OBJECTIVETo establish a testing and evaluating method for filtration efficiency of the canister against microbial aerosol.

METHODSSerratia marcescens aerosol served as model of bacterial aerosol, Bacillus subtilis var niger aerosol as model of spores aerosol, bacteriophage f(2) aerosol as model of viral aerosol. Employing the microbial aerosol testing platform was established in lab, models of microbial aerosol generated artificially were sampled quantitatively by air samplers before and after filtrating by canisters, respectively. Filtration efficiency was determined by the concentration of microbial aerosol in the air sample before and after filtrating. The four canisters of 1-1, 1-2, 1-3, 1-4 were tested for the filtration efficiency against Serratia marcescens, Bacillus subtilis var niger and phage f(2) aerosol. The two canisters of 543 and 544 canisters equipped with active carbon were tested for the filtration efficiencies against Serratia marcescens aerosol.

RESULTSThe filtration efficiency of 1-1, 1-2, 1-3 canisters against Serratia marcescens, Bacillus subtilis var niger and phage f(2) aerosol was 100.000%. The filtration efficiency of 1-4 canister filtration efficiency against Bacillus subtilis var niger spores aerosol was 99.997% and efficiency of the other two aerosol was 100.000%. The filtration efficiency of the two canisters of 543 and 544 to those attached with active carbon against Serratia marcescens aerosol was 100.000%.

CONCLUSIONThe testing method might be used to evaluate the protective performance of the canister against microbiological aerosol. The effect of the canisters (including those equipped with active carbon) against microbiological aerosol should be reliable.

Aerosols ; Air Microbiology ; Bacillus subtilis ; isolation & purification ; Filtration ; methods ; Levivirus ; isolation & purification ; Respiratory Protective Devices ; standards ; Serratia marcescens ; isolation & purification ; Spores, Bacterial ; isolation & purification

We have examined isolation and identification protocols for three virus simulant candidates to biological warfare agents. MS2 phage, a simulant for yellow fever virus and Hantaan virus, was propagated using as a host an E. coli strain with F pilus. MS2 phage genome was examined by reverse transcription and polymerase chain reaction (RT-PCR). Coat protein of the phage preparation was examined by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and mass spectrometric analysis. Cydia pomonella granulosis virus (CpGV) is a virus simulant candidate to smallpox virus. CpGV was isolated from a commercialized CpGV pellet. In this study, we developed new isolation and identification protocols for CpGV. One disadvantage of using CpGV is that it is not easy to determine viability of the virus. Here, we have included T4 phage as an alternative. We established a high titer production protocol and developed an easy genome identification protocol that does not require purified phage DNA. Stability of these virus preparations was also examined under various storage conditions. When the virus preparations were not subjected to freeze drying, MS2 phage was most stable when it was stored in liquid nitrogen but unstable at 4℃. In contrast, T4 phage was most stable when it was stored at 4℃. CpGV was stable at −20℃ but not at 4℃. Stability during or after freeze drying was also investigated. The result showed that 70~80% MS2 survived the freeze drying process. In contrast, only about 15% of T4 phage survived during the freeze drying. CpGV was found to be degraded during freeze drying.
Bacteriophage T4 ; Bacteriophages ; Biological Warfare Agents ; DNA ; Electrophoresis ; Freeze Drying ; Genome ; Granulovirus ; Hantaan virus ; Levivirus ; Nitrogen ; Polymerase Chain Reaction ; Reverse Transcription ; Variola virus ; Yellow fever virus