Development and Evaluation of Procedures for Detection of Infectious Microsporidia in Source Waters

EPA Grant Number: R828042
Title: Development and Evaluation of Procedures for Detection of Infectious Microsporidia in Source Waters
Investigators: Rochelle, Paul A. , Leitch, Gordon , Visvesvara, Govinda
Current Investigators: Rochelle, Paul A. , Johnson, Anne M. , Leitch, Gordon , Visvesvara, Govinda
Institution: Metropolitan Water District of Southern California , Morehouse School of Medicine
Current Institution: Metropolitan Water District of Southern California , Centers for Disease Control and Prevention , Morehouse School of Medicine
EPA Project Officer: Hahn, Intaek
Project Period: May 1, 2000 through May 1, 2002
Project Amount: $294,635
RFA: Drinking Water (1999) RFA Text |  Recipients Lists
Research Category: Drinking Water , Water


Microsporidia were included on the USEPA's Contaminant Candidate List and are considered a high priority group of organisms. However, very little is known about the occurrence of microsporidia in environmental water sources and there is a critical need to determine the role water plays in the epidemiology of this group of parasites. Moreover, there are no routine methods for detection of microsporidia in water. Therefore, the objectives of this research are to develop concentration and purification methods for recovery of microsporidia from environmental waters, evaluate molecular and microscopic methods for detection of Enterocytozoon bieneusi, Encephalitozoon intestinalis and Nosema algare, determine the viability and infectivity of detected spores, and determine the occurrence of infectious microsporidia in source waters.


The recovery and purification methods which will be evaluated include filtration of water samples using a variety of different filter formats and porosities (capsule filters, dual filtration, stacked foam filters), immunomagnetic separation, and density gradient centrifugation. Optimized PCR assays and microscopic methods will be used for detection and identification. Viability will be assessed using a spore germination assay coupled with a nucleic acid stain, a fluorescent dye exclusion assay, and phase contrast microscopy. Infectivity will be determined by inoculating spores into cell cultures and detecting infections using molecular and microscopic methods.

Expected Results:

The expected products of this research will be optimized and validated methods for detection of infectious microsporidia in environmental waters. Also, information will be obtained on the prevalence of microsporidia in environmental waters. This information will allow the water industry and public health officials to determine the extent of microsporidia contamination in water and hence determine whether water represents a significant route of transmission for these parasites.

Publications and Presentations:

Publications have been submitted on this project: View all 4 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 2 journal articles for this project

Supplemental Keywords:

drinking water, human health, pathogens, monitoring, biology., RFA, Scientific Discipline, Health, Water, Environmental Chemistry, Health Risk Assessment, Environmental Microbiology, Risk Assessments, Environmental Monitoring, Drinking Water, microbial contamination, pathogens, monitoring, detection, spore germination assay, exposure and effects, exposure, encephalitozoon intestinalis, infectious disease, public health, treatment, microbial risk management, parasites, phase contrast microscopy, infectivity, microsporidia, nosema algare, water treatment, contaminant candidate list, enterocytozoon bieneusi

Progress and Final Reports:

  • 2000
  • Final Report