This study measured the effect of germicidal ultraviolet (UV) light on Giardia lamblia and Giardia muris cysts, as determined by their infectivity in Mongolian gerbils and CD-1 mice, respectively. Reduction of cyst infectivity due to UV exposure was quantified by applying most probable number techniques. Controlled bench-scale, collimated-beam tests exposed cysts suspended in filtered natural water to light from a low-pressure UV lamp. Both G. lamblia and G. muris cysts showed similar sensitivity to UV light. At 3 mJ/cm2, a dose 10-fold lower than what large-scale UV reactors may be designed to provide, > 2-log10 (99 percent) inactivation was observed. These results, combined with previously published data showing other protozoa and bacteria have similar, high sensitivity to UV light, establish that UV disinfection of drinking water is controlled by viruses which may require over 10-fold more UV dose for the same level of control.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/s0043-1354(01)00412-2 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Environmental surveillance of Cryptosporidium and Giardia in surface supply water and treated sewage intended for reuse from an urban area in Brazil.
Environ Pollut
December 2024
Department of Environmental Analysis, Division of Microbiology and Parasitology, Environmental Company of the São Paulo State (CETESB), Brazil.
Environmental monitoring of protozoa, with the potential to trigger diseases, is essential for decision-making by managing authorities and for the control of water surveillance. This study aimed to detect and quantify Cryptosporidium oocysts and Giardia cysts in surface water for drinking water supply and treated sewage for reuse in the city of São Paulo. Samples collected bimonthly for one year were concentrated using the USEPA 1623.
View Article and Find Full Text PDFUsing To Model Fecal-Oral Transmission of in Mice.
mBio
February 2023
Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA.
There are several species that colonize humans, but only Entamoeba histolytica causes severe disease. E. histolytica is transmitted through the fecal-oral route to colonize the intestinal tract of 50 million people worldwide.
View Article and Find Full Text PDFDetection and identification of Giardia species using real-time PCR and sequencing.
J Microbiol Methods
October 2021
Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Waterborne Disease Prevention Branch, Atlanta, GA, USA. Electronic address:
We report a specific region of Giardia spp. 18S ribosomal RNA (18S rDNA) that serves as an ideal target for quantitative PCR (qPCR) detection and sequencing to identify Giardia species, including the clinically-relevant G. duodenalis, in clinical and environmental samples.
View Article and Find Full Text PDFHousehold slow sand filter to treat groundwater with microbiological risks in rural communities.
Water Res
November 2020
Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, 400 Trabalhador São-carlense Avenue, Zip code: 13566-590, São Carlos, São Paulo, Brazil. Electronic address:
Household slow sand filters (HSSFs) improve the quality of life in rural communities as they provide safe water. However, HSSFs require time for the growth of the biological layer (schmutzdecke) to achieve maximum performance, especially when groundwater is used as it normally has few nutrients. In this ripening period, pathogenic microorganisms can pass through the filter.
View Article and Find Full Text PDFAnalytical challenges and perspectives of assessing viability of cysts and oocysts by live/dead simultaneous staining.
Environ Technol
January 2022
Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, São Carlos, Brazil.
and are pathogenic protozoa often present in the environment in their infective form(cysts and oocysts). These parasites are very resistant to disinfection, which makes them important target organisms in environmental quality monitoring and sanitation. Viability assessment provides an interpretation of cell inactivation, and it can be evaluated by membrane integrity as well as enzyme activity, using different staining methods.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!