2016 Volume 18 Issue 1 Pages 17-21
Cyanobacteria produce potent toxins which have been responsible for numerous livestock and human poisonings. Among cyanotoxins, microcystins, cylindrospermopsins and nodularins are known to cause acute and chronic illnesses. Concern about cyanotoxins in the dry zone water sources of Sri Lanka has grown due to a numerous negative health impacts, including the epidemic of Chronic Kidney Disease of unknown etiology (CKDu). The study aimed a region of high CKDu prevalence in Sri Lanka, Girandurukotte which consisted of CKDu and CKD patients and their well waters. Control samples were collected from other parts and all were analyzed in terms of potential cyanotoxin producers. A questionnaire analysis was carried out with 330 subjects (CKD n=33, CKDu n= 244 patients and healthy individuals n=53). Eleven factors showed significant difference (p<0.05) that could be related to the CKDu. Among them, well water source for drinking was (p=0) notable. Potential microcystin and cylindrospermopsin producing cyanobacteria were morphologically identified from 110 (CKD n=11, CKDu n=74 and Healthy individuals n=25) water samples. Compared to Girandurukotte patients' well water samples, cyanobacterial diversity was found to be less in healthy individuals' well waters. Among potential toxin producers, presence of Phormidium spp in CKDu patients' well waters were found to be significant (P=0.004) compared to other two populations. 50 CKDu and 15 CKD + healthy individuals' well water samples were assayed for partial mycE gene, cylindrospermopsin specific NRPS and PK genes and partial nodularin synthetase (nda) gene. Among these, presence of cylindrospermopsin producers (p= 0.049) and nodularin producing Nodularia species (p=0.0029) were found to be significant.
