Avian Pathology最新文献

{"title":"Copper nanoparticles effectively reduce <i>Salmonella</i> Enteritidis in broiler chicken diet and water.","authors":"Karine Patrin Pontin, Karen Apellanis Borges, Thales Quedi Furian, Gabriela Zottis Chitolina, Roberta de Castro Böhnmann, Ronise Faria Rohde Depner, Ines Andretta, Danrlei Nogueira, Daiane Elisa Wilsmann, Daniela Tonini da Rocha, Hamilton Luiz de Souza Moraes, Vladimir Pinheiro do Nascimento","doi":"10.1080/03079457.2024.2409446","DOIUrl":"10.1080/03079457.2024.2409446","url":null,"abstract":"<p><p>The use of copper nanoparticles (CuNP) in the diet of broiler chickens has been studied as a potential alternative to antibiotic growth promoters. This study aimed to analyse the antimicrobial properties of CuNP in the feed and water of broiler chickens against <i>Salmonella</i> Enteritidis and to assess the intestinal integrity and toxicity of CuNP supplementation in their diet. The antimicrobial activity of CuNP against <i>S.</i> Enteritidis was tested in microplates to evaluate three water samples with different mineral compositions and in an <i>in vitro</i> digestibility model that simulated the three primary intestinal compartments of birds to assess feed samples. To evaluate <i>in vivo</i> intestinal integrity and toxicity, the birds were divided into four groups (30 birds per group): (1) basal diet (control); (2) basal diet + CuNP (100 ppm); (3) basal diet + enramycin (10 ppm); and (4) basal diet + CuNP (100 ppm) + enramycin (10 ppm). Intestinal samples were collected for histomorphometric evaluation and lactic acid bacteria count, while chest muscle and whole blood samples were collected to determine copper content. A significant reduction in the <i>S.</i> Enteritidis count was observed in both <i>in vitro</i> treatments (water and feed) with CuNP inclusion, compared to the control group. No significant differences in histomorphometric measurements, weight gain, or total lactic acid bacterial counts were found compared to those in the control. These results demonstrate the effectiveness of CuNP in reducing the occurrence of <i>S.</i> Enteritidis and their non-interference with the intestinal integrity of broiler chickens, highlighting the potential of CuNP as an alternative antimicrobial agent in the poultry production chain.<b>RESEARCH HIGHLIGHTS</b>Supplementation with CuNP in feed and water reduced <i>Salmonella</i> Enteritidis count.Supplementation with CuNP did not affect intestinal integrity of broilers.CuNP did not affect weight gain or total lactic acid bacterial counts.The results demonstrate the potential of CuNP as alternative antimicrobials.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"212-222"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142340392","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}

{"title":"Age of challenge is important in <i>Salmonella</i> Enteritidis studies in pullets and hens: a systematic review.","authors":"Wing Y J Yue, Peter J Groves","doi":"10.1080/03079457.2024.2410873","DOIUrl":"10.1080/03079457.2024.2410873","url":null,"abstract":"<p><p>Nontyphoidal serovars of <i>Salmonella enterica</i> subsp <i>enterica</i> frequently colonize the intestinal tracts of chickens, creating risks of contamination of meat and egg food products. These serovars seldom cause disease in chickens over 3 weeks of age. Colonization is generally transient but can continue to circulate in a flock for many months. Vaccination of breeders and layers is the most effective method of control of infections with serovars Enteritidis and Typhimurium, and the development of these vaccines or other preventative treatments requires challenge studies to demonstrate efficacy. However, establishing a successful challenge model where the control birds are colonized to a sufficient extent to be able to demonstrate a statistically significant reduction from the vaccine or treatment is problematic. A meta-analysis of published <i>S</i>. Enteritidis challenge studies was performed to pursue the best challenge model conditions that provide consistent control colonization outcomes. Challenge at sexual maturity was significantly more effective in achieving at least 80% colonization of control hens.<b>RESEARCH HIGHLIGHTS</b><i>Salmonella</i> challenge chicken models do not always achieve high colonization levels in controls.The age of hen is important in achieving good caecal colonization.Challenge around sexual maturity provides the best control colonization outcome.A challenge dose rate of 10⁵ CFU/ bird is adequate in birds under 30 weeks of age.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"159-167"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142399170","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}

