Avian Pathology最新文献

{"title":"Molecular and Pathological Evaluation of a Velogenic Newcastle Disease Virus Strain Circulating in Vietnam.","authors":"The Viet Hoang Nguyen, Ha Giang Nguyen, Tuyet Ngan Thai, Ngoc Duong Vu, Thi Chau Giang Tran, Nhat Huy Bui, Thi Tam Than, Hoang Duc Le, Moon Her, Hye-Ryoung Kim, Ji-Ye Kim, Van Phan Le","doi":"10.1080/03079457.2025.2570722","DOIUrl":"https://doi.org/10.1080/03079457.2025.2570722","url":null,"abstract":"<p><p>The Newcastle disease virus (NDV) poses a major challenge to poultry farming in Vietnam as it continues to threaten both economic and food security. Despite vaccination efforts, outbreaks caused by velogenic NDV strains continue to occur, indicating gaps in our understanding of the pathogenicity of these viruses. In this study, a velogenic NDV strain (genotype VII.2) was isolated from vaccinated chickens during an outbreak in southern Vietnam. Whole genome sequencing and phylogenetic analyses confirmed that this isolate belongs to a genotype associated with virulent NDV strains. The strain had an intracerebral pathogenicity index (ICPI) of 1.81 and a mean-death-time (MDT) of 56 hours. Experimental infection of domestic chickens showed a rapid onset of severe clinical signs, extensive tissue damage, and a high mortality rate, even in co-housed, uninfected chickens. Virus excretion via the oral cavity and cloaca of the experimental chickens facilitated rapid transmission within the flock. These results underscore the urgent need for enhanced epidemiological surveillance and tailored vaccination strategies to mitigate the impact of NDV outbreaks in Vietnam. This study provides important insights into the pathogenicity, transmission, and lesion profile of NDV genotype VII.2, contributing to the development of effective control measures.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"1-41"},"PeriodicalIF":2.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145231481","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":"Molecular epidemiology of IBDV in Italy: emergence of Northwestern European reassortants (genotype A3B1) and co-circulation with local strains.","authors":"Francesca Poletto, Gabriele Lizzi, Matteo Legnardi, Caterina Lupini, Claudia Maria Tucciarone, Giovanni Franzo, Valerio Giaccone, Sara Pedrazzoli, Giulia Quaglia, Giulia Graziosi, Marco De Nardi, Elena Catelli, Mattia Cecchinato","doi":"10.1080/03079457.2025.2557881","DOIUrl":"10.1080/03079457.2025.2557881","url":null,"abstract":"<p><strong>Research highlights: </strong>North-Western European reassortants (A3B1) were found in Italy for the first time.Local A3B1 clade, related to Russian and Middle Eastern strains, also persisted.Infectious pressure was seemingly stable despite this epidemiological shift.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"1-8"},"PeriodicalIF":2.2,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145022718","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":"Molecular detection of a novel herpesvirus in the stone-curlew (<i>Burhinus oedicnemus</i>) from the Canary Islands.","authors":"Ana Colom-Rivero, Antonio Fernández, Lucía Marrero-Ponce, Ayoze Castro-Alonso, Candela Rivero-Herrera, Lucía Caballero-Hernández, Cristian M Suárez-Santana, Eva Sierra","doi":"10.1080/03079457.2025.2489547","DOIUrl":"10.1080/03079457.2025.2489547","url":null,"abstract":"<p><p>Avian herpesviruses (AHVs) are widely distributed and associated with a variety of diseases affecting bird populations globally. Despite the increasing detection of AHVs in recent years, there remains a significant gap in knowledge regarding their classification and host range. This study aimed to detect herpesvirus (HV) in two vulnerable, endemic subspecies of stone-curlew (<i>Burhinus oedicnemus</i>) in the Canary Islands. Forty-six pooled tissue swabs (liver, kidney, and lung) and 135 individual swabs (brain, cloaca, and oropharyngeal cavity) were collected from 50 stone-curlews recorded as deceased wildlife specimens between 2020 and 2023. DNA from a novel alpha-HV was successfully amplified from seven out of the 181 tissue samples (4%) and from four out of 50 birds analysed (8%) using a semi-nested polymerase chain reaction (PCR) approach with degenerate primers. Positive samples were distributed across various tissue types: brain (<i>n</i> = 1), kidney (<i>n</i> = 1), lung (<i>n</i> = 2), coelomic cavity (<i>n</i> = 1), and oropharyngeal swab (<i>n</i> = 2). Some individuals tested positive in multiple tissue types, although no histopathological features indicative of HV infection were observed in any of the birds. Sequencing of all positive samples revealed identical HV nucleotide sequences across all specimens. The longest PCR amplicon, obtained with the TGV and KG1 primer combination, yielded identical sequences in two of the seven positive samples. Based on these findings, we propose the designation of this novel HV as <i>Burhinus oedicnemus alphaherpesvirus</i>.