Characteristics of bacterial and viral contamination of urban waters: a case study in Xi'an, China.

In order to gain knowledge on the presences of bacteria and viruses in urban waters, the authors started a long-term study on the microbiological quality of urban lakes and rivers in Xi'an, China. In the current study, enteroviruses were chosen as typical viruses and RT-nested PCR was conducted for their detection. Universal primers were designed for simultaneous detection of poliovirus, coxsackievirus, and enterovirus 71 which are the most frequently encountered enteroviruses in China. The RT-nested PCR protocol established in this study showed high sensitivity and specificity. The detection limit was equivalent to 0.038 CCID50 per litre by applying a modified adsorption-elution concentration method. No cross-reactivity was observed using the genome of pathogenic bacteria as of PCR template. The occurrence of enteroviruses was compared with fecal coliform count in a 6-month period from July to December 2006 for the urban waters. As a result, it was noticed that the presence of enteroviruses might not relate to the fecal coliform count so much. Statistical analysis also indicated that there was no significant correlation between the presence of enteroviruses and that of total bacteria, total coliform, and fecal coliform. [ABSTRACT FROM AUTHOR]