Sirisena, Umeshika V.2024-11-202024-11-202013https://ir.lib.pdn.ac.lk/handle/20.500.14444/3775Cryptosporidium is an obligatory intracellular extracytoplasmic intestinal coccidian parasite that infects a variety of animals including humans. Human cryptosporidiosis is caused by several cryptosporidial species. Among them more common species are Cryptosporidium hominis and Cryptosporidium parvum. This is the first report of molecular analysis of Cryptosporidium species in paediatric diarrhoeal patients in Sri Lanka. This study identified Cryptosporidium species and examined the prevalence and distribution of Cryptosporidiosis in patients admitted to 4 different hospitals. Samples were concentrated by Formol- Ether sedimentation technique. Concentrated samples stained by the Modified Ziehl Neelson staining procedure. If the sample was stained positive for Cryptosporidium, remaining samples were concentrated by Sheather's sugar flotation technique. DNA was extracted from all MZN positive samples by using Promega DNA extraction kit. Cryptosporidium ribosomal gene fragment was amplified using PCR in the genomic DNA with Cry2 and Cry 4 primers by hot short method. The relative specificity of these primers for the amplification of Cryptosporidium parvum by PCR has been demonstrated previously. Agarose gel electrophoresis was performed in 1 x TBE buffer at using 1.5% agarose gel to visualize PCR products. MZN method showed cryptosporidial oocysts as dark pink colour spherical bodies with the size of about 4-5 urn in diameter. In this study 8 stool samples were positive for .Cryptosporidium species by MZN. The highest prevalence (13.6%) was detected in Teaching Hospital, Kandy and lowest prevalence (0%) was detected in the Teaching Hospital, Peradeniya. Out of 8 stain positive samples C. parvum was detected in 1 (12.5%) sample and other 7 (87.5%) samples were negative for C. parvum by peR. The majority of patients with cryptosporidiosis had watery diarrhoea and contact with goats when compared to contact with other animals. The majority of human Cryptosporidium isolates were identified as non-Cryptosporidillm parvum species (87.5%) and only one isolate was identifies as Cryptosporidium parvum (12.5%), suggesting the need for further extensive studies to explore the association of Cryptosporidium infection with diarrhea in children in Sri Lanka.en-USCryptosporidiumPediatric patientsThesis