Avian diseases最新文献

{"title":"Antiviral Effect of Different Essential Oils on Avian Coronavirus.","authors":"Cintia Hiromi Okino, Gláucia Roberta Melito, Maria Eduarda de Almeida Astolfo, Maria Eduarda Da Mata Martins, Stanislau Bogusz Junior, Marcos David Ferreira","doi":"10.1637/aviandiseases-D-24-00015","DOIUrl":"10.1637/aviandiseases-D-24-00015","url":null,"abstract":"<p><p>Plant essential oils (EOs) possess established antimicrobial properties; however, research on their antiviral activity, particularly against avian coronaviruses, remains limited. EOs offer a promising plant-based alternative for viral control, especially in scenarios where conventional chemical use is restricted. This study aimed to evaluate the antiviral effects of six different essential oils derived from <i>Syzygium aromaticum</i>, <i>Origanum vulgare</i>, <i>Cymbopogon martinii</i>, <i>Cymbopogon citratus</i>, <i>Mentha piperita</i>, and <i>Mentha spicata</i> against avian coronavirus (AvCov) at 0.1% and 1% dilutions. The antiviral effects of the EOs were assessed via virus isolation from embryonated chicken eggs, and the ability of the EOs to inhibit AvCoV replication was evaluated. The EOs from <i>Syzygium aromaticum</i>, <i>Origanum vulgare</i>, <i>Cymbopogon martinii</i>, and <i>Cymbopogon citratus</i> completely inhibited AvCov replication at a 1% dilution. Conversely, absent to partial inhibitory effect was observed at the 0.1% dilution for all tested EOs, with <i>O. vulgare</i> derived EO exhibiting the greatest inhibitory effect (over 70%). Notably, EOs from <i>Mentha piperita</i> and <i>Mentha spicata</i> were unable to completely inhibit AvCov at either concentration. Our findings highlight the potent antiviral activity of the EOs from <i>Syzygium aromaticum</i>, <i>Origanum vulgare</i>, <i>Cymbopogon martinii</i>, and <i>Cymbopogon citratus</i> against AvCov at a 1% dilution. The complete inhibition observed for these EOs suggests their potential for AvCov control. However, further research is necessary to elucidate the mechanisms of action, optimize formulations, and evaluate the efficacy against other coronaviruses, including those relevant to human health.</p>","PeriodicalId":516846,"journal":{"name":"Avian diseases","volume":"68 3","pages":"254-258"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142485237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gizzard Erosion and Ulceration Syndrome in Moroccan Poultry Flocks and Molecular Characterization of Fowl Adenoviruses (FAdV).","authors":"Ikram Ouchhour, Siham Fellahi, Oumayma Arbani, Mourad Mastour, Ahmed Achehal El Kadmiri, Mohamed Mouahid, Amina Kardoudi, Abdelouaheb Benani, Abdelmounaim Allaoui, Faouzi Kichou","doi":"10.1637/aviandiseases-D-24-00004","DOIUrl":"10.1637/aviandiseases-D-24-00004","url":null,"abstract":"<p><p>Gizzard erosion and ulceration syndrome (GEUS) is caused by a fowl adenovirus serotype 1 (FAdV-1) and was first reported in laying hens in Japan in 1993. This syndrome has emerged as an epizootic in Morocco since 2014, causing significant economic losses for the poultry industry, but no involvement of a FAdV has been confirmed. Thus, the objective of this work was to assess GEUS cases that occurred in the country and to determine the role of FAdVs in their occurrence. Investigations were based on a retrospective reassessment of tissue sections and paraffin blocks of gizzards and livers from GEUS cases between 2014 and 2021 coupled with a prospective search of cases in 2022. Gizzards and livers were fixed in 10% neutral buffered formalin for histopathologic examinations according to standard methods and stored at -20 C for molecular analysis. After deparaffinizing, 10-µm-thick tissue sections along with fresh organs were subjected to DNA extraction using a commercial kit. A primer pair specific for the Hexon gene of FAdVs was used in conventional PCR; in contrast, for real-time PCR, a primer pair targeting the 52K gene was employed. In total, 24 flock cases with characteristic GEUS were assessed between 2014 and 2022. They were nine broiler cases aged between 11 and 39 days, 11 layer cases with an age between 17 and 29 wk, two cases in meat-type breeders aged 10 and 27 wk, and two flock cases of turkey poults aged 22 and 23 days. In most cases, microscopic lesions were consistent with an ulcerative and lymphoplasmocytic ventriculitis, and pathognomonic viral intranuclear inclusion bodies within degenerate epithelial cells were identified in four broiler flock cases, four layer cases, and one case in breeders and hence were highly suggestive of a FAdV infection. Among these nine cases that were positive at the histopathologic examination, six cases were found to be FAdV-PCR positive; another four cases were negative to histology but FAdV-PCR positive. Furthermore, a sequencing analysis was conducted, providing the initial evidence of the implication of FAdV-1 from species A as the cause of GEUS in Moroccan poultry. Additionally, a phylogenetic analysis was executed to facilitate a comparison between the strains investigated in this study and those identified in diverse geographic regions and across various time periods.