Microbiologia Medica (Mar 2010)
Micobatteriological control of diagnostic instrumentation
Abstract
Introduction: In addition to sterility testings for common bacteria, from 2006 on we have introduced in our laboratory sterility tests for mycobacteria on surgical instruments such as bronchoscope and lava-endoscope fluid used for their sterilization as well. Methods: Bronchology and Pneumology SUN departments, doing bronchoscopies, regularly send to our laboratory bronchoscopes washing fluids. Bronchology department also sends liquids used in lavaendoscopes. Our standard protocol consists of liquids inoculation directly on Lowenstein - Jensen (LJ) solid ground and on Middlebrook 7H9 liquid medium into Mgit test tubes, both produced by Becton Dickinson, within 42 days (1, 5, 6). Results: When growth of acid-alcohol resistant bacilli was detected, they were identified through probes or Accuprobe bioMérieux Inno- LIPA Mycobacteria by Innogenetics. All positivite results were related to M. Gordonae. As for the liquids examined, we found one positivite result in liquid medium in 2006 and none in 2007. On the contrary, in 2008 and the first 6 months of 2009, we have identified the following positive results: 2008 - 2009 (6m) LJ pos TOT 20 C. Lavaendoscope 8 V. 12 FBS We linked the positive findings on equipment with positivity for M. gordonae observed in patients undergoing bronchoscopy. Conclusions: Data analysis indicates within the period 2008-2009 we observed a recurring positivity for M. gordonae on equipment and therefore in some patients. On a careful evaluation, they showed no signs of clinical infection, also considering that this mycobacteria is usually a saprophyte (2, 3, 4). However, the protocol we adopted allowed us to recognize equipment contamination at birth and to urge fellow users to review sterilization protocols.
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