Simultaneous detection of Cryptosporidium parvum and Giardia in sewage sludge by IC-PCR
R Rimhanen-Finne1, P Ronkainen, M L Hänninen
1Department of Food and Environmental Hygiene, Faculty of Veterinary Medicine, University of Helsinki, Finland.
Aims:
The aim of this study was to develop a method based on immunomagnetic capture and polymerase chain reaction (IC-PCR assay) for detection of Cryptosporidium parvum and Giardia intestinalis in sewage sludge.
Methods And Results:
The detection limit of the IC-PCR assay for both organisms was 625 oocysts and cysts ml(-1). By hybridization of PCR products the sensitivity could be increased to 125 oocysts and cysts ml(-1). Forty-four sludge samples from 12 wastewater treatment plants were examined. The samples positive for Giardia (9 out of 44) were from eight wastewater plants and the C. parvum genotype 2 samples (3 out of 44) originated from different sewage works.
Conclusions, Significance And Impact Of The Study:
IC-PCR offers the possibility to distinguish between Cryptosporidium and Giardia genotypes. This assay can be used to monitor the presence of these organisms in a community and to determine contamination of sludge used as soil amendment.
Insights
A new immunomagnetic capture and polymerase chain reaction (IC-PCR) assay effectively detects Cryptosporidium parvum and Giardia intestinalis in sewage sludge. This method aids in monitoring parasitic contamination in environmental samples.
Area of Science:
- Environmental microbiology
- Parasitology
- Molecular biology
Background:
- Cryptosporidium parvum and Giardia intestinalis are significant waterborne protozoan parasites.
- Sewage sludge can serve as a reservoir for these pathogens, posing risks to public health and the environment.
- Accurate detection methods are crucial for risk assessment and management.
Purpose of the Study:
- To develop and validate an immunomagnetic capture and polymerase chain reaction (IC-PCR) assay.
- To detect Cryptosporidium parvum and Giardia intestinalis in sewage sludge samples.
- To assess the assay's sensitivity and applicability in real-world environmental monitoring.
Main Methods:
- Development of an immunomagnetic capture technique combined with polymerase chain reaction (IC-PCR).
- Determination of the assay's detection limit for Cryptosporidium parvum and Giardia intestinalis oocysts/cysts.
- Application of the IC-PCR assay to analyze sewage sludge samples from multiple wastewater treatment plants.
- Enhancement of sensitivity through hybridization of PCR products.
Main Results:
- The IC-PCR assay achieved a detection limit of 625 oocysts and cysts/mL.
- Sensitivity was increased to 125 oocysts and cysts/mL with hybridization of PCR products.
- Giardia was detected in 9 out of 44 sludge samples from eight different plants.
- Cryptosporidium parvum genotype 2 was identified in 3 out of 44 samples from distinct sewage works.
Conclusions:
- The developed IC-PCR assay is a sensitive and specific method for detecting Cryptosporidium and Giardia in sewage sludge.
- The assay allows for the differentiation of Cryptosporidium and Giardia genotypes.
- This method provides a valuable tool for monitoring parasitic contamination in communities and assessing sludge safety for soil amendment.