{"title":"Identification and characterization of chicken TRIM45 and its role as a negative regulator of ALV-J replication <i>in vitro</i>.","authors":"Jiaxing Wang, Qiangzhou Wang, Yuyu Ping, Xuan Huang, Ting Yang, Yulin Bi, Guobin Chang, Shihao Chen","doi":"10.1080/03079457.2024.2419039","DOIUrl":"10.1080/03079457.2024.2419039","url":null,"abstract":"<p><p>Avian leukosis virus subgroup J (ALV-J) is an alpharetrovirus that infects chickens, causing immunosuppression and a decrease in production performance, leading to substantial economic losses in the poultry industry. ALV-J is also well-known for its oncogenic properties, inducing tumours such as myelomas and haemangiomas in infected chickens. TRIM45 has been identified as a potential tumour suppressor; however, the relationship between TRIM45 expression and ALV-J infection remains to be elucidated. This study aimed to dissect the molecular characteristics of the chicken TRIM45 gene and its modulation during ALV-J infection, as well as its influence on viral replication. We found that the chicken TRIM45 RING domain is significantly different from that of humans and other mammals. TRIM45 is expressed in all chicken tissues, with the highest levels in the heart. Subcellular localization studies indicated a cytoplasmic distribution of TRIM45, forming aggregates within cells. Our findings demonstrate that ALV-J infection significantly upregulates TRIM45 expression in DF-1 cells. To assess the functional role of TRIM45 in ALV-J replication, we employed both gene silencing and overexpression strategies. Strikingly, the overexpression of TRIM45, including a mutant lacking the RING domain, was found to markedly suppress ALV-J replication. In contrast, TRIM45 knockdown via siRNA resulted in an enhanced viral replication, highlighting the importance of TRIM45 limiting ALV-J replication. Mechanistically, overexpression of TRIM45 induces apoptosis in infected cells, independent of its RING domain function. In conclusion, our study demonstrates that chicken TRIM45 acts as a negative regulator of ALV-J replication <i>in vitro</i> by promoting apoptosis in infected cells.<b>RESEARCH HIGHLIGHTS</b>Chicken TRIM45 RING domain and protein localization significantly differ from humans.TRIM45 negatively regulates ALV-J replication <i>in vitro</i>.TRIM45 inhibits ALV-J replication by inducing apoptosis in infected cells.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"255-264"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142457020","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}

{"title":"Novel goose parvovirus in naturally infected ducks suffering from locomotor disorders: molecular detection, histopathological examination, immunohistochemical signals, and full genome sequencing.","authors":"Mohamed A Lebdah, Amal A M Eid, Reham M ElBakrey, Abd Elgalil El-Gohary, Mohamed R Mousa, Hagar F Gouda, Ahmed F Gad, Sarah S Helal, Mohamed G Seadawy","doi":"10.1080/03079457.2024.2419038","DOIUrl":"10.1080/03079457.2024.2419038","url":null,"abstract":"<p><p>In this study, we investigated the pathological effects of novel goose parvovirus (NGPV) infection on the skeletal muscle, brain, and intestine of naturally affected ducks suffering from locomotor dysfunction as a new approach for a deeper understanding of this clinical form. For this purpose, a total of 97 diseased ducks, representing 24 flocks of different duck breeds (14-75 days old), were clinically examined. In total, 72 tissue pools of intestine, brain, and skeletal muscle samples were submitted for molecular identification. Typical clinical signs among the examined ducks suggested parvovirus infection. Regarding <i>postmortem</i> examination, all examined ducks showed muscle emaciation (100%) either accompanied by congestion (34%) or paleness (66%). Slight congestion, either in the brain (82.5%) or intestine (75.25%), was predominantly detected. Based on molecular identification, the intestine had the highest percentage of positive detection (91.7%), followed by the skeletal muscle (70.8%), and the brain (20.8%). The main histopathological alterations were myofibre atrophy and degeneration, marked enteritis accompanied by lymphocytic infiltration in the lamina propria and submucosa, while the affected brains showed vasculitis, diffuse gliosis, and Purkinje cell degeneration in the cerebellum. Next-generation sequencing further confirmed the presence of a variant strain of goose parvovirus (vGPV) that is globally known as NGPV and closely related to Chinese NGPV isolates. Using immunohistochemistry, the NGPV antigen was positively detected in the muscle fibres, enterocytes, and Purkinje cells in the cerebellum. These findings provided proof of the involvement of virus replication in the locomotor disorders linked to NGPV infection in ducks.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"241-254"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142457021","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}

