Investigation of the occurrence of Toxoplasma gondii oocysts, Giardia spp. cysts and Cryptosporidium spp. oocysts in water reuse samples

• Grant number: 15/05882-7
• Support Opportunities: Regular Research Grants
• Duration: October 01, 2015 - September 30, 2017
• Field of knowledge: Engineering - Sanitary Engineering - Environmental Sanitation
• Principal Investigator: Maria Tereza Pepe Razzolini
• Grantee: Maria Tereza Pepe Razzolini
• Host Institution: Faculdade de Saúde Pública (FSP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Introduction: Facing the water crisis requires strategies such as water reuse as the strategy for the management of water resources either in scarcity situations as for the establishment of future policies. Though, aspects related to this practice cannot be ignored as health effects of exposure to these waters. The evaluation of parasitological quality of reuse water should be carried out as well as to estimate the level of risk to which the population is exposed. Pathogenic protozoa such as Toxoplasma gondii, Giardia and Cryptosporidium are circulating in the environment and therefore the detection of their presence and concentration should held to support discussions for establishing water reuse policies since, in our country, there is no regulation on the matter. Objectives: The objective of the research is to quantify (oo) cysts of Giardia and Cryptosporidium in reuse water samples, to implement of T. gondii oocyst quantification technique samples of reuse water, to contribute with data to the construction of conceptual model of exposure to determine the dose and thus estimate the risk of infection with these protozoa. Method: Forty eight samples will be collected weekly in WWTPE in São Paulo city during 12 months. The samples will be collected according to method 1623.1/USEPA 2012 for the quantification of (oo) cysts of Giardia and Cryptosporidium. Detection of T.gondii will be accomplished by molecular techniques where DNA extraction will be carried out with Qiagen QiAmp DNA® according to the manufacturer's instructions. PCR will be directed to the detection of 286 base pair fragment of T. gondii B1 gene according to Pelloux et al. (1997). The fragment 286bp bands, indicative of the presence of T. gondii, will be determined by comparison with standards fragments of 50 base pairs, subjected to electrophoresis on the same gel. The exposure scenario to estimate the risk of infection will be designed using the approach of Quantitative Microbiological Risk Assessment (QMRA). Expected Results: The results expected from this research are: to obtain results for the presence and concentration of pathogens - Giardia, Cryptosporidium and T. gondii - in water reuse samples for street washing and possible other uses in urban area ; to get information concerned the distribution of these protozoa in water reuse; to obtain data to support to estimate of probability of infection by ingestion / inhalation of water reuse; to capacity of laboratory staff to perform the protozoan T.gondii detection technique from environmental samples; to acquire background to participate in technical discussions concerning methodological updates and setting standards of these organisms in water intended for urban reuse. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

RAZZOLINI, M. T. P.; BRETERNITZ, B. S.; KUCHKARIAN, B.; BASTOS, V. K.. Cryptosporidium and Giardia in urban wastewater: A challenge to overcome. Environmental Pollution, v. 257, FEB 2020. (15/05882-7)