Effects of nutritional and ambient oxygen condition on biofilm formation in Mycobacterium avium subsp. hominissuis via altered glycolipid expression.
Mycobacterium avium subsp. hominissuis (MAH) is the major causative agent of nontuberculous mycobacteriosis, the representative case of environment-related infectious diseases the incidence of which is increasing in industrialized countries. MAH is found in biofilm in drinking water distribution system and residential environments. We investigated the effect of gaseous and nutritional conditions, and the role of glycopeptidolipids (GPLs) on biofilm-like pellicle formation in MAH. Pellicle formation was observed under 5% oxygen in Middlebrook 7H9 broth containing 0.2% glycerol and 10% albumin-dextrose-catalase enrichment but not under normoxia or in nutrient-poor media. An analysis of 17 environmental isolates revealed that hypoxia (5% oxygen) preferentially enhanced pellicle formation both in plastic plates and in glass tubes, compared with hypercapnia (5% carbon dioxide). Wild-type strains (WT) developed much thicker pellicles than GPL-deficient rough mutants (RM). WT bacterial cells distributed randomly and individually in contrast to that RM cells positioned linearly in a definite order. Exogenous supplementation of GPLs thickened the pellicles of RM, resulting in a similar morphological pattern to WT. These data suggest a significant implication of eutrophication and hypoxia in biofilm-like pellicle formation, and a functional role of GPLs on development of pellicles in MAH.
Department of Bacteriology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.
Takahiro
T
Totani
Toneyama Institute for Tuberculosis Research, Osaka City University Medical School, 5-1-1, Toneyama, Toyonaka, Osaka, 560-8552, Japan.
Yukiko
Y
Nishiuchi
Department of Bacteriology, Graduate School of Medical and Dental Sciences, Niigata University, 1-757, Asahimachi-Dori, Chuo-ku, Niigata, 951-8510, Japan.
Yoshitaka
Y
Tateishi
Department of Structural Pathology, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-Dori, Chuo-ku, Niigata, 951-8510, Japan.
Yutaka
Y
Yoshida
Department of Bacteriology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.
Hiromi
H
Kitanaka
Department of Bacteriology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.
Mamiko
M
Niki
Department of Bacteriology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.
Yukihiro
Y
Kaneko
Department of Bacteriology, Graduate School of Medical and Dental Sciences, Niigata University, 1-757, Asahimachi-Dori, Chuo-ku, Niigata, 951-8510, Japan.
Sohkichi
S
Matsumoto
D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D004202:Disinfectants / Q000494:pharmacology; D004777:Environment; D004783:Environmental Microbiology; D006017:Glycolipids / Q000378:metabolism*; D006801:Humans; D000860:Hypoxia; D009154:Mutation; D009165:Mycobacterium Infections, Nontuberculous / Q000382:microbiology*; D009162:Mycobacterium avium / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D009747:Nutritional Physiological Phenomena; D010101:Oxygen Consumption; D010641:Phenotype
D004202:Disinfectants; D006017:Glycolipids