Abstract：
Understanding the dynamic change in abundance of both fecal and opportunistic waterborne pathogens in urban surface water under different abiotic and biotic factors helps the prediction of microbiological water quality and protection of public health during recreational activities, such as swimming. However, a comprehensive understanding of the interaction among various factors on pathogen behavior in surface water is missing. In this study, the effect of salinity, light, and temperature and the presence of indigenous microbiota, on the decay/persistence of Escherichia coli and Pseudomonas aeruginosa in Rhine River water were tested during 7 days of incubation with varying salinity (0.4, 5.4, 9.4, and 15.4 ppt), with light under a light/dark regime (light/dark) and without light (dark), temperature (3, 12, and 20 °C), and presence/absence of indigenous microbiota. The results demonstrated that light, indigenous microbiota, and temperature significantly impacted the decay of E. coli. Moreover, a significant (p<0.01) four-factor interactive impact of these four environmental conditions on E. coli decay was observed. However, for P. aeruginosa, temperature and indigenous microbiota were two determinate factors on the decay or growth. A significant three-factor interactive impact between indigenous microbiota, temperature, and salinity (p<0.01); indigenous microbiota, light, and temperature (p<0.01); and light, temperature, and salinity (p<0.05) on the decay of P. aeruginosa was found. Due to these interactive effects, caution should be taken when predicting decay/persistence of E. coli and P. aeruginosa in surface water based on a single environmental condition. In addition, the different response of E. coli and P. aeruginosa to the environmental conditions highlights that E. coli monitoring alone underestimates health risks of surface water by non-fecal opportunistic pathogens, such as P. aeruginosa. KEY POINTS: Abiotic and biotic factors interactively affect decay of E. coli and P. aeruginosa E.coli and P.aeruginosa behave significantly different under the given conditions Only E. coli as an indicator underestimates the microbiological water quality.
摘要：
了解不同非生物和生物因素下城市地表水中粪便和机会性水性病原体丰度的动态变化，有助于预测娱乐活动中的微生物水质和保护公共卫生。比如游泳。然而,缺乏对地表水中病原体行为的各种因素之间相互作用的全面了解。在这项研究中,盐度的影响，光,温度和本地微生物群的存在，在不同盐度（0.4、5.4、9.4和15.4ppt）的孵育7天期间，对莱茵河中大肠杆菌和铜绿假单胞菌的腐烂/持久性进行了测试，在光/暗状态下（亮/暗）和没有光（暗），温度（3、12和20°C），以及土著微生物群的存在/不存在。结果表明，光，土著微生物群，和温度显著影响大肠杆菌的衰变。此外，观察到这四种环境条件对大肠杆菌衰变的显著(p<0.01)四因素交互影响。然而,铜绿假单胞菌,温度和本地微生物群是衰减或生长的两个决定性因素。土著微生物群之间存在显著的三因素相互作用影响，温度,和盐度(p<0.01)；土著微生物群，光,和温度(p<0.01)；和光，温度,发现盐度（p<0.05）对铜绿假单胞菌的腐烂。由于这些互动效应,在基于单一环境条件预测地表水中大肠杆菌和铜绿假单胞菌的衰变/持久性时应谨慎。此外,大肠杆菌和铜绿假单胞菌对环境条件的不同反应突出表明，仅大肠杆菌监测就低估了非粪便机会性病原体对地表水的健康风险，例如铜绿假单胞菌。关键点：非生物和生物因素相互作用地影响大肠杆菌和铜绿假单胞菌的腐烂。在给定条件下，大肠杆菌和铜绿假单胞菌的行为显着不同。只有大肠杆菌作为指标低估了微生物水质。
