Genetic diversity of Blastocystis hominis sensu lato isolated from humans in Poland

ABSTRACT

INTRODUCTION AND OBJECTIVES: Blastocystis hominis s. l. is one of the most commonly detected protozoa in the human large intestine. The aim of the study was to determine the genetic subtypes of Blastocystis hominis s. l. occurring in humans in Poland. MATERIALS AND METHODS: Stool samples from patients diagnosed in the Laboratory of the Department of Parasitology, National Institute of Public Health ­ National Institute of Hygiene (NIZP-PZH) and in the Parasitology Laboratory of the Hospital for Infectious Diseases in Warsaw were examined. Blastocystis subtypes were assayed based on the fragment of small-subunit ribosomal RNA gene sequences (SSU rDNA). RESULTS: The examined isolates were classified into five Blastocystis subtypes (STs), fifteen of which belonged to ST3, three to ST1, two to ST2, two to ST6, and one isolate belonged to ST7. In three cases the subtype of isolate was not identified. DISCUSSION AND CONCLUSIONS: In Poland, the subtypes ST1, ST2, ST3, ST4, ST6 and ST7 have been reported in humans so far. The ST6 and ST7 subtypes are rarely detected in humans in Europe. In Poland, the ST6 subtype was previously described in chickens. On the basis of the studies, it was found that Blastocystis isolated from humans in Warsaw show high genetic diversity. In order to determine the possible pathogenic potential of individual Blastocystis subtypes, special epidemiological studies are required.