Research On Enteric Viruses And Bacteria Indicator In Poyang Lake Of Nanchang

Objective:Detecting the contamination and its change of enteric virus in Poyang Lake,discussing the correlation between human enteric virus and bacteria indicators.Methods:In this study,water samples were taken from six locations along the Poyang Lake considering factors such as human sources and environmental impact,including Qingshan zha?Guanniao tai?Tuoshan?Wucheng,Xingzi?Jiujiang Dukou.According to the distribution characteristics of these six sites,Qingshan zha?Guanniao tai and Tuoshan are grouped to upstream while Wucheng and Xingzi are the midstream,and Jiangxi Dukou is the downstream of Poyang Lake where water flows into Yangtze River.All these sites were monitored for eight months(May 2016to January 2017),Water sample collection times were initially designed but adjusted according to actual situation,such no water samples were collected between July and August due to water overflowing.Water samples were processed in the laboratory according to established methods and tested for the followings:a)physical and chemical index(air temperature,water temperature,GPS coordinates);b)bacteria indicators(Aerobic bacterial Count,total coliform,fecal coliform,E.coli and enterococcus);and c)HUMAN enteric viruses(norovirus geno-groups I and II,enteroviruses,and adenoviruses).The detection of human enteric virus using two methods:the qualitative detection designed by Univerisity of Hawaii and load-charge filter method designed by Academy of military medical sciences.The bacteriological analyses were done according to the filter membrane method of GB/T 5750.12-2006?Standard Examination Methods for Drinking Water?of China.Results:There is widespread enteric virus contamination in Poyang Lake.In the qualitative detection of virus,results show that the positivedetection of norovirus geno-groups I was highest in spring and summer,with 100.00%and 66.70%respectively;the positive detection of norovirus geno-groups II was highest in spring and winter,with 58.30%and 50.00%,respectively;indicating statistically significant difference between summer and winter.The positive detection of enter virus was highest in spring and fall,with 83.33%and 75.00%respectively;the positive detection of adenoviruses was highest in spring and fall,with 83.33%and 75.00%respectively.The result show no statistical significant correlation in the detection of norovirus geno-groups I and norovirus geno-groups II in differernt sampling sites.It show statistical significant in detection of enteroviruses in differernt sampling sites(?~2=7.321 P=0.007),and the highest positive odd rate were showed in Xingzi and Jiujiang Dukou(71.43%).The highest positive rate of adenoviruses was 100.00%in Jiujiang Dukou.Through the quantitative detection,three viruses(norovirus geno-groups II,enteroviruses,and adenoviruses)were detected,the positive odd rate was 91.67%of adenoviruses,norovirus geno-groups II and enteroviruses were86.11%?77.78%.The positive detection rates of bacteria indicators(Aerobic bacterial Count,total coliform,fecal coliform,E.coli and enterococcus)were 100.00%?52.40%?38.00%?21.42%?40.48%,respectively.Aerobic bacterial Count,total coliform,fecal coliform,E.coli and enterococcus were positively correlate with air temperature and water temperature,and have statistically significance(P<0.001).Analysis of the correlation showed that the detection of traditional indicator bacteria,Aerobic bacterial Count and total coliform?and E.coli was positively correlation(P<0.01).No correlation among enteric viruses and no correlation between virus(norovirus geno-groups I and II,enteroviruses,and adenoviruses)and bacteria(Aerobic bacterial Count,total coliform,fecal coliform,E.coli and enterococcus).Besides bacteroides can not predict the detective of virus.Comparative analysis of the two methods employed in this study reveals that the qualitative experimental method established at the Hawaii laboratory and the quantitative detection method established showed no statistical significant correlation in detecting the selected enteric viruses(P<0.005).Conclusions:This study found that the Poyang Lake was contaminated with human sewage,and the presence of human enterovirus was detected in the water that meets the microbiological standard.It was found that the presence of indicating microorganisms did not represent the existence of the human enteric viruses,and there was no correlation in detection of bacterial indicator with human pathogenic viruses.Thus,it is not good enough to ues only indicating microorganism like E coli as water quality monitoring indicator,and additional indicator systems such as human enteric virus and needed in order to enhance current monitoring of water quality and improve the assessment of water related health risks.Results from the two quantitative methods for viral detection are not significantly different,indicating either of these method can be used in future,although each method had its advantages and disadvantages.