GI-19 sublineages. Analysis of dN/dS ratio over all sequences demonstrated episodic diversifying selection acting on multiple sites, some of which overlap predicted N-glycosylation motifs. We assessed several measures that would indicate divergence from vaccine strains, both in the overall database and in the two major lineages. However, the frequency of vaccine-homologous lineages did not decrease, no increase in genetic variation with time was detected, and the sequences did not grow more divergent from vaccine sequences in the examined time window. Concluding, our results show sublineage turnover within the GI-19 lineage and we demonstrate episodic diversifying selection acting on the partial sequence, but we cannot confirm nor rule out escape from vaccine-induced immunity.RESEARCH HIGHLIGHTSSuccession of GI-19 IBV variants in broiler populations.IBV lineages overrepresented in either broiler, or layer production chickens.Ongoing episodic selection at the IBV S1 spike protein gene sequence.Several positively selected codons coincident with N-glycosylation motifs.
{"title":"Genetic analysis of infectious bronchitis virus (IBV) in vaccinated poultry populations over a period of 10 years.","authors":"Cornelis J Vermeulen, Remco Dijkman, J J Sjaak de Wit, Berend-Jan Bosch, J A P Hans Heesterbeek, Gerdien van Schaik","doi":"10.1080/03079457.2023.2177140","DOIUrl":"https://doi.org/10.1080/03079457.2023.2177140","url":null,"abstract":"<p><p>Infectious bronchitis virus (IBV) is an avian pathogen from the Coronavirus family causing major health issues in poultry flocks worldwide. Because of its negative impact on health, performance, and bird welfare, commercial poultry are routinely vaccinated by administering live attenuated virus. However, field strains are capable of rapid adaptation and may evade vaccine-induced immunity. We set out to describe dynamics within and between lineages and assess potential escape from vaccine-induced immunity. We investigated a large nucleotide sequence database of over 1700 partial sequences of the S1 spike protein gene collected from clinical samples of Dutch chickens submitted to the laboratory of Royal GD between 2011 and 2020. Relative frequencies of the two major lineages GI-13 (793B) and GI-19 (QX) did not change in the investigated period, but we found a succession of distinct GI-19 sublineages. Analysis of dN/dS ratio over all sequences demonstrated episodic diversifying selection acting on multiple sites, some of which overlap predicted N-glycosylation motifs. We assessed several measures that would indicate divergence from vaccine strains, both in the overall database and in the two major lineages. However, the frequency of vaccine-homologous lineages did not decrease, no increase in genetic variation with time was detected, and the sequences did not grow more divergent from vaccine sequences in the examined time window. Concluding, our results show sublineage turnover within the GI-19 lineage and we demonstrate episodic diversifying selection acting on the partial sequence, but we cannot confirm nor rule out escape from vaccine-induced immunity.<b>RESEARCH HIGHLIGHTS</b>Succession of GI-19 IBV variants in broiler populations.IBV lineages overrepresented in either broiler, or layer production chickens.Ongoing episodic selection at the IBV S1 spike protein gene sequence.Several positively selected codons coincident with N-glycosylation motifs.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10243407/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9586837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.1080/03079457.2022.2162368
Kobe Buyse, Evelyne Delezie, Axelle Govaert, Leen Van Brantegem, Nathalie Sleeckx, Koen Chiers, An Garmyn
There is a trend towards extended periods of lay in the laying hen industry. Extended cycles without a moulting stage gives the opportunity to obtain more eggs from a single hen. However, appropriate management and care for older laying hens is needed. In this trial we assessed the prevalence of conditions in old laying hens with a focus on neoplastic diseases. In total 150 ISA Brown and 150 Dekalb white laying hens were selected at 86 weeks of age. Of each hen line, 75 hens were necropsied at 86 weeks of age; the other half were monitored for 44 weeks after which they were necropsied. At week 86, 15.3% of the hens suffered from a neoplasm, ISA Brown being the most affected. During the follow up period, 50 birds died because of a natural cause of which 20 hens showed signs of a neoplasms. At the end of the follow up period, 43% of the hens were affected by a neoplasm. Adenocarcinoma was the most prevalent neoplasm and equally distributed among both hen lines. Leiomyomas were most frequently observed in ISA brown hens. Among causes of death, 19.05% of ISA brown and 20.69% of Dekalb White was attributed to a neoplasm. Furthermore, link with ovarian activity and other pathologies were made with significant correlations between adenocarcinomas and inactive ovaries. In conclusion, this study shows that the prevalence of adenocarcinoma and leiomyoma is a factor to be considered in longer laying cycles with 1/5th of the mortality caused by these processes.RESEARCH HIGHLIGHTSAt 86 weeks of age, the prevalence of neoplasms was 15.3%, mainly in brown hens.At 130 weeks of age, 43% of the hens were affected by a neoplasm.Adenocarcinoma was the most prevalent neoplasm equally distributed among hen lines.Leiomyoma was the second most prevalent neoplasm, mainly found in brown hens.
