J Med Microbiol 56 (2007), 250-254; DOI: 10.1099/jmm.0.46935-0
© 2007 Society for General Microbiology
ISSN 1473-5644
Growth in catheter biofilms and antibiotic resistance of Mycobacterium avium
Joseph O. Falkinham, III
Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
Correspondence
Joseph O. Falkinham III
jofiii{at}vt.edu
Received 7 September 2006
Accepted 25 October 2006
Cells of Mycobacterium avium strain A5 adhered to plasticized polyvinyl chloride catheter tubing and grew at low nutrient concentration, consistent with reports of catheter-associated M. avium infection. Starting with initial cell densities of 12x106 c.f.u. ml1, biofilms of approximately 350 c.f.u. cm2 formed within 24 h at room temperature. Growth rates of cells in biofilms were exponential and equal to 2.45 days doubling time. Rates were exponential for 12 weeks incubation and reached cell densities of 6.5x104 c.f.u. cm2 by 4 weeks. Cells grown in catheter biofilms were significantly more resistant to clarithromycin and rifamycin than cells grown in suspension.
Copyright © 2007 Society for General Microbiology.