Detection of Legionella pneumophila serogroup 7 strain from bathwater samples in a Japanese hospital

Shigeru Fujimura, Tomohiro Oka, Osamu Tooi, Miho Meguro, Miyuki Chiba, Masato Kawamura, Fumi Maki, Hiroaki Takeda, Akira Watanabe

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


Hospital-acquired legionellosis is one of the serious problems in nosocomial infection. For risk assessment of nosocomial Legionella infection, we surveyed samples from bathrooms for public use in three hospitals and two nursing homes to determine whether Legionella pneumophila was present. A total of 70 hot bathwater samples and samples wiped from bathtubs were collected at 1-h intervals. Fifteen shower-water and 15 inner-head samples were obtained at the start of a bath. Water samples were cultured using the Legionella spp. selective medium, and discrimination between L. pneumophila and other Legionella spp. was performed by PCR analysis. L. pneumophila serogroup 7 was detected in 1 bathwater and 1 wiped sample, both of which were collected 1 h after daily use from the same bathtub in a hospital. However, L. pneumophila SG7 was not detected in any other samples. Furthermore, the concentrations of free residual chlorine in most bath- and shower-water samples were lower than 0.1 mg/l. These results suggest that L. pneumophila has become a potential pathogen for nosocomial infections in public-type hospital baths. From the point of view of an infection-control program, it might be advisable to hold the concentration of free residual chlorine at 0.2-0.4 mg/l, which is generally required for public baths in Japan.

Original languageEnglish
Pages (from-to)105-108
Number of pages4
JournalJournal of Infection and Chemotherapy
Issue number2
Publication statusPublished - 2006 Apr
Externally publishedYes


  • Bathwater
  • Hospital
  • Legionella pneumophila
  • Nursing home

ASJC Scopus subject areas

  • Microbiology (medical)
  • Infectious Diseases
  • Pharmacology (medical)


Dive into the research topics of 'Detection of Legionella pneumophila serogroup 7 strain from bathwater samples in a Japanese hospital'. Together they form a unique fingerprint.

Cite this