Morphological and molecular investigation of free-living amoeba Sappinia spp. isolated from environmental and clinical samples in Thi-Qar province-southern Iraq

Abstract

Sappinia is a free-living amoeba, a single-celled living organism found in the environment. It has recently been attributed to being an opportunistic human pathogen. There are two known species of Sappinia: S. diploidea and S. pedata. The current study detected Sappinia species using morphological and genetic approaches in various environmental and clinical samples in the Thi-Qar province of southern Iraq. The study was conducted from February - September 2020; one hundred and two samples for this study were obtained from various environmental and clinical sources. PCR was carried out with a positive culture after the samples were cultivated on an NN-agar medium. Overall, the study showed that 53(51.96%) samples were positive on morphological characters as well as PCR analysis showed that only 47 (46.07%) ) of Sappinia morphologically positive samples were positive by using a specific primer. Sappinia spp. were observed in all types of samples of environmental and clinical sources except CSF, and clinical ear samples were negative. The current study showed two species of Sappinia that have similar morphology but differ in the diameter of trophozoite and cyst, number of nuclei, and cyst morphology. The current study will pave the way for additional epidemiological research by considering the presence of potential Sappinia species in various samples, whether from environmental or clinical sources, to better understand the function of Sappinia as a potential health danger to people. Keyword: Sappinia spp. Free-living amoeba, opportunistic amoeba, Thi-Qar, Iraq