Restriction fragment length polymorphism (RFLP) analysis of Blastocystis spp. in symptomatic and asymptomatic individuals from Alexandria, Egypt

Abstract

Background: Blastocystis spp. is a unique enteric parasite commonly found in the intestines of humans and animals. In humans, prevalence up to 60% has been reported in tropical, subtropical, and developing countries. Currently 26 subtypes (STs) of Blastocystis have been described based on sequence analysis, 9 were reported in humans. Objectives: The aim of the work was to determine the different genotypes of Blastocystis spp. in symptomatic and asymptomatic individuals in Alexandria city, Egypt. Subjects and Methods: Examination of 100 stool samples was performed to detect Blastocystis collected from patients complaining of gastrointestinal (GI) disturbances and asymptomatic individuals. PCR restriction fragment length polymorphism analysis (PCR-RFLP) and sequencing of amplified products was performed for Blastocystis subtyping. Results: Out of 47 fecal samples positive only for Blastocystis spp. by microscopy, 39 patients presented with symptoms and 8 were asymptomatic participants. Blastocystis small subunit rRNA (SSU rRNA) was successfully amplified from 27 samples; 24/39 symptomatic and 3/8 asymptomatic. Among symptomatic patients, four STs were identified; ST3 was the most common (55%) followed by ST1 (20%), ST4 (15%) and ST2 (10%). While ST2 and ST4 were identified only in patients having GI symptoms, ST1 and ST3 were found in both symptomatic and asymptomatic participants. Amplicons of 7 samples from symptomatic patients were not digested after incubation with the restriction enzymes and could not be genotyped. Conclusion:Genotyping of Blastocystis spp. from fecal samples revealed the presence of four different subtypes: ST1, ST2, ST3 and ST4 with predominance of ST3. No statistically significant association could be observed between Blastocystis STs and clinical presentation of the studied subjects.RFLP analysis of Blastocystis spp.

Molecular Epidemiology and Genetic Diversity of the Enteric Protozoan Parasite Blastocystis sp. in the Northern Egypt Population

“…The overall prevalence of this parasite determined via the qPCR assay was 72.4% (597/825) (Table 1). As expected, this prevalence value of 72.4% was higher than those reported in other previous surveys conducted in Egypt, which ranged from 15.4% to 63.0% [39][40][41][42][43][44][45][46][47][48][49][50][51]. Indeed, in these latter studies, the parasite frequency was determined via direct microscopy of fecal smears or after in vitro cultivation of stool samples, which are conventional detection methods known to significantly underestimate the true incidence of the parasite compared to molecular assays [52,53].…”

Blastocystis SPP. infection prevalence and associated patient characteristics as predictors among a cohort of symptomatic and a symptomatic Egyptians

“…34.9 Data presented as n (%), +ve = positive, -ve = negative, ( # ) % of Blastocystis within the same group, (*) P-value ˂ 0.2 is significant. 9), (11,12): PCR positive samples showing distinct band at 600 bp; ( 8), ( 10), (13)(14): PCR negative samples ). Despite the relatively high prevalence of gut parasites in our study population, all of them were protozoa and there was no case with helminthic infection.…”

Molecular diagnosis and subtyping of Blastocystis sp.: Association with clinical, colonoscopic, and histopathological findings

“…Regarding clinical features of Blastocystis infection, literature reported several symptoms, such as abdominal pain, anorexia, flatulence, nausea, diarrhea, in addition to association with IBD. [ 4 , 6 ] Blastocystis has also been regarded as an opportunistic pathogen in immunocompromised patients. [ 7 ] On the other hand, other studies proposed Blastocystis sp.…”

“…might help in determining the pathogenicity of Blastocystis sp. [ 4 ] Regarding pathogenicity, we tried to associate the different detected subtypes of Blastocystis sp. to abnormal colonoscopic and histopathological findings.…”