</p>","PeriodicalId":516846,"journal":{"name":"Avian diseases","volume":"68 3","pages":"217-224"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142485245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficacy of Recombinant Marek's Disease Virus Vaccine 301B/1 Expressing Membrane-Anchored Chicken Interleukin-15.","authors":"Taejoong Kim, Cari Hearn, Mohammad Heidari","doi":"10.1637/aviandiseases-D-23-00068","DOIUrl":"10.1637/aviandiseases-D-23-00068","url":null,"abstract":"<p><p>Cytokines are co-administrated with vaccines or co-expressed in the vaccine virus genome to improve protective efficacy by stimulating immune responses. Using glycosylphosphatidylinositol (GPI) anchoring by attachment to the target cytokine, we constructed recombinant Marek's disease virus (MDV) vaccine strain 301B/1 (v301B/1-rtg-IL-15) that expresses chicken interleukin-15 (IL-15) as the membrane-bound form at the cell surface. We evaluated the vaccine efficacy of v301B/1-rtg-IL-15 given as a bivalent Marek's disease (MD) vaccine in combination with turkey herpesvirus (HVT) against a very virulent plus MDV strain 648A challenge. The efficacy was compared with that of conventional bivalent MD vaccine, as a mixture with HVT plus parental v301B/1 or v301B/1-IL-15, which expresses a natural form of IL-15. The membrane-bound IL-15 expression did not interfere with the virus growth of recombinant v301B/1-rtg-IL-15. However, the MD incidence in birds vaccinated with v301B/1-rtg-IL-15 was higher than that of birds given the conventional bivalent MD vaccine containing parental v301B/1 virus, although the v301B/1-rtg-IL-15 vaccinated group showed increased natural killer cell activation at day 5 postvaccination, the same day as challenge. Overall, the protection of v301B/1-rtg-IL-15 was not improved from that of v301B/1 against very virulent plus MDV challenge.</p>","PeriodicalId":516846,"journal":{"name":"Avian diseases","volume":"68 2","pages":"117-128"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141422408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic Sequence and Pathogenicity of Infectious Bursal Disease Virus in Chickens in Egypt During 2017-2021.","authors":"Ahmed R Elbestawy, Hatem S Abd El-Hamid, Hany F Ellakany, Ahmed R Gado, Shady H El-Rayes, Ahmed H Salaheldin","doi":"10.1637/aviandiseases-D-23-00087","DOIUrl":"10.1637/aviandiseases-D-23-00087","url":null,"abstract":"<p><p>The continued circulation of infectious bursal disease virus (IBDV) in Egypt, despite the use of various vaccines, is a serious problem that requires continuous detection of IBDV. In the current study, real-time reverse transcriptase polymerase chain reaction testing of 100 diseased chicken flocks during 2017-2021 revealed the presence of very virulent IBDV (vvIBDV) in 67% of the flocks, non-vvIBDV in 11%, and a mixture of both vvIBDV and non-vvIBDV in 4%. Twenty-nine IBDV isolates were submitted for partial sequencing of the viral protein 2 hypervariable region (VP2-HVR), and 27 isolates were confirmed to be genogroup A3 (vvIBDV) with 96.3%-98.5% similarity to the global A3 (vvIBDV) and 88.9%-97% similarity to genogroup A1 vaccine strains. The remaining two isolates were non-vvIBDV and showed 91.1% and 100% identity with classical genogroup A1 strains, respectively. Furthermore, the sequence and phylogenetic analysis of VP1 (amino acids 33-254) of two selected isolates of A3, 5/2017 and 98/2021, clustered them as B2, vvIBDV-like, strains with high similarity (99.5%) to four Egyptian, 99% to Chinese and European, and 97.7% to Chinese and Polish vvIBDV isolates. Experimental infection of commercial broiler chickens with two vvIBDV-A3B2 isolates (5/2017 and 98/2021) showed no mortality despite typical tissue lesions, clear histopathological changes, and strong ELISA antibody response. Isolate 98/2021 was more pathogenic, as confirmed by histopathology, whereas isolate 5/2017 induced a stronger serological response. In conclusion, vvIBDV (A3B2) strains with two amino acid (aa) substitutions in VP1 as V141I and V234I as well as VP2 as Y220F and G254S are still circulating in Egypt.