Modified membrane-filter procedure for concentration of enteroviruses from tap water

Our plain-English summary of Modified membrane-filter procedure for concentration of enteroviruses from tap water, by P.A. Shields, S.A. Berenfeld, S.R. Farrah (Applied and Environmental Microbiology, 1985).

The study

• Authors: P.A. Shields, S.A. Berenfeld, S.R. Farrah
• Journal: Applied and Environmental Microbiology
• Published: 1985;49(2):453-5
• Cited by: 8 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Enteroviruses added to 114 liters of dechlorinated tap water were recovered in a 16-ml sample by a two-stage concentration procedure in which different types of membrane filters were used in each concentration stage. Viruses in tap water at pH 3.5 were first adsorbed to 10-in. (ca. 25.4-cm) epoxy-fiber glass filters (Filterite). Viruses adsorbed to these filters were eluted with a solution of 0.2 M sodium trichloroacetate buffered at pH 9 with 0.2 M lysine. Viruses in this solution were adsorbed to 47-mm asbestos filters (Seitz) without pH adjustment or other modification of the solution. Viruses were recovered from the Seitz filters with 16 ml of either Casitone or fetal calf serum at pH 9. With these procedures ca. 45% of several types of enteroviruses added to 114 liters of tap water could be recovered in the final 16-ml sample.

In plain English

This laboratory methods paper from the University of Florida described a way to concentrate enteroviruses (poliovirus, echovirus and coxsackieviruses) from large volumes of tap water so they could be detected. It did not study asbestos exposure or any disease. Asbestos appears only because the second-stage filters, Seitz filters, are made of asbestos. The authors added known amounts of virus to 114 liters of dechlorinated tap water acidified with acetic acid and passed it through an epoxy-fiber glass Filterite filter. They washed the viruses off with a sodium trichloroacetate and lysine solution at pH 9, then caught them on a 47-mm Seitz asbestos filter. The viruses were recovered from that filter in 16 ml of Casitone or fetal calf serum. More than 95% of the viruses in the wash adsorbed to the Seitz filters. Across 10 trials for each eluent, mean recovery of the added viruses was 54% with Casitone and 43% with fetal calf serum. The authors reported that about 45% of several types of enteroviruses could be recovered in the final 16-ml sample.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory methods study (development of a virus-concentration procedure using seeded tap water)
• Who was studied: 114-liter batches of dechlorinated tap water seeded with poliovirus 1, echovirus 1, or coxsackievirus B3, B4 or B5; 10 trials per eluent; University of Florida laboratory
• Exposure: No human or animal asbestos exposure was studied. Asbestos-based Seitz grade S filters (47 mm) were used as the second-stage virus-adsorbing filter.
• Main results:
  • Mean recovery of added enteroviruses was 54% with Casitone as the eluent and 43% with fetal calf serum (FCS)
  • Casitone eluent, all viruses combined: 10 trials, 54 plus or minus 18% of added viruses recovered; FCS eluent, all viruses combined: 10 trials, 43 plus or minus 11%
  • More than 95% of viruses in the first-stage eluate adsorbed to the Seitz filters
  • Acidifying tap water with hydrochloric acid or acetic acid allowed more than 99% of the enteroviruses studied to adsorb to Filterite filters in laboratory studies
  • The sodium trichloroacetic acid solution eluted 77% (variation printed as 20%) of the enteroviruses adsorbed to Filterite filters
• The authors' conclusion: The authors concluded that with their modified procedures about 45% of several types of enteroviruses added to 114 liters of tap water could be recovered in the final 16-ml sample

Related studies

• Detection of virus in water: sensitivity of the tentative standard method for drinking water — W.F. Hill, W. Jakubowski, et al. (1976)
• Comparative study of four microporous filters for concentrating viruses from drinking water — W. Jakubowski, W.F. Hill, et al. (1975)
• The influence of external aerodymanic factors on the measurement of the airborne concentration of asbestos fibres by the membrane filter method — A.M. Johnston, A.D. Jones, et al. (1982)
• Conversion of the asbestos fibre concentration recorded by means of the konimeter and the thermal precipitator to that expected by means of the membrane filter method — R.S. du Toit, T.C. Gilfillan (1979)
• Comparison of a fibrous aerosol monitor (FAM) with the membrane filter method for measuring airborne asbestos concentrations — P.J. Iles, T. Shenton-Taylor (1986)
• Three potential sources of microfungi in a treated municipal water supply system in sub-tropical Australia — N.B. Sammon, K.M. Harrower, et al. (2011)

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