A new duplex reverse transcription PCR for simultaneous detection of viable Cryptosporidium parvum oocysts and Giardia duodenalis cysts / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To simultaneously detect viable Cryptosporidium parvum oocysts and Giardia duodenalis cysts for the purpose of reducing time and cost spent.</p><p><b>METHODS</b>A duplex reverse transcription polymerase chain reaction (RT-PCR) method was newly developed.</p><p><b>RESULTS</b>Using duplex RT-PCR method for the hsp70 gene, viable (oo)cyst concentrations of 10(1) and 10(3) (oo)cysts/100 microL could be detected for C. parvum and G duodenalis, respectively. However, after heat-shock stimulation the expression of hsp70 mRNAs was detectable at 10(0) and 10(1) (oo)cysts/100 microL concentrations of C. parvum and G duodenalis, respectively. Thus, the detection sensitivity was significantly increased when the viable (oo)cysts were exposed to heat shock.</p><p><b>CONCLUSION</b>This study describes a new duplex RT-PCR method for hsp70 gene to detect the viable (oo)cysts of the C. parvum and G duodenalis with less time consumed and at a lower cost. This newly developed duplex RT-PCR method may be used to detect these parasites not only in aquatic environments but also in clinical samples.</p>

Detection and molecular characterization of enteroviruses in Korean surface water by using integrated cell culture multiplex RT-PCR / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To identify waterborne enteric viruses in Korean surface water.</p><p><b>METHODS</b>Integrated cell culture (ICC)-multiplex reverse transcription-polymerase chain reaction (RT-PCR) was simultaneously designed to detect coxsackieviruses (CV), polioviruses (PV), and reoviruses (RV). ICC-multiplex RT-PCR and phylogenetic analysis were conducted using 21 total culturable virus assay (TCVA)-positive sample-inoculated cell cultures.</p><p><b>RESULTS</b>CV and RV were detected in 9 samples each, and 3 samples were positive for both CV and RV. PV was not detected in any sample. Molecular phylogenetic analysis of the VP1 gene sequences revealed that CV types B2 and B4 predominated in Korean surface water, and the nucleotide sequences of CV type B2 were clustered with those of CVs isolated from China and Japan. The results suggested that the evolution of these viruses occurred in a region-specific manner.</p><p><b>CONCLUSION</b>CV and RV are detectable in Korean surface water, with a predominance of CV type B2, and the evolution of CV type B2 occur in a region-specific manner.</p>

Influence of Physicochemical Environmental Factors on the Occurrence of Waterborne Viruses in Korean Surface Water

In order to survey the occurrence of waterborne viruses in Korean surface water, a total of 192 water samples from July 2003 to January 2006 were collected and analyzed. The presence of waterborne viruses was investigated by total culturable virus assay (TCVA) using buffalo green monkey kidney (BGMK) cells. The results showed that 63 of 192 samples (32.8%) were positive for waterborne viruses with the average concentration of 3.1+/-18 most probable numbers (MPN)/100 L. The relationship between the occurrence of the viruses and the physicochemical environmental factors revealed that there was a significant correlation between the turbidity of water and the occurrence of the viruses. It was also noted that the water temperature might have some relationship with the occurrence of the viruses, as the frequency of the viruses was higher in low temperature or winter season. Therefore, the occurrence of waterborne viruses in Korean surface water might be affected by the physicochemical environmental factors such as turbidity and water temperature.