Effect of Air Ions on Submicron T1 Bacteriophage Aerosols

Abstract

Effect of air ions on submicron Ti bacteriophage aerosols. Appl. Microbiol. 14:888-891. 1966.-The effect of a high concentration of ionized air molecules on sampling Ti phage aerosols of submicron particle size was evaluated by comparing the phage recoveries of all-glass impingers (AGI-4) and type 6 filter papers. Sampler recoveries of all ionized aerosols were less than the recoveries of nonionized control aerosols. These reductions in recovery were greater with positive ions than with negative ions or ions of mixed polarity. The AGI-4 allowed considerable slippage, which was not affected by the air ions. Type 6 filter paper recoveries were less than AGI-4 recoveries. The air ions did not appear to affect the aerosol particle size as determined by an electron microscope.

Methods for Sampling of Airborne Viruses

“…Harstad also reported that filters are very destructive for this bacterial virus but are the most efficient at collecting submicrometer particles and that the fritted bubbler is the least efficient sampler, with a physical loss of over 80% of the sample (66). These differences in the recovery rates of AGI samplers and filters were confirmed in a later study (64). The gentler sampling process leading to better recovery of infective viruses seems to be the main reason for the wide use of AGI samplers in aerovirology.…”

“…For example, phage X174 is more susceptible to ozone than are phages MS2 and T7 (133). Ions in the air can also reduce the recovery rate of certain viruses, such as aerosolized T1 bacteriophage, with positive ions having the most detrimental effect (64).…”

“…In comparison studies, filters often provide the best physical recovery of nanoscale particles, but the filtering process can damage viruses and complicate the analysis, especially if culture is used to assess virus levels. Comparative studies using culture as an analytical tool have shown that filters are less efficient than other, less destructive methods, such as liquid impingers, for recovering airborne infectious viruses (64,66,132).…”

“…Surrogate viruses, such as bacteriophages of E. coli and other bacteria, can be used to mimic the behavior of pathogenic viruses. Bacteriophages of the order Caudovirales, such as T7-like ( (64,66), and T5-like (69) bacteriophages, were the first surrogates used. The genomic material of these bacteriophages consists of dsDNA, the capsid is nonenveloped, and the presence of a tail for host recognition renders the viruses susceptible to physical damage.…”

Comparison of Polycarbonate and Polytetrafluoroethylene Filters for Sampling of Airborne Bacteriophages

“…The viral aerosol size will depend on a variety of factors, including the aerosol source as well as its nature, its concentration, and its distribution in the environment (Wichmann et al 2000). Several samplers, such as liquid impingers (Verreault et al 2008), slit samplers (Thomas 1970;Dahlgren et al 1961), and filters (Harstad 1965;Happ et al 1966;Tseng and Li 2005) are avail-able to sample viral aerosols. The efficacy of these samplers for airborne viruses most often depends on the recovery of infectious viral particles and, therefore, mainly on the preservation of viral integrity.…”