title: [Physicochemical factors influencing distribution of Legionella species in Japanese hot springs].
abstract: We examined the relationship between the distribution of Legionella bacteria and various physicochemical characteristics of hot springs in Japan. Legionella bacteria were isolated from 52 (49.5%) out of 105 water samples, particularly from outdoor hot springs (67.3%). The bacterial count in the water samples positive for Legionella (86.5%) ranged from 10(1) to < 10(3) cfu/100 mL. L. pneumophila serogroup (SG) 4 (27.8%) was predominant in the water samples, followed by SG 5 (12.2%). The pulsefield gel electrophoresis (PFGE) patterns of chromosomal DNA for L. pneumophila SG 4 isolated from different parts of a hot spring resort were identical. Isolation of Legionella species from hot spring waters did not occur at pH 1.8-3.3, SO4(2-): > 780 mg/L, and H2SiO3: > 146 mg/L. The hot water-recirculating systems were applied to 18 out of 20 (90%) hot spring facilities which were found positive for Legionella. These results indicate that Legionella species are widespread in hot springs throughout Japan, except for waters with a low pH and non-recirculating waters, and that a single strain of L. pneumophila SG 4 is predominant in a particular hot spring resort.
authors.affiliation: Department of Microbiology and Parasitology, Kitasato University School of Medicine.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sasahara
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Kikuno
authors.forename: Shunji
authors.initials: S
authors.lastname: Okuda
authors.forename: Tomoko
authors.initials: T
authors.lastname: Sekiguchi
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Satoh
authors.forename: Yoko
authors.initials: Y
authors.lastname: Takayama
authors.forename: Masahito
authors.initials: M
authors.lastname: Aoki
authors.forename: Matsuhisa
authors.initials: M
authors.lastname: Inoue
mesh_terms: D045482:Hot Springs / Q000382:microbiology*; D007875:Legionella / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification*; D016952:Legionella pneumophila / Q000737:chemistry / Q000302:isolation & purification; D014871:Water Microbiology