Colorimetric Pcr Assay for Rapid Detection Of  Marek's Disease Virus in Chicken

Marek’s disease is an oncogenic virus that produces malignant lymphomas in chickens. In this study, identification of Marek’s disease virus serotype 1 was done by using a colorimetric integrated polymerase chain reaction with Meq gene. The forward primer of the Meq gene which is specific to MDV serotype 1 was integrated with HRPzyme sequence (916bp) and amplified during the PCR. The PCR product including HRPzyme produced the distinguished blue colour with chromogenic substrates which was visualized by the naked eye. From these observations, rapid and easy detection of MDV serotype 1 was performed with satisfying sensitivity and specificity and no cross reaction was observed with other avian oncogenic viruses. This assay also compared with conventional PCR showed positive amplicon size at 856bp is specific for the Meq gene of MDV serotype 1. Phylogenetic analysis of MDV serotype 1 revealed that strains of IND/TN/MDV/1/2021 and IND/TN/MDV/2/2021 are grouped with high virulent strains of the USA. Screening of 430 field samples revealed 111 feather follicles, 24 liver, 23 spleens, 18 kidneys, and 6 sciatic nerves were showed positivity for MDV serotype 1 and it was further confirmed by the histopathological examination of various tissues of organs.