Solar Disinfection of Viruses in Polyethylene Terephthalate Bottles
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
Authors: Carratala, Anna; Calado, Alex Dionisio; Mattle, Michael J.; Meierhofer, Regula; Luzi, Samuel; Kohn, Tamar
Abstract
Solar disinfection (SODIS) of drinking water in polyethylene terephthalate (PET) bottles is a simple, efficient point-of-use technique for the inactivation of many bacterial pathogens. In contrast, the efficiency of SODIS against viruses is not well known. In this work, we studied the inactivation of bacteriophages (MS2 and phi X174) and human viruses (echovirus 11 and adenovirus type 2) by SODIS. We conducted experiments in PET bottles exposed to (simulated) sunlight at different temperatures (15, 22, 26, and 40 degrees C) and in water sources of diverse compositions and origins (India and Switzerland). Good inactivation of MS2 (>6-log inactivation after exposure to a total fluence of 1.34 kJ/cm(2)) was achieved in Swiss tap water at 22 degrees C, while less-efficient inactivation was observed in Indian waters and for echovirus (1.5-log inactivation at the same fluence). The DNA viruses studied, phi X174 and adenovirus, were resistant to SODIS, and the inactivation observed was equivalent to that occurring in the dark. High temperatures enhanced MS2 inactivation substantially; at 40 degrees C, 3-log inactivation was achieved in Swiss tap water after exposure to a fluence of only 0.18 kJ/cm(2). Overall, our findings demonstrate that SODIS may reduce the load of single-stranded RNA (ssRNA) viruses, such as echoviruses, particularly at high temperatures and in photoreactive matrices. In contrast, complementary measures may be needed to ensure efficient inactivation during SODIS of DNA viruses resistant to oxidation.
Echovirus plays a major role in natural recombination in the coxsackievirus B group
ARCHIVES OF VIROLOGY
Authors: Pu, Xufeng; Qian, Yongjiang; Yu, Yu; Shen, Hongxing
Abstract
Coxsakievirus (CV) B4, CVB5, and CVA9 belong to the species Enterovirus B. These viruses can cause viral encephalitis, aseptic meningitis, pancreatitis, flaccid paralysis, dilated myocarditis, and hand, foot, and mouth disease (HFMD). In order to analyze the evolution of CVB4, CVB5, and CVA9, we analyzed all of the available genome sequences of Enterovirus B (EVB) isolates and found that there were 12 putative recombination events that produced CVB4, 13 putative recombination events that produced CVB5, and 10 putative recombination events that produced CVA9. These recombination events involved 17 EVB serotypes as major or minor parents. The most active Echovirus (EchoV) appears to have been involved in 20 of the 35 recombination events, acting as one of the parental viruses of circulating CVB4, CVB5, and CVA9 strains. Our study indicates that EchoV plays a major role in recombination in the CVB group, and Echov_E30 is the most active in CVB4, whereas Echov_E3 and Echov_E25 are the most active in CVA9.