First report of Babesia occultans in two symptomatic cows in Iran.

This study reports the identification and first molecular characterization of Babesia occultans from naturally infected cows in Iran. Microscopic examination showed pyriform trophozoites, and ring-shaped merozoites (>2.5 μm) in Giemsa-stained blood smears obtained from two symptomatic cows in West-Azarbaijan province, Iran. PCR amplification of the partial 18S rRNA gene including the V4 hypervariable region were carried out on DNA extracted from blood samples. BLAST analyses of the partial 18S rRNA (approximately 400 bp) obtained from two cows revealed the presence of B. occultans and the detected sequences were identical to each other. Comparisons of the partial 18S rRNA sequence of the current isolate with other B. occultans sequences from Tunisia, South Africa, Turkey, Pakistan, and China confirmed the relation of the Iranian isolate to the species B. occultans. Sequence analysis of the obtained B. occultans showed 99.5-100% identity to the previously reported isolates. The sequences of B. occultans had 100% identity to a sequence obtained from ticks in Tunisia. This report is the beginning of a path to further research about B. occultans in vectors and reservoirs throughout Iran.