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"613-623"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143778791","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":"Differences in lesion development of slow- and fast-growing meat-type chickens after experimental challenge with <i>Enterococcus cecorum</i>.","authors":"Amanda Rosenbaum, Silke Rautenschlein, Arne Jung","doi":"10.1080/03079457.2025.2485109","DOIUrl":"10.1080/03079457.2025.2485109","url":null,"abstract":"<p><p>Field observations suggest genotype-associated differences in susceptibility to infection with <i>Enterococcus cecorum</i> (EC). We hypothesized that slow-growing (SG) chickens show less clinical signs and reduced lesions compared to fast-growing (FG) chickens after experimental challenge with EC. At 1-day post-hatch (dph), 97 FG and 97 SG chickens were randomly assigned to four groups: control, SG (CSG), control, FG (CFG), EC-inoculated, SG (ESG), and EC-inoculated, FG (EFG). After oral inoculation with 10⁷ colony forming units EC or mock inoculation with physiological saline, chickens were monitored for clinical signs and samples were collected weekly for further analysis via ELISA, real-time PCR, and flow cytometric analysis. The final necropsy of 40 chickens per group was carried out at 43/44 dph. Clinical signs and pathological findings were observed in a reduced number of chickens in group ESG compared to EFG. Extra-intestinal colonization with EC at 43/44 dph was significantly reduced in group ESG compared to EFG (<i>P</i> < 0.05). Circulating heterophils and monocytes were significantly increased in groups ESG and EFG compared to the control groups (<i>P</i> < 0.05). Additionally, circulating monocytes were increased and heterophil/lymphocyte (H/L) ratios were decreased in SG chickens compared to FG chickens. We may speculate that SG chickens were less affected by the EC-associated disease due to a more efficient innate immune response and may more vigorously control extra-intestinal colonization after translocation from the intestine. Overall, the use of slow-growing chickens may reduce the incidence of the EC-associated disease in meat-type chickens and therefore increase overall health performance.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"592-601"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143960064","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":"Molecular characterization and recombination analysis of <i>Gyrovirus homsa2</i> in chickens.","authors":"Zhibin Zhang, Weichi Li, Xin Xu, Dandan Li, Jun Ji, Lunguang Yao, Yingzuo Bi, Qingmei Xie","doi":"10.1080/03079457.2025.2494756","DOIUrl":"10.1080/03079457.2025.2494756","url":null,"abstract":"<p><p><i>Gyrovirus homsa2</i> (GyVh2), originally identified in Tunisian children with diarrhoea, was previously known as Gyrovirus 6. In this study, chickens from 36 poultry farms across four major poultry-producing provinces in China (Henan, Hubei, Anhui, and Jiangsu) were screened for GyVh2 using polymerase chain reaction (PCR) from 2022-2024. As a result, 12 farms positive for GyVh2 were detected and subsequently subjected to whole-genome sequencing for GyVh2. The genomes of the 12 GyVh2 from positive farms were all 2282 nucleotides (nt) in length. Sequence similarity analysis showed high similarity (94.87%-99.65%) among the obtained and reference GyVh2 strains with no significant determining effect of years or geographic distribution, but low similarity (48.99%-57.60%) with other Gyrovirus species (<i>Gyrovirus chickenanemia</i>, <i>Gyrovirus galga1</i>, <i>Gyrovirus galga2</i> and <i>Gyrovirus homsa1</i>). Phylogenetic analysis of the whole genome sequences of all 12 GyVh2-positive farms revealed that they formed a unique branch, clearly separated from other Gyrovirus species. Recombination analysis suggested that HN220604 (accession no.: PQ519595.1) and HN221228 (accession no.: PQ519596.1) may have originated from recombination with the human-derived GyVh2 strain (accession no.: NC_022789.1). A hypervariable region (located at sites 140-152) and highly mutated sites at positions 149, 254 and 380 were identified in the capsid protein through amino acid mutation analysis. The observed association between GyVh2 cross-species transmission and complex mutations and recombination offers a basis for future studies on its molecular epidemiology and evolution.