{"title":"An exploratory study on the prevalence of neoplasms in two strains of laying hens during an extended production cycle.","authors":"Kobe Buyse, Evelyne Delezie, Axelle Govaert, Leen Van Brantegem, Nathalie Sleeckx, Koen Chiers, An Garmyn","doi":"10.1080/03079457.2022.2162368","DOIUrl":"https://doi.org/10.1080/03079457.2022.2162368","url":null,"abstract":"<p><p>There is a trend towards extended periods of lay in the laying hen industry. Extended cycles without a moulting stage gives the opportunity to obtain more eggs from a single hen. However, appropriate management and care for older laying hens is needed. In this trial we assessed the prevalence of conditions in old laying hens with a focus on neoplastic diseases. In total 150 ISA Brown and 150 Dekalb white laying hens were selected at 86 weeks of age. Of each hen line, 75 hens were necropsied at 86 weeks of age; the other half were monitored for 44 weeks after which they were necropsied. At week 86, 15.3% of the hens suffered from a neoplasm, ISA Brown being the most affected. During the follow up period, 50 birds died because of a natural cause of which 20 hens showed signs of a neoplasms. At the end of the follow up period, 43% of the hens were affected by a neoplasm. Adenocarcinoma was the most prevalent neoplasm and equally distributed among both hen lines. Leiomyomas were most frequently observed in ISA brown hens. Among causes of death, 19.05% of ISA brown and 20.69% of Dekalb White was attributed to a neoplasm. Furthermore, link with ovarian activity and other pathologies were made with significant correlations between adenocarcinomas and inactive ovaries. In conclusion, this study shows that the prevalence of adenocarcinoma and leiomyoma is a factor to be considered in longer laying cycles with 1/5th of the mortality caused by these processes.<b>RESEARCH HIGHLIGHTS</b>At 86 weeks of age, the prevalence of neoplasms was 15.3%, mainly in brown hens.At 130 weeks of age, 43% of the hens were affected by a neoplasm.Adenocarcinoma was the most prevalent neoplasm equally distributed among hen lines.Leiomyoma was the second most prevalent neoplasm, mainly found in brown hens.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9543526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.1080/03079457.2023.2191833
J Lüning, D Wunderl, S Rautenschlein, A Campe
Histomonosis has become an important disease of turkeys since the ban of effective feed additives and therapeutics. Some critical risk factors for pathogen introduction into a farm have already been identified but open questions remain. Therefore, a retrospective case-control-study was used to identify the most significant risk factors for Histomonas (H.) meleagridis-introduction into a turkey farm. A total of 113 questionnaires were collected from 73 control-farms and 40 Histomonas-positive case-farms in Germany between 20 April 2021 and 31 January 2022. The data were analysed for possible risk factors by descriptive and univariate, single- and multi-factorial analysis. The presence of earthworms, snails and beetles, as vectors of H. meleagridis, as well as the proximity to other poultry-keeping farms in addition to a frequent observation of wild birds nearby the turkey farm, showed the highest risk potential for histomonosis outbreaks. Furthermore, poor biosecurity measures seem to have increased the probability for an outbreak. Insufficient climate management, straw as litter material and an inadequate litter refill frequency might have promoted a favourable humidity for vector- or pathogen survival providing important areas for improved disease control measures in the future.RESEARCH HIGHLIGHTSA retrospective case-control-study was conducted to identify impactful risk factors for a H. meleagridis introduction.The probability of a histomonosis outbreak was increased by the presence of vectors and reservoirs nearby a farm.Impactful risk factors concerning biosecurity measures, climate and litter management were identified.
