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ANNUAL CONFERENCE :: Abstract Library
Abstract Library
2003 Conference Abstract
| Type of Submission |
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Submission Type: |
Poster Presentation |
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Subject Category: |
Applied Microbiology |
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| Session Information |
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Presentation Date: |
May 26, 2003 |
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Abstract ID: |
A31 |
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Session: |
Poster 1 |
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Time: |
14:00 |
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| Presenting Author |
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M VEILLETTE, Centre de recherche de l’hôpital Laval, institue universitaire de cardiologie et de pneumologie de l’Université Laval Québec, Canada
marc.veillette@crhl.ulaval.ca |
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| Other Authors |
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C DUCHAINE, Centre de recherche de l’hôpital Laval, institue universitaire de cardiologie et de pneumologie de l’Université Laval Québec, Canada
PS THORNE, University of Iowa, Iowa City IA, USA
T GORDON, NYU Medical Center, Tuxedo, NY, USA
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| Title |
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Six months follow-up of microbial contamination in a metal-working fluid system after dumping, cleaning and recharging |
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| Abstract Text |
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Rationale : Large volumes of metal-working fluids (MWF) are used in automobile industries for cooling and lubrication of metal pieces and tools during machining. MWF accumulate microbial growth through continuous re-circulation and re-use. We studied the progression of the microbial contamination for 6 months after dumping, cleaning and recharging of a large semi-synthetic MWF system managed with several biocides. Methods : Fresh, uncontaminated fluid was added to the system after the cleaning. The following samples were collected and analyzed : in-use fluid (before the system cleaning), neat fluid diluted to 6% with water, and in-use MWF 12 hours, 1,3 and 6 months post cleaning. Samples were studied for total microorganisms count, viability assessment, plate count on various media (blood agar, R2A, TSA, Middlebrooks, rose bengal and malt extract agar in aerobic conditions ; blood agar and R2A in anaerobic conditions), and Mycobacteria detection by PCR. Results : There a quick progression in the total bacterial count : 5.7x107 cells /ml in the pre-change used fluid, no bacteria in the neat fluid, 6.9x106 cells/ml after 12 hours and 2.2x106, 3.6x108 and 6.1x108 cells/ml, after 1,3 and 6 months respectively with less than 1 % viability. On average, only 0.2% of the total counts were recovered on R2A cultures. PCR showed the presence of Mycobacteria in the the used, 3 and 6 months fluid. Mycobacteria were also identified from Middlebrooks and R2A cultures with added antibiotics. Conclusion : The standard approach to cleaning MWF systems should be revisited since residual bacteria can re-populate the system rapidly. |
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