Hostname: page-component-8448b6f56d-tj2md Total loading time: 0 Render date: 2024-04-25T04:56:14.968Z Has data issue: false hasContentIssue false

Simulated-Use Polytetrafluorethylene Biofilm Model: Repeated Rounds of Complete Reprocessing Lead to Accumulation of Organic Debris and Viable Bacteria

Published online by Cambridge University Press:  17 October 2017

Michelle J. Alfa*
Affiliation:
St Boniface Research Center, Winnipeg, Manitoba, Canada Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
Harminder Singh
Affiliation:
Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
Zoann Nugent
Affiliation:
Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
Donald Duerksen
Affiliation:
Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
Gale Schultz
Affiliation:
Winnipeg Regional Health Authority, Winnipeg, Manitoba, Canada
Carol Reidy
Affiliation:
St Boniface Hospital, Winnipeg, Manitoba, Canada
Pat DeGagne
Affiliation:
St Boniface Research Center, Winnipeg, Manitoba, Canada
Nancy Olson
Affiliation:
St Boniface Research Center, Winnipeg, Manitoba, Canada
*
Address correspondence to Dr Michelle J Alfa, St. Boniface Research Centre, 351 Tache Ave, Winnipeg, Manitoba, Canada, R2H 2A6 (malfa@sbrc.ca).

Abstract

OBJECTIVE

Biofilm has been implicated in bacterial persistence and survival after endoscope reprocessing. In this study, we assessed the impact of different methods of reprocessing on organic residues and viable bacteria after repeated rounds of biofilm formation when each was followed by full reprocessing.

METHODS

ATS-2015, an artificial test soil containing 5–8 Log10 colony-forming units (CFU) of Enterococcus faecalis and Pseudomonas aeruginosa, was used to form biofilm in polytetrafluroethylene channels overnight on 5 successive days. Each successive day, full pump-assisted cleaning using bristle brushes or pull-through devices in combination with enzymatic or nonenzymatic detergents followed by fully automated endoscope reprocessor disinfection using peracetic acid was performed. Residuals were visualized by scanning electron microscopy (SEM). Destructive testing was used to assess expected cutoffs for adenosine triphosphate (ATP; <200 relative light units), protein (<2 µg/cm2), and viable bacteria count (0 CFU).

RESULTS

Protein residuals were above 2 µg/cm2, but ATP residuals were <200 relative light units for all methods tested. Only when enzymatic cleaner was used for cleaning were there no viable bacteria detected after disinfection irrespective of whether bristle brushes or pull-through devices were used. SEM revealed that some residual debris remained after all reprocessing methods, but more residuals were detected when a nonenzymatic detergent was used.

CONCLUSIONS

Surviving E. faecalis and P. aeruginosa were only detected when the non-enzymatic detergent was used, emphasizing the importance of the detergent used for endoscope channel reprocessing. Preventing biofilm formation is critical because not all current reprocessing methods can reliably eliminate viable bacteria within the biofilm matrix.