</p>","PeriodicalId":516846,"journal":{"name":"Avian diseases","volume":"68 2","pages":"99-111"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141422409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and Evaluation of <i>Mycoplasma gallisepticum</i> Challenge Model in Layer Pullets.","authors":"Amro Hashish, Lauren McKeen, Yuko Sato, Mohamed El-Gazzar","doi":"10.1637/aviandiseases-D-23-00045","DOIUrl":"10.1637/aviandiseases-D-23-00045","url":null,"abstract":"<p><p>Manufacturers of <i>Mycoplasma gallisepticum</i> (MG) modified live vaccines usually recommend a single application at 8 wk of age. This makes 12-16-wk-old layer pullets suitable for challenge studies intended to evaluate these vaccines. Numerous challenge models in different poultry species and ages have been reported. However, there is not an established layer pullet challenge model for this age. The aim of this study is to develop a suitable challenge model in 12-wk-old layer pullets. MG R_low strain was used as the challenge strain, and its ability to induce clinical signs and lesions in 12-wk-old Hy-Line W-36 layer pullets was evaluated. Three different doses (low, 7.95 × 10⁴ color-changing units [CCU]/bird; medium, 7.95 × 10⁶ CCU/bird; and high, 7.95 × 10⁸ CCU/bird) via three different routes (eye drop, fine spray, and contact infection) were compared and evaluated using different parameters. At 14 days post-challenge, there were no mortalities in any of the groups throughout the study. Layer pullets directly challenged with the high dose via the fine spray route showed the clearest and most consistent results (clinical signs, positive quantitative real-time PCR [qPCR], seroconversion, air sac scoring, and histopathological changes of the tracheal mucosa). Medium and low challenge doses applied via fine spray or eye drop did not show consistent results. R_low strain was able to spread to the contact infection birds, as confirmed by the positive qPCR results; however, none of the contact-infected birds showed any clinical signs or gross or microscopic lesions. Our results suggest that a high dose (7.95 × 10⁸ CCU/bird) administered through a fine spray route is the model of choice in any future MG vaccine evaluation trials in 12-wk-old layer pullets.</p>","PeriodicalId":516846,"journal":{"name":"Avian diseases","volume":"68 2","pages":"145-155"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141422407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Internal Organ Colonization by <i>Salmonella</i> Enteritidis in Layer Pullets Infected at Two Different Ages During Rearing in Cage-Free Housing.","authors":"Richard K Gast, Deana R Jones, Rupa Guraya, Javier S Garcia, Darrin M Karcher","doi":"10.1637/aviandiseases-D-23-00081","DOIUrl":"10.1637/aviandiseases-D-23-00081","url":null,"abstract":"<p><p>The poultry-housing environment plays a significant role in the transmission and persistence of the egg-associated pathogen <i>Salmonella</i> Enteritidis in laying flocks. The commercial egg industry is in the midst of a transition toward cage-free housing, but the food safety ramifications of this shift are not yet certain. The present study assessed internal organ colonization by <i>Salmonella</i> Enteritidis in layer pullets reared in cage-free housing and infected at two different ages. Groups of 280 pullets were transferred from the rearing facility (at 9 wk of age in one trial and 15 wk in another) to a containment facility with four isolation rooms simulating commercial cage-free barns with perches and nest boxes (70 birds/room). Twenty-four pullets in each room were orally inoculated with <i>Salmonella</i> Enteritidis immediately after placement in the containment facility. At 1-2 wk postinoculation in each trial, samples of liver, spleen, and intestinal tract were collected from all birds in two rooms for bacteriologic culturing to detect <i>Salmonella</i> Enteritidis. At 21-22 wk of age, samples of spleen, ovary, and intestinal tract were similarly collected and tested from all birds in the remaining two rooms. Among samples collected at 1-2 wk postinoculation, <i>Salmonella</i> Enteritidis was isolated significantly more often from groups of pullets infected initially at 15 wk of age than from those infected at 9 wk (61% <i>vs</i>. 38% of livers, 59% <i>vs</i>. 31% of spleens, and 84% <i>vs</i>. 57% of intestines). Among samples collected at 21-22 wk of age, the frequency of recovery of <i>Salmonella</i> Enteritidis was again significantly greater in birds infected at 15 wk of age than in those infected at 9 wk (16% <i>vs</i>. 