Comparison of membrane filters for recovery of legionellae from water samples

Smith, Lori; Carroll, Karen; Mottice, S

doi:10.1128/aem.59.1.344-346.1993

Cited by 32 publications

(25 citation statements)

References 5 publications

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“…Nonetheless, if only particulate 234 Th activity needs to be measured, both SUPOR and GN6 filters provide viable options with PALL mixed cellulose ester filter being the easier of the two in terms of subsampling for punches. However in terms of trace metal analysis the SUPOR filters are found to be most appropriate because of its high level of recovery, faster filtration rate, low blanks, and ease of handling (Smith et al 1993;Cullen and Sherrell 1999;Kiene and Linn 1999 ommend using QMA filters when 234 Th is applied as a tracer of POC flux in the water column and to use SUPOR filters when 234 Th is being applied as a tracer of trace metal flux and cycling in the water column. In studies where 234 Th needs to be applied as a tracer for both POC and trace metals, the choice of filter can be solved by modifying the single filter holder McLane pumps into dual filter-holder pumps where one filter holder is loaded with QMA filter and the other filter holder is loaded with SUPOR filter.…”

Section: Discussionmentioning

confidence: 99%

“…Unfortunately, the higher metal blanks associated with QMA filter make it a less than ideal filter for analyzing elements like 230 Th/ 231 Pa and Al. Based on previous work demonstrating the high level of recovery, faster filtration rate, low blanks, and ease of handling (Smith et al 1993;Cullen and Sherrell 1999;Kiene and Linn 1999) the TEI community had come to consensus to use polysulfone SUPOR filter as the filter of choice for TEI work during GEOTRACES intercalibration exercise. Because 234 Th can potentially be used to understand the cycling of trace metals in the upper ocean, it is imperative we test SUPOR filters along with QMA filters during this intercalibration exercise.…”

Section: Sampling Planmentioning

confidence: 99%

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Intercalibration studies of short‐lived thorium‐234 in the water column and marine particles

Maiti

Buesseler

Pike

et al. 2012

Limnology & Ocean Methods

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Intercomparision of 234 Th measurements in both water and particulate samples was carried out between 15 laboratories worldwide, as a part of GEOTRACES inter-calibration program. Particulate samples from four different stations namely BATS (both shallow and deep) and shelf station (shallow) in Atlantic and SAFE (both shallow and deep) and Santa Barbara station (shallow) in Pacific were used in the effort. Particulate intercalibration results indicate good agreement between all the participating labs with data from all labs falling within the 95% confidence interval around the mean for most instances. Filter type experiments indicate no significant differences in Th from decay and large in-growth corrections as a result of long gap between sample collection and processing.

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Section: Discussionmentioning

confidence: 99%

Section: Sampling Planmentioning

confidence: 99%

Intercalibration studies of short‐lived thorium‐234 in the water column and marine particles

Maiti

Buesseler

Pike

et al. 2012

Limnology & Ocean Methods

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“…The use of e.g. polysulphone filter instead of nylon filter may raise the recovery rate of legionellas when samples are concentrated by filtration (Smith et al 1993). Another useful concentration method of samples may be centrifugation (Brindle et al 1987), especially if the samples are very dirty.…”

Section: Discussionmentioning

confidence: 99%

Isolation of Legionella from water samples using various culture methods

Kusnetsov

Jousimies‐Somer²,

Nevalainen

et al. 1994

Journal of Applied Bacteriology

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The efficacy of a non-selective medium and two selective media were compared for the isolation of legionellas from water samples. The effect of acid wash treatment for decontamination of the water samples on the isolation frequency of legionellas was also studied. The 236 samples were taken from cooling, humidifying and drinking water systems; 21% were legionella-positive when inoculated directly on modified Wadowsky-Yee (MWY) medium and 26% were positive when concentrated (x 200) before cultivation on MWY or CCVC media. Inoculation on MWY medium after concentration followed by decontamination by the acid-wash technique gave the highest isolation frequency (31%). The lowest frequency (8%) was found with the non-selective BCYE alpha medium. An isolation frequency of 28% was achieved with the BCYE alpha medium after concentration and acid-wash treatment of the samples. Forty per cent of the samples were positive for legionellas when the results from all the culture methods were combined. Not all the legionella-positive samples were identified by a single culture method. Ninety-three of the 95 positive samples were detected with the two best combinations of three culture methods. The best culture method for detecting legionellas depended on the source of the water sample. Some water quality characteristics, like temperature and organic matter content, affected the isolation frequency of Legionella spp.

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“…In our tests, we observed that when loading and unloading the PC filters in the Button Samplers it was important to ensure that the filters were not wrinkled. Smith et al (1993) noted difficulty with PC filters in terms of static charges and problems with folding and wrinkling during filter loading. It should be noted that previous studies have found that gelatin filters dried out over time and were of limited use for long-term sampling (Burton et al, 2005, Tseng andLi, 2005a).…”

Section: Pressure Drop Measurementsmentioning

confidence: 99%

Physical Collection Efficiency of Filter Materials for Bacteria and Viruses

Burton

Grinshpun

Reponen

2006

The Annals of Occupational Hygiene

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The purpose of this study was to determine the physical collection efficiency of commercially available filters for collecting airborne bacteria, viruses, and other particles in the 10-900 nm (nanometer) size range. Laboratory experiments with various polytetrafluoroethylene (PTFE), polycarbonate (PC) and gelatin filters in conjunction with Button Inhalable samplers and three-piece cassettes were undertaken. Both biological and non-biological test aerosols were used: Bacillus atrophaeus, MS2, polystyrene latex (PSL), and sodium chloride (NaCl). The B.atrophaeus endospores had an aerodynamic diameter of 900 nm, whereas MS2 virion particles ranged from 10 to 80 nm. Monodisperse 350 nm PSL particles were used as this size was believed to have the lowest filtration efficiency. NaCl solution (1% weight by volume) was used to create a polydisperse aerosol in the 10-600 nm range. The physical collection efficiency was determined by measuring particle concentrations size-selectively upstream and downstream of the filters. The PTFE and gelatin filters showed excellent collection efficiency (>93%) for all of the test particles. The PC filters showed lower collection efficiency for small particles especially <100 nm. Among the tested filters, the lowest collection efficiencies, 49 and 22%, were observed for 1 and 3-microm pore size PC filters at the particle sizes of 47 and 63 nm, respectively. The results indicate that the effect of filter material is more significant for the size range of single virions than for bacteria. The effect of filter loading was examined by exposing filters to mixtures of PSL particles, which aimed at mimicking typical indoor dust levels and size distributions. A 4-h loading did not cause significant change in the physical collection efficiency of the tested filters.

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Comparison of membrane filters for recovery of legionellae from water samples

Cited by 32 publications

References 5 publications

Intercalibration studies of short‐lived thorium‐234 in the water column and marine particles

Intercalibration studies of short‐lived thorium‐234 in the water column and marine particles

Isolation of Legionella from water samples using various culture methods

Physical Collection Efficiency of Filter Materials for Bacteria and Viruses

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