Biofilm removal by medical device cleaners: comparison of two bioreactor detection assays

R. Hadi, K. Vickery, A. Deva, T. Charlton

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Currently there are no standards for testing efficacy of medical device cleaners. With fears of prion transmission, residual protein on medical devices needs to be minimised. A bioreactor model was used to grow Pseudomonas aeruginosa biofilm on polytetrafluoroethylene coupons. The biofilm was subjected to various cleaners and residual biofilm was detected either by Crystal Violet assay (CrV) or a commercially available protein assay (PA) following hydrolysis of the biofilm. Percentage reduction of biofilm was compared with untreated controls in three independent tests. There was no significant difference in percentage biofilm reduction irrespective of whether the CrV or PA was used to detect residual biofilm. Processing of coupons attached to the bioreactor rod and position of coupon within the rod had no significant effect on cleaning efficiency or detection of residual biofilm. Both within-run and between-run variation was very low for good cleaners such as 10 g/L NaOH, Zen, and 3 M Rapid Multi-Enzyme Cleaner (RMEC) 70500 but was higher for poor cleaners such as Tween 20 which removed less than 20% of the biofilm. Confocal microscopy and electron microscopy provided visual confirmation of the assay results. We propose that this method is suitable as a test method for evaluating the efficacy of surgical instrument cleaners in removing biofilm, as both within-run and between-run variation was low, detection of residual biofilm can be done using either CrV or PA, and the apparatus is easy to use, cheap and readily available.

LanguageEnglish
Pages160-167
Number of pages8
JournalJournal of Hospital Infection
Volume74
Issue number2
DOIs
Publication statusPublished - Feb 2010
Externally publishedYes

Fingerprint

Bioreactors
Biofilms
Equipment and Supplies
Gentian Violet
Proteins
Polysorbates
Prions
Polytetrafluoroethylene
Surgical Instruments
Confocal Microscopy
Pseudomonas aeruginosa
Fear
Electron Microscopy
Hydrolysis

Cite this

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abstract = "Currently there are no standards for testing efficacy of medical device cleaners. With fears of prion transmission, residual protein on medical devices needs to be minimised. A bioreactor model was used to grow Pseudomonas aeruginosa biofilm on polytetrafluoroethylene coupons. The biofilm was subjected to various cleaners and residual biofilm was detected either by Crystal Violet assay (CrV) or a commercially available protein assay (PA) following hydrolysis of the biofilm. Percentage reduction of biofilm was compared with untreated controls in three independent tests. There was no significant difference in percentage biofilm reduction irrespective of whether the CrV or PA was used to detect residual biofilm. Processing of coupons attached to the bioreactor rod and position of coupon within the rod had no significant effect on cleaning efficiency or detection of residual biofilm. Both within-run and between-run variation was very low for good cleaners such as 10 g/L NaOH, Zen, and 3 M Rapid Multi-Enzyme Cleaner (RMEC) 70500 but was higher for poor cleaners such as Tween 20 which removed less than 20{\%} of the biofilm. Confocal microscopy and electron microscopy provided visual confirmation of the assay results. We propose that this method is suitable as a test method for evaluating the efficacy of surgical instrument cleaners in removing biofilm, as both within-run and between-run variation was low, detection of residual biofilm can be done using either CrV or PA, and the apparatus is easy to use, cheap and readily available.",
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Biofilm removal by medical device cleaners : comparison of two bioreactor detection assays. / Hadi, R.; Vickery, K.; Deva, A.; Charlton, T.

In: Journal of Hospital Infection, Vol. 74, No. 2, 02.2010, p. 160-167.

Research output: Contribution to journalArticleResearchpeer-review

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