Faecal contamination indicator bacteria in water quality assessment: literature review

Abstract

The increasing use of water for different purposes and worldwide population growth has contributed to increase levels of pollution of aquatic systems. Currently, the contamination of these ecosystems is a problem, due to the constant dumping of domestic and industrial wastes as a constant source of environmental pollution. Control of the microbiological quality of fresh water and discharge requires targeted analysis to determine the presence of pathogenic microorganisms. The alternative for a reliable, economical and rapid microbiological water quality is the use of indicators of fecal contamination. Among the fecal pollution indicators used are total and thermotolerant coliforms, Escherichia coli and enterococci. Unlike pathogenic bacteria, indicator bacteria allows the sanitary classification of water for different uses, the determination of criteria and compliance of quality standards, the identification of contaminant discharges, the control of processes of water treatment, and epidemiological studies among others. This paper focuses on the main issues addressed in literature regarding the utility of fecal indicator bacteria in the assessment of water quality. Studies which demonstrate the feasibility of using E. coli and enterococci as indicators of fecal contamination for evaluation of water quality and the techniques used for their detection are presented, as well as the use of the rate E. coli/ enterococci just to determine the source of contamination. Moreover, it is briefly discussed the current situation in Cuba regarding this subject.