Re-survey of Blastocystis infection in free-living birds from urban Xinxiang city

Abstract

Blastocystis is the most ubiquitous intestinal protozoan parasite found in humans and animals worldwide. Commonly, ST7 and ST6 are the major Blastocystis subtypes reported in birds, and their frequencies fluctuate greatly with various factors. However, little literature is available on the prevalence and subtype characteristics of this parasite in free-living wild birds in the same city. For this purpose, a total of 114 fresh fecal specimens were collected from wild free-living birds in urban districts of Xinxiang city and tested for Blastocystis using PCR of the barcoding region of the small subunit ribosomal RNA (SSU rRNA) gene. The positive isolates were subsequently subtyped by sequence analysis, and Blastocystis was detected in 19 of the fecal specimens, with a prevalence of 16.7% (19/114), and only ST7 was identified. As a zoonotic subtype, the potential transmission threat of Blastocystis to humans could not be ignored. Interestingly, the findings in the current study were significantly different from the lower prevalence and inconsistent subtypes detected in previous studies, suggesting the incidence of Blastocystis ST7 in birds depends on multiple factors, while simultaneously exposing its non-pathogenic host adaptability.