E Rovini

Viral Removal by Wastewater Treatment: Monitoring of Indicators and Pathogens

The discharge of treated civil wastewater into natural waters or their reuse in industry and agriculture involves virological risks for the exposed population. Although European and Italian regulations do not require routine viral analysis of treated wastewater, a better understanding of viral contamination and resistance to treatments is needed to assess and control such risks. To this end, a wastewater treatment plant was monitored by analysing the sewage at the plant entry and exit points in order to quantify the initial presence and eventual reduction of adenovirus, Torque Teno virus, Hepatitis A virus, rotavirus, enterovirus, norovirus genogroups I and II, somatic coliphages, Escherichia coli and enterococci. The results reveal that treated water may still contain infectious human viruses and thereby represent a potential health hazard. No significant correlations were found between bacterial indicators and the viruses considered, confirming their inadequacy for virological risk assessment, while the best indicators for virus inactivation in recycled waters seem to be adenovirus, followed by somatic coliphages.

Assessment of microbial parameters as indicators of viral contamination of aerosol from urban sewage treatment plants

In order to evaluate possible indicators of viral aerosol contamination in sewage treatment plants, a year‐long study was carried out on the relationships between the presence of cytopathogenic viruses and the counts of total bacteria, faecal streptococci and somatic coliphages in samples collected at various distances from the aerosol source (aeration tank). The activated sludge plant studied proved to be a significant source of microbe‐bearing aerosol with high levels of viral contamination. When the virus was found in sewage, it was also found in the air, at least in the sites closest to the aeration tank. With regard to the possibility of using the chosen parameters as markers of viral contamination, the total bacteria and faecal streptococci counts were generally positively correlated with viral presence, while coliphage counts yielded no analogous relationship.

Detection and potential indicators of the presence of hepatitis C virus on surfaces in hospital settings

Aims: The risk of hepatitis C virus infection in hospital environments can be assessed not only by studying epidemiological data and work practices, but also by the detection of these viruses (or indicators thereof) in health‐care settings, on instruments etc.

Interference between enterovirus and reovirus as a limiting factor in environmental virus detection

Aims: Faecal material from raw sewage or other sources lacking effective treatment sometimes contaminates water for human consumption. The relevant Italian regulations therefore call for testing drinking and recreational water for the presence of enterovirus.

Analisi virologica dei mitili per la sicurezza alimentare ed il biomonitoraggio

Obiettivi : i mitili sono organismi filtratori che accumulano sostanze disciolte o in sospensione nell’acqua, concentrando in tal modo anche eventuali contaminanti come i microrganismi. Ai fini della sicurezza alimentare la normativa vigente considera soltanto parametri batteriologici, lasciando a discrezione dei laboratori specializzati la ricerca di virus. La biologia molecolare rappresenta una possibile soluzione ai problemi relativi alla ricerca di virus nei molluschi. Metodi : su campioni di mitili artificialmente contaminati sono state saggiate due diverse sostanze eluenti la Glicina 0.05 M pH 9 e Beef Extract 3% pH 9, (1:2) e due diversi metodi di estrazione in parallelo: uno che utilizza la protease k-fenolo/cloroformio e uno rapido il QIAamp Viral RNA Kit (Qiagen). Sono state, inoltre, messe a confronto le sensibilita di una RT-PCR e di una RT-nested PCR per la ricerca di enterovirus. Il protocollo piu sensibile per quanto riguarda l’eluizione, l’estrazione dell’RNA e la PCR, e stato applicato alle analisi sul campo, affiancando ad esso la ricerca colturale di virus citopatogeni e le analisi batteriologiche. I campioni risultati positivi alle analisi biomolecolari sono stati sottoposti a sequenziamento genico degli amplificati. Risultati : la Glicina ha mostrato la maggiore capacita di recupero virale, mentre per l’estrazione degli acidi nucleici e risultato piu efficiente il sistema QIAamp Viral RNA Kit e la reazione RT-nestedPCR ha evidenziato una sensibilita maggiore di cinque logaritmi rispetto alla reazione one-step. Fino ad ora sono stati analizzati 20 campioni di mitili, ed in uno di questi e stato rilevato Human poliovirus 1 isolate MAHONEY V001149, isolato anche su culture cellulari di BGM. Conclusioni : l’analisi virologica appare importante nel controllo di qualita dei mitili per la possibilita di individuare agenti patogeni non segnalati dalla ricerca dei comuni indicatori di contaminazione fecale, oltre che per il monitoraggio della circolazione acque del virus di importanza epidemiologica quali ceppi di poliovirus vaccinali, selvaggi e mutanti.