|DE MEJIA, MARICRUZ|
Submitted to: Journal of Water and Health
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/30/2003
Publication Date: 10/15/2003
Citation: Dowd, S.E., John, D., Eliopolus, J., Gerba, C., Naranjo, J., Pepper, I.L., Klein, R., Lopez, B., DeMejia, M., Mendoza, C.E. 2003. Confirmed detection of Cyclospora cayetanesis, Encephalitozoon intestinalis and Crytosporidium parvum in water used for agriculture and drinking. Journal of Water and Health. 1:117-123.
Interpretive Summary: Protozoa are single celled organisms capable of causing disease in Man. There are many different types of protozoa and several types have recently been discovered and are now known to cause disease. Examples are the Microsporidia, Cryptosporidium spp. and Cyclospora cayetanesis. Of these only Cryptosporidium has been shown to be waterborne, in other words it can be spread through contamination of drinking water sources. This publication details the development and use of molecular methods including the Polymerase Chain Reaction, sequencing, and sequence analysis to detect and confirm the identity of these protozoa in water samples obtained from Guatamala. These water samples are used for drinking and even for irrigation by the people in these areas. This study represents the first confirmed detection of Cyclospora cayetanesis in drinking water samples and the second confirmed detection of two species of microsporidia (Encephalitozoon intestinalis and Enterocytozoon bieneusi) in drinking water samples.
Technical Abstract: Human enteropathogenic microsporidia (HEM), Cryptosporidium parvum, Cyclospora cayetanesis, and Giardia lamblia are associated with gastrointestinal disease in humans. To date, the mode of transmission and environmental occurrence of HEM (Encephalitozoon intestinalis and Enterocytozoon bieneusi) and Cyclospora cayetanesis have not been fully elucidated due to lack of sensitive and specific environmental screening methods. The present study was undertaken with recently developed methods, to screen various water sources used for public consumption in rural areas around the city of Guatemala. Water concentrates collected in these areas were subjected to community DNA extraction followed by PCR amplification, PCR sequencing, and computer database homology comparison (CDHC). All water samples screened in this study had been previously confirmed positive for Giardia spp. by immunofluorescent assay (IFA). Of the 12 water concentrates screened, 6 showed amplification of microsporidial SSU-rDNA and were subsequently confirmed to be Encephalitozoon intestinalis. Five of the samples allowed for amplification of Cyclospora 18S-rDNA and 3 of these were confirmed to be Cyclospora cayetanesis while two could not be identified because of inadequate sequence information. Thus, this study represents the first confirmed identification of Cyclospora cayetanesis and Encephalitozoon intestinalis in source water used for consumption. The fact that the waters tested may be used for human consumption indicates that these emerging protozoa may be transmitted by ingestion of contaminated water.