Biofilm formation abilities and disinfectant-resistance of Pseudomonas aeruginosa isolated from cockroaches captured in hospitals.
Forty-five strains of Pseudomonas aeruginosa isolated from cockroaches captured in hospitals were investigated with regard to their biofilm-forming ability and resistance to various disinfectants in various cellular states. The hydrophobicity value varied among the test strains from 0.001 to 0.241, and the mean +/- standard deviation (SD) was 0.101 +/- 0.074. The relative viscosity of the extracellular product was measured. All test strains produced a mucous substance, and the value was 1.05-1.30 (mean +/- SD: 1.11 +/- 0.06), showing that all test strains had a biofilm-forming ability. Bactericidal experiments were performed using 6 disinfectants: ethanol, Hibitane, Isojin, Osvan, Tego 51, and Welpas. When bacteria in suspension were exposed to the disinfectants for 1 min (suspension test), 5 of the 6 disinfectants excluding Tego 51 completely killed all test strains, showing high bactericidal effects. In contrast, when adherent bacteria were exposed to the disinfectants for 1 min (adhesion test), the killing rate by Welpas was 100%, but those by Isojin and ethanol were lower (88.9 and 60.0%, respectively), that by Osvan was only 4.4%, and no bacteria were killed by Hibitane or Tego 51. These findings showed that the bactericidal effects markedly decreased in the case of adherent P. aeruginosa.
Saitou
Keiko
K
Graduate School of Environmental Health, Azabu University 1-17-71, Fuchinobe, Sagamihara, Kanagawa 229-8501, Japan.
Furuhata
Katsunori
K
Kawakami
Yasushi
Y
Fukuyama
Masafumi
M
D000818:Animals; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D003058:Cockroaches / Q000382:microbiology*; D004202:Disinfectants / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D004783:Environmental Microbiology; D006761:Hospitals; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000302:isolation & purification* / Q000472:pathogenicity / Q000502:physiology*; D014783:Viscosity
D004202:Disinfectants