Molecular Evidence of Hepatozoon felis Infection in Wild Captured Royal Bengal Tiger Cub (Panthera tigris tigris)

Background: Tigers are protected under schedule I of the Wildlife Protection Act, 1972. The current report highlights the detection of Hepatoozoon felis in a tiger cub. The infection is transmitted by ingestion of infected tick, infected prey and carrion. It is subclinical in adults; however, the cubs and immunocompromised adults may show clinical symptoms. Concurrent infection with bacterial or viral infections may be fatal to the infected animal. Methods: Hepatozoonosis was detected by blood smear examination using Giemsa staining. A PCR targeting the 18S ribosomal RNA was used to confirm the infection. The amplicon was purified and sequenced using a sanger sequencer. The 18S ribosomal RNA fragment sequence was compared to the available sequences in NCBI database using the nucleotide BLAST Tool. Neighbour joining phylogenetic trees using the bootstrap method were constructed using MEGA X software. Result: The presence of an intermediate gamont stage in neutrophils was seen under high resolution. The 660 bp amplicon was purified, sequenced and analysed for identity using the nucleotide BLAST tool of NCBI. The sequence was found to be 99.32%, similar to Hepatozoon felis. The phylogenetic analysis by neighbour joining phylogenetic tree using the bootstrap method indicated similarity with other reported sequences of H. felis isolated from Asian Lions. The sequence, however, was very dissimilar to the previously reported H. felis isolated from Royal Bengal Tiger. Considering the potential threat Hepatozoonosis can have in the wild, the prevalence must be estimated in prey base, sympatric cat species and arthropod vectors.