Acta Veterinaria et Zootechnica Sinica ›› 2025, Vol. 56 ›› Issue (12): 6316-6325.doi: 10.11843/j.issn.0366-6964.2025.12.034

• PREVENTIVE VETERINARY MEDICINE • Previous Articles     Next Articles

Establishment of Blood Nucleic Acid Screening Technology for Subgroup J/K Avian Leukosis Virus

WANG Hongmei1, ZHOU Wanyi1, LUO Xinjie1, CHEN Huilin1, CHEN Qinxi1, SHU Xueli1, ZHANG Jinyu1, SU Tong1, LIAO Ming3, CAO Weisheng1,2,3,4,5*   

  1. 1. College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China;
    2. Guangdong Provincial Key Laboratory of Prevention and Control for Animal Originated Zoonotic Diseases, Guangzhou 510642, China;
    3. National-Local Joint Engineering Laboratory for Zoonotic Disease Control and Prevention, Guangzhou 510642, China;
    4. Key Laboratory of Veterinary Vaccine Innovation of the Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China;
    5. Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China
  • Received:2025-03-18 Published:2025-12-24

Abstract: This study aimed to shorten the detection cycle for subgroup J/K avian leukosis virus (ALV-J/K) purification and accelerate the avian leukosis (AL) purification process, this study established a rapid blood nucleic acid screening technique (ALV-J/K blood quantitative polymerase chain reaction, ALV-J/K-B-qPCR) suitable for low-prevalence scenarios of ALV-J/K. By selecting conserved regions of ALV-J and K to design specific primers and TaqMan probes, and optimizing the reaction conditions, a TaqMan qPCR detection method for ALV-J/K was established. Using blood samples identified as ALV-J/K positive through cell culture virus isolation as experimental materials, anticoagulated whole blood DNA, blood cell DNA, and plasma cDNA were prepared and subjected to ALV-J/K TaqMan qPCR detection to identify the optimal detection template. Nucleic acids were extracted using a blood room-temperature lysis kit and a universal column-based genomic DNA extraction kit to screen for the optimal nucleic acid extraction method. The effect of varying dilution factors of positive samples on detection results was investigated to assess the feasibility of mixed sample detection. A simulated blood nucleic acid screening test with an expected prevalence rate of 1% to 2% was conducted using ALV-J/K-B-qPCR, and the results were compared with those obtained by the virus isolation method. The specificity, sensitivity, and repeatability tests of ALV-J/K TaqMan qPCR demonstrated that this method specifically amplifies only ALV-J and ALV-K, with detection limits of 8.95×101 copies·μL-1, 8.16×101 copies·μL-1 for positive standards, respectively. The sensitivity was 100 times higher than that of conventional PCR, and both intra- and inter-assay coefficients of variation <2%. The detection results of 96 clinical samples revealed that the ALV-J/K TaqMan qPCR had a detection rate of 21.9%, which was higher than that of conventional PCR (15.6%) and ALV p27 ELISA (18.8%). In the detection template screening test, anticoagulated whole blood DNA was identified as the optimal detection template. In the nucleic acid extraction method screening test, the universal column-based genomic DNA extraction kit yielded the best nucleic acid detection results. In the feasibility assessment test for mixed sample detection, the method established in this study was capable of detecting samples with low viral loads when the number of mixed samples <10. The simulated nucleic acid screening test for blood with an expected prevalence rate of 1% to 2% showed that the ALV-J/K-B-qPCR had a detection rate of 4%, which was 2.5% higher than that of the virus isolation method. The ALV-J/K-B-qPCR technology established in this study offers the advantages of simultaneous detection and differentiation of ALV-J and ALV-K, high sensitivity, strong specificity, high detection efficiency, and cost-effectiveness, aiming to provide a novel technique for AL purification in breeding poultry farms.

Key words: subgroup J avian leukosis virus, subgroup K avian leukosis virus, qPCR, nucleic acid screening, pooling sample assay

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