Phylogenetic Positioning of a Strongyloides stercoralis Isolate Recovered from a Korean Patient and Comparison with Other Asian Isolates

Abstract

Strongyloidiasis is caused by <i>Strongyloides stercoralis</i> and is one of the most neglected tropical diseases in tropical and subtropical regions. Although several strongyloidiasis cases have been reported in Korea, genetic analysis of Korean isolates is still incomplete. In this study, a parasite was isolated from a 61-year-old man diagnosed with strongyloidiasis during the treatment of lymphoma on his retroperitoneal lymph node. Diffuse symmetric wall thickening from the ascending to descending colon and a nematode-infected intestine was observed following microscopic examination. Genomic DNA was isolated from a patient tissue block, and <i>S. stercoralis</i> was identified by PCR and sequencing (18S rDNA). In order to determine phylogenetic location of a Korean isolate (named KS1), we analyzed <i>cox</i>1 gene (500-bp) and compared it with that from 47 previous <i>S. stercoralis</i> isolates (28 human isolates and 19 canid isolates) from Asian countries. Our results showed that phylogenetic tree could clearly be divided into 5 different groups according to hosts and regions. KS1 was most closely related with the Chinese isolates in terms of genetic distance.

Prevalence and risk factors of human Balantidium coli infection and its association with haematological and biochemical parameters in Ga West Municipality, Ghana

“…Significant thrombocytopenia was evident in B. coli infected individuals which was worsened in co-infection state. Furthermore, a reduction in levels of sodium, chloride and bicarbonate ions was observed in the infected individuals as was previously reported by Yu et al [ 14 ]. In that case report, mild anaemia, hypokalemia, hyponatremia, and hypochloremia were observed as well as occult blood in stool samples.…”

“…Indeed, human balantidiosis prevalence of 28, 29, and 12 % were reported in Papua New Guinea, Bolivia and Venezuela, respectively [ 9 , 12 , 13 ]. In addition, in China [ 14 ], Peru [ 15 ], and India [ 16 ], cases of balantidiosis in human were described. However, in Ghana, a cross-sectional study, carried out in 2020, in the Ga West Municipality in the Greater Accra Region of Ghana identified asymptomatic B. coli infection in nine individuals in Opah and Onyansana communities [ 10 ].…”

“…In that case report, mild anaemia, hypokalemia, hyponatremia, and hypochloremia were observed as well as occult blood in stool samples. Reduction in these ions could be as a result of diarrhea experienced by all infected individuals, while the presence of occult blood in all studied individuals could be as a result of parasite-induced colitis [ 14 ]. Reduction in albumin levels confirms the association of malnutrition with balantidiosis, as highly documented in several parasitic studies [ 9 , 29 – 31 ].…”

Comparison of different PCR amplification targets for molecular diagnosis of Strongyloides stercoralis

“…This could be due to genetic variability of S. stercoralis in the sequence of the primers with no complete complementarity, and this could generate weak and unstable junctions to the DNA template, resulting in no detectable products or indistinct bands. The genetic variability of the 18S rDNA of S. stercoralis has been widely reported (Hasegawa et al 2009;Bae et al 2020;Bradbury et al 2021).…”

Seropositivity Rates of Strongyloides stercoralis Antibody in the Southeastern Region of Republic of Korea: A Single-Center Retrospective Study

“…In the Republic of Korea (Korea), the first case of strongyloidiasis was reported in 1914, and approximately 35 cases have been reported in the literature [3,[5][6][7][8][9][10][11][12][13][14]. However, the seroprevalence of S. stercoralis infection has not yet been investigated in Korea.…”