Occurrence and Subtype Distribution of Blastocystis in Smallholder Dairy Cattle in Bangladesh

Abstract

Blastocystis is a widespread protozoan known to induce digestive disorders in  humans and animals, including cattle globally. The parasite exhibits a significant  amount of genetic variability and is divided into 42 recognized subtypes (STs) in  mammals and birds. Sixteen of these subtypes are identified in cattle and 14 are  zoonotic. This study explored the distribution and genetic variations of Blastocystis  and its zoonotic potential in dairy cattle. Two hundred fresh fecal samples were  collected from smallholder dairy calves (aged <6 months) in two milk pocket areas  of Bangladesh: Sirajganj (n=100) and Pabna (n=100). A molecular study based on  PCR assay targeting the small subunit ribosomal RNA (SSU rRNA) gene was  employed to screen and subtype the parasite in the fecal samples. Analyses revealed  Blastocystis among 10% of the cattle, with 8% positive cases in samples from  Sirajganj and 12% in samples from Pabna. Various factors including sex, age, breed  groups, and fecal consistency were considered, although these were found to be  statistically insignificant. Out of the 20 positive Blastocystis isolates, only three  subtypes, namely ST10, ST21, and ST26, were identified where subtype ST10 was  the most prevalent. Notably, no zoonotic subtypes were detected in the fecal  samples, suggesting a lack of zoonotic significance. The findings provide insights  into the molecular epidemiology of Blastocystis infection in cattle, indicating its  low genetic diversity in the study areas. Further research is needed to determine the  exact frequency and genetic composition of Blastocystis and its zoonotic potential  in cattle in Bangladesh. 

J. of Sci. and Tech. Res. 6(1): 13-20, 2024