Detection and quantification of microorganisms in domestic water reservoirs

• Grant number: 20/01478-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2020
• End date: June 30, 2023
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Hugo Miguel Preto de Morais Sarmento
• Grantee: Leandro Manoel Afonso Mendes
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Water quality is the most important factor that ensures public health. The purpose of water treatment plants is to provide a safe supply of drinking water to the population, ensuring the absence and limiting the growth of any organism that may be associated with pathogenicity. Regardless of the means of disinfection, it is common to find bacteria during the treatment and distribution of water. Most drinking water bacteria cannot be grown in the laboratory. However, counts based on cultivation plates are used worldwide as a standard protocol of water quality in drinking water treatment plants. Several studies have demonstrated the presence of microorganisms in drinking water or biofilms using more refined techniques such as flow cytometry (not used in Brazil with this application). This method is used for direct enumeration of the total cell concentrations in the water, with fluorescent staining of nucleic acids and detection of specific characteristics of the cells. Indeed, it is important to highlight reports of detection of several pathogens, reinforcing the importance of such findings for public health. In addition, the existing studies focus on countries where there are no residential water tanks in the distribution circuit, an element that can deteriorate the quality of the water stored there. The purpose of this work is to adapt and improve protocols to detect the presence of bacteria in residential water tanks, and to quantify them using the cell counting technique by flow cytometry (FCM).