Analysis of Sequence Variation among the Replicase Genes of F+-specific RNA Coliphages for Microbial Source Tracking in Korea

Abstract

Water contamination of various fecal sources can be the risk factor to human health by causing waterborne disease because of pathogenic microorganisms. We recovered F+ specific coliphages from various animal feces and human fecal samples. Approximately 1.7 kb of replicase gene regions of FRNA coliphages were amplified by RT-PCR and phylogenic analysis was performed using amplified nucleic acid sequences. From 80 samples of various animal (cow, chicken, pig and wild goose) and human feces, total 229 of FDNA and FRNA coliphages were isolated. F+ specific coliphages were most prevalent in wild goose feces (100 %) and were least prevalent in cow feces (10 %). Through RNase sensitivity spot assay, 57 (25 %) of FDNA coliphages and 173 (75 %) of FRNA coliphages were confirmed. FRNA coliphages showed higher presence ratio in every fecal pollution source than FDNA coliphages, especially, there were only FRNA coliphages (100 %) in cow and human feces, respectively. In phylogenic analysis based on replicase gene sequence information, human fecal source was clearly distinct from the other animal sources. As s result of principal coordinate analysis (PCoA) based on sequence information of FRNA coliphages replicase genes, human source were obviously distinguished from nonhuman sources. Moreover, sequence information of replicase gene from different animals is clearly distinctive each other except pig and goose source in both phylogenic and PCoA analysis. The results of phylogenic and PCoA analysis based on the whole sequences of replicase gene showed consistence with those of partial conserved region in replicase gene of FRNA coliphages.