Infect Control Hosp Epidemiol 2017;38:1284–1290

Type
Original Articles
Copyright
© 2017 by The Society for Healthcare Epidemiology of America. All rights reserved 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Reprocessing medical devices in health care settings: validation methods and labeling guidance for Industry and FDA staff. Food and Drug Administration (FDA) website. https://www.fda.gov/downloads/medicaldevices/deviceregulationandguidance/guidancedocuments/ucm253010.pdf. Published 2015. Accessed September 21, 2017.Google Scholar
2. American National Standard ST91: 2015 flexible and semi-rigid endoscope processing in health care facilities. Association for the Advancement of Medical Instrumentation website. https://my.aami.org/aamiresources/previewfiles/ST91_1504_preview.pdf. Published 2015. Accessed September 21, 2017.Google Scholar
3. Epstein, L, Hunter, JC, Arwady, MA, et al. New Delhi metallo-β-lactamase–producing carbapenem-resistant Escherichia coli associated with exposure to duodenoscopes. J Am Med Assoc 2014;312:14471455.Google Scholar
4. Preventable tragedies: superbugs and how ineffective monitoring of medical device safety fails patients. US Senate website. https://www.help.senate.gov/imo/media/doc/Duodenoscope%20Investigation%20FINAL%20Report.pdf. Published 2016. Accessed September 21, 2017.Google Scholar
5. Ross, AS, Baliga, C, Verma, P, et al. A quarantine process for the resolution of duodenoscope associated transmission of multidrug-resistant Escherichia coli . Gastrointest Endosc 2015;82:477483.Google Scholar
6. Brandabur, JJ, Leggett, JE, Wang, L, et al. Surveillance of guideline practices for duodenoscope and linear echoendoscope reprocessing in a large healthcare system. Gastrointest Endosc 2016;84:392399.e3.Google Scholar
7. Naryzhny, I, Silas, D, Chi, K. Impact of ethylene oxide gas sterilization of duodenoscopes after a carbapenem-resistant enterobacteriaceae outbreak. Gastrointest Endosc 2016;84:259262.Google Scholar
8. Alrabaa, SF, Nguyen, P, Sanderson, R, et al. Early identification and control of carbapenemase-producing Klebsiella pneumoniae, originating from contaminated endoscopic equipment. Am J Infect Control 2013;41:562564.Google Scholar
9. Olympus validates new reprocessing instructions for model TJF-Q180V duodenoscopes. Medical Device and Diagnostice Industry website. https://www.mddionline.com/olympus-validates-new-reprocessing-instructions. Published 2015. Accessed September 21, 2017.Google Scholar
10. Ofstead, CL, Wetzler, HP, Heymann, OL, Johnson, EA, Eiland, JE, Shaw, MJ. Longitudinal assessment of reprocessing effectiveness for colonoscopes and gastroscopes: results of visual inspections, biochemical markers, and microbial cultures. Am J Infect Control 2017;45:e26e33.Google Scholar
11. Alfa, MJ, Olson, N. Physical and composition characteristics of clinical secretions compared with test soils used for validation of flexible endoscope cleaning. J Hosp Infect 2016;93:83e88.Google Scholar
12. Pineau, L, De Philippe, E. Evaluation of endoscope cleanliness after reprocessing: a clinical-use study. Central Service 2013;1:2227.Google Scholar
13. Alfa, MJ, Olson, N, Murray, B-L. Comparison of clinically relevant benchmarks and channel sampling methods used to assess manual cleaning compliance for flexible gastrointestinal endoscopes. Am J Infect Control 2014;42:e1e5.Google Scholar
14. International Standards Organization/Technical Standard (ISO/TS) 15883-5: 2005 washer-disinfectors—part 5, test soils and methods for demonstrating cleaning efficacy. Annex E test soil and method for flexible endoscopes. Estonian Centre for Standardisation website. https://www.evs.ee/products/cen-iso-ts-15883-5-2005 Published 2005. Accessed September 21, 2017.Google Scholar
15. Alfa, MJ, DeGagne, P, Olson, N. Worst-case soiling levels for patient-used flexible endoscopes before and after cleaning. Am J Infect Control 1999;27:392401.Google Scholar
16. Verran, J, Boyd, RD. The relationship between substratum surface roughness ad microbiological and organic soiling: a review. Biofouling 2001;17:5971.Google Scholar
17. Balsamo, AC, Graziano, KU, Schneider, RP, Junior, MA, Lacerda, RA. Removing biofilm from an endoscopic: evaluation of disinfection methods currently used. Rev Esc Enferm USP 2012;46:9198.Google Scholar
18. Ren, W, Sheng, Z, Huang, X, Zhi, F, Cai, W. Evaluation of detergents and contact time on biofilm removal from flexible endoscopes. Am J Infect Control 2013;41:e89e92.Google Scholar
19. Herve, RC, Keevil, CW. Persistent residual contamination in endoscope channels; a fluorescence epimicroscopy study. Endoscopy 2016;48:609616.Google ScholarPubMed
20. Vickery, K, Ngo, QD, Zou, J, Cossart, E. The effect of multiple cycles of contamination, detergent washing, and disinfection on the development of biofilm in endoscope tubing. Am J Infect Control 2009;37:470475.Google Scholar
21. Ofstead, CL, Wetzler, HP, Doyle, EM, et al. Assessing residual contamination and damage inside flexible endoscopes over time. Am J Infect Control 2016;44:16751677.Google Scholar
22. Li, L, Mendis, N, Trigui, H, Oliver, JD, Faucher, SP. The importance of viable but non-culturable state in human bacterial pathogens. Frontiers Microbiol 2014;5:120.Google Scholar
23. Visrodia, K, Hanada, Y, Pennington, KM, Tosh, PK, Topazian, MD, Petersen, BT. Duodenoscope reprocessing surveillance with adenosine triphosphate testing and terminal cultures: a clinical pilot study. Gastrointest Endosc 2017;86:180186.Google Scholar
24. McDonnell, G, Ehrman, M, Kiess, S. Effectiveness of the SYSTEM 1E liquid chemical sterilant processing. Am J Infect Control 2016;4:685688.Google Scholar
25. Alfa, MJ, Ribeiro, MM, da Costa Luciano, C, Franc, R, Olson, N, DeGagne, P, Singh, H. A novel polytetrafluoroethylene-channel model, which simulates low levels of culturable bacteria in build-up biofilm after repeated endoscope reprocessing. Gastrointest Endosc 2017;86:442451.e1.Google Scholar