[Comparison of different methods for the detection of enteroviruses in drinking water]

Detection of enteroviruses in drinking water poses a very specific problem, since a very small number of particles have to be identified in huge water quantities. Currently, there are a number of methods to identify the concentration of virus particles and RNA templates to carry out RT-PCR, however, no standard method has yet been proposed.

The aim of this report is to suggest optimal methods for the preparation of RNA templates to carry out RT-PCR.

In this experimental study, two different methods were employed on preparing RNA template. The concentration of virus particles in a large (10 L) and small (1 L) quantity of water was determined by use of the electropositive microporous virology filter (method 1 and method 2). Elution and flocculation of the virals particles were performed by organic extraction (method 1) and inorganic extraction (method 2). The sensitivity of the methods was assessed by testing the artificially contaminated water with 10(1) to 10(5) virus-particles using 1-L and 10-L containers of water.

Method 1 detected 10(5) and 10(4) virus particles, method 2 10(5), 10(4) and 10(3) virus particles from 10 L and 1 L of water, respectively, yielding a statistically significant difference (p<0.01; chi2 = 6.061). Using two-step RT-PCR with nested PCR method, enteroviruses were detected in 42/100 (42%) samples of surface drinking water and in 83% of the same samples using RT-PCR without nested PCR.