{"title":"Histomonosis in German turkey flocks: possible ways of pathogen introduction.","authors":"J Lüning, D Wunderl, S Rautenschlein, A Campe","doi":"10.1080/03079457.2023.2191833","DOIUrl":"https://doi.org/10.1080/03079457.2023.2191833","url":null,"abstract":"<p><p>Histomonosis has become an important disease of turkeys since the ban of effective feed additives and therapeutics. Some critical risk factors for pathogen introduction into a farm have already been identified but open questions remain. Therefore, a retrospective case-control-study was used to identify the most significant risk factors for <i>Histomonas (H.) meleagridis-</i>introduction into a turkey farm. A total of 113 questionnaires were collected from 73 control-farms and 40 <i>Histomonas</i>-positive case-farms in Germany between 20 April 2021 and 31 January 2022. The data were analysed for possible risk factors by descriptive and univariate, single- and multi-factorial analysis. The presence of earthworms, snails and beetles, as vectors of <i>H. meleagridis</i>, as well as the proximity to other poultry-keeping farms in addition to a frequent observation of wild birds nearby the turkey farm, showed the highest risk potential for histomonosis outbreaks. Furthermore, poor biosecurity measures seem to have increased the probability for an outbreak. Insufficient climate management, straw as litter material and an inadequate litter refill frequency might have promoted a favourable humidity for vector- or pathogen survival providing important areas for improved disease control measures in the future.<b>RESEARCH HIGHLIGHTS</b>A retrospective case-control-study was conducted to identify impactful risk factors for a <i>H. meleagridis</i> introduction.The probability of a histomonosis outbreak was increased by the presence of vectors and reservoirs nearby a farm.Impactful risk factors concerning biosecurity measures, climate and litter management were identified.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9913950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Avian pathogenic E. coli (APEC) is a common pathogen in the poultry industry, which can cause substantial economic losses. Recently, emerging evidence showed that miRNAs were involved in various viral and bacterial infections. To elucidate the role of miRNAs in chicken macrophages in response to APEC infection, we attempted to investigate the miRNAs expression pattern upon APEC infection via miRNA-seq, and to identify the molecular mechanism of the important miRNAs by using RT-qPCR, western blotting, dual-luciferase reporter assay, and CCK-8. The results showed that a total of 80 differentially expressed (DE) miRNAs were identified in comparison of APEC vs. wild-type group, which corresponded to 724 target genes. Moreover, the target genes of the identified DE miRNAs were mainly significantly enriched in the MAPK signalling pathway, autophagy-bird, mTOR signalling pathway, ErbB signalling pathway, Wnt signalling pathway, and TGF-beta signalling pathway. Remarkably, gga-miR-181b-5p is able to participate in host immune and inflammatory responses against APEC infection via targeting of TGFBR1 to modulate the activation of TGF-beta signalling pathway. Collectively, this study provides a perspective of miRNA expression patterns in chicken macrophages upon APEC infection. These findings provide insight into miRNAs against APEC infection, and gga-miR-181b-5p might be a potential target for treating APEC infection.