{"title":"Comparative meta-analysis of prevalence and molecular features of high-priority <i>Enterococcus faecium</i> and <i>E. faecalis</i> from the guts of food-producing and wild birds.","authors":"Idris Nasir Abdullahi, Islem Trabelsi","doi":"10.1080/03079457.2025.2485106","DOIUrl":"https://doi.org/10.1080/03079457.2025.2485106","url":null,"abstract":"<p><strong>Background: </strong>Birds harbor <i>Enterococcus faecium</i> and <i>Enterococcus faecalis</i> as gut commensals but could acquire and transmit high-priority strains.</p><p><strong>Methods: </strong>Following the PRISMA guidelines, eligible studies that reported the antimicrobial resistance (AMR) profiles of <i>E. faecium</i> and <i>E. faecalis</i> from gut samples of food-producing (FPBs) and wild birds (WBs) published from 2005 to 2024 were screened from major bibliographic databases. Random-effect models were used to determine the pooled prevalences (PPs) of vancomycin (VAN^R), ampicillin (AMP^R), and linezolid (LZD^R) resistant <i>E. faecium</i> and <i>E. faecalis</i> from non-duplicated gut samples of food-producing (FPBs) and wild birds (WBs).</p><p><strong>Results: </strong>Of the 36 eligible studies, the overall PP of VAN^R-<i>E. faecium</i> and VAN^R-<i>E. faecalis</i> were 1.8% and 0.7%, respectively. AMP^R-<i>E. faecium</i> and AMP^R-<i>E. faecalis</i> were 1.6% and 0.6%, respectively. LZD^R-<i>E. faecium</i> and LZD^R-<i>E. faecalis</i> were 1% and 0.8%, respectively. Subgroup analyses revealed significant temporal variations in the PPs of VAN^R-<i>E. faecium</i> (p < 0.05). FPBs had significantly higher PPs of VAN^R, AMP^R and LZD^R <i>E. faecium</i> and <i>E. faecalis</i> than WBs (p < 0.05). Healthcare-associated <i>vanA</i>-carrying <i>E. faecium</i> lineages from WBs (ST16, ST17, ST18, and ST412) and <i>optrA</i>-carrying <i>E. faecalis</i> lineages (ST32, ST59, ST330) from FPBs were identified. In FPBs, Egypt had the highest PP of VAN^R-<i>E. faecium</i> (11.9%) and LZD^R-<i>E. faecalis</i> (2.8%). Conversely, the USA had the highest PP of VAN^R-<i>E. faecium</i> in WBs (2.4%).</p><p><strong>Conclusions: </strong>A higher frequency of vancomycin- than linezolid-resistant strains exists, and VAN^R-<i>E. faecium</i> are disproportionately distributed based on bird species, years of study, and countries, indicating varied selection pressure. Significantly higher prevalence of VAN^R-<i>E. faecium</i> than VAN^R-<i>E. faecalis</i> was found, highlighting the higher capacity of <i>E. faecium</i> to acquire ampicillin and vancomycin resistance in birds.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"1-54"},"PeriodicalIF":2.5,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143708330","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}

{"title":"The host protein CCT8 interacts with PB2 protein of H9N2 AIV and facilitates virus replication.","authors":"Yiqin Cai, Ye Liu, Guihu Yin, Jianing Hu, Zichen Gao, Xinyu Guo, Ruiying Wang, Meng Zhong, Qingtao Liu, Xiuli Feng","doi":"10.1080/03079457.2025.2476511","DOIUrl":"https://doi.org/10.1080/03079457.2025.2476511","url":null,"abstract":"<p><strong>Research highlights: </strong>The host protein CCT8 interacts with the influenza virus protein PB2.The CCT8 gene is upregulated during influenza virus infection.Knockdown of CCT8 inhibits viral proliferation.Elevated expression of CCT8 facilitates viral proliferation.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"1-11"},"PeriodicalIF":2.5,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143708332","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}

