Karakteristik Molekuler Gen Hemaglutinin Avian Influenza H9N2 Pasca Penghambatan Infeksi oleh Sialidase Asal Pasteurella multocida secara In Ovo

Abstract

Pencegahan dan pengobatan virus pada saluran pernapasan telah banyak digunakan, salah satuya adalah sialidase. Sialidase asal bakteri Pasteurella multocida telah terbukti efektif menekan infeksi virus H9N2. Namun, perlu dilakukan penelitian lebih lanjut terkait efek yang akan terjadi pada virus apabila terus diberikan sialidase. Pada proses interaksi virus dan inang, virus dapat melarikan diri dengan merubah susunan asam amino pada gen hemaglutinin. Protein HA1 merupakan situs utama yang mengalami antigenic drift karena besarnya jumlah epitop. Penelitian ini bertujuan menganalisis karakteristik molekuler gen hemaglutinin avian influenza H9N2 pasca penghambatan oleh sialidase asal bakteri Pasteurella multocida. Penelitian ini menggunakan isolat dengan nama A/Layer/Indonesia/WestJava-04/2017. Konfirmasi virus dilakukan menggunakan reverse transcription polymerase chain reaction. Setelah itu, dilakukan pasase sebanyak lima kali pada kelompok placebo dan kelompok sialidase. Gen hemaglutinin disekuensing menggunakan metode sanger dan dianalisis pada receptor binding pocket, homologi, dan filogenetik. Hasil penelitian ini menunjukan seluruh kelompok tidak mengalami perubahan pada gen HA setelah lima pasase. Perbandingan homologi menunjukan 100% serupa dengan virus awal. Pohon filogenik menunjukan ada keterkaitan pada isolat A/muscovy_duck /Vietnam/LBM719/2014 dan A/chicken/Henan/LY-36/2013.

The prevention and treatment of viruses in the respiratory tract have been widely used, including sialidase. Sialidase from the bacterium Pasteurella multocida has been shown to be effective in suppressing H9N2 virus infection. However, further research is needed regarding the effect that will occur on the virus if sialidase is continued. During the interaction between the virus and the host, the virus can escape by changing the amino acid sequence in the hemagglutinin gene. The HA1 protein is the main site that experiences antigenic drift due to a large number of epitopes. This study aims to analyze the molecular characteristics of the avian influenza H9N2 hemagglutinin gene after inhibition by sialidase from the bacterium Pasteurella multocida. This study used isolates with the name A/Layer/Indonesia/WestJava-04/2017. Virus confirmation was performed using reverse transcription polymerase chain reaction. After that, five passages were performed in the placebo and sialidase groups. The hemagglutinin gene was sequenced using the Sanger method and analyzed for receptor binding pocket, homology, and phylogenetics. The results of this study showed that all groups did not experience changes in the hemagglutinin gene after five passages. Homology comparisons show 100% similarity to the original virus. The phylogenic tree shows that there is a relationship between A/muscovy_duck/Vietnam/LBM719/2014 and A/chicken/Henan/LY-36/2013 isolates.