Natural infection of Blastocystis ST6 among commercial quails (Coturnix coturnix) in Penang, Malaysia

Blastocystis sp. is a unicellular, anaerobic intestinal protist regularly reported in humans and various animals worldwide. There seems to be little research on Blastocystis infection in poultry in Malaysia, and none on Blastocystis in quail specifically. In Malaysia, the consumption of quail meat and eggs is rapidly gaining popularity as a significant source of protein. It is, therefore, essential to explore the presence of Blastocystis in Malaysian quails in order to aid in the understanding of Blastocystis in this group of birds and their role in its transmission. Intestinal contents were collected from 90 commercial quails raised on two farms in Penang, Malaysia, in a multi-layer cage system with adequate farm management. Detection of Blastocystis sp. was by cultivation in modified Jones' medium supplemented with 10% horse serum. Giemsa-stained slides made from positive cultures were used for morphological studies whereas Blastocystis subtyping was conducted by using Polymerase Chain Reaction (PCR). A prevalence of 17.8% (16/90) was recorded for Blastocystis sp. in quail in this study. The most common forms detected in the in vitro culture medium were vacuolar and granular forms with cell diameters ranging from 9.09 μm to 33.33 μm. None of the quail birds screened had any visible gastrointestinal symptoms or signs. All successfully sequenced isolates were identified as Blastocystis sp. ST6, one of the potentially zoonotic subtypes of Blastocystis. This study posits that the quail birds may serve as reservoirs of zoonotic subtypes of Blastocystis. More studies are required to understand the source of Blastocystis infection to poultry under intensive care and the role of poultry animals in the transmission of Blastocystis to humans.