An Association Between Blastocystis Subtypes and Colorectal Cancer Patients: A Significant Different Profile from Non-cancer Individuals

Citation:
Ali, S. H., M. A. M. Ismail, A. A. El-Badry, E. Y. Abu-Sarea, A. M. Dewidar, and D. A. Hamdy, "An Association Between Blastocystis Subtypes and Colorectal Cancer Patients: A Significant Different Profile from Non-cancer Individuals ", Acta Parasitologica, vol. 1, issue 1, pp. 1-12, 2022.

Abstract:

Purpose Blastocystis is a common enteric human parasite of non-conclusive pathogenicity which may be determined by subtype (ST) variation. Colorectal cancer (CRC) is considered one of the primary causes of cancer mortality. Blastocystis ST7 has been shown to reduce benefcial intestinal microbiota and may exacerbate CRC. This study assessed the possible association between Blastocystis STs and CRC in comparison to non-cancer patients.

Material and Methods A total of 200 fecal samples were obtained from CRC (100) and non-CRC (100) individuals attending Beni-Suef University Hospital, Egypt. Blastocystis was searched for in all samples using microscopy and culturing. Positive subculture samples were genetically sequenced and subtyped using conventional polymerase chain reaction (PCR). Blastocystis STs were determined by sequencing and a phylogenetic tree was created. Related patient characteristics and tumor stages were analyzed for association with presence of Blastocystis.

Results Blastocystis was identifed in 52% and 42% of CRC and non-cancer individuals, respectively. ST1, 2, and 3 were isolated from both cancer and non-cancer individuals; however, for the frst time, ST7 was only isolated from CRC stool samples with signifcant association. Associated patient characteristics were evaluated as predictors.

Conclusion Blastocystosis is highly prevalent in CRC patients, predominantly in the latest CRC grades and stages. To the best of our knowledge, this is the frst study to report the identifcation of Blastocystis ST7 in CRC patients. To determine whether certain STs of Blastocystis are associated with CRC would require further research, including the role played by
gut microbiota.

Keywords Blastocystis · Subtypes · Colorectal cancer · Egypt