{"title":"Identification and characterization of microRNAs, especially gga-miR-181b-5p, in chicken macrophages associated with avian pathogenic <i>E. coli</i> infection.","authors":"Yexin Yang, Yue Lu, Yuyang Zhou, Hongyan Sun, Yuyi Ma, Jishuang Tan, Naying Li, Huan Li","doi":"10.1080/03079457.2023.2181146","DOIUrl":"https://doi.org/10.1080/03079457.2023.2181146","url":null,"abstract":"<p><p>Avian pathogenic <i>E. coli</i> (APEC) is a common pathogen in the poultry industry, which can cause substantial economic losses. Recently, emerging evidence showed that miRNAs were involved in various viral and bacterial infections. To elucidate the role of miRNAs in chicken macrophages in response to APEC infection, we attempted to investigate the miRNAs expression pattern upon APEC infection via miRNA-seq, and to identify the molecular mechanism of the important miRNAs by using RT-qPCR, western blotting, dual-luciferase reporter assay, and CCK-8. The results showed that a total of 80 differentially expressed (DE) miRNAs were identified in comparison of APEC vs. wild-type group, which corresponded to 724 target genes. Moreover, the target genes of the identified DE miRNAs were mainly significantly enriched in the MAPK signalling pathway, autophagy-bird, mTOR signalling pathway, ErbB signalling pathway, Wnt signalling pathway, and TGF-beta signalling pathway. Remarkably, gga-miR-181b-5p is able to participate in host immune and inflammatory responses against APEC infection via targeting of <i>TGFBR1</i> to modulate the activation of TGF-beta signalling pathway. Collectively, this study provides a perspective of miRNA expression patterns in chicken macrophages upon APEC infection. These findings provide insight into miRNAs against APEC infection, and gga-miR-181b-5p might be a potential target for treating APEC infection.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9541637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ascaridia galli is an important nematode that causes ascaridiasis in free-range and indoor system chicken farms. Infection with A. galli may damage the intestinal mucosa and inhibit nutrient absorption, leading to a reduced growth rate, weight loss and a decreased egg production. Consequently, A. galli infection is a significant health problem in chickens. In this study, we developed a loop-mediated isothermal amplification coupled with a lateral flow dipstick (LAMP-LFD) assay for the visual detection of A. galli eggs in faecal samples. The LAMP-LFD assay consists of six primers and one DNA probe that recognize the internal transcribed spacer 2 (ITS2) region; it can be performed within 70 min and the results can be interpreted with the naked eye. Using the LAMP-LFD assay developed in this study, A. galli DNA was specifically amplified without any cross-reactions with other related parasites (Heterakis gallinarum, Raillietina echinobothrida, R. tetragona, R. cesticillus, Cotugnia sp., Echinostoma miyagawai) and definitive hosts (Gallus gallus domesticus, Anas platyrhynchos domesticus). The minimum detectable DNA concentration was 5 pg/μl, and the detectable egg count was 50 eggs per reaction. The assay can be performed in a water bath, without the need for post-mortem morphological investigations and laboratory instruments. It is therefore a viable alternative for the detection of A. galli in chicken faeces and can replace classical methods in field screening for epidemiological investigations, veterinary health and poultry farming management.RESEARCH HIGHLIGHTSThis is the first study using the LAMP-LFD assay for Ascaridia galli detection.The results can be observed by the naked eye.The developed assay can be used to detect Ascaridia galli eggs in faecal samples.