{"title":"Characterization of immunopathological changes in the feather pulp of CVI988-vaccinated pullets challenged with a very virulent plus Marek's disease virus strain.","authors":"Federico C Bonorino, Juan Francisco Garcia Marin, Abdelhamid Fares, Nagwa Khaled, Deanna Emmanuel, Raveendra R Kulkarni, Isabel Gimeno","doi":"10.1080/03079457.2025.2472838","DOIUrl":"10.1080/03079457.2025.2472838","url":null,"abstract":"<p><p>High load of oncogenic Marek's disease virus (MDV) DNA in the feather pulp (FP) as early as 21 days of age is a powerful criterion to predict the outcome of Marek's disease (MD) in apparently healthy chickens. The objective of this study was to elucidate the immunopathological changes in the FP of 21-day-old chickens that had been vaccinated with CVI988 vaccine (healthy), vaccinated and challenged with a very virulent plus (vv+) MDV strain 648A (well protected), or were unvaccinated and challenged with 648A strain (not protected) when compared to uninfected naïve chickens. Oncogenic MDV DNA load, histopathological and immunohistochemical evaluation of the lesions, and immunophenotypic characterization of the infiltrates by flow cytometry were examined. Our results demonstrate that 648A-infected unvaccinated chickens had a significant increase in the percentage of CD3+ T cells, mainly CD4+MHC-II+ cells and CD8+MHC-II+ cells, when compared to all other groups. They also had a significantly decreased number of CD8β+ T cells compared to all other groups. Infection with 648A reduced the percentage of macrophages, not only in the unvaccinated group but also in the CVI988/648A group. In addition, groups that were vaccinated with CVI988, regardless of the challenge status, had higher levels of CD8β+ T cells, suggesting that the vaccine has an enhancing effect on the CTL cells. Our results showed that the load of oncogenic MDV is highly correlated with the infiltration of CD4+MHC-II+ cells and provide further confirmation that FP is indeed an appropriate sample for the early diagnosis of MD.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"1-9"},"PeriodicalIF":2.5,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143522585","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}

{"title":"CircITSN2-miR-17-5p/20a-5p/20b-5p-<i>PD-L1</i> regulatory network is a potential molecular mechanism of <i>PD-L1</i> gene involving in immune response to IBDV.","authors":"Yi Jiang, Yufei Tian, Jianwei Han, Xiangnan Wang, Rui Zhang, Xinxin Xu, Xiaoli Ma, Wei Zhang, Chaolai Man","doi":"10.1080/03079457.2025.2470754","DOIUrl":"10.1080/03079457.2025.2470754","url":null,"abstract":"<p><strong>Research highlights: </strong><i>PD-L1</i> gene is correlated with IBDV immune response in chickens.<i>PD-L1</i> is a key gene regulating the immune functions of the heart, lung, and proventriculus.CircITSN2-miR-17-5p/20a-5p/20b-5p-<i>PD-L1</i> is a potential mechanism in IBDV immunity.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"1-9"},"PeriodicalIF":2.5,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143466753","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}

