Isolation of non-tuberculosis mycobacteria in treated dental unit waterlines☆
Received 14 November 2003; received in revised form 31 December 2003; accepted 2 February 2004.
Abstract
Objective
The purpose of the study was to investigate the presence of non-tuberculosis mycobacteria (NTM) in dental unit waterlines that were being routinely treated with an intermittent use waterline cleaner.
Study design
The study was conducted at a hospital dentistry clinic where immunocompromised patients are seen. Water samples from two lines on one of two dental units were taken before and after routine weekend chemical treatment. Sampling was repeated on two subsequent occasions, on the same unit, at three monthly intervals. Laboratory techniques included centrifugation and membrane filtration to detect small numbers of organisms.
Results
Mycobacterium simiae was isolated from one of the four pre-treatment samples and from two of the four post-treatment samples. Mycobacterium mucogenicum was isolated from one of the four post-treatment samples.
Conclusions
This pilot study found that NTM were present in DUWLs that were being routinely treated with an intermittent use chemical cleaner. Practitioners are urged to understand the limitations of available DUWL treatments, and to consider the use of sterile water for non-surgical, as well as surgical, treatment of immunocompromised patients.
San Antonio, Tex THE UNIVERSITY OF TEXAS HEALTH SCIENCE CENTER AT SAN ANTONIO
aAssistant Professor, Department of Community Dentistry, University of Texas Health Science Center at San Antonio, Tex USA
bProfessor of General Dentistry, University of Texas Health Science Center at San Antonio USA
cProfessor of Pathology, University of Texas Health Science Center at San Antonio USA
Reprint requests: Dr. N. B. Porteous Assistant Professor Department of Community Dentistry 7703 Floyd Curl Drive San Antonio, Texas 78229 Fax: (210) 567-4587
☆ The study was supported by the Johnson & Johnson Fellowship in Infectious Diseases Control. The authors would like to express gratitude to Dr. Jeffrey Hicks, Associate Professor of General Dentistry, for his help with photography.
ABSTRACT