Isolation of
            <i>Legionella pneumophila</i>
            from Cooling Tower Water by Filtration

Orrison, L H; Cherry, William B.; David, Muniswamy

doi:10.1128/aem.41.5.1202-1205.1981

Cited by 39 publications

(22 citation statements)

References 14 publications

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“…Some previous researchers compared the recovery of membranes of different materials and pore sizes for Legionella spp. with the concentration and elution method, detecting the highest percentage of recovery with 0.2-µm vs. 0.45-µm pore-size filters [19,25].…”

Section: Discussionmentioning

confidence: 99%

“…Thus, microorganisms smaller than the filter pores, which one would expect to pass through the pores, have most likely remained trapped within the filter due to electrostatic forces rather than mechanical phenomena. In addition, to analyze samples that are difficult to filter for the turbidity, some authors and guidelines have recommended using membranes with larger pores to prevent clogging or reduced flow [16,25,30] that would reduce the microorganism recovery by the filter.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Legionella Detection in Water Networks as per ISO 11731:2017: Can Different Filter Pore Sizes and Direct Placement on Culture Media Influence Laboratory Results?

Giglio

Diella

Trerotoli

et al. 2020

IJERPH

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Determination of Legionella concentrations in water networks is useful for predicting legionellosis risks. The standard culture technique using concentration with membranes filters is the most commonly used method for environmental surveillance of Legionella. The aim of this study was to verify whether filtration with different filter pore sizes (0.2 and 0.45 µm) according to (ISO) 11731:2017, followed by directly placing them on culture media, can influence Legionella detection. Three laboratories participated in an experimental study that tested a known suspension of Legionella pneumophila (Lpn) serogroup 1 (ATCC 33152) (approximate final cell density of 15 CFU/mL). E. coli (ATCC 11775) and Pseudomonas aeruginosa (ATCC 25668) were included as control tests. The average (95% CI) percentage of recovery of Lpn was 65% using 0.45-µm filters and 15% using 0.2-µm filters (p < 0.0001). For control tests, the average (95% CI) percentage of recovery was higher with 0.45 vs. 0.2 µm filters: 97% vs. 64% for Escherichia coli (p < 0.00001) and 105% vs. 97% (p = 0.0244) for P. aeruginosa. Our results showed that the 0.45-µm filters provided the greatest detection of Legionella. Because the current national guidelines leave the choice of membrane porosity to the operator, experimental studies are important for directing operators towards a conscious choice to standardize Legionella environmental surveillance methods.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Legionella Detection in Water Networks as per ISO 11731:2017: Can Different Filter Pore Sizes and Direct Placement on Culture Media Influence Laboratory Results?

Giglio

Diella

Trerotoli

et al. 2020

IJERPH

View full text Add to dashboard Cite

show abstract

“…These methods include fluorescent antibody staining, antigen detection, serological testing and polymerase chain reaction (PCR) [5,7]. Filtration, centrifugation, and immunomagnetic separation (IMS) techniques can be used to concentrate bacteria and are often necessary in order to achieve a higher detectability of the pathogens and to condition the samples [8][9][10]. Pre-purification steps are essential in the separation of Legionella from greywater [11].…”

Section: Introductionmentioning

confidence: 99%

Immunomagnetic Separation of Microorganisms with Iron Oxide Nanoparticles

et al. 2020

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The early detection of Legionella in water reservoirs, and the prevention of their often fatal diseases, requires the development of rapid and reliable detection processes. A method for the magnetic separation (MS) of Legionella pneumophila by superparamagnetic iron oxide nanoparticles is developed, which represents the basis for future bacteria detection kits. The focus lies on the separation process and the simplicity of using magnetic nanomaterials. Iron oxide nanoparticles are functionalized with epoxy groups and Legionella-specific antibodies are immobilized. The resulting complexes are characterized with infrared spectroscopy and tested for the specific separation and enrichment of the selected microorganisms. The cell-particle complexes can be isolated in a magnetic field and detected with conventional methods such as fluorescence detection. A nonspecific enrichment of bacteria is also possible by using bare iron oxide nanoparticles (BIONs), which we used as a reference to the nanoparticles with immobilized antibodies. Furthermore, the immunomagnetic separation can be applied for the detection of multiple other microorganisms and thus might pave the way for simpler bacterial diagnosis.

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“…The method of membrane filtration is essentially a modification of that described by Orrison, Cherry & Milan (1981). The most likely modification in general use is that shredding of the filter with scissors and mixing is used rather than a blender to fragment the filter.…”

Section: Discussionmentioning

confidence: 99%

Legionella pneumophila: comparison of isolation from water specimens by centrifugation and filtration

1987

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SUMMARYA comparison was made between membrane filtration and centrifugation for the isolation of Legionella pneumophila from seeded water samples. Using samples of varying concentration, the optimum speed and time of centrifugation were determined and the relationship between the number of organisms present in the water and the proportion recovered was examined. Following this, sequential routine environmental waters were filtered and centrifuged in parallel.Centrifugation and filtration using nitrocellulose filters were found to be comparable. The optimum speed and time of centrifugation was approximately 6000 g for 10 min. There was a constant proportion of viable organisms recovered irrespective of the concentration in the unspun samples.

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Isolation of Legionella pneumophila from Cooling Tower Water by Filtration

Cited by 39 publications

References 14 publications

Legionella Detection in Water Networks as per ISO 11731:2017: Can Different Filter Pore Sizes and Direct Placement on Culture Media Influence Laboratory Results?

Legionella Detection in Water Networks as per ISO 11731:2017: Can Different Filter Pore Sizes and Direct Placement on Culture Media Influence Laboratory Results?

Immunomagnetic Separation of Microorganisms with Iron Oxide Nanoparticles

Legionella pneumophila: comparison of isolation from water specimens by centrifugation and filtration

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