鸡瘿蛔虫是引起散养和室内系统鸡场蛔虫病的重要线虫。感染大肠杆菌可损害肠黏膜,抑制营养吸收,导致生长速度减慢、体重减轻和产蛋量下降。因此,鸡的大肠杆菌感染是一个重要的健康问题。在这项研究中,我们开发了一种环介导的等温扩增结合侧流试纸(LAMP-LFD)方法,用于粪便样本中galli卵的视觉检测。LAMP-LFD检测包括6个引物和一个识别内部转录间隔区2 (ITS2)区域的DNA探针;可以在70分钟内完成,结果可以用肉眼解释。本研究利用LAMP-LFD方法,特异性扩增出了galli的DNA,与其他相关寄生虫(Heterakis gallinarum, Raillietina echinobothrida, R. tetragona, R. cesticillus, Cotugnia sp., Echinostoma miagawai)和最终宿主(Gallus Gallus, Anas platyrhynchos domesticus)无交叉反应。最低DNA检测浓度为5 pg/μl,每个反应可检测到50个卵。该分析可以在水浴中进行,而不需要尸检形态学调查和实验室仪器。因此,它是一种可行的替代方法,可用于检测鸡粪便中的加利利杆菌,并可在流行病学调查、兽医卫生和家禽养殖管理的现场筛查中取代传统方法。这是第一个使用LAMP-LFD检测加利蛔虫的研究。结果可以用肉眼观察到。该方法可用于粪便样品中加利蛔虫卵的检测。
{"title":"Feasibility of a DNA biosensor assay based on loop-mediated isothermal amplification combined with a lateral flow dipstick assay for the visual detection of <i>Ascaridia galli</i> eggs in faecal samples.","authors":"Wasin Panich, Thanawan Tejangkura, Thapana Chontananarth","doi":"10.1080/03079457.2023.2196251","DOIUrl":"https://doi.org/10.1080/03079457.2023.2196251","url":null,"abstract":"<p><p><i>Ascaridia galli</i> is an important nematode that causes ascaridiasis in free-range and indoor system chicken farms. Infection with <i>A. galli</i> may damage the intestinal mucosa and inhibit nutrient absorption, leading to a reduced growth rate, weight loss and a decreased egg production. Consequently, <i>A. galli</i> infection is a significant health problem in chickens. In this study, we developed a loop-mediated isothermal amplification coupled with a lateral flow dipstick (LAMP-LFD) assay for the visual detection of <i>A. galli</i> eggs in faecal samples. The LAMP-LFD assay consists of six primers and one DNA probe that recognize the internal transcribed spacer 2 (ITS2) region; it can be performed within 70 min and the results can be interpreted with the naked eye. Using the LAMP-LFD assay developed in this study, <i>A. galli</i> DNA was specifically amplified without any cross-reactions with other related parasites (<i>Heterakis gallinarum</i>, <i>Raillietina echinobothrida</i>, <i>R. tetragona</i>, <i>R. cesticillus</i>, <i>Cotugnia</i> sp., <i>Echinostoma miyagawai</i>) and definitive hosts (<i>Gallus gallus domesticus</i>, <i>Anas platyrhynchos domesticus</i>). The minimum detectable DNA concentration was 5 pg/μl, and the detectable egg count was 50 eggs per reaction. The assay can be performed in a water bath, without the need for <i>post-mortem</i> morphological investigations and laboratory instruments. It is therefore a viable alternative for the detection of <i>A. galli</i> in chicken faeces and can replace classical methods in field screening for epidemiological investigations, veterinary health and poultry farming management.<b>RESEARCH HIGHLIGHTS</b>This is the first study using the LAMP-LFD assay for <i>Ascaridia galli</i> detection.The results can be observed by the naked eye.The developed assay can be used to detect <i>Ascaridia galli</i> eggs in faecal samples.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9543284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.1080/03079457.2023.2196258
Erica Spackman, Mary J Pantin-Jackwood, Scott A Lee, Diann Prosser
Highly pathogenic (HP) avian influenza viruses (AIVs) of the clade 2.3.4.4 goose/Guangdong/1996 H5 lineage continue to be a problem in poultry and wild birds in much of the world. The recent incursion of a H5N1 clade 2.3.4.4b HP AIV from this lineage into North America has resulted in widespread outbreaks in poultry and consistent detections of the virus across diverse families of birds and occasionally mammals. To characterize the pathobiology of this virus in mallards (Anas platyrhynchos), which are a primary reservoir of AIV, a challenge study was conducted with 2-week-old birds. The 50% bird infectious dose was determined to be < 2 log10 50% egg infectious doses (EID50) and all exposed ducks, including ducks co-housed with inoculated ducks, were infected. Infection appeared to be subclinical for 58.8% (20/34) of the ducks, one duck was lethargic, about 20% developed neurological signs and were euthanized, and 18% developed corneal opacity. The mallards shed virus by both the oral and cloacal routes within 24-48 h post-infection. Oral shedding substantially decreased by 6-7 days post-infection, but 65% of the ducks continued to shed virus cloacally through 14 days post-exposure (DPE) for the direct inoculates and 13 DPE for contact-exposed ducks. Based on the high transmissibility, high virus shed titres, and mild-to-moderate disease, mallards could serve as efficient reservoirs to amplify and disseminate recent North American clade 2.3.4.4b viruses.