{"title":"Recombinant autobioluminescent <i>Escherichia coli</i> to monitor the progression of <i>Escherichia coli</i> infection in the embryonated chicken eggs.","authors":"Mohamed Kamal Abdelhamid, Surya Paudel, Hammad Ur Rehman, Manolis Lyrakis, Ivana Bilic, Michael Hess, Claudia Hess","doi":"10.1080/03079457.2025.2477246","DOIUrl":"https://doi.org/10.1080/03079457.2025.2477246","url":null,"abstract":"<p><p><b>Abstract</b>Avian pathogenic <i>Escherichia coli</i> (APEC) infections in poultry adversely affect health and production, with public health implications. This study assessed the potential of bioluminescence imaging for real-time, noninvasive tracking of microbial progression in 12-day-old chicken embryos inoculated with an APEC strain or its derivatives integrated either with <i>lux</i>ABCDE or <i>ilux2</i> operon. Eggs were imaged daily for bioluminescence detection, with dead embryos sampled immediately and survivors killed at 5 days post inoculation (dpi). The eggs were opened, and egg contents were imaged for bioluminescence. Yolks were sampled for <i>E. coli</i> isolation and quantification. Results showed lethality rates of 100%, 93.3% and 80% in embryos inoculated with native strain, <i>lux</i>ABCDE or <i>ilux2,</i> respectively. Bioluminescence analysis showed increased bioluminescence signal strength over time preceding embryo death. Surviving embryos exhibited a sequential reduction in signal strength. A strong positive correlation was found between bioluminescence signal intensity <i>in ovo</i> and <i>ex ovo</i>, with <i>ilux2-</i>APEC infected eggs showing a higher luminoscore than <i>lux</i>ABCDE-APEC. The <i>E. coli</i> load in yolks of APEC-inoculated eggs showed a positive trend over time. Overall, bioluminescence imaging of <i>ilux2</i> operon labelled bacteria enabled more efficient real-time detection and monitoring of <i>E. coli in ovo</i>. Multiple imaging sessions on the same embryo throughout the experiment allow precise monitoring of infection progression without sequential culling. This offers a controlled platform for evaluating antimicrobial treatments' efficacy in an <i>in ovo</i> model that closely resembles <i>in vivo</i> environment in chickens. It also bears the potential to study other pathogens' infection patterns, especially those pose risks to public health.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"1-24"},"PeriodicalIF":2.5,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143603878","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}

{"title":"Impact of highly pathogenic avian influenza virus (HPAIV) on Black-headed Gulls <i>Chroicocephalus ridibundus</i> population in Poland in 2023.","authors":"Piotr Indykiewicz, Marcin Przymencki, Piotr Minias, Dariusz Jakubas, Klaudia Litwiniak, Piotr Zieliński, Tomasz Janiszewski, Radosław Włodarczyk, Mateusz Ledwoń, Jacek Nowakowski, Beata Dulisz, Katarzyna Domańska-Blicharz, Edyta Świętoń, Krzysztof Śmietanka, Dariusz Bukaciński, Monika Bukacińska, Arkadiusz Buczyński, Szymon Beuch, Tomasz Chodkiewicz, Jacek Betleja, Szymon Bzoma, Dominik Marchowski, Arkadiusz Sikora, Łukasz Bednarz, Jacek Antczak, Andrzej Dylik, Zbigniew Kajzer, Wiesław Król, Łukasz Krajewski, Sebastian Menderski, Jan Rapczyński, Sławomir Rubacha, Rafał Szczerbik, Jakub Szymczak, Kazimierz Walasz, Przemysław Wylegała","doi":"10.1080/03079457.2025.2467122","DOIUrl":"https://doi.org/10.1080/03079457.2025.2467122","url":null,"abstract":"<p><p>The highly pathogenic avian influenza virus (HPAIV) A(H5N1) has caused the most extensive and severe epizootic event affecting both poultry and wild birds globally. This study investigated the impact of HPAIV on the breeding population of the Black-headed Gull <i>Chroicocephalus ridibundus</i>, the most abundant gull species in Poland. During the 2023 outbreak, this species was reported as the most frequently infected in the country. A higher-than-natural adult mortality rate (greater than 1.5% of the breeding individuals) was observed in 114 surveyed colonies across all regions of Poland. Laboratory tests confirmed the presence of HPAIV in all 17 colonies sampled, with average adult mortality estimated at 26.1%, and ranging from 1.7% to 77.8%. The estimated mortality rate across all surveyed colonies was 22.2%. Extrapolations across the entire Polish breeding population (at least 115,000 pairs according to the national census) indicated that approximately 51,000 adult Black-headed Gulls might have perished due to HPAIV in 2023. The number of adults found dead was positively correlated with colony size (<i>r</i> = 0.733, <i>P</i> < 0.001). The deaths were associated with a single HPAIV genotype (BB) across all confirmed cases. Understanding the spread and severity of HPAIV in colonially breeding waterbirds, such as gulls, is essential for assessing the full extent of the threats this virus poses to wild bird populations.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"1-14"},"PeriodicalIF":2.5,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555730","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}