Quantification and analysis of the viability of (oo)cysts of pathogenic protozoa in sewage sludge

Author(s)

Medeiros, Raphael Correa ^[1] ; Daniel, Luiz Antonio ^[2]

Affiliation

^[1] Univ Fed Santa Maria, Dept Engn & Tecnol Ambiental, Linha 7 Setembro, BR-386, Km 40, BR-98400000 Frederico Westphalen, RS - Brazil

^[2] Univ Sao Paulo, Escola Engn Sao Carlos, Dept Hidraul & Saneamento, Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: ACTA SCIENTIARUM-TECHNOLOGY; v. 40, 2018.
• Web of Science Citations: 2

Abstract

For the use of sewage sludge, it is extremely important to consider the microbiological aspect of this byproduct that poses direct and indirect risks to public health as for its inadequate handling and use. This study aimed to quantify Giardia spp. cysts and Cryptosporidium spp. oocysts and infer their viability in sludge samples from two sewage treatment plants. The method used consisted of three successive centrifugations followed by immunofluorescence assay and staining with propidium iodide. Samples were 100% (14/14) positive for cysts and 57.1% (8/14) for oocysts, with higher concentrations and mean viability above 75%. The change in the treatment of activated sludge, from extended aeration to conventional system, caused no difference in the concentration and viability of (oo)cysts. (AU)

• FAPESP's process: 12/50522-0 - Environmental contamination by protozoa Giardia spp. and Cryptosporidium spp. and Ascaris suum: challenges of detection, removal and inactivation of infective forms
• Grantee: Regina Maura Bueno Franco
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 10/07902-1 - Assessment of the behavior of protozoa Giardia spp. and Cryptosporidium spp. and indicator microorganisms in the wastewater treatment and in river water
• Grantee: Raphael Corrêa Medeiros
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 11/08653-8 - Removal and inactivation of indicator microorganisms, Giardia spp. cysts and Cryptosporidium spp. oocysts in wastewater treatment plants
• Grantee: Luiz Antonio Daniel
• Support Opportunities: Regular Research Grants