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"624-632"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143969079","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":"Mechanism of pulmonary arterial vascular cell dysfunction in pulmonary hypertension in broiler chickens.","authors":"Juan Chen, Chenxi Jiang, Xiaoqin Hu, Yun Zhang, Xiaona Gao, Xiaoquan Guo, Huibo Jin, Ying Zhang, Yirong Wu, Jing Liang, Pei Liu, Ping Liu","doi":"10.1080/03079457.2025.2480802","DOIUrl":"10.1080/03079457.2025.2480802","url":null,"abstract":"<p><p>Broiler ascites syndrome is a common and complex disease in broiler farming, which severely impacts broiler growth performance and health and brings huge economic losses to the breeding industry. Hypoxia has been shown to be an important cause of this disease. Prolonged exposure of broiler chickens to a hypoxic environment induces pulmonary vasoconstriction, which leads to an increase in pulmonary artery pressure, triggering pulmonary artery remodelling and compensatory right ventricular hypertrophy, and ultimately ascites. Pulmonary artery remodelling is a process in which the vascular wall tissue structure and function undergo pathological changes after the pulmonary artery is stimulated by various injuries or hypoxia, including endothelial dysfunction, abnormal proliferation of pulmonary artery smooth muscle cells, vascular fibrosis, etc. When these cells are damaged or stimulated, they may undergo programmed cell death, an orderly and regulated mode of cell death that is important for maintaining the stability of the body's internal environment. It has been demonstrated that death modes such as apoptosis and autophagy are involved in the pathophysiologic process of pulmonary hypertension, but their specific molecular mechanisms are still unclear. In this review, we first describe the pathogenesis of broiler ascites, then describe the specific mechanism of dysfunction of pulmonary artery vascular cells in broiler ascites syndrome, and finally elaborate the progression of different programmed cell death in broiler pulmonary hypertension. This study aims to elucidate the specific mechanisms underlying the dysfunction of pulmonary artery vascular cells in broiler pulmonary hypertension, thereby enhancing our understanding of the pathogenesis of this syndrome.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"548-559"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143969333","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":"10.1080/03079457.2025.2485106","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Birds harbour &lt;i&gt;Enterococcus faecium&lt;/i&gt; and &lt;i&gt;Enterococcus faecalis&lt;/i&gt; as gut commensals but could acquire and transmit high-priority strains. Following the PRISMA guidelines, eligible studies that reported the antimicrobial resistance (AMR) profiles of &lt;i&gt;E. faecium&lt;/i&gt; and &lt;i&gt;E. faecalis&lt;/i&gt; from gut samples of food-producing (FPBs) and wild birds (WBs) published from 2005-2024 were screened from major bibliographic databases. Random-effect models were used to determine the pooled prevalences (PPs) of vancomycin (VAN&lt;sup&gt;R&lt;/sup&gt;), ampicillin (AMP&lt;sup&gt;R&lt;/sup&gt;), and linezolid (LZD&lt;sup&gt;R&lt;/sup&gt;) resistant &lt;i&gt;E. faecium&lt;/i&gt; and &lt;i&gt;E. faecalis&lt;/i&gt; from non-duplicated gut samples of FPBs and WBs. Of the 36 eligible studies, the overall PP of VAN&lt;sup&gt;R&lt;/sup&gt;-&lt;i&gt;E. faecium&lt;/i&gt; and VAN&lt;sup&gt;R&lt;/sup&gt;-&lt;i&gt;E. faecalis&lt;/i&gt; were 1.8% and 0.7%, respectively. AMP&lt;sup&gt;R&lt;/sup&gt;-&lt;i&gt;E. faecium&lt;/i&gt; and AMP&lt;sup&gt;R&lt;/sup&gt;-&lt;i&gt;E. faecalis&lt;/i&gt; were 1.6% and 0.6%, respectively. LZD&lt;sup&gt;R&lt;/sup&gt;-&lt;i&gt;E. faecium&lt;/i&gt; and