Characterization of biofilm formation by clinical isolates of Mycobacterium avium

• Published in: Journal of medical microbiology Vol. 52; no. 9; pp. 747 - 752
• Main Authors: Carter, George, Wu, Martin, Drummond, Daryl C, Bermudez, Luiz E
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.09.2003; Society for General Microbiology
• Subjects: AIDS-Related Opportunistic Infections - microbiology; Biofilms - growth & development; Biological and medical sciences; Carbon - metabolism; Cations, Divalent - pharmacology; Chlorine Compounds - pharmacology; chloroheximide acetate; Culture Media, Conditioned - pharmacology; Disinfectants - pharmacology; Drug Resistance, Bacterial; Fundamental and applied biological sciences. Psychology; Glycoconjugates - analysis; Humans; Infectious diseases; Medical sciences; Microbial Sensitivity Tests; Microbiology; Molecular Sequence Data; Mycobacterium avium; Mycobacterium avium Complex - chemistry; Mycobacterium avium Complex - drug effects; Mycobacterium avium Complex - growth & development; Mycobacterium avium-intracellulare Infection - microbiology; Polyvinyl Chloride; potassium monopersulfate; Microbiology; Mycobacteriales; Mycobacteriaceae; Biofilm; Mycobacterium avium; Bacteria; Actinomycetes; Clinical isolate
• ISSN: 0022-2615; 1473-5644
• DOI: 10.1099/jmm.0.05224-0

1,2 Laboratory of Bacterial Pathogenesis, Kuzell Institute 1 and Liposome Research Laboratory 2 , California Pacific Medical Center Research Institute, San Francisco, CA, USA 3 Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, 106 Dryden Hall, Corvallis, OR 97331-4804, USA 4 Department of Microbiology, College of Sciences, Oregon State University, Corvallis, OR, USA Correspondence Luiz E. Bermudez luiz.bermudez{at}oregonstate.edu Received February 19, 2003 Accepted May 23, 2003 Mycobacterium avium is an environmental organism encountered in natural and urban water sources as well as soil. M. avium biofilm has recently been identified on sauna walls and in city water pipes and might have a role in the survival of virulent strains in the environment and in the host. To characterize the M. avium biofilm, an in vitro model was adapted wherein biofilm develops on a PVC surface. Biofilm was detected by staining with crystal violet and visualization by optical microscopy and quantified by A 570 . M. avium strains MAC 101, MAC 100, MAC 104, MAC 109, MAC A5 and MAC 5501 (all isolated from the blood of AIDS patients) were used in the assays. Biofilm formation was dependent on the presence of Ca 2+ , Mg 2+ or Zn 2+ ions in the water, with the maximal effect seen at a concentration of 1 µM. The presence of 2 % glucose and peptone as sources of carbon increased the formation of biofilm, while this was partially inhibited by humic acid. Since sliding motility has been associated with the amount of glycopeptidolipid (GPL), TLC was used to determine the presence of GPL. The supernatant of a biofilm-forming culture induced formation of a stable biofilm and amikacin blocked the establishment of biofilm by M. avium strains at subinhibitory concentrations. Bacteria in the biofilm were more resistant to chlorine as well as to exposure to potassium monopersulfate and chloroheximide acetate than were planktonic bacteria. Identification of M. avium genes involved in biofilm formation and further studies of the effect of antimicrobials on the establishment of biofilm may identify approaches for inhibiting M. avium biofilm formation and colonization. Abbreviation: GPL, glycopeptidolipid.