Abstract
Newcastle disease virus (NDV) remains an important threat to poultry health, while complete genome data from Kazakhstan remain limited. In this study, two NDV-positive samples obtained from domestic chicken carcasses in the Almaty region were propagated in embryonated chicken eggs and characterized by diagnostic PCR/RT-PCR, infectivity assessment, whole-genome sequencing, phylogenetic analysis, and comparative molecular analysis. Both isolates replicated efficiently in embryonated eggs, reaching 9.6–9.7 log 10 EID 50 /mL, with HA titers of 1:128–1:256 and no virus-attributable embryo mortality or marked embryo lesions. The complete consensus genomes of NDV_KZ_I and NDV_KZ_II were 15,186 bp and contained six major coding sequences arranged in the canonical 3′-N-P-M-F-HN-L-5′ order. Both isolates were closely related to the lentogenic vaccine-like strain AVIVAK-NDV-LaSota, and the F protein cleavage site motif was 112 GRQGRL 117 , consistent with a lentogenic molecular profile. The F and HN proteins were identical between the isolates, with conserved predicted N-linked glycosylation motifs and predicted linear B-cell epitope profiles. The complete genome sequences were submitted to GenBank under submission number SUB16299204. Because the vaccination history of the source birds was unavailable and ICPI/MDT assays were not performed, the isolates should be interpreted as vaccine-like NDV detected during diagnostic investigation rather than confirmed causative agents of mortality. These data expand available NDV genomic information from Kazakhstan and support future molecular surveillance.