LZD&lt;sup&gt;R&lt;/sup&gt;-&lt;i&gt;E. faecalis&lt;/i&gt; were 1% and 0.8%, respectively. Subgroup analyses revealed significant temporal variations in the PPs of VAN&lt;sup&gt;R&lt;/sup&gt;-&lt;i&gt;E. faecium&lt;/i&gt; (&lt;i&gt;P&lt;/i&gt; &lt; 0.05). FPBs had significantly higher PPs of VAN&lt;sup&gt;R&lt;/sup&gt;, AMP&lt;sup&gt;R&lt;/sup&gt; and LZD&lt;sup&gt;R&lt;/sup&gt; &lt;i&gt;E. faecium&lt;/i&gt; and &lt;i&gt;E. faecalis&lt;/i&gt; than WBs (&lt;i&gt;P&lt;/i&gt; &lt; 0.05). Healthcare-associated &lt;i&gt;vanA&lt;/i&gt;-carrying &lt;i&gt;E. faecium&lt;/i&gt; lineages from WBs (ST16, ST17, ST18, and ST412) and &lt;i&gt;optrA&lt;/i&gt;-carrying &lt;i&gt;E. faecalis&lt;/i&gt; lineages (ST32, ST59, ST330) from FPBs were identified. In FPBs, Egypt had the highest PP of VAN&lt;sup&gt;R&lt;/sup&gt;-&lt;i&gt;E. faecium&lt;/i&gt; (11.9%) and LZD&lt;sup&gt;R&lt;/sup&gt;-&lt;i&gt;E. faecalis&lt;/i&gt; (2.8%). Conversely, the USA had the highest PP of VAN&lt;sup&gt;R&lt;/sup&gt;-&lt;i&gt;E. faecium&lt;/i&gt; in WBs (2.4%). A higher frequency of vancomycin- than linezolid-resistant strains exists, and VAN&lt;sup&gt;R&lt;/sup&gt;-&lt;i&gt;E. faecium&lt;/i&gt; are disproportionately distributed based on bird species, year of study, and country, indicating varied selection pressure. Significantly higher prevalence of VAN&lt;sup&gt;R&lt;/sup&gt;-&lt;i&gt;E. faecium&lt;/i&gt; than VAN&lt;sup&gt;R&lt;/sup&gt;-&lt;i&gt;E. faecalis&lt;/i&gt; was found, highlighting the higher capacity of &lt;i&gt;E. faecium&lt;/i&gt; to acquire ampicillin and vancomycin resistance in birds.&lt;b&gt;RESEARCH HIGHLIGHTS&lt;/b&gt; Vancomycin, ampicillin, and linezolid resistance in &lt;i&gt;E. faecium&lt;/i&gt; and &lt;i&gt;E. faecalis&lt;/i&gt; are considered high-priority public health concerns.This is a meta-analysis of high-priority &lt;i&gt;E. faecium&lt;/i&gt; and &lt;i&gt;E. faecalis&lt;/i&gt; from gut samples of birds.Food-producing birds had significantly higher frequency of priority &lt;i&gt;E. faecium&lt;/i&gt; and &lt;i&gt;E. faecalis&lt;/i&gt; than wild birds.Vancomycin resistance in &lt;i&gt;E. faecium&lt;/i&gt; and &lt;i&gt;E. faecalis&lt;/i&gt; exists more frequently than linezolid resistance.&lt;i&gt;E. faecium&lt;/i&gt; has a higher capacity to acquire ampicillin and vancomycin resistance than &lt;i&gt;E. faecalis&lt;/i&gt;.Genetically related human-adapted vancomycin- and linezolid-resistant strains were identified in food-producing ","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"577-591"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","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":"Establishment and application of an indirect enzyme-linked immunosorbent assay based on tandem expression PrgH-PagN protein to detect <i>Salmonella</i> infection in ducks.","authors":"Changxu Yu, Fahui Song, Shuyang Wang, Jikun Wu, Luyang Zhou, Shuo Yang, Aofei Wang, Shuqi Wei, Ruihua Zhang, Shijin Jiang, Yanli Zhu","doi":"10.1080/03079457.2025.2487524","DOIUrl":"10.1080/03079457.2025.2487524","url":null,"abstract":"<p><p><i>Salmonella,</i> an important foodborne zoonotic pathogen, can be transmitted both vertically and horizontally. It is difficult to control and effectively decontaminate <i>Salmonella</i>, and it poses a serious threat to food safety. Therefore, to prevent the spread of salmonellosis, there is an urgent need for a rapid, accurate and sensitive assay to detect the prevalence of <i>Salmonella</i> in duck flocks. In this study, we utilized biological software to predictively screen the highly conserved <i>Salmonella</i>-specific proteins SpiC, PrgH and PagN. The recombinant proteins PrgH, SpiC, PagN were screened for sensitivity based on individual proteins and pairwise combinations (SpiC + PrgH, SpiC + PagN and PrgH + PagN). A specific and sensitive dual-protein combination, PrgH + PagN, was used as an antigen. Subsequently, PrgH-PagN was produced by tandem expression and employed as the coating antigen in an indirect ELISA (iELISA) for detecting <i>Salmonella</i> antibodies in duck serum. The optimal antigen coating concentration was determined to be 1 μg/ml, with a critical value of OD₄₅₀ = 0.154. The cross-reactivity test results showed no evidence of cross-reactivity with known positive serums from ducks infected with <i>S</i>. Enteritidis, <i>S.