2.3.4.4鹅/广东/1996 H5谱系的高致病性禽流感病毒(HP)在世界大部分地区的家禽和野生鸟类中仍然是一个问题。最近,H5N1分支2.3.4.4b HP AIV从该谱系传入北美,导致家禽中广泛暴发,并在不同鸟类科和偶尔的哺乳动物中持续检测到该病毒。野鸭是AIV的主要宿主,为了描述这种病毒在野鸭(Anas platyrhynchos)中的病理生物学特征,对2周龄的禽类进行了一项挑战研究。禽鸟50%感染剂量小于2 log10 50%蛋感染剂量(EID50),所有暴露鸭,包括与接种鸭同住的鸭均被感染。58.8%(20/34)的鸭出现亚临床感染,1只鸭嗜睡,约20%的鸭出现神经症状并被安乐死,18%的鸭出现角膜混浊。在感染后的24-48小时内,绿头鸭通过口腔和肛肠途径传播病毒。在感染后6-7天内,口腔病毒传播显著减少,但65%的鸭子在接触后14天(DPE)和接触后13天(DPE)继续在局部传播病毒。基于高传播性、高病毒滴度和轻至中度疾病特征,野鸭可作为北美新近进化支2.3.4.4b病毒的有效宿主进行扩增和传播。
{"title":"The pathogenesis of a 2022 North American highly pathogenic clade 2.3.4.4b H5N1 avian influenza virus in mallards (<i>Anas platyrhynchos</i>).","authors":"Erica Spackman, Mary J Pantin-Jackwood, Scott A Lee, Diann Prosser","doi":"10.1080/03079457.2023.2196258","DOIUrl":"https://doi.org/10.1080/03079457.2023.2196258","url":null,"abstract":"<p><p>Highly pathogenic (HP) avian influenza viruses (AIVs) of the clade 2.3.4.4 goose/Guangdong/1996 H5 lineage continue to be a problem in poultry and wild birds in much of the world. The recent incursion of a H5N1 clade 2.3.4.4b HP AIV from this lineage into North America has resulted in widespread outbreaks in poultry and consistent detections of the virus across diverse families of birds and occasionally mammals. To characterize the pathobiology of this virus in mallards (<i>Anas platyrhynchos</i>), which are a primary reservoir of AIV, a challenge study was conducted with 2-week-old birds. The 50% bird infectious dose was determined to be < 2 log<sub>10</sub> 50% egg infectious doses (EID<sub>50</sub>) and all exposed ducks, including ducks co-housed with inoculated ducks, were infected. Infection appeared to be subclinical for 58.8% (20/34) of the ducks, one duck was lethargic, about 20% developed neurological signs and were euthanized, and 18% developed corneal opacity. The mallards shed virus by both the oral and cloacal routes within 24-48 h post-infection. Oral shedding substantially decreased by 6-7 days post-infection, but 65% of the ducks continued to shed virus cloacally through 14 days post-exposure (DPE) for the direct inoculates and 13 DPE for contact-exposed ducks. Based on the high transmissibility, high virus shed titres, and mild-to-moderate disease, mallards could serve as efficient reservoirs to amplify and disseminate recent North American clade 2.3.4.4b viruses.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9596425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.1080/03079457.2023.2181145
Louis H Maartens, Leticia Frizzo da Silva, Susan Dawson, Nicolette Love, Baltus J Erasmus
Highly pathogenic avian influenza (HPAI) viruses from the Goose/Guangdong/96-lineage emerged in Southeast Asia and subsequently spread to the Middle East, Africa and Europe, infecting a range of birds and mammals (including humans). This lineage of H5 viruses can efficiently establish itself in wild birds after circulating among gallinaceous poultry, facilitating reassortment with low pathogenic avian influenza (LPAI) virus strains, enhancing dispersal over long distances and contributing to endemicity. The detection of HPAI H5N8 virus (clade 2.3.4.4B) in 2017 in the Mpumalanga Province of South Africa marked the beginning of an epidemic that devastated the South African poultry industry. Vaccines were tested to assess protection against the circulating field strain. This article describes the performance of a reverse genetics inactivated H5N1 vaccine from Zoetis (RG-H5N1), with 96.1% identity to the circulating HPAI H5N8 virus. Two