Microbial pollution of water from agriculture

Abstract

Microbial contamination of small streams in agricultural areas was monitored for two years. Microbiological indicators of faecal pollution (faecal coliforms, <I>Escherichia coli</I> and intestinal enterococci were detected by standard methods based on the cultivation of bacteria on selective media). The obtained results showed that running contamination of streams from agricultural areas was not extremely high, but it showed marked seasonal fluctuations (the average values and maximal values revealed great differences). Microbial contamination also increased several times in relation to high precipitation. The water quality in three (and/or four) localities exceeded the acceptable counts of faecal coliforms and enterococci given by the Czech legislation (40 CFU/ml for faecal coliforms and 20 CFU/ ml for enterococci). In agriculturally polluted streams, there were detected more enterococci than faecal coliforms, and also some less frequent species related to farm animals (<I>Streptococcus equines</I> and <I>S. bovis</I>) or plant rests (<I>E. mundtii, E. gallinarum, E. casseliflavus</I>) were present. <I>E. faecalis</I> and <I>E. faecium</I> strains (these are the most common species related to human faecal pollution) were less frequent there.