</i> Typhimurium, <i>S</i>. Kottbus, <i>E. coli</i>, <i>Streptococcus</i> or <i>Staphylococcus</i>. Screening of 611 duck serums was performed to determine an overall positive rate of 22.09%. The final compliance rate of 93.1% was determined by comparison with that of the commercial kit. In conclusion, the PrgH-PagN-iELISA established in the present study was an accurate and reliable method, with high sensitivity and specificity for detecting antibody responses to systemic <i>Salmonella</i> infections in ducks.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"602-612"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144118678","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 auto-bioluminescent <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":"10.1080/03079457.2025.2477246","url":null,"abstract":"<p><p>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. The 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 allowed precise monitoring of infection progression without sequential culling. This offers a controlled platform for evaluating antimicrobial treatment efficacy in an <i>in ovo</i> model that closely resembles an <i>in vivo</i> chicken model. It can also be used to study infection patterns of other pathogens, especially those that pose risks to public health.<b>RESEARCH HIGHLIGHTS</b>Bioluminescence imaging enabled real-time, noninvasive tracking of a bioluminescent APEC infection in embryonated chicken eggs over time.Bioluminescence signals showed contrasting patterns for dead and surviving embryos.The <i>ilux2</i>-APEC showed a higher luminoscore than <i>lux</i>ABCDE-APEC in inoculated embryonated chicken eggs.The <i>in ovo</i> bioluminescent signal from intact eggs effectively reflects the <i>ex ovo</i> signal following the take out of yolk and embryo.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"560-569"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","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":"An outbreak in week-old broiler chicks caused by a highly virulent and multidrug-resistant strain of <i>Salmonella</i> Gallinarum.","authors":"Eric Santos Oliveira, Letícia Cury Rocha Veloso Arantes, Gabryel Bernardo Vieira de Lima, Victória Veiga Alves, Michelle de Paula Gabardo, Bertram Brenig, Vasco Azevedo, Flávia Figueira Aburjaile, Oliveiro Caetano de Freitas Neto, Roselene Ecco","doi":"10.1080/03079457.2025.2480800","DOIUrl":"10.1080/03079457.2025.2480800","url":null,"abstract":"<p><p><i>Salmonella</i> Gallinarum is a bacterium that causes significant economic losses in poultry farming and usually infects adult birds. This study aimed to characterize the unusual histological findings and genetic profile of a <i>Salmonella</i> Gallinarum (SG) strain isolated from a natural outbreak that affected 1500 broiler chicks in their first week of life. To confirm the diagnosis, necropsy, histopathology, and immunohistochemistry were performed on 19 chicks, with bacterial isolation in two of them, followed by confirmation through PCR, genetic sequencing, and genomic analysis. The outbreak revealed unusual gross and histological lesions: in the intestines, there was macroscopic haemorrhage of varying severity and, microscopically, the lesions were characterized by histiocytic and heterophilic transmural typhlitis; in the lungs, there was histiocytic interstitial pneumonia of varying intensities. Additional lesions included splenitis, myocarditis, and hepatitis. <i>Salmonella</i> was <i>in situ</i>-labelled in all mentioned organs using immunohistochemistry. Following the virulome and resistome analysis, which compared the genetic profile of the isolate with a reference SG genome, it was found that the isolate from this outbreak contained 36 exclusive virulence genes and six exclusive antimicrobial resistance genes. These genetic alterations may explain the severe systemic lesions observed in these chicks.<b>RESEARCH HIGHLIGHTS</b><i>Salmonella</i> Gallinarum infection in chicks resulted in a mortality rate of 42%.Chicks had unusual lesions such as haemorrhagic enteritis and interstitial pneumonia.Whole genome analysis of the SG isolate revealed exclusive antimicrobial resistance genes.Higher number of exclusive virulence genes were related to severe fowl typhoid in chicks.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":" ","pages":"570-576"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143647056","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}