Conference Agenda

Haemocystidium spp. are apicomplexan parasites infecting reptiles, particularly freshwater turtles, yet their diversity and epidemiology remain poorly understood. This study aimed to detect and characterise Haemocystidium spp. in freshwater turtles from diverse populations in Australia. In total, 114 blood samples were collected from 8 turtle species. Blood smears were prepared from each turtle and examined by light microscopy, and genomic DNAs were isolated from matching blood samples using the DNeasy Blood & Tissue Kit (Qiagen). Molecular detection was performed using a nested PCR, targeting the small subunit (SSU) rRNA gene, employing primers HaemNF1/HaemNR2 in the first reaction and HaemF/HaemR2 in the second, generating an amplicon of ~480 bp. Haemocystidium DNA was detected in 36/114 (31.6%) samples by PCR, while intraerythrocytic stages observed in 25 samples by microscopy (21.9%) were consistent with Haemocystidium spp. Morphologically, parasites appeared as elongated or irregular forms within erythrocytes, occasionally causing host cell distortion. The higher detection rate achieved using PCR indicates an increased sensitivity compared with microscopy, although DNA sequencing is required to confirm amplicon specificity. These findings show that Haemocystidium infections are relatively common in freshwater turtles and emphasise the importance of combining molecular and morphological approaches for parasite detection.