Open Access

Sanitization of an Automatic Reverse-Osmosis Watering System: Removal of a Clinically Significant Biofilm

Authors: Molk, Denise M1; Karr-May, Charlene L2; Trang, Elaine D2; Sanders, George E3

Source: Journal of the American Association for Laboratory Animal Science, Volume 52, Number 2, March 2013 , pp. 197-205(9)

Publisher: American Association for Laboratory Animal Science

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During environmental monitoring of our institution's rodent watering systems, one vivarium was found to have high bacterial loads in the reverse-osmosis (RO) automatic water system. These findings prompted evaluation of the entire RO water production and distribution system. Investigation revealed insufficient rack and RO system sanitization, leading to heavy biofilm accumulation within the system. Approximately 2 wk after discovery in the water system, one of the bacterial organisms isolated in the water supply, Sphingomonas paucimobilis, was isolated from a peritoneal abscess of a severely immunodeficient B6. Cg-Slc11a1r Rag1 tm1Mom /Cwi mouse housed in the same vivarium, suggesting that rodents drinking from this system were being exposed randomly to fragments of biofilm. Plans were developed to sanitize the entire system. Hypercholorination was used first, followed by treatment with a combination of peracetic acid and hydrogen peroxide. Between system sanitizations, a low-level chlorine infusion was added to the system as a biocide. Heterotrophic plate counts and bacterial isolation were performed on water samples obtained before and after sanitization procedures. We here discuss the process of identifying and correcting this important water-quality issue.

Document Type: Case Report

Affiliations: 1: Department of Comparative Medicine, University of Washington, USA. 2: Department of Comparative Medicine, University of Washington, USA 3: Department of Comparative Medicine, University of Washington, USA; US Geological Survey, Western Fisheries Research Center, Seattle, Washington, USA

Publication date: March 1, 2013

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  • The Journal of the American Association for Laboratory Animal Science (JAALAS) serves as an official communication vehicle for the American Association for Laboratory Animal Science (AALAS). The journal includes a section of refereed articles and a section of AALAS association news. The mission of the refereed section of the journal is to disseminate high-quality, peer-reviewed information on animal biology, technology, facility operations, management, and compliance as relevant to the AALAS membership. JAALAS accepts research reports (data-based) or scholarly reports (literature-based), with the caveat that all articles, including solicited manuscripts, must include appropriate references and must undergo peer review.

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