6% of spleens, 9% <i>vs</i>. 1% of ovaries, and 26% <i>vs</i>. 10% of intestines). These data suggest that <i>Salmonella</i> Enteritidis infections introduced into flocks during the later stages of pullet rearing have greater potential to persist into the early phase of egg production.</p>","PeriodicalId":516846,"journal":{"name":"Avian diseases","volume":"68 2","pages":"141-144"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141422410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Protection Against Infectious Bronchitis Virus Vaccine Recombinants and Chicken-Selected Vaccine Subpopulations.","authors":"Camila Cuadrado, Cassandra Breedlove, Edzard van Santen, Kelly S Joiner, Vicky L van Santen, Haroldo Toro","doi":"10.1637/aviandiseases-D-23-00064","DOIUrl":"10.1637/aviandiseases-D-23-00064","url":null,"abstract":"<p><p>Outbreaks of infectious bronchitis (IB) continue to occur from novel variants of IB virus (IBV) emerging from selection of vaccine subpopulations and/or naturally occurring recombination events. S1 sequencing of Arkansas (Ark) -type viruses obtained from clinical cases in Alabama broilers and backyard chickens shows both Ark Delmarva Poultry Industry (ArkDPI) vaccine subpopulations as well as Ark vaccine viruses showing recombination with other IB vaccine viruses. IB Ark-type isolates AL5, most similar to an ArkDPI vaccine subpopulation selected in chickens, AL4, showing a cluster of three nonsynonymous changes from ArkDPI subpopulations selected in chickens, and AL9, showing recombination with Massachusetts (Mass) -type IBV, were examined for pathogenicity and ability to break through immunity elicited by vaccination with a commercial ArkDPI vaccine. Analysis of predicted S1 protein structures indicated the changes were in regions previously shown to comprise neutralizing epitopes. Thus, they were expected to contribute to immune escape and possibly virulence. Based on clinical signs, viral load, and histopathology, all three isolates caused disease in naïve chickens, although AL9 and AL5 viral loads in trachea were statistically significantly higher (30- and 40-fold) than AL4. S1 gene sequencing confirmed the stability of the relevant changes in the inoculated viruses in the chickens, although virus in some individual chickens exhibited additional S1 changes. A single amino acid deletion in the S1 NTD was identified in some individual chickens. The location of this deletion in the predicted structure of S1 suggested the possibility that it was a compensatory change for the reduced ability of AL4 to replicate in the trachea of naïve chickens. Chickens vaccinated with a commercial ArkDPI vaccine at day of hatch and challenged at 21 days of age showed that vaccination provided incomplete protection against challenge with these viruses. Moreover, based on viral RNA copy numbers in trachea, differences were detected in the ability of the vaccine to protect against these IBV isolates, with the vaccine protecting the most poorly against AL4. These results provide additional evidence supporting that IBV attenuated vaccines, especially ArkDPI vaccines, contribute to perpetuating the problem of IB in commercial chickens.</p>","PeriodicalId":516846,"journal":{"name":"Avian diseases","volume":"68 2","pages":"89-98"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141422412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Myotendinopathy of Unknown Etiology in Broiler Breeder Males.","authors":"Jason Sousa, Robin Gilbert, Frederic J Hoerr","doi":"10.1637/aviandiseases-D-23-00083","DOIUrl":"10.1637/aviandiseases-D-23-00083","url":null,"abstract":"<p><p>This case series describes an emerging and ongoing lameness condition observed in broiler breeder males in flocks owned by a broiler integrator in the United States between February 2021 and April 2023. The lameness is characterized by an upright, penguin-like posture and gait. Affected flocks are typically 12-22 wk of age at presentation, but birds with similar stance and gross lesions can be observed as early as 1 day of age. Male mortality associated with this condition ranges from 0.01% to 6% per flock. The condition is infrequently observed in pullets from the female line but has not been observed in males (sex slips) from the female line. On postmortem examination, affected birds have bilateral hemorrhage due to a tearing of the iliotibialis muscles and fascia. In one case, a higher proportion of affected birds had unilateral