In Europe, the microbial water quality is evaluated mainly with the detection and quantification of indicators and pathogen bacteria: colony count at 22°C and 37°C, coliforms, E. coli, intestinal enterococci (IE), C. perfringens, S.aureus, P.aeruginosa and Salmonella spp. Nevertheless, these parameters for public health are still a topic of great controversy, because it’s well known their lack of a consistent correlation with viral pathogens. Only a viral indicator may be better suited to assess viral pollution, and for this purpose, special attention should be given to Human Adenovirus (HAdV). This virus is members of the genus Mastadenovirus in the Adenoviridae family, which comprises 52 serotypes classified into 7 species. The wide presence in environmental waters and its resistance to disinfection treatment justifies its utilizing as indicator. In the present work, the data obtained by one year monitoring of different water sources: wastewater treatment plant sewage (entry), wastewater treatment plant treated water (exit), seawater and river water were analyzed, in order to assess the HAdV occurrence compared to E. coli, IE and Somatic Coliphages (SC). Viral particles were detected and quantified (Log Genomic Copies GC) by biomolecular tests (PCR and quantitative PCR) on concentrated water samples obtained by two step tangential flow ultrafiltration starting from a volume of 1 L for wastewater entry and 10 L for wastewater exit, seawater and river water. The results revealed a mean of 76% positive HAdV samples: 100% in wastewater treatment system (entry and exit), 82% in river water and 42% in seawater. Geometric mean of viral concentration differed greatly among the water matrices: 10.2 ± 0.89 Log GC/L for wastewater treatment plant sewage, 8.6 ± 1.04 Log GC/L for wastewater treatment plant treated water, 3.9 ± 0.38 Log GC/L for seawater and 2.9 ± 1.43 Log GC/L for river water. The same samples were parallel analyzed by ISO methods for E. coli, IE and SC and obtained quantitative data were statistical not correlated with HAdV for wastewater and seawater while only in river water samples, multiple regression provided a significant correlation. The analyzed rivers received multiple discharges from non-point fecal pollution sources, thus these waters were not influenced by dilution events or water treatment. Moreover, in 42% of seawater samples and in 80% of river water samples, resulted ?excellent? according to classification of EU directive 2006/7/CE based on E. coli and IE detection, HAdV was detected. This data confirmed the higher viral environmental resistance comparing to bacterial one and the possible role of HAdV as water virological quality indicator.
Human Adenovirus as Water Virological Quality Indicator
VERANI, MARCO;FEDERIGI, ILEANA;CARDUCCI, ANNALAURA
2017-01-01
Abstract
In Europe, the microbial water quality is evaluated mainly with the detection and quantification of indicators and pathogen bacteria: colony count at 22°C and 37°C, coliforms, E. coli, intestinal enterococci (IE), C. perfringens, S.aureus, P.aeruginosa and Salmonella spp. Nevertheless, these parameters for public health are still a topic of great controversy, because it’s well known their lack of a consistent correlation with viral pathogens. Only a viral indicator may be better suited to assess viral pollution, and for this purpose, special attention should be given to Human Adenovirus (HAdV). This virus is members of the genus Mastadenovirus in the Adenoviridae family, which comprises 52 serotypes classified into 7 species. The wide presence in environmental waters and its resistance to disinfection treatment justifies its utilizing as indicator. In the present work, the data obtained by one year monitoring of different water sources: wastewater treatment plant sewage (entry), wastewater treatment plant treated water (exit), seawater and river water were analyzed, in order to assess the HAdV occurrence compared to E. coli, IE and Somatic Coliphages (SC). Viral particles were detected and quantified (Log Genomic Copies GC) by biomolecular tests (PCR and quantitative PCR) on concentrated water samples obtained by two step tangential flow ultrafiltration starting from a volume of 1 L for wastewater entry and 10 L for wastewater exit, seawater and river water. The results revealed a mean of 76% positive HAdV samples: 100% in wastewater treatment system (entry and exit), 82% in river water and 42% in seawater. Geometric mean of viral concentration differed greatly among the water matrices: 10.2 ± 0.89 Log GC/L for wastewater treatment plant sewage, 8.6 ± 1.04 Log GC/L for wastewater treatment plant treated water, 3.9 ± 0.38 Log GC/L for seawater and 2.9 ± 1.43 Log GC/L for river water. The same samples were parallel analyzed by ISO methods for E. coli, IE and SC and obtained quantitative data were statistical not correlated with HAdV for wastewater and seawater while only in river water samples, multiple regression provided a significant correlation. The analyzed rivers received multiple discharges from non-point fecal pollution sources, thus these waters were not influenced by dilution events or water treatment. Moreover, in 42% of seawater samples and in 80% of river water samples, resulted ?excellent? according to classification of EU directive 2006/7/CE based on E. coli and IE detection, HAdV was detected. This data confirmed the higher viral environmental resistance comparing to bacterial one and the possible role of HAdV as water virological quality indicator.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