locally formulated benchmarks, one containing an H5N8 antigen homologous to the field strain (Benchmark-H5N8), the other containing a heterologous (87.6% identity to field virus) LPAI H5N1 antigen (Benchmark-H5N1), were included for comparison. Efficacy was assessed in specific pathogen-free (SPF) chickens using a prime-boost approach (injections at days 21 and 45), followed by a challenge with a South African HPAI H5N8 isolate (70 days of age). The Zoetis RG-H5N1 vaccine and Benchmark-H5N8 outperformed the Benchmark-H5N1 in terms of humoral response against the H5N8 antigen and reduction of shedding. The Zoetis RG-H5N1 vaccine protected 100% of the chickens against clinical disease and death. This study confirmed that antigenically matched inactivated vaccines could induce robust protection and markedly reduce viral shedding.RESEARCH HIGHLIGHTSConditionally licensed vaccine protected against HPAI H5N8 (clade 2.3.4.4B).Complete protection against clinical disease and mortality.Drastic reduction of viral shedding after challenge.
{"title":"The efficacy of an inactivated avian influenza H5N1 vaccine against an African strain of HPAI H5N8 (clade 2.3.4.4 B).","authors":"Louis H Maartens, Leticia Frizzo da Silva, Susan Dawson, Nicolette Love, Baltus J Erasmus","doi":"10.1080/03079457.2023.2181145","DOIUrl":"https://doi.org/10.1080/03079457.2023.2181145","url":null,"abstract":"<p><p>Highly pathogenic avian influenza (HPAI) viruses from the Goose/Guangdong/96-lineage emerged in Southeast Asia and subsequently spread to the Middle East, Africa and Europe, infecting a range of birds and mammals (including humans). This lineage of H5 viruses can efficiently establish itself in wild birds after circulating among gallinaceous poultry, facilitating reassortment with low pathogenic avian influenza (LPAI) virus strains, enhancing dispersal over long distances and contributing to endemicity. The detection of HPAI H5N8 virus (clade 2.3.4.4B) in 2017 in the Mpumalanga Province of South Africa marked the beginning of an epidemic that devastated the South African poultry industry. Vaccines were tested to assess protection against the circulating field strain. This article describes the performance of a reverse genetics inactivated H5N1 vaccine from Zoetis (RG-H5N1), with 96.1% identity to the circulating HPAI H5N8 virus. Two locally formulated benchmarks, one containing an H5N8 antigen homologous to the field strain (Benchmark-H5N8), the other containing a heterologous (87.6% identity to field virus) LPAI H5N1 antigen (Benchmark-H5N1), were included for comparison. Efficacy was assessed in specific pathogen-free (SPF) chickens using a prime-boost approach (injections at days 21 and 45), followed by a challenge with a South African HPAI H5N8 isolate (70 days of age). The Zoetis RG-H5N1 vaccine and Benchmark-H5N8 outperformed the Benchmark-H5N1 in terms of humoral response against the H5N8 antigen and reduction of shedding. The Zoetis RG-H5N1 vaccine protected 100% of the chickens against clinical disease and death. This study confirmed that antigenically matched inactivated vaccines could induce robust protection and markedly reduce viral shedding.<b>RESEARCH HIGHLIGHTS</b>Conditionally licensed vaccine protected against HPAI H5N8 (clade 2.3.4.4B).Complete protection against clinical disease and mortality.Drastic reduction of viral shedding after challenge.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9596466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}