The Study of Nucleotide Sequences of Mitochondrial Cytochrome c Oxidase Subunit1 (Cox1) of Strongyloides stercoralis from Patients in Vajira Hospital

Abstract

Strongyloides stercoralis (S. stercoralis) is an intestinal roundworm with an estimated 100 - 370 million people infected globally. The infection in immunocompromised patients is more severe due to septicemia caused by tissue and organ invasion by parasites. Mitochondrial cytochrome c oxidase subunit 1 (COX1) gene has a low degree difference in nucleotide sequences in the same species but high across different species. This phenomenon can be used to identify and classify living organisms. This study aimed to assess nucleotide sequences of COX1 gene of S. stercoralis in patients from Vajira Hospital, Faculty of Medicine, Navamin- dradhiraj University. Clustering of S. stercoralis by phylogenetic tree of COX1 gene were analyzed in 25 samples of S. stercoralis positive stools in accordance with clinical data and laboratory results to obtain preliminary correlations of clusters, domicile, clinical symptoms and white blood cell count. The nucleotide sequences of COX1 gene were divided into 20 clusters. The genetic pairwise distance of S. stercoralis in some clusters were 0.000. Cluster 8 was found in HIV patient with disseminated strongyloidiasis. Cluster 8 and 14 were found in both genders. Eleven cases (44%), 6 cases (24%), 2 cases (8%) and 6 cases (24%) were found in Bangkok, Ratchaburi, Kanchanaburi and other provinces, respectively. The patients were 56% male and 44% female. The ≤ 60 years and > 60 years age groups were 52% and 48%, respectively. Leukocytosis and eosinophilia were 36% and 52%, respectively. The patients in less than 60 years age group were frequent anemic, dehydrated and alcoholic. Gastrointestinal symptoms andimmunocompromised patients were found in the > 60 years age group. Leukocytosis and eosinophilia were consistent with bacterial infections and S. stercoralis infection. In conclusion,stercoralis isolates were divided into 20 clusters by phylogenetic tree of COX1 gene sequences. The preliminary data of clusters of S. stercoralis, sources of the parasites, medical records and clinical manifestation have been reported.