lesions concurrently with broken legs or severe inguinal vaccine reaction. In this case, the affected leg was the weight-bearing leg. Histopathology confirmed the presence of hemorrhage in fascial sheaths surrounding major muscles, in addition to muscle fiber necrosis, edema, fibroplasia, and dissociation of tendon collagen. Bacteriology, histopathology, and clinical presentation identified no factors that were suggestive of an infectious etiology for this condition. No etiology has been established, but a suggested pathogenesis involves excessive biomechanical force resulting in tendon structural stress, leading to separation of tendon collagen fibers and associated muscle fiber stretching, separation, necrosis, and hemorrhage. The condition has been reported in multiple genetic lines, but the role of inheritance in the condition has not been fully evaluated.</p>","PeriodicalId":516846,"journal":{"name":"Avian diseases","volume":"68 2","pages":"156-162"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141422411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Circulation and Molecular Characterization of Infectious Laryngotracheitis Virus in Poultry Flocks with Respiratory Disorders in Turkey, 2018-2022.","authors":"Inci Başak Müştak, Hamit Kaan Müştak","doi":"10.1637/aviandiseases-D-23-00074","DOIUrl":"10.1637/aviandiseases-D-23-00074","url":null,"abstract":"<p><p>Infectious laryngotracheitis (ILT) is a very serious worldwide respiratory disease of poultry, with many countries reporting ILT infections over the last decade. However, few reports are available regarding ILT disease prevalence in poultry in Turkey. Accordingly, the present study investigated ILT infection in Turkish broiler flocks between 2018 and 2022. Circulating ILT strains were characterized by sequence and phylogenetic analysis of two fragments of the infected-cell protein 4 gene. ILT virus (ILTV) was confirmed by quantitative PCR in 8 of the 21 flocks examined. As in other diseases, co-infections with other respiratory pathogens in confirmed ILT cases may worsen the symptoms and prolong the disease course. The present study confirmed co-infections with infectious bronchitis virus (13/21 tested flocks and 5/8 ILTV-positive flocks), indicating the importance of these pathogens in the occurrence of ILT infections.</p>","PeriodicalId":516846,"journal":{"name":"Avian diseases","volume":"68 2","pages":"112-116"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141422406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Yeast Expressing a Phage Endolysin Reduces Endogenous <i>Clostridium perfringens Ex Vivo</i> in 21-Day-Old Broiler Chicken Intestinal Fluids.","authors":"Michael R Barnas, Wendy D Attuquayefio, David M Donovan, Christopher D Skory, Rosemarie W Hammond, Gregory R Siragusa, Jennifer R Timmons","doi":"10.1637/aviandiseases-D-23-00088","DOIUrl":"10.1637/aviandiseases-D-23-00088","url":null,"abstract":"<p><p>The phage endolysin PlyCP41 when purified from <i>Escherichia coli</i> exhibits lytic activity against <i>Clostridium perfringens</i> (CP) <i>in vitro</i>. The anti-clostridial activity of PlyCP41 endolysin expressed in transgenic yeast (<i>Saccharomyces cerevisiae</i>) was verified in phosphate buffered saline via mixing experiments with cultured CP and transgenic yeast slurries followed by serial dilution plating and colony counts on tryptose sulfite cycloserine (CP indicator) plates. The transgenic yeast containing PlyCP41 resulted in a log₁₀ 4.5 reduction (99.997%; <i>P</i> < 0.01) of the cultured CP. In addition, this serial dilution plating assay was used to demonstrate that transgenic yeast slurries could reduce the endogenous CP content in fluids from three different gastrointestinal regions (proximal, medial, and distal) from 21-day-old broiler chickens. The transgenic yeast treatment of gut slurries resulted in a log ₁₀ 1.19, 4.53, and 1.28 reduction in proximal, medial, and distal gut slurries (90% to 99.99% of the endogenous CP; <i>P</i> < 0.01), respectively, compared to nontreatment controls. These results indicate that the phage endolysin PlyCP41 expressed in <i>S. cerevisiae</i> is effective at reducing the endogenous CP in gastrointestinal fluids of broiler chickens. Future studies will measure the anti-CP effect <i>in vivo</i> by administering transgenic yeast to broiler chickens in the feed.</p>","PeriodicalId":516846,"journal":{"name":"Avian diseases","volume":"68 2","pages":"129-133"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141422413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}