Limits...
Evaluation of three swabbing devices for detection of Listeria monocytogenes on different types of food contact surfaces.

Lahou E, Uyttendaele M - Int J Environ Res Public Health (2014)

Bottom Line: A cocktail of four L. monocytogenes serotypes was inoculated with a concentration of 100 CFU/250 cm2 onto stainless steel (SS), high density polyethylene (HDPE) and rubber surfaces in a 250 cm2 area.All devices were capable to detect the contamination immediately after inoculation.The detection ability of the different devices for L. monocytogenes can be concluded to be rather high on different types of food contact surfaces.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Food Microbiology and Food Preservation, Department of Food Safety and Food Quality, Ghent University, Coupure Links 653, Ghent 9000, Belgium. evy.lahou@ugent.be.

ABSTRACT
Listeria monocytogenes can adhere to different types of food contact surfaces within a food processing environment. Therefore, environmental sampling devices should be capable of detecting unacceptable contamination. In this study, a sponge-stick, foam spatula and an environmental swab were evaluated on their ability to detect low concentrations of L. monocytogenes on different types of food contact surfaces. A cocktail of four L. monocytogenes serotypes was inoculated with a concentration of 100 CFU/250 cm2 onto stainless steel (SS), high density polyethylene (HDPE) and rubber surfaces in a 250 cm2 area. Immediately after inoculation and after 1 h exposure, the surfaces were swabbed with the different swabbing devices. The results of the study show only minor differences in the ability of the swabbing devices to detect L. monocytogenes. All devices were capable to detect the contamination immediately after inoculation. However, when the surfaces were allowed to air-dry for 1 h, L. monocytogenes was undetected in 11.1% of the samples (n = 27) with the sponge stick, in 7.4% of the samples (n = 27) with the foam spatula and in 3.7% of the samples (n = 27) with the environmental swab, especially on SS surfaces. The detection ability of the different devices for L. monocytogenes can be concluded to be rather high on different types of food contact surfaces.

Show MeSH

Related in: MedlinePlus

This figure shows the technique of swabbing with an overlapping “S” pattern. The tip of the swab/sponge can be used to wipe the perimeter of the sampling area, resulting in an optimal use of the swab/sponge surface.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3924475&req=5

ijerph-11-00804-f001: This figure shows the technique of swabbing with an overlapping “S” pattern. The tip of the swab/sponge can be used to wipe the perimeter of the sampling area, resulting in an optimal use of the swab/sponge surface.

Mentions: An envelope containing a pre-moistened sponge stick was opened and the stick was aseptically removed. Swabbing was performed using an overlapping “S” pattern to cover the entire surface with horizontal strokes. Next, the swab was rotated and the same area was swabbed again using vertical “S”-strokes followed by swabbing using diagonal “S”-strokes. The tip of the device was used to wipe the perimeter of the sampling area (Figure 1). The sponge-stick was placed into the bag and the stick was bending to break off, allowing the sponge to drop in to the bag. The sponge was enriched with 225 mL of half fraser broth (Biomérieux, Brussels, Belgium) and subsequently incubated for 24 ± 2 h at 30 °C. An aliquot of 0.1 mL was spread on ALOA agar and incubated for 24 ± 2 h at 37 °C.


Evaluation of three swabbing devices for detection of Listeria monocytogenes on different types of food contact surfaces.

Lahou E, Uyttendaele M - Int J Environ Res Public Health (2014)

This figure shows the technique of swabbing with an overlapping “S” pattern. The tip of the swab/sponge can be used to wipe the perimeter of the sampling area, resulting in an optimal use of the swab/sponge surface.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3924475&req=5

ijerph-11-00804-f001: This figure shows the technique of swabbing with an overlapping “S” pattern. The tip of the swab/sponge can be used to wipe the perimeter of the sampling area, resulting in an optimal use of the swab/sponge surface.
Mentions: An envelope containing a pre-moistened sponge stick was opened and the stick was aseptically removed. Swabbing was performed using an overlapping “S” pattern to cover the entire surface with horizontal strokes. Next, the swab was rotated and the same area was swabbed again using vertical “S”-strokes followed by swabbing using diagonal “S”-strokes. The tip of the device was used to wipe the perimeter of the sampling area (Figure 1). The sponge-stick was placed into the bag and the stick was bending to break off, allowing the sponge to drop in to the bag. The sponge was enriched with 225 mL of half fraser broth (Biomérieux, Brussels, Belgium) and subsequently incubated for 24 ± 2 h at 30 °C. An aliquot of 0.1 mL was spread on ALOA agar and incubated for 24 ± 2 h at 37 °C.

Bottom Line: A cocktail of four L. monocytogenes serotypes was inoculated with a concentration of 100 CFU/250 cm2 onto stainless steel (SS), high density polyethylene (HDPE) and rubber surfaces in a 250 cm2 area.All devices were capable to detect the contamination immediately after inoculation.The detection ability of the different devices for L. monocytogenes can be concluded to be rather high on different types of food contact surfaces.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Food Microbiology and Food Preservation, Department of Food Safety and Food Quality, Ghent University, Coupure Links 653, Ghent 9000, Belgium. evy.lahou@ugent.be.

ABSTRACT
Listeria monocytogenes can adhere to different types of food contact surfaces within a food processing environment. Therefore, environmental sampling devices should be capable of detecting unacceptable contamination. In this study, a sponge-stick, foam spatula and an environmental swab were evaluated on their ability to detect low concentrations of L. monocytogenes on different types of food contact surfaces. A cocktail of four L. monocytogenes serotypes was inoculated with a concentration of 100 CFU/250 cm2 onto stainless steel (SS), high density polyethylene (HDPE) and rubber surfaces in a 250 cm2 area. Immediately after inoculation and after 1 h exposure, the surfaces were swabbed with the different swabbing devices. The results of the study show only minor differences in the ability of the swabbing devices to detect L. monocytogenes. All devices were capable to detect the contamination immediately after inoculation. However, when the surfaces were allowed to air-dry for 1 h, L. monocytogenes was undetected in 11.1% of the samples (n = 27) with the sponge stick, in 7.4% of the samples (n = 27) with the foam spatula and in 3.7% of the samples (n = 27) with the environmental swab, especially on SS surfaces. The detection ability of the different devices for L. monocytogenes can be concluded to be rather high on different types of food contact surfaces.

Show MeSH
Related in: MedlinePlus